Abstract
Introduction: It is very important to evaluate the healing process in the femoral head after free vascularized fibular graft (VFG) in osteonecrosis of the femoral head (ONFH). Bone scintigraphy combined with a pinhole collimator, which is simple and not expensive, is used for very high resolution images of small organs, such as thyroid and certain skeletal regions. The purpose of this study was to assess the changes using pinhole bone scintigraphy in ONFH after VFG.
Materials and Methods: Changes of Tc-99m-HDP pinhole bone scintigraphy were analyzed in 22 cases of ONFH which were treated with VFG and had satisfactory results in patient evaluations at least 2 years after surgery. Harris Hip Scores were 90 points or more; and femoral head collapse was less than 2 mm.
Results: The results were: (1) At 1 week, the pinhole image showed no significant change in cold area but two linear RI uptakes corresponding to the fibular graft were noted. (2) At 3 months, localized hot uptakes just above the tip of the graft were observed in 17 cases (77.2%), and diffuse increased uptake surrounding the cold area were observed. (3) At 6 months, localized hot uptake were increased in size and replaced cold areas and delineated the shape of the superolateral aspect of the femoral head. (4) At 1 year, increased RI uptake of the superolateral aspect of the femoral head expanded medially in all cases. (5) After 2 years, cold areas faded away in 18 cases (81.8%).
Discussion: In conclusion, the authors believe that the Tc-99m-HDP pinhole bone scintigraphy is an excellent method to delineate the healing process in ONFH after VFG.
The abstracts were prepared by Michael A. Mont, M.D. and Lynne C. Jones, Ph.D. Correspondence should be addressed to L. Jones at Good Samaritan Prof. Bldg., Suite 201, 5601 Loch Raven Blvd., Baltimore, MD 21239
