A Novel Technique of Overlapping Distal Stump Within Femoral Allograft-Prosthesis Composite for Extensive Humeral Bone Loss in Revision Total Elbow Arthroplasty

Total elbow arthroplasty (TEA) has become a relatively common procedure for the management of arthritis or traumatic conditions of the elbow.1 The increased number of this procedure is inevitably accompanied by an increased incidence of revision procedures. The management of extensive humeral bone loss in revision total TEA remains challenging because it compromises implant stability and longevity. Depending on the location and size of the bone defect, several techniques including cancellous autograft, impaction grafting, cortical strut allograft, and allograft-prosthesis composite (APC) have been described.2–5 However, these techniques may not be enough to provide sufficient stability in such cases with extensive bone loss. Therefore, advanced techniques are necessary for the reconstruction of bone defects in revision TEA. We describe a novel technique of overlapping the distal stump within the femoral APC to address extensive humeral bone loss in revision TEA for a 74-year-old female who sustained a periprosthetic fracture of the right distal humerus with significant humeral bone loss and loosening around the humeral stem (Fig. 1).FIGURE 1: Preoperative radiographs showed a periprosthetic fracture with significant humeral bone loss and loosening around the humeral stem.TECHNIQUE The patient was placed in a supine position under general anesthesia. A previous posterior skin incision with 8 cm proximal extension was used. Without identification of the ulnar nerve, all soft tissues were retracted medially with the reflection of the triceps from the olecranon. The radial nerve was identified with complete exposure to the fracture site. Given the extent of bone loss and bone quality, which were deemed unfixable, APC reconstruction using a femoral allograft with a long humeral stem was chosen to provide stable fixation of the humeral component. After measuring the length of the bone defect, the humeral stem with the distal fragment was removed entirely. Recanalization and trimming of the distal stump were made with the removal of all polymethylmethacrylate (PMMA) using a high-speed burr. The distal humeral stump was tried to overlap within a femoral allograft, ensuring optimal contact and stability. To achieve 15 mm overlapping of the distal stump within the femoral allograft, the allograft was meticulously prepared to match the diameter of the distal humeral stump and contact completely with the anterior flange of the long humeral stem (Zimmer, Coonrad/Morrey system, Warsaw, IN) (Fig. 2).FIGURE 2: Clinical images showing preparation of APC reconstruction using a femoral allograft with a long humeral stem.Before final fixation using PMMA, trial reduction was performed to check stability and allograft impingement during elbow motion. Antibiotic-impregnated PMMA was first injected into the medullary canal of the host bone. Then the femoral allograft was combined with the distal stump. After additional cement filled the intramedullary canal of the femoral allograft, a long humeral stem with was fixed simultaneously (Fig. 3). After the triceps flap was repaired with nonabsorbable sutures through drill holes into the olecranon, layer-by-layer closure was performed.FIGURE 3: Intraoperative images showing preparation of the distal humeral stump (A) and overlapping within the femoral allograft (B). Postoperative radiographs showing revision TEA with APC reconstruction using the overlapping technique (C).EXPECTED OUTCOME Compared with traditional techniques to overcome extensive humeral bone loss in revision TEA, this technique offers technical advantages and potential clinical benefits. First, it is technically easier with time efficiency. We believe that time efficiency in revision TEA is paramount to minimizing complications. Second, it has the ability to achieve immediate implant stability without the need for additional plate fixation between the host bone and allograft. A long (8-inch) humeral stem can be fixed securely to the femoral allograft and host bone. Third, a high rate of osteointegration by overlapping the distal stump within the femoral allograft may be expected with long-term efficacy. In this study, the patients reported excellent clinical outcomes without any complications at 2 years after the surgery. COMPLICATIONS Several techniques including cancellous autograft, impaction grafting, cortical strut allograft, and APC have been described for the management of extensive bone defects in revision TEA.2–5 More recently, APC reconstruction has been proposed as an alternative option with satisfactory results.2,3,5 However, there have been reported possible allograft-related complications, including graft resorption, poor integration with host bone, nonunion, and deep infection. Renfree et al5 reported on 10 cases with APC reconstruction for revision TEA. They experienced allograft-related complications in 4 cases, although good outcomes for pain relief and stability were achieved. Mansat el al3 used an APC in 13 patients. They reported that 9 patients had complete union between the host bone and allograft, but 4 patients had deep infection that led to prosthetic removal in 3 cases. Our technique is technically easier with time efficiency. If the accurate length of bone loss to be replaced by the femoral allograft is restored, the surgical procedure becomes more straightforward, reducing operative time and complexity. We believe that time efficiency in revision TEA is paramount to minimizing complications. This technique not only simplifies the surgical procedure but also eliminates the potential risks associated with additional hardware, such as fixation failure or soft tissue irritation. The only drawback of this technique is that it is difficult to prepare the femoral allograft combined with the host bone. Preoperative planning, including measurement of the diameter of the host bone, is essential to the success of this procedure. In conclusion, this innovative technique can be an alternative option for the management of extensive bone loss in revision TEA that provides enough implant stability to early restoration of elbow function and minimize complications by reducing operative time and complexity. However, further research is needed to confirm the long-term clinical and radiographic results of this technique.