Subpectoral biceps tenodesis

Subpectoral biceps tenodesis

Yogesh Joshi, Chetan Bhalla, Mehek Asad and Asad Syed discuss differing techniques for the repair, tenotomy and tenodesis of the long head of the biceps

Biceps pathology in shoulder problems has been studied extensively in literature; controversies still exists for the optimum treatment for the condition. Pathology related to the long head of biceps (LHB) has been described, including LHB tendinitis, LHB tears, superior labral anterior posterior (SLAP) lesions and instability of LHB in the groove. Numerous treatment modalities have been described to treat these conditions which can be broadly classified into repair, tenotomy and tenodesis of the LHB tendon. With advances in arthroscopic techniques and instrumentation, many of the procedures are performed with arthroscopic assistance. Here we describe techniques which have been described to perform biceps tenodesis with a subpectoral approach.

Indications

According to the literature available, indications vary according to the opinion of the authors, and include partial thickness LHB tear >25% diameter, medial subluxation of LHB tendon, tendon subluxation with subscapularis tear, SLAP lesion grade IV and higher, SLAP repair failure and chronic anterior shoulder pain with LHB tendinitis [1–5]. Some studies have indicated that massive, irreparable rotator cuff tears in low demand patients may be treated with LHB tenodesis for pain relief [5,6]. Revision of failed proximal tenodesis or failed tenotomy are a few of the specific indications for subpectoral LHB tenodesis (SPBT), which are not addressed by proximal tenodesis [5].

Rationale

As the site of tenodesis is distal to the bicipital groove, the pathology related to the intertubercular groove itself is eliminated. The advantage of SPBT over tenotomy is the preservation of the muscle length–tension relationship and maintenance of elbow flexion and supination strength [7]. Moreover, it maintains the cosmesis of biceps bulk in the arm. SPBT creates less disruption to the deltoid muscle and sub-pectoral structures compared with arthroscopic tenodesis techniques [5]. It does not require advance arthroscopic skills as it is technically less demanding [5]. Proximal tenodesis may lead to residual redundant tendon, persistent groove pathology or sub-coracoid biceps impingement, which may lead to persistent LHB symptoms [5,8].

Operative technique

The patient is placed in the beach chair position and examination under anaesthesia is performed. A diagnostic arthroscopy is subsequently performed through a posterior portal and the biceps tendon is evaluated for any inflammation, tear, SLAP lesion or instability. Evaluation might be assisted with ‘dry arthroscopy’ to determine the true extent of inflammation of the intra-articular biceps tendon. An anterior portal is then made and a probe is inserted to retract the biceps tendon into the joint and evaluate the intertubercular portion of LHB. Concurrently, attention is given to the biceps anchor and to the superior labrum to evaluate any SLAP injury. Biceps pulley is also evaluated in the rotator interval and any subluxation of the LBT noted. Fraying of the biceps tendon is associated with pathology in approximately 30–50% of instances [9]. The biceps tenotomy is then performed through the anterior portal using arthroscopy scissors or radiofrequency ablator. The free end of the tendon can be left alone or tagged using a polydioxanone (PDS) using a long spinal needle.

The arm is then abducted and externally rotated to palpate the inferior border of the pectoralis major tendon. An incision is made along the axillary crease for better cosmetic outcomes. Dissection is then taken straight down to the bone, avoiding medial vascular and neurological structures. The LHB tendon is then identified after sharp dissection over the fascia overlying the pectoralis major tendon. The plane of dissection is kept below the inferior border of pectoralis major fibres which run horizontally. The LHB tendon is identified by deep palpation of the anterior humerus as a longitudinal tendinous structure. Medial dissection is avoided and the conjoint tendon is gently retracted medially to avoid damage to the musculocutaneous nerve.

The proximal LHB tendon is then retrieved into the wound using a tendon hook. The inferior border of the pectoralis major is then retracted proximally using a blunt right angle retractor. The position of tenodesis is marked at a point 1cm proximal to the inferior border of the pectoralis major tendon. Finally, the tenotomy of the LHB tendon is performed, leaving 2cm of tendon proximal to the musculotendinous junction.

