Comparison of the Therapeutic Effect Between the Simultaneous and Staged Unicompartmental Knee Arthroplasty (UKA) for Bilateral Knee Medial Compartment Arthritis

Background: To compare the efficacy and safety of simultaneous vs staged unicompartmental knee arthroplasty (UKA) for bilateral unicompartmental osteoarthritis of the knee.

Methods: We performed a retrospective analysis of prospectively collected data on 93 patients with bilateral knee medial compartment arthritis underwent simultaneous UKA (Group A, 39) or staged UKA (Group B, 54 cases) from January 2008 to December 2015. Group A: 6 males and 33 females aged 64.9 ± 7.7 years; Group B: 5 males and 49 females aged 64.2 ± 6.4 years. There were no statistically significant differences in pre-operative age, sex ratio, or body weight index between the groups (P > 0.05). Groups were compared in terms of total anesthesia time, volume of drainage, blood transfusion rate, hemoglobin level on post-operative day 3, total post-operative inpatient days, treatment expenses, post-operative therapeutic effect (KSS scores), and complications.

Results: All patients had follow-up visits post-operatively. The follow-up visit interval was 32-133 months and 41.9 months on average. Total anesthesia time, postoperative length of hospital stay, and hospitalization expenses in Group A were significantly less than those of Group B (P < 0.05). Hemoglobin levels in Group A were significantly lower than those of Group B at post-op day 3 (P < 0.05). However, no significant differences in volume of drainage, the rate of transfusion, complications, and KSS scores were detected between Groups A and B (P > 0.05).

Conclusions: Both simultaneous and staged UKA achieved the desired therapeutic effect in treatment of bilateral knee medial compartment arthritis. However, simultaneous UKA reduced the cost and the postoperative length of hospital stay without increasing post-operative complications.