Superior Labrum Anterior to Posterior Tears and Proximal Biceps Pathology





Introduction


Superior glenoid labrum tears were initially described by Andrews et al. in 1985 in a series of overhead athletes. This injury was further defined by Snyder et al. 5 years later with the terminology as it is known today, superior labrum anterior to posterior (SLAP) tear. The initial classification system was defined at that time, and has since been expanded. The diagnosis and treatment of SLAP tears has increased in recent years. Newer studies have called into question the best management of these lesions, and today controversy exists. SLAP repair, biceps tenodesis, and biceps tenotomy have been proposed as treatment options, and with each comes a unique set of issues and potential complications. Lesions of the long head of the biceps tendon, in isolation from the superior labrum pathology, can also present significant pathology, including tendinopathy, partial tears, or instability in the bicipital groove. These can also be managed surgically with biceps tenotomy or tenodesis.


Many challenges exist in the diagnosis, decision making, and management related to postoperative complications. Patient selection is of great importance in deciding on the treatment options of SLAP repair, biceps tenotomy, or biceps tenodesis. Initial nonoperative management remains the standard for most cases. Intraoperative fixation techniques and concomitant injuries provide another set of issues to consider. Monitoring for postoperative complications, including pain, stiffness, failure of SLAP repair healing, biceps cramping or fatigue, infection, bicipital groove pain, and humerus fracture, is essential. Surgeons must be prepared for and capable of managing these complications.


The purpose of this chapter is to review preoperative, intraoperative, and postoperative issues in the surgical management of superior labrum and proximal biceps pathology. The potential complications will be thoroughly discussed, as well as the appropriate management of those complications. The current literature will be presented to provide an evidenced-based treatment approach.


Preoperative Issues


The challenges of SLAP tears begin with the diagnosis. The clinical presentation can be variable and nonspecific. Patients may present with an insidious onset of pain, possibly from repetitive overhead sports, or an acute injury, such as a fall on an outstretched arm or a traction injury. Physical examination maneuvers for SLAP tears lack the sensitivity and specificity of good diagnostic tests. Even magnetic resonance imaging (MRI) is commonly not definitive, although the use of contrast may improve the diagnostic yield. Paralabral cyst on MRI can make the diagnosis more clear. When the cyst extends to the spinoglenoid notch and compresses the suprascapular nerve, infraspinatus dysfunction occurs that can be apparent on clinical examination. The presence of a compressive spinoglenoid notch cyst remains the best indication for SLAP repair.


Proximal biceps pathology can similarly be challenging on history and physical examination. The history can be nonspecific because of overlapping shoulder pathology. Although tenderness in the bicipital groove and O’Brien sign are sensitive for long head of the bicep pathology, they are not specific. MRI can provide further information, but is still far from perfect for diagnosis of partial-thickness tears and tendinopathy. Given these challenges, the diagnosis of SLAP tears and proximal bicep pathology is problematic. The reported rates of SLAP tears in the literature are low, but the incidence of surgical management has been noted to be increasing. Additionally, there is a trend toward biceps tenodesis as an alternative to SLAP repair. This presents another problem, as incorrect diagnosis can lead to inappropriate surgeries and subsequent complications.


The selection of patients for surgical intervention is important, and especially so for SLAP repair versus biceps tenodesis or tenotomy. Given the variability in patient satisfaction and return to sport with SLAP repair, Boileau et al. proposed bicep tenodesis as an alternative for most patients, and showed improved satisfaction and return to sport in a small series of 25 patients. It has been also been shown that patients over the age of 36 years have a greater likelihood of failure of type 2 SLAP repair. Furthermore, a systematic review showed that SLAP repair in patients over the age of 40 years resulted in decreased satisfaction, increased postoperative stiffness, and increased reoperation rates as compared with younger patients. In a randomized trial, patients over the age of 50 years with type 2 SLAP tear and concomitant rotator cuff tear had better clinical outcomes with biceps tenotomy versus SLAP repair. Therefore, preoperatively, patients should be thoroughly assessed for concomitant pathology, and consideration should be given to biceps tenotomy or tenodesis for patients older than 36 to 40 years.


