Introduction

The integrity of rotator cuff repair has been shown to correlate with clinical outcomes, particularly return of strength [3, 14, 27]. Repair of the torn rotator cuff tendon can be performed by a variety of methods including open, mini-open, and arthroscopic techniques. Arthroscopic rotator cuff repair is becoming the gold standard because it is a less invasive technique and spares the deltoid muscle [20]. Despite the improvement in surgical techniques and postoperative protection of the repaired tendon, imaging techniques at follow-up show a high percentage of re-tear or nonhealing of tendons [3, 13]. Although some very important biological aspects related to rotator cuff repair should be better clarified, a potential technical limitation of the arthroscopic technique has been related to the use of suture anchors—particularly when used in a single-row fashion, which only partially is able to reproduce the bone–tendon footprint [1]. Furthermore, the use of anchors has been associated with different complications, such as anchor pull-out and greater tuberosity bone osteolysis [2]. Consequently, as arthroscopic rotator cuff repair techniques continue to evolve, the best all-arthroscopic method has not been established and open transosseous rotator cuff repair techniques still remain the gold standard for tendon healing [21]. Recent biomechanical studies demonstrate that arthroscopic techniques with anchors may mimic open repair, but as of today no replication of the open transosseous technique has been performed in an all-arthroscopic fashion [10]. In this paper, we describe a novel and reproducible technique that allows surgeons to replicate open transosseous rotator cuff repair in an all-arthroscopic fashion.

Technical note

The procedure is performed with the patient under general endotracheal anesthesia combined with an anterior interscalene cervical plexus block. The patient can be placed in a modified beach-chair position or in a lateral decubitus depending on surgeon preference. For optimal suture management, the authors suggest to use a 4 portal surgical technique: standard posterior and anterior superior portals, an anterolateral portal in line with the anterior edge of the supraspinatus tendon, and a posterolateral portal. Once the reparability of the rotator cuff is assessed, with the scope on the posterior or in the posterolateral portal, a specific drill guide is inserted through the anterior superior portal to create a 2.9-mm medial tunnel immediately adjacent to the articular surface (Fig. 1). At this point, through the anterolateral portal, we gently introduce a device that allows the creation of an intersecting tunnel (ArthroTunneler, Tornier, Edina, MN, USA) (Fig. 2). Once the position is satisfactory, the lateral intersecting 2.5-mm tunnel is drilled. The position of the lateral tunnel is approximately 1.5 cm below the superior tip of the greater tuberosity. At this point, a loaded suture inserter is introduced through the hole of the ArthtroTunneler device. The loop of the ArthroTunneler is moved into the retrieval position, and the suture inserter is removed leaving the suture passed in a transosseous fashion through the greater tuberosity (Fig. 3). The suture is retrieved by the device through the medial tunnel completing the transosseous suture passage. This suture is used as a shuttle to pass 2 or 3 definitive sutures through the tunnel (Fig. 4). All transosseous sutures are first placed in the bone and are then passed through the cuff with different devices according to surgeon preference (Figs. 5, 6). Depending on the tear size, one, two, three, or even four tunnels can be created to repair the tear; furthermore, different kinds of suture pattern can be created based on surgeon preference (Fig. 7).

Fig. 1
figure 1

a Arthroscopic view of a right shoulder. The scope is in the posterolateral viewing portal. The specific drill guide is inserted through the anterior superior portal to create a 2.9-mm medial tunnel immediately adjacent to the articular surface. b Schematic drawing of the step described in a

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Fig. 2
figure 2

The scope is in the posterolateral viewing portal, and the device that allows the creation of an intersecting tunnel (ArthroTunneler, Tornier, Edina, MN, USA) is introduced through the anterolateral portal

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Fig. 3
figure 3

a Arthroscopic view of a right shoulder. The scope is in the posterolateral viewing portal. The arthrotunneler device introduced through the anterolateral portal, the tip of the arthrotunneler inside the previous hole and the arm, is against the upper part of the greater tuberosity. The position of the lateral tunnel is approximately 1.5 cm below the superior tip of the greater tuberosity. b A loaded suture inserter is introduced through the hole of the ArthtroTunneler device. The loop of the ArthroTunneler is moved into the retrieval position, and the suture inserter is removed leaving the suture passed in a transosseous fashion through the greater tuberosity. A transosseous suture passage is created

