Enhanced Fixation of Uncemented Knee Replacement with Hydroxyapatite

Abstract: Improved cement technique by interposing less than two layers of hydroxyapatite (HA) granules between bone and bone cement at the cementing (Interface Bioactive Bone Cement : IBBC) have been performed in total knee replacement (TKR). Results of TKRs of the rheumatoid arthritis (RA) who used IBBC were evaluated. 54 knees of the RA could be followed up clinically and radiologically. As a control, clinical results of TKR with conventional cementing (Non-IBBC) were used. In IBBC cases, the appearance rate of the radiolucent lines on the tibial components and the periprosthetic osteolysis of the tibial components were significantly low. In IBBC, bone cement bound to HA mechanically immediately after surgery and HA granules bound to the bone physicochemically after bone ingrowth into the spaces around the HA granules. Thus, we believe that IBBC is a method combining the advantage of cementless HA coating and bone cement.

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Radiographic Analysis of Bone Remodeling around Hydroxyapatite Coated Femoral Stems

Authors: Rodica Marinescu, Dan Laptoiu, Iozefina Botezatu

Abstract: The study presented in the current paper was designed to investigate periprosthetic bone remodeling associated with two cementless HA coated stem models, ABG-II (Stryker) and Corail (DePuy), randomly implanted in 40 active patients at Colentina Clinical Hospital,Romania. Anteroposterior with neutral rotation and Lequesne profile radiographs of both hips were taken and several data were recorded: acetabular angle, rotation center of the hip, rotation center height with respect to the greater trochanter tip, femoral cortical thickness, cortico-medullary index at three areas (lesser trochanter (LT), 8 and 12 mm distal to LT), and osteoporosis severity according to the Singh index. The presence of osteolytic lesions in the proximal femur was assessed according to the scale proposed by Goetz in the radiographs obtained at the end of the follow-up (1 to 5 years). The radiological results showed that all stems were stable, and no evolutive radiolucent lines have been observed. We also have noticed minimal remodelling changes in 7 hips (36.61%), with minor cancellous bone densification mainly in zones 2 and 6, without cortical hypertrophy or osteoporosis. A decreased bone density in zones 1 and 7, secondary to stress-shielding, has been evident in 5 hips. Stem subsidence has been similar to that reported in literature with other hydroxyapatite coated designs.

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Radiographic Changes Observed in THA Cemented Sockets Using Bone Cement and Hydroxyapatite Granules

Authors: Jiro Tamura, Y. Asada, H. Nishida, M. Oota, M. Izeki, S. Yoshida, Y. Hira, Y. Matsuda

Abstract: The middle-term clinical and radiographic results were investigated in total hip arthroplasty (THA) cases using bone cement and hydroxyapatite (HA) granules (the interfacial bioactive bone cement technique; IBBC). 42 hip joins (39 cases) were operated between October 2005 and July 2007, and followed. The minimum follow-up was 6 years, average follow-up period was 7.0 years and average age at operation was 67 years. One revision was performed due to late infection. Average Japanese orthopaedic association (JOA) score improved from 48 to 87. Socket loosening was not observed radiographically. X-p findings of sockets demonstrated radiolucent line in the outer part of Zone 1 in 12% immediately after the operation, 24% at 2 years postoperatively. After 2 years there was no progressive change, however, improvement of radiolucent line (gap filling) with bone remodeling was observed in three cases after 3 years postoperatively.

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