Further decision-making challenges exist in overhead athletes; the reported rate of return to previous level of play after type 2 SLAP repair varies drastically in the literature (22%–84%). A systematic review of the literature found that 64% of overhead athletes were able to return to the same level of play. This is an especially difficult group because of the demands placed on the superior labrum–proximal biceps complex by overhead throwers. A biomechanical study on SLAP repair showed that placement of a suture anchor anterior to the biceps tendon results in loss of external rotation. Throwers rely on increased external rotation to generate velocity, and a loss could have implications on return to play at the same level.


For type 4 SLAP tears and other proximal biceps pathology, preoperative decision making on biceps tenotomy versus tenodesis should also consider the patient age. Tenotomy is a consideration for older, lower-demand patients, but cramping pain and the Popeye deformity are limitations. Two prospective studies of patients over 55 years of age with rotator cuff tear and bicep lesions showed higher rates of Popeye deformity, but otherwise no difference in clinical outcomes. , Given this literature and the simplicity of tenotomy, it may be the best choice for older patients. Tenodesis has the advantages of maintaining strength, muscle tone, and cosmesis, avoiding deformity, and leading to less cramping pain, and is typically favored for younger, active patients. Although the supination strength advantage may be beneficial for younger patients, the literature has failed to show a significant difference overall in clinical outcome measures.


Intraoperative Issues


Once the decision is made to perform SLAP repair, there are multiple considerations intraoperatively that can have implications for potential complications. The first consideration is portal location for suture anchor placement. Anterosuperior, posterolateral (portal of Wilmington), and Nevaiser portals have all been described. Transrotator cuff approaches have been used for years with good outcomes. This should be done in a percutaneous manner rather than cannulated because of the risk of shoulder pain postoperatively. Recently, a cadaveric study showed that suture anchor placement through the anterolateral portal resulted in a higher rate of glenoid perforation in close proximity to the suprascapular nerve (2.5 mm) as compared with a posterolateral portal. Curved drill guides have also been investigated to further evaluate for safety of anchor placement. The curved drill guide technique through the anterolateral portal resulted in fewer perforations of the superior glenoid, but still a direct hit on the suprascapular nerve when perforation occurred ( Fig. 34.1 ). Given these findings, the posterolateral portal is recommended. Although drill and suture anchor perforation are a concern, fortunately the incidence of clinically relevant suprascapular neuropathy from perforation is very low. However, this must always be on the differential for a patient who has pain and/or weakness postoperatively. It is not possible to predict if perforation occurred based on feel, and smaller glenoids are at higher risk of perforation than larger glenoids.




• Fig. 34.1


Posterior view of a left scapula with suture anchors placed at the 1-o’clock, 2-o’clock, and 6:30 positions. The white arrow is pointing to the perforated 2-o’clock anchor that is overlying the suprascapular neurovascular bundle in the spinoglenoid notch.


Implant options have improved over the years. Early reports of polyglycolic acid bioabsorbable tack fixation was noted to have complications of tack breakage, foreign body reaction, and synovitis. , Subsequent development of poly-L-lactic acid bioabsorbable tacks also resulted in complications of broken tacks (without synovitis) and failure of SLAP tear healing. Results improved with the use of newer bioabsorbable suture anchors. , However, as bioabsorbable suture anchor use increased, it was noted that poly-L/D-lactic acid anchors resulted in greater reoperation rates, and on second-look arthroscopy, there was loss of structural integrity of the anchors, with surrounding synovitis. Biocomposite suture anchors remain popular today and are largely without issue, but it is important to recognize these potential problems in the setting of ongoing pain after SLAP repair. Tying knots or using knotless anchors is largely dependent on surgeon preference, but there is some evidence to suggest better motion with a knotless technique.


