补肾除湿联合富血小板血浆调控血清TGF-β1及Smad-1水平治疗膝骨关节炎

目的：探讨补肾除湿联合富血小板血浆（platelet-rich plasma，PRP）治疗早中期膝骨关节炎（knee osteoarthritis，KOA）的临床疗效及对患者血清中转化生长因子-β1（transforming growth factor-β1，TGF-β1）和Smad-1水平的影响。方法：选取2020年5月至2022年4月收治的45例早中期KOA患者，分为对照组和观察组。对照组30例，男12例，女18例；年龄43~69（57.3±6.5）岁；Kellgren-Lawrence （K-L）分级Ⅰ级8例，Ⅱ级13例，Ⅲ级9例；病程1.5~5.0（3.8±1.7）年；分别于1、3周时向患膝关节腔注射5 ml的PRP 1次，共2次。观察组15例，男7例，女8例；年龄45~70（56.7±6.2）岁；K-L分级Ⅰ级4例，Ⅱ级9例，Ⅲ级2例；病程1.8~5.7（4.0±1.8）年；注射PRP 5 ml，时间、次数与对照组相同，同时口服补肾除湿方水煎剂，每日1剂，共28剂。两组疗程均为4周。分别于治疗前后采用疼痛视觉模拟评分（visual analogue scale，VAS）和Lequesne MG评分评估患膝疼痛及关节功能改善情况。分别于治疗前、治疗结束后1 d采用酶联免疫吸附试验（enzyme linked immunosorbent assay，ELISA）检测TGF-β1、Smad-1的含量，并观察两组患者并发症发生情况。结果：45例患者获得随访，时间26~30（28.0±0.6） d。治疗前两组VAS和膝关节Lequesne MG评分比较，差异无统计学意义（P>0.05）；治疗结束后1 d，两组VAS和膝关节Lequesne MG评分均低于治疗前（P<0.05）；治疗结束后1 d，观察组VAS和膝关节Lequesne MG评分低于对照组（P<0.05）。两组治疗结束后1 d，TGF-β1含量均较治疗前降低（P<0.05）；治疗结束后1 d，观察组TGF-β1含量低于对照组（P<0.05）。两组治疗结束后1 d的Smad-1含量与治疗前比较，差异无统计学意义（P>0.05）；治疗结束后1 d，观察组Smad-1含量高于对照组（P<0.05）。两组并发症情况比较，差异无统计学意义（P>0.05）。结论：补肾除湿联合关节腔注射PRP治疗早中期KOA疗效确切，优于单纯关节腔内注射PRP，并在一定程度上降低患者血清TGF-β1水平，升高Smad-1水平，抑制炎症反应，促进软骨修复，这可能是补肾除湿联合PRP治疗KOA的作用机制之一。     

膝关节骨关节炎相关炎症及软骨代谢标志物的表达与临床意义

目的检测COMP、MMP-13、Cbf-β在膝关节骨关节炎(knee osteoarthritis,KOA)患者血清、尿液、关节液及关节软骨内的表达,探讨其对KOA早期诊断、病情评估的临床意义。方法应用ELISA法检测KOA患者及健康志愿者血液、尿液、关节液中COMP、MMP-13、Cbf-β的表达情况,应用Western blot检测KOA及对照组膝关节软骨组织COMP、MMP-13、Cbf-β的表达情况。结果 KOA患者血清、关节液中COMP、MMP-13、Cbf-β的表达高于健康志愿者,在健康对照组、试验对照组、试验组间的表达逐渐增高,组间差异有统计学意义(P0.05),KOA患者尿液中COMP、MMP-13的表达高于健康志愿者,在健康对照组、试验对照组、试验组间的表达逐渐增高,组间差异有统计学意义(P0.05),KOA患者膝关节软骨COMP、MMP-13、Cbf-β的表达高于对照组,差异有统计学意义(P0.05)。结论 COMP、MMP-13、Cbf-β在血清、尿液、关节液及关节软骨内的高表达可能预示KOA的发生,为KOA的早期诊断提供参考依据。COMP、MMP-13、Cbf-β在病变较重患者的表达高于病变较轻者,表达含量越高,可能WOMAC评分与K-L分级越高,为KOA的病情评估提供参考依据。     

