According to French expert recommendations (Fuzier et al. 2007), it is recommended to use peripheral blocks for postoperative analgesia of arthroplasty surgery compared with epidural analgesia. The benefit of analgesia with peripheral blocks is also true with intravenous patient-controlled analgesia with morphine pump. Indeed perineural blocks minimize the sympathetic response to surgery, reduced postoperative pain especially during mobilization, improve analgesia during the postoperative period and increase patient’s satisfaction.

The cost of a single ultrasound-guided peripheral nerve block injection is estimated at $20.85 including the needle, aseptic equipment, injection equipment, local anaesthetic and a set of protection of the ultrasound probe. The cost of this technique of analgesia with continuous injection of ropivacaine for 72 h is estimated at $77 (Table 12.2).

Today, it’s not mandatory to use ultrasound for a peripheral nerve block (single injection or catheterization). Indeed, the evaluation of the cost-effectiveness of locoregional analgesia ultrasound guided versus neurostimulation has not yet been evaluated. The cost of an ultrasound is around $54 630 plus the prices of disposables (ultrasound gel, sterile protection of ultrasound probes, plus the cost of maintenance), while a neurostimulator costs about $1,161. Up to now, the superiority of ultrasound compared with neurostimulation on the success of locoregional anaesthesia has not been demonstrated. There is however several advantages for ultrasound: a direct visualization of the needle and of the surrounding tissue and the dissemination of local anaesthetic. Ultrasound helps to decrease time required to perform the nerve blocks, the number of needle’s redirection and the number of vascular punctures and decrease the setting time of nerve blocks (Casati et al. 2007; Domingo-Triadó et al. 2007; Marhofer et al. 1998; Soeding et al. 2005). Ultrasound also allows a better understanding of the anatomical variations. There is also a decrease of complications due to systemic toxicity of local anaesthetic (Barrington and Kluger 2013). It also improves patient’s satisfaction by reducing the discomfort of the nerve research by neurostimulation (Koscielniak-Nielsen et al. 2002) and by decreasing pain in trauma patient (Casati et al. 2007; Soeding et al. 2005). The impact on the risk of postoperative neuropathy is less clear, but a trend in favour of ultrasonographic techniques has been outlined (Orebaugh et al. 2012). Thus, the cost of an ultrasound remains the main limitation compared to standard neurostimulation techniques. However, a study published in 2004 reported the same cost for an infraclavicular block under ultrasound and neurostimulation (the introduction of a catheter costs only 13.90 dollars more with ultrasound) (Sandhu et al. 2004). Another study published in 2012 compared the cost- effectiveness of the analgesia produced by an ultrasound-guided popliteal sciatic catheter inserted with the same block by neurostimulation approach. The use of ultrasound is associated with a higher probability of success and reduced the costs about 84.7 % (Ehlers et al. 2012).

For postoperative analgesia, a femoral nerve block with a single injection is recommended (Comité douleur-anesthésie locorégionale et le comité des référentiels de la Sfar 2008b).

The debate is over: the French guidelines recommend the use of a femoral perineural catheter, probably associated with a single-injection sciatic nerve block (Comité douleur-anesthésie locorégionale et le comité des référentiels de la Sfar 2008b; Eledjam and viel 2013), while an European working group (PROSPECT Group) recommend neither a single injection nor a continuous infusion femoral nerve block because of too much heterogeneity among studies (Fischer et al. 2008).

If the implementation of a femoral nerve block, at least as a single injection, seems obvious to improve the management of acute and chronic pain after TKA, the effect of a sciatic block has to be demonstrated. Indeed, Wegener et al. (2013) did not find any significant difference in terms of functional recovery, and acute and chronic pain in patients who underwent TKA with a continuous femoral block alone or combined with a single or continuous injection sciatic nerve block. Sinha et al. (2012) found an improvement of postoperative acute pain in patients with a femoral catheter associated with a sciatic block or elective tibial block.

Thus, peripheral nerve blocks after arthroplasty surgery improve management of acute and chronic pain (Liu et al. 2012), reduce postoperative morphine consumption and improve patient’s satisfaction (Fischer et al. 2008). However, the locoregional anaesthesia leads to postoperative quadriceps paresis whatever the concentration and volume of the local anaesthetic (Bauer et al. 2012). It may alter the initial functional recovery and increase the number of falls (Johnson et al. 2013).