Total knee arthroplasty following lateral closing-wedge high tibial osteotomy versus primary total knee arthroplasty: a propensity score matching study

Abstract

Background: The disparity in patient-reported outcomes between total knee arthroplasty (TKA) following high tibial osteotomy (HTO) and primary TKA has yet to be fully comprehended. This study aims to compare the patient-reported outcomes, radiological parameters and complication rates between TKA following HTO and primary TKA.

Methods: Sixty-five patients who underwent TKA following lateral closing-wedge HTO were compared to a matched group of primary TKA at postoperative 6-months and 1-year. Between-group confounders of age, gender, smoking status, Body Mass index, preoperative Numeric Rating Scale (NRS) pain in rest, Knee injury and Osteoarthritis Outcome Score-Physical function Shortform (KOOS-PS), EuroQol five-dimensional (EQ-5D) overall health score, and Oxford Knee Score (OKS) were balanced by propensity score matching. Patient-reported outcome measures were NRS pain in rest, KOOS-PS, EQ-5D overall health score, and OKS. Radiological parameters were femorotibial angle, medial proximal tibial angle, anatomical lateral distal femoral angle, posterior tibial slope, and patellar height assessed by Insall-Salvati ratio. The complication rates of TKA were compared between the two groups. The HTO survival time, the choice of staple removal before or during TKA in patients who underwent TKA following HTO patients, and the rate of patellar resurfacing were assessed. The p value < 0.0125 indicates statistical significance after Bonferroni correction.

Results: After propensity score matching, no significant between-group differences in the patient-reported outcome measures, radiographical parameters and complication rates were found (p > 0.0125). In the TKA following HTO group, with an average HTO survival time of 8.7 years, staples were removed before TKA in 46 patients (71%) and during TKA in 19 patients, and 11 cases (17%) had patella resurfacing. In the primary TKA group, 15 cases (23%) had patella resurfacing.

Conclusion: The short-term assessment of TKA following HTO indicates outcomes similar to primary TKA. A previous HTO does not impact the early results of subsequent TKA, suggesting that the previous HTO has minimal influence on TKA outcomes.

Level of evidence: III, cohort study.

Keywords: High tibial osteotomy; Patient-reported outcomes; Propensity score match; Radiological results; Total knee arthroplasty.

Fig. 1

Radiographs taken before and after lateral closing-wedge HTO. HTO High tibial osteotomy. A Varus mechanical axis before HTO; B Valgus mechanical axis after HTO

Fig. 2

Total knee arthroplasty following lateral closing-wedge high tibial osteotomy. A Subcutaneous approach to the anterior compartment; B L-incision to the anterior compartment; C Release of the staples; D Closure after staples removal; E Medial approach for total knee arthroplasty

Fig. 3

Illustration of radiological measurements. A FTA Femoral-tibial angle; aLDFA anatomical lateral distal femoral angle; MPTA medial proximal tibial angle; B PTS posterior tibial slope; Patellar height via Insall-Salvati method: ratio of blue-line to red-line; C, D Total knee arthroplasty with Genesis II Posterior Stabilized implant and patellar resurfacing

Fig. 4

Patient selection process. TKA Total knee arthroplasty; HTO High tibial osteotomy; UKA uni-compartmental knee arthroplasty; BMI Body Mass Index; PROMs Patient-reported outcome measures. The PROMs are Numeric Rating Scale pain in rest, Knee injury and Osteoarthritis Outcome Score-Physical function Shortform (KOOS-PS), EuroQol 5 Dimension overall health score, and Oxford Knee Score