Arthroscopic Tenoplasty in Congenital Split Biceps Long Head

Abstract

The long head of the biceps brachii tendon arises mainly from the superior glenoid labrum and supraglenoid tubercle. Biceps brachii display anatomic variations, but these are rarely encountered. We report, for the first time, a technique called arthroscopic intra-articular biceps tenoplasty describing restoration of the long head of the biceps tendon using the superior capsule in a case of anomalous congenital split biceps tendon encountered incidentally during diagnostic glenohumeral arthroscopy in a patient who was treated for shoulder instability and SLAP tear.

The long head of the biceps tendon (LHBT) displays numerous anatomic variations, but their clinical relevance remains unclear.¹ The knowledge of these variants may be relevant for both glenohumeral surgery and arthroscopy.² The intra-articular bifurcate anomaly of the LHBT origin is relatively less frequent. This anomaly is usually undetectable on preoperative evaluations such as magnetic resonance imaging and ultrasound because of an interpretational difficulty and lack of preoperative insight toward the anomalous biceps long head. It usually can be found incidentally during arthroscopic procedures for other purposes. The LHBT functions as a humeral head depressor and a secondary restraint to anterior instability, particularly in the abducted and externally rotated position.³ By depressing the humeral head and elevating the glenoid labrum, the LHBT imparts dynamic stability to the glenohumeral joint.⁴ Patients with this variation may have weakening of the rotator cuff. Recognition of abnormalities of the biceps tendon is important because they are a common source of shoulder pain both alone and in combination with abnormalities of the rotator cuff, labrum, and other structures.⁵ Preoperative awareness of the anomalous LHBT is important because it can be the etiologic basis of other structural injuries, such as rotator cuff tears and labral tears.

Case Report and Operative Technique

A 23-year-old right hand–dominant man presented with left shoulder pain and restriction of range of motion. He had a history of anterior shoulder dislocation from a fall onto the ground 3 months earlier, and the shoulder joint had subsequently dislocated 3 times.

The clinical examination showed no tenderness along the route of the biceps tendon. Active range of motion was grossly restricted, with 90° of flexion, 80° of abduction, 20° of external rotation, and internal rotation to L5. The apprehension test, O'Brien test, cross-arm sign, and Speed test were positive. There was no tenderness along the route of the LHBT.

The initial radiograph showed no abnormal findings. A subsequent magnetic resonance arthrogram showed a SLAP lesion and anteroinferior labral tear. The LHBT was present in the bicipital groove. The rotator cuff was intact.

Nonoperative management including oral analgesics and intra-articular or subacromial space steroids and local anesthetic injection had failed to alleviate the patient's symptoms. On the basis of the clinical findings and radiologic evidence, a systematic arthroscopic examination was performed to distinguish abnormal pathology from normal anatomy.

The patient was placed in the right lateral decubitus position with a 30° posterior tilt over the lateral decubitus shoulder with a traction device (Arthrex, Naples, FL), with a traction of 15 lb. A standard posterior portal was established to visualize the glenohumeral joint. On arthroscopic glenohumeral joint examination, an anterior-inferior labral tear extending from the 7-o'clock position to the 9-o'clock position was found. An anterior portal was created in the interval just above the superior glenohumeral ligament, followed by creation of a transtendon portal in the transitional zone between the supraspinatus and infraspinatus muscle.

A standard arthroscopic labral repair was performed with 3 suture anchors (3.7 mm single loaded; Arthrex). The LHBT was found to be bifurcated with 1 band attached to the relatively anterior part of the superior labrum; the other band appeared like a fan-shaped fold adhering to the undersurface of the superior capsule (Fig 1A, Video 1). This thickened fold of tissue deep to the synovium followed the expected course of the LHBT, extending from the bicipital groove aperture to the superior labrum, and was adherent to the undersurface of the supraspinatus muscle but did not attach to the superior labrum; there was no evidence of traumatic rupture or degenerative changes, and the fold was stable on probing. The midsubstance of the superior labrum was found to be torn and nondisplaced (Fig 1B). Arthroscopic scissors (Arthrex), introduced through the anterior portal, incised the capsule along the fold and ended up liberating the posterior superior labrum from the tendon of the biceps (Fig 2A, Video 1). A 4.5-mm full-radius resector and motorized shaver (Dyonics; Smith & Nephew, Andover, MA) and radiofrequency device were inserted through the anterior portal into the glenohumeral joint to split the capsular portion of the biceps remnant off the superior capsule. The fan-shaped biceps capsular tissue was turned into a tubular shape by suturing with FiberWire (Arthrex), as shown in Video 1. No. 2 polydioxanone suture (PDS) (Ethicon, Somerville, NJ) was passed from the aberrant biceps head and labrum through the transtendon portal with an 18-gauge spinal needle (Fig 2B, Video 1). The No. 2 PDS was pulled out through the anterior portal with the aid of a suture retriever (Arthrex). The PDS was then shuttled with No. 1-0 FiberWire. Similarly, another No. 2 PDS was passed with the help of a suture hook (Linvatec, Largo, FL) just posterior to the previous site and later shuttled with FiberWire. Each end of the FiberWire was tied with a sliding-knot technique with a knot pusher (Linvatec) through the anterior portal, which finally secured the repaired tendon (Fig 3, Video 1).

Fig 1.

