Variability of glenoid labral tear patterns: a study of 280 sequential surgical cases

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.

Does glenoid version affect the post-operative clinical outcome after repair of posterior labral tear: A retrospective study

Introduction

Posterior shoulder instability and consequent labral tear have been predominantly associated with retroversion of the bony glenoid and chondrolabral version. However, literature concerning the degree of glenoid and chondrolabral version and clinical outcomes following labral repair is scarce.

Methods

A retrospective cohort study was undertaken among patients with posterior shoulder instability who had undergone arthroscopic isolated posterior labral repair. The MRI was used to assess the bony and labral variations of the glenoid using the Friedman method and further categorized as either anteverted or retroverted glenoid. American Shoulder and Elbow Surgeons (ASES), Oxford Shoulder Score (OSS), and Single Assessment Numeric Evaluation (SANE) scores were used to evaluate pre- and postoperative clinical outcomes at a minimum follow-up of one year.

Results

33 shoulder MRIs performed at our institution were available for radiographic analysis. Among the 33 shoulders that underwent posterior shoulder capsulolabral repair, 23 were available for clinical follow-up for at least one year (range, 12-108 months). The mean (±SD) labral version and bony version were -3.98 (±5.68) and -2.83 (±5.20), respectively. The mean (±SD) postoperative ASES, Oxford score, and SANE scores for all participants were 84.04 (±14.14), 43.38 (±3.81), and 78.57 (±17.40), respectively. However, the difference in clinical outcomes in patients with anteverted or retroverted glenoid versions was not statistically significant.

Conclusion

Our study concludes a strong correlation between posterior glenohumeral instability and higher degree of glenoid retroversion. Nevertheless, variations in the glenoid version appear to have no significant impact on clinical outcomes.

Level of study

Level IV, retrospective cohort.

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.

Outcomes After Revision Posterior Shoulder Capsulolabral Repair in Adolescent Athletes

Background

Few studies have evaluated the outcomes of posterior arthroscopic capsulolabral repair in adolescents, especially with regard to outcomes after revision repair.

Hypothesis

Adolescent athletes who undergo revision arthroscopic posterior unidirectional capsulolabral repair will have similar outcomes and return to play when compared with adolescent athletes who underwent primary arthroscopic posterior unidirectional capsulolabral repair.

Study Design

Cohort study; Level of evidence, 3.

Methods

Data were reviewed from patients who underwent posterior shoulder stabilization between 2000 and 2019 and had a minimum follow-up of 2 years. Patients <11 and >19 years of age and those with multidirectional instability were excluded. Revision surgery was defined as repeat arthroscopic posterior capsular repair. The ability to return to sport (and level of sport), clinical outcomes scores (American Shoulder and Elbow Surgeons [ASES] and visual analog scale for pain), and patient-reported perception of range of motion, strength, and satisfaction were recorded. Comparisons between the primary and revision cohorts were made using the chi-square or the Mann-Whitney U test.

Results

Included were 180 adolescent patients (182 shoulders) who underwent a primary unidirectional posterior stabilization, with an average follow-up of 6.1 years. Of these patients, 17 patients required revision surgery (9.3% revision rate). At the final follow-up, patients who underwent revision surgery returned to sport at similar rates to those who did not (70.6% vs 85.9%; P = .095) and were similarly likely to return to their presurgery level of play (41.1% vs 23.7%; P = .10). The no-revision patients had higher ASES scores (76.1 vs 87.1; P = .007) as well as less pain and improved subjective range of motion scores. However, both groups had similar subjective strength scores, and both reported that surgical repair was satisfactory (no revision, 93.2% vs revision, 88.2%; P = .45).

Conclusion

Adolescent athletes had a low risk of revision surgery and frequently returned to play after arthroscopic posterior capsulolabral repair, often at a lower level of play. Those who required revision surgery had poorer outcome scores but still reported a high rate of satisfaction.

Histological Analysis of Regenerative Properties in Human Glenoid Labral Regions

BACKGROUND

The healing capacity of the human glenoid labrum varies by tear location. Current evidence suggests that the healing capacity of meniscal and cartilage injuries relates to cellular composition and vascularity. However, little is known about the histological characteristics of the glenoid labrum and how they may affect healing potential in specific anatomic regions.

