Adult Hip and Pelvis Disorders

Abstract

Hip and pelvis pain are relatively common presenting complaints in adult patients. The diagnosis can be challenging as the patient may present with hip pain, groin pain or even pain referred to other areas. Additionally, due to overlapping pain patterns, injury or disease from nearby structures can refer pain to the hip and pelvis. The result is a large differential diagnosis which can appear daunting to the evaluating provider. As such, it is helpful to divide hip and pelvis pathology into anterior, lateral, and posterior causes of pain while remembering to include examinations of the abdomen, spine, and knee in appropriate cases. This chapter reviews the common musculoskeletal etiologies, associated symptoms, diagnostic evaluation, and treatment of adults presenting with hip and/or pelvis pain.

FormalPara Clinical Pearls

• Hip pain can originate from the hip joint, groin, surrounding musculature, sacroiliac joints, lumbar spine, abdomen, or pelvis.

• To ease in the clinical evaluation of hip pain, it is helpful to divide the hip and pelvis into anterior, lateral, and posterior regions.

• Asymptomatic labral tears are common in athletes. Do not refer an athlete with hip pain and a labral tear for surgical intervention until it has been confirmed that the femoroacetabular joint is the actual source of the patient’s pain.

• Athletic pubalgia should be considered in athletes with persistent hip, groin, or pelvic pain despite an adequate trial of conservative therapy.

6.1 Case Presentation

A 29-year-old male presents to your office with a complaint of intermittent hip pain for the last 18 months, which has been progressively getting worse over the last 2 weeks. He plays softball, baseball, and runs three to five miles several days a week. He also lifts weights 3 days a week. He denies any history of trauma. He states the pain occurred initially only with running and heavy exertion, but now it has progressed to occur with general ambulation. He admits to experiencing pain and tightness down the lateral side of his thigh to his knee. He denies weakness and tingling. He denies a snapping sensation. He denies systemic symptoms or incontinence of urine or stool. He has had no prior interventions besides rest, ice, and anti-inflammatory medication. Despite the above measures, when he returns to activity, the symptoms resurface.

Physical examination reveals no erythema, edema, or ecchymosis. He has normal, pain-free full range of motion of his hip although he experiences pain with terminal flexion, abduction, and external rotation. Palpation reveals tenderness over the greater trochanter, the tensor fascia lata, and the gluteus medius. He has negative log roll, flexion abduction external rotation (FABER), Gaenslen’s, Gillet, and piriformis tests. Strength is 5/5 with hip flexion, extension, and adduction. Abduction strength is 4+/5. He is neurovascular intact with normal sensation. He has a positive Ober test, Ely’s test, and Thomas test. Long sit test is normal. He has a compensated Trendelenburg on the affected side, but negative Stinchfield’s and fulcrum tests. He has mild pes planus bilaterally. No imaging studies are performed at this time.

6.2 Introduction

The human hip and pelvis are complex anatomical structures through which a great amount of energy passes during weight bearing and activity. As such, hip and pelvic injuries are common. Hip and pelvic pathology can present as hip pain, groin pain or can even be referred to other areas. Additionally, injury and disease from nearby structures can refer pain to the hip and pelvis. This produces an extensive differential diagnosis, which includes both musculoskeletal and non-musculoskeletal etiologies (Table 6.1). Furthermore, the evaluation is often made difficult because injuries may involve a variety of anatomical structures and may be acute, subacute, or chronic. This chapter reviews the common musculoskeletal etiologies of hip and pelvis pain, symptoms associated with these injuries, diagnostic evaluation, and treatment. The chapter divides hip and pelvis pathology into anterior, lateral, and posterior causes of pain (Table 6.2). The astute physician will remember to perform an examination of the abdomen, spine, knee, and other areas as appropriate because many problems outside the hip and pelvis refer pain to this area.

Table 6.1 Differential diagnosis of hip and pelvic pain

Table 6.2 Hip and pelvic pain diagnosis by anatomic region

6.3 Anterior Hip and Pelvis Pain

6.3.1 Adductor Strains and Tendinopathy

Adductor strains are generally referred to as a “pulled groin” and are a common cause of hip and groin pain in athletes. The adductor longus, adductor magnus, adductor brevis, adductor minimus, pectineus, and gracilis muscles are all adductors of the hip, contribute to hip flexion and extension, and contribute to internal and external rotation of the hip. In sport, the adductor longus is the most often injured, and may comprise up to 10 % of all athletic injuries [1, 2].

An acute adductor strain is caused by a sudden change in direction, sprinting, forced external rotation of an abducted leg, or powerful abduction stress during simultaneous adduction. Acute adductor strains are commonly seen in the sports of hockey and soccer because of the frequent cutting and frequent eccentric contraction of the adductors in these sports [2, 3]. Adductor tendinopathy is a mechanical enthesopathy generally due to repetitive strain injuries [4].

The differential diagnosis includes avascular necrosis of the femoral head, femoral neck stress fracture, iliopsoas bursitis, osteitis pubis, obturator nerve entrapment, osteoarthritis, pelvic stress fracture, inguinal hernia, and athletic pubalgia.

With an acute injury, athletes will complain of immediate pain piercing into the groin and an inability to continue activity. Delayed ecchymosis and soft tissue swelling may also occur. In chronic injury, athletes will report an insidious onset of groin pain, possibly starting after a change in training that is worse at the start of exercise. Severe pain and dysfunction that occur after a “pop” may suggest adductor tendon avulsion.

Physical examination will reveal tenderness to palpation along the subcutaneous border of the pubic ramus and along the involved adductor muscles and tendons. The patient will have pain with resisted adduction and with passive stretching.

The diagnosis of an adductor strain is usually made clinically. Plain radiographs can be helpful in excluding fractures or avulsions of the hip and pelvis. If the diagnosis is in question, musculoskeletal ultrasonography (Fig. 6.1) or magnetic resonance imaging (MRI) can be used to confirm the diagnosis and fully evaluate the degree of injury [4, 5].

Fig. 6.1

Musculoskeletal ultrasound long axis image of the origins of the adductor muscles on the pubic ramus. Note the separation of the superficial portion of the adductor longus from the pubic ramus (PR). AB adductor brevis, AL adductor longus. Arrows demonstrate partial thickness tear

Eccentric strengthening of the adductor muscles is an established preventative measure to protect against groin injuries in soccer players [6]. However, after the injury occurs, treatment depends on the severity of the symptoms. Initially, rest from aggravating factors for 1–2 weeks with ice and oral analgesics provides symptomatic relief. Athletes can begin a stretching program after the inflammation subsides. The goal of physical therapy is to prevent atrophy and to regain strength, flexibility, and endurance. Rehabilitative therapy should be instituted as soon as pain allows and should include isometric contractions without resistance followed by isometric contractions against resistance. Prevention and correction of predisposing biomechanical factors should be included in the rehabilitation program. Return to play may take 4 weeks to 6 months depending on the extent of injury. Shorts with directional compression may aid in preventing adductor strains and these shorts may reduce demand during rehabilitation after strains [7]. Athletes with chronic adductor longus strains that have failed several months of conservative therapy may be considered for platelet-rich plasma injection (PRP) [8]. Athletes with adductor avulsion injuries or with chronic tendinopathy that has failed more conservative measures should be referred to orthopedics for consideration for possible surgical intervention .

6.3.2 Quadriceps Strains

The quadriceps muscles are the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. The main action of the rectus femoris is to flex the hip and extend the knee, and it is the most commonly injured of the quadriceps muscles [9]. The quadriceps are heavily recruited and frequently overused during jumping, sprinting, cutting, skating, bicycling, and during other explosive movements. Injuries usually occur as a result of a heavy eccentric load. Quadriceps injuries are twice as common in the dominant leg, and risk factors for quadriceps injuries include short height and heavy weight, lack of flexibility, dry field conditions, and a history of quadriceps injuries [10]. The differential diagnosis includes femoral shaft stress fracture, acute compartment syndrome of the anterior thigh, meralgia paresthetica, and femoral nerve injury.

Athletes may report a sensation of “pulling” or “tearing” in the anterior hip with acute injury. Onset of pain is typically after forceful contraction of the quadriceps muscles. The pain is in the anterior thigh and occurs with knee extension or hip flexion. The pain often radiates down the thigh and into inguinal area. Physical examination may reveal pain with resisted hip flexion or resisted knee extension. There is often tenderness to palpation of the quadriceps muscles and a palpable defect or mass.

