计算机手术导航系统对股骨头表面假体植入精确度的研究

目的研究非影像手术导航系统对股骨头表面假体植入位置的影响。方法25例股骨头坏死患者（共32髋）。其中男性16例，女性9例，年龄（36±7）岁。随机分为2组，计算机导航手术组（导航组）11例（16髋），在导航系统下进行股骨头表面置换术，设定髋最佳植入柄颈角为0°，柄干角为140°；对照组14例（16髋）采用传统手术。术后测定假体植入的角度，进行手术评估。结果术后导航组植入股骨假体柄干角为（140．5±1．7）°，对照组为（135．9±6．5）°，导航组的股骨假体柄颈角为（O．30±1．40）°，对照组柄颈角为（-4．93±4．30）°，两组差异具有统计学意义（P〈0．05）。Harris评分，导航组优14髋，良2髋；对照组优9髋，良4髋，中3髋。导航组无一例发生肢体缩短、旋转、内外翻畸形，对照组2例发生短缩畸形，1例内翻15°畸形。随访（14±4）个月，均无假体松动、脱位。结论在非影像手术导航系统下手术操作可以精确地植入假体，减少假体松动的发生,具有重要的临床价值。     

Preoperative tibiofemoral rotational alignment is a risk factor for component rotational mismatch in total knee arthroplasty

BackgroundRotational mismatch between the femoral and tibial components is reported to be a risk factor for unsuccessful total knee arthroplasty (TKA). However, the rotational mismatch can still occur even when each component is aligned within the desired angle. Therefore, there may be other unknown factors. This study aims to investigate a risk factor for component rotational mismatch in TKA. The authors hypothesized a significant correlation between the rotational mismatch angle and not only the rotational alignments of components, but also the preoperative tibiofemoral rotation angle.MethodThis retrospective cohort study included 79 knees who underwent TKA. Computed tomography images were obtained preoperatively and 2 weeks after surgery for the component positional measurement. The postoperative component rotational mismatch angle between the tibial and femoral components and the rotational alignment of each tibial and femoral component to anatomical axes was evaluated. In addition, the preoperative rotational angle between the tibia and femur bones and patients’ demographics were also investigated. The correlation between the postoperative component rotational mismatch angle and perioperative variables was analyzed to identify risk factors for component rotational mismatch.ResultsThe mean component rotational mismatch angle was 1.8° of internal rotation of the tibial component relative to the femoral component, and the angle ranged from 11.3° of internal rotation to 7.3° of external rotation of the tibial component. Multivariate regression analysis showed that the preoperative rotational alignment between the tibia and femur and the rotational alignment of each component were influential factors in the postoperative component rotational mismatch angle.ConclusionThe preoperative tibiofemoral rotational alignment and the rotational alignment of each tibial and femoral component and are risk factors for the postoperative component rotational mismatch in TKA.     

Accuracy of implantation during computer-assisted minimally invasive Oxford unicompartmental knee arthroplasty: A comparison with a conventional instrumented technique

The prognosis of unicompartmental knee arthroplasty (UKA) is strongly associated with the accuracy of the component alignment. To determine the accuracy of navigated UKA during primary minimally invasive Oxford UKA, twenty-nine knees of 29 consecutive patients (Group A) implanted using conventional instrumented UKA were followed by 23 knees of 17 consecutive patients (Group B) implanted by navigation assisted UKA and radiological results regarding alignments of the femorotibial mechanical axis, femur, and tibial component were compared in the two groups. Assessments of mechanical limb alignment revealed statistically significant increases in mechanical limb alignment post-operatively in both groups (p = 0.0 for both). In terms of component alignment, Group B had more prostheses implanted in the satisfactory range (> ± 3° from the targeted values) for the femoral and tibial components than Group A. There were no significant differences in the rate of prosthesis implanted within the range of radiographic alignment variations for the coronal implantation of either femoral or tibial components in both groups. (Radiographic alignment variation; coronal orientation of femoral components 90 ± 10°, sagittal orientation of femoral components 90 ± 5°, coronal orientation of tibial components from 10° varus to 5° valgus, sagittal orientation of tibial components from 7° of posterior tibial flexion to 5° of anterior tibial flexion). However, significant increases in the accuracies of sagittal implantation of femoral and tibial components were observed in Group B versus Group A. Our data suggest that navigated implantation improves the accuracy of the radiological implantation of the Oxford UKA prosthesis without increasing complications versus conventional UKA.     

