LYSHOLM SCORES AND TEGNER INDEX TO ASSESS FUNCTION AND RETURN TO ACTIVITY OUTCOMES SIX YEARS AFTER PARTIAL MENISCECTOMY VS COLLAGEN MENISCUS IMPLANTS

Abstract

Objective: Lysholm and Tegner scores have been validated to assess outcomes of meniscus surgery. We prospectively determined Lysholm scores for function and calculated Tegner index to determine percentage of pre-injury activity level regained by patients six years after partial meniscectomy alone versus placement of collagen meniscus implants (CMI, MenaflexTM). We hypothesized that in this prospective randomized multicenter clinical trial, patients who received collagen meniscus implant would have better function and would have regained more of their lost activity than patients with meniscectomy alone.

Methods: Patients 18 to 60 years old who had undergone 1 to 3 prior partial medial meniscectomies (thus deemed “chronic”) and remained symptomatic randomly received either a CMI (n=76) or another partial medial meniscectomy (control) (n=69). Lysholm and Tegner data were collected prospectively. Tegner index was calculated by subtracting preoperative Tegner scores from the longest follow-up scores and then dividing that difference by the difference of pre-injury less preoperative scores. The quotient multiplied by 100 yields a percentage that represents amount of lost activity regained as a result of therapeutic intervention. The findings were then compared to earlier analyses of the same patients.

Results: Average follow-up for both groups was 72 months (range for CMI, 24 to 88; for controls, 24 to 92). For both groups, Lysholm scores improved significantly (p=0.0001) from preoperative to 6 years postoperative, but there was no difference between treatments. Average Tegner index for CMI patients was 0.47; thus, 6 years after receiving CMI they had regained 47% of activity lost due to the inciting injury. Average Tegner index for controls was 0.22; thus, they regained 22% of lost activity. This difference was clinically and statistically significant (p=0.028). The Lysholm scores for both groups were unchanged from 2-year findings; however, Tegner index for CMI patients improved from 0.42 to 0.47, but Tegner index decreased for controls from 0.29 earlier to 0.22 at 6 years.

Conclusion: CMI (Menaflex) and partial meniscectomy both allowed chronic patients to regain function equally 6 years after index surgery. However, patients treated with CMI had significantly higher Tegner index at 6 years compared to controls, thus chronic CMI patients regained more of the activity they had lost as a result of their inciting injury. Noteworthy, CMI patients continued to gain activity from 2 to 6 years while meniscectomy only controls lost activity. These findings suggest that control patients reduced their activity levels in an attempt to maintain their function.