Patients with fixed flexion deformity after total knee arthroplasty do just as well as those without: ten-year prospective data

Range of motion (ROM) is an important outcome variable after total knee arthroplasty (TKA). This may be compounded by a pre-existing fixed flexion deformity (FFD). We therefore examined the long-term outcomes of patients with a flexion deformity undergoing TKA compared to those without a preoperative fixed flexion deformity. Participants who had undergone TKA at our centre between 1989 and 2002 were examined preoperatively, one, five and ten years after TKA (Kinemax PS; Howmedica, Rutherford, NJ, USA). Examining those with a preoperative FFD of greater than ten degrees with complete ten year follow-up data revealed 77 individuals. Seventy seven age, sex and body mass index matched patients were identified and the effect of TKA on indices of knee function (fixed flexion, maximum flexion, total ROM and Knee Society score (KSS) in both groups were analysed using repeated measures ANOVA. A significant difference between the groups with respect to fixed flexion (p < 0.001), total ROM (p = 0.001) and KSS (p < 0.001) was observed between baseline and year one suggesting that those with a preoperative FFD improved more than those without. A significant difference with regard to fixed flexion was also observed between years one to five (p = 0.001) and just failed to reach statistical significance between five to ten years (p = 0.052) between the groups. This study demonstrates that patients with a preoperative fixed flexion deformity show continued improvement in their fixed flexion up to ten years post arthroplasty and have similar outcomes to those with no preoperative fixed flexion.     

Effect of body mass index on range of motion and manipulation after total knee arthroplasty

This study evaluates the effects of increased body mass index (BMI) on postoperative range of motion (ROM) and rate of manipulation under anesthesia (MUA) after total knee arthroplasty (TKA) in 391 primary TKAs. Range of motion and incidence of MUA were retrospectively collected and compared between 4 BMI groups (I, BMI <25; II, BMI 25-29.9; III, BMI 30-34.9; IV, BMI >35) using χ² or Fisher exact tests. Patients with higher BMIs had a greater incidence of MUA (I, 9.7%; II, 19%; III, 20%; IV, 15%) and lower preoperative and postoperative ROM. Women had lower ROM and a higher rate of MUA. Age was not a significant predictor of ROM or rate of MUA. Patients at greater risk of complications after TKA should be counseled about realistic surgical outcomes.     

Comparison of Cruciate-Sacrificing vs Posterior-Stabilized Total Knee Replacement Using a Contemporary Total Knee System

BackgroundThe use of highly conforming polyethylene tibial inserts in cruciate-retaining total knee arthroplasty (TKA) often requires posterior cruciate ligament (PCL) release/sacrifice for balancing (CS TKA). The CS TKA relies on the posterior capsule, collateral ligaments, and articular conformity without a cam or post to achieve stability. Using prospectively collected data we compared clinical outcomes of CS TKA to posterior-stabilized (PS) TKA utilizing a contemporary TKA system.MethodsSixty-nine consecutive CS TKAs were compared to 45 consecutive PS TKAs at 2-year minimum follow-up. CS knees were balanced with the PCL released. Preoperative/postoperative range of motion (ROM), Knee Society Scores (KSS), stair function, and squatting ROM were analyzed.ResultsAt minimum 2-year follow up, CS and PS TKA demonstrated significant improvement in ROM (P < .001), KSS (Pain, P < .001; Function, P < .001), and KSS stair function (P < .001), with no revisions. There was no difference in preoperative to postoperative improvements for passive knee ROM (10° (0°-20°) vs 13° (5°-25°); P = .16), KSS Pain (34 (21-42) vs 38 (24-46); P = .22), KSS Function (35 (30-50) vs 35 (18-50); P = .34), and KSS stair function (10 (10-20) vs 10 (0-20); P = .37) for CS and PS TKA, respectively. CS TKA had higher squatting ROM (P = .02) at minimum 2-year follow-up compared to PS TKA.ConclusionBoth PS and CS TKA provided significant improvement in clinical outcomes, with no differences in passive ROM, KSS, or stair function postoperatively. Our data support that with proper articular conformity and balancing, cruciate-retaining TKA in a PCL-deficient knee (CS TKA) is appropriate. This may be design specific and further prospective randomized studies are needed to corroborate these findings.     