个性化定制股骨截骨导板在单髁置换中精确性的实验研究

目的 探讨个性化定制股骨截骨导板在股骨标本单髁置换(UKA)术中应用的可行性和准确性,为临床应用提供实验性依据。方法 2016年1月—2017年2月选取复旦大学医学院解剖教研室成人股骨标本40根,男性22根、女性18根,年龄35~78岁,身高152~178 cm。采用数字表法随机分为导板组和对照组,每组20例。导板组采用个性化定制股骨截骨导板辅助UKA手术,术前采用薄层CT扫描对股骨进行医学图像数据采集,然后利用3D反求技术进行导航模板的设计,再采用3D打印技术制造个性化定制股骨截骨导板,并进行UKA术。对照组在UKA术中采用传统定位截骨。手术均由同一组医疗小组完成。评估两组标本的股骨侧手术截骨时间,并采用影像学评价下股骨假体力线和假体位置。结果 导板组术中导板与股骨髁骨性解剖结构贴合紧密,无明显移动。导板组与对照组手术截骨时间分别为(3.31±0.56) min和(4.45±0.74) min(t=-5.500, P<0.01),股骨假体内/外翻角度分别为1.31°±0.86°和2.84°±1.58°(t=-3.789,P<0.01),股骨假体后倾角度分别为8.84°±0.60°和6.25°±1.96°(t=5.661,P<0.01),差异均有统计学意义。导板组的股骨假体内/外翻角及后倾角更接近0°和10°,并且离散度小。结论 个性化定制股骨截骨导板用于UKA术能提高股骨假体冠状位和矢状位力线的精确性,缩短手术时间。     

Varus/valgus alignment of the femoral component in total knee arthroplasty

The position of the femoral component in 362 total knee replacements was assessed radiologically. A subgroup of 32 knees, 18 of which had perfect alignment and 14 with imperfect alignment underwent CT scout scans of the femur from which the mechanical axis of the femur could be measured. Radiologically 92% of all components were implanted within 3 degrees of the target value. There was close correlation between the CT and X-ray measurements in the subgroup. Deviation from the mechanical axis was 1.16 degrees (range -2.5 to +2) in the perfectly aligned knees, validating both surgical technique and radiological assessment. Causes for inaccuracy in femoral placement and future likely developments are discussed.     

Post traumatic knee arthritis: Navigated total knee replacement without hardware removal

BackgroundThe Authors present the results of a series of navigated total knee replacements (TKR) without hardware removal in patients with post-traumatic arthritis following femoral fractures. The purpose of the paper was to determine the effectiveness of computer-assisted TKR in these patients compared to routine primary implants.MethodsSixteen patients with post-traumatic knee arthritis following a distal femoral fracture and retained hardware were included in the study (group I). Patients in the study group were matched with patients who had undergone a computer navigated TKR using the same implant and software (group II). The indication for TKR in all group II patients was atraumatic arthritis and surgery was performed in the same period as the study group. Patients were matched for age, gender, pre-operative range of motion, severity of arthritis pre-operatively, type and grade of deformity and implant features.ResultsThere were no statistically significant differences in surgical time, hospital staying or intra-operative and post-operative complications between the two study groups. At the latest follow-up no statistically significant difference was seen for the Knee Society Score and WOMAC indices. Implant alignment and radiological parameters were similar in both groups.ConclusionsThis study demonstrated that post-traumatic knee arthritis following prior distal femoral fracture can be safely managed using a computer navigated TKR without hardware removal. Comparison between this patient group and a matched group with atraumatic arthritis showed similar post-operative results and complication rates.Level of evidence: III.     