Biceps tenodesis has its own set of operative decisions and subsequent potential complications. Location of tenodesis remains controversial; there is no definitive evidence of the best technique, and each technique has unique potential complications. Multiple recent studies have compared arthroscopic suprapectoral tenodesis and open subpectoral tenodesis and found good results without any significant difference between groups. In a matched cohort study of 46 patients, there were no differences, but in the open group, one patient had a superficial wound infection and one had a brachial plexopathy that resolved at 5 months, whereas there were no complications in the arthroscopic group. There were no Popeye deformities or muscle cramping in either group. A large series of 353 cases of open subpectoral biceps tenodesis found two cases of persistent bicipital pain, two with loss of fixation, one case of postoperative infection, and one musculocutaneous neuropathy. Whereas open techniques carry the risks of wound infection and brachial plexus injury, arthroscopic techniques can be associated with residual bicipital groove pain. A series of 17 arthroscopic biceps tenodesis procedures found two cases of residual bicipital groove tenderness in cases where the tenodesis was performed within the bicipital groove, as compared with no cases of tenderness when the tenodesis was distal to the groove. Another series of 127 patients found higher revision rates because of residual groove pain for proximal techniques that did not remove the biceps tendon from the sheath as compared with distal tenodesis techniques. In the largest series, a review of 1526 biceps tenodesis cases, there was no difference in residual anterior shoulder pain between proximal and distal techniques. However, soft tissue tenodesis techniques had greater new-onset anterior shoulder pain, and proximal techniques resulted in greater revisions. We prefer a subpectoral technique with a single 3-mm double-loaded bicomposite anchor placed unicortically to minimize these potential issues. Eccentric placement of the drill guide on the bone with resultant cortical drilling rather than intramedullary drilling is a potential technical pitfall with this technique that can be avoided by clearly identifying the medial and lateral edges of the bone. If cortical drilling occurs, we prefer to just place the anchor in the tract rather than redrilling a second hole that may act as a stress riser.


Nerve injury is a potentially devastating complication from subpectoral biceps tenodesis. A report of four cases of nerve injuries with open subpectoral biceps tenodesis illustrated the spectrum of potential complications: (1) a resolving posterior and medial cord brachial injury without clear cause, (2) a permanent injury to the middle and lower trunks affecting the median and ulnar nerves, (3) an inadvertent transection and tenodesis of the median nerve, and (4) an inadvertent transection and tenodesis of the musculocutaneous nerve. A cadaveric study showed that the musculocutaneous nerve is most at risk because its mean distance to a medial retractor was found to be only 3 mm, whereas the mean distance to the median nerve was 2 cm. Also, the musculocutaneous nerve was closest to the tenodesis site (8 mm) with the shoulder in 45 degrees internal rotation, and furthest away (19 mm) in 45 degrees external rotation. Awareness of the close proximity of the brachial plexus, and specifically the musculocutaneous nerve, is critical in avoiding this complication. The long head of the biceps tendon is the most lateral structure in the subpectoral region, and obtaining adequate visualization to ensure that the long head is directly visualized before removal is paramount. Blindly fishing the long head of the tendon out from keyhole incision is extremely dangerous in light of the above complications, and should never be performed. Blood vessels/bleeding and muscle twitching are the final clues that you are working too medial, as the subpectoral portion of the biceps is tendinous and avascular.


