Case Series: Treating Fractures with Revision Total Knee

Poster Title: Case Series: Treating Fractures with Revision Total Knee

Student: Emily Sparks, Class of 2024

Faculty Mentor and Department: John Shields, MD; Department of Orthopaedic Surgery

Funding Source: Department of Medical Education, Wake Forest School of Medicine

ABSTRACT

Background: Total knee arthroplasty (TKA) is one of the most common and successful procedures done today. Excellent functional outcomes are seen with patients undergoing TKA for arthritis, with the greatest improvement found in patients with severe disease. Periprosthetic fractures occur around total knee components, most commonly the supracondylar femur with a rate of 0.3-2.5%, with the tibia being less common. The primary goal of periprosthetic management is to allow patients to regain function and have early mobilization to assist the healing process. When such fractures occur in the absence of total knee replacements, management is much more straightforward, however severe ipsilateral arthritis may impede early mobilization and fracture healing. Fractures are managed by conservative treatment, intramedullary nailing (IMN), and open reduction and internal fixation (ORIF). Patients who have long bone fractures along with arthritis in their knee present a difficult problem as arthritic pain limits the ability of a patient to bear weight, which hampers their ability to heal the fracture. It is estimated that in 1.9% to 10% of all long bone fractures, delayed unions and non-unions occur for a variety of reasons. Mechanical load is considered one of the most important factors in regulating bone mass. TKA can be a mechanical solution to a biological problem, allowing fixing both long bone fractures and correcting bone deformities due to fracture. Additionally, evidence has shown that intervention with TKA is effective and successful for reducing pain from arthritis and improving physical function.

Hypothesis: Long bone fractures are a common orthopaedic injury. When presenting in conjunction with ipsilateral knee osteoarthritis, rehabilitation and bone healing can be impaired secondary to limited weight-bearing. One can manage both pathologies with long-stemmed revision total knee components. The average improvement in our knee outcome scores via pre-operative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR.) and one-year post-operative KOOS, JR. is 44.37. We present four cases as a proposal of a novel way to treat these injuries in an effective way.

Methods: retrospective case-series

Results: When a patient presents with a long bone injury, there is a focus on managing the fracture. When the patient’s other musculoskeletal co-morbidities impede early mobilization, fracture healing can be impacted. One should consider revision TKA with long-stemmed components for management of ipsilateral knee arthritis which can inhibit early weight-bearing, and simultaneously manage the long bone fracture.

Patient outcomes were reported pre-operatively and post-operative via the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) survey seen in Table 1. 

Patient outcomes showed excellent improvement with an average difference in KOOS, JR. score of 44.37 one year post-operatively versus pre-operatively. All four patients underwent total knee arthroplasty with long-stemmed components to management their knee osteoarthritis and simultaneous long bone pathology. For all patients, their anteroposterior and lateral radiographs demonstrated well-fixed and aligned femoral and tibial components, along with healed fractures. On physical exam, all patients had improved satisfaction and range of motion at 1-year follow-up.

Conclusions: Ipsilateral knee osteoarthritis with concurrent long bone fractures is a complicated problem that presents a challenge to surgical management. Here we present case examples of a novel way to treat both pathologies simultaneously with TKA with long stem prosthetic for fracture fixation. Treating patients in such a way improves patient outcomes, mobilization, and system cost.

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