Minimally Invasive Approaching in Hip Surgery—An Anatomical Investigation of 20 Specimens

Background and objectives: Based on the preparation of 20 formalin-fixed anatomical cadavers, the feasibility of the anterior, minimally invasive approach to the hip joint was investigated in each side of the body. The hypothesis of the study was that the Lateral Femoral Cutaneous Nerve can be spared under the use of this approach. Materials and Methods: The anterior approach to the hip was performed via an incision of 8 cm. The position of the nerve was noticed in relation to the skin incision, and the distance was measured in millimeters. The nerves main, gluteal and femoral trunk were distinguished and investigated for injury. Results: No injury of the main trunk was noticed. The average distance of the main trunk to the skin incision was 14.9 and 15.05 mm in the medial direction, respectively (p < 0.001). Injury of the gluteal branch has to be considered at an overall rate of 40%. Conclusions: The anterior, minimally invasive approach to the hip joint can be performed without injury of the Lateral Femoral Cutaneous Nerve.

A cook with ‘burning in the thigh’ and a ‘hotspot’ in the groin!

ABSTRACT Meralgia paresthetica (MP) is a condition characterised by abnormal sensations on the anterolateral aspect of the thigh due to the dysfunction of the lateral femoral cutaneous nerve. Here, I present a case of a 64-year-old female cook who attended the General Medicine clinic with 2 months of persistent numbness and ‘burning’ sensation over the right anterolateral thigh. Subsequent physical examination revealed the diagnosis of meralgia paresthetica. The significance of good history taking and thorough physical examination in reaching the diagnosis of meralgia paresthetica cannot be overemphasized. In most typical presentations, advanced imaging and neurodiagnostic testing do not add value to confirm the diagnosis. If the clinical diagnosis is doubtful, nerve conduction study and magnetic resonance imaging may still be performed to exclude other mimicking pathologies. Increasing awareness of MP among doctors unfamiliar with this condition will prevent the ordering of excessive investigations.

Preoperative ultrasound to map the three-dimensional anatomical distribution of the lateral femoral cutaneous nerve in direct anterior approach for total hip arthroplasty

Background The postoperative complaints of hypoesthesia or a burning sensation due to lateral femoral cutaneous nerve (LFCN) injury in patients are not yet solved. The present study aimed to identify the three-dimensional (3D) distribution of LFCN using preoperative ultrasound and evaluate the rate of injury in direct anterior approach for total hip arthroplasty. Methods A total of 59 patients (28 males and 31 females, age 69.0 ± 4.6 years, BMI 24.7 ± 3.0 kg/m2) were randomly allocated to the ultrasound group and 58 patients (28 males and 30 females, age 68.5 ± 4.5 years, BMI 24.8 ± 2.8 kg/m2) were in the control group. Surgeons received the data of 3D distribution of LFCN only in the ultrasound group before surgery with respect to the direction, the depth on the skin, and the length to tensor fasciae latae (TFL). The anatomical characteristics of LFCN in the surgical region were summarized. At 1 and 3 months of post surgery, the rate of LFCN injury and abnormal sensitive area was evaluated in both groups. Results There was a significant consistency in gender, age and BMI of these two groups (P > 0.05). Based on the data from the ultrasound group, over 90% of patients had one or two branches of LFCN. LFCN always courses in the fascia layer, the depth ranged from 6.8 ± 2.6 (3.0–12.0) mm to 11.1 ± 3.4 (4.0–17.0) mm and depended on the thickness of the subcutaneous fat, and length was 3.3 ± 4.6 (− 5.0–10.0) mm at proximal part and − 2.7 ± 4.7 (− 10.0–8.0) at distal end to the medial edge of TFL. Both the rate of LFCN injury and abnormal sensory area in the ultrasound group was significantly lower than those in the control group (3.4% vs. 25.9%, P = 0.001, at 1 month; 3.4% vs. 22.4%, P = 0.005, at 3 months). Conclusions LFCN mostly courses along the medial border of TFL in the fascia layer. The 3D distribution of LFCN using preoperative ultrasound mapping could help the surgeons to evaluate the risk of injury preoperatively and decrease the rate of injury during the operation. However, some branch injuries, especially for the fan type LFCN, could not be avoided.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)—part VII, nerves of the lower limb

