Simultaneous revision and contralateral primary total knee arthroplasty

BACKGROUND: There is controversy regarding whether simultaneous or staged bilateral total knee arthroplasty should be performed in patients with bilateral gonarthrosis. In addition, revision total knee arthroplasties have been less successful than primary arthroplasties. The purpose of this study was to evaluate the results of simultaneous revision and contralateral primary total knee arthroplasties performed during the same setting. METHODS: The study cohort included 150 knees in seventy-five patients who had undergone revision arthroplasty because of aseptic failure of a total knee arthroplasty and a contralateral primary arthroplasty for severe gonarthrosis under the same anesthetic. The study group was compared with a control group of sixty patients who had severe arthritis in one knee and had undergone unilateral revision total knee arthroplasty on the contralateral side. The duration of follow-up averaged five years in the group treated with the simultaneous arthroplasties and eight years in the control group. Clinical and radiographic results were evaluated with the Knee Society rating system. RESULTS: In the study group, the average knee score improved by 48 points on the side of the primary arthroplasty and by 37 points on the side of the revision. At the last follow-up visit, most (sixty-five) of the seventy-five patients stated that the knee with the revision felt better than the knee with the simultaneously performed primary arthroplasty. In the control group, the average knee score improved by 30 points on the side of the revision arthroplasty. However, forty-five of the sixty patients had a primary total knee arthroplasty on the contralateral side within two years after the index revision arthroplasty; by four years, all sixty patients had undergone a contralateral primary arthroplasty. CONCLUSIONS: We found a favorable outcome in patients who had undergone simultaneous revision and contralateral primary total knee arthroplasties. Despite a lower mean knee score and less motion, most patients seemed to prefer the knee with the revision arthroplasty to the knee with the primary procedure. These results suggest that this combined procedure is a safe and favorable alternative to a staged procedure consisting of revision and subsequent contralateral primary total knee arthroplasty.     

全膝关节置换术后主动和被动锻炼促进关节功能恢复的前瞻性研究

目的 探讨全膝关节置换(TKA)术后持续被动活动和主动功能锻炼对患者关节功能康复效果的影响. 方法采用前瞻性研究方法,选取2007年2月至2008年6月行TKA的80例患者为研究对象,所有患者按入院序号应用随机数字表法分为持续被动活动组(CPM组)和主动功能锻炼组(AP组),每组40例.CPM组术后早期应用CPM机行康复治疗,AP组则在专业康复医师指导下进行主动功能锻炼.记录患者术后第3、6、9天时的VAS评分,术后第3、6、9天、出院及随访时的关节活动度,患者住院天数.采用美国膝关节外科学会的评分系统(KSS)对患者术前、术后3、6个月随访时的患膝关节功能进行评分. 结果术后第3天,CPM组、AP组的平均VAS评分分别为2.37、3.02分,差异有统计学意义(t=-2.52,P=0.03).术后第6、9天两组患者平均VAS评分差异均无统计学意义(P>0.05).术后3、6、9 d及出院时两组患者的关节活动度差异均无统计学意义(P>0.05).56例患者(CPM组30例,AP组26例)获得随访.术后3个月,CPM组、AP组患者的关节活动度为别为105.50°、112.96°,差异有统计学意义(P=0.04),但术后6个月时两组差异无统计学意义(P>0.05).术后3、6个月两组患者KSS评分差异均无统计学意义(P>0.05). 结论 TKA术后功能恢复应强调主动功能锻炼而非被动锻炼.不推荐常规应用CPM,但对痛觉过敏及无法进行主动功能锻炼的患者,仍应考虑CPM辅助治疗,以促进关节功能的恢复.     

