Lateral Cutaneous Nerve Research Articles

The outcome of surgically treated traumatic unstable pelvic fractures by open reduction and internal fixation

:Background:This study was performed to evaluate functional and radiological results of pelvic ring fractures treatment by open reduction and internal fixation. Methods:Thirty eight patients with unstable pelvic fractures, treated from 2002 to 2008 were retrospectively reviewed. The mean patients’ age was 37 years (range 20 to 67). Twenty six patients were men (4patients with type B and 22 patients with type C fracture) and 12 women (7 patients with type B and 5 patients with type C fracture). The commonest cause was a road traffic accident (N=37, about 97%). Internal fixation was done by plaque with ilioinguinal and kocher-langenbeek approaches for anterior, posterior pelvic wall and acetabulum fracture respectively. Quality of reduction was graded according to Majeed score system. Results:There were 11 type-C and 27 type-B pelvic fractures according to Tile’s classification. Thirty six patients sustained additional injuries. The commonest additional injury was lower extremity fracture. The mean follow-up was 45.6 months (range 16 to 84 months).The functional outcome was excellent in 66%, good in 15%, fair in 11% and poor in 7% of the patients with type B pelvic fractures and functional outcome was excellent in 46%, good in 27%, fair in 27% and poor in 0% of the patients with type C pelvic fractures. There were four postoperative infections. No sexual functional problem was reported. Neurologic problem like Lateral cutaneous nerve of thigh injury recovered completely in 2 patients and partially in 2 patients. There was no significant relation between functional outcome and the site of fracture (P greater than 0.005). Conclusions:Unstable pelvic ring fracture injuries should be managed surgically by rigid stabilization. It must be carried out as soon as the general condition of the patient permits, and even up to two weeks.

The significance of tibial and common peroneal nerves in nerve blocks

The aim of this study was to elucidate the anatomical location of tibial nerve (TN) and common peroneal nerve (CPN) in the popliteal crease for specific nerve block. Fifty fresh specimens from 27 adult Korean cadavers (16 males and 11 females, age 35-87years) were investigated. Five of the 27 cadavers were used to determine the depths of nerves in cross-section. Tibial nerve was located 50% from the most lateral point of the popliteal crease and 1.4-cm deep to the surface. In 20% of the 50 specimens, the medial sural cutaneous nerve branched out below or at the popliteal crease, whereas the CPN was located at 26% from the most lateral point of the popliteal crease and 0.7-cm deep from the surface. Furthermore, in 6% of specimens the lateral sural cutaneous nerve branched out below or at the popliteal crease. The results concerning the location of the TN and CPN at the popliteal crease offer a good guide to optimal nerve block.

Meralgia Paresthetica After Bariatric Surgery in Iranian Patients

Meralgia paresthetica (MP) is a benign clinical syndrome of entrapment of the lateral cutaneous nerve in the thigh. Among the complications of bariatric sur-gery, neurologic complications are not uncommon and of these complications, MP is a frequent clinical diagnosis. Thus, knowing the clinical risk factors of MP is of great im-portance as they help with the differential diagnoses of MP from other serious disorders.

Repair of a median nerve transection injury using multiple nerve transfers, with long-term functional recovery

Complete loss of median nerve motor function is a rare but devastating injury. Loss of median motor hand function and upper-extremity pronation can significantly impact a patient's ability to perform many activities of daily living independently. The authors report the long-term follow-up in a case of median nerve motor fiber transection that occurred during an arthroscopic elbow procedure, which was then treated with multiple nerve transfers. Motor reconstruction used the nerves to the supinator and extensor carpi radialis brevis to transfer to the anterior interosseous nerve and pronator. Sensory sensation was restored using the lateral antebrachial cutaneous (LABC) nerve to transfer to a portion of the sensory component of the median nerve, and a second cable of LABC nerve as a direct median nerve sensory graft. The patient ultimately recovered near normal motor function of the median nerve, but had persistent pain symptoms 4 years postinjury.

