The options for treatment of the young active patient with isolated symptomatic osteoarthritis of the medial compartment and pre-existing deficiency of the anterior cruciate ligament are limited. The indications for the unicompartimental knee prosthesis are selective. Misalignment femoral-tibia, varo-valgus angle more than 7°, over-weight, and knee instability were considered to be a contraindication. The potential longevity of the implant and levels of activity of the patient may preclude total knee replacement, and tibial osteotomy and unicompartmental knee arthroplasty are unreliable because of the ligamentous instability. Therefore, we combined reconstruction of the anterior cruciate ligament first and unicompartmental arthroplasty of the knee. We included in this study six patients, three males and three female, mean age 53.6 years, that presented only osteoarthritis of medial femoral condyle and ACL deficiency. In the first group included 2 patients, we performed arthroscopy ACL reconstruction with hamstring and unicompartimental knee prosthesis one-step, and in the second group included 4 patients, we performed the same surgical procedure in two-step. The clinical and radiological data at a minimum of 1.5 years at follow-up. We evaluated all patients with KOOS score, and IKDC score. At the last follow-up, no patient had radiological evidence of component loosening, no infection, no knee remainder instability. The subjective and objective outcome assessed with the scale documented satisfactory average results, both in patients of first group and in those of second group. ACL deficiency induced knee osteoarthritis for incorrect knee biomechanics, and all patients could be submit a total knee replacement. What method for preventing it? This combined surgical treatment seems to be a viable treatment option for young active patients with symptomatic arthritis of the medial compartment, in whom the anterior cruciate ligament has been ruptured. Future developments and more data are necessary for standardised surgical approach.