小切口辅助手法松解治疗TKA术后关节僵硬

目的探讨髌外侧小切口辅助麻醉下手法松解治疗初次全膝关节置换术后早期膝关节僵硬的临床疗效。方法对10例初次全膝关节置换术后早期（6周内）发生膝关节僵硬的患者行髌外侧小切口辅助麻醉下手法松解。其中男性3例,女性7例;术前膝关节平均活动度为（74.4±9.44）°（60°～85°）,平均年龄（72.8±7.18）岁（59～81岁）。排除因感染、假体松动、假体位置不良等明确原因导致术后关节僵硬的患者。术中给予蛛网膜下腔麻醉,反复、柔和、持续地对膝关节进行手法松解,结合髌外侧小切口,使其达到最大的活动度。采用KSS评分对膝关节术前及术后功能进行评价。结果平均随访（2.6±1.04）年（1～4年）,术中能达到的平均活动度为（112.5±9.20）°（100°～125°）,末次随访时平均活动度为（105±6.97）°（95°～115°）。KSS评分从术前平均69分提高到末次随访时平均82分。术前术后KSS评分差异有统计学意义（t=14.40,P〈0.01）。结论髌外侧小切口辅助麻醉下手法松解是治疗初次全膝关节置换术后早期发生膝关节僵硬安全、有效的治疗手段,通过早期治疗,能显著改善膝关节功能。     

高屈曲垫片与标准垫片全膝关节置换的早期疗效对照研究

目的 比较采用高屈曲垫片与标准垫片的膝关节假体行全膝关节置换术的早期临床疗效.方法 2005年2月至2008年7月采用GenesisⅡ型膝关节假体行初次全膝关节置换术203例216膝,随机分为高屈曲垫片组(A组,98例107膝)与标准垫片组(B组,105例109膝).术前两组膝关节协会评分(Knee Society score,KSS)系统中的膝评分及膝关节功能评分和膝关节活动度的差异均无统计学意义.术后2周、6周、3个月、6个月、1年及以后每年随访1次.以术后1年为观测终点,观察并发症发生情况,比较两组的KSS膝评分、KSS膝关节功能评分及膝关节活动度.结果 术后1年A组随访91例98膝,B组94例96膝.膝关节主动屈伸活动度A组121.1°±6.9°,B组118.6°±8.1°;膝关节主动屈伸活动度改善度A组17.1°±13.3°,B组16.1°±18.8°;膝关节被动屈伸活动度A组127.2°±7.1°,B组121.0°±7.8°;KSS膝评分A组(86.9±7.6)分,B组(87.5±6.8)分;KSS膝关节功能评分A组(91.2±8.7)分,B组(90.1±9.3)分.其中两组膝关节被动屈伸活动度的差异有统计学意义.术后发生深静脉血栓形成A组4例,B组3例;切口脂肪液化A组3例,B组5例;术后粘连A组2例,B组3例.结论 应用GenesisⅡ型膝关节假体行全膝关节置换术时,选择高屈曲垫片者术后早期膝关节被动屈伸活动范围大于选择标准垫片者,而在主动屈伸活动范围及关节功能评分方面无差异.     

Improved Range of Motion and Patient-Reported Outcome Scores With Fixed-Bearing Revision Total Knee Arthroplasty for Suboptimal Axial Implant Rotation

BackgroundSuboptimal implant rotation has consequences with respect to knee kinematics and clinical outcomes. We evaluated the functional outcomes of revision total knee arthroplasty (TKA) for poor axial implant rotation.MethodsWe retrospectively reviewed 42 TKAs undergoing aseptic revision for poor axial implant rotation. We assessed improvements in Knee Society Score (KSS) and final range of motion (ROM). Subgroup analyses were performed for preoperative instability and stiffness, as well as the number of components revised and level of implant constraint used.ResultsRevision for poor axial rotation in isolation improved KSS from 52 ± 22 to 84 ± 25 (P < .001), and flexion increased from 105 ± 21° to 115 ± 13° (P = .001). Revision in the setting of instability significantly improved the KSS (P < .001) but did not affect ROM (P = .172). Revision in the setting of stiffness significantly improved both KSS (P < .001) and ROM (P = .002). There was no statistically significant difference between the postoperative KSS (P = .889) and final knee flexion (P = .629) with single- or both-component revision TKA for isolated poor axial rotation or between the postoperative KSS (P = .956) and final knee flexion (P = .541) with or without the use of higher constraint during revision TKA for isolated poor axial rotation.ConclusionRevision TKA for poor axial alignment improves clinical outcomes scores and functional ROM.     