全膝关节置换术后主动和被动锻炼促进关节功能恢复的前瞻性研究

目的 探讨全膝关节置换(TKA)术后持续被动活动和主动功能锻炼对患者关节功能康复效果的影响. 方法采用前瞻性研究方法,选取2007年2月至2008年6月行TKA的80例患者为研究对象,所有患者按入院序号应用随机数字表法分为持续被动活动组(CPM组)和主动功能锻炼组(AP组),每组40例.CPM组术后早期应用CPM机行康复治疗,AP组则在专业康复医师指导下进行主动功能锻炼.记录患者术后第3、6、9天时的VAS评分,术后第3、6、9天、出院及随访时的关节活动度,患者住院天数.采用美国膝关节外科学会的评分系统(KSS)对患者术前、术后3、6个月随访时的患膝关节功能进行评分. 结果术后第3天,CPM组、AP组的平均VAS评分分别为2.37、3.02分,差异有统计学意义(t=-2.52,P=0.03).术后第6、9天两组患者平均VAS评分差异均无统计学意义(P>0.05).术后3、6、9 d及出院时两组患者的关节活动度差异均无统计学意义(P>0.05).56例患者(CPM组30例,AP组26例)获得随访.术后3个月,CPM组、AP组患者的关节活动度为别为105.50°、112.96°,差异有统计学意义(P=0.04),但术后6个月时两组差异无统计学意义(P>0.05).术后3、6个月两组患者KSS评分差异均无统计学意义(P>0.05). 结论 TKA术后功能恢复应强调主动功能锻炼而非被动锻炼.不推荐常规应用CPM,但对痛觉过敏及无法进行主动功能锻炼的患者,仍应考虑CPM辅助治疗,以促进关节功能的恢复.     

Antibiotic-loaded cement articulating spacer for 2-stage reimplantation in infected total knee arthroplasty: a simple and economic method

We presented a simple and economic method of preparing articulating antibiotic-loaded cement spacers for treatment of infection after total knee arthroplasty. From 1996 to 2004, 28 infected total knee arthroplasties were treated with 2-stage reimplantation. Static spacers were used in 7 knees, and articulating spacers were used in 21 knees. A minimum of 2 years' follow-up after final treatment was evaluated. In the static group, 1 (14%) knee had recurrence of infection. In the articulating group, 2 (9%) knees had recurrence of infection with the original organism. Patients receiving articulating spacer had better range of motion, better knee score, and less bone loss than patients with static spacer.     

The effects of implant design on range of motion after total knee arthroplasty. Total condylar versus posterior stabilized total condylar designs.

Range of motion (ROM) after total knee arthroplasty (TKA) is an important variable in determining clinical outcome. Recent design modifications have been aimed at improving final motion. The posterior stabilized total knee prosthesis was introduced as a modification of the total condylar design, changing the center of curvature of the femoral component to allow greater ROM. In this study, all primary TKAs performed at the authors' institution from July 1982 until December 1986 were reviewed to determine the effect of this design modification on outcome. A total condylar (TC) group comprised 51 arthroplasties and was compared to 53 arthroplasties in a posterior stabilized (PSTC) group. the postoperative protocol was identical in both groups. The mean postoperative flexion was 11 better in the PSTC group; however, the mean preoperative flexion had initially been 10 degrees better in the PSTC group. The maximum flexion achieved by any patient in both groups was similar, but the TC group actually gained slightly more arc of motion. The better motion in the PSTC group may be secondary to better motion preoperatively and not implant design in this series. The more limited the preoperative ROM, the greater the quadriceps stiffness is likely to be, which is an important determinant of postoperative flexion. Review of the literature supports present observations that a group with less mean preoperative motion paradoxically gains a slightly greater increment of flexion. Differences in flexion after TKA are difficult to attribute to design in either the current study or by a review of the literature. This is because determinants of flexion after TKA are multifactorial and outcome data limited, notwithstanding the similarities among modern prostheses.     

Simultaneous bilateral total knee arthroplasties: who decides?

The purpose of the current retrospective review was to compare the results of 1498 patients having 1090 simultaneous bilateral total knee arthroplasties and 958 unilateral total knee arthroplasties in a 3-year period, focusing on perioperative complications, length of hospital stay, and discharge disposition. Gender, age, diagnosis, and weight were similar between the groups. Patients undergoing simultaneous bilateral total knee arthroplasties had statistically significant higher amounts of intraoperative blood loss, with more patients requiring blood transfusion, and a higher average number of units of blood transfused compared with patients undergoing unilateral total knee arthroplasty. Overall, a significantly higher incidence of gastrointestinal complications was reported in patients who had simultaneous bilateral knee arthroplasties compared with patients who had unilateral knee arthroplasty. Comparing age subgroups within the unilateral group revealed significantly higher incidences of pulmonary, neurologic, cardiac, and genitourinary complications among patients 80 years or older versus patients younger than 80 years. Patients having simultaneous bilateral arthroplasties who were 80 years or older had significantly higher incidences of pulmonary, neurologic, and cardiac complications than patients younger than 80 years in that same group. These results suggest that age, not procedure, has a more significant role in the perioperative morbidity of total knee arthroplasty. Based on the results from the current study and previous literature documenting patient preference, patient satisfaction, efficacy, and outcomes comparable with those of patients having unilateral total knee arthroplasty, the authors continue to offer patients the option of simultaneous bilateral total knee arthroplasties.     