Surgical Technique: Repair of Forefoot Skin and Soft Tissue Defects Using a Lateral Tarsal Flap With a Reverse Dorsalis Pedis Artery Pedicle: A Retrospective Study of 11 Patients

Various authors have proposed flaps to reconstruct traumatic forefoot skin and soft tissue defects, especially with exposure of tendon and/or bone although which is best for particular circumstances is unclear. The indications for the technique were a forefoot defect area of no more than 8-cm × 8-cm and a well-preserved lateral tarsal (LT) donor site. The injured tendons were repaired using tendon grafts. The free dorsalis pedis flap was outlined by centering it on the cutaneous branch of the LT artery and tailoring it to the size of the wound, allowing 0.5-cm margins in length and width. The flap was rotated around the plantar perforating branch of the dorsalis pedis artery (DPA) to cover the forefoot defect. The lateral dorsalis pedis cutaneous nerve was anastomosed with the recipient plantar nerve stump. The donor site was covered with an inguinal, full-thickness skin graft. Traumatic forefoot skin and soft tissue defects with exposure of the tendon and/or bone involving 11 feet in 11 patients (mean age, 32 years) were covered using a LT flap with a reversed DPA pedicle. Three patients with forefoot defects underwent emergency repair within 8 hours of injury, whereas eight patients required delayed repair. All patients were followed up for at least 6 months (mean, 13 months; range, 6-24 months). All flaps survived uneventfully, except for two that had superficial marginal necrosis or severe venous insufficiency. All skin grafts covering the donor sites survived and all wounds healed. None of the patients had restricted standing or walking at followups. The two-point discrimination was 4 mm to 10 mm at 6 months postoperative. The mean hallux-metatarsophalangeal-interphalangeal scale score was 93 points (range, 87-98 points). Our observations suggest the LT flap with a reversed DPA pedicle is a reasonable option for repair of traumatic forefoot skin and soft tissue defects with exposure of tendon and/or bone but a well-preserved LT donor site and is associated with minimal morbidity.

Complications Following Distal Biceps Repair

Distal biceps rupture is a relatively uncommon injury. Surgical repair is performed in patients who seek increased flexion and supination strength over that which results from nonoperative treatment. The purpose of this study was to evaluate complications associated with surgical repair of the distal biceps tendon in a large series of patients. We retrospectively reviewed 198 consecutive patients with distal biceps ruptures treated with surgical repair, and evaluated time from injury to repair, surgical technique, and complications. A total of 72 patients (36%) developed complications; 6 patients underwent additional surgery. Minor complications included lateral antebrachial cutaneous nerve paresthesia (26%), radial sensory nerve paresthesia (6%), and superficial infection (2%). Major complications included posterior interosseous nerve injury (4%), symptomatic heterotropic ossification (3%), and re-rupture (2%). Minor complications were common after distal biceps tendon repair; however, most were sensory nerve injuries that resolved with time. Major complications were infrequent, and few patients required revision surgery. Complications were more common after distal biceps tendon repair performed more than 28 days after rupture. Therapeutic IV.

Single Versus Double-Incision Technique for the Repair of Acute Distal Biceps Tendon Ruptures

This clinical trial was done to evaluate outcomes of the single and double-incision techniques for acute distal biceps tendon repair. We hypothesized that there would be fewer complications and less short-term pain and disability in the two-incision group, with no measureable differences in outcome at a minimum of one year postoperatively. Patients with an acute distal biceps rupture were randomized to either a single-incision repair with use of two suture anchors (n = 47) or a double-incision repair with use of transosseous drill holes (n = 44). Patients were followed at three, six, twelve, and twenty-four months postoperatively. The primary outcome was the American Shoulder and Elbow Surgeons (ASES) elbow score. Secondary outcomes included muscle strength, complication rates, and Disabilities of the Arm, Shoulder and Hand (DASH) and Patient-Rated Elbow Evaluation (PREE) scores. All patients were male, with no significant differences in the mean age, percentages of dominant hands affected, or Workers' Compensation cases between groups. There were also no differences in the final outcomes (at two years) between the two groups (p = 0.4 for ASES pain score, p = 0.10 for ASES function score, p = 0.3 for DASH score, and p = 0.4 for PREE score). In addition, there were no differences in isometric extension, pronation, or supination strength at more than one year. A 10% advantage in final isometric flexion strength was seen in the patients treated with the double-incision technique (104% versus 94% in the single-incision group; p = 0.01). There were no differences in the rate of strength recovery. The single-incision technique was associated with more early transient neurapraxias of the lateral antebrachial cutaneous nerve (nineteen of forty-seven versus three of forty-three in the double-incision group, p < 0.001). There were four reruptures, all of which were related to patient noncompliance or reinjury during the early postoperative period and appeared to be unrelated to the fixation technique (p = 0.3). There were no significant differences in outcomes between the single and double-incision distal biceps repair techniques other than a 10% advantage in final flexion strength with the latter. Most complications were minor, with a significantly greater prevalence in the single-incision group.

