Comparison Of The Effect Of Continuous Femoral Nerve Block(CFNB) With And Without Periarticular Injection On Postoperative Analgesia And Knee Rehabilitation After Total Knee Arthroplasty(TKA)

BACKGROUND: With the progress of science and technology and the improvementof people’s living standard, ageing populations gradually increase, osteoarthritispatients due to various reasons are also growing. With the development of medicalscience and technology and the emergence of new technology, total knee arthroplastyhas gradually become a clinical treatment of knee osteoarthritis and the importantmethod of reconstruction of knee joint function. Over600,000total knee arthroplasties(TKAs) are performed annually in the US, yet postoperative pain after total knee arthroplasty remains one of the most important challenges facing patients and surgeonsundergoing this surgery. It is severe in60%of patients and moderate in30%. TheAmerican Pain Society has termed pain as the “fifth vital sign”. Providing a balance ofadequate analgesia while limiting the functional impact of regional anesthesia andminimizing opioid side effects is critical to minimize adverse events and improvepatient satisfaction. Pain control after total knee arthroplasty is integral in theimmediate postoperative period for early rehabilitation. An ideal analgesic modalityfor post-TKA rehabilitation should permit adequate knee flexion with minimal painand without motor impairment, resulting in successful mobilization. Effective painmanagement following total knee arthroplasty is fundamental in achieving positiverehabilitation outcomes. Poor control of postoperative pain after TKA may cause aseries of adverse events that could negatively influence functional recovery and thefinal results. Numerous different methods of postoperative analgesia are available, buteach has its own risk of adverse side effects.Although the analgesic effects of periarticular multimodal drug injection (PMDI)after TKA have been well documented, there is little information about additional painrelieving effects of PMDI incorporated to contemporary multimodal pain controlprotocols which have been proved to provide excellent analgesia.Comparison of the effect of Continuous Femoral Nerve Block(CFNB) withand without Periarticular Injection on Postoperative Analgesia and KneeRehabilitation after Total Knee Arthroplasty(TKA)Objective：To compare the effect of a continuous femoral nerve block with an additionalperiarticular injection on postoperative analgesia and knee rehabilitation after totalknee arthroplasty(TKA). Methods:In this prospective, randomized controlled study,40ASA physicalstatusⅠ-Ⅱpatients scheduled for selective primary unilateral total knee arthroplastyunder spinal anesthesia(SA) were selected. All patients received a standard continuousfemoral nerve block(0.2%ropivacaine,6ml/h) and the stimulating catheters remainedindwelling for72hours after operation. The patients were allocated into two groups. Inthe wards, patiens in GroupⅠwere maintained by periarticular injection of0.25%ropivacaine and5mg dexamethasone injection(20ml in total). GroupⅡweremaintained by20ml normal saline.Results:The2treatment groups had similar WOMAC and HSS scores for the mean area.Mean maximal VAS scores during physical therapy were significantly lower amongpatients who received periarticular injection versus placebo(VAS:PO8hr，12hrp-value<0.01,POD1p-value<0.05).The maximal continuous passive motion amplitudeof periarticular injection were significantly larger than that of placebo group(CPMamplitude: POD2,p-value<0.01,POD3p-value<0.05).There were no complicationsresulting from the technique and the level of patient satisfication was high.Conclusions：A femoral nerve block combined with periarticular injection attenuates pain moreeffectively and is associated with better knee rehabilitation.