Home continuous passive motion machine versus professional physical therapy following total knee replacement

A vigorous rehabilitation program following discharge from the hospital is necessary for patients having a total knee arthroplasty to maintain and improve range of motion and function. To compare the effectiveness of the continuous passive motion (CPM) machine as a home therapy program versus professional physical therapy, a prospective, comparative, randomized clinical study of 103 consecutive primary total knee arthroplasties in 80 patients (23 bilateral) was performed. The CPM group consisted of 37 patients (49 knees), and the physical therapy group consisted of 43 patients (54 knees). At 2 weeks, knee flexion was similar in the two groups, but a flexion contracture was noted in the CPM group (4.2°). This difference is felt by the authors to be clinically insignificant. At 6 months, there were no differences in knee scores, knee flexion, presence of flexion contracture, or extensor lag between the two groups. The cost for the CPM machine group was $10,582 ($286 per patient), and the cost for professional therapy was $23,994 ($558 per patient). We conclude that the CPM machine after the hospital discharge of patients having total knee replacement is an adequate rehabilitation alternative with lower cost and with no difference in results compared with professional therapy.     

Is obesity a contraindication to bilateral total knee arthroplasties under one anesthetic?

Three-hundred sixteen patients who underwent 405 primary knee replacements between January 1994 and June 1999 were reviewed for the incidence of local wound and systemic complications after unilateral and simultaneous bilateral total knee arthroplasties. A body mass index of 30 or greater was used to define obesity, and patients were divided into four groups based on obesity and whether they were undergoing unilateral or bilateral total knee arthroplasties. Preoperative and postoperative knee scores were not significantly different for any patient group. Local wound complication rates did not differ between any of the study groups. Patients who were not obese who underwent unilateral total knee arthroplasty had lower systemic complication rates (3%) than the other groups; however, there was no significant difference in complication rates between patients with obesity who underwent unilateral or simultaneous bilateral total knee arthroplasties. Based on these findings, obesity does not seem to be a contraindication to bilateral total knee arthroplasties under one anesthetic.     

术前活动度对人工全膝关节置换术后功能影响的观察

目的回顾性分析患者手术前的活动度对人工全膝关节置换(TKA)术后功能的影响。方法随访2000年1月—2003年12月在我科行TKA的患者65例(97膝),年龄64．8±9．9岁(35～85岁)。其中骨性关节炎55例(81膝),类风湿关节炎10例(16膝)。单膝置换33例,双膝同时置换32例。所有患者按术前膝关节活动度数(ROM)分成两组,≤90°(5°～90°)49膝,>90°(95°～140°)48膝。对两组患者进行疗效(最大屈膝度、活动度、KSS评分及功能评分)对比。所有患者均采用Scorpio后稳定型骨水泥固定的假体,均为初期置换,全部手术由同一组医师完成。术后3 d在同一康复师指导下行患肢CPM及主动功能锻炼至出院。结果平均随访时间29个月(10～44个月)。所有膝关节的活动度从术前的平均84．2°(5°～140°)提高到术后的平均101．6°(40°～140°) (P=0．000);而最大屈膝度数术前的平均103．5°(25°～140°)与术后的平均101．6°(40°～140°)无显著差异(P=0．439);KSS膝关节评分从术前平均19．5分(-24～62分)提高到术后平均78．8分(50～95分)(P=0．000)。所有患者的总满意度为93．8％(61／65)。两个分组比较,ROM≤90°的膝关节ROM及最大屈膝度术后均较术前有提高,而ROM>90°的膝关节平均最大屈膝度术后反而下降。没有翻修及深部感染。结论(1)在影响TKA术后膝关节功能的多种因素中,手术技术是关键因素。(2)在其他因素相同的情况下,术前膝关节的活动度对TKA术后的功能也有很大的影响,术前活动度大的膝关节比那些术前活动度小的膝关节术后能获得更好的功能。     

Continuous passive motion compared to active physical therapy after knee arthroplast:Similar hospitalization times in a randomized study of 68 patients

68 consecutive patients who had primary knee arthroplasties because of arthrosis were randomized to postoperative continuous passive motion (CPM) or active physical therapy (APT). Rehabilitation in both groups was initiated on the first postoperative day. The CPM group sustained less postoperative knee swelling with more rapid initial improvement in knee flexion than did the APT group, but there were no differences between the groups in knee flexion at discharge. Postoperative pain rating and hospitalization times were similar in the two groups.     

