Diagnosis of Posterior and Combined-Type Shoulder Instability: A 10-Year Cross-sectional Study From a Single Military Base

Midterm Outcomes After Revision Posterior Labral Repair in Active-Duty Military Patients

Background

Active-duty military service members experience posterior glenohumeral instability at a rate that far outpaces that of nonmilitary populations. While the outcomes after primary posterior labral repair (PLR) in this population are promising, the outcomes after revision procedures remain poorly described.

Purpose

To report midterm outcomes after revision PLR in a population of active-duty military patients.

Study Design

Case series; Level of evidence, 4.

Methods

Patients who underwent revision PLR from January 2011 through December 2018 by the senior surgeon with a minimum of 5 years of follow-up were deemed eligible for inclusion. Preoperative and postoperative outcome scores for the visual analog scale (VAS) for pain, the American Shoulder and Elbow Surgeons (ASES) score, the Single Assessment Numeric Evaluation (SANE), and the Rowe instability score as well as the rates of return to active duty and sports and the rate of recurrent instability were collected and pooled for analysis.

Results

Overall, 21 patients with a mean follow-up of 77.95 ± 39.54 months met inclusion criteria and were available for analysis. At midterm follow-up, patients who underwent revision PLR experienced significantly improved VAS (from 7.3 ± 1.8 to 2.9 ± 2.4), ASES (from 49.5 ± 12.6 to 79.7 ± 16.7), SANE (from 45.0 ± 14.8 to 80.2 ± 20.3), and Rowe (from 37.6 ± 9.4 to 79.4 ± 24.7) scores. Over 80% of patients also achieved the minimal clinically important difference for these outcome measures; however, only 52% to 62% of patients achieved the Patient Acceptable Symptom State. The return-to-sport rate was 66.67%, and the return to active-duty rate was 80.95%.

Conclusion

While patients who underwent revision PLR experienced improvements in outcomes and a decrease in pain on average, they exhibited rates of return to active-duty and sports that lagged behind those demonstrated in a previous cohort that underwent a primary procedure. Furthermore, the achievement of clinically significant outcomes after revision PLR was less consistent compared with that after primary PLR.

Comparison of Glenoid Bone Loss After Unidirectional Versus Combined Shoulder Instability in a Military Population

Background

While glenoid bone loss (GBL) after anterior shoulder instability correlates with poor functional outcomes, the specific effects of GBL in posterior and combined-type shoulder instability remain poorly characterized, especially in a high-risk military population.

Purpose/Hypothesis

The purpose of this study was to compare GBL between unidirectional anterior or posterior instability versus combined-type instability in active-duty servicemembers. It was hypothesized that total GBL and GBL in the direction of instability would be greater in those with combined-type instability compared with unidirectional instability.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Active-duty servicemembers who underwent shoulder stabilization surgery between January 2010 and December 2019 were eligible for inclusion. Patients with multidirectional instability, concomitant rotator cuff tears, osteochondritis dissecans of the glenoid or humeral head, superior labral anterior-posterior tears, biceps pathologies, and humeral avulsion of the glenohumeral ligament were excluded. Patients were grouped according to direction of instability (anterior, posterior, or combined), and patient characteristics, instability characteristics, suture anchor use, and GBL were compared between the 3 cohorts.

Results

In total, 117 patients met the study inclusion criteria. The mean patient age was 29 years, 89.7% were male, the dominant extremity was involved in 63.2%, 65.8% attributed their injuries to a singular traumatic event, and the mean follow-up was 7.9 years. There was no significant difference regarding patient characteristics, injury mechanism, or follow-up time between the 3 cohorts. As compared with the combined-type instability cohort, mean anterior GBL was greater in the anterior instability cohort (8.00% ± 4.40% vs 4.98% ± 5.26% for combined; P = .012), while mean posterior GBL was greater in the posterior instability cohort (7.44% ± 4.54% vs 4.86% ± 5.69% for combined; P = .024). There was no significant difference in mean total GBL between the combined-type (9.84% ± 7.82%) and either of the unidirectional cohorts (anterior: 8.00% ± 4.40% [P = .231]; posterior: 7.44% ± 4.54% [P = .082]).

