Minimally invasive internal fixation for the treatment of pelvic anterior ring injury

Objective To investigate the indication of approach, type of fixation and the clinical outcome of minimally invasive internal fixation for treatment of pelvic anterior ring injury. Methods From January 2012 to August 2016, data of 32 patients with 44 pelvic anterior ring injuries who had been treated with minimally invasive internal fixation were retrospectively analyzed. There were 22 males and 10 females with an average age of 38.2 years old (range, 20-65 years). 14 patients were injured by traffic accident, 12 patients by falling and 6 patients by crush injury. There were 4 cases of pubic symphysis diastasis, 27 fractures of anterior ring which included 12 billatral fractures and 1 combined vertical displacement of pubic symphysis associated with pubic fracture. According to AO classification, there were 3 cases in A2.3, 3 cases in B1.2, 4 cases in B2.2, 4 cases in B2.3, 2cases in C1.1, 1 case in C1.2, 5 cases in C1.3, 4 cases in C2, 6 cases in C3. There were 25 patients associated with other injuries, including brain injury in 2, thoracic injury in 17, abdominal injury in 8, urogenital system injury in 5, lumbosacral nerve plexus injury in 4 and the extremity or lumbar fracture in 19. The average period from injury to operation was 9.2 d (range, 5-32 d). 4 patients who had the pubic symphysis diastasis ,3 had pelvic anterior ring fracture medial obturator foramen and 1 combined vertical displacement of pubic symphysis associated with pubic fracture were reduced by modified Pfannenstiel incision and fixed with cannulated screws, while 36 patients with fractures of lateral obturator foramen were reduced by modified Pfannenstiel incision associated with small ilial crest incision and fixed with locking reconstruction plates, and 25 patients received the fixation of pelvic posterior ring injury simultaneously. Results The average time of operation was 44.5 min (range, 30-65 min), and the average amount of blood loss intraoperative was 56.2 ml (range, 20-150 ml). All patients were followed up successfully, with an average time of 28.2 months (range, 16-42 months). All the fractures were healed with an average time of 4.5 months (range, 3-9 months). According to Matta standard of reduction assessment, 30 fractures' reduction were excellent, 12 were good and 2 were fair, which the rate of satisfaction was 95.5% (42/44). Neither reduction loss or fixation failure nor infection occurred, and the occurrence rate of complication was 9.1% (4/44) , including one patient with fatal liquefaction and was cured 3 weeks after wound dressing, one patient with lateral femoral cutaneous nerve injury who was cured within 3 months by oral drug and 2 patients who complained discomfort of inguinal area because of the fixation prominence and were lessened by physical therapy. Conclusion Minimally invasive internal fixation can be recommended for treatment of pelvic anterior ring injury because of the advantages of less damage, safer manipulation, less complications and good prognosis. Key words: Pelvis; Surgical procedures, minimally invasive; Fractures, bone; Fracture fixation, internal