Bilateral total knee arthroplasty increases the propensity to trip on an obstacle

Tripping over an obstacle is the most frequent cause of falls. We examined the effects of total knee arthroplasty on obstacle avoidance success rates in older adults. Obstacle avoidance success rates, body mass index, visual acuity, contrast sensitivity, depth perception, and single-leg stance duration were evaluated in 29 subjects who had bilateral total knee arthroplasties (age range, 72.6 +/- 5.4 years) and 27 age-matched healthy control subjects (age range, 70.6 +/- 5.5 years). The patients who had total knee arthroplasties had a lower obstacle avoidance success rate, lower single-leg stance duration, and greater body mass index than control subjects. Age, contrast sensitivity, and depth perception were not different between patients who had total knee arthroplasties and control subjects. Obstacle avoidance success rates decreased linearly as single-leg stance duration decreased in the control group and across all groups, but not in the group that had total knee arthroplasties. Linear relationships between obstacle avoidance success rates and body mass index existed for all subjects but not for the group that had total knee arthroplasties or the control group individually. Total knee arthroplasty reduces obstacle avoidance success rate, suggesting that persons who have total knee arthroplasties have an increased propensity to trip on an obstacle and fall. Increased body mass index and decreased single-leg stance duration in patients who have total knee arthroplasties are associated with a decreased obstacle avoidance success rate.     

Conversion of patellofemoral arthroplasty to total knee arthroplasty: A matched case-control study of 13 patients

Background and purpose The long-term outcome of patellofemoral arthroplasty is related to progression of femorotibial osteoarthritis with need for conversion to total knee arthroplasty. We investigated whether prior patellofemoral arthroplasty compromises the results of total knee arthroplasty.Methods 13 patients who had had 14 Richards type II patellofemoral arthroplasties converted to total knee arthroplasty because of femorotibial osteoarthritis, were individually matched to a control group of 13 patients with 14 primary total knee arthroplasties. The mean follow-up times for the patients and the control group were 5.7 (2–13) years and 5.2 (2–13) years, respectively. Clinical outcome was assessed using Knee Society score (KSS), WOMAC score, range of motion, and complications.Results KSS and WOMAC scores were similar in the two groups (KSS in patient and control groups: 82 and 86 (p = 0.6); KSS function: 76 and 88 (p = 0.5); WOMAC score: 33 and 21 (p = 0.1)). Within 6 months after conversion, 3 knees had to be manipulated under anesthesia for limited motion. No patients in the control group required manipulation under anesthesia.Interpretation Patellofemoral arthroplasty appears not to have a negative effect on the outcome of later total knee arthroplasty.     

Effect of adjunctive range-of-motion therapy after primary total knee arthroplasty on the use of health services after hospital discharge.

INTRODUCTION: There is controversy as to whether continuous passive motion (CPM) after total knee arthroplasty (TKA), which is the standard treatment, confers significant benefit with respect to outcome. The primary purpose of this study was to determine if CPM or slider-board (SB) therapy, used as adjuncts to standardized exercises (SEs) during the acute-care hospital stay, resulted in a reduced total length of hospitalization and post-discharge rehabilitation in patients who underwent primary TKA. METHODS: We carried out a randomized, clinical trial on 120 patients who received a TKA at the University of Alberta Hospital, Edmonton, a tertiary care institution. The study horizon began at the point of discharge from the hospital and continued up to 6 months after operation. Postoperatively, patients (40 in each group) received CPM and SEs, SB therapy and SEs or SEs alone while in the tertiary Health service use was compared using transfer institution length of stay(LOS), post-discharge rehabilitation, readmission and complication rates and their associated costs. RESULTS: There were no differences in health service use or costs among the 3 groups over the 6-month study. The rates of postoperative complications and readmissions also were similar among the groups. Increased health service use associated with knee flexion that was less than 60 degrees at discharge, but similar proportions of patients with poor knee range of movement (ROM) at discharge were found in each group. CONCLUSIONS: This finding suggests that adjunctive ROM therapy, as used in this study, does not reduce health service use. Further research is required to determine if adjunctive ROM therapy after discharge from the surgical hospital decreases health service utilization in those patients who have poor knee ROM at the time of discharge.     