Fixation techniques

Fixing the tendon in the bone tunnel [10]

After preparing the end of the tendon with a Krackow stitch, a bone tunnel is made at the pre-marked site. Two drill holes are made just inferior to it and the suture ends attached to the end of the prepared tendon are passed through the tunnel into the drill holes. The tendon is then pulled into the tunnel by pulling the suture ends, and tied after adequate tensioning (Figure 1).

Figure 1. Diagram of biceps tenodesis using bone tunnels

Fixing the tendon with an interference screw [11]

After preparing the end of the tendon with a Krackow stitch, a bone tunnel is made at the pre-marked site. One of the threads attached to the tendon is passed through the screw and the other outside the screw. The biceps tendon is appropriately tensioned by pulling the thread that passes through the screw. The screw is tightened until it is flush with the bone. The two threads are tied to each other while maintaining the biceps tension (Figure 2).

Figure 2. Biotenodesis screw (Arthrex; Naples, Florida)

Fixing the tendon with suture anchors [7]

For securing the fixation with a suture anchor, the desired site is prepared with a rasp or a burr. He suture anchor is inserted and the tendon end is tied to the anchor after appropriate tensioning. Two suture anchors can be used to tie down the biceps tendon to increase the ultimate load to failure of the construct (Figure 3).

Figure 3. SwiveLock anchor (Arthrex; Naples, Florida)

Fixing the tendon with cortical buttons [13]

This method allows for the fixation of the biceps at its resting length while causing minimal disruption of the cortex of the humerus. It allows in situ fixation of the biceps tendon. The cortical buttons which are used could be either unicortical or bicortical (Figure 4).

Figure 4. Cortical button (Arthrex; Naples, Florida)

Discussion

The biomechanical characteristics of various techniques of fixation for LHB tenodesis with a subpectoral approach show varying opinions in literature. Mazzocca and colleagues have demonstrated that unicortical buttons have a lower ultimate load-to-failure strength in comparison with interference screws, and the diameter of interference screws does not affect the failure strength of the interference screw [14]. Deangelis and colleagues have demonstrated that the ultimate load to failure and stiffness for unicortical button fixation and interference screw fixation were not different [13]. Similarly, Buchloz and co-workers demonstrated that intramedullary cortical button fixation showed no failure during cyclic testing; however, they found a 30% failure rate for the interference screw fixation [15].

Suture anchors also provide an alternative for fixation in SPBT. Tashjian and colleagues came to the conclusion that interference screws and dual suture anchors have similar ultimate failure loads. This cadaveric study also evaluated the stiffness of the suture anchor construct and found that, in initial cyclical loading, the stiffness was lower in comparison with interference screws and it decreased further after about 100 cycles. The ultimate failure strain was significantly higher for suture anchors [16].

Specific complications associated with the sub-pectoral biceps tenodesis are: persistence of bicipital pain; failure of fixation leading to Popeye deformity; damage to neurovascular structures which are in close proximity; and fracture of the humerus [17]. Arora and co-workers have concluded that bicortical buttons may pose an increased risk to the axillary nerve in comparison with unicortical buttons [18]. In a cadaveric study, Dickens and colleagues have demonstrated that the musculocutaneous nerve, radial nerve and deep brachial artery are within 1cm of the standard medial retractor, and are at risk during subpectoral biceps tenodesis [19]. This risk can be avoided by placing the arm in external rotation and careful medial retraction. Failure of tenodesis leading to revision is about 2.7% in comparison with 12% for arthroscopic tenodesis [5,20].

Conclusion

Biceps tendon pathology, although uncommon, is an important source of shoulder pain. It can be addressed with both conservative and operative methods. Surgical options range from tenotomy to tenodesis. Tenodesis can be performed from either a suprapectoral or subpectoral approach by an open technique. Advantages of SPBT include a smaller learning curve, lower complication rates and reduced revision rates. Regarding the fixation method there is no agreed consensus of superiority of one technique over another. SPBT is a valuable technique which should be used to address biceps pathology, however further evidence based research is required to determine the optimal method of fixation.

Staff Writer