Summary

These findings emphasize the importance of knee extensor muscle strength in preoperative preparation for TKA.

Abstract

Background

To investigate the effect of preoperative knee isokinetic muscle strength (IMS) and presence of sarcopenia on total blood loss (TBL), postoperative day 7 (POD7) pain, range of motion (ROM), and physical performance test in total knee arthroplasty (TKA).

Method

This retrospective study involved 115 patients scheduled for TKA from August 2021 to March 2023. Based on the presence of sarcopenia, all patients were divided into normal and sarcopenia groups. Preoperative IMS by biodex, TBL, POD7 ROM, pain, and physical performance test were measured.

Results

28 patients were categorized as sarcopenia group. Patients’ extensor strength was found significantly lower in sarcopenia group. Compared to normal group, the sarcopenia group had lower TBL (P < 0.001), greater postoperative ROM (P < 0.001), less postoperative pain (P < 0.001), better physical performance results (P < 0.001) at POD 7. The higher IMS was also correlated with lower TBL and higher ROM and physical performance results.

Conclusion

Patients with sarcopenia were found higher total blood loss and lower functional outcomes in early period after TKA. Furthermore, the higher knee IMS was also correlated with lower TBL and better functional outcomes. These findings emphasize the importance of knee extensor muscle strength in preoperative preparation for TKA.