Femur shaft fracture following osteoid osteoma radiofrequency ablation

Abstract

SummaryIntroduction. Radiofrequency ablation is an effective modality in treating osteoid osteoma while avoiding the complications of an open procedure. Its complications are usually self-limited consisting mostly of local skin burns. This report presents a major complication, a femur shaft fracture following an osteoid osteoma radiofrequency ablation. The fracture occurred approximately one year after the ablation at the site of the osteoid osteoma. Discussion. Few case reports have been published regarding subtrochanteric femur fracture after ablation of an osteoid osteoma. To our knowledge this is the first report of a femoral shaft fracture following an ablation. Another unique characteristic of the presented case is the late presentation, approximately one year following ablation. Factors which may have contributed to the fracture include lateral entry point of the drill which may have weakened the femur when taking its biological and mechanical properties into account, and the fact that the patient was a soldier who was allowed to continue his military training only six weeks after the ablation. Conclusion. Radiofrequency ablation is an effective and relatively safe technique in treating osteoid osteomas, however the physician should be aware of the fracture risk involved, consider mechanical and biologic factors of the bone prior to drilling, and be very conservative when recommending return to high level activity. In addition, a close follow-up should be carried on after the procedure in order to supervise bone remodeling.

Pathologic Femur Fracture through Osteoid Osteoma after Radiofrequency Ablation: Case Report and Review of the Literature

“…Concurrently, the lateral cortex of the proximal femoral shaft and superior femoral neck experience tensile loads, placing these anatomic locations at a biomechanical disadvantage. These anisotropic properties offer an explanation for the weakening of this anatomic region after RFA, increasing susceptibility to fracture [ 13 , 18 ].…”

“…He sustained a subtrochanteric femur fracture during a long jump at the same anatomic location as his OO. Mazzawi et al reported a 20-year-old male military recruit who sustained a midshaft femur fracture while running approximately 1 year after undergoing RFA on his OO [ 18 ]. Both authors concluded that activity restrictions should be followed and patients should refrain from high-impact activities after RFA due to weaker sclerotic bone, although the duration of this recommendation remains unclear.…”

“…An uncommon but severe complication after RFA for OO is fracture, specifically of the subtrochanteric/proximal femur [ 13 , 15 , 18 ]. Only 3 reports have been documented, all in patients ranging from 12 to 20 years old, and all occurred greater than 2 months after RFA.…”

Weakening or Structural Strengthening? An Evaluation of Bone Density after MRgFUS Ablation for Treatment of Benign Bone Lesions

“…Among the ablative techniques used in Interventional Radiology, RFA is considered the gold standard in the treatment of these painful lesions, due to its technical spread and availability, uncontested reliability, and efficacy. Though it is minimally invasive, RFA brings some complications, including post-procedural bone fractures, which are rare, but disabling [ 3 , 4 , 5 ]. The main cause of post-operative fractures is controversial, whether they are related to bone weakening caused by needle access or to the effect of the thermal ablation on bone tissues.…”