Limb position influences component orientation in Oxford mobile bearing unicompartmental knee arthroplasty

Abstract

Aims The mobile bearing Oxford unicompartmental knee arthroplasty (OUKA) is recommended to be performed with the leg in the hanging leg (HL) position, and the thigh placed in a stirrup. This comparative cadaveric study assesses implant positioning and intraoperative kinematics of OUKA implanted either in the HL position or in the supine leg (SL) position. Methods A total of 16 fresh-frozen knees in eight human cadavers, without macroscopic anatomical defects, were selected. The knees from each cadaver were randomized to have the OUKA implanted in the HL or SL position. Results Tibial base plate rotation was significantly more variable in the SL group with 75% of tibiae mal-rotated. Multivariate analysis of navigation data found no difference based on all kinematic parameters across the range of motion (ROM). However, area under the curve analysis showed that knees placed in the HL position had much smaller differences between the pre- and post-surgery conditions for kinematics mean values across the entire ROM. Conclusion The sagittal tibia cut, not dependent on standard instrumentation, determines the tibial component rotation. The HL position improves accuracy of this step compared to the SL position, probably due to better visuospatial orientation of the hip and knee to the surgeon. The HL position is better for replicating native kinematics of the knee as shown by the area under the curve analysis. In the supine knee position, care must be taken during the sagittal tibia cut, while checking flexion balance and when sizing the tibial component.

The risk of tibial eminence avulsion fracture with bi-unicondylar knee arthroplasty

“…A recent study determined that surgical cut errors in UKA-M were effected by limb posture. 43 They found similar errors to those used in this study, however they found significantly higher errors in the internal rotation of the medial component when the traditional supine leg position was used, rather than the manufacturer-recommended hanging leg position. The extreme of the internal rotation error associated with the supine position was greater than the error assessed in this study.…”

Spinal Versus General Anesthesia for the Outpatient Unicompartmental Knee Arthroplasty: A Randomized Controlled Trial

“…The inclusion criteria were as follows: (1) After approved by the Ethics Committee of our institution (KY2020124) , a randomized controlled trial was conducted on the basis of pre-and postoperative outpatient clinical charts. From October 2017 to June 2018, 64 consecutive and unselected patients who underwent primary, medial UKA in our institution were involved in our study.…”

“…Unicompartmental knee arthroplasty (UKA) is a safe and effective intervention for end-stage knee arthritis con ned to the medial compartment [1] [2]. Compared with total knee arthroplasty (TKA), preservation of cruciate ligaments and less bone loss allowed UKA to attain a earlier recovery, less perioperative complications, and a better range of motion(ROM) of knee [3] [4].…”

Model Properties and Clinical Application in the Finite Element Analysis of Knee Joint: A Review

“…The advantage of cadaveric research is that it is more intuitive; however, it is not helpful for in-depth research. [1][2][3] First, it is difficult and expensive to obtain cadaveric specimens. Second, large joints are challenging to preserve, significantly limiting intact joint research.…”

“…To better understand the knee joint's function and disease mechanism, many biomechanical studies have been carried out based on cadaveric specimens. The advantage of cadaveric research is that it is more intuitive; however, it is not helpful for in‐depth research 1–3 . First, it is difficult and expensive to obtain cadaveric specimens.…”