gms | German Medical Science

Objectives: To demonstrate comparative KOOS Pain outcomes of an interpositional knee meniscus endoprosthesis versus non-surgical controls in treatment of persistent post meniscectomy knee pain.

Methods: 243 patients enrolled in a pooled population, randomized controlled trial (RCT) and single-arm study, comparing the investigational device to non-surgical standard of care. Of the first 100 patients enrolled, whose follow-up has exceeded 12 months, 65 patients were treated with the interpositional endoprosthesis device, and 35 were treated non-surgically (Table 1 [Tab. 1]). Validated KOOS scores at baseline, 6-week, 6-month, and 12-month time points were obtained from all patients where a „clinically significant improvement“ was considered to be an increase of 20 KOOS points, based on Roos et al., (2003). The investigational and control cohorts were compared at each time point using either a two tailed t-test or Fisher exact test. All baseline cohort comparisons of demographics and KOOS Pain were not statistically different (p>0.05).

Results and conclusion: Improvement in KOOS Pain for the investigational and control cohorts at 6-months and 12-months were 25.0 and 10.0 points, and 31.2 and 14.5 points, respectively (Figure 1 [Fig. 1]). These data show a statistically significant improvement, above the clinically meaningful threshold, in the investigational arm versus the control arm as early as 6 months (25.0 vs 10.0 pts) and continues through the 12-month timepoint. At 12 months, 3 (4.6%) investigational vs. 5 (14.3%) control patients were no longer qualified to remain in the study, and deemed study failures, due to removal of the investigational device, and due to non-surgical control patients requiring surgical intervention, respectively (Table 1). Adverse event analysis showed that at 12 months, more patients progressed to advanced knee reconstructive arthroplasty procedures in the non-surgical, control group (n=4, 11.4%) than in the surgical, investigational group (n=1, 1.5%). These early results of effectiveness using one outcome measurement (KOOS Pain) are encouraging. The investigational treatment showed statistically different outcomes, above the clinically important threshold, at 6 and 12 months compared to non-surgical controls. Further study of the clinical outcomes of these patients and their adverse events is ongoing, with long-term results of both the randomized controlled trial and the single-arm study to be reported in the future.