HYPOTHESIS

Regenerative characteristics of the glenoid labrum differ based on the anatomic region.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Human glenoid labra from fresh unpreserved cadavers were transversely sectioned in different anatomic regions. Masson trichrome stain was used to determine dense and loose extracellular matrix regions and vessel densities. Hematoxylin and eosin, Ki-67+, and CD90+/CD105+ stains were performed to determine total, proliferative, and progenitor cell densities, respectively. Regression models demonstrated relationships between vascular area, progenitor cell quantity, and probability of successful operation.

RESULTS

Among all labral aspects, the superior glenoid labrum had the highest percentage (56.8% ± 6.9%) of dense extracellular matrix or avascular tissue (P < .1). The vascular region of the superior labrum had the fewest total cells (321 ± 135 cells/mm2; P < .01) and progenitor cells (20 ± 4 cells/mm2; P < .001). Vascular area was directly correlated with progenitor cell quantity (P = .006002). An increase in probability of successful operation was associated with a linear increase in vascular area (R2 = 0.765) and an exponential increase in progenitor cell quantity (R2 = 0.795). Subsequently, quadratic models of vascularity and progenitor cell quantity around the labral clock were used to assess relative healing potential. Quadratic models for percentage vascular area (P = 6.35e-07) and weighted progenitor cell density (P = 3.03e-05) around the labral clock showed that percentage vascular area and progenitor cell quantity increased as labral tissue neared the inferior aspect and diminished near the superior aspect.

CONCLUSION

Anatomic regions of the glenoid labrum differ in extracellular matrix composition, vascularity, and cell composition. The superior glenoid labrum is deficient in vascularity and progenitor cells, which may explain the high failure rates for repairs in this location.

CLINICAL RELEVANCE

Improved understanding of the composition of distinct glenoid labral positions may help to improve therapeutic strategies for labral pathology.

A Bibliometric Analysis of the Most Cited Research on Humeral Avulsions of the Glenohumeral Ligament: A Paucity of High-Level Evidence

Purpose

To identify the 25 most-cited articles on humeral avulsion of the glenohumeral ligament (HAGL) lesions and characterize them based on number of citations, citation density, source journal, year of publication, geographic origin, article type, and level of evidence.

Methods

The Science Citation Index Expanded database was queried for all possible publications regarding HAGL lesions. The 25 most-cited articles from 1976 to 2021 relevant to the topic were selected for further analysis. Articles were characterized based on the number of citations, citation density, year of publication, source journal, country of origin, article type, article subtype, and level of evidence.

Results

The number of citations for individual articles ranged from 21 to 182 (mean ± standard deviation: 44.72 ± 36.87). Ten countries contributed to the 25 most cited articles, with 14 of the 25 (56%) articles published in the United States. Furthermore, the top 25 cited articles were published in 9 journals, with the majority in Arthroscopy-The Journal of Arthroscopic and Related Surgery (n = 15, 60%). There were 15 (60%) articles classified as "Clinical," 9 (36%) as "Review/Expert Opinion," and 1 (4%) as "Basic Science." All clinical studies met the standard for level IV evidence.

Conclusions

This bibliometric analysis provides a list of the 25 most cited articles related to HAGL lesions, providing a reference of impactful articles for medical educators. The lack of high level of evidence "Clinical" studies demonstrates that higher-quality research is needed to establish guidelines for the treatment and management of HAGL lesions.

Clinical Relevance

A list of the 25 most-cited articles regarding recurrent glenohumeral instability can serve as a comprehensive reference for practitioners, educators, researchers, and orthopaedic trainees.

Two paleopathological cases suggestive of paralabral cysts of the shoulder

OBJECTIVE

To undertake differential diagnosis of scapular bone defects found in two medieval skeletons buried in different necropoles of Friuli Venezia Giulia (Italy) and to evaluate the clinical significance of paralabral cysts in the context of shoulder pathology.

MATERIALS

Individual JoT36 is an adult male exhumed from a necropolis belonging to a rural agricultural settlement dated to the 10th to 11th century A.D. Individual CIVT58 is an adult male from a Langobard necropolis dated to 630-670 A.D.

METHODS

Macroscopic examination of the skeletons was performed using standard osteological methods and review of pertinent clinical literature to assist differential diagnosis.

RESULTS

Between the glenoid cavity and the spinoglenoid notch of the right scapula of JoT36 there is a multilocular circular defect adjacent to the glenoid rim. On the neck of the left scapula of CIVT58, immediately above the spinoglenoid notch, there is a unilocular circular depression. In both cases, the cortical bone appears smooth without any evidence of erosion or sclerosis.

