Computed navigated total knee arthroplasty compared to computed tomography scans

Background

Successful total knee arthroplasty (TKA) includes accurate alignment. Controversy remains as to whether computer-navigated TKA improves the overall result and clinical outcome. Our aim is to compare the limb alignment and prosthesis positioning according to the pre- and postoperative computed tomography (CT) scans with the data collected from the navigation system.

Accuracy of a hand-held surgical navigation system for tibial resection in total knee arthroplasty

BackgroundAccuracy of total knee arthroplasty (TKA) implant placement and overall limb are important goals of TKA technique.MethodsThe accuracy and ease of use of an accelerometer-based hand-held navigation system for tibial resection during TKA was examined in 90 patients. Preoperative goals for sagittal alignment, navigation system assembly time, resection time, and tourniquet time were evaluated. Coronal and sagittal alignment was measured postoperatively.ResultsThe average coronal tibial component alignment was 0.43° valgus; 6.7% of patients had tibial coronal alignment outside of ± 3° varus/valgus. The difference between the intraoperative goal and radiographically measured posterior tibial slope was 0.5°. The average time to completion of the tibial cut was 4.6 minutes.ConclusionThe accelerometer-based hand-held navigation system was accurate for tibial coronal and sagittal alignment during TKA, with no additional surgical time compared with conventional instrumentation.     

单髁与后交叉韧带保留型假体膝关节置换的近期疗效对比

文题释义： 单髁置换：指对仅存在单间室病变膝关节的一种置换手术方式,用以替代膝关节胫股关节破坏的软骨表面,具有微创手术的优势,例如创伤小、恢复快、截骨少、费用低、手术时间短等优点。理论上,单髁置换后患者的膝关节活动度较好,且膝关节功能接近生理状态。 后交叉韧带保留型假体：全膝关节置换术中一种较为成熟的假体,术中保留了膝关节后交叉韧带且不进行髁间窝截骨,比较符合膝关节的解剖特性,手术难度虽然较大,但保留了较多的膝关节正常生理结构,有较好的膝关节稳定性,假体的松动率亦较低。背景：针对仅存在膝关节内侧间室病变的患者,单髁置换与后交叉韧带保留型全膝关节置换均是有效的治疗方式,但对于居住于山区的中老年人的近期疗效需进一步探索。 目的：探讨单髁置换与后交叉韧带保留型假体置换治疗承德地区中老年人膝关节内侧间室骨关节炎的近期疗效。 方法：选择2017年1月至2019年2月在承德医学院附属医院关节外科接受手术治疗的内侧间室膝关节炎中老年患者67例,其中A组31例行单髁置换,B组36例行后交叉韧带保留型假体全膝置换。所有患者对治疗方案均知情同意,且得到医院伦理委员会批准。观察比较2组患者术中出血量、术后输血情况、术后血红蛋白下降值,术后1,3 d红细胞容积、C-反应蛋白,术后第1,3,6个月及1年的关节遗忘评分。 结果与结论：①A组围术期血红蛋白下降值、术中出血量、输血率均低于B组,术后住院时间短于B组,差异有显著性意义(P < 0.05);②术后第1,3天2组的C-反应蛋白水平差异无显著性意义(P > 0.05);③A组术后第1,3,6月及1年的关节遗忘评分均高于B组,差异有显著性意义(P < 0.01);④2组术后均未发生下肢深静脉血栓、肺栓塞及感染等并发症;⑤综上,单髁置换在治疗仅存在内侧间室病变膝关节炎的山区中老年患者时,具有术中出血少、输血率低、关节遗忘程度高等优点。 ORCID: 0000-0002-8983-8293(韩梦光) 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     

Experience of total knee arthroplasty using a novel navigation system within the surgical field

Background

With the aim of improving component alignment and outcome in total knee arthroplasty (TKA), several computer-assisted devices (CAD) have been developed.

Comparison between highly cross-linked and conventional polyethylene in total knee arthroplasty

The use of highly cross-linked polyethylene in total knee prostheses is still controversial. The aim of the present study was to compare radiographic and clinical results of using conventional and highly cross-linked polyethylene in cruciate retaining total knee prostheses of completely the same design. Two hundred and two consecutive total knee arthroplasties (NexGen CR, Zimmer) were performed using the same procedure. The first consecutive 113 knees had conventional polyethylene insert and following consecutive 89 knees had highly cross-linked polyethylene insert (Prolong, Zimmer). Differences in the age, gender, and diagnosis between two groups were not statistically significant. Preoperative range of motion (ROM) of the knee, and Knee Society Score (KSS) was better in highly cross-linked polyethylene group. Clinical and radiographic results were evaluated at two years after operation. The difference of ROM and KSS between groups was not statistically significant. There was no revision surgery. No knee exhibited osteolysis, aseptic loosening, or polyethylene failure. There was no early catastrophic clinical failure due to use of the new material.     