新型定位装置在股骨颈骨折空心螺钉内固定中的辅助定位

文题释义：股骨颈骨折：多见于中老年人,青壮年可因高暴力损伤引起该类型骨折。骨折后患者髋部疼痛、肿胀,大转子处可有压痛及叩击痛,下肢存在短缩、内收、外旋等畸形。影像学检查可清晰地显示骨折的部位、类型及移位程度。 克氏针定位装置：该辅助定位装置适用于股骨颈骨折闭合复位空心螺钉内固定,与传统徒手操作相比,具有定位效率高、透视次数少、手术时间短、患者创伤小等优点;与骨科机器人、计算机导航系统等辅助定位装置相比,精确度有待提高,较适用于广大基层医院。 背景：目前骨科机器人、计算机导航系统等智能定位装置在股骨颈骨折闭合复位手术过程中的应用逐步开展,但基层医院仍需一种廉价的辅助定位装置。 目的：探讨一种股骨颈克氏针定位装置在股骨颈骨折空心螺钉内固定过程中辅助定位的效果。 方法：回顾性分析2016年2月至2018年3月滨州医学院附属医院收治的54例股骨颈骨折患者的临床资料,根据有无辅助定位装置分为2组,徒手定位组28例患者行传统徒手定位空心钉内固定;辅助定位组26例患者术中应用克氏针定位装置,定位针角度、方向、距离均可量化微调,辅助定位,引导置入空心螺钉。比较2组患者临床与影像资料。 结果与结论：①所有患者手术顺利,未发生血管、神经损伤等术中并发症;术后影像显示骨折复位良好,空心螺钉分布、角度、位置良好;②辅助复位组手术时间(49.27±4.86) min小于徒手定位组(59.64±8.02) min,差异有显著性意义(P < 0.01);辅助定位组透视次数明显少于徒手定位组,差异有显著性意义(P < 0.01);③2组随访时间、骨折愈合时间、末次随访Harris功能评分差异均无显著性意义(P > 0.05);辅助定位组Harris评分优良率为89%;④2组患者随访期间无股骨头坏死发生,晚期坏死率待随访;⑤提示克氏针定位装置在股骨颈骨折空心螺钉内固定过程中,可辅助定位,引导置入空心螺钉,能有效提高定位效率,减少透视次数,避免反复调整穿针对股骨颈骨质的损伤,促进患者恢复。 ORCID: 0000-0002-4576-3306(杜刚强) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

计算机导航在全膝关节置换中的应用

文题释义： 导航下全膝关节置换：术中在患肢股骨侧及胫骨侧分别安装红外线反射球，通过红外线原理将信息传输到计算机里面，通过计算机重建患者的下肢力线及空间结构，从而指导医师正确截骨。该系统能降低医生的主观判断产生的失误，能够提高假体植入的准确性，改善患者膝关节功能及提高假体使用寿命。 导航的优势：与传统膝关节置换手术相比，导航下膝关节置换能够提高术后下肢力线的准确性；能够有更好的伸屈间隙平衡；且术中不要打开股骨髓腔，减少了术后引流量。 背景：随着精准医疗的发展，导航下膝关节置换越来越受到重视，其能够使假体植入更加准确，获得有更好精确的下肢力线，但同时也延长了手术时间。 目的：探讨Aesculap Ortho-Pilot非影像依赖无线导航在全膝关节置换中的应用价值。 方法：回顾性收集2017年4至11月安徽医科大学第一附属医院收治的42例单侧膝关节骨性关节炎患者病历资料，经同一手术医师完成初次全膝关节置换，按照手术方式分为2组：导航组在Ortho-Pilot非影像依赖无线导航辅助下进行全膝关节置换，非导航组进行常规的全膝关节置换，每组21例。记录两组手术时间、术后引流量；术后12个月拍摄负重X射线片，观察下肢机械轴线、胫骨机械轴近端内侧角、股骨机械轴远端外侧角、矢状面胫骨组件角与下肢力线偏差>3°的患者数量，同时评估患者膝关节活动度与膝关节功能HSS评分。试验获得安徽医科大学第一附属医院伦理委员会批准。 结果与结论：①导航组手术时间长于非导航组(P < 0.05)，术后引流量少于非导航组(P < 0.05)；②术后12个月，导航组下肢机械轴线、股骨机械轴远端外侧角、矢状面胫骨组件角分离变量的误差均小于非导航组(P < 0.05)，两组胫骨机械轴近端内侧角分离变量与下肢力线>3°的病例数比较差异无显著性意义(P > 0.05)；③术后12个月，导航组膝关节活动度大于非导航组(P < 0.05)，两组膝关节功能HSS评分比较差异无显著性意义(P > 0.05)；④结果表明，计算机导航辅助全膝关节置换能够提高下肢力线的准确性、假体安放的准确性及膝关节活动度，但增加了手术时间，应用时应综合考虑其利弊。 ORCID: 0000-0003-1243-9574(江正) 中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程     

