Minimally Invasive Plate Osteosynthesis forProximal Humerus Fractures: A Retrospective Study DescribingPrinciples and Advantages of the Technique

The aim of this study was to evaluate the clinical and radiographic results after minimally invasive plate osteosynthesis(MIPO) for proximal humerus fractures. Potential advantages of this approach include the easier exposure of the greater tuberosityand the limited surgical dissection around the fracture site.Materials and Methods.From October 2011 to March 2016, thirty-ninepatients (32 women, 7 men) with a mean age of 64.9 years (range: 48–80) were surgically treated with the MIPO technique forproximal humeral fractures. According to Neer classification, there were 12 two-part, 24 three-part, and 2 four-part fractures and1 two-part fracture-dislocation; the AO/OTA system was also used to categorize the fractures. The Constant-Murley (CMS) andthe Oxford Shoulder (OSS) Scores were used to evaluate shoulder function.Results.Thirty-four patients were available for clinicaland radiographic evaluation at a mean follow-up of 31.8 months (range: 12–54 months). All fractures healed and no postoperativecomplications occurred. Full recovery of pretrauma activities was reported by 27 patients, while 7 patients presented mild functionallimitations. The mean absolute CMS was 75.2 (range: 55–95), themean normalized CMS was 90.5 (range: 69–107), and the meanOSS was 43.7 (range: 31–48). The only statistically significant correlation was found between the female gender and lower absoluteCMS and OSS. Radiographic evaluation revealed varus malunio‎n in 4 cases and valgus malunio‎n in 1 case, while incomplete greatertuberosity reduction was detected in 4 cases. All malunio‎ns were related to inadequate reduction at time of surgery and not tosecondary displacement.Conclusions.MIPO for proximal humeral fractures is an effective and safe surgical procedure. The limitedtissue dissection allows minimizing the incidence of nonunio‎n, avascular necrosis, and infection. The technique is not easy, requiresexperience to achieve mastery, and should be reserved for selected fracture patterns. In our experience, the main advantage of thisapproach consists in the direct access to the greater tuberosity, thus facilitating its anatomic reduction and fixation