Increased risk of reoperation and failure to attain clinically relevant improvement following autologous chondrocyte implantation of the knee in female patients and individuals with previous surgeries: a time‐to‐event analysis based on the German cartilage registry (KnorpelRegister DGOU)

Abstract

Purpose This study aimed to analyze the risk of reoperation following autologous chondrocyte implantation (ACI) of the knee utilizing third-generation ACI products in a time-to-event analysis and report on the associated patient-reported outcome measures (PROM) in case of reoperation. Methods Patients undergoing ACI were included from a longitudinal database. Patient age, sex, body mass index (BMI), number of previous surgeries, lesion localization, lesion size, symptom duration, as well as time and type of reoperation was extracted. A cox proportional-hazards model was applied to investigate the influence of baseline variables on risk of reoperation. Reoperation was defined as any type of subsequent ipsilateral knee surgery, excluding hardware removal. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was utilized to compare PROM between patients with and without reoperation. Results A total of 2039 patients were included with 1359 (66.7%) having a minimum follow-up of 24 months. There were overall 243 reoperations (prevalence 17.9%). Minor arthroscopic procedures (n = 96, 39.5%) and revision cartilage repair procedures (n = 78, 32.1%) were the most common reoperations. Nineteen patients (0.9%) reported conversion arthroplasty at 17.7 (10.4) months after ACI. Female sex (HR 1.5, 95% CI [1.2, 2.0], p = 0.002) and the presence of 1–2 previous surgeries (HR 1.5, 95% CI [1.1, 2.0], p = 0.010), or more than 2 previous surgeries (HR 1.9, 95% CI [1.2, 2.9], p = 0.004) were significantly associated with increased risk of reoperation following ACI. Significantly less patients surpassed the minimal clinically important difference (MCID) in the reoperation group at 24 months regarding the KOOS subscores pain (OR 1.6, 95% CI [1.1, 2.2]), quality of life (OR 2.2, 95% CI [1.6, 3.2]), symptoms (OR 2.0 [1.4, 2.9]), and sports (OR 2.0 [1.4, 2.8]). Conclusion Female patients and individuals with a history of previous surgeries face an elevated risk of requiring reoperation after undergoing ACI, which is associated with failure to attain clinically relevant improvements. A thorough evaluation of the indications for ACI is paramount, particularly when patients have a history of previous surgeries. Level of evidence Level III.

Specific lipid magnetic sphere sorted CD146-positive bone marrow mesenchymal stem cells can better promote articular cartilage damage repair

“…Although autologous chondrocyte transplantation has shown good results in prospective randomized trials, there are some problems, including the need for two surgeries and high treatment costs [ 33 ]. Osteochondral grafting has favorable short-term results, but the failure rate of osteochondral grafting is significantly higher at 10 years after surgery compared with autologous chondrocyte grafting [ 34 ]. Microfractures have better short-term symptomatic improvement, but fibrous tissue regeneration is seen at 2 years postoperatively and there is a recurrence of clinical symptoms [ 35 ].…”