计算机导航辅助全膝关节置换定位与软组织平衡

BACKGROUND: Computer assisted navigation has been applied in total knee arthroplasty, can make the prosthesis more accurately implanted, play a good role in navigation, and enhance accuracy of knee prosthesis rotation power lines. Computer-assisted navigation system appears lately in China, so few studies concern the location of total knee arthroplasty and its application in soft tissue balance. OBJECTIVE: To investigate the application of computer navigation aids located in artificial total knee arthroplasty and soft tissue balance. METHODS: A total of 40 patients (49 knees) who received total knee arthroplasty in Department of Orthopeadic Surgery of Jincheng People’s Hospital from January to September 2015 were analyzed. The patients were divided into conventional surgery group (20 cases, 24 knees) and navigation group (20 cases, 25 knees). The patients in the conventional surgery group were positioned with intramedullary femoral alignment bar and extramedullary tibial alignment bar. In the navigation group, total knee arthroplasty was performed in accordance with computer. Repair of incision and approach in both groups were identical. Positioning effect and effect of computer assisted navigation on soft tissue balance in total knee arthroplasty were analyzed. RESULTS AND CONCLUSION: (1) Operation time was longer significantly in the navigation group than in the conventional surgery group (P < 0.05). Blood loss and 24-hour drainage volume were significantly less in the navigation group than in the conventional surgery group (P < 0.05). (2) Range of motion of the knee and Hospital for Special Surgery score were significantly higher in the navigation group than in the conventional surgery group (P < 0.05). Power line error, soft tissue balance angle variable and soft tissue balance separation variables were significantly less in the navigation group than in the conventional surgery group (P < 0.05). (3) These results confirmed that computer navigation aids in total knee arthroplasty obtained ideal effect, ensured more accurate prosthesis implantation, better limb alignment, and ensured soft tissue balance. However, the computer-assisted navigation will increase operation time. For its application, we should consider the pros and cons.        

Preliminary experience with electromagnetic navigation system in TKA

Accuracy of implant positioning and precise reconstruction of leg alignment offers the best way to achieve good long-term results in total knee arthroplasty. Computer instrumentation was developed to improve the final position of the component and restore the mechanical axis. Current navigation systems use either optical or electromagnetic tracking. The advantage of the Electromagnetic (EM) navigation system is that no line-of-sight issues are present. However, special iron-free instruments are required. This report analyzes the postoperative radiological results of 32 knees treated using an EM system. All the measurements were recorded using software able to subtend angles automatically by five physicians, three radiologist and two orthopedic residents not involved with the surgery. Each radiograph was measured three times, in random order, and at delayed intervals. We found an ideal alignment for the mechanical axis (180+/-3 degrees ) in 30 out of 32 cases, whereas all the patients achieved a value of 90 degrees +/-3 degrees for both femoral and tibial frontal component angles. An apparently over-corrected implant position for the sagittal femoral component was reported, with a mean value of 11.2 degrees +/-3.6. The mean position of the tibial component was 90.6 degrees +/-2.8; just four measurements were outside of the +/-3 degrees of the desired value. EM is safe and there were no complications related to this system. An almost perfect correlation was found between the mechanical axis value of the EM navigation system (179.8 degrees +/-1.8) and the median value of the all reviewers (180.3 degrees +/-1.9) with a difference of 0.5 degrees .     

Influence of component alignment on outcome for unicompartmental knee replacement

This study's aim was to assess the effect of component mal-alignment on outcome of Oxford Unicompartmental Knee Replacement (UKR). Two hundred and eleven knees implanted with a medial UKR, using a minimally invasive approach, were followed up at a minimum of 4 years. Sagittal and frontal plane femoral and tibial component alignments were determined from antero-posterior and lateral radiographs. The cohort was divided into alignment groups which represented consecutive 2.5° intervals over the range of measured values for femoral varus/valgus, femoral flexion/extension, tibial varus/valgus and tibial tilt. The Oxford Knee Score (OKS) and incidence of radiolucency (RL) were compared between alignment groups for each alignment parameter. In 98% of cases the femoral components were positioned between 10° varus and 10° valgus; all femoral components were within ± 10° flexion. In 92% of cases the tibial components were positioned between ± 5° varus/valgus and superior/inferior tilt (neutral tilt being 7°). Within these ranges there were no significant differences in OKS or RL between the alignment groups; nor were there any differences between those at the extremes of component alignment compared to those in the inner ranges of alignment. We conclude that, because of the spherical femoral component, the Oxford UKR is tolerant to femoral mal-alignment of 10° and tibial mal-alignment of 5°.     

