Purpose

Recently, various treatment methods for medial meniscus posterior root tear (MMPRT) have been introduced. Although fixation of the torn meniscus is an ideal method theoretically, the merits of fixation have been disputed. Arthroscopic meniscectomy and conservative treatment have also been considered as treatment options for MMPRT, especially in patient with mechanical symptoms. This study aimed to compare the clinical and radiological outcomes of arthroscopic meniscectomy and conservative treatment for degenerative MMPRT.

Material And Methods

From January 2007 to December 2014, 255 patients who were diagnosed with degenerative MMPRT with a minimum follow-up duration of 2 years were selected. Of the 255 patients, 148 underwent meniscectomy, and the remaining 107 underwent conservative treatment. After excluding patients who underwent meniscal repair or other ligament surgery, combined surgery, had a Kellgren-Lawrence (K-L) classification grade of > III, or >5° varus or valgus malalignment, 146 patients (Meniscectomy group, 90; Conservative group, 56) were finally evaluated. Clinical outcomes were assessed and compared between the two groups using the using the Visual Analog Scale (VAS), International Knee Documentation Committee (IKDC) subjective scoring scale, Tegner activity scale, and Lysholm knee scoring scale at the final follow-up. Regarding the radiological outcomes, we evaluated the progression of osteoarthritis (OA) according to the K-L classification of the medial compartment of the knee. We compared the hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), tibial posterior slope angle (TPSA), and width of medial joint space between the groups. After an average follow-up of 6.3 years, the survivorship was analyzed using the Kaplan–Meier method. The endpoint of survival was conversion to total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), or high tibial osteotomy (HTO) on the same knee.

Results

Although all clinical outcomes had significantly improved in both groups after treatment, the meniscectomy group did not show better improvement than the conservative group. The VAS score (p=0.07), IKDC subjective score (p=0.18), Tegner activity scale score (p=0.08), and Lysholm knee score (p=0.53) showed no significant differences between the two groups at the final follow-up. The progression of OA according to the K-L classification, HKAA and width of medial joint space was significantly advanced in the meniscectomy group (p=0.03, 0.04, 0.03, repectively). During the final follow-up, conversion to TKA, UKA, or HTO had occurred in six patients in the meniscectomy group and four patients in the conservative group; the difference was not significant (p=0.82). The 10-year survival rates in the meniscectomy and conservative groups were 87% and 88%, respectively.

Conclusions

This study demonstrated that both conservative treatment and meniscectomy provided symptomatic relief to patients with degenerative MMPRT without advanced OA and malalignment. However, it was confirmed that OA progression was more severe in the meniscectomy group than in the conservative group. The 10-year survival rates were not different between two groups. We conclude that arthroscopic meniscectomy had no advantage over conservative treatment in terms of clinical outcomes and OA progression.