No clinical superiority of bi-cruciate retaining versus posterior stabilized total knee arthroplasty at two years follow-up.

The purpose of the present study was to evaluate and compare the clinical outcomes of two groups of patients subject to bi-cruciate retaining (BCR) or posterior-stabilized (PS) implants. It was hypothesized that patients treated with BCR prostheses would present higher flexion and better clinical and functional results than those treated with PS implants. This prospective study included thirty-two patients treated for primary knee osteoarthritis and assigned to two matched groups for their demographic characteristics and comorbidities. Those with functioning cruciate ligaments received bi- cruciate retaining prostheses. In the case of ligaments' insufficiency, the posterior-stabilised design was selected. The primary outcome was knee flexion, and secondary outcomes included the patient's reported outcomes as recorded by the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, visual analogue scale (VAS) for pain, treatment- related complications, and surgical time. Complete data were recorded for all patients with a minimum of 2 years of follow-up. This study found a statistically significant improvement in all the analysed clinical and functional assessment tools from baseline to the latest follow-up (p<0.05) for both groups. However, no statistically significant difference was found between the two groups. Furthermore, bi-cruciate retaining design is surgical time. There was no evidence of clinical superiority of bi-cruciate retaining compared to posterior stabilized knee implants. Therefore, further randomized studies with more participants and a longer follow-up on comparing bi-cruciate retaining and posterior stabilized implants in primary knee osteoarthritis could be rewarding.