Medial unicondylar knee arthroplasty combined to anterior cruciate ligament reconstruction.

Purpose: The purpose of the present study was to retrospectively evaluate the outcomes of patients who underwent combined medial unicompartmental knee arthroplasty (UKA) and anterior cruciate ligament (ACL) reconstruction. The hypothesis was that this procedure would lead to a high success rate in patients affected by isolated medial unicompartmental osteoarthritis and concomitant ACL deficiency.
Methods: Fourteen patients with primary ACL lesion and concomitant medial compartment symptomatic osteoarthritis treated from 2006 to 2010 were followed up for an average time of 26.7 months (SD 4.2). Assessment included KOOS score, Oxford Knee score, American Knee Society scores, WOMAC index of osteoarthritis, Tegner activity level and objective examination including instrumented laxity test with KT-1000 arthrometer. Radiological assessment was done with standard simple radiographs in order to get information about any presence of loosening of the components.
Results: KOOS score, OKS, WOMAC index and the AKSS improved significantly after surgery (p < 0.001). Regarding AKSS, improvement was noted both in the objective score and in the functional one (p < 0.001). There was no clinical evidence of instability in any of the knees as evaluated with clinical laxity testing. No pathologic radiolucent lines were observed around the components. In one patient signs of osteoarthritis in the lateral compartment were observed 28 months after surgery.
Conclusions: UKA combined with ACL reconstruction is a valid therapeutic option for the treatment of combined medial unicompartmental knee osteoarthritis and ACL deficiency in young and active patients and confirms subjective and objective clinical improvement 2 years after surgery. The use of a fixed-bearing prosthesis represents a reliable feature as it allows to overcome problems of improper ligament tensioning during the implantation of the components.
Level of Evidence: IV.