Experience with computer-assisted navigation for total knee arthroplasty in a community setting

This study analyzed the initial experience with computer-assisted navigation for total knee arthroplasty (TKA) in a community hospital. One hundred TKAs performed with a navigation system were compared with 100 performed conventionally. Component alignment results, measured by computed tomography, were grouped as good, fair, poor, or extremely poor, based on deviation from the surgical goal. More navigated knees were classified as good (sagittal, 78%-93%; coronal, 98%; axial, 78%-85%) compared with conventional (sagittal, 47%-64%; coronal, 91%; axial, 89%-90%). Outliers were reduced both in number and severity with navigation. Additional time required to navigate diminished with experience, although improved component alignment was observed from the initial cases. Navigation resulted in improved alignment, with minimal time cost, and is a useful tool for TKA for the community surgeon.     

The use of navigation in total knee arthroplasty for patients with extra-articular deformity

Computer-assisted navigation for total knee arthroplasty provides high technology instrumentation that may improve the technique for restoring the normal lower limb mechanical axis. This study evaluated the use of computer-assisted navigation in 7 patients (9 total knee arthroplasties) with a radiographic femoral extra-articular deformity. Postoperatively, the mechanical axis deviated medially by a mean of 1.3 degrees +/- 0.9 degrees (range, -0.2 degrees to 2.5 degrees ). Early patient outcomes showed an increase in the average preoperative to postoperative Knee Society Scores (from 62 to 92, P < .05), function scores (from 52 to 83, P < .05), and range of motion (from 4 degrees -74 degrees to 0.6 degrees -98 degrees , P < .05). These results support the use of computer-assisted navigation as effective high technology instrumentation in recreating an acceptable mechanical axis in patients with distorted anatomical landmarks.     

Computer-assisted navigation for cruciate-retaining total knee arthroplasty in patients with advanced valgus arthritic knees

BackgroundThe valgus arthritic knee is a complex deformity involving both soft tissue and bony problems that significantly affect the positioning of the components for, and decrease the accuracy of, reconstructed alignment in total knee arthroplasty (TKA). The unique bony deformity and soft tissue problem makes the use of conventional mechanical instrumentation difficult and leads to unsatisfactory results.PurposeThe purpose of this study was to investigate the effect of computer-assisted navigation for TKA on the postoperative mechanical axis, component alignment, and functional outcomes in the arthritic knee with genu valgus deformity.MethodsFrom January 2003 to August 2009, 24 patients (24 knees) with advanced valgus knee arthritis who underwent computer-assisted navigation for cruciate-retaining TKA were retrospectively reviewed. The accuracy of the postoperative mechanical axis and component alignment, and functional outcomes were assessed.ResultsThe mean postoperative mechanical axis was 180.2° (range, 178.1–182.5°). All patients achieved the targeted goal of a leg axis within 3° of the neutral axis. The joint line was not substantially elevated. No patient required conversion to a constrained component to achieve stability. At a mean follow-up of 45.5 months, the Hospital for Special Surgery (HSS) knee score improved from a mean preoperative score of 55.6 to 92.8 postoperatively. The International Knee Society (IKS) clinical score improved from 42.2 to 95.9. The IKS for pain improved from 15.4 to 47.1, and the IKS knee function score improved from 35.8 to 95.4.ConclusionComputer-assisted navigation for TKA is a useful alternative technique for advanced valgus knee arthritis where accurate restoration of the joint line, proper alignment of the limb and prosthetic components, and meticulous soft tissue balancing may be challenging because of bony deformities and soft tissue contractures.     

Accelerometer-based computer navigation for performing the distal femoral resection in total knee arthroplasty

The use of intramedullary alignment guides for performing the distal femoral resection in total knee arthroplasty (TKA) have not been shown to be highly accurate. Forty-eight knees underwent a TKA using a portable, accelerometer-based surgical navigation system for performing the distal femoral resection (KneeAlign 2 system; OrthAlign, Inc, Aliso Viejo, Calif). Of the femoral components, 95.8% were placed within 90° ± 2° to the femoral mechanical axis in the coronal plane, and 93.8% of the TKAs had an overall lower extremity alignment within 3° of neutral to the mechanical axis, based on postoperative, standing, hip-to-ankle radiographs. The KneeAlign 2 is highly accurate in positioning the femoral component in TKA, and accelerometer-based navigation is able to reliably determine the hip center of rotation and femoral mechanical axis.     