Objectives To perform a Delphi-based consensus on published evidence on image-guided interventional procedures for peripheral nerves of the lower limb (excluding Morton’s neuroma) and provide clinical indications. Methods We report the results of a Delphi-based consensus of 53 experts from the European Society of Musculoskeletal Radiology who reviewed the published literature for evidence on image-guided interventional procedures offered around peripheral nerves in the lower limb (excluding Morton’s neuroma) to derive their clinical indications. Experts drafted a list of statements and graded them according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus was considered strong when > 95% of experts agreed with the statement or broad when > 80% but < 95% agreed. The results of the Delphi-based consensus were used to write the paper. Results Nine statements on image-guided interventional procedures for peripheral nerves of the lower limb have been drafted. All of them received strong consensus. Image-guided pudendal nerve block is safe, effective, and well tolerated with few complications. US-guided perisciatic injection of anesthetic provides good symptom relief in patients with piriformis syndrome; however, the addition of corticosteroids to local anesthetics still has an unclear role. US-guided lateral femoral cutaneous nerve block can be used to provide effective post-operative regional analgesia. Conclusion Despite the promising results reported by published papers on image-guided interventional procedures for peripheral nerves of the lower limb, there is still a lack of evidence on the efficacy of most procedures. Key Points • Image-guided pudendal nerve block is safe, effective, and well tolerated with few complications. • US-guided perisciatic injection of anesthetic provides good symptom relief in patients with piriformis syndrome; however, the addition of corticosteroids to local anesthetics still has an unclear role. • US-guided lateral femoral cutaneous nerve block can be used to provide effective post-operative regional analgesia. The volume of local anesthetic affects the size of the blocked sensory area.

Preoperative Ultrasound to Map the Three-dimensional Anatomical Distribution of the Lateral Femoral Cutaneous Nerve in Direct Anterior Approach for Total Hip Arthroplasty

Background：The postoperative complaints of hypoaesthesia or a burning sensation due to lateral femoral cutaneous nerve (LFCN) injury in patients is not yet solved. The present study aimed to identify the three-dimensional (3D) distribution of LFCN using preoperative ultrasound and evaluate the rate of injury in direct anterior approach for total hip arthroplasty. Methods： A total of 59 patients ( 28 males and 31 females, age 69.0 ± 4.6 years，BMI 24.7 ± 3.0 kg/m2) were randomly allocated to the ultrasound group and 58 patients ( 28 males and 30 females, age 68.5 ± 4.5 years, BMI 24.8 ± 2.8 kg/m2) were in the control group. Surgeons received the data of 3D distribution of LFCN only in the ultrasound group before surgery with respect to the direction, the depth on the skin, and the length to tensor fasciae latae (TFL). The anatomical characteristics of LFCN in the surgical region were summarized. At 1 and 3 months post-surgery, the rate of LFCN injury and abnormal sensitive area were evaluated in both groups. Results： There was a significant consistency in gender, age and BMI of these two groups (P>0.05). Based on the data from the ultrasound group, over 90% of patients had one or two branches of LFCN. LFCN always courses in the fascia layer, the depth ranged from 6.8±2.6 (3.0 ~12.0) mm to 11.1±3.4 (4.0 ~17.0) mm and depended on the thickness of the subcutaneous fat, and length was 3.3±4.6 (-5.0 ~10.0) mm at proximal part and -2.7±4.7 (-10.0 ~8.0) at distal end to the medial edge of TFL. Both the rate of LFCN injury and abnormal sensory area in the ultrasound group were significantly lower than those in the control group (3.4% VS 25.9%, P=0.001, at 1 month; 3.4% VS 22.4%, P=0.005, at 3 months).Conclusions： LFCN mostly courses along the medial border of TFL in the fascia layer. The 3D distribution of LFCN using preoperative ultrasound mapping could help the surgeons to evaluate the risk of injury preoperatively and decrease the rate of injury during the operation. However, some branch injuries, especially for the fan type LFCN, could not be avoided.