The Usefulness of Postoperative Pinhole Bone Scintigraphy in the Assessment of Prognosis after Multiple Drilling or Vascularized Bone Graft in Patients with Avascular Necrosis of Femoral Head

Chung, Yong An; Kim, Sung Hoon; Chun, Kyung Ah; Park, Young Ha; Sohn, Hyeong Seon; Chung, Soo Kyo; Song, Mun Kab

Abstract

PURPOSE:It is important to evaluate the healing process of avascular necrosis (AVN) involving femoral head after treatment. The purpose of this study was to assess the usefulness of pinhole bone scintigraphy in the AVN of femoral head after surgery.
MATERIALS AND METHODS
We analyzed the changing pattern of pinhole bone scintigram in 21 femoral heads of 16 patients (14 lesions/11 male, 7 lesions/5 female, mean age: 39.4 yrs) before and after multiple drilling or vascularized bone grafting for AVN of the femoral head. In all patients, pre-operative scintigrams were obtained at 1 to 3 months before treatment and the first post-operative scintigrams were obtained at 1 to 3 months after treatment. All patients were followed for 2 to 4 years after operation.
RESULTS
The findings of the pinhole scintigrams were divided into three patterns: 1) curvilinear, 2) scattered spotty and 3) undetermined. The 10 of 11 lesions with curvilinear pattern had good postoperative clinical and radiological follow-up findings. However, all 6 lesions with scattered spotty pattern showed poor postoperative findings, which necessitated total hip joint replacement. Of the 4 lesions with undetermined pattern, 2 required total hip joint replacement. There was significant difference in postoperative prognosis between the curvilinear and scattered spotty patterns (p<0.05).
CONCLUSION
We conclude that the pattern of pinhole bone scintigram obtained within 1 to 3 months after multiple drilling or vascularized bone graft operation is a useful prognostic indicator in the AVN of femoral head.