Dual Plating of Periprosthetic Distal Femur Fractures Leads to Near Anatomic Coronal Plane

Poster Title: Dual Plating of Periprosthetic Distal Femur Fractures Leads to Near Anatomic Coronal Plane

Student: Gabriel Sowards, Class of 2024

Faculty Mentor and Department: Eben Carroll, MD, Orthopaedics

Funding Source: Wake Forest Institute of Regenerative Medicine

ABSTRACT

Background: The incidence of periprosthetic distal femur fractures is rapidly rising, and this trend is expected to continue as the number of total knee arthroplasties preformed increases with the aging population. These fractures are challenging to manage for orthopaedic surgeons as they are typically the result of low energy mechanisms in elderly patients. These patients are more likely to have poor bone quality, limited bone stock, and increased comorbidities. Current fixation strategies for such fractures include lateral locked plating, intramedullary nailing, and dual implants with both lateral locked plating and intramedullary nail or dual medial and lateral locked plating. Lateral locked plating has produced some success in treating these fractures but is less than ideal due to increased non-union and complication rates. Intramedullary nailing allows for the patient to be immediately weight bearing but has been shown to result in increased rates of malunion. These shortfalls make dual implantation an attractive choice for many surgeons.

Hypothesis: We hypothesize that the dual plating method described above leads to high rate of union, low complication and malunion rates, and near anatomic coronal plane reduction.

Methods: We conducted a retrospective review of all patients who underwent dual plate fixation of a periprosthetic femur fracture at a Level I tertiary care trauma center from 2018-2020. The primary outcomes evaluated were fracture union, complications, revision surgery, sagittal plane alignment and coronal plane alignment.

Results: Of the 30 patients that underwent dual plating for a periprosthetic distal femur fracture between 2018 and 2020, nine patients were excluded from analysis due to lack of follow up. The average age of the remaining 21 patients was 81.0 years, 76.2% of whom are female. Every patient analyzed (100%) achieved union at last follow up. A total of two patients (9.5%) experienced complications. One patient (4.8%) required reoperation for the removal of a prominent screw. The other complication was an instance of wound dehiscence that resolved with local wound care. The average anatomic lateral distal femoral angle was 83.2 degrees.

Conclusions: Dual plating of periprosthetic distal femur fractures confers the patient with advantages like immediate weight bearing status, near anatomic alignment, high union rates, and low incidence of complication. This complements biomechanical studies showing that dual plating constructs provide stronger fixation than other dual implant constructs. This combination makes dual plating an appealing choice in the treatment of periprosthetic distal femur fractures. The dual plating method also obviates the need to determine the compatibility of a given knee prosthetic with a properly sized retrograde intramedullary nail. As the number of distal periprosthetic fractures increases with time, orthopaedic surgeons will rely more heavily on dual plating to obtain stronger mechanical fixation and proper anatomic coronal plane reduction.

Source of mentor’s funding or other support that funded this research: None