ABSTRACT
Objective:To explore the anatomical and clinical effects of lateral-perineal approach in treating the fracture of inferior ramus of pubis-ischium ramus.Methods:The lateral approach of the perineum was simulated on 10 side of 5 intact wet adult cadavers to determine the surface symbols of incision design and to expose the operative field of the approach and to observe the anatomical characteristics of the perineal branch of the posterior femoral cutaneous nerve and the incision of the surgical approach. Five points were selected at the incision of the approach. The distance (L 1-L 5) between each point and the body surface projection of the perineal branch of the posterior femoral cutaneous nerve was measured. A total of 11 patients, including 5 males and 6 females with an average age of 41.55±14.32 years, ranging from 18 to 62 years, were treated by this approach in clinical practice. All patients had a reduction and fixation to the fracture of inferior ramus of pubis-ischium ramus. The operation duration, incision length, intraoperative blood loss and surgical complications were recorded. The quality of fracture reduction was evaluated according to Matta radiographic criteria. The strength of the adductor was measured. The pelvic function was evaluated according to Majeed Pelvic Score at the last follow-up. Results:Anatomical studies shown that the line between the two points. One point was 4 cm lateral to the level of the apex of the pubic arch. Another point was 4 cm from the ischial tubercle on the line from the ischial tuberosity to the point that 4 cm lateral to the level of the apex of the pubic arch was the axis of the approach lateral of the perineum. Anatomical studies showed that the lateral-perineal approach could expose the range from pubic symphysis to sciatic tuberculum. The distance between the points selected at the incision of the approach and the body surface projection of the perineal branch of the posterior femoral cutaneous nerve: L 1 was 19.40±1.17 mm, ranging from 18 to 21 mm; L 2 was 16.60±2.76 mm, ranging from 10 to 20 mm; L 3 was 18.30±1.89 mm, ranging from 16 to 21 mm; L 4 was 19.20±1.93 mm, ranging from 16 to 22 mm; L 5 was 14.70±1.83 mm, ranging from 13 to 18 mm. All patients were followed up for 17.91±4.09 months, ranging from 13 to 26 months. The incision length was 8.18±0.98 cm, ranging from 7 to 10 cm. The operation duration was 59.64±12.17 min, ranging from 43 to 85 min. The intraoperative blood loss was 100 ml, ranging from 50 to 130 ml. All incisions were healed in all patients. The fractures were healed in 13.36±2.06 weeks, ranging from 10 to 16 weeks. According to Matta radiographic criteria, the quality of fracture reduction was excellent in 6 cases, good in 4 cases and fair in 1 case. At the last follow-up, the adductor muscle strength reached grade 4 in 4 patients and grade 5 in 7 patients. Furthermore, according to the Majeed Pelvic Score, the score of every patient was 86.55±9.59, ranging from 66 to 100, and 8 cases were excellent, 3 cases were good at the last follow-up. The heterotopic ossification occurred in 2 patients, the pain during intercourse occurred in 2 patients. No patient had sensory disturbance or pain in the perineal area. Conclusion:A certain safe distance is between the lateral to the perineum and the perineal branch of the posterior femoral cutaneous nerve with limited risk of injuring posterior femoral cutaneous nerve via the lateral approach of the perineum. The advantages in treating the fracture of inferior ramus of pubis-ischium ramus by this approach have concealed incision, short operation duration and less bleeding with satisfied short-term clinical effects.