体外冲击波联合康复治疗对早中期膝骨关节炎病人Coll2-1、COMP水平的影响

目的 探讨体外冲击波联合康复治疗对早中期膝骨关节炎（knee osteoarthritis, KOA）病人的治疗效果及其对关节液中胶原蛋白2-1（Collagen2-1, Coll2-1）、软骨寡聚基质蛋白（COMP）水平的影响。方法 选取2014年6月至2016年12月间收治的72例膝骨关节炎病人,随机分为对照组（36例）和观察组（36例）,对照组病人给予关节腔内注射玻璃酸钠治疗,观察组给予体外冲击波治疗,且两组均给予康复理疗措施。分别在治疗前及治疗后2个月时,采用活动时疼痛视觉模拟量表（visual analogue scale, VAS）评分、骨关节炎病人疼痛指数（Lequesne index）和美国西部安大略和麦克马斯特大学（the Western Ontario and McMaster Universities, WOMAC）骨关节炎指数评价两组的疗效,采用酶联免疫吸附试验（ELISA）测定关节液中Coll2-1、COMP的含量。结果 两组病人治疗后的VAS评分、Lequesne指数、WOMAC评分均明显降低（P均＜0.05）,治疗后观察组各项评分明显低于对照组（P均＜0.05）。治疗后两组病人关节液中Coll2-1、COMP的水平均比治疗前显著下降（P均＜0.05）,观察组下降程度明显优于对照组（P均＜0.05）。结论 体外冲击波联合康复治疗对膝骨关节炎病人的疗效较好,可明显减轻关节疼痛,改善膝关节活动功能,且明显降低病人关节液中的Coll2-1、COMP水平。     

滑液中PRTN3和MNDA诊断关节假体周围感染的效能：与α-防御素的比较

目的 检测关节滑液中标志物蛋白酶3（proteinase 3,PRTN3）和髓样细胞核分化抗原（myeloid nuclear differentiation antigen,MNDA）在关节假体周围感染（periprosthetic joint infection,PJI）诊断中的临床效能,并与传统标志物α-defensin进行比较。方法 回顾性收集连续65例因怀疑PJI而进行髋膝关节诊断性穿刺病人的关节滑液标本。基于2014年肌肉骨骼感染协会（Musculoskeletal Infection Society,MSIS）标准,将29例纳入PJI组,36例纳入非PJI组。随后使用商用ELISA试剂盒检测关节滑液中的三种标志物水平。采用受试者工作特征（receiver operating characteristic,ROC）曲线分析评价所研究生物标志物的诊断效能,并计算其各自的敏感度、特异度与截断值。结果 PJI组菌培养结果以葡萄球菌为主,占比31%,培养阴性病人占比34.5%。ROC分析结果显示,PRTN3的曲线下面积（area under the curve,AUC）最大,为0.984（95% CI,0.961~1.000),其次是α-defensin,AUC为0.944（95% CI,0.888~1.000）,最后为MNDA,AUC为0.849（95% CI,0.755~0.943）。PRTN3的最佳截断值为318.000（ng/mL）,敏感度为0.931,特异度为0.972。α-defensin的最佳截断值为7.150（μg/mL）,敏感度为0.931,特异度为0.861。MNDA的最佳截断值为4.318（ng/mL）,敏感度为0.862,特异度为0.722。结论 PRTN3和MNDA都是PJI的优秀生物标志物。PRTN3的诊断性能最好,甚至略优于α-defensin。     

