High-flex posterior cruciate-retaining vs posterior cruciate-substituting designs in simultaneous bilateral total knee arthroplasty: a prospective, randomized study

The superiority between the posterior cruciate-retaining and the posterior cruciate-substituting designs still remains controversial. We performed a prospective, randomized control study for evaluation of the superiority of these designs. This study investigated 58 knees in 29 patients with simultaneous bilateral total knee arthroplasty, in which the high-flex CR design was randomly implanted in one knee and the high-flex PS design was implanted in the other knee. The follow-up duration averaged 5.0 years, with a minimum duration of 3 years. Postoperatively, Knee Score and pain points in Knee Score resulted in no significant differences between the 2 designs. However, postoperative arc of range of motion, patient satisfaction, and posterior knee pain at passive flexion in the PS design were significantly superior to that of the CR design.     

The effect of preoperative knee deformity on the initial results of cruciate-retaining total knee arthroplasty

Between November 1985 and June 1987, 751 posterior cruciate-sparing total knee arthroplasties were performed on 523 patients who exhibited fixed varus or valgus deformities. Patients excluded from this study included the following: those with a postoperative follow-up period of less than 2 years (including patients who had died), patients who became infected, and patients with previous failed total knee arthroplasty in the same knee. A total of 473 knees left for evaluation. All arthroplasties were measured using anatomic axis for alignment measurement. The Hospital for Special Surgery scoring system was used to determine the clinical scores prior to the end of each follow-up examination. All ligament releases were performed sequentially, including balancing of the posterior cruciate ligament. All arthroplasties were divided into six separate groups depending upon the degree of varus or valgus deformity. Kaplan-Meier curves were constructed using three methods of failure definition. Curves were then compared between groups. The mean Hospital for Special Surgery score was no different between any of the groups, except for the group of 6 degrees-10 degrees varus, which was significantly higher than the mean score of the 11 degrees and higher valgus group. All other groups were the same statistically. It is concluded that severe varus and valgus deformities may be satisfactorily corrected with the use of a cruciate-retaining type of total knee arthroplasty.     

A recession of posterior cruciate ligament in posterior cruciate-retaining total knee arthrosplasty

The range of motion, the stability of the knee, and the prevalence of radiolucent lines in 68 posterior cruciate-retaining (CR) total knee arthroplasties (TKAs) with a retained, but balanced, posterior cruciate ligament were compared with those in 68 knees with a posterior cruciate-substituting (PS) TKAs in the 60 patients who were managed with simultaneous bilateral TKAs. The average range of motion in both groups (126 degrees vs 129 degrees) at the latest follow-up was not significantly different (P = .359). No significant difference in the sagittal laxity of the knee was seen between 2 groups. The prevalence of radiolucent lines was 7% in the CR TKA with a recession posterior cruciate ligament and 12% in the PS TKA group (P = .108). We feel that posterior stabilization is unnecessary in the PS flex knees.     

保留后交叉与不保留后交叉韧带人工膝关节置换术术后效果的Meta分析

目的对人工膝关节置换术保留后交叉韧带与不保留后交叉韧带术后效进行评价。方法按照Cochrane系统评价的方法,计算机检索下列数据库：Medline（1995／2012435）、Pubmed（1995／2012435）、SPINGER（1995／2012435）、JohnWiley（1995／2012435）、ScienceDirect（1995／2012-05）、EBSCO（1995／2012435）、CNKI（1995／2012435）、万方数数据库（1995／2012435）,并采用手工检索等方法收集会议文献。收集所有相关随机对照试验,采用Cochrane协作网提供的软件Revman4．2进行Meta分析。结果经过筛选,共纳入5个临床随机对照实验共685个患者。Meta分析结果显示两组患者术后疼痛评分均降低,但保留后交叉组比不保留后交叉组下降更明显[RR=-1．07,95％a为（-1．86,-0．29）,P〈0．01]。两组患者术后功能评分较术前明显增高,但是保留后交叉组与不保留后叉组术后无统计学差异[RR=-3．34,95％CI为（-7．18,0．50）,P〉0．05]。两组患者术后SF生理评分无统计学差异[RR=-1．26,95％CI为（-3．72,1．21）,P〉0．05]。两组患者术后SF心理评分无统计学差异[RR=-1．53,95％CI为（-3．88,0．83）,P〉0．05]。两组患者术后关节僵硬发生率比较无统计学差异[RR=3．08,95％C／为（0．81,11．65）,P〉0．05]。两组患者术后并发症发生率比较无统计学差异[RR=0．77,95％CI为（0．26,2．35）,P〉0．05]。结论保留后交叉较不保留后交叉韧带人工膝关节置换术更能减轻疼痛评分、而两者术后膝关节功能评分、SF心理评分、SF生理评分、术后并发症都无明显差异。     

