Long-term Results of Hybrid Total Knee Arthroplasty: Minimum 10-years Follow-up

Abstract

Purpose: To evaluate the survival rate and long term clinical outcomes of hybrid total knee arthroplasty (TKA).

Materials and methods: We retrospectively analyzed 113 hybrid TKAs (NexGen) in 86 patients that were followed for more than 10 years. Kaplan-Meier survival curves were generated using revision as an end point. Knee Society Score (KSS) and range of motion were evaluated for clinical assessment and plane radiographs were used to evaluate implant problems.

Results: At 11.2 years (range, 10 to 12.2 years) of follow-up on average, 7 knees required revision. The reason for revision was aseptic loosening in 4 knees (1 in femoral and tibial component and 3 in tibial component only) and infection in 3 knees. The survival rate was 93.8% at 12 years for all knees, and 96.5% when septic loosening was excluded. The KSS improved from 29.3 to 91.5 in the Cruciate-Retaining type (CR) and from 21.5 to 90.3 in the posterior stabilizing type (PS) at latest follow-up. The average range of motion was improved from 120.6° to 133.8° in the CR type and 119.5° to 135.5° in the PS type.

Conclusions: Hybrid TKA provides good survival rates and clinical results comparable to cemented TKA.

Keywords: Hybrid; Long term follow-up; Survival rate; Total knee arthroplasty.

Fig. 1

A 65-year-old female who had undergone total knee arthroplasty on both knees. (A) Preoperative anteroposterior and lateral radiographs show osteoarthritic changes. (B) The cruciate retaining type implant in the right knee and posterior stabilizing type in the left knee were inserted. After 12 years, the radiographs show no loosening on both components. (C) After 12 years, the full-flexion film shows excellent flexion on both knees.

Fig. 2

A 57-year-old female has been performed cruciate retaining-type total knee arthroplasty on the left knee. (A) Six years after the operation, the radiograph shows loosening of the tibial component. (B) Revision arthroplasty was performed. (C) Five years after the revision arthroplasty, the radiograph shows no loosening of the prosthesis.

Fig. 3

Kaplan-Meier survival curves were generated: (A) Including Infection. (B) Excluding Infection. CR: cruciate retaining, PS: posterior stabilizing.