Li Ming G, Thorsen Kim, Nilsson Kjell G
Department of Orthopaedics, Umeå University, 90185 Umea, Sweden.
Arch Orthop Trauma Surg. 2004 Jul;124(6):404-9. doi: 10.1007/s00402-004-0695-0. Epub 2004 May 20.
Whether biochemical markers of bone metabolism can be used in assessing the conditions of implant fixation is unknown. In this study, the serum levels of three bone markers were measured prospectively in patients undergoing total knee arthroplasty (TKA) to determine if patients with different fixation conditions of the tibial component showed any differences in the levels of the markers.
The fixation of the tibial component in 40 knees (40 patients, 14 male and 26 female, average age 71 years) was assessed by radiostereometric analysis (RSA), and based upon the pattern of migration, implants with stable fixation ( n=25) and potentially unstable fixation ( n=15) were identified. Serum levels of carboxyterminal propeptide of type I procollagen (PICP), osteocalcin (OC) and cross-linked carboxyterminal telopeptide of type I collagen (ICTP) were assessed and compared between the two fixation groups. Blood samples were obtained preoperatively (baseline) and repeated postoperatively at 1 week, 3, 6, 12, and 24 months.
The baseline levels of the markers were statistically the same ( p>0.05) between the two fixation groups. Postoperatively, ICTP levels in the unstable group were significantly higher than in the stable group from 6 to 24 months ( p=0.02). Levels of OC in the unstable group were higher at 12 and 24 months compared with the stable group, reaching statistical significance only at 12 months ( p=0.03). No difference in the levels of PICP was found between the two groups.
The findings indicate a more active bone turnover probably at the bone-cement/implant interface in knees with potentially unstable fixation. It reveals the potential value for biochemical markers in monitoring implant fixation and aseptic loosening and suggests a possibility for improving implant fixation by drugs which inhibit osteolysis.
骨代谢的生化标志物是否可用于评估植入物固定情况尚不清楚。在本研究中，前瞻性地测量了接受全膝关节置换术（TKA）患者的三种骨标志物血清水平，以确定胫骨组件固定条件不同的患者在这些标志物水平上是否存在差异。
通过放射立体分析（RSA）评估40例膝关节（40例患者，14例男性和26例女性，平均年龄71岁）中胫骨组件的固定情况，并根据移位模式确定固定稳定的植入物（n = 25）和可能不稳定的植入物（n = 15）。评估并比较了两组固定情况下I型前胶原羧基末端前肽（PICP）、骨钙素（OC）和I型胶原交联羧基末端肽（ICTP）的血清水平。术前（基线）采集血样，并在术后1周、3个月、6个月、12个月和24个月重复采集。
两组固定情况下标志物的基线水平在统计学上相同（p>0.05）。术后，不稳定组在6至24个月时的ICTP水平显著高于稳定组（p = 0.02）。不稳定组在12个月和24个月时的OC水平高于稳定组，仅在12个月时达到统计学显著性（p = 0.03）。两组之间PICP水平未发现差异。
研究结果表明，在固定可能不稳定的膝关节中，骨水泥/植入物界面处的骨转换可能更为活跃。这揭示了生化标志物在监测植入物固定和无菌性松动方面的潜在价值，并提示了通过抑制骨溶解的药物改善植入物固定的可能性。
