The influence of posterior tibial slope on the mid-term clinical effect of medial-pivot knee prosthesis

Weipeng Shi,Haining Zhang,Xuan Zhao,Tao Li,Yaping Jiang,Yingzhen Wang

doi:10.1186/s13018-021-02704-y

Abstract

ObjectiveTo evaluate the effect of posterior tibial slope (PTS) on the mid-term clinical outcome following a medial-pivot (MP) prosthesis.MethodTwo hundred thirty-three patients from The Affiliated Hospital of Qingdao University, who had undergone a total knee arthroplasty (TKA) with MP prosthesis between January 2015 and December 2015, were retrospectively included in this study. They were divided into 3 groups according to postoperative PTS: A ≤ 5°; B 5-7°; and C ≥ 7°. Multiple assessments were made on the patient postoperatively and recorded in the three groups, the measurements of this study included: the range of motion (ROM), knee scoring system (KSS), Western Ontario and McMaster universities osteoarthritis index (WOMAC), posterior condylar offset (PCO), joint line height, and postoperative complications.ResultsThe average post-operative ROM for groups B and C were 108° and 110° respectively; this was significantly higher than that of group A (98°, P < 0.001). The WOMAC scores of patients in group C were significantly lower than those in groups A and B (P < 0.05). However, there were no significant differences in KSS, PCO, and joint line height among the 3 groups (P > 0.05). Only 2 cases of postoperative complications occurred in group C, these were ameliorated after operation.ConclusionWith an increase to PTS, the postoperative ROM can be significantly increased for the patient. However, the knee joint function will not be significantly improved, and the stability of knee joint will not be affected when within the limits of appropriate PTS.

Highlights

Knee osteoarthritis (KOA) is a chronic disease involving the synovium and cartilage of the joints
There were no significant differences in knee scoring system (KSS), posterior condylar offset (PCO), and joint line height among the 3 groups (P > 0.05)
Exclusion criteria: (1) Patients suffering from neurological, psychiatric, and other systemic diseases, unable to cooperate with followup; (2) osteoarthritis of the knee combined with immunemediated comorbidities such as rheumatoid arthritis; (3) a previous history of knee surgery; (4) traumatic arthritis, due to a previous history of knee joint infection; (5) nonoperative causes after operation that lead to functional damage of the knee joint

Summary

Introduction

Knee osteoarthritis (KOA) is a chronic disease involving the synovium and cartilage of the joints. Knee range of motion (ROM) is an important factor for the evaluating the effectiveness of a TKA. The condyle can still achieve a normal roll-back motion during knee flexion movement; this means the prosthetic mimics a natural knee joint. Does this improve knee joint kinematics but it restores joint stability, joint deep flexion, and reduces wear on the polyethylene gaskets [7, 13]

Methods

Results

Discussion

Conclusion