Anatomical Measurement And Clinical Research Of Lateral Femoral Cutaneous Nerve Injury After Minimally Invasive Surgery Before Pelvic Fracture

Part one Anatomical measurements of the lateral femoral cutaneous nerve in the anterior pelvic ring region and the study of the extraosseous pathway through the periosteumObjective:To provide anatomical basis for the construction of minimally invasive subperiosteal pathway and to confirm the feasibility of minimally invasive subperiosteal bridging plate internal fixation,and to explore the factors of iatrogenic injury of lateral femoral cutaneous nerve by carrying out the anatomical observation and measurement of the lateral femoral cutaneous nerve in human body specimens.Methods:The lateral femoral cutaneous nerve was dissected from 20 normally antiseptic adult cadavers.The origin,routes and branches of the lateral femoral cutaneous nerve were observed,the distance between the central point of the anterior superior iliac spine and anterior inferior iliac spine and the nerve exiting the pelvis was measured.And simulated the construction of extraperiosteal channels was completed.Results:(1)It is found that there exists large variation in the anatomical position and shape when the lateral femoral cutaneous nerve goes through the pelvic nerve.The distance from the pelvic point of the nerve to the center of the anterior superior iliac spine is(1.05 + 0.86)cm and from the center of the anterior inferior iliac spine is(2.10 + 0.53)cm,according to the distance from the anterior inferior iliac spines,5.0 %(2 sides)lateral femoral cutaneous nerve to the center of anterior lower iliac spine 1.0 ~ 1.5 cm.25.0 %(10 side)lateral femoral cutaneous nerve from the anterior iliac inferior spines center 1.5 ~ 2.0 cm.The 60 %(24 side)lateral femoral cutaneous nerve was located at the center of anterior lower iliac spine 2.0 ~ 2.5 cm,while the 10 %(4 side)lateral femoral cutaneous nerve was located 2.5 cm away from the anterior lower iliac spine.(2)The lateral femoral cutaneous nerve was encapsulated by the inguinal ligament and the extensive fascia,which formed two fixation points.(3)The extraperiosteal passage was constructed with Vascular clamp.The osseous attachment from the anterior inferior iliac spine to the symphysis of the pubis was perforated and walked outside the periosteum to form a "tunnel",and the oval forceps from protruded inside the pubic tubercle.The lateral femoral cutaneous nerve moves within the tissue of the lateral plate near the anterior iliac superior spines.Conclusion:It is showed that(1)the surgical pathway was constructed smmothly,there is a large space and soft tissue interval between the lateral and lateral femoral cutaneous nerves,and it was highly feasible and safe to operate.(2)The fixation of lateral femoral cutaneous nerve by inguinal ligament and fascia lata and the high variability of neural walking was the anatomical factor of pulling and injuring the lateral femoral cutaneous nerve.Part two Clinical study of minimally invasive transperiosteal bridging plate in the treatment of anterior pelvic ring fracture and iatrogenic injury of lateral femoral cutaneous nerveObjective: The clinical data of 116 patients with anterior pelvic ring fracture and 6 patients with iatrogenic lateral femoral cutaneous nerve injury were collected to evaluate the reliability,safety and mechanism of iatrogenic injury of lateral femoral cutaneous nerve in the treatment of pelvic anterior ring fractures by minimally invasive external periosteal bridging plate internal fixation.Methods: From September 2014 to June 2017,the data of 116 patients and 6 patients with iatrogenic injury of lateral femoral cutaneous nerve were collected,and the main points of the operation were summarized.The factors of injury of lateral femoral cutaneous nerve were analyzed.The functional recovery was evaluated according to the Majeed pelvic fracture scoring system.The patients with lateral femoral cutaneous nerve injury were followed up and the pain sensitivity area of skin was evaluated by acupuncture test.The recovery was assessed according to BMRC sensory and motor evaluation criteria.Results:All 116 patients were treated with minimally invasive transperiosteal bridging plate internal fixation.The operation time of unilateral anterior ring was about 30-40 minutes,and the bleeding volume is50-80 ml.97 cases were followed up.X-ray film showed firm internal fixation and good fracture healing about 3 months after the operation.According to the Majeed score,the functional recovery after operation was evaluated: excellent results were found in 59 cases,good in 23 cases,fair in 13 cases and poor in 2 cases.Six patients with iatrogenic lateral femoral cutaneous nerve injury were followed up for 3 months to 1 year with an average of 7.4 months.According to BMRC sensory and motor evaluation criteria,3 cases were excellent combined with clinical practice(above M3S3).Conclusion: For unstable anterior pelvic ring injury,minimally invasive transperiosteal bridging plate fixation is a relatively safe,simple and effective method.However,there is still the possibility of injury to the lateral femoral cutaneous nerve,which is mostly traction injury,under the premise of stable fracture,and it can be cured through conservative treatment.Improving the understanding of applied anatomy of pelvic nerve and operating gently are conductive to avoiding the injury of medially lateral femoral cutaneous nerve effectively.