Computerised and technical navigation in total knee-arthroplasty

Abstract The objective of the study was to evaluate the precision, concordance, practicability and the early clinical outcome of the use of a computerised navigation system in a comparative study with a group of 100 patients. Two groups of 50 patients each underwent implantation of a bicondylar knee prosthesis either by means of the freehand navigation system or by means of technical instrumentation. We found that the computerised navigation system provided a higher precision than the technically instrumented implantation: 94% of the prostheses implanted with the navigation system have an alignment within a range of -3° to 3° on of the Mikulicz line. Only 46% of the patients operated by means of the technical instrumentation reached this aspired result. Furthermore, the navigation system showed smaller ranges in the deviation of the aspired alignment. The radiological and computer-modeled alignment values differed both pre- and postoperatively, but to a larger extent before surgery. The varus or valgus deviations of the axis were more distinct radiologically under the weight of the patient’s body than in the computer model. The clinical outcome examined by the use of the HSS score after a mean followup of 7 months is good in both groups, and without significant differences. On average, the duration of surgery was 13 minutes longer in the computerised navigation group. We conclude that the benefit of the computerised navigation system is represented by the high improvement of precision. Achieving early clinical results identical to those in the technical instrumentation group, we expect a reduction of aseptic loosening in the computerised navigation group.     

微创与切开复位接骨板内固定治疗膝关节内骨折的比较

[目的]比较研究微创接骨板内固定和切开复位接骨板内固定对膝关节内骨折的治疗效果,探讨生物学内固定在膝关节内骨折中的使用价值.[方法]总结近年来根据生物学固定原则,以微创接骨板固定术(MIPO)治疗的膝关节内骨折共21例.以创伤类型及年龄等因素进行配对,选择切开复位内固定(ORIF)治疗的病例资料比较手术及术后恢复情况.采用HSS评分评价结果.[结果]MIPO组随访10～16个月(平均14.2个月),有2例进行骨移植术,平均手术时间60.0 min,术中失血量45.0 ml,平均骨折愈合时间10.0周,3例有5°以上膝内、外翻畸形,HSS功能评分平均86.67分;ORIF组经过12～48个月(平均21.2个月)随访,有18例进行骨移植术,平均手术时间79.52 min,平均术中失血量117.1 ml,平均骨折愈合时间12.24周,2例发生5°以上膝关节内、外翻畸形,HSS功能评分平均82.14分.两组均获得骨愈合,没有感染和内固定断裂等并发症发生.比较发现两组患者在手术时间、术中失血量、骨折愈合时间和功能恢复方面差异有统计学意义.[结论]对于合适的膝关节内骨折病例以微创接骨板内固定治疗可以降低植骨需求和术中失血,在手术过程和术后恢复方面有明显优势.     

The patella and tibial condyle position after combined and after closing wedge high tibial osteotomy

High tibial osteotomy changes the patella and tibial condyle position, which makes the subsequent total knee replacement technically demanding. From 1 January 1993 to 31 December 2000, combined osteotomy [After the first osteotomy made 2 cm distally to the joint line, a bone wedge is removed based laterally. Its tip ends at the center of the tibial condyle (half bone wedge). The distal part of the tibia is placed into the valgus position and the half bone wedge is placed into the gap opened medially.] was performed on 103 knees and closing wedge osteotomy was performed on 47 consecutive knees. Eighty combined (group A) and 41 closing wedge (group B) osteotomy were studied. All knees were assessed radiologically before surgery, in the 10th postoperative week, in the 12th postoperative month and at the time of the final follow-up (in group A—66.15 months, in group B—66.61 months). We examined the change of the femorotibial angle, of the patellar height according to the method of Insall and Salvati, of the tibial slope angle according to the method of Bonnin, of the tibial condylar offset according to the method of Yoshida and of the distance between the lateral tibial plateau and the top of the fibular head. In group A and B, the recurrence of the varus deformity was not noted and valgus alignment did not increase in any case. In group-A, the Insall–Salvati ratio remained unchanged in 65% of knees. The tibial slope angle decreased in both groups. There was correlation between the change of the tibial condylar offset and the angle of the correction in both groups. There was correlation between the change of the distance between the lateral tibial plateau and the top of the fibular head. After combined osteotomy, the transposition of the tibial condyle and the decrease of the distance between the lateral tibial plateau and the top of the fibular head was less than after closing wedge osteotomy, although the average angle of correction was more after combined osteotomy (11.835°), than after closing wedge osteotomy (9.465°). Theoretically, the recurrence of the varus deformity, the increase of the valgus alignment and (in majority of cases) the shortening of the patellar tendon do not compromise the likelihood of successful conversion to the subsequent total knee replacement, either after combined or after closing wedge osteotomy. The combined osteotomy does not lead to considerable transposition of the tibial condyle and to considerable lateral tibial bone loss; therefore, theoretically, the combined osteotomy does not impair the subsequent total knee replacement.     

