Methodologic quality of knee articular cartilage studies.

PURPOSE: (1) To evaluate the quality of knee articular cartilage surgery literature using established methodologic quality instruments, and (2) to assess whether study quality has improved with time.

METHODS

A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies of autologous chondrocyte implantation (ACI), osteochondral autograft and allograft transplant, and microfracture were analyzed. Study methodologic quality was assessed by the level of evidence and 9 different methodologic quality questionnaires. Comparisons were made between different surgical technique groups by use of Student's t tests. Assessment of study quality improvement with time was performed by comparison of the Coleman Methodology Score (CMS) from the included studies (2004 to present) and CMS from a prior study assessing quality of articular cartilage studies (1985 to 2004). Furthermore, assessment of study quality improvement with time was performed over the period of the included studies (2004 to present).

RESULTS

We included 194 studies (11,787 subjects). Most evidence was Level IV (76%) and nonrandomized (91%). ACI was the most commonly reported technique (62% of studies). Only 34% of studies denied the presence of a financial conflict of interest. The mean subject age was 33.5 ± 8.2 years, and the mean length of follow-up was 3.7 ± 2.3 years. By use of study quality questionnaires, the methodologic quality of articular cartilage studies was poor. However, study quality (after 2004) was significantly improved versus that reported from a prior study (before 2004) using the CMS (P < .01). The mean level of evidence, CMS, CONSORT (Consolidated Standards of Reporting Trials) score, and Jadad score showed no significant improvement over the period of the included studies (P > .05). The quality of randomized controlled trials (RCTs) was significantly higher than that of non-RCTs (P < .05). The most common study weaknesses included blinding, subject selection process, study type, sample size calculation, and outcome measures and assessment.

CONCLUSIONS

The methodologic quality of knee articular cartilage surgery studies was poor overall and also for individual techniques (ACI, osteochondral autograft transplant, osteochondral allograft transplant, and microfracture). However, the overall quality of the investigations in this review (after June 2004) has significantly improved in comparison to those published before 2004. The quality of RCTs was significantly higher than that of non-RCTs. Level of evidence, CMS, CONSORT score, and Jadad score did not significantly improve with later publication date within the period of the studies analyzed. Methodologic quality deficiencies identified in this investigation may be used to guide future articular cartilage studies' design, conduct, and reporting.

LEVEL OF EVIDENCE: Level IV, systematic review of studies with Levels of Evidence I-IV.