Our unit historically performed total hip replacement (THR) through either posterior or anterolateral approaches. In November 2020 a group of 5 consultants transitioned to utilising the Direct Anterior Approach (DAA). Appropriate training was undertaken and cases were performed as dual consultant procedures with intraoperative radiography or robotic assistance.

Outcomes were collated prospectively. These included basic demographics, intraoperative details, complication rates and Oxford Hip Scores.

A total of 48 patients underwent DAA THR over 1 year. Mean age was 67 and ASA 2. Over this time period 140 posterior approach and 137 anterolateral approach THR's were performed with available data. Propensity score matching was performed on a 1:1 basis using BMI, Age, Sex and ASA as covariates to generate a matched cohort group of conventional approach THR (n=37)

Length of stay was significantly reduced at 1.95 days (p<0.001) with DAA compared to Anterolateral and Posterior approach. There was no significant difference with length of surgery, blood loss, Infection, dislocation and periprosthetic fracture rate. There was no significant difference in Oxford Hip Score between any approach at 3 months or 1 year.

The transition to this approach has not made a negative impact despite its associated steep learning curve, and has improved efficiency in elective surgery. From our experience we would suggest those changing to this approach receive appropriate training in a high-volume centre, and perform cases as dual consultant procedures.

Introduction

While clinically successful for decades, CR TKA is persistently compromised by inconsistent PCL function. Problems of mid-flexion instability, incomplete knee flexion, erratic kinematic behavior and posterior instability, not seen with PS devices, raise concerns about the consistency of the technique, and the devices used. Most TKA systems offer at least 2 different geometries of tibial inserts to address this clinical problem.

We hypothesize these problems are a result of compromise of PCL anatomy. To avoid compromise to the PCL 3 steps are required: 1) The slope of tibial resection must be less than 5°; 2) the depth of tibial resection must be based off the insertion footprint of the PCL, not the deficiencies of the tibial articular surface; and 3) the tibial insert must be modified to allow intraoperative balancing of the PCL.