54-year-old man with comminuted distal femur fracture
A 54-year-old man with a past medical history of type 1 diabetes mellitus, heart failure and renal transplant presented to the ED after having a mechanical fall resulting in pain, deformity to the right knee and inability to weight-bear.
At baseline, the patient was ambulatory using a walker for short distances. For long distances he was reliant on his motorized wheelchair. He could perform independent transfers. On the day of the injury, he was on his motorized wheelchair when its battery reportedly failed causing him to fall forward directly onto his right knee. On examination, the knee was significantly swollen and deformed, and the injury was closed.
Radiographs and CT scan (Figure 1) demonstrated a complete intra-articular distal femur fracture. Of note, there was a coronal plane fracture line in the lateral condyle and the metaphyseal fracture line was oblique with an apex at the proximal aspect of the medial distal femur.
Source: Mejbel Alajmi, MD; Aresh Sepehri, MD, FRCSC; and David J. Stockton, MD, FRCSC
What are the best next steps in the management of this patient?
See answer below.
Open reduction and internal fixation
The patient was placed in a knee-immobilizing soft splint. After medical optimization, including consultation with the transplant medicine service, the next step in the management of this patient was to perform an open reduction and internal fixation with the goal of restoring joint congruity and alignment with rigid fixation to allow for early rehabilitation. Consideration of a construct that permitted early or immediate weight-bearing was considered in this patient as prolonged immobilization may result in numerous adverse outcomes, including prolonged hospital stay, immobility-related adverse events and long-term ambulatory limitations.
The challenges with this case were the intra-articular comminution and poor bone quality as a result of osteoporosis and chronic kidney disease. Due to his bone quality and the goal of immediate mobilization, a dual implant construct was considered. The fracture orientation of the metaphysis with the fracture extending proximally on the medial femur made it amenable to a reliable anatomic reduction and application of a medial anti-glide plate. Given that the fixation of the intra-articular fracture elements would have increased screw traffic in the distal segment, insertion of a retrograde femoral nail would have been more challenging. Following these important preoperative considerations, the final decision was made to perform medial and lateral plate fixation for this injury.
Surgical procedure
The patient was placed supine and general anesthesia was administered. The right lower limb was prepped and draped in the regular fashion. A tourniquet was used, and lateral and medial incisions were marked. A lateral parapatellar arthrotomy was made, and a subvastus approach was used to access the comminuted joint fragments and metaphyseal aspect of the fracture. Subsequently, a medial subvastus approach was performed while retracting the adductor magnus posteriorly. The femoral artery was proximal to the proximal-most end of the medial approach to the distal femur and was not encountered. Care was taken not to strip the anterior femur of its soft tissue attachments between the two incisions.
The articular block was first reduced using a combination of reduction clamps, K-wires as joysticks and a periarticular reduction clamp (Figure 2). The Hoffa fragment in the lateral distal femoral condyle was reduced with a reduction clamp and fixed with a 2.7-mm anterior-to-posterior lag screw. The articular block was fixed with two 2.7-mm lag screws.
After reducing and fixing the articular surface, converting the fracture from an AO/OTA 33C to a 33A type, the articular block was reduced to the femoral shaft using the medial fracture line (Figure 3). A 3.5-mm recon plate was used in anti-glide mode over the posteromedial apex of the metaphyseal fracture. A 12-hole variable angle distal femur locking plate was applied to the lateral femur with locking screws distally and cortical screws proximally. The patient was ranged from 0° to 110° intraoperatively with stable fixation. The wounds were irrigated thoroughly and closed in layers. The patient was placed in a hinged knee brace, locked in extension at nighttime and was permitted to proceed with gentle range of motion during the day.
Follow-up
At the most recent follow-up, 8 months postoperatively, he reported that he is back to his baseline level of mobility. All of his wounds healed without infection. He is able to range his knee from 0° to100°.