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Fig. 4
figure 4

Schematic drawing of a right shoulder showing as the suture loop (n. 4) is retrieved through the anterior portal and used to pass 2 or 3 definitive sutures through the anterior tunnel (F G)

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Fig. 5
figure 5

Schematic drawing of a right shoulder showing one possibility of suture management with two tunnels (anterior F/G and posterior E/H) and 6 sutures (1, 2, 3, 5, 6, 7) before to start the cuff repair

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Fig. 6
figure 6

Schematic drawing of a right shoulder showing one possibility of suture management once all sutures are passed through the torn tendon. Note as we have all suture exiting through the anterior portal and then we start to knot from posterior to anterior

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Fig. 7
figure 7

Schematic drawing of one possible pattern of cuff suturing using the transosseous repair. In this case, a mattress suture combined with 2 simple sutures is showed. This represents a very tight repair. However, different suture configurations (more simple and more complex) can be done

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Discussion

Tendon fixation to bone is one of the most critical aspects for rotator cuff repair, and maximizing tendon healing is the primary goal of rotator cuff repair surgery. With advances in arthroscopic surgery, different techniques have been developed to increase the tendon–bone contact area, reconstituting a more anatomic configuration of the rotator cuff footprint and providing a better environment for tendon healing [3, 16–18]. For this purpose, several techniques of double-row suture anchor repair have been proposed [5, 9, 12, 24, 25]. Park et al., in particular, have found that a transosseous-equivalent (TOE) repair using suture bridges can improve pressurized contact area and overall pressure at a repaired rotator cuff insertion [18]. The suture tension for any true transosseous technique provides a more direct tendon-to-bone compression vector. In contrast, the sutures for the suture anchor technique provide a circumferential tension around the tendon but relatively little compression between tendon and bone [18]. The TOE technique, however, requires many anchors, and recent comparative studies show that clinical outcomes are similar to single-row anchor repair [19]. Furthermore, Cho reported a significantly higher incidence of medial failures in transosseous equivalent repair techniques compared to single-row repair [6]. This catastrophic failure close to the musculotendinous junction of the rotator cuff leads to very difficult revision reconstruction.

The traditional open transosseous repair gives excellent results for the fixation of tendon to bone and has represented the gold standard for rotator cuff repair with excellent long-term results [22]. Recently, arthroscopic anchorless transosseous techniques have been introduced to combine the minimal invasiveness of the arthroscopic procedures with the biomechanical advantages of the open procedures. One technique uses an anterior cruciate ligament tibial drill guide to create the holes in the greater tuberosity; the sutures are then passed in the created holes and through the rotator cuff using cannulated needles or suture passers [15, 23]. Fleega introduce the technique of a giant needle in which the needles and sutures pass through the tendon and bone in one single step [7]. In this technique, the author uses a needle with a sharp triangular section that potentially might cut through the tendon. Other authors also proposed a similar technique using a hollow needle instead of a sharp needle (TransOsteoNeedle;Arthrex FL) [8, 26]. Recently, Frick et al. proposed a technique of arthroscopic transosseous cuff repair using an arthroscopic bone needle with the aim to modify and improve the method of suture passage [11]. All of these techniques, however, are difficult to reproduce and standardize. Furthermore, they can have complications related to needle breakage, and the axillary nerve can be also at risk because the exit point of the needle or drill is variable and related to the angle of insertion used by the surgeon.

In this paper, a novel surgical technique that allows surgeons to perform an arthroscopic transosseous (anchor free) repair of rotator cuff tears is reported. With the Arthrotunneler device (Tornier, Edina, MN, USA), it is possible to perform a transosseous technique in a standardized and reproducible fashion, without neurovascular or other risk. In particular, the lateral tunnel is drilled approximately 1.5 cm below the superior tip of the greater tuberosity. This is a very important aspect, because the strength of the fixation of a RCR with a transosseous technique can be increased placing the lateral tunnel more than 10 mm distal to the tip of the greater tuberosity [4]. Clinical and biomechanical evaluation of this exciting technique continues, and this represents a potentially advantageous option for surgeons managing rotator cuff pathology.