Medial Fixed Bearing UKR: Technique and Tips
Unicompartmental knee replacement (UKR) is an alternative to total knee replacement (TKR) in patients with end-stage knee osteoarthritis confined to one compartment (Liddle AD, Pandit H, Judge A, Murray DW, Liddle AD, Mrcs DP, et al. Optimal usage of unicompartmental knee arthroplasty: a study of 41 986 cases from the national joint registry for England and Wales. Bone Joint J [Internet]. 2015 [cited 2017 Aug 14];97:1506–11. Available from: http://bjj.boneandjoint.org.uk/content/jbjsbr/97-B/11/1506.full.pdf). Fixed bearing UKR has similar excellent outcomes and at least equivalent survivorship to the mobile-bearing implants without the risk of dislocation, allowing the surgeon to focus on balancing the gaps while ensuring slight under-correction. There are five key principles for performing fixed bearing UKR: (1) under-correction of limb alignment, (2) component to component alignment, (3) restoring tension to soft tissues, (4) posterior slope, and (5) component sizing. This technical guide describes the setup, exposure, tibial and femoral prep, and sizing and implanting technique plus technical tips based on the extensive experience of the senior authors, to ensure a reproducible result. Appropriate implant-specific training should be sought prior to undertaking UKR with an unfamiliar implant.
KeywordsFixed bearing unicompartmental knee replacement Surgical technique Fixed bearing unicompartmental knee arthroplasty Gap balancing Anteromedial osteoarthritis
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