In vivo kinematics and kinetics of a bi‐cruciate substituting total knee arthroplasty: A combined fluoroscopic and gait analysis study

After total knee arthroplasty, changes in articular surface geometry, soft tissue treatment, and component alignment can alter normal lower limb function. The guided motion bi‐cruciate substituting prosthesis was designed specifically to restore physiological knee joint motion. We determined whether this design could in vivo normal kinematics and kinetics, not only at the replaced knee, but also throughout both lower limbs. Sixteen patients (4 male, 12 female, mean age of 68.2 years with a range from 58 to 79 years) with primary knee osteoarthritis were implanted with the bi‐cruciate substituting prosthesis. At 6‐month follow‐up, knee joint kinematics was assessed by video‐fluoroscopy during stair‐climbing, chair‐rising/sitting, and step‐up/down. Lower limb overall function was also assessed on the same day by standard gait analysis with simultaneous electromyography during level walking. By video‐fluoroscopy, mean anteroposterior translations between femoral and tibial components during the three motor tasks were 9.7 ± 3.0, 10 ± 2.6, and 6.9 ± 3.5 mm on the medial compartment, and 14.3 ± 3.5, 18.5 ± 3.0, and 13.9 ± 3.8 mm on the lateral compartment, respectively. Axial rotation ranged from 5.6° to 26.2°. Gait analysis revealed restoration of nearly normal walking patterns in most patients. This rare combination of measurements, i.e., accurate rotation‐translation at the replaced knee and complete locomotion patterns at both lower limb joints, suggested that bi‐cruciate substituting arthroplasty can restore physiological knee motion and normal overall function. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1569–1575, 2009     

In vivo kinematic analysis of cruciate-retaining total knee arthroplasty during weight-bearing and non-weight-bearing deep knee bending

The purpose of the present study was to evaluate the in vivo kinematics of the posterior cruciate ligament-retaining total knee arthroplasty during weight-bearing and non-weight-bearing deep knee bending and compare these 2 different conditions. We evaluated the in vivo kinematics of the knee using fluoroscopy and femorotibial translation relative to the tibia tray by 2-dimensional/3-dimensional registration. In the weight-bearing state, the femoral component showed central pivot and bicondylar posterior rollback pattern. During non-weight-bearing, the movement anteriorly occurred on both the medial and lateral side during early flexion, whereas bicondylar femoral component rollback occurred after that. During non-weight-bearing, both the medial and lateral condyle significantly moved anteriorly compared with the weight-bearing state during early flexion. However, bicondylar femoral rollback occurred under both these conditions.     

Gait analysis after total knee arthroplasty. Comparison of posterior cruciate retention and substitution

The objective of this study was to measure three-dimensional knee motion during gait in patients with total knee replacements which either retained the posterior cruciate ligament (n = 11), or required sacrifice of the posterior cruciate ligament and replacement of its function with a posterior stabilizing articular surface (n = 9). Clinically meaningful translations (anterior and posterior, medial and lateral, proximal and distal) and rotations (flexion and extension, internal and external rotation, abduction and adduction) were measured using an instrumented spatial linkage. Although patients from both groups were able to achieve passive full extension and a minimum of 95° flexion, some of their translations and rotations during free speed walking were consistently less than those in a group of healthy controls. Motion during the swing phase of gait was similar for both knee replacement groups. However, abduction and adduction and proximal and distal translation were larger (but neither difference was significant) for the patients with implants with a posterior stabilizing surface, which suggests that the stabilizing surface may not reliably provide as much stability in these directions as does retention of the posterior cruciate ligament. Received for publication on Aug. 28, 1997; accepted on June 10, 1998     

