To investigate the outcome and prognosis after unicondylar knee replacement in patients with medial interphalangeal arthritis of the knee combined with anterior cruciate ligament dysfunction.

Eighty-seven patients diagnosed with medial interphalangeal arthritis of the knee combined with anterior cruciate ligament dysfunction and treated with medial mobility platform unicondylar replacement at the Department of Orthopaedics, the First Hospital of Hebei Medical University were retrospectively analyzed from January 2019 to January 2021, and the surgical results and prognosis of the patients were assessed by measuring and analyzing the posterior tilt angle of the tibia, the range of knee extensor/flexor motion, the scores of knee injuries and osteoarthritis, and the occurrence of complications.

In the 87 patients included in this study, tibial lordosis was significantly reduced (P<0.05) and knee mobility was significantly improved (P<0.05) compared with those before operation. The scores of pain, symptom, activities of daily living, sport, and KOOS quality of life dimensions of the knee injury and osteoarthritis outcome score (KOOS) were all increased compared with the scores before operation; all these scores, except KOOS symptom score, were significantly higher during the follow-up period compared to those in the preoperative period (P<0.05). During the two-year follow-up, none of the cases required revision, and no loosening, malpositioning, or dislocation of the prosthesis were reported, nor were the complications such as infection, fat embolism, or deep vein thrombosis. All patients had good postoperative knee function and improved quality of life as well as mental status.

Unicondylar knee arthroplasty is feasible to reduce pain, improve quality of life, and achieve a good prognosis for patients with anterior cruciate ligament dysfunction after strict control of indications and detailed evaluation.