Lateral unicondylar knee arthroplasty (UKA): Contemporary indications, surgical technique, and results

Abstract

Unicompartmental femoro-tibial osteoarthritis usually affects the medial compartment of the knee, but in 10%, the lateral compartment is primarily involved. Femoral osteotomy is attractive to avoid TKA in younger patients with low-grade unicompartmental osteoarthritis and a valgus deformity. However, only limited functional results can be expected for patients with Ahlback grade 2 or greater osteoarthritis. Moreover, because of previous skin incisions and hardware removal, TKA after femoral osteotomy remains a complex procedure with poor functional results. Unicompartmental knee arthroplasty for both the medial and the lateral compartments has been performed since the 1970s. In a patient with involvement of only one compartment, a medial or a lateral UKA can provide a quicker recovery and enhanced function when compared to TKA. In addition, it preserves bone stock and can be "easily" revised by a TKA. Technical improvements, combined with strict patient selection, have resulted in ten year survivorships greater than 90%. However, lateral UKA is technically more challenging than medial UKA due to the lower number of indications, as well as the functional anatomy of the lateral compartment. The goals of this article are to present up-to-date information concerning indications, patients' selection, surgical technique and results of lateral compartment UKA.

Survivorship and clinical outcome of the minimally invasive Uniglide medial fixed bearing, all-polyethylene tibia, unicompartmental knee arthroplasty at a mean follow-up of 7.3years

“…10-year cumulative revision rates of approximately 12-13.5 % and 11.78 % (CI 95% 11.80-13.34) were reported for fixed bearing UKR in the 2014 Swedish Knee Arthroplasty Register (SKAR) and the 11 th annual report of the National Joint Registry England and Wales (NJR) respectively. Medial and lateral UKAs show similar survival rates based on recent studies [26,33,34].…”

Moderne unikondyläre Kniearthroplastik

“…Gleichzeitig ist jedoch der Screw-home-Mechanismus mit Außen-rotation der Tibia in voller Streckung zu beachten. Wichtig ist daher eine ausreichende Innenrotation der Tibiakomponente, um ein strecknahes Impingement zwischen Femurkomponente und Tuberculum laterale zu verhindern [29]. Bei medialer und lateraler UKA sollte der sagittale Tibiaschnitt den horizontalen nicht unterschneiden, da ansonsten eine erhöh-te Frakturgefahr besteht [32].…”

“…Der "precut" führt jedoch zu einem Verschieben der Femurkomponente nach anterior und einem "downsizing" der Femurkomponente. Wenn der Flexionsspalt zu weit ist, [29].…”

Patient-specific instrumentation improves alignment of lateral unicompartmental knee replacements by novice surgeons

“…LUKR is a smaller, safer, cheaper and more effective operation than TKR for the treatment of lateral compartment arthrosis [5,13]. On this basis LUKR should be a popular procedure.…”