Arthroscopic Repair of Batter’s Shoulder

Abstract

Background:

Batter’s shoulder is a condition in which the posterior labrum is typically torn during the baseball swinging motion, producing a traumatic tear and posterior instability. The injury commonly occurs in the batter’s lead shoulder due to repetitive microtrauma, raising concern for switch-hitters due to the cumulative stress of throwing and swinging on the lead shoulder. Instability is commonly caused by a posterior humeral force and relative shoulder adduction, which is most prevalent during a swing attempt at a low and outside pitch.

Indications:

Damage to the labrum during the acute traumatic event can cause residual pain and recurrent instability of the shoulder. Indications include failed conservative management. The patient demonstrated a full-thickness longitudinal tear that was grossly unstable with gentle probing.

Technique Description:

After establishing presence of an unstable posterior labral tear during diagnostic arthroscopy, a 7-o’clock portal is established for the labral repair. A knotless suture anchor construct was utilized for its low-profile features. Care is taken to avoid both tangling of sutures and overtensioning of the repair.

Results:

Patients return to live batting practice at 6 months postoperatively and most patients return to the same level of play following surgical management.

Discussion/Conclusion:

Avoid overtightening of labral repair and subsequent loss of range of motion. Use of a low-profile knotless suture anchor is the senior author’s preferred method of surgical management. A majority of patients surgically managed for unstable posterior labral injuries return to the same level of play.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

The patient is a 15-year-old boy who presents with left shoulder pain and instability. The pain is located in the posterior shoulder and aggravated with swinging a baseball bat. Three months ago, the patient experienced a painful episode of posterior shoulder subluxation while swinging a bat. The physical examination demonstrates a positive O’Briens test, and positive jerk test, signifying a posterior labral tear. The patient failed to improve with conservative treatment, which included ice and antiinflammatories, a 2-month course of physical therapy with a focus on scapular stabilization, and a 2-month break from participating in batting practice.

Hitting mechanics imparts a posterior humeral force with lead arm shoulder adduction, particularly with low and outside pitches that are missed. The mechanism behind batter’s shoulder involves repetitive swings leading to microtrauma, and eventual posterior labral tear of the lead shoulder. Clinically, the batter experiences pain from increased load to the nondominant arm and apprehension to swing at low and outside pitches.

In preoperative imaging, axial and coronal magnetic resonance imaging of the left shoulder demonstrate a small posterior labral tear.

Surgical indications are failed conservative treatment. Contraindications for this procedure are significant surgical comorbidities.

The patient was positioned in the standard lateral decubitus position on a bean bag. An axillary roll and both padding between and underneath the legs was provided. The patient’s cervical spine was maintained at neutral position. The preoperative examination under anesthesia demonstrated full passive range of motion and shoulder instability. The arthroscope was inserted in the glenohumeral joint through the posterolateral viewing portal, which was established slightly inferior and lateral to the posterolateral edge of the acromion. A diagnostic examination demonstrated both a posteroinferior and posterior labral tear. There is no presence of a bony Bankart lesion, rotator cuff tear, superior labrum anterior and posterior (SLAP) tear, nor a significant Hill-Sachs lesion.

An anterior portal was created with insertion of a cannula. With 3-o’clock defined as the anterior portal, the arthroscope was placed in the anterior portal while a posteroinferior 7-o’clock portal was established.

The torn labrum was then debrided with a shaver. Initially, the surgeon did not intend on repairing this patient’s posterior labral injury. However, a labral repair was deemed necessary once the tear was identified to be full-thickness and unstable with gentle probing.

A probe was inserted to determine the extent of the posterior labral tear. Here you can see the full-thickness longitudinal tear and how grossly unstable it was with gentle probing. A drill guide was inserted through the 7-o’clock portal and placed over the glenoid rim. A drill hole was subsequently made followed by insertion of a knotless anchor.

A suture shuttling device was inserted through the posteroinferior 7-o’clock portal.

The blue and white repair suture was then retrieved and loaded into the suture shuttling device. The suture shuttling device was pulled to deliver the blue and white repair suture through the labrum. Care should be taken to avoid tangling during this step. If this occurs, the sutures may be untangled if caught early. The repair suture was then looped on the looped end of the shuttle suture. The nonlooped shuttle suture limb was then pulled on to initiate provisional tensioning of the repair suture. The repair suture and the black and white shuttling suture with the looped end were retrieved together.

After suture tensioning, gentle tugs on the sutures in line with anchor placement are necessary to feed the suture through the locking mechanism. The same steps for knotless anchor placement and labral repair were repeated to manage the posterior labral tear extension. Drill guide placement and drilling of the glenoid rim were preformed followed by insertion of a second knotless suture anchor.

The suture shuttling device was used to pass the repair suture through the labrum. The repair suture and the looped end of the shuttling suture were retrieved and then looped together. The nonlooped shuttle suture limb was then pulled to initiate tensing of the repair suture. A probe was used to check the tensioning of the labral repair. Once satisfied with the repair suture tensioning, the repair suture limbs were then cut.

