Safety and early results of Subchondroplasty® for the treatment of bone marrow lesions in osteoarthritis: a systematic review

Abstract

Purpose: Subchondroplasty® is a novel minimally invasive procedure for painful subchondral bone marrow lesions (BMLs). The aim of this systematic review was to characterize the clinical outcomes of the Subchondroplasty® procedure, a novel minimally invasive procedure for the treatment of BMLs. The hypothesis tested was that patients experience improvements in pain and functional outcomes following the Subchondroplasty® procedure.

Methods: MEDLINE, Embase, Web of Science, and Clinicaltrials.gov were searched from database inception to search date (June 10, 2020) for all clinical studies which discussed Subchondroplasty®. Two reviewers independently screened 45 unique results and 17 studies were included in the final analysis. Data were collected regarding patient demographics, indications, pain, functional scores, conversion to TKA, and complications of the procedure.

Results: All but one study were level IV evidence; the mean MINORS score was 9 ± 2. There were 756 patients included, 45.1% were female, and the mean age was 54 years (range 20-85). Thirteen studies investigated the effect Subchondroplasty® to the knee, while four studied the impact on the foot and ankle. Median length of follow-up was 12 months. The most common indication for Subchondroplasty® was joint pain with corresponding BML. Major contraindications to Subchondroplasty® included severe OA, joint instability, and malalignment. Mean pain score on visual analogue scale (VAS) prior to Subchondroplasty® was 7.8 ± 0.6, but decreased to 3.4 ± 0.7 postoperatively. All studies investigating functional scores reported improvement following Subchondroplasty® (IKDC 31.7 ± 1.9-54.0 ± 4.2 and KOOS 38.1 ± 0.6-70.0 ± 4.1). There were consistently high levels of patient satisfaction; 87 ± 8% of patients would be willing to undergo the procedure again. Seven cases of complications were reported, most seriously osteomyelitis and avascular necrosis. Conversion to knee arthroplasty ranged from 12.5 to 30% with length of follow-up ranging from 10 months to 7 years.

Conclusions: Existing low-quality studies show Subchondroplasty® to benefit patients with BMLs through reduction in pain and improvement in function, along with a high degree of satisfaction following the procedure. The low short-to-medium term conversion rate to arthroplasty suggests that Subchondroplasty® may play a role in delaying more invasive and expensive procedures in patients with BMLs. Subchondroplasty® is a novel procedure that has promising initial findings, but requires further high-quality, comparative studies with long-term follow-up to better understand the outcomes of the procedure and impact clinical practice recommendations.

Level of evidence: Systematic Review of Level III and IV Studies, Level IV.

Keywords: Bone marrow lesions; Calcium phosphate; Osteoarthritis; Subchondroplasty®.