Osteochondritis Dissecans of the Glenoid : an Analysis of Grades, Treatment and Outcomes

Abstract Background Osteochondritis dissecans (OCD) is an idiopathic disorder of subchondral bone that causes focal articular cartilage disruption with the potential long-term consequence of premature osteoarthritis. Glenoid OCD is exceedingly rare. This case series aims to identify the grades of glenoid OCD, and report its grade-specific treatment with clinical, radiological, and functional outcomes. Methods Prospectively collected data of consecutive patients diagnosed with a symptomatic glenoid OCD, who had a minimum two-year follow-up, following non-operative or surgical treatment, was retrospectively analyzed. Osteochondral defects secondary to acute trauma, instability, and primary osteoarthritis were excluded. Pre-treatment and post-treatment clinical, radiological, and sports participation data was collected. This included pre-treatment MRI for grading of glenoid OCD according to the International Cartilage Research Society (ICRS) OCD staging system, and postoperative MRI for grading of articular cartilage repair using the MOCART (MRI observation of cartilage repair tissue) scoring system. Results The study identified 7 competitive overhead athletes with symptomatic unilateral glenoid OCD, with a post-treatment minimum two-year follow-up. Of 4 patients with ICRS OCD I, 3 healed with non-operative treatment, whereas 1 progressed to ICRS OCD II. This patient along with another 3 patients with unstable glenoid OCD underwent arthroscopic OCD excision with bone marrow stimulation (BMS) cartilage repair. All patients improved following treatment and had full passive and active range of shoulder movements, with normal strength and stability at the 2- year follow-up. The mean MOCART score on MRI at 2 years for the 4 patients who underwent surgery was 82.5 (range, 75-90). MRI documented healing in all 3 patients with ICRS OCD I who underwent non-operative treatment. All patients returned to the same or higher level of sport following treatment, with mean time to return to sports being 8.0 months (range, 6-11 months) for non-operative treatment, and 6.8 months (range, 5-10 months) for operative treatment. This difference was not statistically significant (p value 0.55). No patient had recurrence of symptoms till latest follow-up. Conclusion Despite the glenoid being a concave non-weight bearing articular surface, OCD at this site has pathological grades similar to other convex weight-bearing articular surfaces. Notwithstanding the limited number of cases, it would appear that ICRS OCD I can often be successfully treated with non-operative treatment, whereas ICRS OCD II, III, IV, warrant operative treatment. BMS is a safe and predictable option for glenoid OCD cartilage repair and allows athletes a quick and successful return to sports.