Single-Stage Bilateral Reverse Shoulder Arthroplasty for a Bilateral Four-Part Fracture Dislocation of the Proximal Humerus in an Elderly Patient: A Case Report.

Proximal humerus fractures (PHFs) are a common type of fracture in adults. Although PHFs are common, bilateral presentation is extremely rare. Most PHFs are treated conservatively. In this report, we describe a 69-year-old right-hand-dominant male patient who was involved in a high-impact motor vehicle accident (MVA). The patient's upper limbs were in a fully extended position while he was holding the driving wheel, where he sustained a side impaction to the car by a hard object that caused bilateral four-part PHF with dislocation, which was confirmed on radiological investigations. The orthopedic surgery team believed that surgical treatment was necessary and ideal for these bilateral fracture dislocations, specifically bilateral reverse total shoulder arthroplasty (RTSA). This is due to multiple factors, including the risk of humeral head avascular necrosis (AVN), the patient's advanced age, low demand, poor bone stock, osteoporosis, and a non-fixable fracture pattern. The patient underwent a single-stage bilateral RTSA procedure, which was well tolerated. He was optimized postoperatively. The post-operative X-ray showed good and satisfactory implant positions and orientation. Functional assessment using the Constant-Murley Score (CMS) and Disabilities of the Arm, Shoulder and Hand (DASH) score were calculated at three-months follow-up (right-left: 50-60 and 41-14, respectively), at five-months follow-up (right-left: 34-66 and 38-14, respectively), and at eight-months follow-up (right-left: 40-68 and 24-7.5, respectively). Follow-up X-rays revealed good tuberosities healing, and no loosening or scapular notching. In addition, pain was assessed on a numerical rating scale (NRS), which demonstrated fast pain relief. Short-term follow-up with the patient demonstrated that he was satisfied with the surgery, especially the left side with a pain score on the NRS of one. We selected to share our experience of this complex case with our peers in the field of orthopedic surgery worldwide so that such a procedure could be implemented in similar cases to ensure satisfactory outcomes following bilateral four-part PHF with dislocation.