After ACL reconstruction, patients who received a femoral nerve block for pain control had a 13% motor/sensory complication rate, according to a study published in Arthroscopy. However, strength and functional deficits were not permanent and were not different vs. controls at 9-month follow-up.
“[Although] reports have previously noted strength deficits in the immediate postoperative period following femoral nerve blocks, these deficits are not permanent and do resolve at long-term follow-up,” Kelechi R. Okoroha, MD, told Healio.com/Orthopedics. “Our study found that at 9 months postoperatively, there was no difference in isokinetic flexion strength, extension strength or functional test between patients receiving a femoral nerve block and local infiltration when undergoing an ACL reconstruction. However, only 40% of patients reached maximal strength and 63% of patients reached maximal function.”
Kelechi R. Okoroha
He added, “These results suggest that at normal return-to-play time, a significant portion of athletes have not regained full strength and function and could benefit from additional rehab. Future studies should identify these patients for continued rehabilitation and objective testing before return, as they may be at risk for re-injury.”
Okoroha and colleagues randomized 43 patients who underwent ACL reconstruction to receive either a preoperative single-shot femoral nerve block or local infiltration anesthesia. After surgery, all patients underwent a standardized rehabilitation program. At 9 months postoperatively, investigators used a Biodex machine to test isokinetic strength and function and compared results between the operative and nonoperative extremity.
Results showed that at an average of 10.6 months postoperatively, there was no difference in strength seen between the femoral nerve block and the control groups. Investigators noted there was no difference seen between the femoral nerve block and control groups with regard to the slow isokinetic extension strength, fast isokinetic extension strength, slow isokinetic flexion strength and fast isokinetic flexion strength. No difference was also seen in deficits for the single-leg hop distance, timed single-leg hop and single-leg triple hop distance.
According to researchers, 40% of patients achieved maximal strength within 15% of the contralateral limb. At an average of 10.6 months postoperatively, 63% of patients achieved maximal function. – by Monica Jaramillo
: The researchers report no relevant financial disclosures.