Which knee replacement do the patients forget? Unicondylar or total knee arthroplasty.

OBJECTIVE

The aim of this study was to determine which type of knee arthroplasty is easier to forget by comparing levels of joint awareness evaluated with the Forgotten Joint Score (FJS-12) after unicondylar versus total knee arthroplasty.

METHODS

Patients who underwent either unicondylar or total knee arthroplasty due to primary gonarthrosis were retrospectively identified and then divided into 2 groups: the TKA group (218 patients; mean age = 68.93 ± 7.14 years) and the UKA group (131 patients; mean age = 60.39 ± 7.03 years). The status of joint awareness after knee replacement surgery was assessed using the Turkish version of the FJS-12 at the final follow-up by telephone interview. Also, The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and The EuroQol five-dimensional (EQ-5D) scores were obtained to assess the clinical status of the patients.

RESULTS

The mean follow-up was 2.8 years (range = 24-49 months) in the TKA group and 3.2 years (range = 24-50 months) in the UKA group. The FJS-12 was significantly higher in the UKA group (73.60 ± 9.95) than in the TKA group (64.88 ± 9.47) (P = .001). The WOMAC score was significantly better in the UKA group (81.39 ± 9.84) than in the TKA group (74.92 ± 9.99) (P = .001). No significant difference in EQ-5D existed between the groups (0.76 ± 0.14 for the TKA group, 0.79 ± 0.17 for the UKA group; P = .441). In terms of gender, the FJS-12 showed no differences between the groups; however, more favorable scores were recorded in younger patients with UKA.

CONCLUSION

The results of this study have demonstrated that UKA may be better than TKA in terms of the patient perception of pain, stiffness, and physical functioning.

LEVEL OF EVIDENCE: Level IV, Therapeutic Study.