Minimally invasive Oxford medial unicompartmental knee replacement in patients 50 years of age or younger

Tilman Walker; Julius Stupp; Tobias Reiner; Benjamin Panzram; Timo A Nees; Moritz M Innmann; Tobias Gotterbarm; Christian Merle

doi:10.1007/s00402-022-04539-6

Minimally invasive Oxford medial unicompartmental knee replacement in patients 50 years of age or younger

Arch Orthop Trauma Surg. 2023 Jun;143(6):3077-3084. doi: 10.1007/s00402-022-04539-6. Epub 2022 Jul 18.

Authors

Tilman Walker¹, Julius Stupp¹, Tobias Reiner¹, Benjamin Panzram¹, Timo A Nees¹, Moritz M Innmann¹, Tobias Gotterbarm², Christian Merle³

Affiliations

¹ Department of Orthopaedic Surgery, University of Heidelberg, Schlierbacher Landstrasse 200a, 69118, Heidelberg, Germany.
² Center for Orthopaedics and Trauma Surgery, University of Linz, Krankenhausstr. 7a, 4020, Linz, Austria.
³ Department of Orthopaedic Surgery, University of Heidelberg, Schlierbacher Landstrasse 200a, 69118, Heidelberg, Germany. christian.merle@med.uni-heidelberg.de.

Abstract

Introduction: The aim of the present study was to assess clinical outcome and mid-term survivorship of mobile-bearing unicompartmental knee arthroplasty in patients 50 years of age or younger.

Methods: This study reports the results of 119 patients (130 knees) following mobile-bearing medial UKA. Primary indication was advanced osteoarthritis or avascular necrosis of the femoral condyle. The anterior cruciate ligament (ACL) as well as the collateral ligaments were functionally intact, the varus deformity was manually correctable and there was no evidence of osteoarthritis in the lateral compartment. Survivorship analysis was performed with different endpoints and clinical outcome was measured using the Oxford Knee Score (OKS), American Knee Society Score and Functional Score (AKSS-O, AKSS-F), range of motion (ROM), Tegner activity score, University of California Los Angeles score (UCLA) and visual analogue scale for pain (VAS).

Results: The survival rate was 96.6% at 6.5 years (95% CI 98.7-91.3%; number at risk: 56) and 91.7% (95% CI 96.7-80%; number at risk: 22) at 10 years for the endpoint device related revisions and 91.5% at 6.5 years (95% CI 95.4-84.5%; number at risk: 56) and 86.8% (95% CI 93-76.2%; number at risk: 22) at 10 years for the endpoint revision for any reason. Outcome scores, VAS and ROM showed significant improvements (p < 0.001). The mean OKS increased from 26.7 (standard deviation (sd): 7.2) preoperatively to 40.9 (sd: 7.6) at final follow-up, the mean AKSS-O from 48.3 (sd: 13.3) to 87.8 (sd: 14.4) and the mean ROM from 118° (sd: 16.7) to 125° (sd: 11.4). The radiological analysis revealed progression of degenerative changes in the lateral compartment in 39.6% of patients without affecting the functional outcome.

Conclusions: Medial mobile-bearing UKA is a viable surgical treatment option in young patients with significant improvements in knee function and pain. Further follow-up is necessary to evaluate the long-term efficacy.

Level of evidence: Retrospective cohort study, Level III.

Keywords: Knee osteoarthritis; Medial unicompartmental knee arthroplasty; Mobile bearing; Oxford prosthesis; Partial knee replacement; UKA; UKR; Young patients.

MeSH terms

Arthroplasty, Replacement, Knee* / adverse effects
Follow-Up Studies
Humans
Knee Joint / surgery
Knee Prosthesis* / adverse effects
Osteoarthritis, Knee*
Pain / etiology
Retrospective Studies
Treatment Outcome