重度膝骨关节炎与骨髓水肿相关性研究

目的：探讨骨髓水肿与重度膝骨关节炎病理改变及症状体征的关系。方法：自2020年1月至2021年3月于中国中医科学院望京医院骨关节科就诊已行膝关节MRI检查的重度膝骨关节炎患者160例。合并骨髓水肿患者80例为病例组,男12例,女68例,年龄51~80（66.58±8.10）岁,病程5~40（15.61±9.25）个月,身体质量指数（body mass index,BMI）21.81~34.70（27.79±3.00） kg·m^-2;不合并骨髓水肿的患者80例为对照组,男15例,女65例,年龄50~80（67.82±8.05）岁,病程6~37（15.75±8.18）个月,BMI 21.39~34.46（28.26±3.13） kg·m^-2。采用膝关节整体磁共振成像评分（whole oragan magnetic resonance imaging score,WORMS）评价骨髓水肿程度,采用Kellgren-Lawrence （K-L）等级、Western Outario and McMaster大学骨关节炎指数评分（Western Ontario and McMaster University osteoarthritis index,WOMAC）评价膝骨关节炎病变程度,采用视觉模拟评分（visual analogue scale,VAS）,WOMAC疼痛评分评价关节疼痛程度,采用压痛、叩击痛、关节肿胀度、关节活动度评分评价关节体征。比较两组患者K-L等级分布的差异探讨骨髓水肿与膝骨关节炎病变程度的关系;并进一步通过Spearman相关性分析病例组患者骨髓水肿WORMS评分与WOMAC指数、疼痛相关评分、体征相关评分的相关系数,以进一步探讨骨髓水肿与膝骨关节炎指数、关节疼痛症状、体征的关系。结果：病例组患者K-L等级Ⅳ级者占68.75%（55/80）,对照组患者等级Ⅳ级者占52.50%（42/80）,病例组中Ⅳ级患者所占比例高于对照组（χ²=4.425,P<0.05）。病例组患者骨髓水肿WORMS与膝骨关节炎WOMAC指数相关系数为强正相关（r=0.873>0.8,P<0.001）,骨髓水肿WORMS与VAS相关系数r=0.752>0.5,与WOMAC量表疼痛评分相关系数r=0.650>0.5,为中度相关（P<0.001）;骨髓水肿WORMS与叩击痛评分相关系数r=0.784>0.5,（P<0.001）,为中度相关（P<0.05）;骨髓水肿WORMS评分与压痛评分相关系数r=0.194<0.3、关节肿胀度评分相关系数r=0.259<0.3、关节活动度评分相关系数r=0.296<0.3,相关性极弱（P<0.05）。结论：膝骨关节炎病变越严重越容易引起骨髓水肿,同时骨髓水肿亦可加重膝骨关节炎病情;骨髓水肿可导致膝骨关节炎关节疼痛,叩击痛阳性体征,而压痛、关节肿胀、活动受限与骨髓水肿无明显相关。     

血清神经突起因子和转化生长因子-β1对脊柱骨折合并脊髓损伤患者神经功能恢复的预测作用

目的 探讨入院时血清神经突起因子、转化生长因子-β1（TGF-β1）水平对脊柱骨折合并脊髓损伤患者术后神经功能恢复情况的预测价值。方法 纳入2018年2月—2019年3月收治的84例单节段脊柱骨折合并脊髓损伤患者为研究对象。采用美国脊髓损伤协会（ASIA）分级评估患者神经功能恢复情况，将术后末次随访时ASIA分级较治疗前提高者归入恢复良好组（n=50），无变化或降低者归入恢复较差组（n=34），比较2组患者入院时基线资料与实验室指标水平，采用logistic回归方法和受试者工作特征（ROC）曲线分析入院时血清神经突起因子、TGF-β1水平与神经功能恢复情况的关系。结果 2组性别、年龄、体质量指数（BMI）、骨折节段、脊髓损伤节段、受伤原因、骨折AO分型、脊髓损伤时间、Ogawa创伤指数等基线资料差异无统计学意义（P > 0.05）。恢复较差组患者术前血清神经突起因子水平、TGF-β1水平低于恢复良好组，差异均有统计学意义（P < 0.05）。Logistic回归分析结果显示，入院时血清神经突起因子、TGF-β1水平低可能是脊柱骨折合并脊髓损伤患者术后神经功能恢复较差的危险因素（比值比=1.253，95%置信区间为1.130 ~ 1.389，P < 0.05；比值比=1.167，95%置信区间为1.088 ~ 1.252，P < 0.05）；绘制ROC曲线发现，入院时血清神经突起因子、TGF-β1水平单独及联合预测脊柱骨折合并脊髓损伤患者术后神经功能恢复的曲线下面积分别为0.844、0.809、0.908，两者联合应用时预测效果最佳。结论 脊柱骨折合并脊髓损伤患者入院时血清神经突起因子、TGF-β1水平与术后神经功能恢复情况有关，入院时血清神经突起因子、TGF-β1水平低可能预示患者术后神经功能恢复较差。     