Intraoperative soft tissue balance reflects minimum 5-year midterm outcomes in cruciate-retaining and posterior-stabilized total knee arthroplasty

With the use of an offset type tensor for total knee arthroplasties (TKAs), intraoperative soft tissue balance including the joint component gap and ligament balance was measured in 41 varus-type osteoarthritic patients (19 cruciate-retaining [CR] TKAs and 22 posterior-stabilized [PS] TKAs), and the correlations between the intraoperative values and the postoperative values assessed by stress radiographs at extension and flexion were examined at a minimum 5-year follow-up. In CR TKAs, the postoperative soft tissue balances at both angles were significantly correlated with the intraoperative values. In PS TKAs, the postoperative soft tissue balances at extension, not flexion, were significantly correlated with the intraoperative values. In conclusion, the intraoperative condition of the soft tissue balance reflected the postoperative values especially in CR TKAs even at 5-year midterm follow-ups.     

Quantitative evaluation of gait pattern in patients with osteoarthrosis of the knee before and after total knee arthroplasty. Gait analysis using a pressure measuring system

Using a pressure measuring system, we quantitatively evaluated gait pattern in patients with osteoarthrosis (OA) of the knee before and after total knee arthroplasty (TKA). In the OA group, the stance time was longer, and the average vertical component of the floor reaction force (AVF) was lower than the values in normal age-matched subjects. These gait parameters correlated with the clinical score. These results suggest that changes in the gait parameters reflect gait patterns that reduce load on the knee. The center of pressure (COP) under the foot was correlated with the axial alignment of the lower limb in the mid-stance phase. In the TKA group, the clinical scores and gait parameters were improved 12 months after surgery compared with the preoperative values. The COP in the mid-stance phase moved inward after the TKA. However, in patients examined more than 2 years after a TKA, stance time and AVF did not reach normal levels, despite the patients' good clinical scores. These findings indicate that the gait pattern before surgery continues although pain on walking is reduced early after a TKA. Gait evaluation with a simple pressure measuring system revealed the changes in gait that are difficult to define by subjective clinical assessment. Received for publication on April 13, 1998; accepted on Oct. 26, 1998     

Results of total hip and total knee arthroplasties in patients with synovial chondromatosis

This retrospective analysis examines the outcome of total joint arthroplasty for severe arthritis in patients with synovial chondromatosis. All 11 patients treated with total hip arthroplasty (n = 7) or total knee arthroplasty (n = 4) returned for follow-up at a mean of 10.8 years after surgery. Pain and functional scores improved significantly in all patients. Knee range of motion improved in all patients. Synovial chondromatosis recurred in 1 knee (25%) and 1 hip (14%). Total joint arthroplasty is a valuable treatment option for these patients with predictable improvement in pain and function. Knee range of motion is likely to improve but may be less than expected for primary total knee arthroplasty. Patients remain at risk for recurrence.     

Long-term survival analysis of the posterior cruciate condylar total knee arthroplasty: A 10-year evaluation

Long-term survivorship analysis was applied to 394 cruciate condylar type total knee arthroplasties. Clinical and radiographic parameters were evaluated. Failure was defined in three separate survival curves as revision, radiographic loosening, and a pain rating of 20 or less on the HSS knee score scale. Survival at 10 years, using only revision or recommended revision as the criterion for failure, was 94.7%. With the addition of the other two criteria, survival fell to 81% at 10 years. The posterior cruciate condylar knee survival is comparable to that of the total condylar knee when using comparable definitions of failure.     

Tibial post failures in a condylar posterior cruciate substituting total knee arthroplasty

In posterior-stabilized total knee arthroplasties, a femoral cam and polyethylene tibial post are commonly used to restore posterior stability after sacrifice of the posterior cruciate ligament. This article reports a high incidence of early tibial post failures in one design of prosthesis and examines the variables that may have contributed to such. Five hundred sixty-four consecutive posterior-stabilized total knees were implanted in 512 patients, using a total knee prosthesis with a polyethylene tibial post and femoral cam. Clinical and radiographic outcomes were measured at a mean follow-up of 40 months after surgery (range, 24-83 months). At follow-up, 70 knees in 62 patients (12%) had undergone revision surgery because of symptoms related to catastrophic failure of the tibial post.     

