Total knee arthroplasty in a patient with an ankylosing knee after previous patellectomy

Acceptable Functional Outcomes and Patient Satisfaction Following Total Knee Arthroplasty in Asians with Severe Knee Stiffness: A Matched Analysis

Background

This study evaluated outcomes following total knee arthroplasty for severely stiff knees in Asians.

Methods

Registry data of patients undergoing primary total knee arthroplasty between 2004 and 2013 were collected and retrospectively reviewed. Sociodemographic and anthropometric data together with the Oxford Knee Score and the Knee Society Score (Knee Society Knee Score and the Knee Society Function Score) were collected both preoperatively and postoperatively for up to 2 years. Case subjects consisted of patients with a preoperative flexion range of ≤ 20°. Control subjects consisted of patients with a preoperative flexion range of > 90°. Patients were matched for age, sex, and all preoperative scores in a 2:1 fashion. Two-year outcomes and 5-year revision rates were then compared between cases and controls.

Results

There were 28 cases and 56 controls. Cases had a significantly lower body mass index than the controls (p = 0.003) and had a longer hospital stay (p < 0.0001). At 2 years, cases had a significantly lower flexion range (p < 0.001) and a lower Knee Society Function Score (p = 0.020) than the controls. Cases had a significantly greater improvement in the flexion range (p < 0.001) postoperatively than controls. The mean change in functional outcomes at 2 years was comparable between the two groups. Seventy-one percent of the cases and 88% of controls were satisfied. There was a significant difference in the 5-year revision rate (10% vs 0%, p = 0.013). More cases were discharged to a rehabilitation facility compared to controls (p = 0.011). There were no differences in inpatient complication rates.

Conclusions

Functional outcomes and patient satisfaction were acceptable following total knee arthroplasty in Asian patients with severe knee stiffness.

Total knee arthroplasty conversion for patients with ankylosed knees

INTRODUCTION

The purpose of this study was to evaluate the results of total knee arthroplasty for patients with ankylosed knees.

METHODS

We evaluated seven patients (10 knees) who underwent total knee arthroplasties for ankylosed knees from 1995 to 2008. There were two men and five women, with a mean age of 44.1 years (42-48 years). The mean follow-up period was 10.2 years (1-19.5 years). A rectus snip was performed in all cases, and V-Y quadricepsplasty was used in one case of severe quadriceps contracture. In all cases, we used the PFC Sigma PS fixed model (DePuy Orthopaedics Inc., Warsaw, Indiana, USA). The goal was more than 90° of flexion. Clinical evaluation was performed using range of motion (ROM), Knee Society (KS) Knee Score, KS Function Score, and complications. Radiographs were used to evaluate loosening or osteolysis.

RESULTS

The ROF was improved from 9.5° (0-30°) to 78.5° (15-115°), The Knee Score improved from 42.6 (25-70) to 68.6 (41-97), and the Function Score improved from 39 (0-60) to 66 (40-90). A radiolucent line was detected in two cases (one patient) around the tibial component, and one case had a necrosis of skin edge. Only one case had no improvement of motion.

CONCLUSION

Total knee arthroplasty conversion for patients with ankylosed knees can achieve good results for motion and function without osteotomy of the tibial tuberosity when there is good quality soft tissue of the thigh.