外固定支架联合Kapandji技术微创治疗老年桡骨远端不稳定骨折

目的探讨外固定支架联合Kapandji技术治疗老年桡骨远端不稳定骨折的疗效。方法2012年5月~2016年2月对21例老年桡骨远端不稳定骨折(按AO分型:A3型6例,B2型3例,C2型9例,C3型3例)采用外固定支架联合克氏针经皮插入以阻挡骨块再移位的Kapandji技术。末次随访根据改良的Sarmiento评分进行影像学评估,根据Gartland-Werley功能评分标准进行腕关节功能评估。结果手术时间25~45 min,平均35.3 min。术后住院时间3~14 d,平均6.5 d。21例随访8~24个月,平均15.3月,骨折均获愈合。影像学评分:优17例,良4例;腕关节功能评分:优13例,良5例,可3例,优良率为85.7%(18/21)。结论外固定支架联合Kapandji技术是老年桡骨远端不稳定骨折有效的微创手术方法,易于操作,避免伸肌腱的刺激,可有效增强固定的稳定性,功能恢复良好。     

肘关节恐怖三联征中桡骨小头HotchkissⅢ型骨折的处理策略选择：内固定或置换?

目的 探讨保留桡骨小头内固定和桡骨小头假体置换治疗肘关节恐怖三联征中桡骨小头Hotchkiss Ⅲ型骨折的临床疗效,并为该类骨折的处理策略选择提供科学依据。方法 对在我院行手术治疗的23例伴桡骨小头HotchkissⅢ型骨折的恐怖三联征患者的临床资料行回顾性分析,对患者就桡骨小头的处理方式进行分组,其中10例行保留桡骨小头的切开复位内固定者为内固定组,13例行桡骨小头切除后行桡骨小头假体置换者为置换组。对所有患者行至少1年,结合手术相关指标、肘关节功能评分、成本-效益分析、患者满意度及生活质量等综合分析两种方案处理恐怖三联征中桡骨小头Hotchkiss Ⅲ型骨折的医疗、经济效益并作比较评价。结果 手术时间内固定组长于置换组（P<0.05）,切口长度、术后当天疼痛评分两组无统计学差异（P>0.05）,术后1年复查,患者Mayo肘关节功能评分示,置换组总分优于内固定组（P<0.05）,其中其肘关节疼痛、功能范围恢复均优于内固定组（P<0.05）,但两组稳定性、日常活动完成情况评分对比数据无统计学差异（P>0.05）,两组患者治疗质量-效益分析显示,内固定组治疗费用低于置换组（P<0.05）,治疗效益、患者满意度均高于置换组（P<0.05）,术后1年生活质量对比两组数据差异无统计学意义（P>0.05）。结论 两种方法均能有效治疗TTE中该类复杂骨折,从而恢复肘关节日常功能,改善生活质量。桡骨小头置换术创伤较小,功能改善较优,但内固定术治疗效益及患者满意度更高。     

Gamma钉治疗股骨转子间骨折远端是否锁钉疗效比较

目的探讨Gamma钉内固定治疗股骨转子间骨折远端是否锁钉对疗效的影响。方法对144例稳定性股骨转子间骨折患者采用Gamma钉内固定,根据远端锁钉与否将患者分为远端未采用锁钉组(非锁钉组,70例)和远端采用锁钉组(锁钉组,74例)。观察两组患者手术时间、透视时间、输血量、住院时间、骨折复位质量、骨折愈合时间及并发症。结果两组均获得12个月随访。两组骨折复位质量、住院时间、骨折愈合时间比较差异无统计学意义(P>0.05)。手术时间、术中透视时间、输血量锁钉组明显长(多)于非锁钉组(P<0.001)。两组患者并发症发生率比较差异无统计学意义(P>0.05)。结论采用Gamma钉治疗稳定性股骨转子间骨折远端可以不行锁钉固定,不影响骨折愈合和临床疗效,还具有减少透视时间、手术时间、术后并发症等优点。     

克氏针钢丝与髌骨针钛缆两种张力带固定治疗髌骨骨折

目的比较克氏针钢丝与髌骨针钛缆张力带固定治疗髌骨骨折的疗效。方法将128例髌骨骨折患者按固定方式分为A组(克氏针钢丝张力带固定,65例)和B组(髌骨针钛缆张力带固定,63例)。比较两组住院费用、住院天数、并发症发生率以及关节功能优良率。结果患者均获得随访,时间12~24个月。两组住院费用、住院天数、并发症发生率比较差异均有统计学意义(P<0.05)。两组关节功能优良率比较差异无统计学意义(P>0.05)。结论克氏针钢丝张力带固定术后并发症发生率较高,但关节功能优良率与髌骨针钛缆张力带固定比较无明显差异,且具有缩短住院时间、降低住院费用等优点。     

股骨转子下骨折术后不愈合并内固定断裂1例

患者,女,69岁,既往高血压病史,慢性胃溃疡30余年,无糖尿病、冠心病、肝炎等病史。患者于13个月前从约1.5 m高处摔落致右大腿上部疼痛肿胀,伴髋部活动受限,在当地医院行X线检查,诊断为右股骨转子下骨折,AO分型32-A2型(见图1A)。于当地医院行切开复位动力髋螺钉内固定术治疗,术后X线片显示对位对线良好(见图1B)。术后患者能缓慢行走,定期当地门诊复查,见折端骨痂生长,但愈合迟缓,右侧股骨有逐渐内翻趋势。3 d前晨起时突发右侧大腿疼痛肿胀,中段可扪及异物感,行走困难,遂于2017年1月20日至我院门诊就诊。行X线检查提示:右股骨转子下骨折,内固定术后改变,折端部分愈合,股骨上段内固定钢板外移,螺钉断裂(见图1C)。     