Preliminary radiological evaluation of the Vector Vision CT-free knee module for implantation of the LCS knee prosthesis

We have assessed the bone cuts achieved at surgery as compared to the planned cuts produced during computer assisted surgery (CAS) using a CT-free navigation system. In addition, two groups of matched patients were compared to assess the post-operative mechanical alignment achieved. Fourteen patients received a LCS total knee replacement (TKR) using the Vector Vision module and 14 received a TKR using a conventional method of extramedullary alignment jigs. The deviation in each plane (valgus-varus, flexion-extension and proximal-distal) was calculated. For the tibia the mean deviation in coronal plane was 0.21 degrees of varus (SD=1.37) and in the sagittal plane was 1.29 degrees of flexion (SD=3.73) and 0.24 mm of resection distal to the anticipated cut (SD=2.14). For the femur the mean deviation in the coronal plane was 0.88 degrees (SD=2.2) of valgus and in the sagittal plane the mean deviation was 0.3 degrees (SD=2.91) of extension. In the transverse plane there was a mean deviation of 0.07 degrees (SD=1.57) of external rotation. There was a mean deviation of 2.33 mm of proximal resection (SD=2.9) and 1.05 mm of anterior shift (SD=2.81). On comparing the two groups, no statistically significant differences were found for the angles between the femoral component and the femoral mechanical axis, the tibial component and the tibial mechanical axis, the femoral and tibial mechanical axis and the femoral and tibial anatomical axis. This study has presented preliminary data regarding the efficacy of a particular navigation system with regards to improving upon the accuracy of component position with the long-term aspiration of improving upon TKR longevity. A further randomised controlled trial with greater numbers of cases and controls would improve upon our knowledge as to the efficacy of the Vector Vision system and a power analysis based upon the findings of this pilot study has suggested that at least thirty subjects be included in each group.     

Surgical epicondylar axis is not orthogonal to the femoral mechanical knee axis in valgus knees with primary osteoarthritis: Three-dimensional analysis according to knee coronal alignment in 112 patients

BackgroundDuring total knee arthroplasty (TKA), most surgeons align the femoral component along the surgical epicondylar axis (SEA) considering it as orthogonal to the femoral mechanical axis. However, it is still unclear how SEA coronal alignment varies according to the native coronal knee alignment. The main goal of this study was to analyze the SEA orientation according to the native coronal knee morphotype.MethodsA total of 112 patients underwent a three-dimensional (3D) -planning-based TKA. The SEA was then determined by locating the epicondyles on 3D models. The 3D femoral and tibial mechanical axes were marked and the femoral (FMA) and tibial (TMA) mechanical angles were measured. The native HKA angle was measured as FMA + TMA. The SEA orientation angles were measured in the coronal (SEA-α) and axial (SEA-β) plane. SEA orientation was compared between the valgus, neutral, and varus knees.ResultsThe mean SEA-α angle was 90.2 ± 3° and the mean axial SEA-β angle was 92.2 ± 1.3°. The SEA-α angle was significantly higher in the valgus group compared with the neutral group (92.3 ± 2.9°, 90 ± 2.9°, P = 0.0009) whereas there was no significant difference in the SEA-α angle between the varus and the neutral group (89.7 ± 2.3°, 90 ± 2.9°, P = 0.32).ConclusionsIn contrast to the neutral and varus knees, the SEA was not orthogonal to the femoral mechanical axis in patients undergoing TKA for primary osteoarthritis. Our results suggest adapting the coronal alignment of the femoral component during TKA, while maintaining an average 2° valgus in valgus knees. By contrast, with varus and neutral knees, our data support the use of a mechanical alignment.     

Variability in static alignment and kinematics for kinematically aligned TKA

Background

Total knee arthroplasty (TKA) significantly improves pain and restores a considerable degree of function. However, improvements are needed to increase patient satisfaction and restore kinematics to allow more physically demanding activities that active patients consider important. The aim of our study was to compare the alignment and motion of kinematically and mechanically aligned TKAs.