膝关节置换手术导航系统精度测量方法及实现

目的：设计并实现了一种膝关节置换手术导航系统精度的精确检测方法,可对膝关节置换手术导航系统的参数进行测量与定量分析。方法：检测系统采用激光跟踪仪、定位靶球和骨锯模拟工装采集导航系统的定位平面空间坐标,依据定位靶球的空间位置计算得到导航系统的定位精度,实现了导航系统精度的精确检测。结果：本检测方法在某品牌的膝关节置换手术导航系统上进行了多次实验与分析,计算得到导航系统的定位位置准确度、定位位置重复性、定位姿态准确度、定位姿态重复性等检测数据,并对检测数据进行有效性分析。结论：本检测方法操作简洁,可重复性高,检测数据准确,可有效帮助技术人员完成导航系统的定位精度检测工作。     

Effect of improved navigation performance on the accuracy of implant placement in total hip arthroplasty with a CT-based navigation system

A computed tomography (CT)-based navigation system is one of the support tools to place implant with appropriate alignment and position in total hip arthroplasty (THA). To determine whether the higher performance of the navigation would further improve the accuracy of implant placement in the clinical setting, we retrospectively compared the navigation accuracy of two different versions of a navigation system. The newer version of the navigation system had an upgraded optical sensor with superior positional accuracy. Navigation accuracy, defined as differences between postoperative measurements on CT images and intraoperative records on the navigation system, of 49 THAs performed with the newer version of the navigation system was compared with that of 49 THAs performed with the older version. With the newer version, the mean absolute accuracy (95% limits of agreement) of implant alignment was 1.2° (±?3.3°) for cup inclination, 1.0° (±?2.4°) for cup anteversion, 2.0° (±?4.9°) for stem anteversion, and 1.1° (±?2.4°) for stem valgus angle. The accuracy of the implant position was 1.5 mm (±?3.1 mm), 1.3 mm (±?3.0 mm), and 1.5 mm (±?3.1 mm) for cup x-, y-, and z-axes, respectively, 1.6 mm (±?3.2 mm), 1.4 mm (±?2.9 mm), and 1.5 mm (±?2.7 mm) for stem x-, y-, and z-axes, respectively, and 2.4 mm (±?4.5 mm) for leg length discrepancy. The values for the newer version were significantly more accurate with less variation compared to those of the older version. With upgraded navigation performance, more accurate implant placement was demonstrated in the clinical setting.     

Forgotten Joint Score: Comparison between total and unicondylar knee arthroplasty

BackgroundThe aim of this study is to assess the Forgotten Joint Score (FJS) for total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA) with both short- and long-term follow-up.MethodsFor a consecutive period of eight months, the FJS was sent to all patients who had undergone either a primary TKA or UKA either one, five or ten years previously at our institution. Patient demographics and operative details were recorded retrospectively. FJS were collected for three different TKA prosthesis and two different UKA prosthesis.ResultsA total of 588 FJS questionnaires were completed consisting of 482 TKA and 106 UKA procedures.The mean FJS for patients with TKA and UKA were 50.2 and 65.4 respectively (p < 0.001). Mean FJS for the ZUK were statistically superior to the Oxford UKA, 73.1 versus 60.1 (p = 0.020). For TKA mean FJS were statistically better at five compared to one year follow up, 53.8 versus 44.8 (p = 0.007). For UKA the mean FJJs were greatest at 10 year follow up (69.0), but the difference between scores at one (60.4) and five (68.4) years was not statistically significant (p = 0.243).ConclusionThis cross-sectional study has shown; superior FJSs for UKA compared to TKA and superior FJSs for a fixed bearing compared to a mobile bearing UKA and therefore supports the use of UKA opposed to TKA where the indications for UKA are satisfied. For TKA the FJS in the five-year post-operative group were significantly superior to those in the one-year post-operative group.     

