铁过载对绝经后骨质疏松患者骨密度和骨代谢的影响

目的 观察铁过载对绝经后骨质疏松患者骨密度和骨代谢的影响。方法 将234名绝经后妇女按照骨密度（bone mineral density, BMD）分为正常组、骨量减少组和骨质疏松组。分析铁过载对年龄、绝经年数、血钙(Ca)、磷(P)、体质量指数（bone mass index,BMI）、肝肾功能、葡萄糖代谢、脂质代谢、炎症反应、BMD、抗酒石酸酸性磷酸酶5b(TRACP-5b)、ALP、Ⅰ型胶原交联C端肽(β-CTX)和Ⅰ型胶原交联N端肽(PINP)的影响。结果 与正常组相比,骨量减少组和骨质疏松组血清铁蛋白(Fer)显著升高(P<0.05)。Fer水平与BMD呈负相关(P<0.05)。TRACP-5b水平在骨质疏松组明显高于正常组(P<0.05)。与正常组相比,骨质疏松症组的ALP水平显著升高(P<0.05)。与骨量减少组相比,骨质疏松组血清β-CTX水平明显升高(P<0.05);且骨质疏松组的PINP水平显著高于正常组(P<0.05)。更重要的是,血清Fer和PINP之间存在正相关(P<0.05);血清Fer和β-CTX之间呈正相关(P<0.05)。结论 铁过载对绝经后骨质疏松患者骨密度和骨代谢均有显著影响。     

骨代谢标志物在宁波地区绝经后女性骨质疏松症患者中的临床应用

目的 研究骨代谢标志物在宁波地区绝经后中老年女性骨质疏松症患者诊疗中的作用。方法 随机选择绝经后的中老年女性受试者264例,年龄均大于50岁,根据骨密度结果将264例检测对象根据骨密度大小分为骨量正常组82例,骨量减少组90例,骨质疏松组92例,同时采用电化学发光免疫分析方法测定受检对象血清中β-CTX、PINP、25-OHD3水平,并进行对比分析。结果 骨质疏松组：β-CTX水平与正常对照组、骨量减少组比较差异有统计学意义（P <0.05) ;PINP、25-OHD3水平在3组间差异无统计学意义（P>0.05)。结论骨质疏松症患者血清骨代谢标志物水平与骨质疏松存在密切的相关性;β- CTX是骨质疏松症诊断和疗效评估的理想指标;PINP、25-OHD3是骨质疏松症诊断和治疗的参考指标。     

绝经后2型糖尿病患者血清25(OH)D、Leptin与骨代谢的相关性

目的探讨绝经后2型糖尿病(type 2 diabetes mellitus,T2DM)女性患者血清25-羟维生素D(25-hydroxyvitamin D,25(OH)D)、瘦素(leptin,LEP)水平与骨代谢之间的关系。方法选取遵义医学院附属医院内分泌科住院的绝经后T2DM女性患者130例,根据骨密度分为骨量正常组(A组,n=40)、骨量减少组(B组,n=45)和骨质疏松组(C组,n=45),同期选取50名健康绝经后女性作为空白对照组(NC组,n=50)。收集所有受试者临床资料及生化指标,测定血清25(OH)D、LEP、β-胶原降解产物(β-Crosslaps,β-CTX)、I型胶原N-端前肽(N-aminoterminal propeptide of type I collagen,PINP)及骨钙素(bone gla protein,BGP)水平。Spearmen相关分析绝经后T2DM合并骨质疏松症(osteoporosis,OP)患者血清骨代谢指标的相关因素分析;Logistic回归分析绝经后T2DM患者合并OP的影响因素。结果①与NC组比较,A、B、C三组中25(OH)D、PINP、BGP水平均明显降低,而LEP、β-CTX水平明显升高(P0.05);②与A组比较,B组、C组中25(OH)D、PINP水平均明显降低,而LEP、β-CTX、BGP水平明显升高(P0.05);③与B组比较,C组中25(OH)D、PINP水平均明显降低,而LEP、β-CTX、BGP水平明显升高(P0.05);Spearmen相关分析显示,血清25(OH)D与PINP呈正相关,与β-CTX呈负相关,与BGP无明显相关性;血清LEP与PINP呈负相关,与β-CTX、BGP无关;Logistic回归分析显示BMI、HbA1c、25(OH)D、LEP、PINP与β-CTX均是绝经后T2DM患者合并骨质疏松的独立危险因素。结论血清25(OH)D水平的降低及LEP水平的升高,可能共同参与了绝经后T2DM女性患者OP的发生发展。     

