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The following is a summary of “Long term (Minimum 10 Years) Survival and Outcomes of Pyrocarbon Interposition Shoulder Arthroplasty,” published in the July 2024 issue of Surgery by Barret et al.
The longevity and effectiveness of Pyrocarbon Interposition Shoulder Arthroplasty (PISA) remain subjects of significant debate. This study aims to evaluate the long-term survival and outcomes of PISA in young, active patients with osteoarthritis (OA) with a minimum follow-up of 10 years.
This retrospective review analyzed data from patients who underwent PISA (InSpyre, Tornier-Stryker, USA) for OA between 2009 and 2012. Arthroplasty survival was documented for 71 patients tracked for at least 10 years. Clinical and radiological outcomes were assessed using radiographs in 62 patients (62 shoulders). The average age at surgery was 60 years (range 23-72), with 50% (31 shoulders) having had prior surgery before PISA. The diagnoses included primary osteoarthritis (POA, n=29), post-traumatic osteoarthritis (PTOA, n=23), and post-instability osteoarthritis (PIOA, n=10). The need for revision surgery is defined as clinical failure. Outcomes were evaluated using the Constant score (CS) and Subjective Shoulder Value (SSV). The average follow-up duration was 11 ± 0.6 years (range 10-14).
The overall survival rate was 90% (95% CI: 82.8-96.8) at 5 years and 87% (95% CI: 79-94.8) at 10 years. Survival rates were 100% for PTOA (type 1 fracture sequelae), PIOA, and 95% for POA with type-A glenoid. Revision surgery was significantly higher in biconcave (type-B2) glenoid cases (44%) compared to concentric (type-A) glenoid cases (2%) (p=0.002). Of the seven patients revised to RSA, five had painful glenoid erosion, and two had bipolar erosion with subsequent greater tuberosity fracture. Additionally, two shoulders with glenohumeral erosion were associated with secondary rotator cuff tears. The mean time to revision was 4 ± 1.7 years. Glenoid wear was predominantly superior (81%) compared to central (19%) (p<0.001). For unrevised shoulders, the mean CS and SSV significantly improved from 39 ± 14 to 70 ± 14 points and from 34% ± 15 to 75% ± 17, respectively (p<0.001).
PISA demonstrates efficiency and durability for treating young, active patients with post-traumatic, post-instability, and primary OA with concentric (type-A) glenoid erosion. However, it is less suitable for patients with biconcave (type-B2) glenoid. Biconcave glenoid and subscapularis tear or insufficiency are significant risk factors for failure and revision.
Source: sciencedirect.com/science/article/pii/S1058274624004798
