Background: Arthroscopic narrow posteromedial gap of the knee may cause the failure of meniscus operation. The posteromedial complex (PMC) of the knee, including the posterior part of MCL and posterior oblique ligament, has a restrictive effect on the opening of the posteromedial gap of the knee in the half-extension position. Thus, we evaluated the radiological and clinical results of pie-crusting release of PMC for arthroscopic meniscal surgery in tight knees.
Methods : Sixty patients with posterior injury of the medial meniscus were reviewed. All patients accepted arthroscopic pie-crusting release of the PMC. Fourty patients accepted meniscoplasty, and 20 patients accepted meniscuc suturing. To evaluate the arthroscopic opening of the medial gap in 20°half-extension under 11-kg valgus stress, the width of the medial space before and after release were measured. During follow-up, the medial stability was evaluated by radiographic measurements of the joint space width (JSW) in 20°half-extension. MRI was conducted to evaluate the healing of MCL and meniscus. Knee functions were evaluated using VAS, Lysholm, IKDC and Tegner scoring systems.
Results: In all patients, meniscus operations were performed without iatrogenic cartilage injury. After PMC release, the arthroscopic width of the medial space was 5.7 ±0.5 mm, showing larger than that before release (2.5 ± 0.5 mm) (p < 0.01). The follow-up time was 21.93±7.04 months, there was no residual valgus laxity of the knee. The radiographic JSW was 5.97 ± 0.8 mm preoperatively, 9.2 ± 1.1 mm in the postoperative 1st week, and 6.1±0.9 mm in the postoperative 3rd months, showing no differences between pre- and postoperative 3rd month (p > 0.05). For sutured meniscus, MRI showed healing in 15 patients while five had two-grade abnormal signals. VAS, Lysholm, IKDC and Tegner scores were 1.80±0.51, 80.08±3.74, 82.17±4.64 and 5.48±0.59, respectively, showing significant differences compared with the preoperative scores (5.57±0.69, 48.17±4.22, 51.42±4.02 and 3.20±0.68, respectively) (P < 0.01).
Conclusion s: Pie-crusting release of PMC can increase the posteromedial space and improve the visual field of the knee under arthroscopy, and this technique do neither produce residual valgus instability of the knee nor affect clinical outcome at the final follow-up.