Normal and sonographic anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb.

The ultrasonographic examination is currently increasingly used in imaging peripheral nerves, serving to supplement the physical examination, electromyography and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive and well-tolerated by patients. The typical ultrasonographic picture of peripheral nerves as well as the examination technique have been discussed in part I of this article series, following the example of the median nerve. Part II of the series presented the normal anatomy and the technique for examining the peripheral nerves of the upper limb. This part of the article series focuses on the anatomy and technique for examining twelve normal peripheral nerves of the lower extremity: the iliohypogastric and ilioinguinal nerves, the lateral cutaneous nerve of the thigh, the pudendal, sciatic, tibial, sural, medial plantar, lateral plantar, common peroneal, deep peroneal and superficial peroneal nerves. It includes diagrams showing the proper positioning of the sonographic probe, plus USG images of the successively discussed nerves and their surrounding structures. The ultrasonographic appearance of the peripheral nerves in the lower limb is identical to the nerves in the upper limb. However, when imaging the lower extremity, convex probes are more often utilized, to capture deeply-seated nerves. The examination technique, similarly to that used in visualizing the nerves of upper extremity, consists of locating the nerve at a characteristic anatomic reference point and tracking it using the “elevator technique”. All 3 parts of the article series should serve as an introduction to a discussion of peripheral nerve pathologies, which will be presented in subsequent issues of the “Journal of Ultrasonography”.

The Lateral Dorsal Cutaneous Branch of the Sural Nerve

Background: Fractures of the proximal fifth metatarsal are one of the most common forefoot injuries encountered by orthopaedic surgeons in sports medicine. The percutaneous surgical approach to Jones fracture fixation and corresponding anatomy has received little attention in the literature to date. Purpose: To describe in detail the location of the lateral dorsal cutaneous nerve (LDCN) and its branches relative to the base of the fifth metatarsal and to the standard lateral approach. Study Design: Descriptive laboratory study. Methods: Ten fresh-frozen cadaveric foot specimens were used for this study. Specimens were dissected at the lateral aspect of the foot over the proximal fifth metatarsal, and the LDCN and its branches were identified. The distance of the LDCN to the superior border of the peroneus brevis tendon (PBT) was measured relative to standard reference points in all specimens, and the presence of an anastomotic branch was noted. A set of vertical and horizontal reference lines were also constructed to determine whether the LDCN or its branches would be compromised by a standard lateral approach. Results: The LDCN was superficial (ie, lateral) and inferior to the superior border of the PBT in all specimens and at all reference points. A bifurcation of the LDCN was present in 8 specimens, located an average of 18 mm posterior and 11 mm dorsal to the base of the fifth metatarsal. The dorsolateral branch and dorsomedial branch of the LDCN each intersected with the base of the fifth metatarsal horizontal line and vertical line, respectively, indicating potential compromise of the nerve with a standard lateral surgical approach. Conclusion: The standard lateral approach to the base of the fifth metatarsal carries a higher risk for surgical injury to the LDCN. A “high and inside” approach that remains superior to the superior border of the PBT is anatomically safe and may decrease the chance of intraoperative nerve injury and irritation postoperatively.

Der minimal-invasive anteriore Zugang

The minimally invasive direct anterior approach for total hip arthroplasty (THA) was first published in 1985. Since then the technique has been further improved and the indications have been extended. The approach utilizes the muscle gap between the tensor fasciae latae muscle on the lateral side and the sartorius muscle on the medial side. This muscle gap allows a direct and quick approach to the hip joint with good muscle preservation. During preparation of the femur the tensor fasciae latae muscle is at risk of being damaged. The lateral cutaneous nerve of the thigh (NCFL) and its branches are also in danger of being damaged during skin incision and dissection of the subcutaneous tissue. In this article the technique, risks and current clinical results of THA using the minimally invasive direct anterior approach are described. The results from the literature, as well as own results are compared to the traditional transgluteal lateral Bauer approach and discussed. Reviewing the literature, special attention has been given to the incidence of NCFL lesions, damage of the tensor fasciae latae muscle and positioning of the cup. Especially for the latter, the general view is hindered in the minimally invasive technique.