Natural distribution of the femoral mechanical-anatomical angle in an osteoarthritic population and its relevance to total knee arthroplasty

A common surgical goal in TKA is to restore neutral alignment of the lower limb by making bone cuts perpendicular to the mechanical axes of the femur and tibia. Standard practice for many surgeons is to use the same distal femoral valgus resection angle for all patients, assuming little or no variation in the femoral mechanical-anatomical (FMA) angle between different patients' knees. This study analysed 174 pre-operative hip-knee-ankle radiographs of osteoarthritic knees (157 patients, 87 female and 70 male, mean age 70years and mean BMI 31.8). Measurements of mechanical femorotibial (MFT) and FMA angles were made. The mean FMA angle was 5.7° (SD 1.2°, range 2° to 9°). There was a statistically significant difference between the FMA angle for males and females with males tending to have larger FMA angles (p<0.001). There was a statistically significant correlation between MFT and FMA angle (r=-0.499) with varus knees tending to have larger FMA angles (p<0.001). These results indicate a wide distribution of FMA angle in an osteoarthritic population. In terms of achieving appropriate coronal alignment in TKA the use of a fixed valgus resection angle is not suitable for all patients and it may be preferable to adjust the distal femoral cut according to individual FMA angles. However if this angle is not available the cut may be adjusted according to pre-operative coronal alignment, using 6° for neutral/mild varus, >6° for more severe varus and <6° for valgus knees.     

Robotic-assisted total knee arthroplasty improves the outlier of rotational alignment of the tibial prosthesis using 3DCT measurements

BackgroundThe aim of the present study was to compare the accuracy of prosthetic alignment with three-dimensional computed tomography (3DCT) measurements following total knee arthroplasty (TKA) performed using a robotic-assisted surgical technique versus a conventional TKA.Methods41 TKAs were performed with a handheld robotic-assisted surgical procedure (Robot group) between 2019 and 2020. Another 41 patients underwent TKA with a conventional manual surgical procedure (Manual group) using the same prosthesis. The operation durations between both groups were investigated. 3DCT scans of the entire lower extremities were taken before and after the surgery and femoral and tibial alignments in the coronal, sagittal, and axial planes were measured using computer software. The differences in prosthetic alignment and translation between the preoperative 3DCT plan and postoperative 3DCT image were also measured.ResultsThere were no statistically significant differences in the post-operative outliers of the femorotibial angle between the groups. In the tibial-axial plane, the mean of prosthetic alignment in the anteroposterior plane was 4.0° in the Robot group and 6.7° in the Manual group (p < 0.01). The rate of outliers for tibial-axial alignment in the Robot group was significantly less than in the Manual group (p < 0.01). There were no statistically significant differences in prosthetic translation in the proximal-distal, anterior-posterior and medial-lateral orientations between the groups.ConclusionsIn a radiologic study using 3DCT, robotic-assisted TKA reduced the outliers for rotational alignment of the tibial prosthesis in comparison to conventional TKA, which can lead to improved tracking of the femoral-tibial bearing surfaces.     

Relationship of the posterior femoral axis of the “kinematically aligned” total knee arthroplasty to the posterior condylar,transepicondylar, and anteroposterior femoral axes

BackgroundA recent proposed modification in surgical technique in total knee arthroplasty (TKA) has been the introduction of the “kinematically aligned” TKA, in which the angle and level of the posterior joint line of the femoral component and joint line of the tibial component are aligned to those of the “normal,” pre-arthritic knee. The purpose of this study was to establish the relationship of the posterior femoral axis of the “kinematically aligned” total knee arthroplasty (TKA) to the traditional axes used to set femoral component rotation.MethodsOne hundred and fourteen consecutive, unselected patients with preoperative MRI images undergoing TKA were retrospectively reviewed. The transepicondylar axis (TEA), posterior condylar axis (PCA), antero-posterior axis (APA) of the trochlear groove, and posterior femoral axis of the kinematically aligned TKA (KAA) were templated on axial MRI images by two independent observers. The relationships between the KAA, TEA, APA, and PCA were determined, with a negative value indicating relative internal rotation of the axis.ResultsOn average, the KAA was 0.5° externally rotated relative to the PCA (minimum of − 3.6°, maximum of 5.8°), − 4.0° internally rotated relative to the TEA (minimum of − 10.5°, maximum of 2.3°), and − 96.4° internally rotated relative to the APA (minimum of − 104.5°, maximum of − 88.5°). Each of these relationships exhibited a wide range of potential values.ConclusionsUsing a kinematically aligned surgical technique internally rotates the posterior femoral axis relative to the transepicondylar axis, which significantly differs from current alignment instrument targets.     