绝经后髋部脆性骨折中铁过载指标与骨密度骨转换指标关系的研究

目的 研究绝经后髋部脆性骨折患者血清铁过载指标与骨代谢指标间的相互关系,对两者的临床表现进行探讨.方法 回顾性研究2011年2月至2012年6月76例绝经后髋部脆性骨折患者资料,年龄55 ～ 93岁,平均(73±10)岁;绝经时间5～50年,平均(22±10)年.患者均检测血清铁蛋白、转铁蛋白、碱性磷酸酶(ALP)、Ⅰ型原胶原氨基端延长肽(P1NP)、Ⅰ型胶原C端肽B降解产物(β-CTX)和双能X线股骨颈腰椎骨密度指标.采用t检验、Pearson线性相关分析、多元逐步回归分析、偏相关分析,观察铁代谢指标与骨代谢相关指标的关系.结果 患者血清铁蛋白值升至(230±146) μg/L,转铁蛋白降至(1.89±0.33)g/L.血清P1 NP升至(61±32) ng/L,ALP、β-CTX均在正常范围内.股骨颈和腰椎骨密度T值分别为-2.0±1.1和-2.1±1.2(正常范围-1.0～1.0).将患者按照其血清铁蛋白情况分为铁蛋白正常组(血清铁蛋白≤150 μg/L,25例)和铁蛋白升高组(血清铁蛋白＞ 150μg/L,51例).铁蛋白升高组较铁蛋白正常组的股骨颈和腰椎骨密度降低(t=3.13、2.89,P＜0.01),P1 NP和β-CTX升高(t=-2.38、-3.59,P＜0.05).校正混杂因素后,铁蛋白值与股骨颈和腰椎骨密度T值呈负相关(r=-0.335、-0.295,P＜0.05),与P1NP和β-CTX值呈正相关(r=0.467、0.414,P＜0.05),与ALP无显著相关性(r=0.188,P＞0.05);转铁蛋白值与股骨颈和腰椎骨密度T值呈正相关(r =0.444、0.262,P＜0.05),与ALP、P1NP、β-CTX值呈负相关(r=-0.326、-0.285、-0.278,P＜0.05).结论 绝经后髋部脆性骨折患者存在铁过载现象,铁过载与骨转换活跃导致骨量丢失相关,体内铁过载可能是一个独立影响绝经后骨代谢异常的因素.     

联合检测血清铁蛋白和胱抑素C对绝经后骨质疏松症的意义

目的分析探讨绝经后体检女性血清铁蛋白、胱抑素C与骨密度相关性。方法收集2015年10月至2019年4月南通市第一人民医院体检中心有完整临床资料的492例绝经后体检女性,年龄55～80岁。留取空腹静脉血检测血清铁蛋白(SF)、血清胱抑素(Cys-C)、血肌酐(Scr)、甲状旁腺素(PTH)、25-羟基维生素D(25OHD)、骨钙素(OC)、Ⅰ型原胶原氨基端延长肽(PⅠNP)和Ⅰ型胶原C端肽β降解产物(β-CTX)等指标,双能X线骨密度仪检测左髋股骨颈、总股骨和腰椎1-4骨密度,分析血清铁蛋白和胱抑素C与骨密度相关性及骨质疏松症发生相对风险。结果本组人群骨质疏松发生率46.5%,不同骨密度组年龄、体重、BMI、SF、Cys-C、25OHD、PⅠNP和β-CTX组间差异有统计学意义;血清铁蛋白和胱抑素的四分位数分组中,年龄、体重、BMI、Scr及各部位骨密度T值组间差异有统计学意义;控制年龄、体重、BMI、Scr、25OHD和PⅠNP等指标后,高血清铁蛋白和胱抑素C组骨质疏松相对风险分别为2.272(95%CI:1.090～4.727)和2.224(95%CI:1.047-4.723)。结论血清铁蛋白和胱抑素C升高是绝经后骨质疏松症发生的独立危险因素,需要重视绝经后女性血清铁蛋白和胱抑素C的变化。     