弥散张量成像联合血清白细胞介素-1β、磷酸化高分子量神经微丝蛋白诊断脊髓损伤

目的 观察弥散张量成像(DTI)联合血清白细胞介素-1β(IL-1β)、磷酸化高分子量神经微丝蛋白(pNF-H)诊断脊髓损伤的价值。方法 回顾性分析69例脊髓损伤(C1~T1水平损伤)患者(观察组)和100名健康体检者(对照组) DTI资料,记录其表观弥散系数(ADC)、各向异性分数(FA)值,以及血清IL-1β、pNF-H水平。根据美国脊髓损伤协会(ASIA)残损分级法对观察组脊髓损伤程度进行分级(D/C/B/A级);比较组间及观察组内不同脊髓损伤分级患者DTI参数及血清指标的差异,分析DTI参数及血清指标与脊髓损伤严重程度的相关性。以受试者工作特征(ROC)曲线及曲线下面积(AUC)评估ADC、FA、IL-1β、pNF-H值单独及联合诊断脊髓损伤的效能。结果 相比对照组,观察组FA值降低,ADC值及血清IL-1β、pNF-H水平升高(P均=0.001)。随ASIA分级由D级至A级,观察组FA值逐渐降低,ADC值及血清IL-1β、pNF-H水平逐渐升高(P均<0.05);脊髓损伤严重程度与FA值呈负相关(r=-0.489,P<0.001),与ADC值及血清IL-1β、pNF-H水平呈正相关(r=0.542、0.599、0.596,P均<0.001)。FA值、ADC值及血清IL-1β、pNF-H单独诊断脊髓损伤的AUC分别为0.747、0.809、0.794、0.741,联合诊断为0.845(P均=0.01)。结论 DTI联合血清IL-1β、pNF-H有助于诊断脊髓损伤。     

未成熟粒细胞计数预测脊柱手术术后早期感染的应用价值

目的：评估未成熟粒细胞在脊柱手术术后感染的早期预测价值。方法：收集2016年10月至2018年10月期间收治的78例脊柱手术患者的临床资料,其中男57例,女21例;年龄45～63（55.2±6.1）岁,最常见的损伤病因是脊柱外伤或退行性变。按美国脊髓损伤协会（ASIA）脊髓损伤分级,完全损伤为37例（A级和B级）,不完全损伤为41例（C级和D级）。78例患者均表现为不同程度的肢体深浅感觉障碍,均在入院后完善相应椎体节段的CT及MRI检查,根据患者术后1周内是否发生继发性感染分为感染组和未感染组。测量入院时及术后1、3、6 d的IG#（未成熟粒细胞绝对值）,IG%（未成熟粒细胞百分比）,CRP,PCT,IL-1β,IL-6,TNF-α等指标,运用ROC曲线比较IG%、IG#、PCT在早期判断术后感染的预测价值,使用Spearman相关性检验分析IG%、IG#与PCT的相关性。结果：术后1周33例发生感染,45例未发生感染。出院时未发生严重并发症及死亡病例,感染组完全性损伤的比例显著高于未感染组（P=0.046）,并且感染组损伤部位多为颈胸椎,未感染组多为腰椎损伤（P=0.044）。术后1 d,PCT、IG%、IG#感染组分别为（0.71±0.10）ng/ml、1.08±0.10、0.20±0.05,末未感染组为（0.51±0.08）ng/ml、0.82±0.13、0.13±0.04,两组差异有统计学意义（P<0.001）;术后3 d,CRP、PCT、IL-6、IL-1β、TNF-α、IG#、IG%感染组为（80.47±15.74）mg/L、（2.39±0.27）ng/ml、（15.74±3.85）pg/ml、（16.47±4.75）pg/ml、（2.18±0.57）ng/ml、0.28±0.10、1.38±0.54,非感染组为（62.42±14.68）mg/L、（0.89±0.21）ng/ml、（13.10±3.87）pg/ml、（14.57±3.35）pg/ml、（1.63±0.37）ng/ml、0.09±0.01、0.83±0.24,两组差异有统计学意义（P<0.001）。术后6 d,感染组的各实验室指标均显著高于未感染组（P<0.001）。ROC曲线分析结果显示,PCT、IG%、IG#均可以预测SCI术后早期感染（P<0.001）,IG#的曲线下面积（AUC）显著低于PCT和IG%,分别为0.847、0.947、0.934（P<0.05）。相关性分析结果显示,IG%、IG#与PCT均呈显著相关,相关系数分别为0.724和0.472（P<0.001）。结论：脊髓损伤患者术后24 h内升高的IG%、IG#、PCT水平对预测早期继发感染具有较高的敏感度与特异度,术后量化这些指标有助于早期识别具有感染高风险的患者。     