Musculocutaneous nerve transit through a supernumerary head of the biceps brachii: implications for lateral antebrachial cutaneous and musculocutaneous nerve entrapments, diagnosis, and treatment

The lateral antebrachial cutaneous nerve (LACN) can be entrapped by the biceps tendon or bicipital aponeurosis at the cubital fossa, and the musculocutaneous nerve (MCN) can be compressed as it penetrates the coracobrachialis. Either condition can result in pain in the anterolateral elbow region and dysesthesia of the lateral forearm. These entrapment syndromes are treated either conservatively or by surgical decompression of the LACN by incision or resection of the biceps tendon or bicipital aponeurosis. We describe an unusual anatomical variation of a musculocutaneous nerve that penetrates a third head of the biceps brachii before continuing as the lateral antebrachial cutaneous nerve. Compression of the MCN by such a supernumerary biceps head could result in a pattern of symptoms similar to LACN entrapment at the elbow or MCN entrapment at the shoulder. Given that the frequency of supernumerary biceps heads has been reported to be as high as 12% in the general population, this etiology should be considered by clinicians in the differential diagnosis and treatment of these entrapment syndromes.

Lateral Antebrachial Cutaneous Neuropathy Following the Long Head of the Biceps Rupture

Lateral antebrachial cutaneous neuropathies present as purely sensory lesions, manifesting as elbow pain or dysesthetic pain over the lateral forearm. Classically, entrapment of the lateral antebrachial cutaneous nerve has been documented at the lateral edge of the biceps tendon as it exits the deep fascia in the antecubital fossa. We report a case of lateral antebrachial cutaneous nerve traction neuritis, rather than entrapment, resulting from a rupture of the long head of the biceps. The biceps displaced the nerve laterally, resulting in sensory loss and severe allodynia. The patient's symptoms were relieved with proximal biceps tenodesis.

Anatomical study of medial and lateral sural cutaneous nerve: Implications for innervated distally-based superficial sural artery flap

We report about reconstruction of the foot with an innervated distally-based superficial sural artery flap using the lateral sural cutaneous nerve. The sensation of the lateral part of the leg depends on the sural nerve (SN), and the medial part of the leg on the saphenous nerve. The border of the area between the SN and the saphenous nerve, however, is not clear. To elucidate the distribution of the medial and lateral sural cutaneous nerves, the origin, diameter, course, branches, and distributions were recorded in 40 adult cadaver lower legs. The medial and lateral nerves in all legs (n = 40) were identifiable. In one leg, the SN was a direct continuation of the medial branch, and the lateral branch ended in the middle of the lower leg. Thick (>1 mm) sub-branches from the lateral branch were identified in 26 legs. Most cutaneous branches from it ended in the middle of the sural area. We applied the innervated distally-based sural artery flap using the lateral branch in 2 cases and obtained good recovery of sensation. The lateral branch supplies most of the central sural area and is required for the innervation of the distally-based superficial sural artery flap.

A systematic review of anterolateral thigh flap donor site morbidity

The anterolateral thigh (ALT) flap is widely used in reconstruction. Its advantage over other flaps is its purported minimal donor site morbidity. The present systematic review summarizes the types of complications and their incidence with this flap. A secondary objective is to delineate factors that influence these complications and make recommendations to avoid them. Two independent assessors undertook a systematic review of the literature using multiple databases. All patients with ALT flap reconstruction for any defect were included. Donor site complications including lateral thigh paresthesia, musculoskeletal dysfunction, hypertrophic scarring, wound breakdown, infection, donor site pain, seroma, hematoma, compartment syndrome and muscle necrosis were extracted from identified articles and tabulated. Based on the number of pooled events and the number of cases performed, an incidence rate was calculated. Forty-two relevant articles were identified that included 2324 flaps. Of the 2324 flaps, the majority were fasciocutaneous (n=737), and 1303 of the flaps were used in head and neck reconstruction. The incidence of complications were: lateral thigh paresthesia (24.0%); musculoskeletal dysfunction (4.8%); hypertrophic scarring or wound dehiscence (4.8%); donor site pain (3.3%); seroma (2.4%); infection (2.2%); hematoma (0.7%); compartment syndrome (0.09%); and partial muscle necrosis (0.09%). Lateral thigh paresthesia is the most common complication. Severe complications such as compartment syndrome and muscle necrosis can occur, but are rare. Preservation of the lateral cutaneous nerve of the thigh, femoral motor nerve branches and deep fascia decreases the risk of complications. The degree of vastus lateralis disruption did not show a significant impact on musculoskeletal dysfunction.