OPG-RANKL-RANK系统对绝经后女性类风湿关节炎患者骨代谢的影响

目的探讨绝经女性类风湿关节炎(RA)患者外周血核因子-κB受体活化因子配体(RANKL)、骨保护素(OPG)与炎症因子及骨代谢指标之间的相关性。方法收集绝经女性RA患者45例和健康对照组25例。采用双能X射线骨密度测量仪(DEXA)测骨密度,酶联免疫吸附法(ELISA)测定人外周血清RANKL、OPG、IL-6水平,并详细记录临床、实验室资料。两组间计量资料比较采用t检验,相关分析采用Pearson积差相关法。结果 1与健康对照组相比,绝经女性RA组的骨密度、OPG/RANKL低于对照组,RANKL、IL-6水平高于对照组(P0.05),OPG在两组间并无统计学差异(P0.05)。2绝经女性RA患者OP组较非OP组有更高的抗CCP抗体水平(P0.05),RANKL、OPG、DAS28评分等并无差异(P0.05)。3绝经女性RA患者外周血中RANKL与DAS28评分、PINP、β-CTX、IL-6正相关(r=0.357,0.381,0.370,0.330,P0.05),OPG与PINP、β-CTX、IL-6正相关(r=0.561,0.511,0.328,P0.05)。结论绝经女性RA患者RANKL水平与炎症因子IL-6的诱导密切相关,但作为动态变化指标,仅反映近期骨代谢状况,并不能反映长期骨密度的变化。     

绝经后女性2型糖尿病伴骨质疏松患者骨密度与骨代谢指标的相关性分析

目的分析研究绝经后女性2型糖尿病伴骨质疏松症患者骨密度与骨代谢指标的相关性。方法选取2013年10月至2017年05月于重庆医科大学附属第一医院内分泌内科住院的绝经后女性2型糖尿病患者385名。搜集其基本资料、骨代谢指标及骨密度等。根据T值将这些患者分为骨质疏松组(233例)、骨量减少组(101例)和骨量正常组(51例),比较三组间骨代谢指标的变化,并对骨密度(bone mineral density,BMD)与各项骨代谢指标进行相关性分析。结果 1型前胶原氨基末端前肽(Type I procollagen N-terminal propeptide,P1NP)、骨钙素(bone Gla protein,BGP)在骨质疏松组显著高于骨量减少组、骨量正常组(P0.05);随着骨密度的降低,1型胶原羧基端肽β特殊序列(β-Carboxyl terminal peptide,β-CTX)逐渐升高,骨质疏松组、骨量减少组与骨量正常组相比较差异有统计学意义(P0.05);Spearman等级相关分析示P1NP、BGP、β-CTX与骨密度呈负相关,25(OH)D_3与骨密度呈现正相关。结论绝经后女性2型糖尿病伴骨质疏松症患者骨密度与骨代谢指标有一定的相关性,有助于预测骨折风险并及时抗骨质疏松治疗。     

白藜芦醇对绝经后骨质疏松女性骨代谢和氧化代谢产物水平的影响

目的 探讨白藜芦醇对绝经后骨质疏松症妇女骨代谢和氧化代谢产物水平的影响。方法 选取 2015年11月至 2017年11月在成都市第二人民医院就诊的84例绝经后骨质疏松症患者作为研究对象,随机分为治疗组和对照组。治疗组的患者每天服用白藜芦醇,对照组的患者给予安慰剂片。3个月后,测量各组患者的血清骨代谢标志物[I型前胶原氨基端前肽(PINP)、骨钙素(BGP)、骨碱性磷酸酶(BALP)、I 型胶原 C 末端肽特殊序列(β-CTX)]和氧化代谢产物[蛋白羰基(PCO)、高级氧化蛋白产物(AOPP)、总抗氧化能力(TAC)、Akatsu(MDA)]水平的改变。结果 服用白藜芦醇治疗后,治疗组血清PINP 、BGP 、BALP 、β-CTX 、PCO、AOPP和MDA水平较治疗前显著降低(P＜0.05),治疗后两组之间的差异具有统计学意义(P＜0.05);治疗组血清TAC水平较治疗前显著升高(P＜0.05),治疗后两组之间的差异具有统计学意义(P＜0.05)。然而,对照组治疗前后的PINP 、BGP 、BALP 、β-CTX 、PCO、TAC、AOPP和MDA指标,其差异并没有统计学意义(P＞0.05)。结论 白藜芦醇可以降低绝经后骨质疏松症女性体内氧化应激和高骨转化速度。     

