Three phase bone scanning and digital arteriograms for monitoring vascularized fibular grafts in femoral head necrosis.

In this prospective study the authors analysed the prognostic value of monitoring patency of the feedings vessels of the fibular graft, implanted into the femoral head to treat aseptic necrosis. In 26 patients (29 hips) we applied a three phase 99Tc-MDP Bone Scanning in the seventh postoperative day. One week later; 18 patients had a digital subtraction angiography of the lateral femoral circumflex artery and its branches. The patients were followed for average time of 22 months. The average Harris Hip Score of the affected hips improved clinically from 69.5 to 93.5. The vessels were patent prior to the wound closure. Phase I of the bone scan served as "radionuclide angiogram" and demonstrated patent vessels in all about three hips. The digital arteriograms demonstrated patent anastomotic sites in 15 out of 18 hips. Only in four of the fifteen arteriograms the vessels were visualized throughout the length of the graft. Two of the three hips with negative arteriograms have also had negative bone scans, both in patients with haemoglobinopathies. None of the patients required further surgery because of failure of the procedure. This study demonstrated that the phase I of the bone scan at the end of the first week postoperatively is very sensitive means for monitoring the viability of the graft. Digital arteriograms although more specific, were less sensitive. Early postoperative monitoring of the graft viability maintained high predictive value for the outcome of the treatment in the medium-term.