Surgical treatment of multiple knee ligament injuries in 44 patients: 2–8 years follow-up results

The purpose of the study was to evaluate the mid-term results of surgical treatment in different groups of patients with multiple knee ligament injuries. Review of our patients’ records revealed that 48 acute and chronic patients were surgically treated for combined knee injury. Due to severe capsular damage in these injuries, open techniques were used. In our treatment protocol, avulsed ligaments and tears of the posterolateral and posteromedial corner were repaired if possible, whereas midsubstance tears of cruciate ligaments and chronic cases were reconstructed with autografts. Postoperatively, an accelerated program of rehabilitation was introduced, aiming to progressively mobilize the joint and improve muscle endurance. For the follow-up evaluation we designed a protocol composed of two parts. In the first part, anatomical lesions were recorded and in the second part, clinical evaluation was performed using the Lysholm score, the Tegner rating system, the IKDC evaluation form, and the KT1000. Student’s t tests and chi-square tests were used for data analysis. Forty-eight patients (mean age 28.6±11.9 years; 41 males) were classified according to the specific anatomical structures involved. Group A included 12 anterior cruciate ligament (ACL) and medial structure injuries, group B included 11 ACL or posterior cruciate ligament (PCL) ruptures combined with posterolateral injuries, and group C consisted of 25 knee dislocations (ACL and PCL ruptures which might be combined with damage of the collateral ligaments). Thirty-eight patients were surgically treated during the acute phase and ten patients were treated chronically. Forty-four patients (91.6%) were followed up at a mean of 51.3±29.9 months. Average Lysholm score was 87±12.3; average Tegner score was 5.09±2.19 before accident and 4.34±2.12 in re-examination; IKDC score was A in 10 cases, B in 22, C in 6, and D in 6. The mean range of motion was 129.9°±12.5°. The average loss of extension and flexion were 1.6°±2.5° and 7.6°±7.9°, respectively. The side-to-side difference in corrected anterior and posterior translation in quadriceps neutral angle and in anterior translation in 30° angle was <3 mm for about 65% of our patients. Surgical treatment of multiple knee ligament injuries, using autografts, provided satisfactory stability, range of motion, and subjective functional results. However, despite the improvement of the quality of life, the preinjury patients’ activity level was not fully obtained in re-examination. Patients underwent surgical treatment during the acute phase had better scores in several points, but finally there was no statistical significance between acute and chronic patients. Moreover, no statistically significant differences were observed among the groups with specific damaged anatomical structures.     

计算机导航辅助下人工全膝关节置换术

目的通过分析计算机导航辅助下人工全膝关节置换术中定位与软组织平衡的辅助检测作用,与传统手术进行疗效差异的比较,探讨计算机导航辅助手术的安全性、可靠性及其优势与不足。方法自2004年10月至2005年10月行计算机辅助人工全膝关节置换术18例22膝(导航组),男7例8膝,女11例14膝;年龄35～74岁,平均67岁。导航组采用计算机辅助下行人工全膝关节置换手术。从2003年10月至2004年10月用传统手术的52例中随机抽取17例22膝(非导航组),男5例6膝,女12例16膝;年龄56～78岁,平均65岁。非导航组采用髓内定位杆(股骨)、髓外定位杆(胫骨)定位,常规手术行人工全膝关节置换。全部44膝均为初次置换,两组患者的原始疾病、年龄、HSS评分行配对t检验,差异无统计学意义(P>0.05)。对比两组术前、术后的力线、软组织平衡、并发症、出血量、手术时间及随访情况,进行统计学处理。结果全部病例随访3～12个月,平均10个月。导航组力线误差大多在2°～3°,非导航组3°～6°。软组织平衡角度变量导航组大多在2°以内,非导航组2°～4°;软组织平衡分离变量导航组大多在2～4mm,非导航组5～7mm。导航组出血量大多在550～700ml,非导航组700～900ml;导航组手术时间大多在75～100min,非导航组45～60min。经SPSS10.0统计软件处理,两组在术后力线、软组织平衡角度变量和分离变量、出血量、手术时间,其差异均有统计学意义(P<0.05)。结论计算机导航辅助人工全膝关节置换术,使假体的植入位置更为准确,术后下肢力线和软组织平衡更佳,并能减少出血量,早期疗效满意,但延长了手术时间。     

