Open capsular shift with Achilles allograft augmentation for multidirectional shoulder instability: long-term outcomes and implications for patients with Ehlers-Danlos syndrome.

BACKGROUND: Multidirectional shoulder instability (MDI) remains a challenging clinical problem, particularly in patients with connective tissue disorders such as Ehlers-Danlos syndrome (EDS). While MDI may often be successfully treated nonoperatively, surgical intervention is indicated when conservative management fails. While open or arthroscopic capsular shift is often used, allograft tissue augmentation may be required for patients with recurrent instability and deficient capsular tissue. The purpose of this study was to evaluate long-term patient-reported outcomes following open capsular shift with Achilles allograft capsular augmentation in patients with MDI. We hypothesized that Achilles allograft augmentation would lead to improved clinical outcomes and low rates of recurrent instability in this high-risk population.

METHODS: Study approval was obtained by our institutional review board. Patients who underwent open capsular shift with Achilles tendon allograft augmentation for MDI by the senior author were identified retrospectively. Inclusion criteria consisted of MDI due to hypermobile type EDS or MDI without a diagnosed underlying connective tissue disorder. Patients with instability resulting from traumatic injuries were excluded. Outcomes were determined by telephone survey with no physical examination or radiographic follow-up. Five standard patient-reported outcome measures were collected: American Shoulder and Elbow Surgeons, Western Ontario Shoulder Instability Index, Pain Catastrophizing Scale, Tampa Scale of Kinesiophobia, and Subjective Shoulder Value. Recurrent instability, patient satisfaction, pain, and subsequent surgical intervention were also assessed.

RESULTS: Nine patients (10 shoulders) with a mean age of 32 years (range, 22 to 55 years) and mean follow-up of 10 years (range, 2.0-20.3 years) were included. No patients experienced recurrent subluxations or dislocations post-operatively. The mean subjective pain rating was 1.9 (range, 0-5). Eight of 9 patients returned to sports, work, and activities of daily living. Mean American Shoulder and Elbow Surgeons score was 73 (range, 43-100), mean Western Ontario Shoulder Instability Index score was 30% (range, 0.5%-61.9%), mean Subjective Shoulder Value score was 79.5% (range, 50%-100%), mean Pain Catastrophizing Scale score was 2.7 (range, 0-11), and mean Tampa Scale of Kinesiophobia score was 32 (range, 20-41). Two shoulders underwent subsequent shoulder replacement surgery at 8 and 14 years post-operatively.

CONCLUSION: Open capsular shift with Achilles tendon allograft augmentation can be an effective procedure for restoring long-term shoulder stability and functionality in patients with MDI, including those with connective tissue disorders such as EDS.