A rectus femoris strain is diagnosed clinically, but if an avulsion injury to the anterior inferior iliac spine is suspected then plain radiographs should be ordered . Ultrasonography (Fig. 6.2) and MRI can aid in the diagnosis and be used to determine severity.

Fig. 6.2

A long axis ultrasound view of a partial thickness tear of the vastus intermedius muscle. Arrows demonstrate the tear. F femur

Initial treatment consists of rest, ice, compression, oral analgesia, protected weight bearing, gentle range of motion, and quadriceps exercises. Ice massage and therapeutic ultrasound should be started early in the rehabilitation course. Rehabilitation strengthening exercises are initially concentric and progress to eccentric. An example of this progression is to start the athlete with backward walking, progress to backward running, and later transitioning to forward running. The athlete can return to running when his or her knee range of motion is 80 % that of the unaffected side. Depending on the severity of the injury, return to play may take 2–6 weeks. Data is currently lacking on evidence-based return to play protocols following quadriceps injury.

6.3.3 Quadriceps Contusion

Contusions of the quadriceps muscles are a common injury in contact sports including football, rugby, hockey, and martial arts. Quadriceps contusions are caused by direct trauma to the anterior thigh. The differential diagnosis includes femoral shaft fracture, acute compartment syndrome of the anterior thigh, meralgia paresthetica, and quadriceps strains.

Athletes will generally be able to give a history of trauma to the anterior thigh and will describe pain with passive knee flexion and active extension at the knee. Examination often reveals tenderness, swelling, and a hematoma on the anterior thigh. Pain with knee flexion and a loss of range of motion at the knee is often present on exam. If necessary, the diagnosis can be confirmed with musculoskeletal ultrasound, which will show disruption of the normal muscle fibers and hematoma formation.

Initial treatment is essentially the same as with quadriceps strains including rest, oral analgesia, elevation, and intermittent application of ice with a compression wrap. Keeping the muscle in a lengthened and flexed position for the first 24 h after injury can help maintain flexibility, decrease bleeding, and may shorten the time required for return to play [6]. The athlete should be allowed to weight bear as tolerated. Deep massage and ultrasound should be avoided, as these can increase muscle bleeding. Active flexio n should be encouraged and continued frequently. Heat and cold contrasts and strengthening exercises are initiated after the swelling begins to decrease. Return to play may be allowed after the athlete regains quadriceps flexibility and strength equal to 90 % of the unaffected side.

6.3.4 Myositis Ossificans

Myositis ossificans is a pseudosarcomatous lesion that is characterized by bone formation in or adjacent to muscle and can be a post-traumatic complication of a quadriceps contusion [11]. Post-traumatic myositis ossificans occurs after initial muscular bleeding leads to the formation of a hematoma, which later calcifies within the muscle. This process causes pain and reduced flexibility. The incidence of myositis ossificans following muscle contusion is 9–17 % [12]. Although occurrence after a contusion is the most common scenario reported by athletes, myositis ossificans can also develop in an athlete with a history of repetitive minor trauma.

The differential diagnosis includes hematoma, abscess, focal rhabdomyolysis, and malignant primary or secondary soft tissue tumors [13]. Post-traumatic myositis ossificans will become clinically suspected when an athlete does not respond to conservative interventions within 3–4 weeks after a contusion. The usual symptoms include a painful and palpable mass with progressive loss of range of motion.

On examination, the athlete may have an antalgic gait and a tender anterior leg mass. Plain radiographs are performed to evaluate the femur for fracture. A bone scan is often used to track myositis ossificans formation. Radiographic evidence of calcification due to myositis ossificans may not be present for weeks following injury and, therefore, a presumptive diagnosis of myositis ossificans is often made after a severe contusion does not show rapid improvement. To help differentiate late presenting myositis ossificans from a sarcoma, computed tomography (CT) scan or MRI is often utilized. Sonographic findings in myositis ossificans have also been described [14] (Fig. 6.3).

Fig. 6.3

A musculoskeletal ultrasound short axis (a) and long axis (b) views demonstrating heterotopic ossification within the vastus intermedius (VI) consistent with myositis ossificans (MO). RT right, RF rectus femoris, VL vastus lateralis, F femur. Arrows demonstrate myositis ossificans

Treatment of myositis ossificans is similar to that of a quadriceps strain. The goals of therapy are to restore strength and range of motion. Placing and holding the knee in end of range of flexion immediately after a significant contusion to the quadriceps may shorten the time to return to unrestricted full activity [10]. Early administration of indomethacin may aid in prevention of myositis ossificans; however, this concept is extrapolated from indomethacin’s use in prevention of heterotopic ossification following hip arthroplasty. At this time, it is uncertain if indomethacin has a substantial impact on the prevention of heterotopic bone formation following quadriceps contusion. Treatment with short term use of bisphosphonates has been suggested in the literature [15]; however, its use is limited by tetratogenicity. Additionally, once the drug is discontinued, the mineralization process appears to resume [16].

Early rehabilitation should include active stretching and strengthening exercises. Extracorporeal shock wave therapy may be considered in the treatment of myositis ossificans [17]. Surgical treatment generally is not indicated, but if necessary, it should be delayed until the mass has matured. Radiographic resolution is not necessary for return to play. However, rehabilitation to achieve full strength and flexibility is mandatory. Wearing protective padding over the affected area should be considered as well.

6.3.5 Iliopsoas Strain

The iliopsoas muscle is a strong flexor of the hip and can be acutely injured when the hip is forced into extension or is blocked during active flexion. This injury is commonly called a hip flexor strain. Tendinopathy may also occur with overuse. It often occurs in soccer players who are hit as they flex at the hip and extend at the knee to kick the ball. It also occurs in weightlifting, uphill running, and with sit-ups. The differential diagnosis includes adductor strains, quadriceps strains, femoroacetabular impingement, osteitis pubis, and athletic pubalgia.

Athletes present with a complaint of sharp, deep groin pain that worsens with active hip flexion or passive hip extension. Physical examination reveals tenderness to palpation in the femoral triangle and increased pain with resisted hip flexion and passive external rotation or extension. The diagnosis is made clinically and imaging is rarely needed. When the diagnosis is not clear, plain radiographs followed by MRI can help establish a diagnosis, with MRI able to distinguish between abnormalities of the involved bones, tendons, and muscles.

Initial treatment involves rest, protection, and oral analgesia followed by rehabilitation. In adults, this injury may result in a partial or complete tear at the musculotendinous junction and these tears take longer to rehabilitate. Corticosteroid injection and surgery may be considered in refractory cases [18].

6.3.6 Iliopsoas Bursitis

The iliopsoas tendon results from the joining of the iliacus and psoas muscles and inserts onto the lesser trochanter of the femur after passing over the protective iliopsoas bursa. The iliopsoas bursa is the largest bursa in the body and communicates with the hip joint in 15 % of athletes [19]. This bursitis is associated with sports requiring extensive use of the hip flexors (i.e., soccer, ballet, uphill running, hurdling, jumping) and may be particularly disabling for athletes. It is also associated with degenerative or inflammatory arthritis, infections, trauma, osteonecrosis, and hip replacement [20].

The differential diagnosis includes iliopsoas tendinopathy, FAI and labral tears, athletic pubalgia, AVN, and stress fractures of the femur and pelvis.

Athletes may present with severe, acute, deep groin pain radiating to the anterior hip or thigh. The pain may be great enough to disrupt ambulation. It is often associated with a snapping sensation caused by the iliopsoas tendon snapping over the iliopectineal eminence.

Athletes will assume a position of hip flexion and external rotation to obtain relief [21]. The musculotendinous junction of the iliopsoas lies in the femoral triangle, and deep palpation of the femoral triangle may elicit pain [19]. Pain may be exacerbated by passive hip extension or when the supine athlete raises his or her heels off the table approximately 15°, thereby isolating the iliopsoas [22]. Musculoskeletal ultrasonography will demonstrate an enlargement of the iliopsoas bursa [20] (Fig. 6.4), and MRI reveals a collection of fluid adjacent to the muscle in iliopsoas bursitis [23].