个体化股骨远端外旋截骨全膝关节置换术对膝关节骨性关节炎病人关节功能及康复效果的影响

目的 探究个体化股骨远端外旋截骨全膝关节置换术（TKA）对膝关节骨性关节炎（KOA）病人膝关节功能及康复效果的影响。方法 选取2021年3月至2022年3月我院医治的98例KOA病人,依据随机数字表法分为两组,各49例。对照组采用常规TKA治疗,研究组采用个体化股骨远端外旋截骨TKA治疗。比较两组围术期情况,手术前后纽约特种外科医院膝关节评分（HSS）、美国膝关节学会评分（KSS）、关节活动度,以及关节液基质金属蛋白酶-9（MMP-9）、可溶性细胞间黏附分子-1（sICAM-1）、关节液肿瘤坏死因子-α（TNF-α）等康复效果相关指标,冠状位股骨远端机械轴外侧角（mLDFA）、下肢机械轴夹角（HKA）等力线参数,支撑时间百分比、步幅、步速等步态参数,疼痛视觉模拟量表（VAS）评分,关节炎生活质量测量量表2（AIMS2）评分,术后并发症。结果 两组随访时间均在6个月以上,无失访病例。研究组住院时间明显短于对照组［（6.24±1.18） d vs. （7.36±1.05） d］,差异有统计学意义（P＜0.05）。术后研究组并发症发生率（6.12%）与对照组（10.20%）相比,差异无统计学意义（P＞0.05）。两组术后各项指标均较术前改善,且研究组术后第3、6个月HSS评分、KSS稳定性评分、活动度均高于对照组,冠状位mLDFA、HKA均低于对照组,支撑时间百分比、步速、步幅均高于对照组,VAS评分、AIMS2评分低于对照组,组间比较,差异均有统计学意义（P＜0.05）。术后第3个月,研究组和对照组关节液TNF-α、sICAM-1、MMP-9水平均低于术前（P＜0.05）,但组间比较,差异无统计学意义（P＞0.05）。结论 与常规TKA治疗相比,个体化股骨远端外旋截骨TKA治疗能降低关节液TNF-α、sICAM-1、MMP-9水平,改善关节力线参数,提高膝关节功能,调整步态参数,降低术后疼痛程度,提高病人术后生活质量。     

急性超容血液稀释对老年脊柱手术患者S-100β蛋白、NSE水平及POCD的影响

目的：探讨急性超容血液稀释（AHH）对老年脊柱手术患者S-100β蛋白、神经元特异性烯醇化酶（NSE）水平及术后认知功能障碍（POCD）的影响。方法：选择择期骨科脊柱手术患者80例,ASA分级Ⅰ-Ⅱ级。按照随机数字表将患者分为AHH组和C组,每组40例。AHH组麻醉诱导后应用6%羟乙基淀粉130/0.4以20 ml/min速度行AHH,输注量为全身血容量的20%。C组不实施血液稀释,麻醉和手术方法与AHH组相同。记录两组术中出血量、异体输血量及尿量;于术前1 d、手术开始后1 h、术毕、术后12 h记录平均动脉压（MAP）、心率（HR）、中心静脉压（CVP）;于术前1 d、手术开始后15 min、手术开始后45 min、术毕检测动脉血氧含量（CaO₂）、静脉血氧含量（CjvO₂）、动静脉血氧含量差（Da-jvO₂）及脑氧摄取率（CERO₂）;于术前1 d,术后1、3、7 d行简易智能精神状态检查量表（MMSE）评分和S-100β蛋白、NSE水平测定。记录两组POCD发生率。结果：（1）AHH组术中出血量、输异体血量少于C组（P<0.05）,尿量多于C组（P<0.05）。（2）与术前1 d及C组同时间点比较,AHH组术毕时MAP［（75.6±4.1）mmHg］降低（P<0.05）;与术前1 d及C组同时间点比较,AHH组手术开始后1 h时CVP［（6.9±0.6）cmH₂O］升高（P<0.05）,但均在正常范围内。（3）与术前1 d及C组同时间点比较,AHH组手术开始后15 min、45 min、术毕时Da-jvO₂、CERO₂水平下降（P<0.05）。（4）与术前1 d比较,两组术后1 d的MMSE评分下降（P<0.05）,S-100β蛋白和NSE水平升高（P<0.05）,术后3、7 d有所恢复。两组间术后1 d的MMSE评分、S-100β蛋白和NSE水平差异有统计学意义（P<0.05）。（5）两组POCD发生率差异无统计学意义（P>0.05）。结论：AHH可明显减少老年脊柱手术患者的术中失血量和异体血输注量,降低S-100β蛋白和NSE水平,不增加POCD的发生风险。     

