An uncommon complication of all types of arthroplasties is a periprosthetic fracture ^[1,2]. Although they are less frequent in shoulder arthroplasties, they nonetheless provide a challenge in patient care. Total shoulder arthroplasty (TSA) and reverse TSA (RTSA) have become mainstay treatment options for various shoulder pathologies, including osteoarthritis, rotator cuff arthropathy, massive rotator cuff tear, and certain proximal humeral fractures ^[3,4]. Periprosthetic fractures develop in relation to prosthetic implants, usually in the TSA components. The incidence of periprosthetic fracture is reported as 0.6–3% of patients with TSA ^[5]. TSA and reverse shoulder arthroplasty (RSA) have revolutionized the treatment of complex shoulder pathologies, including osteoarthritis, massive rotator cuff tears, and proximal humerus fractures ^[6,7]. RSA, in particular, is often chosen for rotator cuff-deficient shoulders. However, in elderly patients with poor bone quality, RSA may be associated with increased risk of complications such as early loosening, scapular notching, instability, or infection ^[7,8,9]. Although post-operative periprosthetic humeral fractures are rare, they are becoming more common as the population ages and these procedures become more common . The most common location of the fracture is the humerus. Periprosthetic humeral fractures most often occur intraoperativokely but can also develop postoperatively, especially in osteoporotic bone. The Wright and Cofield classification is commonly used to categorize these fractures based on the location in relation to the humeral stem. Hamada classification further guides the assessment of fixation failures in the presence of prosthetic components ^[10]. Periprosthetic fractures often present surgeons with difficult management decisions and, in cases of surgical management, technical challenges. The reported incidence of periprosthetic humeral fractures following shoulder arthroplasty varies greatly (1.2–19.4%) [5-8]. Management options vary from conservative treatment to revision arthroplasty or surgical fixation ^[6]. options such as vascularized fibular grafts traditionally used in long bone non-unions may offer superior mechanical stability and biological integration.

An 80-year-old female patient with a known history of systemic hypertension and severe osteoporosis presented to the emergency room (ER) with a history of a fall and was diagnosed to have a periprosthetic fracture of the right humerus (Figure 1) and an extrarticular fracture of the left distal radius.

2.5 years back, she had undergone a RTSA of the right shoulder for stage IV Hamada rotator cuff tear arthropathy with excellent results. On initial evaluation, she also had a high radial nerve injury of the right upper limb. She underwent open reduction and internal fixation of the right humerus with cortico-cancellous bone grafting (Figure 2a,b), exploration of the radial nerve(Figure 2c) via a standard posterior approach. The radial nerve was physically intact with a perineural hematoma, which was evacuated at surgery.

A standard open reduction and internal fixation was utilized to treat the contralateral distal radius fracture. Three weeks later patient presented with a history of a trivial trauma (twisting injury while applying an arm sling) and, on evaluation, was diagnosed to have a displaced fracture with a failed implant (Figure 3a,b).

The patient was admitted for further evaluation and surgical management. Upon clinical examination at the time of admission, the patient was alert, oriented, and afebrile, with stable vital signs. Local examination of the right upper limb revealed tenderness and a well-healed surgical scar with radiographic evidence of periprosthetic fracture and implant failure. Given the complexity of the case, she was initially managed with immobilization using splintage, along with standard analgesics and supportive medical care. After thorough preoperative counseling, including expected outcomes and the importance of post-operative physiotherapy and follow-up, informed consent was obtained from the patient and her family. A combined orthopedic and vascular surgical procedure was planned.

Surgical technique

The patient was positioned supine with a side arm table. An extended anterolateral approach combined with a medial incision for additional exposure of the brachial vasculature was chosen after discussion with the vascular surgeon so as to enable safe and effective vascular anastomosis between the brachial vessels and the peroneal vessels of the graft. The implant (locking compression plate [LCP] 4.5 mm) was found to be completely backed out (Figure 3 c) from the distal fragment with stripping of all four locking screws. The radial nerve was completely isolated from the plate, protected, and a safe exit of the entire implant was carried out. A 10 cm segment of fibula with an associated vascular pedicle was selected, shaped appropriately, and interposed in the gap between reduced proximal and distal fragments in such a way that good contact is made between the host bone and the graft. The remaining portion of the fibula was split longitudinally and used on either side of the construct to augment the fixation. Finally, a 4.5 mm LCP was used along with an encirclage wire system to complete the procedure. The case was handed over to the vascular surgeon to complete the microvascular anastomosis. Good blood flow in the graft was observed post-anastomosis. Fluoroscopy images showed near anatomical reduction of the fracture with a well-placed fibula graft (Figure 4a, b) with excellent contact all over.

