Wide Variation in Methodology in Level I and II Studies on Cartilage Repair: A Systematic Review of Available Clinical Trials Comparing Patient Demographics, Treatment Means, and Outcomes Reporting

Abstract

Background: The management of complex cartilage pathology in young, otherwise healthy patients can be difficult.

Purpose: To determine the nature of the design, endpoints chosen, and rate at which the endpoints were met in published studies and ongoing clinical trials that investigate cartilage repair and restoration procedures.

Study design: Systematic review.

Methods: A systematic review of the publicly available level I/II literature and of the publicly listed clinical trials regarding cartilage repair and restoration procedures for the knee was conducted adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: Seventeen published studies and 52 clinical trials were included. Within the 17 published studies, the most common procedure studied was microfracture (MFX) + augmentation (N = 5; 29.4%) and the most common comparison/control group was MFX (N = 10; 58.8%). In total, 13 different cartilage procedure groups were evaluated. For published studies, the most common patient-reported outcome (PRO) measures assessed is the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Visual Analog Scale-Pain (VAS) (N = 10 studies, 58.8% each, respectively). Overall, there are 10 different PROs used among the included studies. Ten studies demonstrate superiority, 5 demonstrate noninferiority, and 2 demonstrate inferiority to the comparison or control groups. For the clinical trials included, the most common procedure studied is MFX + augmentation (N = 16; 30.8%). The most common PRO assessed is KOOS (N = 36 trials; 69.2%), and overall there are 24 different PROs used among the included studies.

Conclusions: Recently published studies and clinical trials evaluate a variety of cartilage repair and restoration strategies for the knee, most commonly MFX + augmentation, at various time points of outcome evaluation, with KOOS and VAS scores being used most commonly. MFX remains the most common comparison group for these therapeutic investigations. Most studies demonstrate superiority versus comparison or control groups. Understanding the nature of published and ongoing clinical trials will be helpful in the investigation of emerging technologies required to navigate the regulatory process while studying a relatively narrow population of patients.

Keywords: articular cartilage; articular cartilage resurfacing; clinical trial; knee; patient-reported outcomes.

Figure 1.

Search algorithm used to identify and screen studies to be included in the review of published literature.

Figure 2.

Search algorithm used to identify and screen trials to be included in the review of publicly listed clinical trials.

Figure 3.

Frequency among included studies of time point inclusion in follow-up. Note: Total frequency values add up to greater than the number of studies as multiple studies had >1 time point for evaluation.

Figure 4.

Number of time points for patient evaluation in each individual study.

Figure 5.

Patient-reported outcome meaures reported by each included study. KOOS = Knee Injury and Osteoarthritis Outcome Score; VAS = visual analog scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index Score; IKDC = International Knee Documentation Committee; SF = Short Form.

Figure 6.

Frequency among included clinical trials of time point inclusion in follow-up. Note: Total frequency values add up to greater than the number of studies as multiple studies had >1 time point for evaluation.

Figure 7.

Number of time points for patient evaluation in each individual clinical trial. Pts = points.

Figure 8.

Patient-reported outcome measures reported by each included clinical trial. KOOS = Knee Injury and Osteoarthritis Outcome Score; VAS = visual analog scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index Score; IKDC = International Knee Documentation Committee score; SF = Short Form; QoL = quality of life; ADL = activities of daily living; VR = Veterans RAND.