Assessing Functional Outcomes and Pain Intensity Variations After Total Knee Arthroplasty: A Comparative Analysis of Pain Block Techniques

OBJECTIVE: This study aimed to compare post-total knee arthroplasty (TKA) outcomes (function, pain, and quadriceps strength) between femoral nerve block (FNB), intra-articular block, and a control group. In addition, it sought to identify predictors of postoperative functional capacity. METHODS: Fifty-four TKA patients were evaluated. Preoperative assessments included quadriceps strength and the Oxford knee score. Postoperative assessments on days 1 and 3/4 included the timed up and go (TUG), Elderly Mobility Scale, and Five Times Sit-to-Stand tests. Pain levels, hospitalization duration, surgical time, complications, and falls were also recorded. RESULTS: No significant differences in functional outcomes, pain levels, or quadriceps strength were found between the FNB, intra-articular block, and control groups, except for the TUG test on day 3/4, which favored FNB (P < 0.01). Preoperative quadriceps strength was a valuable predictor of early functional outcomes, with FNB improving TUG scores on day 3/4. DISCUSSION: The choice of pain block technique had limited effect on short-term functional outcomes post-TKA, except for early mobility as measured by the TUG test on day 3/4. Preoperative quadriceps strength markedly predicted initial functional performance. Additional research is needed to enhance postoperative pain management and early rehabilitation strategies. CLINICAL TRIAL REGISTRATION NUMBER: NCT05478005.