OBJECTIVETo evaluate the feasibility and the clinical practicality of the design about the hollowed titanium stick supporting the femoral head and preventing it from collapsing.

METHODSFrom Jan.2003 to Jun.2007, 36 patients (46 hips) diagnosed as cystis degeneration of the femoral head were treated by surgical operation, including 20 males and 16 females with an average age of 40 years ranging from 18 to 56 years old, and the course of the disease was from 10 to 24 months (16 months on average). According to ARCO staging,there were 24 patients (34 hips) in NFH II, of which 11 hips were II a stage, 13 hips were II b stage and 10 hips were II c stage; there were 6 patients diagnosed as osteofibrous,4 patients as simple bone cyst and 2 patients as chondromyxoid fibroma. Under X-ray the percutaneous narrow core decompression and focus infection elimination were performed and supported the sclerotin under the cartilage with titanium stick. The patients were followed-up at the first, third, sixth, twelfth, twenty-fourth and thirty-sixth month after the operation. The clinical evaluation was done by X-ray and the indexes included stable, unstable and abortive. The data was analyzed by Fisher exact probility and the suviaval rate was analyzed by Kaplan-Meier suviaval curve using statistical soft ware SPSS13.5.

RESULTSThere were no unstable or failure cases on each period from the 1st month to the 12th month after the operation, indicating that the supporting effect of the titanium stick was exact during 12 months after the operation. There were unstable and failure cases from the 12th month to the 24th month after the operation, which were mainly in stage NFH II c but the comparision of the stable rate in this period and 12 months after the operation had no obvious statistical differences (P>0.05) indicating that the supporting effect of the titanium stick was feasible during the stage. One of the unstable cases deteriorated and failed but there were no new unstable cases, both the stable rate and the unstable rate had no change and the failure rate rose on the 36th month after the operation. The compar- ision of the stable rate on each period after the operation had no obvious difference (P=0.197>0.05), which indicated that the supporting effect of the titanium stick was persistent. By the difference of the etiology the three-year survival rate of the relevant NFH II c pathological changes was the lowest-70% and the survival rate of the pathological changes induced by other etiological factors was 90.2%.

CONCLUSIONThe design about the hollowed titanium stick supporting the collapsed femoral head is feasible. Using the hollowed titanium stick to support the femoral head and prevent it from collapsing is pragmatic in the clinical and the effect is positive, however, when it comes to the NFH II c pathological changes, the choice should be made discreetly.