Correlation of posterior tibial slope with metaphysio-diaphyseal angle in total knee arthroplasty: A radiological study

Background:

Posterior tibial slope (PTS) is an important factor affecting postoperative range of motion (ROM) following total knee arthroplasty (TKA). Metaphysio-diaphyseal angle (MDA) is a new entity defined as angle between proximal anatomical axis and metaphyseal axis of tibia. This study was undertaken to determine PTS in Indian patients and find its correlation with MDA of tibia. Accuracy of extramedullary jigs and the influence of MDA on the accuracy was also evaluated. This study is a retrospective analysis of prospectively collected data in a tertiary healthcare center.

Materials and Methods:

Data of 100 consecutive patients undergoing TKA in a single center by a single surgeon was analyzed. Posterior cruciate ligament (PCL) substituting TKA was done with same jig to achieve different PTS in different patients. MDA, preoperative PTS and postoperative PTS were calculated. The data was analyzed using appropriate statistical analysis.

Results:

Mean preoperative PTS was 11.64° and mean MDA was 23.76° with a strong correlation between them (Pearson''s coefficient 0.72). Extramedullary jigs were accurate in 53% cases. In remaining 47%, postoperative PTS was less than planned PTS in 30%, and more in 17%. Mean postoperative PTS was 2.54°. In patients with MDA < 20°, postoperative PTS was significantly less (P = 0.0176) compared with those with MDA > 20°.

Conclusions:

The study establishes the positive correlation between MDA and PTS in Indians; and that MDA is an independent factor affecting accuracy of extramedullary jigs in TKA.     

Comparison of Contact Kinematics in Posterior-Stabilized and Cruciate-Retaining Total Knee Arthroplasty at Long-Term Follow-Up

BackgroundThere is controversy regarding the superiority of posterior-stabilizing (PS) total knee arthroplasty (TKA) and cruciate-retaining (CR) TKA. Substantial work has made comparisons between PS and CR TKA at follow-ups of less than 5 years. It was the goal of the present study to compare the kinematics at greater than 5 years postoperatively between CR and PS TKA, with a secondary goal of comparing patient function.MethodsA total of 42 knees were investigated, with equal representation in the PS and CR TKA groups. Patients underwent radiostereometric analysis imaging at 0°, 20°, 40°, 60° 80°, and 100° of flexion. Contact position, magnitude of excursion, and condylar separation on each condyle were measured. A Timed-Up-and-Go functional test was also performed by patients, with the total test time being measured. Preoperative and postoperative clinical outcome scores were also collected.ResultsThere were differences in contact position on both the medial and lateral condyles at multiple angles of flexion (P < .05). There was no difference (P = .89) in medial excursion; however, PS TKA had greater lateral excursion than CR TKA (P < .01). No difference (P > .99) was found in frequency of condylar separation. PS TKA was associated with faster (P = .03) total Timed-Up-and-Go test times. There were no differences in clinical outcome scores between the groups preoperatively or postoperatively.ConclusionWe found kinematic and functional differences that favor PS TKA. Our results suggest posterior cruciate ligament insufficiency in CR TKA, indicating that perhaps the cam/post systems in PS TKA better maintain knee kinematics and function long term.     

Comparison of posterior-stabilized,cruciate-retaining,and medial-stabilized knee implant motion during gait

Accurate knowledge of knee joint motion is needed to evaluate the effects of implant design on functional performance and component wear. We conducted a randomized controlled trial to measure and compare 6-degree-of-freedom (6-DOF) kinematics and femoral condylar motion of posterior-stabilized (PS), cruciate-retaining (CR), and medial-stabilized (MS) knee implant designs for one cycle of walking. A mobile biplane X-ray imaging system was used to accurately measure 6-DOF tibiofemoral motion as patients implanted with PS (n = 23), CR (n = 25), or MS (n = 26) knees walked over ground at their self-selected speeds. Knee flexion angle did not differ significantly between the three designs. Relative movements of the femoral and tibial components were generally similar for PS and CR with significant differences observed only for anterior tibial drawer. Knee kinematic profiles measured for MS were appreciably different: external rotation and abduction of the tibia were increased while peak-to-peak anterior drawer was significantly reduced for MS compared with PS and CR. Anterior-posterior drawer and medial-lateral shift of the tibia were strongly coupled to internal-external rotation for MS, as was anterior-posterior translation of the contact center in the lateral compartment. MS exhibited the least amount of paradoxical anterior translation of the femur relative to the tibia during knee flexion. The joint center of rotation in the transverse plane was located in the lateral compartment for PS and CR and in the medial compartment for MS. Substantial differences were evident in 6-DOF knee kinematics between the healthy knee and all three prosthetic designs. Overall, knee kinematic profiles observed for MS resemble those of the healthy joint more closely than PS and CR.     