(A) Arthroscopic image of left shoulder from posterior portal showing bifurcation of origin of LHBT. One small band of the LHBT (white arrow) is attached to the superior labrum; the other main band (black arrow) is fused with the undersurface of the superior joint capsule. (B) Arthroscopic image of left shoulder as viewed from posterior portal showing SLAP tear (black arrow) extending from 11- to 1-o'clock position and attachments of bifurcate biceps tendon (white arrows).

Fig 2.

(A) Arthroscopic image of left shoulder joint from posterior portal showing arthroscopic scissors separating tendon from posterior-superior capsule (dotted line) and posterior band of bifurcate LHBT (arrow). (B) Arthroscopic image of left shoulder from posterior portal showing PDS across both limbs of bifurcate LHBT.

Fig 3.

Arthroscopic image of left shoulder joint from posterior portal showing repair of bifurcate limbs of LHBT with arthroscopic knots.

The patient recovered without any complication, with no further episodes of dislocation or rotator cuff tear.

Discussion

The bifurcate origin of the biceps is a rare variation in which 1 portion of the biceps attaches to the supraglenoid tubercle and the second portion attaches to the posterosuperior capsulolabral tissue.⁶ The case reports addressing the anomalous LHBT origin are rare. The true incidence of a bifurcate origin of the LHBT is unknown.⁶ It is unclear whether there is a need for treatment of this anomaly. Treatment includes symptomatic treatment, benign neglect, subacromial decompression, tenodesis, tenotomy, a stabilization procedure, and labral or rotator cuff debridement or repair (or some combination thereof).

In this study a 23-year-old active male patient had an aberrant biceps, combined with a Bankart lesion and a SLAP tear. We have described a method of restoring the anomalous LHBT by biceps capsule labroplasty. Our attempt at restoration of the LHBT will aid in preventing superior subluxation of the humeral head, as well as the onset of secondary pathologies, considering that our patient had acquired complete range of motion with no episode of dislocation after the procedure. Although this might be the first arthroscopic trial of reconstruction of the LHBT, it has provided stability against further dislocation episodes with a good clinical outcome.

Wahl and MacGillivray⁷ advocated that the LHBT might play a role in the stabilization of the humerus during forceful biceps contractions (as proposed by Kumar et al.⁴) or during resisted overhead glenohumeral motion. In shoulder impingement lesions, rotator cuff tears, and SLAP tears, fraying would occur in the LHBT's abnormal morphology if this function is not preserved.^4,7

In a similar case report from Egea et al.,⁸ an anomalous biceps head was presumed torn and reinsertion of the anterior labrum was performed. The patient subsequently showed no improvement, and the glenoid labrum that had been reinserted was completely destroyed with an additional rupture in the supraspinatus tendon. Repair of the supraspinatus tendon was performed, which subsequently also failed. The lack of a shoulder stabilizer might have led to instability, allowing the humeral head to damage the labrum and trap the cuff against the acromion, which finally resulted in a fracture of the supraspinatus. It can be conceded that the LHBT's role in stabilization of the shoulder joint cannot be overlooked. An attempt at arthroscopic restoration of the LHBT simulated in this study will succeed in avoiding these complications.

Considering the prevalence of instability lesions among few reports and the known role of the LHBT in shoulder stability, we speculate that this anomaly may increase the risk of acquiring shoulder instability. In coherence with Jakanani et al.,⁹ the vector promoting subluxation is posterior to the meridian in the abducted and externally rotated position. It can be extrapolated that the inability of the aberrant biceps anatomy to counteract this vector in our patient has contributed to transfer of the injury at the dislocation to the superior labrum in addition to the anterior-inferior capsulolabral complex.⁹ Patients with the described variation may have weakening of the rotator cuff. These anomalies may increase the risk of acquiring shoulder instability.² Thus recognition of abnormalities of the biceps tendon is important because they are a common source of shoulder pain both alone or in combination with abnormalities of the rotator cuff, labrum, and other structures. Knowledge of this anomaly can be helpful in explaining unusual signs on magnetic resonance imaging. The cognizance of the anomalous biceps tendon in the etiology of other structural injuries, such as rotator cuff tears and labral tears, is of paramount importance.^2,10 Such knowledge helps to avoid an incomplete diagnosis, leading to treatment failure. Arthroscopic tenoplasty of the LHBT might have the advantage of providing counteractive restraint against a posteriorly directed vector causing anterior dislocation; moreover, theoretically, it not only restores biceps anatomy but also stabilizes the joint against further recurrences.

Our study has limitations: the lack of second-look arthroscopic surgery to access the outcome of the procedure and the inclusion of only 1 patient, given the rare incidence of anomaly. However, on the basis of the smooth recovery of our patient, with no further episode of dislocation, the role of this anatomic variant in the development of instability or SLAP tears cannot be denied. Therefore, considering the important role of the biceps in shoulder biomechanical functioning, we would strongly recommend that a trial examining anatomic restoration of the anomalous biceps long head could be valuable to prevent further damage to the anterosuperior rotator cuff and superior labrum, rather than just performing tenotomy. Further study and larger numbers of patients are required to affirm the relation between these LHBT anomalies and shoulder instability.

Supplementary Data

Video 1

Arthroscopy of left shoulder joint in lateral decubitus position, with standard posterior viewing portal and anterior and transtendon working portals, showing tenoplasty of bifurcate limbs of LHBT.