Fig. 6.4

Iliopsoas bursitis: A sagittal oblique view of the anterior hip demonstrates significant fluid within the iliopsoas bursa (open arrows). BUR bursa, AC acetabulum, FH femoral head

Treatment is almost always nonoperative and consists of rest, ice, nonsteroidal anti-inflammatories (NSAIDs), and stretching of the iliopsoas. If symptoms are recalcitrant to conservative therapy, corticosteroid injection with ultrasonographic (Fig. 6.5) or fluoroscopic guidance, release of the iliopsoas tendon near its insertion on the lesser trochanter, or excision of the bursa may be considered [19].

Fig. 6.5

Ultrasound guided aspiration of iliopsoas bursitis. A sagittal oblique view of the anterior hip was utilized to guide aspiration of the enlarged iliopsoas bursa from Fig. 6.4. The open arrow points to the needle used in the procedure. The asterisk demonstrates the medication that was injected following the aspiration. A acetabulum, FH femoral head

6.3.7 Rectus Abdominis Strain

The rectus abdominis originates on the pubis adjacent to the origin of the adductor longus . As such, injury to the rectus abdominis may easily be confused or coexist with an adductor injury.

The differential diagnosis includes intra-abdominal pathology, sexually transmitted diseases, inguinal hernia, adductor strain, and osteitis pubis.

Athletes typically report deep groin pain that is worsened by tightening or stretching of the rectus abdominis muscle. On physical examination, pain is elicited on palpation of the superior aspect of the pubic ramus, and is exacerbated in the supine patient by a bilateral straight leg raise or resisted sit-up. Imaging is generally not needed to make the diagnosis; however, if necessary, musculoskeletal ultrasound or MRI may demonstrate the injury.

Treatment includes relative rest and oral analgesia followed by activity modification with a physical therapy program that includes core stabilization. Local injection of anesthetic and corticosteroid can be considered in particularly painful cases or in recalcitrant cases, which the authors prefer to perform under ultrasound guidance [24].

6.3.8 Pubic Symphysis Dysfunction

The symphysis pubis plays a key role in energy dissipation and cushioning of impact forces during the human gait, and those forces multiply during sport causing biomechanical strain on the pubic symphysis [2]. Chronic pain at the pubis symphysis results from joint instability. This injury typically occurs in sports where high-speed cutting activity is common and is often present concurrently with an adductor strain. The disorder can also be seen in pregnancy, with widening of the pelvic joints occurring to allow passage of the infant through the pelvis during delivery [25].

The differential diagnosis of pubic symphysis pain includes osteitis pubis, inguinal hernia, athletic pubalgia, and pubic ramus stress fracture.

Athletes may complain of suprapubic pain that is worsened with walking, climbing stairs, turning in bed, getting up from a chair, or lifting. They may report suprapubic pain radiating to the groin or to the sacroiliac region and pain with urination.

The physical examination includes evaluation of the position of the pubic tubercles by palpating their borders to assess right-to-left variation in the frontal plane. Pubic symphysis dysfunction is present if the pubic bones are not level and tension of the two inguinal ligaments is asymmetric. Pain is also evoked by a lateral compression test. Rarely, a palpable groove at the level of the symphysis is detected. Conventional plain radiographs of the pelvis are often helpful in assessing pathologic widening of the symphysis. Flamingo view radiographs may aid in making the diagnosis and should be considered along with conventional plain radiographs. MRI will demonstrate soft tissue injuries and osseous edema and is the imaging study of choice [26].

Treatment i s traditionally conservatively with rest, oral analgesia, and pelvic support and compression. A graded exercise program including pelvic stabilization should be initiated as the patient tolerates. Symphyseal injections have also been shown to relieve pain. Referral for surgical intervention is appropriate if there is failure to improve with these conservative measures.

6.3.9 Osteitis Pubis

Osteitis pubis is a painful condition, generally caused by overuse in athletics , which affects the pubic symphysis and surrounding tendinous attachments. More recently, experts have differentiated osteitis pubis into three clinical entities specified as “pubic bone stress injury,” “symphysis pubis stress injury,” and “traumatic osteitis pubis.” [27] Osteitis pubis is commonly reported in sports requiring cutting, twisting, pivoting, excessive side-to-side motion, or multidirectional motions with frequent acceleration and deceleration [28]. For these reasons, osteitis pubis is common in athletics, and it is also common in pregnant and postpartum women, after urologic and gynecologic procedures, and in degenerative and rheumatologic conditions [29]. Athletes with reduced total hip range of motion, reduced hip abduction and adduction strength, and reduced trunk control may be at increased risk for the development of osteitis pubis [30].

The differential diagnosis of osteitis pubis includes pubic ramus stress fracture, pubic symphysis dysfunction, inguinal hernias, athletic pubalgia, proximal adductor pathology, and osteomyelitis.

Athletes describe a gradual onset of pain in the pubic region, which may radiate to the hip, groin, abdomen, proximal medial thigh, testes, and scrotum. The pain is often described as sharp, stabbing, or even burning. Athletes may report worsened pain with striding, pivoting, twisting, climbing stairs, kicking, sit-ups, leg raises, or Valsalva maneuvers. Athletes may also describe an audible or palpable clicking sensation at the symphysis [28].

Physical examination often reveals tenderness over the pubic symphysis and adductor origins of the inferior pubic ramus. Pain may be exaggerated with passive hip abduction, active hip flexion, or active adduction. The lateral pelvic compression and cross-leg tests are often positive. Trendelenburg’s test is often positive indicating weak hip abductors, and in severe cases, the athlete may have an antalgic gait with partially flexed hips and knees [28].

Plain radiographs of the pelvis should be obtained. It is important to note that radiographs can lag behind clinical symptoms by as much as 4 weeks. As the disease progresses, reactive sclerosis of the adjacent pubic bones, erosion and resorption of the symphysis margins, and widening of the joint space may appear on the radiographs [28]. If instability is suspected, one-legged standing flamingo views should be performed. Instability is defined as greater than two millimeter height difference between the superior rami of the symphysis [28]. MR I of the pelvis is the most detailed study and can be used to identify acute, subacute, and chronic osteitis pubis. However, marrow edema may be seen in asymptomatic patients, so clinical correlation is necessary to make the diagnosis [1, 27].

Various treatment options for osteitis pubis have been suggested, but most programs start with rest and pharmacologic pain reduction. The goal is to reduce inflammation and remove the provocative activity by modifying training. Athletes should decrease mileage, prevent over-striding, and eliminate downhill running. Oral corticosteroids can be used if the athlete demonstrates intense pain that is limiting their ability to participate in a rehabilitative program [28]. Ultrasound or fluoroscopic guided corticosteroid injection into and around the pubic symphysis may be considered in athletes with refractory symptoms [29]. However, prior to injection, laboratory evaluation should be performed to evaluate for osteomyelitis as a possible cause [27]. A structured physical therapy program should begin when pain and inflammation are reduced. Modalities such as ultrasound and phonophoresis may assist with pain reduction. Leg length discrepancy should also be corrected if found. A graduated exercise program should be utilized with the goal of returning the athlete to a preinjury level of participation. However, patience is required, as this may take 3–6 months or longer, and time to return to play correlates well with the athlete’s experienced level of dysfunction [30]. Compression shorts may reduce pain during and after the rehabilitation program. Surgical interventions may be considered if the athlete fails to improve after a long trial of conservative interventions [29]. As some cases take longer than 9 months to improve and there is a high recurrence rate, surgery may also be considered if there is a desire for earlier return to sport or if femoroacetabular impingement coexists [31].

6.3.10 Pubic Ramus Stress Fractures

Stress fractures are common in athletes and military personnel . Pubic ramus stress fractures account for a small percentage of the stress fractures and are considered to be a low risk stress fracture. The etiology of pubic ramus stress fractures has not been fully elucidated, but one common thought is that it often starts with a periosteal reaction at the adductor muscle origin on the pubis as a result of the tensile forces. In general, risk factors for stress fractures include female sex, amenorrhea, smoking, poor nutrition, valgus knee alignment, and leg length discrepancy [32]. Stress fractures are usually seen in distance runners with recent increases in distance or speed as well as in military personnel who enter basic combat training with poorer indices of physical fitness [33].

The differential diagnosis includes femoral neck stress fracture, osteitis pubis, pubic symphysis dysfunction, athletic pubalgia, inguinal hernia, adductor tendinopathy, or referred pain from the genitals or pelvic organs.

