Abstract
Surgical management of the throwing shoulder has unique challenges specific to the high demands of the overhead throwing motion. This chapter reviews the various rotator cuff and SLAP (superior labrum anterior and posterior) repair and instability and posterior release techniques used to return these athletes to the field. Successful return to competitive throwing after shoulder surgery requires a combination of thoughtful preoperative planning, meticulous surgical technique, and a comprehensive goal-oriented postsurgical rehabilitation program.
Keywords
anteroinferior labral tears, partial-thickness articular rotator cuff tears, posteroinferior capsular contracture, posterosuperior labral tears and bicep tendon pathology, repetitive throwing, throwing shoulder
Introduction
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Surgical management of the throwing shoulder has unique challenges specific to the high demands of the overhead throwing motion.
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Repetitive throwing places the shoulder in extreme positions under tremendous stress that rival some of the fastest movements in competitive sport.
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There exists a delicate balance separating physiologic adaptation (i.e., capsular laxity, increased humeral external rotation) during normal throwing motion and pathophysiologic changes (i.e., anterior instability, posterior capsular contracture, decreased humeral internal rotation) that may occur in the injured throwing shoulder.
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There are consistent injury patterns that occur in the throwing shoulder, including anteroinferior labral tears, posterosuperior labral tears and biceps tendon pathology, posteroinferior capsular contracture, and partial-thickness articular rotator cuff tears.
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In throwers with chronic insidious pain or instability, surgery is only indicated after failure of conservative management (i.e., optimizing the “kinetic chain,” improvement of scapular dyskinesia, and correction of pathologic humeral rotational deficits).
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Acute traumatic injuries in throwers may require earlier operative management. However, the vast majority are similarly treated with an initial course of conservative management and close observation before surgical intervention is offered.
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Preoperative planning includes detailed history and physical examination, review of imaging studies, and confirmation of the correct diagnosis during examination under anesthesia and diagnostic arthroscopy.
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The goal of surgical management is to recognize and treat pathologic structures while maintaining native joint laxity and range of motion (ROM), which are critical for return to throwing.
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Successful return to competitive throwing after shoulder surgery requires a combination of thoughtful preoperative planning, meticulous surgical technique, and a comprehensive goal-oriented postsurgical rehabilitation program.
Surgical Considerations
Preoperative Planning
Successful surgical management of the throwing shoulder must begin in the clinic setting. Carefully performed history, physical examination, and review of imaging studies gives the surgeon a working diagnosis before operative intervention. This may aid in selection of surgical approach (i.e., arthroscopic vs open) and arthroscopic surgical position (i.e., beach chair vs lateral decubitus) and allows for anticipation of procedure length and any special equipment needs before surgery. In general, the vast majority of surgical interventions in the throwing shoulder can be successfully performed using arthroscopic intervention. This includes capsulolabral and rotator cuff debridement or repair, removal of loose bodies, and synovectomy. Rarely, other procedures may be indicated, including subacromial decompression, distal clavicle excision, decompression of paralabral cysts, suprascapular nerve decompression, or debridement of small capsular exostosis (i.e., Bennett lesion). Open or mini-open approaches are considered for the management of humeral avulsion of the glenohumeral ligament (HAGL) lesions, for complex type IV tears or failed prior repair of the SLAP (superior labrum anterior and posterior) lesion when the surgeon selects to perform subpectoral biceps tenodesis, or for the rare case of complete subscapularis tears with retraction. Open approaches commonly performed in the athletic population are rarely performed in throwers but rather in the setting of complex shoulder instability, particularly when performing open Bankart and capsular shift procedures for contact or collision throwing athletes (i.e., football quarterback) with increased Injury Severity Index (ISI) scores or for athletes with substantial glenoid or humeral bone loss requiring reconstructive procedures.