CONCLUSIONS

Skeletal findings and historical/archaeological contexts of both cases are compatible with the diagnosis of paralabral cysts.

SIGNIFICANCE

Paralabral cysts are relatively frequently observed in clinical settings but very few examples have been documented in paleopathological literature. This study seeks to improve recognition and interpretation of this pathology in historical/archaeological contexts.

LIMITATIONS

Findings from a case report can neither generate epidemiological information nor be generalized.

SUGGESTIONS FOR FURTHER RESEARCH

Identification of new cases may add valuable information about lifestyles and related shoulder pathologies in ancient times.

Increased superior translation following multiple simulated anterior dislocations of the shoulder

PURPOSE

Recurrent shoulder dislocations can result in kinematic changes of the glenohumeral joint. The number of prior shoulder dislocations may contribute to increased severity of capsulolabral lesions. The kinematics of the glenohumeral joint following multiple dislocations remain poorly understood. The purpose of this study was to assess the kinematics of the glenohumeral joint during anterior dislocations of the shoulder, and more specifically, altered translational motion following multiple dislocations. The kinematics of the glenohumeral joint were hypothesized to change and correlate with the number of dislocations.

METHODS

Eight fresh-frozen cadaveric shoulders were dissected free of all soft tissues except the glenohumeral capsule. Each joint was mounted in a robotic testing system. At 60 degrees of glenohumeral abduction, an internal and external rotational torque (1.1 Nm) were applied to the humerus, and the resulting joint kinematics were recorded. Anterior forces were applied to the humerus to anteriorly dislocate the shoulder and the resulting kinematics were recorded during each dislocation. Following each dislocation, the same rotational torque was applied to the humerus, and the resulting joint kinematics were also recorded. A repeated-measures analysis of variance (ANOVA) was used to compare the kinematics following each dislocation.

RESULTS

During the 7th, 8th, 9th, and 10th dislocations, the humerus significantly translated superiorly compared with the shoulder during the 1st dislocation (p < 0.05). Following the 3rd, 4th, 5th, and 10th dislocations, the humeral head significantly translated superiorly compared with the shoulder following the 1st dislocation in the position of 60 degrees of abduction in response to external rotation torque (p < 0.05).

CONCLUSION

Multiple anterior shoulder dislocations lead to abnormal translational kinematics and result in increased superior translation of the humerus. This may contribute to pathologic superior extension of capsulolabral injuries. Superior translation of the humerus with overhead motion in the setting of recurrent instability may also place the shoulder at risk for extension of the capsulolabral injuries.

Biomolecule-releasing bioadhesive for glenoid labrum repair through induced host progenitor cell responses

Glenoid labral tears occur with repetitive dislocation events and are common injuries observed in shoulder arthroscopic procedures. Although surgery can restore shoulder anatomy, repair is associated with poor clinical outcomes, which may be attributed to the poor regenerative capability of glenoid labral fibrocartilage. Thus, this study was designed to assess whether in situ tissue regeneration via biomolecule-stimulated recruitment of progenitor cells is a viable approach for the regeneration of labral tears. We developed a click chemistry-based bioadhesive to improve labral repair and reduce local inflammatory responses due to trauma. Additionally, we previously identified the presence of progenitor cells in the human labrum, which can be recruited by platelet-derived growth factor (PDGF). Thus, we hypothesized that PDGF-releasing adhesives could induce the regenerative responses of progenitor cells at the injury site to improve labral healing. In a rat glenoid labral tear model, we evaluated the effect of PDGF-releasing adhesives on promoting progenitor cells to participate in labral tear healing. After 3 and 6 weeks, the labrum was histologically analyzed for inflammatory responses, progenitor cell recruitment, proliferation, and extracellular matrix (ECM) production (collagen and glycosaminoglycan). Our results showed that adhesives alone considerably reduced local inflammatory responses and labral tissue dissolution. PDGF-releasing adhesives significantly increased progenitor cell recruitment, proliferation, and ECM production. These results demonstrate that by accelerating autologous progenitor cell responses, PDGF-releasing adhesives represent a novel clinically relevant strategy to improve the healing of glenoid labral tears.

SLAP Repair Versus Biceps Tenodesis in Patients Younger Than 40 Years: A Cost-Effectiveness Analysis

BACKGROUND

The surgical management of type II superior labrum anterior and posterior (SLAP) tears in patients younger than 40 years is controversial, but growing evidence suggests comparable outcomes between primary SLAP repair and primary biceps tenodesis, with lower rates of reoperations after primary biceps tenodesis. Given the relatively similar patient-reported outcomes, cost-effectiveness analyses of direct and indirect costs associated with the two procedures propound a valuable comparative technique.