The effect of component alignment on clinical outcomes in fixed bearing unicompartmental knee arthroplasty

BackgroundThe aim of this study is to report component alignment in a series of ZUK fixed bearing unicompartmental knee arthroplasty (UKA) implants and compare this to clinical outcomes.MethodsThe radiographs, Knee Society Scores (KSS) and knee flexion of 223 medial UKAs were evaluated. The following alignment parameters were assessed; coronal and sagittal femoral component angle (c-FCA and s-FCA), coronal and sagittal tibia component angle (c-TCA and s-TCA) and the coronal tibiofemoral angle (c-TFA). Each alignment parameter was grouped at consecutive 2.5° intervals, mean KSS and knee flexion was then compared between the interval groups.Results96.4% of femoral components were between 7.5° of varus and valgus and 95.1% between 7.5° extension and 5° flexion. 89.6% of tibial components were between 7.5° of varus and 2.5° valgus and 97.3% between 2.5° and 15° flexion. There was no significant difference between the KSS or knee flexion between any of the incremental groups of component alignment. Mean c-TFA was 0.2 ± 3.0°, 92.4% were between −5° (varus) and 5° (valgus). KSS were significantly greater for two of the increments with slightly more varus. Linear regression analysis showed there was very weak correlation (R² = 0.1933) between c-TFA and c-TCA.ConclusionsThe results of this study show that fixed bearing UKA components are forgiving to accommodate some variation in tibial and femoral component position without effecting clinical outcome scores or knee flexion. Limb alignment matters more than component position and knees with slight varus tibiofemoral alignment have better clinical scores than those with valgus.     

Significance of an insular component in follicular thyroid carcinoma with distant metastasis at initial presentation

Risk factors for distant metastasis were studied in 82 patients with follicular thyroid carcinoma (FTC). Metastases to either the lung or bone existing at the time of presentation were confirmed by I-131 radio-iodine uptake in 10 patients. FTC with an insular component was found in eight patients. Univariate analysis of 14 possible risk factors showed 7 to be statistically significant: insular component, poorly differentiated carcinoma, trabecular component, serum thyroglobulin level before surgery, patient age at the time of presentation, solid component, and vascular invasion (ranked by p values). After further analysis of the interrelation of the factors and of the logistic regression curves, we concluded that presence of an insular component and patient age were the only independent risk factors. Distant metastasis was not detected in any of the 27 patients ≤49 yr old. Among the 55 older patients (≥50 yr old), 5 of the 49 (10%) without an insular component and 5 of the 6 (83%) with an insular component had distant metastasis. The remaining older patient with an insular component but without distant metastasis showed a gradual increase in thyroglobulin levels after total thyroidectomy.     

数字化设计/显示技术辅助经皮椎体后凸成形术的应用研究

目的探讨数字化设计/显示技术辅助经皮椎体后凸成形术(D-PKP)对胸腰椎骨质疏松性椎体压缩骨折(OVCF)的临床疗效。方法选取2019年1月至2019年5月徐州医科大学附属淮安医院收治的25例采用经皮椎体后凸成形术(PKP)治疗的单节点高龄胸腰椎OVCF患者为研究对象,采用电脑随机抽样法随机分为数字化设计/显示技术辅助PKP组(D-PKP组)13例和常规PKP组(T-PKP组)12例。测量并比较2组患者手术时间、术中X射线透视次数、骨水泥灌注量、骨水泥与上/下终板最大接触比、骨水泥渗漏率、手术前后矢状位责任椎体后凸角、住院时间与术后12 h、1 d、1周、1个月的VAS和ODI,比较2组患者手术疗效。结果本研究2组患者骨水泥灌注量比较,差异无统计学意义(P>0.05);D-PKP组患者术后矢状位责任椎体后凸角、骨水泥与上/下终板最大接触比及骨水泥渗漏率明显优于T-PKP组,差异有统计学意义(P<0.05)。D-PKP组患者术中X射线透视次数少于T-PKP组,手术时间、住院时间短于T-PKP组,术后12 h、1 d的VAS和ODI优于T-PKP组,差异均具有统计学意义(P<0.05)。2组患者术后1周、1个月VAS与ODI比较,差异无统计学意义(P>0.05)。结论数字化设计/显示技术能够辅助PKP手术的精准实施,有助于提高OVCF的治疗效果。