跖跗关节骨折脱位手术治疗21例报告

我院自 1993年 5月 - 2 0 0 1年 5月采用闭合复位或切开复位克氏针内固定治疗跖跗关节骨折脱位2 1例 ,取得满意疗效 ,现报告如下。1　临床资料　　本组 2 1例 ;男 14例 ,女 7例 ;左侧 12例 ,右侧 8例 ,双侧 1例 ;年龄 2 1～ 6 8岁 ,平均 4 0 5岁 ;闭合性骨折脱位 16例 ,开放性骨折脱位 5例 ;按照Kuss分类法 :同向性脱位 15例 ,分离性脱位 6例 ;伤因 :车祸伤 12例 ,高处坠落伤 5例 ,重物压伤 3例 ,扭伤 1例。同时伴肢体骨折 6例 ,胸腹伤 3例。2　治疗方法本组 16例闭合性损伤均采用闭合复位克氏针内固定。一般在硬麻下进行 ,取平卧位 ,膝关…     

螺旋CT多功能重建在骨关节外伤中的应用

目的 探讨螺旋cT功能重建在骨与关节外伤中的应用，提高重建技术的使用能力和诊断水平。方法 对使用双层螺旋CT，SSD，MPR，MIP等多种方式重建检查的49例复杂的骨与关节外伤病例进行回顾性分析。结果 49例骨关节外伤重建成像，其中，颅底3例，颌面部7例，颈、胸、腰、骶椎共17例，肩胛骨3例，髋关节8例，膝关节11例。SSD在显示碎骨片明显移位的空间关系方面较MIP，MPR为佳，它可以直观地、立体地、清晰地、多角度显示骨关节损伤，而MIP在显示骨折细节方面较优，尤其在外伤中颅窝观察有关神经孔方面。结论 螺旋CT的SSD，MPR和MIP技术的综合应用，对复杂的骨折、关节损伤的显示效果良好，具有较高的临床应用价值。     

特异性COX-2抑制剂保护骨关节炎软骨的临床观察

目的探讨特异性COX-2抑制剂对骨关节炎的关节软骨保护作用的临床研究。方法门诊选取膝关节骨关节炎患者80例,随机分为特异性COX-2抑制剂组和维骨力对照组,各40例,单盲给药。应用平均Womac关节炎指数评分和平均OA严重程度指数评定两组用药前后临床症状改善情况及使用血清软骨代谢标志物蛋白聚糖与型胶原和关节MRI进行检测关节软骨结构与功能的改变情况,并作统计学分析。结果经12个月治疗观察,特异性COX-2抑制剂组的平均Womac关节炎指数评分和平均OA严重程度指数在前3个月改善明显优于维骨力对照组(P<0.01),但在治疗12个月后,两组差异不显著(P>0.05);治疗12个月后特异性COX-2抑制剂组的软骨代谢指标蛋白聚糖和型胶原及关节MRI均显示组内变化显著(P<0.01),而与维骨力组对比结果无显著性差异(P>0.05)。结论特异性COX-2抑制剂对骨关节炎的软骨有保护和促进修复作用,兼有抗炎与保护软骨双重疗效,它是一类既能改善关节炎症状又能改善关节软骨结构的药物,值得临床广泛应用。同时本研究为其在临床应用和进一步研究此类药物提供了更好的理论基础和依据。     

Measurement of upper extremity orientation by video stereometry system

In the attempt to gain a broader understanding of the causal relationships behind work-related symptoms of pain in the human shoulder, monitoring of arm position is crucial. Different methods have been used with varying accuracy. A video-based stereometry system, using infra-red light and reflecting markers for motion analysis, has been introduced for measurements in the fields of ergonomics, biomechanics and sports medicine. The purpose of this study is to investigate the sources of error in using this system for posture registration of the upper limb. Measurements are performed on a calibration fixture, on a mechanical model of the upper limb and on a subject with an exoskeleton. Particular, attention is given to inconsistencies and relative errors due to the finite geometrical precision with which the markers are positioned in the calibration fixture and on the studied objects, the limited capability to align the objects relative to the coordinate system of the calibration fixture and the errors connected to angular measurements using protractors etc. It is concluded that the system makes a valuable addition to existing instruments for non-contact posture measurement, and produces position data with an adequate accuracy in normal handling.