HYPOTHESIS

In this value-based comparison of SLAP repair versus biceps tenodesis, we hypothesized that biceps tenodesis would be more cost-effective than SLAP repair in patients younger than 40 years.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 4.

METHODS

A 1-month Markov cycle was simulated to reflect 10 years of health outcomes. Health states were selected based on outcomes that are especially important in assessing indirect costs for a younger, active patient population: return-to-sport rates, which demonstrate a return to baseline function, and reoperation rates. Transition state probabilities were obtained through an index systematic review and meta-analysis comparing labral repair and biceps tenodesis for the treatment of type II SLAP lesions in patients younger than 40 years. Health state utility and cost values were obtained from accepted values denoted in existing literature.

RESULTS

Both primary SLAP repair and primary biceps tenodesis yielded an average expected 8.1 quality-adjusted life years over the 10-year period. The average cost (in 2021 US$) was $16,619 for biceps tenodesis and $19,388 for SLAP repair.

CONCLUSION

In a younger patient population, SLAP repair and biceps tenodesis had comparable quality-adjusted life years and utility in the treatment of type II SLAP tears; however, SLAP repair cost $19,388, while biceps tenodesis cost $16,619, reflecting a 14% cost savings with biceps tenodesis. These findings can be extrapolated to further establish the role for these procedures in treating SLAP tears.

Lower Reoperation and Higher Return-to-Sport Rates After Biceps Tenodesis Versus SLAP Repair in Young Patients: A Systematic Review

Purpose

To evaluate patient-reported outcomes, return to sport, and adverse events after SLAP repair versus biceps tenodesis (BT) in a young patient population undergoing treatment of SLAP tears.

Methods

We performed a systematic review and meta-analysis of the PubMed (MEDLINE), Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), and Web of Science databases for comparative studies discussing outcomes after SLAP repair and BT in patients younger than 40 years with at least 1 year of follow-up.

Results

Four studies were included, comprising a total of 274 patients who underwent treatment of SLAP tears with SLAP repair (169 patients) or BT (105 patients). Most patients were male patients (79.8%) and athletes (74.5%). Preoperative and postoperative pain visual analog scale scores decreased similarly in both groups (range, 6.6-6.7 preoperatively to 0.8-2.6 postoperatively in SLAP repair group vs 5.6-7.3 preoperatively to 0.7-1.9 postoperatively in BT group). Similar and substantial American Shoulder and Elbow Surgeons Standardized Shoulder Assessment score increases were observed after both procedures (range, 40.6-45.8 preoperatively to 75.4-92.0 postoperatively in SLAP repair vs 41.9-55.0 preoperatively to 85.7-91.2 postoperatively in BT group). Patient satisfaction rates were similar but showed slightly higher ranges after BT (8.5-8.8 vs 8.0-8.2). Rates of return to sport were higher after BT (63%-85% vs 50%-76%), with higher odds of returning to sport after BT reported by all studies. Surgical complications were rare after SLAP repair and BT. Rates of reoperation were substantially higher after SLAP repair (3%-15% vs 0%-6%), with 3 of 4 studies reporting no reoperations after BT. BT comprised 78% to 100% of reoperation procedures after SLAP repair.

Conclusions

Postoperative pain, function, and patient satisfaction were similar after SLAP repair and BT in patients younger than 40 years. There are higher rates of reoperation and lower rates of return to sport after SLAP repair than after BT.

Level of Evidence

Level III, systematic review of Level III studies.

Disabled Throwing Shoulder: 2021 Update: Part 2-Pathomechanics and Treatment

The purpose of this paper is to provide updated information for sports healthcare specialists regarding the disabled throwing shoulder (DTS). A panel of experts, recognized for their experience and expertise in this field, was assembled to address and provide updated information on several topics that have been identified as key areas in creating the DTS spectrum. Each panel member submitted a concise presentation on one of the topics within these areas, each of which were then edited and sent back to the group for their comments and consensus agreement in each area. Part two presents the following consensus conclusions and summary findings regarding pathomechanics and treatment, including (1) internal impingement results from a combination of scapular protraction and humeral head translation; (2) the clinically significant labral injury that represents pathoanatomy can occur at any position around the glenoid, with posterior injuries most common; (3) meticulous history and physical examination, with a thorough kinetic chain assessment, is necessary to comprehensively identify all the factors in the DTS and clinically significant labral injury; (4) surgical treatment should be carefully performed, with specific indications and techniques incorporating low profile implants posterior to the biceps that avoid capsular constraint; (5) rehabilitation should correct all kinetic chain deficits while also developing high-functioning, throwing-specific motor patterns and proper distribution of loads and forces across all joints during throwing; and (6) injury risk modification must focus on individualized athlete workload to avoid overuse. LEVEL OF EVIDENCE: V, expert opinion.

