Implant Design Affects Markers of Bone Resorption and Formation in Total Hip Replacement

Abstract

Concentrations of the bone resorption markers pyridinoline and deoxypyridinoline and the bone formation marker osteocalcin were measured in 24-h urine collections from 30 subjects who underwent unilateral total hip replacements for monoarticular symptomatic osteoarthrosis and 10 controls. The patient groups were divided based on the femoral implant type (cemented cobalt alloy stem, cementless porous coated cobalt alloy stem, and cementless porous coated titanium alloy stem). Urine collections were performed before surgery and then at 3, 6, 12, 24, and 36 months. There were significant changes over time in the three patient groups for pyridinoline, deoxypyridinoline, and the ratio of osteocalcin to deoxypyridinoline (p < 0.01), but the control group values did not change over time. The resorption markers tended to peak at 3 months and the osteocalcin to deoxypyridinoline ratio was more variable, having depressed values in the cementless cobalt alloy group and elevated values in the other two groups compared with baseline. The cementless cobalt alloy group had higher resorption marker levels than the cemented cobalt alloy group at 6, 12, 24, and 36 months and higher levels than the cementless titanium alloy group at all postoperative times (p < 0.05). The osteocalcin to deoxypyridinoline ratio was lower in the cementless cobalt alloy group than in the cemented cobalt alloy group at 3, 6, and 24 months and the cementless titanium alloy group at 6, 12, and 24 months (p < 0.05). For the cemented cobalt chrome group, the baseline-normalized resorption marker values at 3 months and 6 months were correlated with the severity of radiographically assessed bone loss at 36 months (0.749 < r < 0.840; p < 0.05). For the cementless titanium alloy group, baseline-normalized osteocalcin/ deoxypyridinoline ratios at 3 months and 6 months were related inversely to radiographic bone loss at 36 months (0.687 < r < 0.749; p < 0.05). Thus, body fluid markers of bone metabolism change after total hip replacement. In addition, the changes in the marker concentrations were sensitive to implant design and were correlated with subsequent stress-shielding-induced bone loss. (J Bone Miner Res 2002;17:800 -807)

Particle‐induced osteolysis is not accompanied by systemic remodeling but is reflected by systemic bone biomarkers

“…Our data suggest that localized remodeling due to particle‐induced peri‐implant osteolysis is detectable using systemic biomarkers, even though the involved region constituted <25% of the total skeletal mass in the rat model, which is roughly equivalent to the amount of bone tissue affected in humans (based on our calculations using). Our preliminary longitudinal CTX‐1 results indicate that biomarkers levels may be elevated early in the disease process, and indeed previous clinical results reported biomarker prediction of later radiographic bone loss . If future studies show that biomarkers can predict peri‐implant bone loss due to osteolysis, then early intervention to delay or avoid the need for revision surgery may be possible.…”

“…Our preliminary longitudinal CTX-1 results indicate that biomarkers levels may be elevated early in the disease process, and indeed previous clinical results reported biomarker prediction of later radiographic bone loss. 41 If future studies show that biomarkers can predict peri-implant bone loss due to osteolysis, then early intervention to delay or avoid the need for revision surgery may be possible.…”

Proximally Versus Fully Porous-coated Femoral Stems: A Multicenter Randomized Trial

“…Femoral bone loss or resorption, so-called stress shielding, around well-fixed femoral components is thought to occur around most, if not all, stem designs [12,32,34,38]. This phenomenon is reportedly exacerbated with fully coated stems [12,15,18].…”

(ii) Diagnostic plain film radiology of the failing hip replacement

“…Stress from loading through the joint is transmitted to the cortex of the femoral diaphysis through the femoral prosthesis and the cement mantle bypassing the trochanteric trabeculae, and therefore stress shielding is associated with cortical hypertrophy at the point of distal fixation. With a reduction in stress loading comes a net increase in resorption, 9 particularly in the greater trochanter, 10 which manifests as decreased mineralisation of the trabeculae and cortex on conventional radiographs. Bone mineralisation reaches a nadir at about two years after surgery and then increases to near normal levels by ten years after surgery.…”