Glenoid Labral Injuries Are More Common Posteriorly Than Superiorly and Are Combined Across Multiple Areas of the Glenoid

Location of Shoulder Glenoid Labral Tears: A Study of 1763 Consecutive Patients

BACKGROUND

Anterior shoulder labral tearing has historically been considered the most common location of shoulder labral pathology. Recently, smaller studies have reported that posterior labral involvement may be more common than previously recognized.

PURPOSE

To examine the location of surgically repaired labral tears by a single surgeon over a consecutive 23-year period.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 1763 consecutive patients who underwent arthroscopic or open shoulder labral repair by a single seniorsports medicine fellowship-trained orthopaedic surgeon between April 2000 and April 2023 were retrospectively reviewed. Current Procedural Terminology codes were used to identify patients, which included 29806, 29807, 29822, and 29823. Exclusion criteria included isolated shoulder manipulation or glenohumeral joint or labral debridement that did not include repair. Intraoperative glenoid labral tears observed were categorized into 7 broad categories: (1) anterior labral tears, (2) posterior labral tears, (3) superior labral anterior posterior (SLAP) type II tears (A, B, or C), (4) SLAP type V tears, (5) SLAP type VIII tears, or (6) circumferential labral tears (combined SLAP, anterior, and posterior labral tear). Shoulders diagnosed with multiple tear patterns (ie, anterior and posterior) were also noted.

RESULTS

During the 23-year period, 1763 patients underwent arthroscopic or open labral repair; they included 1295 male and 468 female patients, ranging in age from 12 to 70 years, with a mean age of 23.2 years and median age of 19 years. Overall, 28.4% of tears involved the anterior labrum, 64.9% involved the posterior labrum, and 59.6% involved the superior labrum. Regarding isolated tears, 9.3% were isolated anterior labral tears, 19.7% were isolated posterior labral tears, 11.5% involved the anterior and posterior labrum, 22.2% were isolated superior (SLAP type II-IV) tears, 3.63% were isolated SLAP type V tears, 29.8% were isolated SLAP type VIII tears, and 4.1% were circumferential tears.

CONCLUSION

Posterior shoulder labral tearing was more common than anterior tearing in a large consecutive series of 1763 patients who underwent surgical repair. This highlights the importance of posterior labral pathology, which sometimes may be overlooked because of more vague complaints, with pain and loss of function being the most common.

The shoulder joint complex in the throwing motion

The shoulder joint complex in the overhead athlete is organized to effectively transfer the proximally generated forces distally into the arm. The organization also protects the joints and anatomic structures against the repetitive high velocities, large ranges of motions, and compressive, shear, translational, and distraction loads in the overhead motion while placing the hand in the "launch window." Coupling of the movements of the scapula, clavicle, and humerus results in scapulohumeral rhythm (SHR). Effective SHR requires the clavicle and scapula-and, at times, the mechanically linked claviscapular segment-to move the arm into the task-specific position and motion and requires the humerus to move through the ranges of motion to achieve the specific task in the throwing motion. Alterations in SHR can negatively affect effective shoulder joint complex function in the overhead throwing motion and increase injury risk. There are 4 phases of clavicular, scapular, and claviscapular motion that are coupled with arm motion in SHR. The first 3 phases occur in arm elevation motions from 0°-90° and result in the claviscapula and humerus being placed in task-specific positions. The fourth phase is coupling of claviscapular motion with humeral motion to maintain ball-and-socket kinematics throughout the throwing motion. Alterations in this composite motion are termed "scapular dyskinesis." The dyskinesis is considered an impairment of the efficient mobility of the claviscapular segment of the shoulder complex. The most prevalent problem with scapular dyskinesis is the association of scapular protraction and consequent glenoid antetilt with alterations in humeral rotation and posterior humeral head translation to produce shoulder joint internal impingement. Task effectiveness in overhead throwing is also based on and determined by humeral range of motion, precision of humeral motion, and velocity of humeral motion, as well as humeral and arm position in 3-dimensional space. This activity requires maximum ball-and-socket kinematics to create the highest amount of concavity-compression that creates stability for the joint. There are bony and soft-tissue contributions to this stability. Injuries to the glenoid labrum are among the most common deficits that alter concavity-compression. Clinical evaluation of the shoulder joint complex in the injured throwing athlete should be comprehensive and systematic, following an evaluation pathway for proximal and distal causative factors and including observation of humeral motion. This type of evaluation can result in intervention protocols that address the pathoanatomic, pathophysiological, and pathomechanical deficits identified.

Occult, Incomplete, and Complete Posterior Labral Tears Without Glenohumeral Instability on Imaging Underestimate Labral Detachment

PURPOSE

To introduce a classification of posterior labral tear and describe clinical characteristics, magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) findings, arthroscopic findings, and outcomes after arthroscopic repair for patients with posterior labral tears without glenohumeral instability.

METHODS

Sixty patients with posterior labral tear who underwent arthroscopic repair were analyzed retrospectively. Patients with shoulder instability were excluded. Tear patterns were classified into 3 types; occult (type 1), incomplete (type 2), and complete (type 3) based on MRI/MRA studies. A visual analog scale score for pain, American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score for satisfaction, and return to sports were evaluated at a minimum follow-up of 2 years. Computed tomography arthrography was performed at a year follow-up for assess labral healing. The diagnosis was confirmed in arthroscopy, and arthroscopic labral repair without capsular plication was performed.

RESULTS

The mean patient age was 30.4 ± 6.9 years, and all patients were male. Forty-four patients (73.3%) were participating in sports. MRI/MRA studies identified 10 patients with type 1, 18 with type 2, and 32 with type 3 tears. Type 1 tear patients showed a significantly longer symptom duration than those with type 3 (32.5 ± 17.2 vs 18.2 ± 17.1 months; P = .015). In arthroscopic findings, 70% of type 1 tear was confirmed as incomplete or complete tears. The American Shoulder and Elbow Surgeons score improved from 79.6 ± 10.3 to 98.1 ± 3.7, and pain was relieved from 2.4 ± 0.7 to 0.2 ± 0.5 at the last follow-up visit with high labral healing rate (95%). Thirty-nine (88.6%) patients returned to sports at preinjury levels.

CONCLUSIONS

In active young men with shoulder pain during daily activities or sports despite programmed conservative treatment, posterior labral tears should be considered even when MRI/MRA findings are ambiguous. Arthroscopic posterior labral repair without capsular plication provided satisfactory clinical outcomes and a high labral healing rate.

LEVEL OF EVIDENCE

Level Ⅳ, case series.

SLAP Injury and the Superior Labrum

Injuries around the superior labrum are a common cause of shoulder dysfunction and pain. The injuries sustained result mainly from repetitive microtrauma but can also occur following a fall on outstretched hand. Both athletic and general populations can be affected. Injuries to the superior labrum are called superior labrum anterior and posterior (SLAP) tears. Based on cross-sectional imaging findings, the literature defines four main SLAP tears (I–IV) and six extended types (V–X). An accurate description of imaging findings of the SLAP tear type, along with concomitant findings, aids clinicians in treatment planning. We also briefly discuss management options, postoperative appearance of superior labral repair, and the diagnosis of a retear.