Efficacy Analysis of Arthroscopic Treatment of Synovial Chondromatosis of the Knee: A Retrospective Study of More Than Five Years

Abstract

Objective: The synovial chondromatosis is an exceptionally rare benign condition, predominantly found in the knee joint, and can result in pain, restricted mobility, and potential irreversible damage to the joint and cartilage. Despite the utilization of arthroscopic techniques in the surgical management of synovial chondromatosis, there remains a paucity of long-term assessment regarding its efficacy. The main objectives of this study include: (i) investigating the long-term efficacy of arthroscopic surgery in patients with knee synovial chondromatosis;(ii) identifying factors influencing functional improvement in patients post-surgery function.

Methods: We conducted a retrospective analysis of all patients with synovial chondromatosis of the knee who underwent arthroscopic synovectomy and loose body removal at our institution between June 2009 and January 2020. The follow-up period for all cases exceeded 5 years. Data collection included demographic details, clinical efficacy indicators(VAS, KOOS, WOMAC, etc.), imaging findings, and subjective satisfaction of patients with surgical outcomes. Data analysis selected t-tests, ANOVA, non-parametric tests, and correlation methods based on normality test results.

Results: We enrolled a total of 13 patients, including 4 men and 9 women, with a mean follow-up of 113.15 ± 30.45 months (range 61-145). There were no postoperative complications, recurrence, or malignant transformation in all patients, and the VAS scores, KOOS scores, WOMAC scores, and Lysholm scores of all patients were significantly improved at 3 months, 6 months, 1 year, 5 years, and the last follow-up (p < 0.05). However, one patient experienced osteoarthritis progression, necessitating arthroplasty.

Conclusion: This retrospective study demonstrated that arthroscopic treatment for knee synovial chondromatosis is effective and safe. It leads to immediate post-intervention improvement in symptoms and function, with sustained long-term benefits.

Keywords: arthroscopy; clinical efficacy outcomes; long‐term outcome; osteoarthritis; synovial chondromatosis.

FIGURE 1

The inclusion and exclusion process for patients.

FIGURE 2

The patient is a 36‐year‐old female who presented with pain and discomfort in her right knee for over 8 years, which had worsened in the past 2 months. Physical examination revealed significant swelling of the right knee, mild tenderness, notable patellar crepitus, and a palpable mass in the suprapatellar pouch. During surgery, extensive hyperemia and thickening of the synovium were observed. Multiple large, smooth synovial chondromatosis nodules of varying sizes were removed from the suprapatellar pouch. Additionally, several broad bean‐sized loose bodies were found in the upper part of the suprapatellar pouch, the posterolateral compartment, and the intercondylar fossa. Pathological examination showed synovial tissue hyperplasia with calcification. Postoperatively, the patient's symptoms improved significantly, and her function recovered well. (A) The patient's MRI shows multiple loose bodies within the knee joint; (B) the patient's X‐ray reveals knee synovial chondromatosis and osteoarthritis; (C) the patient's X‐ray at the last follow‐up. The yellow arrows indicate the loose bodies in the suprapatellar pouch of the knee.

FIGURE 3

The patient is a 53‐year‐old male who presented with left knee pain accompanied by locking for 6 years. Physical examination revealed tenderness in the left knee, significant patellar crepitus, and marked limitation of movement. During surgery, mild synovial hyperplasia was observed, along with obvious degeneration of the articular cartilage on the femoral condyles and patella. Several hard, variably sized loose bodies were found within the joint space. Pathological examination showed bone/cartilage components consistent with synovial chondromatosis. Postoperatively, the patient's symptoms improved significantly, and his function recovered well. (A) The patient's MRI shows multiple loose bodies within the knee joint; (B) the patient's X‐ray reveals secondary osteoarthritis in the knee joint, with significant osteophyte formation in the patellofemoral joint; (C) the patient's X‐ray at the last follow‐up. The yellow arrows indicate the loose bodies in the suprapatellar pouch of the knee, and the white circles mark the osteophytes.

FIGURE 4

(A) Changes in VAS scores of patients; (B) changes in KOOS score of patients; (C) changes in WOMAC score of patients; (D) changes in Lysholm Knee Score of patients. KOOS: Knee Injury and Osteoarthritis Outcome Score; VAS: visual analog scale; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index Scale.