Knee arthroplasty with a medial rotating total knee replacement. Midterm clinical findings: A district general experience of 38 cases

•Here we review the clinical and radiological outcomes of the medial rotation knee at mid-term follow up (4 years).•38 prostheses were evaluated in a single surgeon series.•Learning curve has been assessed.•Results are comparable to standard TKR.•Further work is needed to assess high-end function.

BackgroundThe Medial Rotating Knee replacement (MRK) was first used in 1994, reporting high rates of satisfaction. It is designed to replicate natural knee kinematics and improve stability and function. There are limited studies on the mid-term clinical outcomes, in particular in a district general hospital (DGH) environment. This is the first study that we are aware of that evaluates the learning curve of the implementation of this knee system in this environment.Patients/methodBetween 2007 and 2009 we performed 38 consecutive MRK replacements (MAT ORTHO, UK) in 36 patients. The mean follow-up was four years. Patients were evaluated clinically, using OKS and patient questionnaire and radiographically (good/acceptable/poor) to assess outcome.ResultsMean age was 73.0 years. Mean pre-operative OKS was 17.7 (range 8–29), which rose to 38.1 (range 23–48) at latest follow up (p < 0.005). Overall 71% of the patients were either satisfied (29%) or very satisfied (42%). 81% felt an improvement of the ability to go up or down stairs and 92% felt stable.All poor radiographic and the majority of acceptable outcomes were experienced in the first 50% of cases.ConclusionThe MRK can be successfully implanted in a DGH environment. It improves pain and function comparably to standard TKRs, however, subjective improvement may be higher. Radiographic evaluation shows an acceptable learning curve.Level of evidenceLevel IV case series.