Periprosthetic femoral supracondylar fracture after total knee arthroplasty with navigation system

We report 1 patient with a supracondylar periprosthetic fracture 1 month after computer-assisted total knee arthroplasty. The fracture line extended from previous anchoring pinholes into the supracondyle area. Intramedullary nailing of the left femur was performed under close reduction. The possible complication of pinhole fracture to total knee arthroplasty with navigation system should be kept in mind.     

全膝关节表面置换治疗严重膝关节畸形

目的探讨人工全膝关节表面置换术(TKA)治疗严重膝关节畸形临床疗效。方法应用全膝关节表面置换治疗严重膝关节畸形36例(48膝)。使用HSS评分标准评估分析术前、术后膝关节功能及术后疼痛、膝关节活动度的改善情况。43膝采用后稳定型人工全膝关节假体,5膝采用CCK型人工全膝关节假体。结果术后早期均无感染等并发症发生。术后X线片示假体位置良好,下肢力线良好。患者均获得随访,时间6～18个月。HSS评分术前为(41±5.3)分,术后6个月为(87.7±6.5)分。手术优良率为83.3%。患者疼痛、功能方面及活动度均有明显改善。结论全膝关节置换术对严重膝关节畸形的治疗效果满意。但应严格掌握手术适应证。     

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

Tibial intramedullary or extramedullary alignment guides have not been shown to be highly accurate in performing the tibial resection in total knee arthroplasty (TKA). Since May 2010, a total of 42 knees underwent a TKA using a hand-held, accelerometer-based surgical navigation system for performing the tibial resection (KneeAlign; OrthAlign Inc, Aliso Viejo, Calif). Postoperative standing anteroposterior hip-to-ankle and lateral knee-to-ankle radiographs demonstrated that 97.6% of the tibial components were placed within 90° ± 2° to the mechanical axis in the coronal plane, and 96.2% of the components were placed within 3° ± 2° to the mechanical axis in the sagittal plane. The KneeAlign greatly improves the accuracy of tibial component alignment in TKA.     

Comparison of computer-assisted navigation and conventional instrumentation for bilateral total knee arthroplasty

This prospective study analyzed computer-assisted surgery (CAS) navigation and conventional instrumentation in bilateral total knee arthroplasty. Sixty patients underwent CAS navigation in 1 knee and conventional instrumentation in the contralateral knee randomly. The target zone resided in the reconstructed mechanical axis within a range of 3 degrees varus or valgus. The reconstructed mechanical axes in the CAS navigation group were significantly closer to planned axes than those in the conventional group. Average blood loss in the CAS navigation group was lower, whereas mean tourniquet time was longer than in the conventional group. No surgery-related complications existed in either group. The results indicate that, despite longer operative time, CAS navigation total knee arthroplasty is a safe procedure and outperforms conventional technique in accuracy of leg axes.     

全膝关节置换治疗严重膝内翻伴屈曲畸形的疗效分析

目的：分析全膝关节置换（TKA）治疗严重膝内翻伴屈曲畸形的疗效。方法对2005年1月至2010年10月在本院行 TKA 治疗的25例（36膝）严重膝内翻伴屈曲挛缩畸形患者的临床资料进行回顾性分析,其中男7例,女18例,平均70．5岁（55～80岁）。原发疾病为骨性关节炎22例,类风湿性关节炎3例。术前术后均采用 HSS 膝关节评分系统评分,评价 TKA 的临床疗效。结果25例36膝均获得随访,平均术后随访6年（4～9年）。屈曲挛缩度由术前的（21±63）°减小到（1．1±2．3）°;内翻畸形由术前（35±4．8）°减小到（3±2．1）°;膝关节的活动度由术前（70．5±20．5）°增加到（115．1±5．3）°;膝评分平均为由（33．2±10．5）分提高到（90．7±8．5）分,功能评分平均为（35．5±14．2）分提高到（85．6±10．5）分,其中优21例（28膝）,良2例（3膝）,一般2例（3膝）;优良率为86％。多数病例术后膝关节力线正常,2例残留5°～10°的内翻畸形。结论全膝关节置换治疗严重膝内翻伴屈曲畸形能获得较好的临床效果。     

