Metabolic development of necrotic bone in the femoral head following resurfacing arthroplasty. A clinical [18F]fluoride-PET study in 11 asymptomatic hips

Acta Orthop. 2012 Feb;83(1):22-5. doi: 10.3109/17453674.2011.641108. Epub 2011 Nov 23.

Abstract

Background and purpose: One concern regarding resurfacing arthroplasty is the viability of the diminished femoral head and the postoperative risk of collapse, or a femoral neck fracture. (18)F-fluoride positron emission tomography (F-PET) enables us to assess bone viability despite there being a covering metal component. By F-PET studies, we recently showed the absence of metabolism in the remaining part of femoral heads, 1-4 years after surgery in 11 of 46 consecutive cases. We now present the further development of bone metabolism in these 11 cases.

Patients and methods: 10 patients (11 chips) with previously shown loss of femoral head metabolism were evaluated by radiography and repeated F-PET scans, 3-6.5 years after surgery. The size of the area with low (18)F-fluoride PET uptake in the femoral head was compared to that in earlier PET images.

Results: No patients had any clinical symptoms; nor was any necrotic bone area visible in plain radiographs. On F-PET scans, 2 patients showed a diminished area with low uptake, 4 were unchanged, and 5 had enlarged areas.

Interpretation: Bone metabolism surrounding a volume of bone with no metabolic activity changes dynamically even 5 years after surgery. The presence of bone with minor uptake of F-tracer, indicating low or no bone metabolism, with further progression in 5 of 11 cases leads us to conclude that resurfacing THA should be used restrictively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthroplasty, Replacement, Hip / adverse effects*
  • Arthroplasty, Replacement, Hip / methods
  • Female
  • Femur Head Necrosis / diagnostic imaging*
  • Femur Head Necrosis / metabolism*
  • Fluorine Radioisotopes / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals / metabolism

Substances

  • Fluorine Radioisotopes
  • Radiopharmaceuticals