Introduction: Minimally invasive plate osteosynthesis (MIPO) has been described as a suitable technique for the treatment of proximal humerus fractures, but long-term functional results have never been reported. The aim of this study was to describe the long-term functional outcome and implant-related irritation after MIPO for proximal humerus fractures.
Methods: A long-term prospective cohort analysis was performed on all patients treated for a proximal humerus fracture using MIPO with a Philos plate (Synthes, Switzerland) between December 2007 and October 2010. The primary outcome was the QuickDASH score. Secondary outcome measures were the subjective shoulder value (SSV), implant related irritation and implant removal.
Results: Seventy-nine out of 97 patients (81%) with a mean age of 59 years were available for follow-up. The mean follow-up was 8.3 years (SD 0.8). The mean QuickDASH score was 5.6 (SD 14). The mean SSV was 92 (SD 11). Forty out of 79 patients (50.6%) had implant removal, and of those, 27/40 (67.5%) were due to implant-related irritation. On average, the implant was removed after 1.2 years (SD 0.5). In bivariate analysis, there was an association between the AO classification and the QuickDASH (p = 0.008).
Conclusion: Treatment of proximal humerus fractures using MIPO with Philos through a deltoid split approach showed promising results. A good function can be assumed due to the excellent scores of patient oriented questionnaires. However, about one-third of the patients will have a second operation for implant removal due to implant-related irritation.
Keywords: Fracture; Long-term; MIPO; Philos; Proximal humerus; Treatment.