Postoperative Issues


Pain and stiffness are the most common complications after SLAP repair. In a review of 4975 SLAP repairs from the American Board of Orthopaedic Surgery part II database, the surgeon-reported complication rate was 4.7%. The percentage of surgeons’ shoulder cases that were SLAP repairs increased from 9.4% to 10.1% from 2003 to 2008. A subsequent study of the same database showed that the percentage of SLAP repairs for isolated SLAP tears decreased from 69% to 45% and the percentage of biceps tenodesis procedures increased from 2% to 19%, but the complication rates were not reported. In a review of a prospective registry, Brockmeier et al. found five complications in 47 patients (11%) treated with SLAP repair for isolated type 2 SLAP tear. Four developed postoperative stiffness, and only one required repeat surgery. Another series of 107 patients at 5-year follow-up found postoperative pain and stiffness in 14 patients (13%), and these patients required 12 months on average to achieve acceptable shoulder function. Only two patients required capsular release. Although the data are limited, these reports support an initial nonoperative approach to postoperative stiffness. Additionally, 12 patients (11%) had postoperative biceps pain, and three underwent biceps tenodesis. Katz et al. retrospectively reviewed their consecutive series of SLAP repair patients to identify a cohort of patients whose outcomes were complicated by postoperative pain, stiffness, and/or mechanical symptoms. Only 10 of 34 patients (29%) were satisfied with conservative management, whereas 13 of 21 (62%) were satisfied after revision surgery. Only one patient had revision SLAP repair, and only four patients had capsular release. Other revision surgeries were subacromial decompression, labral debridement, or removal of loose hardware or sutures.


Although the cause of pain after SLAP repair remains unclear in most cases, reimaging can be helpful to evaluate for suture anchor perforation or failure of the superior labrum to heal. One series of 12 revision type 2 SLAP repairs showed that all cases had central detachment of the superior labrum directly under the biceps tendon. The primary repairs all had at least one suture anchor anterior to and one posterior to the biceps tendon, and only one patient had partial pullout of a suture anchor. Revision SLAP repair resulted in less than satisfactory outcomes, with a mean American Shoulder and Elbow Surgeons (ASES) score of 73, mean satisfaction rating 6.4 out of 10, 58% return to previous work, and 42% return to previous level of sport. Another series of 24 painful shoulders after SLAP repair found seven without healed superior labrum that underwent revision SLAP repair resulting in fair University of California Los Angeles (UCLA) scores.


Although more rare, humerus fracture after biceps tenodesis is a known complication. In the largest series to date, over 15,000 biceps tenodesis procedures were reviewed, and one intraoperative and 11 postoperative humerus fractures were found. Six occurred with interference screw fixation, whereas three each occurred with cortical buttons and suture anchors. There are consequences to this complication, as only six of the eight patients who were treated nonoperatively and two of the four who were treated operatively regained full range of motion. Surgeons should consider this potential complication, and caution is advised with interference screw fixation. The limited evidence available shows that nonoperative management of a postoperative humeral fracture is reasonable.


When expanding treatment failure beyond the complications of postoperative pain and stiffness, the challenges of SLAP tears are even greater. An analysis of 179 patients that expanded the definition of treatment failure to an ASES score of less than 70, any revision surgery, or failure to return to military duties found a 37% failure rate and a 28% revision surgery rate. This failure rate represents a similarity to the return to sport rate that has been shown in the literature. Two prospective analyses have reported the rate of return to previous level of sport at 62% and 74% for athletes in general, and 59% and 71% for overhead athletes. , As has been previously mentioned, age was shown to be associated with SLAP repair failure.


There are limited data in the literature regarding management of the failed SLAP repair. As previously mentioned, results of revision SLAP repair are less than satisfactory. Weber reported seven revision SLAP repair cases with a mean UCLA score of 30. Park et al. reported on 12 revision SLAP repairs with a mean ASES score of 73, mean satisfaction rating 6.4 out of 10, 58% return to previous work, and 42% return to previous level of sport. Biceps tenodesis as an alternative for failed SLAP repair was investigated in one series of 42 active-duty military patients. A return to active duty and sports was seen in 81%, with clinically and statistically significant improvement in clinical outcome scores and range of motion. A second series of 17 patients undergoing biceps tenodesis as a salvage procedure showed similar good clinical outcome measures, range of motion, and strength. Although revision SLAP repair may be an option for some patients, the evidence in favor of biceps tenodesis is mounting, and this technique is our preferred approach for managing failed SLAP repairs.



References

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Jan 1, 2021 | Posted by in ORTHOPEDIC | Comments Off on Superior Labrum Anterior to Posterior Tears and Proximal Biceps Pathology
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