The influence of continuous passive motion on outcome in total knee arthroplasty

All primary condylar total knee replacement arthroplasties (TKAs) performed from 1977 to 1984 at the authors' institution were divided into two groups based on the use of continuous passive motion (CPM) in the immediate postoperative period. The control group consisted of 73 patients who were treated with 95 TKAs without postoperative CPM. The average age was 65.4 years. The study group consisted of 38 patients who had 51 TKAs in which CPM was used postoperatively. The mean patient age was 62.8 years. The most common diagnoses in both groups were osteoarthritis and rheumatoid arthritis. Range of motion (ROM) was recorded preoperatively, at discharge, at three months, one year, two years, and at the last follow-up visit. There were no statistically significant differences in the ROM between the two groups at any of these time periods. At two years, the mean flexion and extension in the study group were 99 degrees and -4 degrees, respectively, compared to 103 degrees and -5 degrees in the control group. The average hospital stay was 11.2 days in the study group, whereas it was 15.1 days in control group. In the control group, there was one superficial infection, no deep infections, and four pulmonary emboli compared with three superficial infections, two deep infections, and no pulmonary emboli in the study group. There was no difference in the transfusion requirements between the two groups. CPM is advocated by the authors to help achieve discharge ROM earlier, but the protocol has been changed to begin CPM on the second postoperative day to allow the wound to stabilize.     

Femoral corrective osteotomy for malunited supracondylar femoral fracture after TKA in a patient with rheumatoid arthritis

This article presents a case of femoral corrective osteotomy for malunited supracondylar femoral fracture after total knee arthroplasty (TKA) in a patient with rheumatoid arthritis. The patient underwent 1-stage bilateral TKA and 2-stage bilateral total hip arthroplasty 17 years prior at our institution. Her fall 10 years before led to a supracondylar femoral fracture that was treated nonoperatively for 3 months and led to malunion. Complaints of mild right knee pain and remarkable varus deformity were observed. On examination, the right knee was not swollen and tender. Range of motion (ROM) of the right knee was 0° to 130°. The patient needed crutches to ambulate. Knee score and function scores, according to the Knee Society clinical rating system, were 65 and 25 points, respectively. Radiographs after malunion showed remarkable varus knee and the femorotibial angle was 197°. At the time of surgery, the components were stable and bone union was completed. Valgus corrective osteotomy of the femur was performed using a retrograde intramedullary nail, with satisfactory results at 10-year follow-up. The patient is able to walk without a cane and has 0° to 130° ROM. Knee and function scores were 88 and 80 points, respectively. Radiographs showed complete bone union and the femorotibial angle was 179° with no loosening of the prostheses. Femoral corrective osteotomy is recommended for malunited supracondylar femoral fracture after TKA.     

The ball and socket articulating spacer for infected total knee arthroplasty

Articulated antibiotic impregnated cement spacers permit knee motion and may facilitate patient mobilization during 2-stage treatment of infected total knee arthroplasty (TKA). However, molds for articulating knee spacers are not always readily available. We have treated 13 infected total knee arthroplasties with large bone defects or collateral ligament loss using the rubber bulb portion of an irrigation syringe and a bipolar trial to create a ball and socket articulating spacer. This technique was successful in controlling infection in 9 of 13 knees. All patients were able to ambulate independently with the spacer in place using a walker or crutches, including one patient with bilateral spacers. At an average follow-up of 28 months after reimplantation, average knee flexion was 98 degrees .     

Unicompartmental versus total knee arthroplasty in the same patient. A comparative study

The purpose of this study was to compare unicompartmental knee arthroplasty (UKA) with total knee arthroplasty (TKA) and more specifically to evaluate the role of the patella in patient preference between UKA and TKA. A group of 23 patients were chosen, each with a UKA in one knee and a TKA in the opposite knee. As a subset of the group, 13 patients were compared who had not had patellar resurfacing on their TKA side (Group A) versus ten patients who had patellar resurfacing (Group B). Each patient had a UKA and TKA performed during the same hospitalization. Each patient's resurfacing was performed by the same surgical team. Moreover, inpatient care and physical therapy for each patient's respective UKA and TKA were the same. Patient evaluation consisted of chart review, joint registry data, and telephone interviews that focused on patient preference regarding pain, stability, "feel," and ability to climb stairs. The 23 patients studied had an average follow-up period of 81 months (range, 38-153 months). There were 14 men and ten women with an average age of 67 years. Preoperative diagnosis was osteoarthritis in 22 patients and rheumatoid arthritis in one patient. Range of motion (ROM) improved from a preoperative mean of 106 degrees to 123 degrees postoperatively on the UKA side. Mean ROM for the Group A TKAs improved from 104 degrees to 109 degrees, whereas the Group B TKAs remained unchanged at 113 degrees. For patients surveyed in Group A, 31% stated that their UKA knee was their better knee overall, 15% stated that their TKA knee was their better knee overall, and 54% could find no difference.(ABSTRACT TRUNCATED AT 250 WORDS)     