全膝关节置换术治疗严重膝外翻的疗效观察

目的探讨全膝关节置换术治疗严重膝关节外翻畸形的临床疗效。方法对严重膝外翻患者39例(43膝)采用髌旁内侧入路、常规截骨、选择性的外侧软组织松解、安装后稳定型假体或半限制型假体进行全膝关节置换术。手术前后测量股胫角(FTA)、检查膝关节活动度并行KSS评分。结果所有患者均获得随访,时间6~22个月。FTA由术前的17°~38°(26.3°±2.3°)降低至1°~7°(4.2°±1.6°),P0.05;膝关节活动度由术前的62°~91°(63.7°±4.1°)提高到102°~120°(106.9°±5.1°),P0.05;KSS评分由术前的17~39(23.8±2.5)分提高到83~97(88.6±4.1)分,P0.05。结论采用髌旁内侧入路、常规截骨、选择性的外侧软组织松解、安装后稳定型假体或半限制型假体实施人工全膝关节置换术治疗严重膝外翻畸形的患者,可获得良好的临床效果,患者膝关节功能得到明显改善,生活质量显著提高。     

伴有关节外畸形的膝骨关节炎行全膝关节置换术的治疗体会

背景：伴有关节外畸形的膝骨关节炎临床上并不常见,手术治疗难度较大,目前术式选择关节内代偿性截骨还是关节外截骨矫形后再行膝关节置换术尚存争议。目的：探讨伴有关节外畸形的膝骨关节炎行全膝关节置换术（TKA）的方法、适应证和疗效。方法：2001年4月至2007年2月行关节外截骨的TKA或关节内截骨的TKA治疗膝骨关节炎合并关节外畸形患者8例,男1例,女7例;年龄39~72岁,平均63.9岁。7例股骨畸形由骨折畸形愈合造成,1例胫骨畸形伴弓形股骨为代谢性骨病所致。结果：全部获得随访,随访时间为7~13年,平均11年。HSS评分从术前11~48分,平均34.5分,提高至术后76~94分,平均87.0分。下肢机械轴线由术前平均内翻偏移14.6°改善至术后平均内翻偏移2.1°。未见感染,骨延迟愈合、不愈合,血栓栓塞等并发症,中远期疗效良好。结论：伴有股骨关节外畸形的膝骨关节炎治疗难度较大,采用关节外截骨结合一期或二期TKA可有效恢复下肢机械轴线,获得满意的临床效果;如果关节内截骨的TKA使用传统手术器械,术后下肢机械轴线可能恢复不良。     

Computer-assisted fluoroscopic navigation system for removal of distal femoral bone cement in revision total hip arthroplasty

Removal of the femoral bone cement in revision total hip arthroplasty with a high-powered drill or burr potentially has a risk of damage to the bone, resulting in perforation and fracture of the femur. Recently, we have used a computer-assisted fluoroscopic navigation system for the revision of cemented total hip arthroplasty with a high-powered burr and completely removed the distal femoral bone cement with no complications in 6 cases. Thus, a computer-assisted fluoroscopic navigation system is a useful tool for the improvement of the surgical technique in revision total hip arthroplasty.     

全膝关节置换治疗严重膝外翻畸形的临床研究

[目的]探讨全膝关节置换术治疗严重膝外翻畸形的临床疗效和手术方法.[方法]2008年6月～2010年3月,15例(18膝)严重膝外翻患者,术前X线测量FTA角,检查膝关节活动度,并且使用美国膝关节协会评价标准KSS评分及功能评分.手术方法采用髌旁外侧入路、针对性截骨、选择性的外侧软组织松解、安装限制性小的假体或非限制型假体进行全膝关节置换术.术后测量FTA角,术后定期随访检查膝关节活动度并行KSS评分及功能评分,评价手术效果.[结果]所有患者均获得随访,随访时间8～28个月.FTA角由术前的27.0°(20°～35°)降低至4.5°(0°～9°);膝关节活动度由术前的79.4°(70°～90°)提高到109.7°(100°～120°);KSS评分由术前的28.9分(15～40分)提高到88.7分(85～95分),功能评分由术前的23.0分(0～40分)提高到89.1分(85～95分);差异均有非常显著性意义(P<0.01).[结论]所有患者行全膝关节置换术后外翻畸形基本得到纠正,所有病例术后无明显疼痛,行走及上下楼梯等功能较术前明显改善.说明对于严重膝外翻畸形的患者,采用髌旁外侧入路、针对性截骨、选择性的外侧软组织松解、安装限制性小的假体或非限制型假体实施人工全膝关节置换术治疗,可以取得满意的临床效果,从而明显改善患者膝关节的功能,提高患者的生活质量.     

