Gait laboratory analysis of a posterior cruciate-sparing total knee arthroplasty in stair ascent and descent

Successful posterior cruciate ligament-sparing total knee arthroplasty functions in an equivalent fashion to a contralateral normal limb during the mechanical stresses of stair ascent and descent. Motion and force plate analysis reveal highly symmetric gait patterns. Sagittal angles are greater than previously reported for the total condylar prosthesis and are nearly equal to those recorded for the age-matched normal population.     

Temporal-spatial gait adaptations during stair ascent and descent in patients with knee osteoarthritis

Knee osteoarthritis (OA) accounts for more functional disability of the lower extremity than any other disease. We recruited 18 patients with knee OA and 18 healthy age-, height-, mass-, and gender-matched control subjects to investigate the effects knee OA has on select spatial and temporal gait variables during a stair climbing task. No group-by-direction interaction was observed; however, significant effects did occur for group and direction. Specifically, patients with knee OA demonstrated less time in single support, greater time in double support, decreased step length, greater step width, less stride length, decreased total gait velocity, greater total time in support, and less total time in swing, compared with controls. Early-stage knee OA directly influences specific temporal and spatial gait characteristics during stair climbing.     

Preoperative methylprednisolone does not reduce loss of knee-extension strength after total knee arthroplasty

Background and purpose — Patients undergoing total knee arthroplasty (TKA) face challenges related to postoperative reduction in knee-extension strength. We evaluated whether inhibition of the inflammatory response by a single preoperative dose of methylprednisolone (MP) reduces the pronounced loss of knee-extension strength at discharge after fast-track TKA.

Patients and methods — 70 patients undergoing elective unilateral TKA were randomized (1:1) to preoperative intravenous (IV) MP 125?mg (group MP) or isotonic saline IV (group C). All procedures were performed under spinal anesthesia without tourniquet, and with a standardized multimodal analgesic regime. The primary outcome was change in knee-extension strength from baseline to 48?hours postoperatively. Secondary outcomes were knee joint circumference, functional performance using the Timed Up and Go (TUG) test, pain during the aforementioned tests, rescue analgesic requirements, and plasma C-reactive protein (CRP) changes.

Results — 61 patients completed the follow-up. The loss in quadriceps muscle strength was similar between groups; group MP 1.04 (0.22–1.91) Nm/kg (–89%) vs. group C 1.02 (0.22–1.57) Nm/kg (–88%). Also between-group differences were similar for knee circumference, TUG test, and pain scores. MP reduced the inflammatory response (CRP) at 24?hours postoperatively; group MP 33 (IQR 21–50) mg/L vs. group C 72 (IQR 58–92) mg/L (p < 0.001), and 48?hours postoperatively; group MP 83 (IQR 56–125) mg/L vs. group C 192 (IQR 147–265) mg/L (p < 0.001), respectively.

Interpretation — Preoperative systemic administration of MP 125?mg did not reduce the pronounced loss of knee-extension strength or other functional outcomes at discharge after fast-track TKA despite a reduced systemic inflammatory response.     

Preoperative laxity in osteoarthritis patients undergoing total knee arthroplasty

A preoperative quantitative evaluation of soft tissues is helpful for planning total knee arthroplasty, in addition to the conventional clinical examinations involved in moving the knee manually. We evaluated preoperative coronal laxity with osteoarthritis in patients undergoing total knee arthroplasty by applying a force of 150 N with an arthrometer. We examined a consecutive series of 120 knees in 102 patients. The median laxity was 0° in abduction and 8° in adduction. The femorotibial angle on non-weight-bearing standard anteroposterior radiographs was 180° and correlated with both abduction (r = −0.244, p = 0.007) and adduction (r = 0.205, p = 0.025) laxity. The results of a regression analysis suggested that the femorotibial angle is helpful for estimating both laxities. Considering the many reports on how to obtain well-balanced soft tissues, stress radiographs might help to improve the preoperative planning for gaining the optimal laxity deemed appropriate by surgeons.

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Résumé  Une analyse avec évaluation quantitative préopératoire des tissus mous est nécessaire dans la planification d’une prothèse totale de genou, ceci en plus des examens cliniques conventionnels, notamment en ce qui concerne l’évaluation de la mobilité. Nous avons évalué, en préopératoire, les laxités ainsi que les stades de l’arthrose chez les patients qui ont bénéficié d’une prothèse totale du genou. Ces résultats ont été réalisés à l’arthromètre. Nous avons réalisé une série consécutive de 120 genoux chez 102 patients. La laxité moyenne était de 0° en abduction et de 8° en adduction. L’angle fémoro tibial, sans appui, sur les radiographies de face et de profil était de 180° et a été corrélé avec la laxité en abduction (r = −0.244, p = 0.007) et en adduction (r = 0.205, p = 0.025). Les résultats nous montrent que l’angle fémoro tibial est utile pour estimer les laxités. Si l’on considère les différentes études et la meilleure manière d’obtenir une bonne balance ligamentaire, les radiographies en stress permettent d’optimiser le planning opératoire et d’avoir une bonne idée des laxités.