Anesthesia and Surgical Position
Shoulder surgery in throwing athletes is typically performed under general anesthesia with an interscalene nerve block. Open procedures are performed in the beach-chair or modified beach-chair position. Arthroscopic procedures may be performed in either the beach-chair or lateral decubitus position, based mainly on surgeon experience and preference ( ). With either approach, careful attention is placed on protective padding for critical structures (i.e., axillary roll for lateral decubitus, pillows under knees, and peroneal padding for beach chair). Cerebral perfusion is improved with the lateral decubitus position, and there is less risk of hypotension or bradycardia during the procedure ( ). For arthroscopic management of the majority of conditions of the throwing shoulder, the authors prefer the lateral decubitus position ( ). Advantages of this setup include the use of traction, providing excellent 360-degree access to the glenohumeral joint, including easier access to the inferior labrum and the 6 o’clock position. A relative disadvantage is that repeat dynamic examination under anesthesia (EUA) is more cumbersome, requiring removal and replacement of the traction setup ( ). Additionally, if open surgery is required, the patient may need to be repositioned. However, the majority of the time, this requires only minor readjustment of the torso without repeat preparation and draping. The beach-chair position provides anatomic orientation and easier access for repetitive dynamic EUA ( ). This position may be favored for work limited to the anterior or superior quadrants, rotator cuff, biceps tendon, and Acromioclavicular (AC) joint. However, access to the posterior and inferior quadrants for labral repair or debridement requires substantial technical expertise to gain adequate exposure for appropriate treatment ( ).
Examination Under Anesthesia
Examination under anesthesia is a critical component of the workup and management of the throwing athlete. This should be performed after the induction of general anesthesia and before sterile preparation and draping so that both limbs may be examined. It is important to examine the normal nonoperative extremity to gain better appreciation for the athlete’s native joint laxity and physiologic parameters for ROM ( ). Understanding baseline nonpathologic degrees of humeral internal and external rotation will assist in detecting abnormalities in the throwing shoulder, including residual glenoid internal rotation contracture (GIRD) secondary to posterior capsular contracture ( ). Laxity testing on the noninvolved extremity includes assessment for sulcus sign and multidirectional load and shift of the humeral head ( ). Comparison with the operative extremity allows the surgeon to detect pathologic instability patterns (anterior, posterior, inferior, combined instability) that require surgical attention versus symmetric global hyperlaxity where surgical stabilization may be contraindicated ( ).
Arthroscopic Portal Placement and Diagnostic Arthroscopy
Standard arthroscopic portals are typically used for the management of the throwing shoulder. A posterior viewing portal is established with a #11 blade scalpel. In the lateral decubitus position, the posterior portal is placed generally 1 cm medial and inferior to the posterolateral corner of the acromion. In the beach-chair position, this is typically positioned two fingerbreadths inferior and medial to the posterolateral tip of the acromion. Standard anteroinferior portal is placed next using inside-out technique and a switching stick and dilator set. A transparent cannula is placed superior to the subscapularis under direct visualization, aiming toward the anterior pouch to avoid iatrogenic damage to the glenoid and humeral head. A high rotator interval portal is established using an outside-in technique with an 18-gauge needle for localization, coming just anterior to the leading edge of the supraspinatus tendon. Cannula size is per surgeon preference, ranging from 5.75 to 8 mm. The arthroscopic camera sheath may be switched out for a posterior cannula with attached inflow, allowing for “sheathless” arthroscopy and easy alternation of viewing portal and instrument utilization from any portal. Additional portals such as port of Wilmington and percutaneous transsubscapularis and 7 o’clock portals can be used based on location of pathology and surgeon preference.
Diagnostic arthroscopy is a critical component in the successful surgical treatment of the throwing shoulder ( ). Differentiating normal variants from pathologic entities allows the surgeon to treat relevant pathology and to maintain the integrity and physiologic laxity of native structures. Diagnostic arthroscopy is systematic, reproducible, and goal oriented. It should be hypothesis driven to confirm or refute clinical suspicion based on preoperative workup and EUA findings. It is also helpful to identify relevant abnormalities (i.e., chondral lesions, synovitis, small loose bodies) that may not have eluded diagnostic imaging tests.
Diagnostic arthroscopy begins with the superior labrum–biceps complex. Care must be taken to differentiate sublabral recess or meniscoid appearing normal SLAP variants from pathologic tears. The superior and posterosuperior labrum should be probed and carefully evaluated. Type I, III, and IV SLAP tears are often easily identified. Type II tears are a more challenging diagnostic entity. The arm should be freely mobile and a “peel-back test” performed, visualizing the posterosuperior labrum–biceps and rotator cuff from different vantage points. During this test, the operative arm is taken out of suspension and manually placed at 90 degrees of abduction and 90 degrees of external rotation while visualizing the SLAP–biceps complex. ( Fig. 23.1, A ) This mimics the late cocking and early acceleration phase of the throwing cycle. A positive peel-back test occurs when the SLAP–biceps is unstable and drops medially over the edge of the glenoid, exposing the SLAP footprint ( ). Contact between the posterosuperior glenoid and posterior articular surface of the rotator cuff is also noted during the peel-back test. Partial tears of the undersurface of the infraspinatus tendon may be recognized during this maneuver. In the throwing shoulder, the peel-back test is of major significance because the goal of SLAP repair is to stabilize the SLAP–biceps complex, thereby eliminating the “peel-back mechanism” ( ).
