TMJ synovial chondromatosis - an evaluation of 37 patients.

Purpose: The authors evaluated a cohort of 37 patients with histologically verified synovial chondromatosis (SC) between 2013 and 2022.

Methods: The cohort consisted of 37 patients (26 women, 11 men). 36 patients had unilateral involvement, while one patient had bilateral involvement. The average age of the patients was 54.77 years. The authors used the Milgram histopathological classification. They evaluated SC localisation, clinical symptoms, diagnostics and treatment (including recurrence incidence) in this cohort.

Results: In 31 patients (83.7%) SC affected only the upper joint space in one patient (2.7%) the lower space, and in five patients (13.6%) both spaces. 12 patients (32%) were Milgram Stage 1 (presence of synovial metaplasia without loose bodies), eight patients (22%) were Stage 2 (presence of synovial changes, loose bodies), and 17 patients (46%) were Stage 3 (presence of loose bodies, no synovial changes). Pain was the dominant clinical symptom (32 patients, 86.4%). Treatment consisted of arthroscopy and open surgery. Two patients underwent primary reconstruction and total TMJ replacement. Treatment was successful in 89.2% of cases (33 patients), with four (10.8%) patients suffering recurrence.

Conclusion: As this patient cohort shows, pain was the dominant symptom in patients with SC. Magnetic resonance imaging is fundamental in the diagnosis of SC, demonstrating pathological findings even in patients for whom an initial X-ray was negative. These were mainly patients with Milgram Stages 1 and 2 without calcification, loose bodies or pathological changes of the bone structures. This is why the authors recommend MRI for any patient experiencing pain for more than three months, and if this reveals an effusion, joint distension or intraarticular soft tissue mass, they will always indicate arthroscopy. Thorough follow-up of patients is recommended, although SC recurrence is not very frequent. The authors recommend follow-up one, three and six months after surgery, and then annually for the first five years after surgery. They recommend follow-up MRI one, two and five years after surgery.