Athletes complain of an insidious onset of groin pain that is exacerbated by weight bearing and relieved by rest. It may be localized to the inguinal, peroneal, or adductor regions [34]. Physical examination reveals tenderness of the inferior aspect of the pubic rim, an antalgic gait, and a positive standing sign (frank pain or inability to stand unsupported on the affected leg). Plain radiographs may not be positive for several weeks after the initial injury but are still the preferred initial study due to cost and availability [33]. If the plain radiograph is negative and a stress fracture is still suspected, then advanced imaging with MRI is indicated [32].

Treatment consists of avoiding pain-inducing activities for 4–6 weeks. The athlete should focus on non-weight-bearing activities and stretching of the adductor muscle group and hip joint capsule. This is followed by a gradual functional progression to activity. Most athletes will show a response to treatment in 3–5 months. In addition, evaluation of the athlete’s nutritional intake, estrogen status, and training program is warranted.

6.3.11 Femoral Neck Stress Fractures

Femoral neck stress fractures account for approximately 10 % of stress fractures, but these injuries can be a potentially career-ending with complications that include avascular necrosis, nonunion, and varus deformity [33]. As such, the clinician needs to maintain a high index of suspicion for this injury. Femoral neck stress fractures are classified as tension or compression, with tension side fractures much more likely to become a displaced fracture, but with compression side stress injuries being more common. Like pubic ramus stress fractures, stress fracture of the femoral neck often occur in distance runners and is usually preceded by a recent change in mileage or intensity. Both intrinsic characteristics of an individual's body and extrinsic factors can precipitate a stress injury. Risk factors include training errors, inadequate footwear, inadequate nutrition, amenorrhea, running on poor surfaces, coxa vara, and femoroacetabular impingement [32, 35, 36].

The differential diagnosis includes avascular necrosis, transient osteoporosis, hip flexor tendonitis or bursitis, hernia, osteitis pubis, and neoplasm [37].

The athlete may describe an aching in the groin, hip, thigh, or knee, which abates shortly after cessation of activity. Nocturnal pain is also common. Pain is associated with exertion and weight-bearing. The athlete often notes a progressive limitation of activity because of the pain.

On physical examination , the athlete may have a positive log roll, a positive FABER test, and the Stinchfield test will cause groin pain [24]. There may also be pain with axial compression and pain with percussion over the greater trochanter. A walking evaluation may reveal an antalgic gait or painful Trendelenburg gait. The single leg hop test will likely be positive, but many feel the hop test should not be performed in patients suspected of having a femoral neck stress fracture for fear of completing the fracture.

If a femoral neck stress fracture is suspected and physical exam findings are suggestive, then it should be considered to be present until proven otherwise. Distinct radiographic findings may not develop until weeks after the initial injury (Fig. 6.6). MRI is used to localize the injury and grade its severity [38]. Additionally, studies have found MRI for the diagnosis of femoral stress fracture to be both 100 % sensitive and specific [39, 40].

Fig. 6.6

An anteroposterior view of the pelvis in a patient with prior history of femoral neck stress fracture demonstrating old callus along the compression side of the right femoral neck

The primary goal in management of femoral neck stress fractures should be to prevent complications through early diagnosis and careful treatment. If a stress fracture is suspected, the athlete should remain non-weight-bearing on the affected leg until a full evaluation for a stress injury is completed. Return to play following a stress fracture can take as long as 4–5 months.

Tension side stress fractures , also known as distraction fractures , are more common in older patients and occur on the superolateral side of the femoral neck. These should be referred immediately to an orthopedic surgeon as the preferred treatment is surgical fixation of the fracture.

Compression side stress fractures are more common in younger patients and occur on the inferomedial side of the femoral neck. Compression side femoral neck stress fractures involving more than 50 % of the width of the femoral neck should be referred to an orthopedic surgeon for consideration of operative management. If the fracture involves less than 50 % of the width of the femoral neck, there is low risk for displacement, and it can be treated with prolonged non-weight-bearing until pain-free. Some patients require a short time on bed rest. The athlete should not bear weight until there is evidence of radiographic healing. Frequent radiographs should be performed until complete healing is documented. Supervised gradual return to activity can then occur. Recurrence of pain requires rest for 2–3 days, and then resumption of activity at the last tolerated level of activity. Progression of the fracture and other failures of nonoperative management are indications for immediate orthopedic surgical referral.

A displaced fracture is a combination of both tension and compression fractures, which results in displacement of the femoral head. This type of femoral neck stress fracture is an orthopedic emergency requiring immediate surgical reduction and internal fixation. Exact time lines for return to activity depend upon the nature of the fracture, type of fixation utilized, and surgeon’ s preference.

6.3.12 Hip Dislocation

A trauma with high energy directed along the axis of the femur when the hip is in the extremes of its normal range of motion is required to cause a hip dislocation. Hip dislocations can be anterior, posterior, or central. Posterior dislocations account for 90 % and anterior dislocations account for much of the remainder [41, 42]. The clinician must maintain a high index of suspicion for associated injuries including fractures of the femoral neck, femoral head, and acetabulum.

When a hip dislocation occurs, the athlete is immediately disabled and complains of extreme pain. Attempts to move the hip will increase discomfort. Posteriorly dislocated hips are characteristically held in adduction, internal rotation, and slight flexion. The femoral head may be palpable posteriorly.

A hip trauma series of plain radiographs should be obtained in the emergency room . CT scans are not routinely obtained prior to reduction because of the need for rapid treatment but are usually obtained after the reduction.

Hip dislocations are orthopedic emergencies . Attempts at reduction should not be performed on the playing field. However, it is critical to perform an on-field neurovascular examination, because sciatic nerve injury is observed in 10–14 % of patients with posterior dislocations. The athlete should be immobilized and transported to the emergency room for definitive evaluation and treatment [42, 43]. Prompt reduction using proper technique is important in decreasing the incidence of avascular necrosis of the femoral head, sciatic nerve injury, degenerative joint disease, and chondrolysis. The blood supply to the femoral head reaches a minimum level after 24 h after injury, and reduction after 24 h has been shown to cause an increase in osteonecrosis and post-traumatic arthritis. A reduction within 6 h enhances early recovery of the vascularity to the femoral head [44].

6.3.13 Avascular Necrosis of the Femoral Head

Avascular necrosis of the femoral head (AVN) is a cause of pain and loss of function. The pathophysiology of this disease is poorly understood, but it involves thrombus formation in the microvasculature of the bone followed by endothelial cell dysfunction and a disruption of normal angiogenesis [45]. There are both traumatic and atraumatic causes of AVN. Traumatic causes include displaced fractures of the femoral neck and hip dislocation. Atraumatic causes are not as well defined but include systemic corticosteroid use and heavy alcohol intake [46]. The majority of cases of AVN will be diagnosed in persons between the ages of 30 and 60 years and will be males [47].

The differential diagnosis includes osteoarthritis, iliopsoas bursitis, femoroacetabular impingement, and femoroacetabular labral tears.

Athletes usually present with nonspecific groin or hip pain that is worse with weight-bearing and nonspecific hip motion. Pain at rest and night pain also occur. On physical examination, hip range of motion and gait are usually normal except in advanced disease. Plain radiographs of both hips are essential in making the diagnosis. Osteopenia or a mottled appearance with patchy areas of sclerosis and lucency of the femoral head are the earliest radiographic findings but may not be present until 3 months after the inciting injury. As the disease progresses, there is collapse of the involved segment and degenerative change. If AVN is suspected and radiographs are normal, MRI can be used to make the diagnosis and to stage severity. The use of gadolinium increases the likelihood of detection early in the course of the disease.

Management depends on the stage of the disease and should be coordinated with an orthopedic surgeon. Goals of treatment include pain control and improved function. Bone marrow transplants have shown promise in the treatment of AVN [48], but core decompression a nd arthroplasty are the mainstays of treatment .

6.3.14 Osteoarthritis

Osteoarthritis of the hip is the end stage of many different disorders and the prevalence is on the rise as the population ages. It is the main cause of anterior hip pain in patients over 50 years of age [49]. Patients will complain of hip and groin pain with weight bearing that is relieved by rest. Plain films are helpful in confirming the diagnosis and will show joint degeneration. The disease process is irreversible and the mainstays of treatment are analgesia and surgery. For a more complete discussion of osteoarthritis, see Chap. 14.