Alignment of computer-assisted total knee arthroplasty in patients with altered hip center

This study aimed to determine limb and component alignment after computer-assisted total knee arthroplasty in 30 patients (32 limbs) with an altered hip center due to a prior hip implant or deformed femoral head. There were no outliers greater than ±3° in the postoperative coronal alignment of the limb and the femoral component in relation to the altered hip center. Two limbs (8%) were more than ±3° for coronal alignment of the femoral component in relation to the anatomical hip center and 96% of limbs had less than 2° deviation in relation to the altered hip center. Computer-navigated total knee arthroplasty results in accurate restoration of lower limb and component alignment in patients with prior hip implants or deformed femoral heads where accurate restoration of alignment may be challenging due to altered hip center.     

计算机导航全膝关节置换术在创伤后股骨干严重畸形患者中的应用

目的介绍计算机导航辅助全膝关节置换术（TKA）在伴有关节外股骨严重畸形患者中的应用.方法 回顾分析了在2005年1月至2010年为5月间,我院共收治了伴有股骨严重畸形的单侧膝关节骨性关节炎患者6例,在计算机导航辅助下进行了人工全膝关节置换术.结果平均随访27个月.术前膝评分平均10分,膝功能评分平均22分.术后膝评分平均85分,膝功能评分72分.术后下肢力线偏差均在3°以内.无患者出现导航相关并发症.结论对于伴有严重关节外畸形的患者,计算机导航全膝关节置换术不需要进行股骨、胫骨截骨,手术创伤相对较小,术后患者恢复快.对此类患者计算机导航全膝关节置换术具有良好的适应证.     

Comparison of limb and component alignment using computer-assisted navigation versus image intensifier-guided conventional total knee arthroplasty: a prospective, randomized, single-surgeon study of 467 knees

Total knee arthroplasty was performed in 282 knees with image-free navigation (group A) and in 185 with optimized conventional technique (group B). Mean postoperative mechanical axis of the limb was 179.7 degrees in group A and 179.1 degrees in group B (P < .002). There was a higher percentage of knees in group A that had restoration of mechanical axis to +/-1 degrees, +/-2 degrees, and +/-3 degrees of neutral (P < .0001). There were 9.2% outliers (+/-3 degrees) in group A and 21.6% outliers in group B (P < .0001). For knees exceeding 20 degrees varus, there was no significant difference between the mean mechanical axes in the 2 groups. Both components were aligned within 3 degrees of neutral in 90.8% of the knees in group A and 76.2% of the knees in group B (P < .0001).     

