Correlation of intraoperative anthropometric measurement of resected Thai distal femurs between unisex and gender-specific implants.

OBJECTIVE

To measure the intraoperative anthropometric dimensions of Thai distal femurs in order to correlate that data with unisex and gender-specific TKR implants, and to analyze the suitability of gender-specific prostheses for Thai female knees.

MATERIAL AND METHOD

Two hundred Thai patients (170 females and 30 males) who underwent unilateral TKR were recruited. Three parameters of resected distal femurs were measured intraoperatively including anteroposterior dimensions of medial (APM) and lateral (APL) condyles, and mediolateral (ML) width of total condyles which were compared with the dimensional data of two femoral implant components, Nexgen LPS-Flex and Gender Solution Nexgen LPS-Flex. Scatter diagrams were used to assess compatibility; the final type and size of implanted prostheses were recorded.

RESULTS

Thai females had significantly smaller knees than Thai males. The femoral components of both types of prostheses were found to have a tendency toward ML under-coverage in both female and male femurs. These mismatches were more noticeable when small-sized, gender-specific prostheses were used. The overall rate of use of gender-specific components in this study was 15%.

CONCLUSION

The unisex and gender-specific prostheses evaluated in this study do not appear suitable for Thai knees. Particular modifications of implants are required for Thai knees.