空心钉与空心钉钢板内固定治疗股骨颈骨折疗效比较

目的比较空心钉与空心钉钢板内固定治疗股骨颈骨折的疗效。方法将68例股骨颈骨折患者根据治疗方式分为空心钉组(37例)和空心钉钢板组(31例)。比较两组切口长度、手术时间、术中出血量、并发症、骨折愈合率和术后6个月髋关节Harris评分。结果手术切口均一期愈合。切口长度、手术时间、术中出血量空心钉组均少(短)于空心钉钢板组(P<0.05)。两组患者均获得随访,时间6~41(21.7±10.8)个月。术后6个月,股骨头坏死及骨折不愈合例数空心钉组均多于空心钉钢板组,但差异无统计学意义(P>0.05);股骨颈短缩及螺钉松动、退出例数空心钉组均多于空心钉钢板组,差异有统计学意义(P<0.05);髋关节Harris评分空心钉组低于空心钉钢板组(P<0.05)。结论空心钉和空心钉钢板内固定治疗股骨颈骨折均可获得较好的临床疗效,空心钉钢板内固定能获得更加稳固的支撑,对患肢早期功能锻炼更有利。     

Implant surface alters compartmental-specific contributions to fixation strength in rats

Mechanical fixation of the implant to host bone is an important contributor to orthopedic implant survivorship. The relative importance of bone-implant contact, trabecular bone architecture, and cortical bone geometry to implant fixation strength has never been directly tested, especially in the settings of differential implant surface properties. Thus, using a rat model where titanium rods were placed into the intramedullary canal of the distal femur, we determined the relative contribution of bone-implant contact and peri-implant bone architecture to the fixation strength in implants with different surface roughness: highly polished and smooth (as-received) and dual acid-etched (DAE) implants. Using a training set that maximized variance in implant fixation strength, we initially examined correlation between implant fixation strength and outcome parameters from microcomputed tomography and found that osseointegration volume per total volume (OV/TV), trabecular bone volume per total volume (BV/TV), and cortical thickness (Ct.Th) were the single best compartment-specific predictors of fixation strength. We defined separate regression models to predict implant fixation strength for as-received and DAE implants. When the training set models were applied to independent validation sets, we found strong correlations between predicted and experimentally measured implant fixation strength, with r² = .843 in as received and r² = .825 in DAE implants. Interestingly, for as-received implants, OV/TV explained more of the total variance in implant fixation strength than the other variables, whereas in DAE implants, Ct.Th had the most explanatory power, suggesting that surface topography of implants affects which bone compartment is most important in providing implant fixation strength.     

Accuracy of EBRA-cup measurements after reconstruction of severe acetabular defects at revision THR

Radiostereometric analysis (RSA) is the most accurate method of measuring component migration using radiographs but is restricted to use in prospective studies. Ein-Bild-Roentgen-analyze (EBRA)-Cup can be used retrospectively, but its accuracy to measure component migration following revision is unknown. This study aimed to determine the accuracy of EBRA-Cup measurements of uncemented acetabular component migration after revision total hip replacement (THR). The secondary aim was to compare the number of cases identified using EBRA-Cup and RSA as having proximally migrated above and below 1 mm at 2 years postoperatively. EBRA-Cup measurements were performed on plain antero-posterior pelvic radiographs taken at the same time as RSA radiographs in a prospective cohort of 53 hips undergoing acetabular revision. At 2 years, the mean difference between the RSA and EBRA-Cup measurements for 17 components used to treat pelvic discontinuity was 0.90 mm, significantly greater than the mean difference of 0.28 mm for 36 components without discontinuity (P = .0001). The mean difference between the RSA and EBRA-Cup measurements at 2 years for hips that were reconstructed with an acetabular component alone, 0.28 mm, was significantly lower than hips that were reconstructed with an acetabular component in combination with an augment and/or cage, 0.74 mm (P = .0005). In conclusion, EBRA-Cup can accurately measure migration of uncemented acetabular components used at revision THR. The presence of pelvic discontinuity, and addition of augments and cages, significantly influenced the accuracy of EBRA-Cup measurements. EBRA-Cup and RSA had good agreement on classification of components that migrated proximally above or below 1 mm at 2 years, with 100% sensitivity, and 87% specificity.     

Similitude of cement-bone micromechanics in cemented rat and human knee replacement

A preclinical rat knee replacement model was recently developed to explore the biological and mechanobiological changes of trabecular resorption for cement-bone interdigitated regions. The goal here was to evaluate the relevance of this model compared with human knee replacement with regards to functional micromechanics. Eight nonsurvival, cemented knee replacement surgeries were performed, the interdigitated gap morphology was quantified, and interface micromotion between cement and bone was measured for 1 to 5 bodyweight loading. Computational fluid dynamics modeling of unit cell geometries with small gaps between trabeculae and cement was used to estimate fluid flow. Gap width (3.6 μm) was substantially smaller compared with cement-bone gaps reported in human knee replacement (11.8 μm). Micromotion at the cement-bone border was also decreased for the rat knee replacement (0.48 μm), compared with human (1.97 μm), for 1 bodyweight loading. However, the micromotion-to-gap width ratio (0.19 and 0.22 for, rat and human), and estimated fluid shear stress (6.47 and 7.13 Pa, for rat and human) were similar. Replicating the fluid dynamic characteristics of cement-bone interdigitated regions in human knee replacements using preclinical models may be important to recapitulate trabecular resorption mechanisms due to proposed supraphysiologic fluid shear stress. Statement of clinical significance: local cement-bone micromotion due to joint loading may contribute to the process of clinical loosening in total joint replacements. This work shows that while micromotion and gap morphology are diminished for the rat knee model compared to human, the motion-to-gap ratio, and corresponding fluid shear stress are of similar magnitudes