Absence of musculocutanous nerve and its distribution taken over by the lateral cord of brachial plexus, median nerve and radial nerve

Variations in the musculocutaneous nerve are very common. But, the absence of the nerve is rare. One such case of absence of musculocutaneous nerve which was observed in a male cadaver during routine dissection is reported here. In the present case there was total absence of a normal musculocutaneous nerve. The coracobrachialis which is normally supplied by the musculocutaneous nerve was innervated by a direct branch of lateral cord of brachial plexus, whereas biceps brachii and brachialis are supplied by branches from the lateral aspect of median nerve. Lateral cutaneous nerve of forearm was arising from the lateral aspect of median nerve in common with nerve to brachialis and was partly supplying the area of innervation of a normal lateral cutaneous nerve of forearm. The remaining of its area was supplied by the posterior cutaneous nerve of forearm, a branch of radial nerve. Further , a detailed literature review about the case was done and the surgical and clinical importance of the case was discussed.

Anatomical Architecture of the Brachial Plexus in the Common Hippopotamus (Hippopotamus amphibius) with Special Reference to the Derivation and Course of its Unique Branches

The anatomy of the brachial plexus in the common hippopotamus (Hippopotamus amphibius), which has not been previously reported, was first examined bilaterally in a newborn hippopotamus. Our observations clarified the following: (1) the brachial plexus comprises the fifth cervical (C5) to first thoracic (T1) nerves. These formed two trunks, C5-C6 and C7-T1; in addition, the axillary artery passed in between C6 and C7, (2) unique branches to the brachialis muscle and those of the lateral cutaneous antebrachii nerves ramified from the median nerve, (3) nerve fibre analysis revealed that these unique nerve branches from the median nerve were closely related and structurally similar to the musculocutaneous (MC) nerve; however, they had changed course from the MC to the median nerve, and (4) this unique branching pattern is likely to be a common morphological feature of the brachial plexus in amphibians, reptiles and certain mammals.

Absence of musculocutaneous nerve with variations in course and distribution of the median nerve

Variations in the brachial plexus and its terminal branches are not uncommon. A communicating branch arising from the musculocutaneous nerve to the median nerve is a frequent variation, but complete merging of musculocutaneous nerve into the median nerve is very rare. Here, we observed variations in the origin, course and distribution of the median nerve in the left upper limb. The musculocutaneous nerve was absent. The median nerve was formed in the upper part of the arm, in front of the brachial artery. The median nerve supplied the biceps, coracobrachialis and brachialis muscles and gave the lateral cutaneous nerve of the forearm. The present report provides evidence of variation in important nerves of the anterior compartment of the arm.