Improvement of activities of daily living after total hip arthroplasty using a computed tomography-based navigation system

The purpose of this study was to evaluate the outcome improvements after total hip arthroplasty (THA) using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in patients who underwent THA with a navigation system in our institutions. The subjects were 219 patients. All patients had adequate data to allow complete scoring of the WOMAC for a 1-year postoperative follow-up. CT-based navigation was used in all THAs. Postoperatively, no restrictions were imposed on patients’ ADL. One year after surgery, the average WOMAC pain subscale score was 1.8?±?2.9, the stiffness subscale score was 1.1?±?1.6, and the physical function subscale score was 7.5?±?11.6 points. The number of patients whose score for the WOMAC physical function score was 0 points was 61 (27.9%). A lower WOMAC score usually represents a better status. In some of the most difficult functions, such as ascending stairs, bending to the floor, putting on socks/stockings, and heavy domestic duties, the scores tended to be higher than the other scores postoperatively. These results show that THA using navigation can improve patients’ postoperative QOL.     

Intra- and interobserver reliability and agreement in three-dimensional computed tomography measurements of component positions after total knee arthroplasty

BackgroundAccurate evaluation of the postoperative position of total knee arthroplasty (TKA) components is crucial in the analysis of the association of alignments with clinical outcomes. The aim of this study was to investigate the reliability of measurements of component positions after TKA using three-dimensional computed tomography (3D-CT) reconstruction.MethodsTwo independent orthopedic surgeons (an attending surgeon and a fellow) examined 30 knees after primary TKA. The coronal, sagittal, and rotational positions of the femoral and tibial components were measured twice at an interval of six weeks on 3D-CT images reconstructed using ZedKnee software. Mean intra- and interobserver differences of measured angles were calculated, and the intra- and interobserver reliability was determined using intraclass correlation coefficients (ICCs), with agreement assessed by Bland–Altman analysis.ResultsThe mean intraobserver difference between alignment measurements for femoral and tibial components was < 2° (range 0.23–1.17°) and the mean interobserver difference was < 1° (range 0.22–0.97°). The intra- and interobserver ICCs were > 0.8 for all component positions. The only systematic bias found in the intra- and interobserver agreements occurred for the sagittal position of the femoral component.ConclusionThree-dimensional-CT measurements of component positions after TKA showed good intra- and interobserver reliability for the femoral and tibial components in coronal, sagittal and rotational positions. The intra- and interobserver agreements were favorable for all but the sagittal position of the femur. These results suggest that 3D-CT can be used to evaluate the alignment of all TKA components except for the sagittal position of the femur.     

Comparison of intraoperative kinematics and their influence on the clinical outcomes between posterior stabilized total knee arthroplasty and bi-cruciate stabilized total knee arthroplasty

BackgroundOf all the intraoperative kinematic parameters recorded using navigation systems, femorotibial rotational alignment is reportedly associated with the clinical outcomes of cruciate retaining and posterior stabilized (PS) total knee arthroplasty (TKA). However, to our knowledge, there are no reports on the relationship of newly designed bi-cruciate stabilized (BCS) TKA and intraoperative rotational kinematics. We aimed to clarify and compare the relationships between the intraoperative kinematics and clinical outcomes of BCS TKA and PS TKA.MethodsWe compared the intraoperative rotational kinematics and clinical outcomes at two years postoperatively of 56 BCS TKA patients and 55 PS TKA patients. Further, we evaluated the relationship between the femorotibial rotational kinematics and clinical outcomes.ResultsThe maximum flexion angle and the pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) in BCS TKA were significantly better than those in PS TKA. The intraoperative kinematic data of BCS TKA showed “screw-home” movement, while that of PS TKA did not show this movement. The rotational angular differences between at maximum flexion angle and at 60° flexion of BCS TKA showed positive correlations with the improvement of KOOS pain, symptom, activity of daily living and sports subscales. The rotational angular differences between at maximum flexion angle and at 30° flexion in PS TKA showed positive correlations with the maximum flexion angle.ConclusionIntraoperative femorotibial rotational kinematics and its influence on the clinical outcomes were different between BCS and PS TKA. BCS TKA showed more normal-like kinematics and better clinical results than PS TKA.     

Three-dimensional measurement technique to assess implant position and orientation after total knee arthroplasty

The performance of implant placement technologies are often evaluated based on their achieved post-operative implant alignment. Therefore accurate assessment techniques are necessary to compare pre-operatively planned implant positions with the corresponding post-operatively placed implant positions in total knee arthroplasty. This paper describes a CT based 3D measurement method for evaluation of implant positioning accuracy comparing post-operative implant position to the corresponding pre-operative planned implant position using 3D virtual models. TKAs were carried out on three phantoms and processed three times to investigate the accuracy of the method. The measurements were then assessed against measurements taken through an optical scan. The results indicate that an average measurement error less than 1 ° and 0.5 mm can be obtained except in the proximal–distal direction where the error was up to 1.34 mm. The accuracy of this 3D measurement technique is sufficiently reliable to enable reporting on implant position and orientation in the same coordinate system as pre-operatively defined independently of the planning system or the surgical implant placement technology (patient-specific guides, robotics, and navigation).     

