Does medial collateral ligament pie-crusting induce residual laxity in arthroscopic management of medial meniscus tears? A prospective study of 40 cases.

INTRODUCTION: Arthroscopic meniscectomy and medial meniscal repair are frequent procedures, liable to be complicated by iatrogenic cartilage lesions, especially in tight knee. Medial collateral ligament pie-crusting was developed to counter this, but, although the technique is employed, its impact on medial laxity has not been precisely determined. We therefore conducted a prospective observational study to compare radiographic laxity preoperatively versus 6 weeks following pie-crusting.

HYPOTHESIS: Medial collateral ligament pie-crusting alters radiographic laxity at 6 weeks.

MATERIAL AND METHODS: Between December 2015 and February 2017, 40 patients (33 male, 7 female) underwent surgery with pie-crusting for isolated medial meniscal lesion. Mean age was 39 years (range, 20-54 years). Meniscectomy was performed in 33 cases (82.5%) and repair in 7 (17.5%). Pie-crusting used an intramuscular needle under arthroscopic control, adjacent to the medial meniscus at the posterior two-thirds junction of the compartment, until opening was deemed satisfactory. Laxity was compared on preoperative versus 6 weeks stress valgus views (Telos ™), by 2 independent observers, on 2 measurements: opening angle, and medial tibiofemoral joint space height. Each measurement was taken twice at a 2-week interval by each observer.

RESULTS: Inter- and intra-observer concordance was excellent on both measurements: intraclass correlation coefficient was 0.82 (95% CI, 0.73-0.89) and 0.91 (95% CI, 0.86-0.94) pre- and post-operatively for opening angle, and 0.87 (95% CI, 0.79-0.92) and 0.88 (95% CI, 0.82-0.92) for joint space height. Tibiofemoral joint space opening was significantly greater at 6 weeks on both measurements: 0.9±1° [range, -1° to 4°] (p<0.0001) and 1.1±1mm [range, -0.6 to 3.2mm] (p<0.0001).

DISCUSSION: Medial collateral ligament pie-crusting led to a moderate but significant increase in medial laxity at 6 weeks. A longer-term study is needed to assess progression.

LEVEL OF EVIDENCE: IV, prospective study without control group.