Minimum Five Year Follow-Up Study of Porous-Coated Versus Hydroxyapatite Porous-Coated Cementless Total Hip Replacement

Hwang, Sung Kwan; Lee, Doo Hee; Lim, Mu Hak

Abstract

PURPOSE
To compare the results of hydroxyapatite (HA) -coated with porous coated prosthesis for a minimum of five years.
MATERIALS AND METHODS
We reviewed radiographs of 43 patients in HA group (48 cases) and 44 patient in porous group (48 cases) that followed for a minimum of five years after primary cementless total hip arthroplasty. Average follow up period was 6.2 years in HA group and 6.8 years in porous group.
RESULTS
Harris hip score was improved to 78.1 point in porous group, 90.9 point in HA group at 6 months after surgery, but at last follwo up, 94 point in HA group, 96 point in porous group, there was no significancy. Thigh pain was noted 22.9% in porous group and 6.3% in HA group at 6 months after surgery (P=0.047) . At last follow up, thigh pain was noted 6.3% and 2.1% respectively. The mean wear of polyethylene liner was 1.36 mm in porous group and 1.72 mm in HA group (P=0.067) . Endosteal bone formation of femoral stem was noted 56.3% of porous group and 91.7% of HA group at one year after surgery, but there was 97% of endosteal bone formation was noted in both group at last follow up. Osteolysis around acetabular cup was noted 8.3% in porous group and 10.4% in HA group, and osteolysis around femoral stem was noted in 20.8%, 37.5% respectively.
CONCLUSION
The results of HA coated implant was better than that of porous group at initial, but there was no significant differency at last follow up. The difference in rate of osteolysis and polyethylene wear between both groups were not significant at the last follow up. Final acceptance must await follow-up at least of 10 to 15 years in comparison with current hip prostheses.