人工全膝关节置换术中联合股骨外髁滑移截骨术矫正股骨外弓畸形的疗效分析

目的探讨人工全膝关节置换术(total knee arthroplasty,TKA)中采用股骨外髁滑移截骨术(lateral condyle sliding osteotomy,LCSO)矫正股骨外弓畸形的疗效。方法回顾分析2018年7月—2020年7月TKA中采用LCSO治疗的17例伴股骨外弓畸形的骨关节炎患者临床资料。男3例,女14例;年龄58~68岁,平均63.2岁。股骨外弓畸形病因:股骨发育畸形12例,股骨骨折畸形愈合5例。膝关节骨关节炎KellgrenLawrence分级:Ⅲ级4例,Ⅳ级13例。术前生理外翻角为9.5°~12.5°,平均10.94°。病程3~25年,平均15.1年。术前及末次随访时测量股骨远端机械外侧角(mechanical lateral distal femur angle,mLDFA)、髋-膝-踝角(hip-knee-ankle angle,HKA)、机械轴偏向(mechanical axis deviation,MAD),评估关节外畸形在关节内矫正及下肢机械力线恢复情况;采用膝关节学会评分系统(KSS)膝评分和功能评分、疼痛视觉模拟评分(VAS)、膝关节活动度(range of motion,ROM)评估疗效;行膝内、外翻应力试验,X线片复查截骨片愈合情况,评估关节稳定性及LCSO的安全性。结果术后患者切口均Ⅰ期愈合,无切口感染、下肢深静脉血栓形成等术后早期并发症发生。17例患者均获随访,随访时间12~36个月,平均23.9个月。截骨片均达骨性愈合,愈合时间2~5个月,平均3.1个月。术后膝内、外翻应力试验均为阴性,未发生外侧副韧带松弛、断裂,膝关节不稳,假体松动、翻修、感染等情况。末次随访时mLDFA、HKA、MAD及膝关节ROM、VAS评分、KSS膝评分和功能评分均较术前显著改善,差异有统计学意义(P<0.05)。结论在伴有股骨外弓畸形TKA中应用LCSO疗效确切且安全,关节外畸形在关节内矫正,一次手术可同时恢复下肢机械力线和关节平衡。     

Three-dimensional analysis of computed tomography-based navigation system for total knee arthroplasty: the accuracy of computed tomography-based navigation system

We evaluated the postoperative alignment of 37 primary total knee arthroplasties performed using a computed tomography–based navigation system (Vector Vision Knee 1.5; Brain Lab, Germany) with a new 3-dimensional analysis. The mean coronal femoral angle was 89.0° ± 1.4° (85.5°-92.8°), and the coronal tibial component was 89.2° ± 1.0° (87.4°-91.6°). The hip-knee-ankle angle was observed to be 178.2° ± 1.5° (173.9°-181.8°). The external rotational alignment of the femoral component relative to the surgical epicondylar axis was −0.5° ± 1.7° (−3.2° to 3.4°). The results demonstrated that a computed tomography–based navigation system provided a reasonably satisfactory component alignment. The discrepancy between the 2-dimensional and 3-dimensional evaluations was 1.0° ± 0.9° (0.1°-3.4°). Three-dimensional analysis is necessary to evaluate the accuracy of the navigation system.     

Intraoperative passive knee kinematics during total knee arthroplasty surgery

Surgical navigation systems for total knee arthroplasty (TKA) surgery are capable of capturing passive three‐dimensional (3D) angular joint movement patterns intraoperatively. Improved understanding of patient‐specific knee kinematic changes between pre and post‐implant states and their relationship with post‐operative function may be important in optimizing TKA outcomes. However, a comprehensive characterization of the variability among patients has yet to be investigated. The objective of this study was to characterize the variability within frontal plane joint movement patterns intraoperatively during a passive knee flexion exercise. Three hundred and forty patients with severe knee osteoarthritis (OA) received a primary TKA using a navigation system. Passive kinematics were captured prior to (pre‐implant), and after prosthesis insertion (post‐implant). Principal component analysis (PCA) was used to capture characteristic patterns of knee angle kinematics among patients, to identify potential patient subgroups based on these patterns, and to examine the subgroup‐specific changes in these patterns between pre‐ and post‐implant states. The first four extracted patterns explained 99.9% of the diversity within the frontal plane angle patterns among the patients. Post‐implant, the magnitude of the frontal plane angle shifted toward a neutral mechanical axis in all phenotypes, yet subtle pattern (shape of curvature) features of the pre‐implant state persisted. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1611–1619, 2015.     

全膝关节表面置换术治疗膝骨性关节炎

目的分析人工全膝表面置换治疗膝骨性关节炎的临床效果。方法对21例29膝的膝骨性关节炎病例行人工膝关节置换术,单膝关节置换13例,双膝关节置换8例,全部采用后方稳定性假体。结果随访6~47个月,平均22.6个月,采用HSS评分系统进行分析,优15例,良5例,可1例。患者术后在疼痛、功能方面都有明显改善。结论全膝关节表面置换术对治疗严重膝骨性关节炎效果满意。术中精确的截骨操作、正确的软组织松解及术后指导康复是手术治疗成功的关键。