6.3.15 Acetabular Labral Tear

Like the shoulder, the hip has a labrum consisting of a fibrocartilaginous rim that serves to deepen the acetabulum. Acetabular labral injuries typically present after an athlete has experienced some form of trauma such as slipping, twisting, or dislocation, and the most common tear location is in the anterosuperior region of the labrum [50]. Labral tears have been identified as precursors of osteoarthritis, and recognition and correction may mitigate progression of hip osteoarthritis [51]. Labral tears are also commonly associated with femoroacetabular impingement which is the next topic in this chapter.

The differential diagnosis includes extra-articular causes of internal snapping hip, iliopsoas tendinosis, iliopsoas bursitis, AVN, and synovial chondromatosis.

The classic symptoms of a labral injury include painful catching or clicking of the hip. The athlete may also experience episodes of sharp groin pain precipitated by pivoting or twisting, and a feeling that the hip is “giving way.” Physical examination reveals palpable clicking on Thomas flexion-to-extension, which frequently correlates with the finding of labral tears at arthroscopy [52]. Assessment for anterior labral tears includes moving the hip from full flexion with external rotation and abduction into extension with internal rotation and adduction with reproduction of the patient’s symptoms as a suggestive finding. Moreover, in the assessment of posterior labral tears bringing the hip from full flexion with adduction and internal rotation into extension with abduction and external rotation may reproduce the patient’s symptoms.

Plain radiographs are the initial study of choice in the evaluation of intra-articular disease due to low cost and high availability. MRI will help in the assessment of soft tissue derangements, but is limited in its ability to detect chondral and labral lesions. Magnetic resonance arthrography (MRA) or hip arthroscopy are the diagnostic investigations of choice in acetabular labral tears [53]. However, there is a high rate of asymptomatic labral tears in young and active individuals [54]. For this reason, the clinical relevance of labral tears on advanced imaging should be supported by history, physical examination, and the use of local anesthetic. Injection of local anesthetic into the joint guided by fluoroscopy or ultrasonography can be useful in diagnosing symptomatic labral tears. If symptoms resolve after injection, an intra-articular etiology is more likely [55].

Conservative intervention with analgesics, guided corticosteroid injection, and/or physical therapy may be tried. Protected weight-bearing for 4 weeks may result in symptom resolution in a limited number of cases [55]. If conservative measures fail, surgical intervention by hip arthroscopy should be offered and is also the preferred method of treatment by many experts [56].

6.3.16 Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is caused by the abutment of the anterior femoral head–neck junction against the adjacent anterosuperior labrum. Recognition of FAI can be clinically and radiographically difficult. However, familiarity with this disorder is essential as it is thought to progress to osteoarthritis in young adults [57, 58]. CAM-type FAI is commonly found in young athletic males, and is described as an abnormal femoral head–neck junction [59]. Pincer-type FAI is commonly found in middle-aged women, and is described as an over-coverage of the femoral head by the acetabular wall [59]. Mixed-type FAI has also been described.

The differential diagnosis includes hip dysplasia, greater trochanteric pain syndrome, iliopsoas tendinopathy, iliopsoas bursitis, athletic pubalgia, quadriceps strains, osteoarthritis, and hamstring tendinopathy.

Patients present with groin pain, loss of function, restricted hip range of motion, as well as grinding or popping [60]. Pain is associated with flexion and internal rotation and will occur after prolonged sitting. In general, physical examination maneuvers on patients with FAI pathology are of high sensitivity, poor specificity, and are limited in their ability to aid in the diagnosis [61]. There may be a decrease in internal rotation of the hip that is associated with pain, and the FADIR (flexion, adduction, internal rotation) impingement test may be positive. A positive painful squat test increases the probability of FAI as the correct diagnosis [62].

Initial radiographs are helpful in identifying morphological cam and pincer deformities and to exclude other possible diagnoses (Fig. 6.7). The findings of a pistol-grip deformity and an abnormal alpha angle are suggestive of cam-type FAI, and a cross-over sign and significant acetabular retroversion are suggestive of pincer-type FAI [24]. MRA is then used to determine the degree of chondrolabral damage [60]. However, asymptomatic cam and pincer deformities are fairly common. As such, the diagnosis of FAI remains a clinical diagnosis that is aided by imaging [60, 63].

Fig. 6.7

Radiographic features of femoroacetabular impingement. This anteroposterior view of the pelvis demonstrates bilateral pistol-grip deformities consistent with Cam lesions (arrows) as well as acetabular over-coverage consistent with pincer lesions (stars). The left hip also has os acetabuli just distal to the pincer lesion

Athletes with mild and non-limiting symptoms can be managed with activity modification and close monitoring. Many athletes will experience persistent pain and limited range of motion for which surgical intervention is indicated. Advances have allowed for arthroscopic-based treatment with faster rehabilitation and less restrictions [59]. The goals of treatment include pain reduction, increasing range of motion and function, and preventing further degeneration of the femoroacetabula r joint.

6.3.17 Athletic Pubalgia

Athletic pubalgia is a controversial overuse injury that goes by many different names including hockey player’s syndrome, Gilmore’s groin, slap shot gut, the sportsman’s hernia, and inguinal disruption. Use of the word “hernia” for this syndrome is common but is a misnomer as the pathology rarely involves herniation of tissues. This injury is more common in men than women and typically occurs in fast-moving sports that involve twisting, turning, and kicking. This injury is common in hockey, soccer, football, baseball, and rugby. The involved pathology involves weakness to the posterior wall of the inguinal canal, external ring dilatation, conjoined tendon damage, and tears in the inguinal ligament [64].

The differential diagnosis includes adductor strains, osteitis pubis, degenerative hip disease, inguinal or femoral hernias, FAI, or referred genital or rectal pain.

Athletes present with an insidious onset of unilateral “deep” groin pain exacerbated by exercise and relieved by rest. In chronic cases, the athlete may have pain with activities of daily living. Sudden movements, sit-ups, and increases in intra-abdominal pressure may also worsen the pain.

Athletic pubalgia presents a diagnostic challenge as there is no clear consensus on this clinical entity. Examination usually reveals pain over the conjoined tendon, pubic tubercle, and the deep and superficial inguinal rings. Pain may be reproduced with a resisted sit-up, and there may be observed adductor and hip flexor weakness with dynamic movement [65]. Radiographs may assist to rule out other injuries. A dedicated MRI protocol is the study of choice for athletes with this suspected cause of groin pain, with the protocol detailed to 1.5 T or 3 T systems, coil selection and positioning, and specific sequencing [66, 67]. Diagnostic anesthetic injections of the femoroacetabular joint and the pubic symphysis may aid in the evaluation by ruling out other causes of pain [68].

The goal of treatment is pain reduction and return to sport. Initially, nonoperative treatment with rest, oral analgesics, and physical therapy should be considered. After an initial period of rest, there is a slow resumption of physical activity with supervised physical therapy consisting of core stabilization, pelvic stabilization, strengthening, and flexibility training. Multiple rehabilitative programs have been described [69]. Those who insist on continuing activity will take considerably longer to heal. Athletes who fail conservative treatment should be referred to a surgeon familiar with this disorder for evaluation [70, 71].

6.3.18 Internal Snapping Hip

Snapping hip syndrome , also known as coxa saltans, is a clinical condition with a painful, audible snap occurring during hip flexion or extension. Snapping hip is more common in females and most commonly seen in individuals in their late teens and twenties who are active in dance and running [72]. There is usually no history of trauma.

Internal snapping hip is subdivided into intra-articular and extra-articular causes. Extra-articular internal snapping is typically caused by the iliopsoas tendon snapping across the head of the femur, catching on the iliopectineal eminence, or impingement on an overhanging acetabulum [73]. Intra-articular internal snapping hip is most often caused by loose bodies that may arise from labral disease, acetabular or femoral head chondral lesions, idiopathic recurrent hip subluxation, and synovial chondromatosis [74].

The differential diagnosis for internal snapping hip includes external snapping hip, AVN, and athletic pubalgia.