Rotational kinematics of a modern fixed-bearing posterior stabilized total knee arthroplasty

The purpose of this study was to evaluate the rotational kinematics of a fixed-bearing posteriorly stabilized total knee design in moderate and deep flexion. Three-dimensional kinematics analyses were conducted on 20 knees in 4 weight-bearing positions using 3-dimensional shape-matching techniques. Average maximum skeletal flexion was 138 degrees . Internal tibial rotation was demonstrated in 19 of 20 knees. The average internal tibial rotation in midflexed lunge was 5.5 degrees (-3.8 degrees to 14.1 degrees ) and in maximum flexion kneeling was 4.0 degrees (-3.1 degrees to 10.6 degrees ). Separation of articular surfaces was not identified. In this study, patients with this device demonstrated patterns of rotation similar to those previously reported for both the normal knee and rotating platform designs.     

后稳定型全膝关节假体置换术后疗效分析

目的　分析后稳定型全膝关节假体置换术的处理方式、手术经验及疗效。方法　对 14例15膝行关节置换 ,使用Apollo后稳定型假体 ,单膝关节置换 13例 ,双膝同期置换 1例。原发疾病为类风湿性关节炎 3例 4膝 ,骨关节炎 11例 11膝。术后随访时间平均 11个月。结果　 15个膝关节术前伸曲活动度平均 75°,全膝关节置换术后 2个月关节活动度恢复至平均 10 0°。 14例患者均可自如行走、上下楼梯 ,膝关节稳定性好。 1膝术后脂肪液化致表层伤口裂开 ,清创后愈合 ,余膝术后伤口均愈合良好。结论　后稳定型假体植入的全膝关节置换手术方式简单、疗效肯定、术后并发症少。     

Cruciate-retaining total knee arthroplasty in patients with at least fifteen degrees of coronal plane deformity

There has been debate regarding the superiority of posterior stabilized (PS) or cruciate-retaining knee designs in total knee arthroplasty (TKA). The proponents of PS TKA argue that a relative contraindication to the use of cruciate-retaining total knee arthroplasty is that of significant coronal plane deformity. The purpose of this study is to compare our minimum 10-year results of posterior cruciate ligament-retaining TKAs in patients with preoperative coronal plane deformity of at least 15 degrees (> or =10 degrees of varus or > or =20 degrees of valgus) to historical results of PS TKA designs in similar patients. We found, at a minimum 10-year follow-up, very good results with a 93% (95% confidence interval, 87%-98%) revision-free survivorship at 10 years and no revisions for instability or loosening.     

Kinematic analysis of kneeling in cruciate‐retaining and posterior‐stabilized total knee arthroplasties

Kneeling is an important function of the knee for many activities of daily living. In this study, we evaluated the in vivo kinematics of kneeling after total knee arthroplasty (TKA) using radiographic based image‐matching techniques. Kneeling from 90 to 120° of knee flexion produced a posterior femoral rollback after both cruciate‐retaining and posterior‐stabilized TKA. It could be assumed that the posterior cruciate ligament and the post‐cam mechanism were functioning. The posterior‐stabilized TKA design had contact regions located far posterior on the tibial insert in comparison to the cruciate‐retaining TKA. Specifically, the lateral femoral condyle in posterior‐stabilized TKA translated to the posterior edge of the tibial surface, although there was no finding of subluxation. After posterior‐stabilized TKA, the contact position of the post‐cam translated to the posterior medial corner of the post with external rotation of the femoral component. Because edge loading can induce accelerated polyethylene wear, the configuration of the post‐cam mechanism should be designed to provide a larger contact area when the femoral component rotates. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:435–442, 2008