The intraarticular biceps tendon itself should be carefully probed for tears, tenosynovitis, and instability. It is noted that diagnostic arthroscopy does not visualize the entire extent of the extraarticular biceps and may not be able to detect all relevant biceps pathology. The surgeon must rely on presurgical history, physical examination, imaging studies, and clinical suspicion to determine relevant treatment of any “hidden lesions” of the extraarticular biceps tunnel. Next, the glenoid and humeral cartilage surfaces should be inspected and palpated. The joint should be evaluated for synovitis or loose bodies. Care should be taken to evaluate for the presence or absence of glenoid or humeral bone loss, which should be appropriately recorded and measured using standard techniques. The anterior, inferior, and posterior labrum are methodically visualized and probed from anterior and posterior viewing portals. The entire capsulolabral complex is evaluated for presence of labral and capsular tears, noting tissue quality and mobility. The drive-through test is commonly performed in the setting of instability. Although different methods have been used, our preference is to have the surgical assistant apply traction under direct arthroscopic visualization to assess the distance from the humeral head to the glenoid ( ). Successful instability repair should eliminate the drive-through at the conclusion of the procedure ( ). When there is index of suspicion for posteroinferior capsular contracture from EUA, thickening and fibrotic change of the capsule is confirmed with diagnostic arthroscopy, particularly while evaluating for posterior tightness as the arm is brought into internal rotation.
The undersurface of the rotator cuff is inspected for partial articular or full-thickness tears, particularly at the junction between the supraspinatus and infraspinatus. Internal impingement that occurs with the arm placed in abduction/external rotation can demonstrate the pathogenesis rotator cuff tear that requires treatment to provide symptom relief. The rotator cuff should be probed for evidence of intrasubstance delamination. If there is suspicion for a high-grade partial articular tear, the tear can be tagged with a PDS (polydioxanone) suture using spinal needle localization for further classification and visualization in the subacromial space. Additional diagnostic arthroscopy of the subacromial space can help to evaluate for and rule out signs of external impingement (i.e., subacromial bursitis, Coracoacromial (CA) ligament fraying, ossification or thickening, downsloping acromion) or acromioclavicular joint pathology.
Surgical Decision Making
The surgical treatment of the throwing shoulder is “a la carte.” The treating surgeon must understand common injury patterns in order to identify and treat the spectrum of pathologic entities that are typically encountered during these cases. Information learned from preoperative planning, EUA, and diagnostic arthroscopy allows the surgeon to create a problem list and to design and implement a patient-specific surgical plan. It is important to recognize that our evidence-based treatment algorithms for the throwing shoulder may not mirror treatment pathways in nonthrowing athletes, particularly when considering the ultimate goal of effective return to competitive throwing. Treatment strategies that often lead to success in nonthrowing athletes (i.e., rotator cuff repair for high-grade partial tears) have not had the same excellent outcome for return to throwing. This has led to a separate set of guiding principles and surgical strategies in this unique and challenging population. Specific treatments for each of the involved pathologic entities are described in the relevant section below.
Internal Impingement
Slap–Biceps Complex
SLAP tears are a common finding in disabled throwing shoulders. Although the cause of these tears remains controversial, it is well established that unstable SLAP tears contribute to pain, instability, and loss of velocity or accuracy in throwing athletes ( ). The treatment of symptomatic SLAP tear depends on the intraoperative classification ( ). Type I and III SLAP tears are stable injury patterns that are less common in the throwing population and can be treated with arthroscopic debridement ( ). Type II SLAP tears are the most common pattern in throwing athletes ( ). This is an unstable tear pattern that should be treated with arthroscopic stabilization if true peel-back pathology is demonstrated. Type IV SLAP tears are also fairly uncommon in throwing athletes. This injury involves an unstable SLAP tear that extends into the proximal biceps anchor. In high-demand athletes, this lesion should be addressed with surgical repair if possible versus SLAP repair combined with biceps tenodesis. Type V-X SLAP tears occur in conjunction with pathologic instability ( ). In high-demand athletes with symptomatic instability, stabilization of the SLAP extension should be performed alongside combined anterior, posterior, or inferior capsulolabral repair as indicated.
