Metal-To-Metal Total Hip Arthroplasty For FHN Treatment A Follow-Up Assessment

Objective: To discuss the biocompatibility between the implants and the hosts in patients underwent metal-to-metal total hip arthroplasty for treatment and observe the functional recovery of FHN (avascular necrosis of femoral head) and hip articulations。Patients and Methods:1. Patients :Between January 2006 and February 2009, a total of 128 hips in 90 patients with advanced osteoarthritis secondary to FHN underwent the metal-to-metal total hip arthroplasty. Among the patients, 60 were male and 30 were female, with their ages ranging from 25 to 65 years and an average age of 42 years. The bilateral arthroplasty was performed in 38 patients and the unilateral arthroplasty in 52 patients. Hip arthroplasty prostheses were offered by Zimmer Company (Huntington, Indiana, USA)o Metasul have the Metasul(?) LDH(?) (large diameter head). The Metasul(?) LDH(?) are available from 38 to 60mm and must be used in combination with the Durom acetabular componentThe Durom acetabular is 4-mm-thick . In order to optimize restoration of joint kinematics, the Metasul(?) LDH(?) system has been developed with 4 neck lengths. Titanium vacuum plasma sprayed coatings have been associated with reliable bone on-growth allowing durable secondary fixation. Range of motion varies from 144°to 168°based upon the determined size of the acetabular component and the mating large diameter head.2. Method: total hip arthroplasty was performed with a anterolateral incision.Antiseptic treatment and systemic healing exercise was regular after operation.With a follow-up for 6-30 months, therapeutic effect was evaluated by Harrisgrade system and X-ray examination.Results: All the patients were followed up for 1 month to 38 months(averaged 18 months). The Harris scores after operation from 49 points preoperatively to 95 points postoperatively. The differences between peroperation and postoperation were significant. No patient in which hip dislocation happened.Conclusion: Metal-to-metal total hip arthroplasty has excellent early effects on young and active patients. Thearthroplasty potentially offers the ultimate bone preservation of hip articulation function in patients, without specific biocompatibility.