Summary

Lateral UKA, done by robotic arm-assistance is precise and well executed with promising early follow-up in Indian patients.

Abstract

Lateral compartment osteoarthritis is seen in only 10% of unicompartmental knee arthritis which is well tolerated for a longer period of time than medial compartment osteoarthritis. The lateral unicompartmental knee arthroplasty (UKA) is a more technically challenging operation, where component placement is very critical to long-term success.

Methods

Our study involved 6 patients who underwent Robotic-arm assisted Lateral UKA over a 2-year period between May 2018 and January 2020 at a single centre. None of the patients were lost to follow-up. 5 female & 1 male patients, age range: 45-72.Overall satisfaction on a five-level Likert scale, clinical outcome based on the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Modified Forgotten Joint Score (MFJS) and radiological outcomes based on the Hip-Knee-Ankle (HKA) axis, femorotibial angle (FTA), tibial posterior slope (PS) obtained were compared preoperatively and postoperatively.

Results

At a mean follow-up period of 23.84 months, among 6 patients 33.3% were very satisfied, 50% were satisfied and 16.7% felt neutral. The mean KOOS changed from 63.03 ± 3.52 to 93.95 ± 3.25 and the mean MFJS was 75.41 ± 10.29 postoperatively. The mean HKA axis changed from 175.92° ± 2.93 valgus to 180.12° ± 2.46 neutral alignment, The mean correction attained was from 4.08° ± 2.93 valgus deformity to 0.12° ± 2. The mean FTA and the mean PS changed from 7.24° ± 4.19 of valgus to 1.92° ± 1.82 of valgus and 83.6° ± 1.96 to 85.6° ± 1.96 respectively

Conclusion

The mean preoperative and postoperative KOOS showed a statistical significance with a p-value of 0.028 (<0.05), showing significant improvement with Robotic-arm assisted lateral UKA which is a well planned & precisely executed with a high success rate in the early follow-up.