Radiographs demonstrated maintained reduction, alignment and complete bridging of fracture callus (Figure 4).
Discussion
Distal femur fractures have a bi-modal distribution with younger patients sustaining these injuries following high-energy mechanisms while patients older than 65 years typically sustain these fractures following low-energy mechanisms. Distal femur fractures have an 11% to 20% rate of nonunion and loss of fixation. The incidence of distal femur fractures is increasing as patient longevity is also increasing. Osteoporosis combined with a frail patient population introduces unique challenges when managing these injuries. The primary goals of surgical intervention are to provide rigid fixation to restore joint congruency and mechanical alignment, and to facilitate bony healing and early ambulation.
Numerous fixation options have been developed and applied for the fixation of these fractures, including fixed-angle blade plates, lateral locking plates and retrograde intramedullary (IM) nails. The fixed angle blade plate has largely been replaced by the lateral locked plate as the primary method of fixation for distal femur fractures. Retrograde IM nail fixation may be preferable in A type distal femur fractures with extensive metaphyseal comminution, as it stabilizes the fracture closer to the mechanical axis of the limb and is not as susceptible to cantilever bending seen in some lateral locked plate constructs. However, they are limited when multiple articular fracture lines must be addressed. Lateral locking plating is the preferred construct for such situations. Michael Zlowodzki, MD, and colleagues compared the three options biomechanically and found that lateral locking plates were superior in terms of distal stability in osteoporotic bone and intra-articular comminution.
Despite that, lateral locking plates have been associated with failure, malalignment and nonunion. This led to the introduction of dual implants, either with dual plating or nail-plate constructs. Biomechanical studies have demonstrated that dual implant constructs have increased load to failure compared with lateral locked plating alone. These techniques are sometimes employed in the geriatric population to facilitate early mobilization without risking implant failure in osteoporotic bone. For this case in a physiologically older individual, because of the oblique metaphyseal fracture line in combination with an intra-articular fracture pattern, dual plating was performed with good effect.
Key points
- Distal femur fractures in older patients often present with comminution and poor bone quality which might be challenging to manage.
- Multiple options are available for the management of these fractures. Careful preoperative evaluation and planning should be carried out before deciding on the best possible option.
- Dual plating shows superior results when compared with single plating for comminuted intra-articular fractures in osteoporotic bone.
- References:
- Court-Brown CM, et al. Injury. 2006;doi:10.1016/j.injury.2006.04.130.
- Fontenot PB, et al. J Orthop Trauma. 2019;doi:10.1097/BOT.0000000000001591.
- Gwathmey WF, et al. J Am Acad Orthop Surg. 2010;doi:10.5435/00124635-201010000-00003.
- Hake ME, et al. J Am Acad Orthop Surg. 2019;doi:10.5435/jaaos-d-17-00706.
- Lee C, et al. J Orthop Trauma. 2023;doi:10.1097/BOT.0000000000002516.
- Zhang GX, et al. EFORT Open Rev. 2024;doi:10.1530/eor-23-0160.
- Zlowodzki M, et al. J Orthop Trauma. 2004;doi:10.1097/00005131-200409000-00004.
- For more information:
- Mejbel Alajmi, MD; Aresh Sepehri, MD, FRCSC; and David J. Stockton, MD, FRCSC, can be reached at the department of orthopedics at the University of British Columbia in Vancouver, British Columbia, Canada. Alajmi’s email: mejbelalajmi@gmail.com.
- Edited by Nicole Rynecki, MD, and Harold I. Salmons, MD. Rynecki is a chief resident in orthopedic surgery at NYU Langone. She will be pursuing a sports medicine fellowship at Hospital for Special Surgery following residency completion. Salmons is a chief orthopedic surgery resident at the Mayo Clinic. He will be pursuing an adult reconstruction fellowship at Hospital for Special Surgery following residency completion. For more information on submitting Orthopedics Today Grand Rounds cases, please email orthopedics@healio.com.
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