Abstract
Introduction
Legg-Calve-Perthes disease (LCPD), a juvenile osteonecrosis of the femoral head (ONFH), can remain sequelae around hip joint, and results in osteoarthritis necessitating total hip arthroplasty (THA) in middle-age. THA for sequelae of LCPD needs specific concerns for anatomical deformity, leg length discrepancy (LLD), and relatively young patient's age. To date, few studies are available for the results of THA for LCPD sequelae. Moreover, there was no study for the result of Alumina-Alumina THA (Al-Al THA) in patient with LCPD sequelae, even excellent long term outcome of Al-Al THA has been documented in relatively young patients. The aim of this retrospective study is to evaluate the clinical and radiological outcome of Al-Al THA for LCPD sequelae, especially in terms of the restoration of LLD and the occurrence of complication. In addition, we compared the results of THA for LCPD sequelae with those for adult onset ONFH, in which THA is necessitated in relatively young age and excellent long term outcome has been proven after Al-Al THA.
Method
Between 1997 and 2007, 41 cementless Al-Al THA were performed in 37 patients with LCPD sequelae and followed up for mean, 10.4 years. Mean age at THA was 43.6 years. Using the propensity score matching with age, gender, and the length of follow-up as variables, 41 THAs in 37 patients were identified from 339 hips in 256 patients who underwent primary Al-Al THA for ONFH during the same period. Clinical and radiological outcomes in terms of implant survival, Harris hip score (HHS), LLD change, and perioperative complication were compared between the two groups.
Results
In LCPD group, there was no revision during follow-up period. All stems and cups were survived without osteolysis or loosening at last follow-up. HHS increased significantly from 70.9±12.9 point to 97.4±5.4 point (p<0.001). LLD decreased significantly from 2.0±1.2 cm to 0.2±0.9 cm. (p<0.001). Fourteen intraoperative femoral cracks occurred. One patient showed peroneal nerve palsy after surgery. There was one patient with deep vein thrombosis without pulmonary embolism. In ONFH group, there was also no revision during follow-up and all implant was radiologically stable without evidence of osteolysis or loosening. HHS increased significantly from 44.9±21.4 point to 96.6±4.6 point (p<0.001). LLD decreased significantly from 0.5±0.8 cm to 0.1±0.9 cm. There were 6 intraoperative femoral fractures. Also, there was 2 more postoperative periprosthetic fractures after trauma and 1 postoperative dislocation. Even the implant survival was not different between two groups, LCPD group showed higher rate of overall complication (p=0.04) and intraoperative femoral fracture (p=0.027) than ONFH group.
Conclusion
Outcomes of Al-Al THA in patients with sequelae of LCPD were comparable to those in patients with ONFH clinically and radiologically. LLD was restored after THA without troublesome neurologic complication in both groups. Although high rate of intraoperative femoral crack was revealed in LCPD group, fracture union was achieved in all hips without stem loosening. As with ONFH, Al-Al THA may be a reliable treatment option for the patients with LCPD sequelae.
