Long-Term Clinical Outcomes after Microfracture of the Glenohumeral Joint: Minimum 7-Year Follow-up

Abstract

Purpose: Microfracture is an effective surgical treatment for isolated, full-thickness cartilage defects of the knee. Currently, there is a paucity of data available on outcomes following microfracture in the glenohumeral joint, with no studies reporting on long-term clinical outcomes. The purpose of this study is to present long-term clinical outcomes of patients undergoing microfracture of full-thickness articular cartilage defects of the glenohumeral joint. Methods: Sixteen consecutive patients (17 shoulders) who underwent arthroscopic microfracture of the humeral head and/or glenoid surface between March 2001 and January 2008 with a minimum follow-up of 8 years were retrospectively reviewed. All patients completed preoperative surveys containing the visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, and simple shoulder test (SST), short-term postoperative surveys containing the VAS, ASES, and SANE, and long-term postoperative surveys containing the single numeric assessment (SANE), and VAS outcomes scores. Complications and reoperations were analyzed. Failure was defined by reoperation, including conversion to arthroplasty. Results: Of the original 16 patients (17 shoulders), 13 shoulders in 12 patients (6 males, 6 females) were available for follow-up at an average 10.4 ± 1.5 years following microfracture (range, 8.9 to 15.7 years), for an overall clinical follow-up rate of 75% (Table 1). The patients had an average age of 36.1 ± 12.9 years at time of microfracture. The average size of humeral and glenoid defects was 5.07 cm2 (range, 1.0-7.8 cm2) and 1.66 cm2 (range, 0.4-3.8 cm2), respectively. Four patients (4 shoulders) underwent at least 1 reoperation and were considered failures for an overall failure rate of 23.5% (Table 2). The average time to first reoperation was 1.8 years following microfracture (range, 0.2 to 2.8 years). Of these 4 patients, 3 progressed to shoulder arthroplasty (1 initially, 2 after additional arthroscopic procedures) for an overall arthroplasty rate of 17.6%. The average time to arthroplasty was 5.7 years (range, 0.2 to 9.6 years). Of the patients who did not progress onto arthroplasty, there were statistically significant improvements in VAS and ASES compared to preoperative values (both p < 0.001) at short-term follow-up at 28 months. There was no significant change in VAS and SANE between short-term follow-up and 8+ year follow-up. When compared to short-term follow-up at 28 months, in which 3 patients had already been considered failures, 1 additional patient progressed to failure at 2.7 years after the original microfracture and 1 failed patient further progressed to arthroplasty at 9.6 years after the original microfracture. Conclusions: The management of full-thickness symptomatic chondral defects of the glenohumeral joint is challenging. For some patients, microfracture can result in improved function and reduced pain, however, in this small series, up to 17% of patients required conversion to arthroplasty less than 10 years following the index microfracture procedure. Additional studies with larger patient cohorts are needed.