Abstract
Purpose
We have compared the short-term clinical results of total hip arthroplasty (THA) using PMMA bone cement and hydroxyapatite (HA) granules (interfacial bioactive bone cement method; IBBC) with the results of conventional method using PMMA bone cement.
Materials and Methods
K-MAX HS-3 THA (JMM, Japan), with cemented titanium alloy stem and all polyethylene cemented socket, was used for THA implants. The third generation cement technique was used for the conventional THA (Group C) using bone cement (Endurance, DePuy). In the IBBC group (Group BC), the socket fixation was performed by the third generation cement technique with HA granules (Boneceram P; G-2, Olympus, Japan) according to the Ohnishi's method. In both groups, the stems were fixed by conventional cementing technique using cement gun. 76 hip joins (69 cases) were operated between April 2005 and August 2007, and followed. The group C (22 hips, 19 cases, average follow-up; 5.6 years, average age at operation; 64 years) and the group BC (54 hips, 50 cases, 5.4 years, 65 years) were investigated
Results
One revision was performed in BC group due to late infection. Japanese orthopaedic association (JOA) score improved from 42/48 to 85/87 in Group C/BC. Socket loosening was not observed radiographically. X-p findings of Group C/BC demonstrated radiolucent line in the outer part of Zone 1 in 18%/16% immediately after operation, 24%/23% at 2 years postoperatively. After 2 years there was no change in Group C, however, improvement of radiolucent line (gap filling) with bone remodeling was observed in two cases in Group BC at 3 years postoperatively.
Conclusions
The short-term clinical results of Group BC using IBBC method and Group C using conventional method were equally satisfactory. The interesting finding in Group BC case was the improvement of radiolucent line (gap filling), suggesting osteoconductive property of hydroxyapatite granules at the interface after the operations. The promising clinical results of IBBC method in the long term were expected.