骨代谢标志物变化情况与绝经后女性发生骨质疏松性椎体压缩骨折的相关性分析

目的探讨骨代谢标志物与绝经后女性发生骨质疏松性椎体压缩骨折(osteoporotic vertebral compression fractures,OVCF)的相关性。方法纳入2016年7月~2017年5月收治的OVCF患者60例,作为研究组;另纳入原发性骨质疏松症、但未发生OVCF的绝经后女性患者60例,作为对照组。检测两组患者的骨密度值、β-Ⅰ型胶原羧基端肽(β-C-terminal telopeptide of type I collagen,β-CTX)、I型原胶原氨基端延长肽(propeptide of type I procollagen,PINP)、骨钙素N端中分子片段(N-MID osteocalcin,N-MID),以及25-羟维生素D[25-hydroxy vitamin,25-(OH)VitD]的血清浓度,并测定钙离子(Ca2+)浓度。对两组患者的上述指标进行分组对比,并对骨代谢标志物与OVCF的相关性进行二分类Logistic回归分析。结果①研究组的髋部、腰椎骨密度值均低于对照组,但组间无显著性差异(P0.05);研究组的β-CTX、PINP水平显著高于对照组,25-(OH)VitD水平显著低于对照组,差异均有统计学意义(P0.05);而N-MID、Ca2+两项指标水平在组间差异无统计学意义(P0.05)。②相关性分析显示:血清PINP、β-CTX水平与OVCF之间呈显著的正相关关系(P0.05),25-(OH)VitD与之呈显著的负相关关系(P0.05)。结论绝经后女性的血清PINP、β-CTX水平越高,25-(OH)VitD水平越低,则发生OVCF的风险越高;针对上述指标异常表达者,应予以积极干预,以降低OVCF的发生风险。     

绝经后女性骨密度与骨代谢生化指标的相关性分析

目的分析绝经后女性骨密度(bone mineral density,BMD)与骨代谢生化指标的相关性。方法选取西南医科大学附属医院2017年1月至2018年12月收治的绝经后女性患者151例。根据骨密度T值将患者分为骨质疏松组(83例)、骨量低下组(47例)和骨量正常组(21例),比较三组患者骨代谢生化指标的差异,并对各项指标与BMD进行相关性分析。结果骨质疏松组甲状旁腺素(PTH)、Ⅰ型前胶原氨基末端前肽(P1NP)、Ⅰ型胶原羧基端肽β特殊序列(β-CTX)显著高于骨量低下组和骨量正常组(P0. 05),骨量低下组显著高于骨量正常组(P0. 05)。骨质疏松组体质量指数(bone mass index,BMI)、25(OH) D_3显著低于骨量低下组和骨量正常组(P0. 05),骨量低下组显著低于骨量正常组(P0. 05)。血钙、血磷、骨钙素(BGP)、血清的骨特异性碱性磷酸酶(BALP)在三组之间比较,差异无明显统计学意义(P0. 05)。Spearman相关分析显示,PTH、P1NP、β-CTX与骨密度呈负相关(r=-0. 538,-0. 520,-0. 462,P 0. 05),25(OH) D_3与骨密度呈正相关(r=0. 517,P0. 05),血钙、血磷、BALP、BGP与骨密度无相关性(P0. 05)。结论血清25(OH) D_3、PTH、P1NP、β-CTX与骨密度存在显著相关性,骨代谢生化指标监测有助于绝经后女性骨质疏松的早期诊断。     

感染性骨缺损的治疗及研究进展

感染性骨缺损由于存在感染及骨缺损双重病变,治疗棘手,疗程长,且易出现肌肉萎缩、局部瘢痕而致肢体功能受到严重影响.近年来随着外固定技术、显微外科技术、生物材料技术及骨组织工程技术等的发展,感染性骨缺损的治疗取得明显进步,短缩了治疗时间,且效果显著,笔者对其研究进展综述如下.     

