Varied Presentation and Importance of MR Neurography of the Common Fibular Nerve in Slimmer’s Paralysis

Slimmer’s paralysis refers to a common fibular nerve palsy caused by significant and rapid weight loss. This condition usually results from entrapment of the common fibular nerve due to loss of the fat pad surrounding the fibular head. Several etiologies of common fibular nerve palsy have been proposed, including trauma, surgical complications, improperly fitted casts or braces, tumors and cysts, metabolic syndromes, and positional factors. We present 5 cases of slimmer’s paralysis in patients who had lost 32–57 kg in approximately 1 year. In 2 cases, MR neurogram of the knee demonstrated abnormalities of the common fibular nerve at the fibular head. Two patients underwent a common fibular nerve decompression at the fibular head and attained improved gait and sensorimotor function. Weight loss, diabetes mellitus, and immobilization may have contributed to slimmer’s paralysis in 1 case. Awareness of slimmer’s paralysis in patients who have lost a significant amount of weight in a short period of time is imperative to detect and treat a fibular nerve neuropathy that may ensue.

Easy Surgical Approach of the Posterolateral Corner of the Knee

Background: The anatomy of the posterolateral corner (PLC) of the knee is complex. The approach of the PLC can be a challenging and stressful surgical time. Indications: The indications are posterolateral meniscal repair, open lateral meniscus allograft transplantation, posterolateral tibial plateau fracture, and PLC reconstruction for grade III sprains. Technique Description: The skin incision is straight, realized with the knee positioned at 90° of flexion, passing slightly posterior to the lateral epicondyle, anterior to the fibular head (FH), and ending on Gerdy’s tubercle. The subcutaneous tissues are dissected posteriorly so as to expose the FH and the biceps femoris (BF) tendon. The aponeurosis of the peroneus muscles is incised vertically opposite to the anterior side of the FH. The common fibular nerve is exposed at the neck of the fibula. Metzenbaum scissors are then inserted subaponeurotically, posteriorly, and parallel to the BF tendon, superficially to the nerve. An incision is made opposite the scissor’s blades, freeing the common fibular nerve. The BF tendon is spread forward and the lateral gastrocnemius is pulled posteriorly. Metzenbaum scissors are inserted in a closed position between the lateral gastrocnemius and the posterolateral joint capsule, and then spread to create a triangular door with a proximal base. The base consists of the BF tendon, the posterior side of the lateral gastrocnemius, and the anterior side of the posterolateral joint capsule. A counter-angled Hohmann retractor can now be applied against the posterior tibial plateau to retract the lateral gastrocnemius posteriorly and medially, exposing the PLC of the knee. Results: Noble structures are easily exposed and protected. The common fibular nerve is dissected and reclined posteriorly, and the popliteus vessels are reclined posteriorly and medially, protected by the lateral gastrocnemius. Passing under the BF tendon allows a better vision of the PLC along with less constraint than passing above, as the working window is further away from the femoral insertion of the lateral gastrocnemius. Discussion/Conclusion: The present surgical approach allows a simple, safe, and reproducible exposure of the PLC of the knee.

Spontaneous intraneural hematoma of the common fibular nerve due to oral anticoagulation

Compression syndromes affecting the common fibular nerve are common and frequently caused by direct pressure upon the fibular tip region. Here, we describe a case of a 50-year-old male presenting with sudden foot drop, which had developed spontaneously. He was on oral anticoagulants due to hereditary thrombophilia (factor-V-Leiden). Neurophysiology examination revealed a common peroneal nerve lesion at the fibular tip. T1-weighted magnetic resonance imaging (MRI) showed a not further classifiable hyperintensity within the common peroneal nerve. Surgical exploration revealed a diffuse intraneural hematoma, which was not evacuated. During follow-up, the nerve function recovered almost completely. In retrospect, MRI findings indicated a hematoma supported by the history of anticoagulant medication.

Acute Improvement in Intraoperative EMG During Common Fibular Nerve Decompression in Patients with Symptomatic Diabetic Sensorimotor Peripheral Neuropathy: EMG and Clinical Attribute Interrelations

Study Aims Electromyographic (EMG) recordings of the fibularis longus and tibialis anterior muscles were performed intraoperatively during nerve decompression (ND) of the common fibular nerve (CFN) in patients with symptomatic diabetic sensorimotor peripheral neuropathy. Patient demographics and clinical attributes were compared against changes in EMG after ND and analyzed for possible correlations. Methods Intraoperative changes in CFN EMG were analyzed for correlations against sex, age, body mass index (BMI), hemoglobin A1c (A1c), and type and duration of diabetes. Results Statistically significant changes were found between EMG changes and patient attributes, but no individual correlations were established. Significant EMG improvement was observed for both men and women (p < 0.0001 and p < 0.05, respectively), age groups (4th decade: p < 0.05; 5th decade: p < 0.05; 6th decade: p < 0.01; 7th decade: p < 0.005), diabetes duration (0–9 years: p = 0.002; 10–19 years: p = 0.002; 20–29 years: p = 0.03), and for type 1 and 2 diabetes (type 1: p < 0.005; type 2: p < 0.001). EMG improvement was greater in patients with the highest BMI levels (30–34.9: p = 0.014; 35–39.9: p = 0.013; > 39.9: p = 0.043), and highest A1c levels (> 6.4%; p < 0.0001). Conclusion Although long-term clinical studies are needed, these results provide insight into which patients might benefit most from this surgery. These results also suggest that surgical ND can produce an acute improvement in nerve function for both men and women, for people with type 1 and 2 diabetes, and across a wide range of ages, BMI, A1c levels, and disease duration.

Novel Branching Pattern of the Common Fibular Nerve: Emergence of the Superficial Fibular Nerve Within the Anterior Crural Compartment

Distal to its origination from the sciatic nerve, the common fibular (peroneal) nerve divides into the superficial and deep fibular (peroneal) nerves. Whereas the deep fibular nerve continues its course into the anterior compartment, the superficial fibular nerve (SFN) usually arises near the fibular neck and projects distally within the lateral crural compartment before entering the superficial fascia proximal to the ankle. In this report, we describe a unilateral case where the SFN arises within the anterior crural compartment and remains there for the remainder of its course deep to the deep fascia of the leg. Surgeons should be aware of anomalies such as this, for example, when performing fasciotomies to avoid inadvertently damaging an anomalously placed SFN.