Proximal humerus fracture sequelae: are corrective osteotomies still a taboo? The role of three-dimensional preoperative planning and patient specific surgical guides for proximal humerus corrective osteotomy in combination with reverse shoulder arthroplasty

Background: Symptomatic proximal humeral fracture sequelae (PHFS) represent a surgicalchallenge due to the altered bone and soft tissue morphology. The purpose of this study was to report the outcome of Multiplanar Corrective Humeral Osteotomies (MCHOs) in combination with reverse total shoulder arthroplasty (rTSA) performed following a three-dimensional (3D) preoperative planning and using a 3D-printed patient-specific surgical instrumentation (PSI) in type 1C, 1D and 4 PHFS. Methods: In this prospective monocentric study, we enrolled patients affected by symptomatic PHFS type 1C, 1D or 4 of Boileau’s classification, treated between 2018 and 2019 with rTSA associated to MCHO and followed-up at 12 and 24 months. The pre- and postoperative Constant score (CS), Visual Analogue Scale (VAS) and Disabilities of the Arm Shoulder Hand score (DASH) were recorded. All patients underwent a preoperative computed tomography (CT), then a dedicated software was used to run a segmentation algorithm on CT images. Metaphyseal bone cuts were virtually performed before surgery in all patients, and a 3D-printed PSI was used to reproduce the planned osteotomies in vivo. Results: Twenty patients completed a 2-year follow-up. The mean (± standard deviation) CS, VAS and DASH values improve from 24.3 (± 8.8), 6.5 (± 1.3), 60.7 (± 9.6) preoperatively, to 67.7 (± 11.4), 1.6 (± 0.8), 24.1 (± 13.1) points after surgery, respectively. The minimally clinical important difference for CS and DASH score was achieved in 95% of patients. No major complication was observed. One patient showed an unexplained worsening of clinical scores between the 12 and the 24-month follow-up, while in one patient bone resorption of the greater tuberosity was observed on radiographs at 2 years, with no clinical impact. Conclusion: The combination of preoperative 3D planning and intra-operative use of 3D28 printed PSI to perform MCHO as concurrent procedure in the context of rTSA in the treatment of Boileau type 1C, 1D and 4 PHFS may lead to a satisfactory clinical outcome at 2 years of follow-up. Level of Evidence: Level IV; Case Series; Treatment Study