Does Isolated Meniscectomy Alter The Alignment Of Lower Limbs? A Systematic Review And Meta-analysis

Background:In existing research,whether meniscal surgery alter the alignment of lower limbs are controversial.Studies have reported the lower limb alignment would change after meniscectomy,whereas others reported no significant change.Purpose:To determine whether alignment of lower limbs would change after meniscectomy.Study design:Systematic review and meta-analysis.Methods:We comprehensively searched PubMed,Web of Knowledge,and the Cochrane Library and performed a systematic review and meta-analysis of randomized controlled trials(RCTs),cohort studies,case-control studies and case-series which reported the exact values of alignment change.Results:The result of alignment changes between and after surgery in a total of 11 groups including 627 patients showed that meniscectomy would alter the alignment of lower limbs to a different degree.There was no significant change in alignment of lower limbs during partial resection of the lateral normal shaperd meniscus tear(ES=0.33 CI:-1.34-1.99);The alignment change may have a varus trend after medial meniscectomy(ES=I.16 CI:0.14--2.19),the significant varus trend was found when the total medial meniscus was removed(ES=2.30 CI:1.73--2.87),but not significantly changed when the medial meniscus was partially resected(ES=0.65 CI:0.08--1.23);When the lateral discoid meniscus is removed,the alignment showed a valgus tendency(ES=-1.65 CI:-2.75---0.55),and the valgus trend of alignment will be more obvious when the total discoid meniscus removed(ES=-3.12 CI:-3.71---2.53),but this trend was smaller when the lateral discoid meniscus was partially removed(ES=-1.29 CI:-2.57---0.01).Conclusions:Arthroscopic meniscectomy has different degrees of influence on the alignment of lower limbs.Partial meniscectomy of the normal shaped lateral meniscus has little effect on the alignment.Medial meniscectomy may cause varus trend on the alignment,this trend is more obvious during complete resection.However,there is no significant change in the alignment when the medial meniscus is partially removed.Patients with discoid lateral meniscus may have larger valgus trend during partial meniscectomy and total meniscectomy,with a larger angle of valgus during meniscus complete resection.Degeneration of the knee joint should be closely related to the disappearance of the physiological function of the meniscus after meniscectomy.Therefore,the change of preoperative alignment and postoperative alignment has no significant effect on the clinical effect after meniscectomy,but the surgeon should pay attention to retain the meniscus as much as possible to prevent knee degeneration.