Minimally Invasive Plate Osteosynthesis (MIPO) for Treatment of Delayed or Nonunion of the Humerus Shaft Fracture: A New Technique

Introduction: The humerus shaft fracture (HSF) is a typical long bone fracture. Following non-surgical therapy, some patients experience delayed or non-union of the HSF. The most common treatment is open reduction and internal fixation (ORIF) with plate and bone graft. However, substantial tissue dissection increases radial nerve damage and delays union. Because of its minimally invasive nature, the minimally invasive plate osteosynthesis (MIPO) method may be a suitable replacement technique. MIPO helps to the protection soft tissue and nerves in the area of the fracture. A better and faster union with less tissue dissection or vascular disturbance are achieved. Methods: All patients were treated with the MIPO method using bone graft implantation. A special six-hole locking plate was used. Physical examinations and radiological studies were used to monitor the patients' progress. UCLA and the MEPS scoring system assessed shoulder and elbow function. The average follow-up period was six months. Results: The mean age of patients was 39.8 years (19-73 years). The mean fracture site distance from the elbow joint was 12.1 cm. The mean maximal final rotation was 3.3 degrees. The last rotation alignment was within normal limits. No shortening was detected. Average scores were 35 for UCLA and 100 for MEPS. Radial nerve damage was not reported. Malunion, delayed union, or nonunion did not occur. Conclusion: MIPO technique combined with bone graft causes micromotion at the fracture site, resulting in a better and faster union. Its minimally invasive nature also helps prevent iatrogenic injury to nerves and soft tissue. Less tissue manipulation and dissection help shoulder and elbow function progress more quickly and reduce the rate of malunion. We recommend using this method in delayed union and nonunion of the HSF patients for better outcomes and less complications.