Unicompartmental knee replacement after high tibial osteotomy: Invalidating a contraindication

Area of Science:

• Orthopedic surgery
• Knee arthroplasty
• Biomechanics

Background:

• High tibial osteotomy (HTO) is a common procedure for knee osteoarthritis, but outcomes can decline over time.
• Revision surgery may be necessary after HTO, leading to comparisons between different reconstructive options.

Purpose of the Study:

• To compare clinical and radiological outcomes of unicompartmental knee replacement (UKR) and total knee replacement (TKR) in patients with a history of HTO.
• To compare these outcomes against primary UKR in knees without prior HTO.

Main Methods:

• Retrospective study of 63 patients (63 knees) divided into three groups: UKR after HTO (Group A), TKR after HTO (Group B), and primary UKR (Group C).
• Clinical outcomes assessed using Oxford Knee Score (OKS) and Knee Society Score (KSS) (knee and function).
• Radiological assessment included hip-knee-ankle angle, mechanical axis, and patellar height, evaluated pre- and post-operatively.

Main Results:

• No significant differences in OKS or KSS scores were observed between the three groups at a mean follow-up of 64 months.
• Radiological results were comparable across groups, with the exception of patellar height.
• A higher incidence of patella infra was noted in patients who had undergone prior HTO (Groups A and B).

Conclusions:

• Both UKR and TKR provide comparable clinical outcomes following HTO, similar to primary UKR.
• Prior HTO is associated with an increased risk of patellar height issues (patella infra) in subsequent knee replacement surgery.