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。     

Surgeon’s expectations do not predict the outcome of a total knee arthroplasty

Introduction  It is fascinating for both the patient and the surgeon to predict the outcome of a TKA at an early stage. Satisfaction after TKA is primarily determined by the preoperative expectations of the patient. The purpose of this study was to investigate if the peri-operative expectations of the surgeon predicted the outcome of a TKA. Patients and methods  A prospective study of 53 primary TKAs was performed. Preoperatively, the surgeon described the assessment of the difficulty of the TKA on a VAS. Immediately postoperative, the surgeon gave his satisfaction VAS about the procedure. After 1 year the surgeon’s satisfaction VAS, the patient’s satisfaction VAS and the KSCRS were determined. Results  The Spearman’s correlation coefficients between the preoperative difficulty assessment, the immediate postoperative satisfaction and the outcome measurements after 1 year were all very poor (−0.01 to 0.23). Conclusions  The outcome of a TKA depends on multiple factors. Both the surgeon’s preoperative assessment of the difficulty and the surgeon’s immediate postoperative satisfaction do not independently predict the outcome of a TKA.     

Average 7-Year Survivorship and Clinical Results of a Newer Primary Posterior Stabilized Total Knee Arthroplasty

We evaluated the average 7-year survivorship and clinical results of a newer primary posterior stabilized total knee arthroplasty (TKA). The modifications in this design included a deeper patellar sulcus aimed at reducing contact stresses, improving patellar tracking, and achieving greater maximum flexion. A consecutive group of 137 patients (171 knees) who underwent TKAs using the Optetrak PS knee prosthesis between October 1997 and March 2004 were followed for an average of 6.8?years (range 4.0-11.5?years). Preoperative range of motion (ROM) and Knee Society scores were obtained and compared to that of the patients' most recent follow-up. Manipulation under anesthesia (MUA) and revision of the implant for any reason were considered endpoints for Kaplan-Meier survival analysis of all knees. Twenty-one knees (12.3%) underwent MUA. Three knees (1.8%) underwent revision, resulting in a 97.2% survival at a mean 10?years follow-up. Pain scores and ROM significantly improved after surgery (from preoperative average of 5.3 and 105° respectively to 44.6 and 120° postoperatively). These findings suggest that this posterior stabilized knee design is both a safe and effective option for patients undergoing primary TKA.     

Outcome of Revision Surgery for the Idiopathic Stiff Total Knee Arthroplasty

BackgroundIdiopathic stiff total knee arthroplasty (TKA) represents one of the most challenging subsets of the stiff TKA, as the etiology is unknown and there is no consensus on the most appropriate surgical treatment modality. Therefore, the aim of this study is to report on postoperative outcomes of revision surgery for idiopathic stiff TKA.MethodsWe retrospectively reviewed 189 consecutive patients (202 knees) who underwent revision TKA for stiffness: (1) 101 knees in the idiopathic stiffness cohort and (2) 88 in the non-idiopathic stiffness cohort. In the idiopathic stiffness cohort, 42 knees underwent isolated tibial insert exchange and 59 knees underwent component revision. Perioperative knee range of movement and complications were analyzed.ResultsThe overall revision surgery outcomes of the idiopathic stiffness cohort were worse than those of the non-idiopathic stiffness cohort with regard to maximum flexion (91.7° vs 100.1°, P = .02) and flexion range of motion (ROM) (87.6° vs 97.1°, P = .01). In the idiopathic stiffness cohort, isolated tibial insert exchange demonstrated greater maximum flexion (96.8° vs 88.4°, P = .06) and flexion ROM (93.2° vs 83.9°, P = .07). In terms of re-revision rates, the isolated tibial insert exchange idiopathic stiffness cohort demonstrated lower re-revision rates compared to the component revision idiopathic stiffness cohort (16.7% vs 31.0%, P = .01).ConclusionThis study demonstrates that the overall revision surgery outcome of idiopathic stiff TKA is worse than non-idiopathic TKA stiffness. In idiopathic stiffness cohorts, isolated tibial insert exchange was associated with lower re-revision rates than component revision, with similar efficacy in improving ROM, suggesting that isolated tibial insert exchange may be a preferred surgical treatment option in TKA patients with idiopathic stiffness.     