Peripheral nerve block for anesthesia in patients having knee arthroplasty

Total knee arthroplasty is an effective surgical modality for osteoarthritis of the knee. Because the population is aging, the number of TKA procedures is increasing every year [1]. Both general and diverse types of regional anesthesia have been used successfully for this surgery. Femoral nerve block (FNB) was first described in 1973 and used either as a single nerve or 3-in-1 block (including the femoral nerve, the lateral cutaneous nerve, and the obturator nerve), both as an independent anesthetic modality and as an analgesic adjunct to other anesthetic techniques. In this issue of Korean Journal of Anesthesiology, Kim et al. [2] reported a study of peripheral nerve block for total knee arthroplasty. The authors conclude that femoral/sciatic nerve block with lateral femoral cutaneous nerve block can be an alternative to spinal epidural anesthesia in patients having total knee arthroplasty. They did not recommend peripheral nerve blockade as a first choice, because it is associated with a higher use of antihypertensives, analgesics, and sedatives. Nonetheless, peripheral nerve blockade showed comparable patient satisfaction and postoperative analgesia to spinal epidural anesthesia. This report is likely to create controversy because a higher use of antihypertensives, analgesics, and sedatives are associated with incomplete anesthesia. FNB does not consistently produce anesthesia of the obturator nerve [3]. The obturator nerve or sciatic nerve supplies the knee joint. Consequently, the sensation in the back of the knee can be intact after FNB. Sciatic innervations in the back of the knee is a relatively minor contribution to postoperative pain after TKA [4]. The authors argued that sparing the obturator nerve is the main cause of insufficient anesthesia. In the previous report, the addition of the obturator nerve block to FNB improves postoperative analgesia after TKA [5]. In contrast, Bouaziz et al.[6] showed that efficacy of the obturator nerve block is not sufficient as the cutaneous contribution of the obturator nerve is absent in 57% of patients. Further investigations are required to confirm the anesthetic effect of obturator nerve block for TKA. Recently, peripheral nerve blocks are widely used for low extremity surgery, but they are still less common spinal anesthesia, mainly because of the increased time and expertise required as well as the delayed recovery associated with their use. The increased time required to perform peripheral nerve block can be reduced by placing peripheral nerve blocks preoperatively in the block room. Compared with neuroaxial (spinal/epidural) anesthesia, FNB minimizes hypotension, urinary retention, pruritis, and elimi nates the risk of spinal hematoma and infection. Moreover, patients with hemodynamical instability, antiplatelet, or anticoagulant therapy can undergo a lower extremity nerve block without significant risk. The anatomical deformity caused by a degenerative change in elderly patients occasionally makes neuroaxial block inappropriate to surgical anesthesia for low extremity surgery. These benefits of lower extremity peripheral nerve block satisfy its use as an alternative anesthesia in patients undergoing lower extremity surgery. Despite these benefits, complications of peripheral nerve block limit its use for surgery. The common complications of FNB include

About the absence of musculocutaneous nerve

Introduction: Musculocutaneous nerve (C5-7) derives (90,5%) from the lateral cord of brachial plexus at the level of lateral border of pectoralis minor [1]. MC nerve pierces the coracobrachialis muscle and descends between the biceps brachii and brachialis to the lateral side of the elbow and terminates as the lateral cutaneous nerve of forearm. It supplies the biceps brachi, the coracobrachialis and the brachialis. Its terminal branch is purely sensory. Variations in the MC nerve course, distribution and termination have been reported and variably classified [2]. The most frequent variations are the presence of communicating branches with the median nerve [3] and the nerve not perforating the coracobrachialis muscle [4]. Total absence of MC nerve is less frequent (1.4 to 15%) [5]. Materials and Methods: 25 upper limbs from 13 cadavers were dissected. A skin incision was performed on deltopectoral groove and arm midline. Two fasciocutaneous flaps were raised, exposing brachial plexus and MC nerve. Results: In two specimens MC was not demonstrable. In these cases, the nerve branches to the coracobrachialis muscle and the lateral cutaneous forearm nerve originated directly from the median nerve. Conclusion: during embryogenesis MC nerve is derived relatively late, thus its absence may correspond to an incomplete differentiation of the brachial plexus. We believe this anatomical variation noteworthy because clinical procedures as plexus block or Latarjet’s procedure may be affected from MCN anomalies.

The Sensory Territory of the Lateral Cutaneous Nerve of the Thigh as Determined by Anatomic Dissections and Ultrasound-Guided Blocks

A femoral block sometimes fails to provide complete sensory anesthesia of the anterior aspect of middle and distal thigh, and a block of the lateral cutaneous nerve of the thigh (LCN) is often necessary to supplement it. The goal of this study was to demonstrate, both in the anatomy laboratory and in the clinical setting, a possible contribution of the LCN to the innervation of the anterior thigh. This was a prospective, observational study, including anatomic dissections and a clinical section in which 22 patients received an ultrasound-guided block of the LCN. The resulting area of anesthesia was determined 15 minutes later using pinprick examination. In 1 of 3 thigh dissections, we found a dominant LCN innervating most of the anterior aspect of the middle and distal thigh, areas that are usually attributed to the femoral nerve. In the clinical part of the study, 10 patients (45.5%) developed an area of anesthesia that extended to the medial aspect of the thigh and distally to the patella. Our results, coming from a small sample, seem to indicate that the LCN may contribute to the innervation of the anterior thigh in some cases. A block of the LCN could be considered when a femoral block has failed to produce the expected area of anesthesia.