Keywords

Epidemiology

  • Proximal humerus fractures are relatively rare and represent 4–5% of all fractures [1]:

    • The majority of proximal humerus fracture are not significantly displaced, and do not require surgery.

    • Can be associated with shoulder dislocation and rotator cuff tears.

  • Patient population: Trauma, young individuals with high-velocity mechanism of injury, such as MVC

    • Associated injuries: soft tissue destruction, injuries to thorax such as rib fractures and pnuemothorax, and distracting injuries to other extremities

  • Individuals >50 years of age with fall as mechanism of injury, osteoporotic bone

    • 4:1 Female to male ratio [11]

Anatomy

  • The humeral head is retroverted 30–45° [6, 14].

  • Deforming forces to the 4 osseous segments of the proximal head occur. Understanding the osseous segments and deforming forces is key to fracture classification and treatment.

    • 4 proximal humerus osseous segments:

      • Humeral head.

      • Lesser tuberosity (LT): attachment site of the subscapularis tendon; will displace medially.

      • Greater tuberosity (GT): attachment site of supraspinatus, infraspinatus, and teres minor; will displace superiorly and posteriorly.

      • Humeral shaft: attachment site of deltoid, proximal segment will displace medially; attachment site for pectoralis major; shaft will displace medially [4, 6, 9, 11].

    • Other osteology:

      • Anatomic neck (AN): area below humeral articular surface, above tuberosities

      • Surgical neck (SN): begins at metaphyseal flare below tuberosities [6, 14]

    • Neurovascular supply:

      • Vascular: rich vascular supply makes osteonecrosis secondary to fracture a rare complication

        • Anterior humeral circumflex artery: includes anterolateral ascending branch and terminal arcuate artery

          • Pearl: fractures of anatomic neck, “danger area” due to blood supply

        • Posterior humeral circumflex artery: runs in quadrangular space

          • May play a greater role in perfusion to humeral head than previously believed [1, 9, 14]

      • Neuro: Axillary nerve, more susceptible to injury with anterior dislocations

        • Course off posterior cord, anterior inferior to glenoid humeral joint, lies posterior to axillary artery, anterior to subscapularis muscle, then courses through quadrangular space with posterior humeral artery

          • Motor: deltoid and teres minor

          • Sensory: superficial lateral cutaneous nerve of arm [6, 9, 14]

Presentation and Evaluation

  • Presentation: Patient may present with arm held close, swelling, tenderness, ecchymosis, and decreased range of motion

  • Evaluation: a neurovascular exam is crucial, especially with respect to the axillary nerve:

    • Axillary nerve: motor may be unable to obtain secondary to pain, but sensation over lateral proximal arm and deltoid can be tested, Hornblower’s test.

    • Distal upper extremity neurovascular exam should also be obtained and documented.

  • Radiographs: 3 views

    • AP shoulder

    • Axillary

      • Velpeau and West point are alternative views if axillary unobtainable secondary to pain.

    • Scapular Y

    • CT scan: indicated for preoperative planning, fractures with significant intra-articular involvement, and fracture patterns where location of displaced tuberosity or humeral head is unclear on plain films [6, 4, 9, 11, 16]

Classification and Treatment

  • Several different classification schemes have been created, but the Neer classification is the most commonly and consistently used system.

  • Neer classification: based on humeral osseous segments, parts, and displacement (see Table 11.1)

    • Part: fragment with >1 cm displacement or 45° of angulation

      • One-part fractures are almost exclusively treated nonoperatively, whereas two-part and greater fractures generally have operative indications.

    • Valgus impacted: not in original Neer classification, four-part fracture, humeral articular surface impacted on shaft in valgus position [4, 6, 9, 11, 14, 16].

  • Fracture-dislocations: occur, anterior most common, attempt closed reduction although may not be possible

  • Nonoperative treatment

    • Closed reduction and sling immobilization 2–3 weeks (see section V.), surgeon preference for initiation of range or motion exercises.

    • Patient’s age, pre-injury shoulder function, bone quality, compliance, activity level, dominance, occupation, and associated injuries should all be taken into account [4, 6].

  • Operative treatment

    • CRPP (closed reduction percutaneous pinning)

    • ORIF plate fixation most common

      • locking screws options, possible fixation of rotator cuff with sutures through plate

      • IMN less commonly used

        • Deltopectoral approach (shoulder anterior)

          • Positioning: supine with bump under medial scapula

          • Internervous plane: deltoid muscle and pectoralis major (axially nerve, medial and lateral pectoral nerve, respectively)

          • Dangers:

            1. 1.

              Axillary nerve

            2. 2.

              Musculocutaneous nerve

            3. 3.

              Anterior circumflex artery

            4. 4.

              Cephalic vein

        • Deltoid splitting approach (shoulder lateral)

          • Positioning: supine with bump under ipsilateral scapula or “beach chair” with arm at edge of table

          • Internervous plane: no true plane, deltoid spilt

          • Dangers:

            1. 1.

              Axillary nerve [1, 4, 6, 9, 11]

        • Pearl: Axillary nerve runs 5–7 cm distal to tip of acromion [2].

Table 11.1 Neer classification of proximal humerus fractures
Full size table

  • Arthroplasty: Hemiarthroplasty vs. reverse shoulder arthroplasty

    • Indicated for older patients with poor bone quality, complex fractures involving articular surface, and humeral head split [1, 6, 16]

    • Nonunion

      • Pearl: Humeral height, the top of prosthesis head should sit 5.6 cm cephalad to tip of pectoralis major tendon insertion [12, 15].

Posttreatment Rehabilitation

  • Frequent x-rays assure no increase in displacement, proper bone healing, and hardware placement.

  • Sling or sling with abduction pillow.

  • Begin motion early, advance in phases, surgeon preference:

    • Pendulum swings

    • Passive range of motion exercises, especially wrist and elbow

    • Active range of motion at 4–6 weeks

    • Resistance work at 6–12 weeks

    • Full function normally within 1 year [4, 6, 9, 11, 16]

Complications

  • Axillary nerve injury

    • Initial injury: 5–30% complex fractures, especially with anterior fracture-dislocation [11]

    • Iatrogenic causes, lateral pin placement in CRPP [9]

  • Vascular injury

  • Osteonecrosis

  • Nonunion

    • Treat with revision ORIF with allograft versus autograft bonegrafting, arthroplasty in older patients [1, 3, 5, 16]. Treatment based on patient level of pain, function, overall health.

  • Malunion

    • Varus deformity in younger patient, treated with revision ORIF and osteotomy [13].

    • Greater tuberosity malunion treated with hemiarthroplasty [8].

  • Infection

    • Rare due to rich vascular supply

    • Pearl: Propionibacterium infections may occur more with hemiarthroplasty [16].

  • Adhesive capsulitis

  • Myositis ossificans

  • Stiffness and decreased range of motion

    • Secondary to prolonged immobilization

  • Intra-articular screw penetration

    • Most common complication with locking plate use [10]