Effect of intraoperative soft tissue balance on postoperative recovery of ambulatory and balancing function in posterior-stabilized total knee arthroplasty

BackgroundThe effectiveness of total knee arthroplasty (TKA) on ambulatory and balancing function recovery should be quantitatively investigated. The present study aimed to evaluate ambulatory function using 3m-timed up and go (TUG) test and balancing function using one-leg standing time (ST) from before and after TKA, and to analyze the effects of intraoperative soft tissue balance on the postoperative improvement of their functions after TKA.MethodsThe study included 65 patients with varus-type knee osteoarthritis who underwent primary posterior-stabilized (PS) TKA. The TUG test and ST were performed preoperatively, 1 month and 12 months after TKA. The intraoperative soft tissue balance, medial and lateral joint looseness (MJL, LJL) were evaluated with both femoral trial in place and patellofemoral joint reduced using the OFR tensor® with the knee at 0, 10, 30, 45, 60, 90, 120, and 135°. The influences of MJL and LJL on the improvement in TUG test time and ST and the 2011 Knee Society Knee Scoring System (2011 KSS) 12 months after TKA were investigated.ResultsThe mean TUG test times and ST were 12.7 and 13.1, 13.5 and 15.4, and 10.9 and 19.2 s preoperatively, 1 month and 12 months after TKA, respectively. The MJL at 10, 30 and 90° flexion was significantly negatively correlated with improvement in the TUG test time and the MJL at 0° flexion was significantly negatively correlated with improvement in the ST. However, the LJL was not significantly correlated with improvement in the TUG test time and the ST. The MJL at 45, 60, and 90° flexion was significantly negatively correlated with the 12-month postoperative score on the activities subscale of the 2011 KSS.ConclusionsThe higher intraoperative medial knee stability may be associated with the better postoperative improvement in ambulatory function and activities subscale of the 2011 KSS after PS-TKA.     

How often is functional range of motion obtained by manipulation for stiff total knee arthroplasty?

Purpose

To evaluate how often manipulation under anesthesia (MUA) can achieve functional flexion ≥ 90 degrees and identify predictor for successful outcome of MUA for stiff total knee arthroplasty (TKA).

Methods

Demographic data, range of motion, and surgical and anesthetic information of 143 MUAs were retrospectively analyzed from 2000 to 2011.

Results

One-hundred thirty-six out of 143 patients (95 %) improved mean range of motion (ROM) from pre-MUA 62 ± 17° to final ROM 101 ± 21° (p < 0.001). Flexion ≥ 90 degrees was achieved in 74% (106/143) of patients. Regional anesthesia was identified as predictor of successful MUA outcome (p = 0.007, OR: 8.5, 95 % CI: 1.2-66.7).

Conclusions

Although the proportion of patients regaining flexion ≥ 90 degrees following MUA was less than those patients with simple overall ROM increase, the functional flexion ≥ 90 degrees was achieved in the vast majority of patients with stiff TKA following MUA.     

The stiff knee: Causes and cures

Stiffness after total knee arthroplasty one of the most common postoperative challenges. Stiffness is currently defined as mild, moderate or severe and is based on loss of flexion or terminal extension. The causes of postoperative stiffness are multifactorial and include poor preoperative range of motion, overly tight flexion or extension gaps, component malrotation, infection, or arthrofibrosis. Treatment can be separated into early or chronic stiffness and is treated with appropriate physical therapy, followed by manipulation under anesthesia which is best performed within 3 months of surgery. For chronic stiffness, arthroscopic lysis of adhesions and MUA is an option, particularly for flexion deficits, or open lysis of adhesions with polyethylene downsizing. Component revision is usually performed after one year from surgery for the severely stiff knee and those with malrotated/malaligned components. For MUA, around 85% of patients will return to normal function and ROM. For the remaining 15%, further surgical intervention can improve ROM by around 15 to 30 degrees. For component revision in the correct patient, ROM can improve significantly but complication, reoperation rates are higher than for aseptic revision surgery. This article reviews the causes and potential cures for stiffness after total knee arthroplasty.     

