Does Preemptive Femoral Nerve Block Provide Additional Pain Relief for Periarticular Injection in Total Knee Arthroplasty?
Inthiporn Kositanurit MD1, Siriluk Toolyodpun MD1, Surachart Podjanasupawun MD1, Supachok Rasamimongkol MD2, Santi Weerakul MD2, Artit Laoruengthana MD2
Affiliation : 1 Department of Anesthesiology, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand 2 Department of Orthopaedics, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand
Background : Severe postoperative pain following total knee arthroplasty [TKA] may cause patients agony and persistent
postsurgical pain [PPSP]. Periarticular injection [PAI] and femoral nerve block [FNB] are widely accepted as effective
options for reducing postoperative pain and morphine consumption. Preemptive analgesia theoretically can has the ability
to prevent sensitization of the nervous system and consequent amplification of postoperative pain.
Objective : To explore whether the preemptive femoral nerve block [FNB] can provide additional pain relief for periarticular
injection [PAI] after primary TKA.
Materials and Methods : The records of 112 patients, 53 who had received spinal anesthesia with periarticular injection (PAI
group) and 59 who had received spinal anesthesia combined with preemptive femoral nerve block [FNB] and PAI (FNB +
PAI group) were retrospective analyzed. All the data had been routinely recorded in a sequential fashion at our institution.
Results : Morphine consumption by the FNB + PAI group during the first 24 and 48 hours post operation were 7.13 and
11.61 mg, respectively, significantly lower than the 14.11 and 20.43 mg consumed by the PAI group (p = 0.001, and p = 0.01,
respectively). The FNB + PAI group had lower pain scores in the first 24 hours, although that difference was not statistically
significant. In terms of knee rehabilitation, the degrees of straight leg raise [SLR] in the FNB + PAI group was significantly
higher in the first 24 hours, while, the degrees of knee flexion and extension lag [EL] were comparable between the two
groups.
Conclusion : Preemptive femoral nerve block [FNB] can reduce morphine consumption in the first 48 hours after total knee
arthroplasty. In addition, the FNB tends to reduce the pain score and to facilitate knee rehabilitation on the first day after the
index surgery.
Keywords : Total knee arthroplasty, Femoral nerve block, Periarticular injection, Preemptive analgesia
