Efficacy and safety of regional analgesic techniques on early postoperative knee rehabilitation after total replacement

Abstract EN

Objective : because the choice of the analgesic technique should be based on a careful evaluation of the benefits and risks, so this work aimed to evaluate the efficacy and safety of different analgesic techniques on early postoperative knee rehabilitation after total knee arthroplasty (TKR).

Methodology : Thirty two patients (13 males, 19 females) undergoing unilateral TKR under general anesthesia (GA) were included in this study.

They were randomly divided into 4 groups; each group included 8 patients.

Group A : Postoperative analgesia was administered with continuous epidural infusion technique.

Group B: Postoperative analgesia was administered by continuous epidural infusion technique together with high frequency low intensity transcutaneous electrical nerve stimulation (TENS).

Group C : Postoperative analgesia was administered with continuous femoral 3-in-1 block.

Group D: postoperative analgesia was administered with continuous femoral 3-in-1 block together with high frequency low intensity transcutaneous electrical nerve stimulation.

Postoperative pain was assessed in all groups at rest and during continuous passive motion (CPM) ; using a visual analogue scale (0 : no pain, 100 severe pain) at 24 and 48 h.

Postoperative maximal amplitude of knee flexion was measured at 24 h, 48 h, 7th day, 14th day and at one month with a plastic goniometer.

Supplemental postoperative analgesia was standardized in the 4 groups.

All supplementary subcutaneous injections of morphine administered were recorded.

Side effects arising from analgesic techniques application of the 4 groups were recorded at 24 and 48 hours.

Results : the efficacy in controlling pain and improvement of knee flexion after knee surgery (TKR) was evident in our results in all 4 groups; with a marked improvement in group B and group D (B Vs A ; p < 0.001 and D Vs C ; p < 0.001) ; who had been administered TENS therapy as an adjuvant analgesia.

Also our results demonstrated that the analgesic effect induced by continuous epidural infusion (group A, B) was more greater than achieved by application of continuous 3-in-1 block “group C, D” (where group A Vs C ; p < 0.001 and group B Vs D ; p < 0.01).

Also our results demonstrated that continuous 3-in-1 block technique was safer than continuous epidural infusion technique to provide postoperative analgesia after TKR.

Conclusions : the efficacy of the tested analgesic techniques in all groups in controlling pain after knee surgery (TKR) was evident in our results.

TENS adjuvant therapy groups (B, D) had been shown to have a more significant effect on postoperative pain and early knee mobilization than the non-adjuvant TENS therapy groups (A, C) ; and this reflect the significant effect of TENS in relieving of postoperative pain and increasing the range of motion leading to early restoration of active muscle movement.

The efficacy of continuous 3-in–1 block appeared less than continuous epidural infusion analgesia.

The more safe analgesic technique was found in our study is continuous 3-in-1 block.

Recommendations : because TENS (which is very safe analgesic tool) was found to have a valuable effect in controlling postoperative pain.

So to obtain satisfied quality regarding the efficacy and safety ; we recommend to use two techniques together to provide analgesia after TKR i.e.

Continuous 3-in-1 block together with transcutaneous electrical nerve stimulation.