Ozalay Metin, Sahin Orcun, Akpinar Sercan, Ozkoc Gurkan, Cinar Murat, Cesur Necip
Department of Orthopaedics and Traumatology, Baskent University Hospital, Bahcelievler, Ankara, Turkey.
Arch Orthop Trauma Surg. 2009 Jun;129(6):747-52. doi: 10.1007/s00402-008-0781-9. Epub 2008 Nov 18.
Biphasic calcium phosphate (BCP) has proved to be an effective bone substitute, but it's effectiveness and remodeling potential in open wedge high tibial osteotomy (OWHTO) has not been analyzed yet. This study sought to evaluate the bone healing and remodeling potentials of BCP granules using a radiographic rating system in biplanar OWHTO.
Fifteen patients (15 knees) underwent biplanar OWHTO. Bone gaps were filled with BCP granules. For radiographic evaluation, remodeling was divided into four phases. Phase 1 was accepted as rounded osteotomy sites, with clear distinction between BCP and bone, phase 2 was accepted as whitened osteotomy sites, with distinction between BCP and bone still visible, phase 3 was accepted as distinction between BCP and bone not visible and cloudy bone formation and phase 4 was accepted as full reformation of BCP granules (4A-BCP visible, 4B-disappearence of BCP) with no sign of osteotomy. Bone union was confirmed with clinical (full weight bearing without pain) and radiographic evaluation (cortical bridging callus on radiographs and phase 3 or greater remodeling). The time to full remodeling and the starting point of the consolidation on anteroposterior radiographs were noted. Complications were also noted at each clinical follow-up.
Mean follow-up was 27.2 months. The mean age was 55.8 years. At clinical follow-up, there were no wound healing problems, no loss of corrections, no infections, and no complications. All osteotomies successfully healed. According to the radiologic classification system, at the 6th week, 73.3% (11/15) of patients were in phase 1 and the remaining 26.7% (4/15) were in phase 2. At 12-month follow-up, 46.7 (7/15) of the patients were still in phase 3. After 2 years, all radiographs showed to be in phase 4A. Radiographic union was noted to progress from lateral to medial and finally central.
BCP can be successfully used as a bone substitute. The radiographic remodeling and consolidation process of BCP was found to be different from that of beta-tricalcium phosphate. In our patients with more than 2 years of follow-up, BCP granules did not completely remodel. As a result, this clinical study demonstrated that calcium phosphate granules containing hydroxyapatite had a long period of "creeping substitution" that lasts longer than 2 years.
双相磷酸钙（BCP）已被证明是一种有效的骨替代物，但其在开放性楔形高位胫骨截骨术（OWHTO）中的有效性和重塑潜力尚未得到分析。本研究旨在使用双平面OWHTO的放射学评分系统评估BCP颗粒的骨愈合和重塑潜力。
15例患者（15个膝关节）接受双平面OWHTO。骨间隙用BCP颗粒填充。为进行放射学评估，将重塑分为四个阶段。第1阶段为圆形截骨部位，BCP与骨之间有明显区别；第2阶段为变白的截骨部位，仍可见BCP与骨之间的区别；第3阶段为BCP与骨之间的区别不可见且骨形成模糊；第4阶段为BCP颗粒完全重塑（4A - BCP可见，4B - BCP消失）且无截骨迹象。通过临床评估（完全负重且无疼痛）和放射学评估（X线片上皮质桥接骨痂以及3期或更高阶段的重塑）确认骨愈合。记录完全重塑的时间以及前后位X线片上骨痂形成的起始点。每次临床随访时也记录并发症情况。
平均随访时间为27.2个月。平均年龄为55.8岁。临床随访时，无伤口愈合问题、无矫正丢失、无感染及无并发症。所有截骨均成功愈合。根据放射学分类系统，在第6周时，73.3%（11/15）的患者处于第1阶段，其余26.7%（4/15）处于第2阶段。在12个月随访时，46.7%（7/15）的患者仍处于第3阶段。2年后，所有X线片显示处于4A阶段。放射学骨愈合从外侧向内侧并最终向中心进展。
BCP可成功用作骨替代物。发现BCP的放射学重塑和骨痂形成过程与β - 磷酸三钙不同。在我们随访超过2年的患者中，BCP颗粒未完全重塑。因此，这项临床研究表明含羟基磷灰石的磷酸钙颗粒有超过2年的长期“渐进性替代”。