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

Purpose

To categorize arthroscopically observed labral injuries to include location on the glenoid and frequency of the injuries in each location.

Methods

Patients undergoing arthroscopic labral surgery between January 2018 and June 2020 were reviewed. Inclusion criteria for labral injury were consistently applied and included history, clinical examination and imaging findings, and failure of rehabilitation. Exclusion criteria included arthritis, adhesive capsulitis, and previous surgery. Injury locations were categorized into superior, anterior, and/or posterior areas on the glenoid and as isolated in one area or combined in more than one area. Injury patterns also were evaluated. Interrater and intrarater agreement was assessed between 2 raters for injury location and tear pattern for 22 randomly assigned cases.

Results

In total, 167 cases met the inclusion criteria. Injuries were found in all areas. Combined injuries were found almost twice as often as isolated injuries (63.5% vs 37.5%). Isolated posterior injuries had the greatest frequency of all specific injury types (26.3%). Isolated superior injuries (SLAP 2-4) had a frequency of 7.2%. Tear patterns included peel back, separation/split, insubstance injury, peripheral rim flattening, and extension into the posterior inferior glenohumeral ligament. Interrater was excellent for all tear locations (intraclass correlation coefficient ≥0.85) whereas intrarater agreement was good to excellent (intraclass correlation coefficient ≥0.63).

Conclusions

Labral injuries that are associated with clinical symptoms can occur as isolated or combined types in the superior, anterior, and posterior glenoid areas and can display multiple injury patterns. Combined types of injuries are almost twice as common as those that are isolated in one area. Posterior injuries, isolated or combined, are frequent but superior injuries are less common

Level of Evidence

Level IV, therapeutic case series.

Arthroscopic repair of inferior glenoid labrum tears (Down Under lesions) produces similar outcomes to other glenoid tears

PURPOSE

Inferior glenoid labral tears are an uncommon but distinct shoulder injury. Only a small number of studies have reported outcomes following arthroscopic repair. The aim of the current study was to report minimum 2-year outcomes following inferior labral repair and to compare outcomes and risk factors associated with the injury to non-inferior labral tears. Whether preoperative MRI or MRA identified inferior labral tears was also assessed.

METHODS

A prospective study of 162 consecutive patients undergoing arthroscopic glenoid labral repair, excluding isolated superior labral tears, was conducted. Of the 130 patients available for follow-up, 18 (13.7%) had an inferior labral tear ("Down Under lesion"), the remainder had anterior, posterior or mixed anterior/posterior lesions that did not include the inferior pole. Mean follow-up time for the Down Under group was 44 months (SD 10, range 27-57), and 30 months (SD 14, range 4-60) for the non-Down Under group. Postoperative outcomes included the Oxford Shoulder Instability Score and recurrent instability. Associations between Down Under lesions and injury mechanism, instability at presentation, recurrent instability and family history were assessed with multivariable logistic regression. Preoperative MRI or MRA reports by radiologists were examined to determine if Down Under lesions were identified.

RESULTS

Oxford Shoulder Instability Scores indicated that most patients in both groups had little pain or shoulder problems postoperatively (average Oxford Score 41; 48 = no symptoms). Oxford Scores were not significantly different between the Down Under and non-Down Under groups. Four patients (22.2%) in the Down Under group had recurring symptoms (pain and instability) compared to 12 (10.6%) in the non-Down Under group; this difference was not statistically significant (adjusted OR 1.09, 95% CI 0.19,4.77). Family history of shoulder instability was positively associated with a Down Under lesion (adjusted OR 5.0, 95%CI 1.51,16.7). MRI or MRA identified 52.9% of Down Under lesions.

CONCLUSION

Down Under lesions were an infrequent type of glenoid labral injury, yet postoperative outcomes were similar to other labral tears. Patients with Down Under lesions had a significant risk factor due to family history of shoulder instability. MRI and MRA could not reliably identify Down Under lesions.

LEVEL OF EVIDENCE

Level III.