In extra-articular internal snapping hip, the athlete will report an audible and sometimes painful snap with motion of the hip. Athletes are usually able to reproduce the snap with certain hip motions. The snap is felt in the groin or anterior hip. Pain associated with internal snapping hip is insidious in onset. Performance is rarely impaired. In intra-articular internal snapping hip, athletes report a sudden onset of snapping or clicking after trauma. Reproduction of the snap is more difficult, and performance may or may not be inhibited.

The diagnosis of internal snapping hip is made clinically, and a detailed examination is important. The physical examination is performed by placing the athlete in a supine position with the hip flexed, externally rotated, and abducted. The hip is then passively extended, internally rotated, and adducted to reveal snapping as the iliopsoas tendon passes over the femoral head and joint capsule. In extra-articular internal snapping hip, snapping may be prevented by placing significant pressure on the iliopsoas tendon and anterior hip [74–76]. Intra-articular snapping may be uncovered with a scour test.

Plain radiographs are often normal in athletes with snapping hip. However, they are imperative to exclude less common etiologies such as fractures, loose bodie s, dysplasia, and synovial chondromatosis. Historically, bursography and tenography have also been used to diagnose snapping hip [74]. However, static and dynamic musculoskeletal ultrasonography have become readily available and can aid in the diagnosis. Static ultrasonography will demonstrate iliopsoas tendon thickening, enlarged bursa, and peritendinous fluid collections. Dynamic ultrasonography will show the moving structures of the hip and reveals an abnormal jerking motion of the iliopsoas tendon corresponding to the athlete’s location of pain and audible snapping [77–79]. MRA may be used to evaluate for intra-articular causes of internal snapping hip including labral tears, osteochondral fractures, and loose bodies. In extra-articular snapping, the MRI may show iliopsoas tendon thickening and inflammation of the iliopsoas bursa.

The mainstay of treatment for extra-articular internal snapping hip is nonoperative and involves rest, activity modification, NSAIDs, and physical therapy. Hip flexor stretching and strengthening, pelvic mobilization, and alignment exercises help relieve the pain of internal snapping hip. Core stabilization and pelvic tilt should also be addressed. Other interventions include corticosteroid injection of the bursa and biofeedback to teach the patient how to avoid repetitive hip snapping. If conservative therapy does not adequately relieve symptoms, then referral for surgical management is indicated.

6.4 Lateral Hip and Pelvis Pain

6.4.1 External Snapping Hip

As with internal snapping hip, external snapping hip is also commonly seen in runners and dancers and in the second and third decades of life. External snapping hip is more common than internal snapping hip. It is caused by friction on the greater trochanter of the femur by the iliotibial band (ITB), the anterior border of the gluteus maximus, or the posterior border of the tensor fascia lata (TFL). The ITB is thought to be the most common cause. Ordinarily, the ITB glides smoothly over the greater trochanter with assistance from the underlying bursa. If the posterior aspect of the ITB band is thickened, it will then rub over the greater trochanter and cause a snapping sensation. The bursa may also become painful and inflamed. Other proposed causes of external snapping hip relate to alterations in hip mechanics including decreased angulation of the femoral neck (coxa vara), narrow biiliac width, increased distance between the greater trochanters, and prominent greater trochanters [74, 80, 81].

The differential diagnosis includes internal snapping hip, AVN, acetabular labral tears and athletic pubalgia.

Athletes will report of an audible and often painful snap over the lateral hip with certain movements. The athlete can often voluntarily reproduce the snapping. Ober testing during physical examination will reveal snapping when the affected leg is taken from full extension to 90° of flexion. The examiner’s hands should be placed posterior to the greater trochanter in order to feel the snap. If enough force is applied to the greater trochanter to keep the ITB reduced posteriorly, the snapping will not occur with maneuvers.

If the diagnosis is unclear after the history and physical examination, then imaging may be warranted. Plain radiographs are typically normal. Musculoskeletal ultrasonography has been used in external snapping hip to visualize the ITB or gluteus maximus muscle snapping over the greater trochanter [74]. MRI is generally not needed but may show inflammation of the greater trochanteric bursa or thickening of the ITB or gluteus maximus.

The mainstay of treatment for external snapping hip is nonoperative and involves rest, activity modification, NSAIDs, and physical therapy. Physical therapy should include stretching of the ITB, core stabilization, and correction of functional pelvic tilt. Corticosteroid injection of the greater trochanteric bursa can be performed if these measures are unsuccessful or if severe pain limits the athlete’s participation in rehabilitation. If conservative interventions do not relieve symptoms, then referral to orthopedic surgery may be considered.

6.4.2 Greater Trochanteric Pain Syndrome

The diagnosis of “greater trochanteric bursitis” has been debated as imaging and surgical pathology often fails to reveal increased bursal fluid and evidence of inflammation. As such, experts are referring to this clinical entity as greater trochanteric pain syndrome (GTPS). This umbrella term can be applied to the involved pathologies of trochanteric bursitis, gluteus medius and minimus tendinopathy and tears, ITB disorders, and TFL disorders [82]. The previously described external snapping hip is on the spectrum of these disorders. Disorders of the gluteus medius and minimus are further discussed later in this chapter in the section on posterior hip and pelvis pain. GTPS is more common in women and is often found in association with or preceded by low back pain [83]. In runners, it is commonly a result of overuse rather than direct trauma, and risk factors include a broad pelvis, leg length discrepancy, and excessive pronation of the foot [84].

The differential diagnosis includes pain radiation from the sacroiliac joint, radicular symptoms of lumbar origin, and piriformis syndrome.

Athletes will report lateral hip pain that may radiate into the buttock or down the lateral aspect of the thigh. They may complain of pain with prolonged standing, lying on the ipsilateral side, climbing stairs, or running. On physical examination, there will be point tenderness over the greater trochanter, the lateral aspect of the hip, and the posterior hip along the gluteus medius and minimus muscles. Pain may be exacerbated by external rotation and abduction of the hip. Clinicians will often find the hip abductors to be weak, the ITB to be tight, and Patrick’s test (FABER) causes lateral hip pain.

The diagnosis is made clinically, and imaging is generally unnecessary. Plain radiographs may reveal irregularities of the greater trochanter and tendon calcifications [85]. MRI may show peritrochanteric edema, gluteus medius and minimus tendinosis or tear, and bursal fluid [85]. Similarly, ultrasonography may show tendinopathy or tendon tears, increased bursal fluid, and evidence of enthesopathy [77, 85, 86].

This syndrome is highly responsive to conservative interventions. Initial treatment should begin with ice massage, heat contrasts, and oral analgesics. A rehabilitative program should include TFL and ITB flexibility and mobilization as well as gluteal, hip abductor, and core strengthening exercises. Local anesthetic and corticosteroid injection may be helpful for severe pain or if pain is refractory to other treatment modalities. Other options for refractory cases include extracorporeal shock wave therapy, percutaneous needle tenotomy, platelet-rich plasma or whole blood injection, prolotherapy, and surgical intervention [85]. Leg length and other biomechanical discrepancies should be corrected to prevent recurrence [80].

6.4.3 Iliac Crest Contusion

Iliac crest contusions typically occur in contact sports from a direct trauma to an unprotected iliac crest. This trauma may cause a contusion, hematoma formation, or muscle avulsion. The term “hip pointer” is used to describe an iliac crest contusion that is associated with a subperiosteal hematoma [46, 80].

The differential diagnosis includes fractures of the ilium and avulsions of the nearby soft tissues.

Athletes complain of pain over the iliac crest with ambulation, rotation, and bending at the waist away from the injured side. The athlete may also report numbness or decreased sensation in the lateral buttock and hip if there is damage to the lateral femoral cutaneous nerve, iliohypogastric nerve, or ilioinguinal nerve.

Physical examination may reveal swelling, ecchymosis, and tenderness over the iliac crest extending superiorly into the internal and external oblique muscles. A hematoma may be palpable and a palpable defect along the iliac crest would indicate an avulsion injury. Radiographs are generally unnecessary at the time of diagnosis, but pelvic radiographs are indicated to evaluate for fractures and periostitis in athletes with prolonged or severe symptoms. Ultrasonography is useful in visualizing the subperiosteal hematoma, may demonstrate muscle disruption, and can assist with hematoma aspiration [24] (Fig. 6.8).