Continuous passive motion after total knee arthroplasty

Sixty-two patients undergoing primary total knee arthroplasty were studied prospectively. There were 42 patients in whom continuous passive motion (CPM) was used after surgery and 20 controls. The two groups were comparable with respect to age, diagnosis, sex, weight, and preoperative deformity and motion. The mean length of time required for CPM patients to achieve 90 degrees of flexion (9.1 days) was shorter than that for the control group (13.8 days). At the time of discharge from the hospital, however, there was no significant difference between the groups in amount of either flexion or extension. All patients had venograms performed after arthroplasty; the incidence of positive studies indicating thrombophlebitis was 45% in CPM patients and 75% in controls. These data demonstrate that CPM after knee arthroplasty enables patients to recover motion more quickly and affords some protection against deep vein thrombosis.     

不同程度屈膝挛缩畸形人工全膝关节置换的早期疗效比较

目的探讨不同程度屈膝挛缩畸形行人工全膝关节置换术(totalkneearthroplasty,TKA)后的早期疗效。方法回顾性分析2000年1月～2003年12月行TKA的65例97膝屈膝挛缩畸形患者资料。其中骨关节炎51例74膝,类风湿关节炎14例23膝。单膝置换33例33膝,双膝同时置换32例64膝。按屈膝挛缩畸形程度不同将患者分成A、B两组,A组屈曲挛缩<20°(0～15°)32例49膝,B组屈曲挛缩≥20°(20～60°)33例48膝。A、B两组膝关节术前屈曲挛缩度数、活动度(rangeofmotion,ROM)、KSS(kneesocietyscore)评分及功能评分分别为10.7±8.0°、104.6±20.0°、29.1±18.0、32.6±20.7和28.2±7.8°、60.8±26.6°、12.1±13.2、26.8±18.1,各指标组间比较差异均有统计学意义(P<0.05)。术中均采用Scorpio后稳定型骨水泥固定假体,行初期置换。术后3～4d在同一康复师指导下行CPM及主动功能锻炼。结果患者获随访8个月～3年6个月,平均2年7个月。A、B组术后膝关节屈曲挛缩度数、ROM、KSS评分和功能评分分别为0.4±2.1°、108.6±19.0°、82.1±13.8、72.3±29.1和1.3±3.2°、98.6±16.4°、75.9±8.2、81.4±26.9,组间比较差异均无统计学意义(P>0.05)。术后患者总满意度为94.6%,无深部感染及再翻修者。结论膝关节屈膝挛缩畸形严重与否对TKA的早期疗效无明显影响;TKA后ROM有“趋中”现象;术后早期行膝关节功能锻炼也是获得功能改善的重要环节之一。     

The effect of tibial polyethylene insert design on range of motion: evaluation of in vivo knee kinematics by a computerized navigation system during total knee arthroplasty

Computer-assisted navigation for total knee arthroplasty offers the unique opportunity to assess in vivo knee kinematics during surgery and implement changes whenever appropriate. Using a computerized navigation system, the effect of 2 tibial polyethylene insert designs on knee kinematics in general and knee range of motion (ROM) in particular was evaluated in 37 knee arthroplasties in 30 patients. The Scorpioflex tibial insert was found to provide a significant increase in mean extension, mean flexion, and overall ROM of the knee compared with the standard tibial insert (P<.005) without affecting knee ligamentous balance. Navigation is a very effective and useful tool for intraoperative assessment of knee kinematics and accurate recording of ROM. Based on the information obtained from the navigation software, the surgeon can implement changes in selection of the knee components with beneficial effects in knee kinematics in general and knee ROM in particular. This may, in turn, translate to better clinical outcome of the knee arthroplasty.