全膝关节置换术与单髁置换术治疗膝关节单间室骨关节炎的疗效比较

目的 比较全膝关节置换术(TKA)与膝关节单髁置换术(UKA)治疗膝关节单间室骨关节炎的临床疗效。方法 对2012年3月—2015年3月徐州医科大学附属医院骨科88例行TKA或UKA治疗单间室骨关节炎并获得随访患者的临床资料进行回顾性分析,依据不同手术方法分为TKA组48例(48膝)和UKA组40例(40膝)。采用美国特种外科医院(HSS)膝关节评分,评价疗效。比较两组患者手术时间、术中出血量、术后引流量,术后第1天、3天、1周血红蛋白水平和术后第3天血红蛋白较术前的下降量,以及末次随访时关节活动度和疗效。结果 两组患者手术顺利,88例患者获随访6~36个月,平均20.25个月。TKA组手术时间(85.77±7.61)min多于UKA组的(80.50±6.82)min,术中出血量(103.54±17.68)mL多于UKA组的(74.75±11.82)mL,术后引流量(420.21±68.80)mL多于UKA组的(241.75±53.05)mL,差异均有统计学意义(t=3.389、t'=8.787、t'=13.411,P值均＜0.01)。两组术前血红蛋白水平差异无统计学意义(P＞0.05);TKA组术后第1天、3天、1周血红蛋白均低于UKA组,术后第3天血红蛋白较术前的下降量高于UKA组,差异均有统计学意义(P值均＜0.05)。UKA组术后膝关节屈曲至90°所需时间为(7.33±3.02)d,短于TKA组的(12.63±3.10)d(t=8.086,P＜0.01);末次随访UKA组患者膝关节屈曲角度为116.98°±13.71°,大于TKA组的125.13°±15.95°(t=2.576,P＜0.01)。TKA组和UKA组HSS评分优、良、可、差者分别为25、19、3、1例和23、15、2、0例,其优良率分别为91.67%(44/48)和95.00%(38/40),差异无统计学意义(Z=0.603,P＞0.05)。两组患者中仅TKA组发生深静脉血栓1例,经介入治疗后痊愈;其余患者无手术并发症发生。结论 UKA与TKA治疗膝关节单间室骨关节炎均能获得满意的临床疗效,但UKA具有出血少、手术时间短、功能恢复快等优点。     

The use of the knee joint-line balancer to control patella position in revision total knee arthroplasty

In revision total knee arthroplasty (TKA), control of the patellar height and the joint line is difficult. Therefore, we developed an adjustable flexion-extension spacer, the Knee Joint-line Balancer (KJB(R)). This device simulates femur component sizes, polyethylene sizes, the joint-line level, and distal femur wedges. The goal of this study is to evaluate the use of an adjustable knee spacer to control patellar height and joint-line during revision total knee surgery. The subjects of the study were the first 10 consecutive patients who had undergone revision of a primary TKA where the KJB was used. A reference group composed of the last 10 patients treated without the use of the KJB was also evaluated. The joint-line position and the patellar height were determined before and after revision TKA. The method described by Figgie et al. was used. The patellar height in the reference group averaged 7.7 mm. Seven of 10 patients had a patella baja, and two of these patients had patellar impingement. One patient needed a proximalisation of the tuberositas. The patellar height in the KJB group averaged 14.6 mm after revision, with only one patient having a patella baja. This new device, adjustable kneespacer for revision TKA ("the KJB"), seems to provide better control of the patellar position in total knee revision.     

Postoperative hyperglycaemia control reduces postoperative complications in patients subject to total knee arthroplasty

Background

The aim of our study was the early detection and treatment of patients with unknown alterations of the hydrocarbon metabolism subject to total knee arthroplasty in order to reduce the incidence of postoperative complications.

牛津双柱单髁置换术与全膝关节置换术治疗膝内侧骨关节炎的近中期疗效对比

目的:探讨牛津双柱单髁置换术(UKA)与全膝关节置换术(TKA)治疗膝内侧骨关节炎的近中期疗效。方法:回顾性队列研究。纳入2016年10月—2019年11月安徽医科大学第四附属医院50例膝关节内侧间室骨关节炎患者的临床资料。其中,采用牛津双柱UKA治疗的25例(25膝)为UKA组,男7例、女18例,年龄54～81岁;采...     

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.        