Fig. 6.8

Ultrasound image over the iliac crest demonstrating muscle fiber discontinuity following iliac crest contusion (outlined in yellow). LT left

Treatmen t is initiated immediately with ice and compression to minimize swelling and hematoma formation. Rest, activity modification, and oral analgesia may be recommended depending on the severity of symptoms. Abdominal muscle, low back, and flank stretching and strengthening are performed as tolerated. Treatment with local anesthetic and corticosteroid injection is generally considered safe and effective and may aid in earlier return to play [87]. However, prior to resumption of contact sports, trunk range of motion should be pain-free and the athlete should be protected with adequate padding.

6.4.4 Meralgia Paresthetica

Meralgia paresthetica is a mononeuropathy caused by compression of the lateral femoral cutaneous nerve [88]. The most common site of entrapment is at the inguinal ligament. Meralgia paresthetica is more common in males than females and is associated with the sports of gymnastics, baseball, soccer, and body building [89]. It is also commonly found in diabetics, the obese, older patients, and in people who wear tight pants, belts, or girdles [84].

The differential diagnosis includes lumbar radiculopathy and greater trochanteric pain syndrome.

Most athletes will describe pain, numbness, tingling, or burning pain over the anterolateral thigh. The athlete should be questioned about important predisposing factors such as recent weight gain or previous surgical procedure. In athletes, prolonged flexion (marksmen), increased muscle mass (weight lifters), or constrictive clothing may play a role. However, in the athletic population, it is not unusual for no identifiable cause to be found [84].

The diagnosis is made clinically and is based on sensory symptoms in the lateral femoral cutaneous nerve distribution. On physical examination, a positive Tinel’s sign is usually present one centimeter inferomedial to the anterior superior iliac crest. The pelvic compression test is a useful and simple clinical test to support the diagnosis of meralgia paresthetica [88]. Nerve block testing may aid in the diagnosis and is considered positive if an anesthetic injected at the site where the lateral femoral cutaneous nerve passes the inguinal ligament causes immediate relief of symptoms [89]. Electrophysiologic testing is technically difficult but may demonstrate prolonged latency or decreased conduction velocity consistent with compression [46, 90]. Radiographs and MRI of the hip and pelvis are useful if there is concern for intra-pelvic and intra-articular compression on the nerve.

Heat, compression avoidance, physical therapy, and NSAIDs have been shown to be effective in the treatment of meralgia paresthetica. Nerve blocks and radiofrequency ablations are also considered effective [91, 92]. However, high quality evidence is lacking to support these interventions. If symptoms are persistent and disabling despite conservative therapy, then surgical intervention may be warranted.

6.5 Posterior Hip and Pelvic Pain

6.5.1 Hamstring Strain

The hamstring is made up of the semitendinosus, semimembranosus, and the long and short heads of the biceps femoris . The three muscles have a common origin at the ischial tuberosity. The hamstring is highly susceptible to injury because the muscle group spans two joints. Hamstring injuries may be the most common injury in sport [93]. Of the muscles in the hamstring, the biceps femoris is the most frequently strained. Complete tears are rare, but have been reported in water skiers, runners, dancers, and power lifters. The most important risk factor for a hamstring strain is a history of a prior hamstring strain [93]. Other risk factors for hamstring injuries include leg length discrepancy, muscle imbalances, insufficient pre-activity stretching, and poor technique [94].

The differential diagnosis includes radicular pain of lumbar origin, referred pain from the SI joint, and avulsion fracture of the ischial tuberosity.

Athletes usually self-diagnose the injury at the time that it occurs. Patients will describe acute onset posterior thigh pain and maybe even a “pop” at the time of injury [95].

Physical examination may show edema and ecchymosis over the affected muscle belly. The examiner should palpate the ischial tuberosity and follow the muscle inferiorly to locate the area of maximal tenderness, size of the area of tenderness, and to determine whether there is a palpable defect in the muscle [95]. If the ischial tuberosity is extremely tender, then an avulsion fracture should be suspected. Pain is exacerbated with resisted knee flexion, and the athlete is often unable to fully straighten his or her knee due to pain.

The diagnosis of a hamstring strain is made by history and physical examination, and imaging is not routinely needed. Plain radiographs should be ordered in athletes with suspected ischial tuberosity avulsion fractures. Musculoskeletal ultrasonography and MRI may be used to assess the severity of injury. MRI is better able to detect small muscular injuries, however ultrasound has the advantage of providing assessment of the muscle dynamically [96]. Either ultrasonography or MRI should be used to confirm if a complete tear of the hamstring is suspected.

Like other soft tissue injuries, initial treatment should consist of ice, oral analgesia, compression wraps, and protected weight-bearing. This is then followed by passive hamstring stretches in the pain-free range. As the symptoms resolve, the athlete progresses to active hip and knee range of motion exercise, then on to hamstring strengthening and isometrics. Early studies showed promise in the treatment of hamstring injuries but there is currently no high grade evidence to support the use of platelet-rich plasma or stem cell therapy for hamstring strains [97, 98]. A complete avulsion of the entire hamstring group from the ischial tuberosity should be referred for possible surgical intervention [99].

6.5.2 Ischial Bursitis

Ischial bursitis, also known as weaver’s bottom, occurs after a contusion of the ischial tuberosity, as a complication after injury of the hamstring origin, or from prolonged sitting. The differential diagnosis includes hamstring strain, radicular pain of lumbar origin, referred pain from the SI joint, and avulsion fracture of the ischial tuberosity. Athletes will complain of pain while sitting [100].

On physical examination there will be localized tenderness over the ischial tuberosity. Ultrasound or MRI can be used to confirm the diagnosis [23] (Fig. 6.9). Treatment consists of rest, ice, oral analgesia, hamstring stretching and strengthening, and protection. A doughnut cushion will help alleviate pain while sitting. In recalcitrant cases, aspiration of the bursa and injection of corticosteroid should be considered.

Fig. 6.9

Ischial bursitis : A long axis ultrasound view of the semimembranosus tendon origin (semim—outline in blue) at the level of the ischial tuberosity (IT—outlined in red). The ischial bursa was found to be enlarged due to bursal effusion (outlined in green)

6.5.3 Gluteus Maximus Strain

The gluteus maximus is an extensor of the hip and trunk. Compared to hamstring injuries, isolated strains of the gluteus maximus are uncommon but can occur in sprinters. More often, this muscle is injured through direct trauma [101].

The differential diagnosis includes hamstring injury, ischial bursitis, radicular pain of lumbar origin, and referred pain from the SI joint.

The athlete will report a sharp pain in the buttock with sudden onset, typically during a burst of speed or sudden change in direction. On physical examination, the hip, lumbar spine, and SI joints should be examined. If no tenderness is elicited in any of these areas, then a gluteus maximus strain is suspected.

As this disease process is on the spectrum of GTPS, intervention and rehabilitation are essentially the same. Treatment of a gluteus maximus strain involves rest, ice, and compression. A rehabilitative program should be started with mobilization and range of motion and progresses to strengthening as the athlete tolerates. Return to full participation can occur once the athlete is pain-free and is able to do sports-specific activities.

6.5.4 Gluteus Medius Strain

The gluteus medius functions as a hip abductor. Injuries to this muscle are common in runners. The differential diagnosis includes hamstring injury, radicular pain of lumbar origin, and referred pain from the SI joint. The athlete will often complain of lateral thigh pain near the greater trochanter. There will be pain with palpation just proximal to the tendinous insertion on the greater trochanter and often in the muscle belly itself [102]. Resisted abduction of the hip will provoke pain. Treatment follows the same principles as GTPS with additional emphasis placed upon core strengthening [80].

6.5.5 Sacroiliac Joint Dysfunction

The SI articulation is formed by the sacrum and the ilia, and the major supporting ligaments include the anterior and posterior SI ligaments, the interosseous SI ligament, and the sacrotuberous ligament. Although uncommon, painful tearing and stretching of any of these ligaments can occur. Sports that involve repetitive unidirectional pelvic shear and torsional forces (skating, gymnastics, bowling) put the athlete at risk of SI joint dysfunction [103]. SI joint pain is also well described in rowers [104]. Loss of motion in the SI joint or sustained contraction of the overlying muscles may cause pain.

The differential diagnosis includes radicular pain, piriformis syndrome, gluteus medius strain, ankylosing spondylitis, Reiter’s syndrome, and other spondyloarthropathies. The clinician should have high suspicion for an autoimmune etiology if both SI joints are involved or if the athlete is not responding to conservative interventions.