全膝关节置换的后稳定型假体和保留后交叉韧带疗效比较

目的比较后交叉韧带保留型假体和后稳定型假体在人工全膝关节置换术后早期的临床疗效。 方法选择自2017年1月至2017年6月在上海长海医院接受人工全膝关节置换术的患者，排除患肢有外伤史和手术史的患者，最终纳入74位患者，其中后交叉韧带保留(CR)组35例，后稳定型假体(PS)组39例。分别记录CR组和PS组患者的手术时间、术后引流量、术后3 d血红蛋白浓度，以及术后2周、1年、3年的膝关节活动度(ROM)、最大屈曲角度、西安大略和麦克马斯特大学(WOMAC)评分和美国特种外科医院(HSS)评分。ROM、最大屈曲、HSS、WOMAC在各时间点的比较采用重复测量的方差分析，两组间比较采用独立样本t检验，计数资料组间比较采用卡方检验。 结果CR组的术后引流量明显小于PS组(t＝-16.68，P<0.001)，且术后3 d血红蛋白浓度也明显高于PS组(t＝6.95，P<0.001)。术后2周、1年和3年的随访数据中，CR组的膝关节ROM和最大屈曲度均显著大于PS组，其中术后3年ROM(F＝10.358, P<0.001)，最大屈曲度(F＝10.358, P<0.001)。 结论CR假体和PS假体都可以显著改善患者的膝关节功能，均可作为初次膝关节置换的假体选择。但是在术后早期，CR假体失血量更少，更利于患者术后早期康复。同时与PS假体相比，CR假体在术后早期可能会拥有更好的膝关节活动度和屈曲度。     

Clinical Results after Design Modification of Lospa Total Knee Arthroplasty System: Comparison between Posterior-Stabilized (PS) and PS Plus Types

BackgroundLospa posterior-stabilized (PS) Plus type is a modified version of Lospa PS, in which the polyethylene insert shape is modified to reinforce stability and prevent patella-post impingement compared to Lospa PS. However, studies comparing the clinical and radiographic results of the two designs have not been reported yet. This study aimed to compare the clinical results of total knee arthroplasty (TKA) using the existing PS type and the modified Lospa PS Plus type.MethodsA retrospective study was performed on 558 knees of 342 patients who underwent TKA using the Lospa PS or PS Plus types and were followed up for at least 2 years. Cases were divided into two groups according to the implant used: 212 cases in the PS group and 346 cases in the PS Plus group. For clinical outcome assessment, knee range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Knee Society Score (KSS) were recorded before surgery and at the 2-year follow-up. Radiographic outcomes were evaluated according to the American Knee Society method. The incidence of postoperative complications and survival rates were compared between the two groups.ResultsBoth groups showed significant clinical improvement after surgery. The average KSS significantly improved from 53.4 points in the PS group and 52.3 points in the PS Plus group preoperatively to 91.3 points and 93.2 points after surgery, respectively (p < 0.001). The average WOMAC score improved from 50.4 points in the PS group and 52.3 points in the PS Plus group before surgery to 15.6 points and 14.8 points after surgery, respectively (p < 0.001). There was no significant difference between the two groups in ROM, the alignment of the lower limbs, and the implant position after surgery. The complication rates were also similar between the groups (p = 0.167).ConclusionsThe Lospa PS Plus model is a modified design that improves the post structure from the previous PS type. Compared to the PS type, the PS Plus type showed similar statistical results at 2-year follow-up and good clinical results. The short-term average survival rate was over 98%, showing promising results.     

人工全膝关节置换术治疗膝关节伸直位强直畸形

目的探讨膝关节伸直位强直畸形患者行人工全膝关节置换术的手术要点和术后效果。方法1996年1月至2006年6月,对8例（9膝）膝关节伸直位强直畸形患者行人工全膝关节置换术。术前膝关节活动度均为0°,KSS膝关节评分平均为44分（10～68分）,功能评分平均为17分（-10～55分）。结果8例患者（9膝）围手术期出现的并发症包括髌腱止点撕脱1膝,髌骨下极部分撕脱骨折1膝,术后早期关节血肿1膝,皮肤浅表性感染1膝,经对症治疗后所有患者均治愈出院。术后平均随访40．4个月（7．0～120．0个月）,术后膝关节平均活动度89°（50°～120°）,术后KSS膝关节评分平均为81分（55～93分）,功能评分平均为79分（50～90分）。2例2膝分别存在5°和25°的伸展滞缺。1例1膝因为关节不稳于术后1年行翻修术,更换加厚的胫骨平台垫片。结论膝关节伸直位强直畸形患者行人工全膝关节置换术难度大,并发症发生率较高,但如能恰当处理,仍可以取得较满意的临床效果。术中膝关节的充分暴露,保留足够的髌骨床厚度,保护髌腱和膝关节的血液供应以及正确的软组织平衡技术是手术的关键。     

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.