Conclusion

GBL in the direction of instability was found to be significantly greater in the unidirectional versus combined-type instability cohorts.

Arthroscopic selective approach to dynamic posterior shoulder instability: long-term follow-up insights

BACKGROUND

The objective of this study is to evaluate the outcomes of arthroscopic capsulolabral repair in patients with structural dynamic posterior instability (Moroder classification B2), analyzing factors associated with inferior clinical outcomes or recurrence. The primary hypothesis is that this surgical approach in patients without static structural changes such as excessive glenoid retroversion or dysplastic glenoids will result in satisfactory clinical outcomes and low failure rates.

METHODS

We conducted observational retrospective analysis in patients diagnosed with posterior structural dynamic instability who underwent arthroscopic capsulolabral repair. Demographic, clinical, and radiologic characteristics were registered, as well as patient-reported outcomes, satisfaction, complications, and failure, with a minimum 2-year follow-up. The association between these outcomes and preoperative factors was investigated.

RESULTS

21 patients were included, with an average age of 38.1 years (range: 27-51 years) and a mean follow-up of 68.7 months (range: 24-127 months). At the final follow-up, the degree of instability was 0 in 19 (90.5%) patients. The overall outcome assessment demonstrated a mean Subjective Shoulder Value score of 82.3 (±15.2), a mean Western Ontario Shoulder Instability score of 460.1 (±471), and a mean Rowe score of 91.5 (±13). Furthermore, a significant portion of patients returned to sport: 71.4% at any level and 57.1% at the previous level, and 71.4% reported satisfaction with treatment, whereas 5 (23.8%) patients had criteria for failure.

CONCLUSION

Arthroscopic capsulolabral repair in selected patients with type B2 posterior shoulder instability without static posterior findings yielded satisfactory clinical outcomes and low failure rates.

Establishing Clinically Significant Improvement for Patients After Arthroscopic Surgery for Shoulder Instability With Large Labral Tears

Background

Patients with large labral tears represent a subset of traumatic shoulder instability cases. Outcomes after arthroscopic stabilization in these patients have been studied less compared with other tears.

Purpose

To establish minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) thresholds for patients after arthroscopic repair of labral tears ≥270°. Patient-reported outcome measures (PROMs) included the Rowe instability score, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) for pain.

Study Design

Case-control study; Level of evidence, 3.

Methods

A total of 52 arthroscopic large labral repairs (52 patients, mean age 28.7 years) performed in male active-duty military patients with a mean follow-up of 79.2 months (range, 24-117 months) met inclusion criteria and were included in the final analysis. All included patients completed the Rowe, ASES, SANE, and VAS pain preoperatively and at final follow-up, and the MCID, PASS, and SCB were calculated for each PROM score. Factors associated with achieving clinically relevant improvement were also calculated.

Results

The MCID, PASS, and SCB, respectively, for each PROM were as follows: 10.4 points, 90, and 35 points for the Rowe; 9.7 points, 80, and 43 points for the ASES; 9.9 points, 87, and 65 points for the SANE; and 1.1 points, 3, and 6 points for VAS pain. More than 90% of patients improved according to the MCID for each PROM, while >75% achieved the PASS threshold for each score. The percentage of patients who improved according to the SCB ranged from 9.6% for the ASES to 75% for the SANE. Maintenance of active-duty status was associated with achieving the MCID for the ASES and SANE, while recurrent instability was associated with lower rates of Rowe MCID achievement and SANE PASS achievement. Higher preoperative scores were also associated with lower rates of achieving clinical improvement.

Conclusion

Thresholds found for the MCID, PASS, and SCB in active-duty patients undergoing surgery for shoulder instability with labral tears ≥270° were similar to those for all-comers with anterior instability. Factors associated with achieving success or lack thereof on PROMs included maintenance of active-duty status and lower preoperative PROM scores.