The athlete typically presents with pain at one SI joint. The pain may radiate to the low back, groin, posterolateral hip, and thigh. The pain pattern may mimic radicular pain from a herniated nucleus pulposus or spinal stenosis.

During examination , care should be taken to ensure that features of ankylosing spondylitis, Reiter’s syndrome, and other spondyloarthropathies are not present. There will be unilateral tenderness over the affected posterior superior iliac spine and along the sacral sulcus. The lack of nerve root tension signs and absence of motor, reflex, or sensory deficits help distinguish SI joint dysfunction from nerve root compression lesions. However, SI joint dysfunction can present in conjunction with spinal pathology [105]. FABER, piriformis, and Gaenslen’s tests may be positive. Straight leg raise may cause SI pain. Pain is also exacerbated by forward flexion of the trunk with knees extended. A positive one-legged stork test (Gillet test) indicates a lack of mobility on the affected side. Sacral compression medial to the posterior superior iliac spine often causes localized pain. The athlete should also be evaluated for a leg length discrepancy [104].

No gold standard clinical or diagnostic testing exists for the diagnosis of SI joint dysfunction [105]. Plain radiographs and CT imaging may aid in the diagnosis but also show degenerative changes in asymptomatic patients and incur high false positive rates. MRI is the imaging modality of choice in suspected sacroiliitis with negative plain films [106]. Sacroiliac joint injection with an anesthetic may aid in the diagnosis but remains controversial [105]. Such injections should be performed under ultrasound or fluoroscopic guidance.

The goal of treatment is pain reduction and restoration of normal movement. Treatment consists of ice, NSAIDs, ice massage, and heat. A corset, constricting elastic bandage, or SI belt may provide pain relief. The rehabilitation program should include pelvic stabilization exercises and exercises to stretch and strengthen the piriformis muscle. Osteopathic manipulation may assist in reestablishing a neutral pelvis and corticosteroid injections should be considered in recalcitrant pain [24].

6.5.6 Piriformis Syndrome

The piriformis muscle originates on the anterolateral aspect of the sacrum and inserts on the upper border of the greater trochanter of the femur. The piriformis is an external rotator of the hip. Piriformis syndrome is the occurrence of pain at the site of the piriformis muscle secondary to inflammation or spasm. The nearby sciatic nerve may become secondarily involved.

The differential diagnosis includes hip joint disease, SI joint dysfunction, nerve root irritation, spinal stenosis, GTPS, and lumbar herniated nucleus pulposus.

Athletes usually present with a history of blunt trauma to the gluteal or SI region. They complain of pain in the lower SI joint, the greater sciatic notch, and piriformis muscle. The pain may radiate down the posterior buttock into the hip and thigh and is frequently exacerbated by stooping or lifting.

On physical examination , there is typically tenderness over the piriformis muscle. The Lasègue sign will demonstrate tenderness at the gluteal region around the piriformis muscle [107]. Buttock pain is exacerbated by hip flexion and passive internal rotation. Resisted hip external rotation exacerbates the pain. Straight leg raise is occasionally positive with referred pain down the posterior thigh and calf. Patients will often have a positive Gaenslen’s test. The FAIR test (flexion, adduction, internal rotation) has been shown to have a sensitivity of 88 % and a specificity of 83 % [108]. Radiographs, MRI, and CT scanning are not needed to make the diagnosis, but may show changes in the piriformis muscle or sciatic nerve [109].

Treatment of piriformis syndrome includes ice massage, NSAIDs, muscle relaxants, ultrasound, electrical stimulation, and physical therapy [103, 110]. Osteopathic manipulative treatment has also been shown to be helpful [111]. Local anesthetic or steroid injections may provide pain relief [112]. Injection of botulinum toxin has been shown to reduce buttock pain and improve hip functionality and quality of life in patients suffering with chronic piriformis syndrome [113]. To prevent recurrence, lumbosacral dysfunction and imbalances in the surrounding musculature must be concurrently treated. If conservative therapy fails or if the patient develops foot drop or gluteal muscle atrophy, then operative treatments are available [103, 110].

6.5.7 Coccygeal Injury

The coccyx is joined to the sacrum by cartilage which forms a synchondrosis . It is susceptible to injury during a fall on the buttocks, when struck from behind, or during a difficult vaginal delivery.

The differential diagnosis is limited in this region but examiners should consider referred pain from the spine or hip, intra-pelvic etiologies of pain, and pilonidal cysts.

Athletes will typically report direct trauma to the upper buttock. Insidious onset of chronic coccygeal pain may also be reported.

Physical examination reveals localized tenderness in the coccygeal region, localized swelling or ecchymosis, and pain exacerbated by sitting. If there is no history of trauma, rectal examination and lower abdominal evaluation are indicated. Plain radiographs are required to rule out an inferior sacrum fracture and to determine whether the coccyx is dislocated or displaced. Ultrasound may demonstrate an inflamed over-riding bursa (Fig. 6.10).

Fig. 6.10

Adventitial bursa over-riding the coccyx. Very light transducer pressure was required to obtain this long axis image. The bursa measured 33 mm by 1 mm

In the event of an acutely dislocated or displaced coccyx, the examiner may reduce the displaced element by inserting a lubricated index finger into the rectum so that the palmar surface rests against the anterior aspect of the coccyx. He or she then palpates the posterior aspect of the coccyx externally, applies a gentle traction on the coccyx, and glides the coccyx into its normal position. If successful, pain relief is usually immediate. However, there is no conclusive evidence as to the efficacy of this approach.

Like other contusions or non-displaced fractures, acute coccygeal injuries are treated with rest and analgesia. Successful treatment of chronic coccydynia has been reported with pelvic relaxation exercises, pelvic floor strengthening, biofeedback, local corticosteroid injection, botulinum toxin injection, and coccygectomy [114–117].

6.6 Other Hip and Pelvic Pain

6.6.1 Leg Length Discrepancy

There are two types of leg length discrepancies: true and functional . In a true leg length discrepancy, the actual length of the two lower extremities is different when measured from the femoral heads to the plantar surfaces of the feet. This may be the result of a varus or valgus deformity of the femoral neck, congenital anomalies of the femur or tibia, or growth disturbances of the femur or tibia [118]. In a functional leg length discrepancy, the athlete’s two lower extremities are, in fact, the same length, but pelvic obliquity gives the appearance of a discrepancy. Possible causes of a functional leg discrepancy include contractures at the lumbosacral junction due to scoliosis, post-traumatic deformities of the pelvis, somatic dysfunction of the pelvis and SI joints, and muscle contractures about the hip and knee.

Pain originating in the pelvis, low back, and hip region can be caused or worsened by a disparity in leg length. The evaluation of atraumatic hip and pelvis pain should always include screening for a leg length discrepancy [118–120]. The physical examination and osteopathic manipulation chapters discuss the evaluation of leg length in greater detail.

A more precise measurement of leg length is obtained with a standing AP radiograph film of the pelvis down to the feet. This view should include the upper lumbar spine and the femoral heads. The athlete should stand with his or her feet shoulder width apart with equal weight distribution while the plain film is being taken. Lines are then drawn on the radiograph at the superior sacral ala bilaterally to form a sacral base and at the superior margin of each femoral head. The examiner then draws a line from the sacral base and femoral heads to the base of the film. This method is recommended if the standing measurements have not been accurate. Instead of plain radiographs, some facilities are now using a quick computer tomography scan from the upper lumbar spine to the feet and then comparing measurements from the medial malleolus to the superior margin of the femoral head on each side.

True limb length discrepancies are treated with orthotics and other assistive devices. Functional limb length discrepancies are treated with rehabilitation a nd manual medicine.

6.7 Conclusion of the Case

The patient was diagnosed with greater trochanteric pain and ITB syndromes. He was instructed to take a 7 day course of NSAIDs. He was referred to physical therapy for gluteus medius, quadriceps, hamstring, and ITB stretching and strengthening with modalities (ultrasound, electrical stimulation, iontophoresis, or phonophoresis) as needed to assist with pain control. A core stabilization program was also emphasized. Additionally, over-the-counter orthotics were recommended for the pes planus with hyperpronation. He responded well and was back to his usual activities in approximately 6 weeks.