Presenteeism and Absenteeism Before and After Total Hip and Knee Arthroplasty

BackgroundAbsenteeism is costly, yet evidence suggests that presenteeism—illness-related reduced productivity at work—is costlier. We quantified employed patients’ presenteeism and absenteeism before and after total joint arthroplasty (TJA).MethodsWe measured presenteeism (0-100 scale, 100 full performance) and absenteeism using the World Health Organization’s Health and Work Performance Questionnaire before and after TJA among a convenience sample of employed patients. We captured detailed information about employment and job characteristics and evaluated how and among whom presenteeism and absenteeism improved.ResultsIn total, 636 primary, unilateral TJA patients responded to an enrollment email, confirmed employment, and completed a preoperative survey (mean age: 62.1 years, 55.3% women). Full at-work performance was reported by 19.7%. Among 520 (81.8%) who responded to a 1-year follow-up, 473 (91.0%) were still employed, and 461 (88.7%) had resumed working. Among patients reporting at baseline and 1 year, average at-work performance improved from 80.7 to 89.4. A Wilcoxon signed-rank test indicated that postoperative performance was significantly higher than preoperative performance (P < .0001). The percentage of patients who reported full at-work performance increased from 20.9% to 36.8% (delta = 15.9%, 95% confidence interval = [10.0%, 21.9%], P < .0001). Presenteeism gains were concentrated among patients who reported declining work performance leading up to surgery. Average changes in absences were relatively small. Combined, the average monthly value lost by employers to presenteeism declined from 15.3% to 8.3% and to absenteeism from 16.9% to 15.5% (ie, mitigated loss of 8.4% of monthly value).ConclusionAmong employed patients before TJA, presenteeism and absenteeism were similarly costly. After, employed patients reported increased performance, concentrated among those with declining performance leading up to surgery.     

The German emergency and disaster medicine and management systemdhistory and present

As well for optimized emergency management in individual cases as for optimized mass medicine in disaster management, the principle of the medical doctors approaching the patient directly and timely, even close to the site of the incident, is a long-standing marker for quality of care and patient survival in Germany. Professional rescue and emergency forces, including medical services, are the “Golden Standard” of emergency management systems. Regulative laws, proper organization of resources, equipment, training and adequate delivery of medical measures are key factors in systematic approaches to manage emergencies and disasters alike and thus save lives. During disasters command, communication, coordination and cooperation are essential to cope with extreme situations, even more so in a globalized world. In this article, we describe the major historical milestones, the current state of the German system in emergency and disaster management and its integration into the broader European approach.     

Differences in Osteocyte Density and Bone Histomorphometry Between Men and Women and Between Healthy and Osteoporotic Subjects

Bone defects related to osteoporosis develop with increasing age and differ between males and females. It is currently thought that the bone remodeling process is supervised by osteocytes in a strain-dependent manner. We have shown an altered response of osteocytes from osteoporotic patients to mechanical loading, and osteocyte density is reduced in osteoporotic patients, which might relate to imperfect bone remodeling, leading to lack of bone mass and strength. Hence, information on osteocyte density will contribute to a better understanding of bone biology in males and females and to the assessment of osteoporosis. Osteocyte density as well as conventional histomorphometric parameters of trabecular bone were determined in cancellous iliac crest bone of healthy postmenopausal women and men and of osteoporotic women and men. Osteocyte density was higher in healthy females than in healthy males and lower in osteoporotic females than in healthy females. Bone mass was reduced in osteoporotic patients, both male and female. In females, trabecular number was reduced, whereas in males, trabecular thickness was reduced and eroded surface was increased. There were no correlations between the parameter groups bone architecture, bone formation, bone resorption, and osteocyte density. These results are consistent with impaired osteoblast function in osteoporotic patients and with a different mechanism of bone loss between men and women, in which osteocyte density might play a role. The reduced osteocyte numbers in female osteoporotic patients might relate to imperfect bone remodeling leading to lack of bone mass and strength. M. G. Mullender and S. D. Tan contributed equally to this work.     

Tendon and Ligament Healing and Current Approaches to Tendon and Ligament Regeneration

Ligament and tendon injuries are common problems in orthopedics. There is a need for treatments that can expedite nonoperative healing or improve the efficacy of surgical repair or reconstruction of ligaments and tendons. Successful biologically-based attempts at repair and reconstruction would require a thorough understanding of normal tendon and ligament healing. The inflammatory, proliferative, and remodeling phases, and the cells involved in tendon and ligament healing will be reviewed. Then, current research efforts focusing on biologically-based treatments of ligament and tendon injuries will be summarized, with a focus on stem cells endogenous to tendons and ligaments. Statement of clinical significance: This paper details mechanisms of ligament and tendon healing, as well as attempts to apply stem cells to ligament and tendon healing. Understanding of these topics could lead to more efficacious therapies to treat ligament and tendon injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:7–12, 2020