As you can see, this is the final view of the posterior labral repair with a low-profile knotless construct. The senior author’s surgical preference for shoulder instability is use of a knotted suture anchor repair with capsular plication. However, given the patient’s injury pattern demonstrated during the diagnostic arthroscopy, a low-profile repair construct was preferred.

Potential complications of this procedure include overtightening of the labral repair. Overtightening can result in loss of range of motion. This can be avoided by visualizing suture tensioning and using the probe to check the labral repair tension. Another potential complication is traction neuropraxia. Traction applied to the arm in the lateral decubitus position can lead to damage of the peripheral nerves and the brachial plexus with an incidence of 10% to 30%. However, persistence of the neurological symptoms is rare. To avoid traction neuropraxia, we advocate for the arm to be positioned in 15° forward flexion, 45° of abduction, no more than 10 pounds of traction, and careful portal placement based on the anatomic landmarks.

Postoperatively, the patient is immobilized in an external rotation sling. For the first four weeks following surgery, we recommend passive range of motion in the scapular plane to 90°, pendulum exercises, and restricting internal rotation to 0°. Four weeks following surgery, the sling may be discontinued, and active range of motion is initiated. At the 8-week mark, isotonic strengthening exercises may begin. Four months following surgery, the patient may perform dry swings and at 6 months the patient may resume full batting practice.

The return to sport guidelines for this procedure is broken down into 5 phases: phase 1 is immobilization; phase 2 is passive range of motion; phase 3 is active range of motion and strengthening; in phase 4, the patient may begin to return to hitting beginning on a tee and then advance to soft toss; and in phase 5, the patient may participate in live hitting. In the event that the player is a switch-hitter and the lead batting shoulder is the same as a throwing arm, the return to hitting program is delayed and instead starts with a throwing program. The return to hitting program begins 6 weeks after the throwing program starts. This avoids over stress to the repaired labrum.

Much like the return to throwing programs, there is also a return to hitting program, which consists of 3 phases. Each phase should have a day of rest in-between training to ensure recovery as well as the adaption to stimulus. The use of weighted bats and other warm-up tools that increases resistance are not advised during rehabilitation. Such devices have demonstrated increases in swing speed, and may not be conducive to healing tissue. The player may advance through the program based on soreness rules, which enables the player to modify progression base on their symptoms.

Once the player can begin taking batting practice, the player begins phase 1 with hitting off a batting tee. There are 5 different days of batting tee training, with variations in percent swing effort, ball placement, and number of swings. Phase 2 is soft-toss drills, which simulates differences in pitch placement experienced in a game setting. This phase consists of 5 different days of variations in percent swing effort, ball placement, and number of swings. Phase 3 works in the stretch shortening cycle of hitting kinematics, and the timing of sequential movements during the swing cycle. This is relevant to the game play setting, in which the batter must adjust to a variety of pitch speeds. This phase consists of 4 different days of live batting practice, with variations in percent swing effort, ball placement, number of swings, and pitch type. If muscular or joint stiffness or tenderness is present, the number of rest days and advancement to the next step in the program is adjusted based on when the soreness occurs.

In a manuscript by Wanich at al, patient outcomes in those diagnosed with batter’s shoulder were as follows. In this retrospective review of 14 competitive baseball players diagnosed with batter’s shoulder, 10 were treated with labral repair, 2 were treated with just debridement, and 2 nonoperative treatment. Eleven of the 12 surgically managed return to the same level of play on an average of 5.9 months. Patients were hitting off the tee at 3 months and live hitting at 6 months after surgery. All patients regained full range of motion. A retrospective case series study by Kercher in 2019 consisted of 32 competitive baseball players with posterior labral tears, who underwent arthroscopic repair with a 2-year follow-up. American Shoulder and Elbow Surgeons (ASES) scores improved by an average of 30.9 points following surgery with an average preoperative score of 65.4 and an average postoperative score of 96.3. None of the patients have range of motion deficits. About 94% of the players returned to play, of which 61% returned to the same level of play. Pitchers returned to the same level of play at a lower rate of 41% compared with positional players, who returned to the same level of play at a rate of 86%.

In conclusion, arthroscopic repair of posterior labral tears and baseball players is an effective treatment option to improve pain, function, and ability to return to play.

A study by OKeefe et al in 2020 was a retrospective analysis of 5 patients diagnosed with batter’s shoulder who underwent arthroscopic repair and had a minimum follow-up of 1 year. Both Western Ontario Shoulder Instability and QuickDASH scores were taken, and the scores demonstrated low levels of functional limitations. Hundred percent of these players returned to their previous level of play. All players regained 5 out of 5 strength with forward flexion, shoulder abduction, internal rotation, and external rotation without pain or range of motion deficits.

In conclusion, although this study consisted of a small cohort, all players were able to return to previous level of play, experience improvement in pain and function, and had minimal functional limitations postoperatively.