Building better bone: The weaving of biologic and engineering strategies for managing bone loss

Segmental bone loss remains a challenging clinical problem for orthopaedic trauma surgeons. In addition to the missing bone itself, the local tissues (soft tissue, vascular) are often highly traumatized as well, resulting in a less than ideal environment for bone regeneration. As a result, attempts at limb salvage become a highly expensive endeavor, often requiring multiple operations and necessitating the use of every available strategy (autograft, allograft, bone graft substitution, Masquelet, bone transport, etc.) to achieve bony union. A cost‐sensitive, functionally appropriate, and volumetrically adequate engineered substitute would be practice‐changing for orthopaedic trauma surgeons and these patients with difficult clinical problems. In tissue engineering and bone regeneration fields, numerous research efforts continue to make progress toward new therapeutic interventions for segmental bone loss, including novel biomaterial development as well as cell‐based strategies. Despite an ever‐evolving literature base of these new therapeutic and engineered options, there remains a disconnect with the clinical practice, with very few translating into clinical use. A symposium entitled “Building better bone: The weaving of biologic and engineering strategies for managing bone loss,” was presented at the 2016 Orthopaedic Research Society Conference to further explore this engineering‐clinical disconnect, by surveying basic, translational, and clinical researchers along with orthopaedic surgeons and proposing ideas for pushing the bar forward in the field of segmental bone loss. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1855–1864, 2017.

     

Osteogenesis after Bone and Bone Marrow Transplantation: II. The Initial Cellular Events Following Transplantation of Decalcified Allografis of Cancellous Bone

An experimental study was done in rabbits to investigate the fate of allogeneic iliac cancellous bone, both non-decalcified and decalcified with hydrochloric acid, transplanted to a muscular site for up to 14 days. Some of the treated allografts were impregnated with autologous bone marrow cells, obtained from the femoral medulla by aspiration, and each was compared with allografts alone. Combined myelo-osseous grafts produced bone after 7 to 8 days implantation, as did marrow autografts alone. In addition non-decalcified implants stimulated the production of multinucleated giant cells. Three different types of wash solution were used but these did not influence the cell population seen, nor the new bone formation. It is concluded that the critical events in bone formation after transplantation occur less than 8 days after the transplantation and that marrow cells have osteogenic capacity. This has relevance to the clinical aspects of bone grafting.     

骨肿瘤病段切除并骨缺损修复

目的 修复切除骨肿瘤后的骨缺损肢体,恢复其功能。方法 采用特制人工金属假体,带血管蒂游离骨、异体关节、自体骨、骨水泥等修复骨缺损。结果 26例中应用带血管蒂游离骨或自体骨植骨术愈合最佳并且无复发;异体骨移植有一定的排异反应;骨水泥堵塞只适用于特殊部位骨缺损的修复;人工假体修复,功能恢复良好。结论 对某些良性骨肿瘤及低度恶性的骨肿瘤作病段切除后,选择适当的替代物修复缺损行之有效。     

Bone cement with reduced proportion of monomer in total hip arthroplasty: Preclinical evaluation and randomized study of 47 cases with 5 years' follow-up

Bone cement with reduced amount of monomer and low curing temperature may improve implant fixation due to reduced toxicity. We analyzed the mechanical, chemical and thermal properties of such a cement (Cemex Rx) using Palacos R as control. The in vivo performance of the 2 cements was also evaluated in a prospective randomized study of 47 hips, where either of the cement types was used to fixate Lubinus SP2 prostheses with the stem made of titanium alloy. Cemex Rx had a reduced tensile strength, probably because this cement was manually mixed, as recommended by the manufacturer. A standardized laboratory test showed lower curing temperature for Cemex, but measurements at 37° and with prechilled Palacos R and Cemex Rx, as in clinical work, showed no difference. In the clinical study radiostereometric measurements of cup and stem migration showed similar values in the 2 groups up to 5 years after the operation. The cement mantle was stable in both groups, but the stems migrated similarly inside the cement mantle regardless of the type of cement used. Proximal wear was low (0.04-0.05 mm/year) and tended to be lower in the Cemex group (p = 0.02). Aluminum and vanadium levels in serum increased 5 years after the operation, but no difference was noted between the 2 groups. Collagen markers (PICP, ICTP) showed similar increases in bone turnover 6 weeks and 6 months after operation in both groups.     