Computer navigation is a useful intra-operative tool for joint line measurement in total knee arthroplasty

BackgroundRestoration of the native joint line in total knee arthroplasty is important in restoring ligamentous balance and normal knee kinematics. Failure to achieve this could lead suboptimal outcomes. The purpose of this study was to analyze the clinical and functional outcome of patients who demonstrated joint line changes after computer-assisted (CAS) total knee arthroplasty (TKA).MethodsOne hundred sixty-eight patients (168 knees) underwent CAS TKA by two surgeons at a single institution with 2 years follow-up. The final change in joint line was calculated from the verified tibial resection and distal femoral cuts. Group A patients had joint line changes of less than 4 mm and Group B patients had joint line changes of more than 4 mm. Post-operative Oxford scores, Knee scores, Function scores and SF-36 scores were obtained at 6 months and 2 years post TKA.ResultsThere was significant linear correlation between joint line changes and Oxford scores (P = 0.0001), Function scores (P = 0.0001) and Knee scores (P = 0.0001) at 6 months and Oxford scores (P = 0.0001) alone at 2 years with increasing joint line changes having poorer outcome scores. Group A compared to Group B patients demonstrated better Oxford scores (P = 0.0001), Function scores (P = 0.0001), Knee scores (P = 0.0001) and total SF-36 scores (P = 0.003) at 6 months as well as better Oxford scores (P = 0.0001) and Knee scores (P = 0.014) at 2 years.ConclusionsCAS is a useful intra-operative tool for assessing the final joint line in TKA. Outliers in joint line changes of ≥ 4 mm are associated with poorer clinical outcome scores.Level of evidence: Prognostic Study, Level II-1.     

Clinical outcomes and patient satisfaction following revision of failed unicompartmental knee arthroplasty to total knee arthroplasty are as good as a primary total knee arthroplasty

BackgroundWith unicompartmental knee arthroplasty (UKA) being increasingly performed for medial compartment osteoarthritis (OA) of the knee, revision total knee arthroplasty (TKA) for failed UKA is expected to increase. Our primary aim is to evaluate patients in our tertiary institution who underwent revision of failed UKA to TKA to compare their pre-operative clinical scores (patient-reported outcome measures, PROMs) to those of primary TKA.MethodsRetrospective review of our institutional arthroplasty registry between 2001 and 2014 was performed. We identified 70 patients who underwent revision of UKA to TKA. The revision UKA to TKA patients was matched with 140 patients who underwent primary TKA for OA in terms of preoperative demographics, gender, age at time of surgery, body mass index (BMI), primary surgeon, and PROMs. Intra-operative data and postoperative complications or re-revision surgeries performed were reviewed.ResultsIn the revision UKA to TKA group, more stems, augments or constrained implants were used compared to primary TKA. A greater proportion of patients with metal-backed UKA revision to TKA required stems, augments or constrained implants as compared to all-polyethylene UKA revision to TKA, but not a significant proportion (P = 0.250). At two years postoperatively, there were no significant differences observed between the groups in terms of patient satisfaction and PROMs.ConclusionsThis study showed similar outcomes following revision of failed UKA to TKA and primary TKA. There were significant improvements in PROMs for revision UKA to TKA, which is comparable to that of primary TKA.     

Cadaveric results of an accelerometer based, extramedullary navigation system for the tibial resection in total knee arthroplasty

IntroductionIn total knee arthroplasty, the accuracy and precision of the tibial resection must be improved. The purpose of this study was to determine the accuracy and time associated with the use of an accelerometer based, extramedullary surgical navigation system for performing the tibial resection.Materials and methodsFour orthopedic surgeons performed a tibial resection utilizing the KneeAlign? system, each on five separate, cadaveric tibiae. Each surgeon was assigned a preoperative “target” of varus/valgus alignment and posterior slope prior to each resection. The alignment of each resection was measured using both plain radiographs and computed tomography, along with the time required to use the device.ResultsRegarding coronal alignment, the mean absolute difference between the preoperative “target” and tibial resection alignment was 0.77° ± 0.64° using plain radiograph, and 0.68° ± 0.46° using CT scan measurements. Regarding the posterior slope, the mean absolute difference between the preoperative “target” and the tibial resection was 1.06° ± 0.59° using plain radiograph, and 0.70° ± 0.47° using CT scan measurements. The time to use the KneeAlign? for the fifth specimen was less than 300 s for all four orthopedic surgeons in this study.DiscussionThis cadaveric study demonstrates that the KneeAlign? system is able to accurately align the tibial resection in both the coronal and sagittal planes.Level of evidenceCadaveric study.