SLAP repair is performed with the standard portals described earlier, including the Nevaiser portal per surgeon preference. The tear is mobilized so that it can be reduced to the footprint on the glenoid without undue tension. The footprint is debrided to a bleeding bed with use of shaver, rasp, or curette. Standard suture shuttling technique is performed to pass either simple or mattress suture through the SLAP tear. Our preference is for the use of simple or cinch stitch with 1.5-mm smooth polyethylene tape secured with two or three knotless biocomposite 2.9-mm anchors ( Fig. 23.1, B ). Knot tying is less desired to avoid iatrogenic damage to the humeral surface from prominent knots. The anchors are drilled and delivered from the anterosuperior portal. Anchors are spaced at least 5 mm apart, stabilizing the superior and posterosuperior labrum as indicated. Typically, the anterior-most anchor is placed just posterior to the biceps anchor to avoid incarceration of the biceps anchor or inadvertent tightening of the superior or middle glenohumeral ligaments and rotator interval. This is critical to avoid overconstraint and subsequent postoperative loss of motion.
At present, the indications for biceps tenodesis in throwing athletes are evolving and remain controversial. In this population, biceps tenodesis should be reserved for treatment of an irreparable biceps tear or pulley injury with subluxation associated with type II or IV SLAP tears and for patients with persistent symptoms associated with a failed SLAP repair ( ). Biceps tenosynovitis or hidden lesions of the extraarticular biceps are challenging to diagnose and manage. Throwers with biceps groove pain but normal-appearing SLAP–biceps complex at arthroscopy should be treated with aggressive conservative management. If symptoms persist and the thrower is unable to return to her or his prior level of activity after index arthroscopy and prolonged rehabilitation, biceps tenodesis may be considered if diagnostic or therapeutic ultrasound-guided injections suggest an extraarticular biceps location of the athlete’s pain.
There is no consensus on the type or location of biceps tenodesis in throwing athletes. There is concern regarding stress riser and fracture risk with larger drill holes for biceps docking, which should be avoided in high-velocity athletes. Our preference is for open subpectoral biceps tenodesis. Intraarticular tenotomy is performed with a basket device. A small axillary incision is placed, and the fascia along the inferior border of the pectoralis major is incised, mobilizing the interval between the pectoralis major and the short head of the biceps. The long head of the biceps is retrieved from the biceps groove using a right-angle hemostat. Blunt neurovascular retractors are placed. All but 15 mm of tendon from the musculotendinous junction is excised, and a locking whipstitch suture is then placed in the remaining tendon. The suture limbs are loaded onto a biceps button. A 3.5-mm-diameter drill hole is placed in the biceps groove at the level of the inferior border of the pectoralis major. The biceps is docked with either unicortical or bicortical button fixation per surgeon preference. Alternatively, the anterior cortex may be overreamed to the diameter of the tendon, and the biceps may be docked within the endosteal space and secured with bicortical button fixation. Fibrin glue and impervious dressing are used for the wound, given the proximity to the axilla.
Rotator Cuff
Partial articular tears of the rotator cuff are commonly encountered in the dysfunctional throwing shoulder with internal impingement ( ). The vast majority are chronic insidious tears or intrasubstance delamination ( ), located at the junction between the supraspinatus and infraspinatus. Acute traumatic high-grade partial or full-thickness tears may also occur on rare occasion. The decision to repair versus debride rotator cuff tears in the throwing shoulder differs from the treatment of a nonthrower. A systematic review of a series of 25 studies found that although recreational athletes return to the same level pre injury, only half of professional and competitive athletes return to an equivalent level of play ( ). As such, caution is recommended before moving forward with surgical repair in this population. Rotator cuff debridement is certainly recommended for low-grade partial articular tears and may be a desirable first-line option for throwers with tears up to 75% of the width of the tendon involvement ( ) ( Fig. 23.2 ). Gentle debridement is performed with a motorized shaver while taking the arm through a controlled ROM arc. Aggressive debridement or conversion of partial- to full-thickness tears is not routinely recommended in this population.