Bone Remodeling and in Vivo Strain Analysis of Intact and Implanted Greyhound Proximal Femora

Pre- and poststudy motion and gait analyses of eight size-matched male greyhounds confirmed uniform loading of their femora. Subminiature strain gages implanted on the intact inferior and anterior aspects of the femoral neck in six greyhounds indicated in vivo strain variations among test animals. Motion and gait analyses confirmed uniform loading of femora following unilateral hemiarthroplasty with cobalt-chromium hip implants. In vivo strain measurements adjacent to the implants indicated large variations among test animals. A consistent direction of strain change relative to the intact femur was noted, even though strain changes varied in magnitude. Image analysis of microradiographs indicated insignificant differences in the cortical areas of implanted and intact femora. Extensive new trabecular bone formation was noted along the implant in the endosteal cavity and correlated with a combination of implant placement and exercise level. Most of the bone was formed with centrally placed implants in exercised dogs, and the least with stems on the medial neck surface in rested dogs. Iliac crest biopsies indicated that bone formation rates slowed in rested animals and remained constant throughout the study in exercised animals. All implanted femora had a thin (<1 mm thick) aligned fibrous tissue layer separating the implant from bone. It varied in thickness as a function of the aspect of the implant. Exercised dogs had a larger proportion of fibrous tissue on the anterior and posterior aspects, while rested dogs had a larger proportion of fibrous tissue on the medial and lateral aspects.     

Viability and Osteogenicity of Bone Graft Coated with Methylmethacrylate Cement

The idea of utilizing bone grafts during hip arthroplasty has been discussed in the literature and clinical successes have been indicated. These communications, however, did not relate to long-term results. Thus, to date, we still lack sufficient understanding as to the fate of bone grafts when they are coated with methyl-methacrylate. In order to elucidate the above issue further an experimental study has recently been initiated in an attempt to provide answers to the following questions: a) do bone grafts remain viable when they are held in place with methyl-methacrylate bone cement? and b) do such grafts retain their osteogenic potential? In the present study osteotomies were made in the femora of dogs and cortico-cancellous strips of autogenous bone were placed around the osteotomy site. The grafts were then surrounded by polymethylmethacrylate bone cement. Mechanical examinations and morphological studies, performed 3, 6 and 10 months following surgery, revealed the elaboration of fibro-osseous union. Our present findings tend to indicate that bone grafts, even if they are covered with methylmethacrylate bone cement, still retain their viability as well as their osteogenic potential.     

The Penetration of Lincomycin into Normal Human Bone: Determinations of Penetration into Compact Bone, Spongy Bone and Bone Marrow

The penetration of lincomycin into normal bone was studied in 10 patients with fracture of the neck of the femur, a separate determination being made of the lincomycin concentration in serum, bone marrow, spongy bone and compact bone. The concentration of lincomycin in bone marrow was found to be at the same level as that in the serum. The concentration in spongy bone amounted in most cases to 50 to 75 per cent of the concentration in the serum, whereas the concentration in compact bone varied from 0 to 15 per cent of that in the serum.     

Bone Marrow Cell Content and Osteoclasts in Crista Biopsies

The bone marrow cell content was investigated by counting the percentage of cells in the areas between the trabeculae in crista biopsies. There was a decrease in the percentage of cells in bone marrow in osteoporotic women compared with our normal material. in patients undergoing haemodialysis there was a positive correlation between bone marrow cell content and osteoclasts, which could indicate a possible connection between osteoclasts and bone marrow cells.     

Torsional Strength of Cortical and Cancellous Bone Grafts After Rigid Plate Fixation

Mechanical properties of cortical and cancellous interposition grafts in rabbit tibio-fibular bones fixed with 6-hole DCP/ASIF plates were tested with torsional loading after intervals of 3 to 52 weeks postoperatively.

In the cortical grafts maximum torque moment at fracture, energy absorption capacity and rigidity increased from 3 to 12 weeks, while the cancellous grafts were more plastic with lower rigidity, higher angular deformation and higher energy absorption.

From 12 to 52 weeks maximum torque moment at fracture, energy absorption, rigidity and angular deformation decreased in grafts of both types, the respective means at 36 weeks being 39, 34, 57 and 82 per cent of the control values for the cortical grafts, and 26, 17, 42 and 58 per cent of the control values for the cancellous grafts. The differences between the torsional properties of the two graft types decreased with time.