The fixation and the prosthesis were checked for stability and were satisfactory. Routine wound lavage and layered closure were achieved. Postoperatively, the limb was immobilized in an arm sling pouch, and the patient had an uneventful recovery. Postoperatively, she was hemodynamically stable, afebrile, and displayed no signs of wound infection, deep vein thrombosis, or neurological deficits. She was advised to continue wound care. Aggressive medical management of osteoporosis (teriparatide) was continued into the post-operative phase. Early passive mobilization of the elbow, wrist, and fingers to prevent stiffness and aid in functional recovery was initiated on the 1^st post-operative day and continued for 4 weeks. Active assisted mobilization was started from the 5^th week, and later active mobilization was allowed from the 9^th week. Serial follow-up X-rays showed progressive union of the fracture, with complete healing observed at 3 months. At 3 months from the procedure, the patient had complete recovery of the radial nerve palsy, an active full range of motion of the shoulder and elbow, with comfortable activities of daily living (ADL) (Figure 5 a,b,c). At the final follow-up of 3 years, comfortable ADL were well maintained.

Post-operative periprosthetic humeral fractures are much rarer than intra-operative fractures. Similar to how the Vancouver method is applied to the classification of periprosthetic proximal femoral fractures, the fractures can be categorized according to their anatomy and implant stability. The categorization is somewhat different from the intra-operative periprosthetic fracture classification. The tuberosities are the site of type A post-operative periprosthetic humeral fractures. Fractures of type B happen at the stem. Subtypes B1 spiral fractures with a stable implant, B2 short oblique fractures at the tip of the stem with a stable implant, and B3 fractures around the stem with an unstable implant are the three categories into which these can be divided. Type C fractures happen far from the stem’s tip ^[10]. Our case demonstrates the distinctive function of vascularized fibular grafting as a rescue technique in an elderly osteoporotic patient experiencing fixation failure after a periprosthetic fracture following RTSA. The choice to use a vascularized fibular graft was influenced by the patient’s compromised bone quality and the previous construct’s mechanical instability, highlighting the increasing agreement in the literature supporting biological enhancement in complicated revisions. Studies have indicated that non-vascularized bone grafts frequently fail in patients with osteoporosis because of inadequate integration and insufficient blood supply, especially in revision situations. On the other hand, vascularized fibular grafts offer strong structural support and osteogenic ability with proven efficacy in long bone non-unions, especially in cases of failed fixation or infection [2-8]. Our case reflects these findings, highlighting its usefulness in periprosthetic fractures where internal fixation by itself is inadequate. The failure of fracture fixation in the context of RSA has been insufficiently reported. Another study highlighted that RTSA, although beneficial for rotator cuff arthropathy, tends to experience complications in osteoporotic individuals, particularly when facing further trauma [8-10]. Our case adds support to this, as the initial fixation did not succeed even with correct surgical technique, indicating that mechanical devices by themselves might be inadequate in hosts with severe osteoporosis. With the increasing rates of shoulder arthroplasty in the older population, upcoming research needs to emphasize prospective assessment of vascularized grafting techniques in upper limb periprosthetic fractures to create standardized guidelines and to enhance the surgical criteria. Alternative approaches, such as vascularized bone grafts, ought to be included in the surgical toolkit for specific situations.

This case highlights the challenges of managing periprosthetic fractures in osteoporotic patients with a history of multiple orthopedic interventions. The multidisciplinary approach, timely surgical intervention, and structured post-operative care, including physiotherapy and medication, were critical in ensuring a stable recovery.

In elderly osteoporotic patients with complex periprosthetic humeral fractures and failed prior fixation, a vascularized fibular graft provides both biological and mechanical superiority. This technique offers a viable salvage option, promoting rapid union and restoring function where conventional methods are prone to failure. A successful outcome hinges on a multidisciplinary surgical approach and aggressive postoperative medical and rehabilitative management.