     

Preoperative grip strength measurement and duration of hospital stay in patients undergoing total hip and knee arthroplasty

Purpose

This study explored whether a relationship exists between preoperative pinch and power grip strength, and length of hospital stay in patients undergoing hip and knee arthroplasty at a busy UK hospital. We investigated whether handgrip dynamometry could be used preoperatively to identify patients at greater risk of longer inpatient stays. This would allow focussed intervention preoperatively and facilitate predictors of length of stay postoperatively.

Methods

One hundred and sixty-four patients (64 male, 100 female) undergoing lower limb arthroplasty (83 total knee replacement, 81 total hip replacement) were assessed in pre-admission clinic. Average measurements of pinch grip, power grip and grip endurance were taken from each patient using the Jamar hydraulic dynamometer (Jamar, USA). Duration of inpatient stay of each patient was recorded.

Results

Average duration of hospital stay was 9.4 days. Both average pinch grip strength and average power grip strength had a significant negative correlation with duration of inpatient stay. Those patients with a pinch grip strength less than 6.3 kg remained an inpatient for an average of 2 days longer than those with a pinch grip greater than 6.3 kg.

Conclusions

This simple test may be highly beneficial preoperatively in identifying those patients likely to require longer inpatient stays and therefore those who would benefit from early nutritional intervention and focussed physiotherapy. It may also facilitate predictors of length of stay postoperatively. We believe this may effect significant cost reductions in the NHS.     

Blood transfusion after primary total knee arthroplasty can be significantly minimised through a multimodal blood-loss prevention approach

Purpose

Our aim was to clarify the effective decrease in blood transfusion after primary total knee arthroplasty (TKA) from a multimodal blood-loss prevention approach (MBLPA) and the related risk factors of blood transfusion.

Methods

We retrospectively compared the rate of postoperative blood transfusion in 418 cases of primary TKA during 2010 from a single institution with two different groups of patients, allocating cases to the group with MBLPA (group 1, study group, N = 71) and controls to the group without MBLPA (group 2, standard group, N = 347). MBLPA procedure included pre-operative haemoglobin (Hb) optimisation; femoral canal obturation; limited incision and release; peri- and intra-articular use of saline with adrenalin, morpheic chloride, tobramycin, betamethasone and ropivacaine; tourniquet release after skin closure; 24 hour drain under atmospheric pressure; and two doses of tranexamic acid (TXA) IV. In the control group, surgeons followed the standard procedure without blood-saving techniques. Case–control comparison and blood transfusion risk factors were analysed.

Results

Group 1 had a zero transfusion rate (0/71), whereas 27.4 % of patients (95/347) in group 2 received allogenic blood transfusion. Significant transfusion risk factors were pre-operative Hb <12 g/dl), American Society of Anesthesiologists (ASA) status III and nonobese body mass index (BMI); Age and gender were not significant risk factors.

Conclusions

MBLPA in primary TKA was highly effective, with a zero transfusion rate. Risk factors for transfusion were determined, and eliminating them contributed to the avoidance of allogeneic blood transfusion in our study series.     

In vivo knee kinematics during stair and deep flexion activities in patients with bicruciate substituting total knee arthroplasty

Orthopedic surgeons and their patients continue to seek better functional outcomes after total knee arthroplasty. The bicruciate substituting (BCS) total knee arthroplasty design has been introduced to achieve more natural knee mechanics. The purpose of this study was to characterize kinematics in knees with BCS arthroplasty during deep flexion and stair activities using fluoroscopy and model-image registration. In 20 patients with 25 BCS knees, we observed average implant flexion of 128° during kneeling and consistent posterior condylar translations with knee flexion. Tibial rotations were qualitatively similar to those observed in the arthritic natural knee. Knee kinematics with BCS arthroplasty were qualitatively more similar to arthritic natural knees than knees with either posterior cruciate-retaining or posterior-stabilized arthroplasty.     

Kneeling ability after total knee arthroplasty. Perception and reality.

Kneeling as one of the knee's capabilities required for many activities of daily living has not been examined in detail after total knee replacement. The purpose of the present study was to question the patients' ability to kneel and their perception of factors affecting this ability after total knee arthroplasty, and to objectively assess their kneeling ability. Seventy patients with 100 total knee arthroplasties were asked to comment on their ability to kneel. Thirty-one patients with 44 knees said they could kneel easily, 29 patients with 41 knees said they were able to kneel but avoided doing so, and 10 patients with 15 knees said they were unable to kneel. Regarding observed kneeling ability, all patients were able to kneel under supervision: 56 patients with 82 knees knelt easily and got up easily from this position, 11 patients with 14 knees showed slight difficulties in kneeling or in getting up, and three patients with four knees had marked difficulties with kneeling. The patients' perceived ability to kneel after total knee arthroplasty was less than their observed ability. Fear of harming the prosthesis and lack of information prevented kneeling in 49% of the patients (27 of 56 knees) with perceived inability to kneel. Of those patients with observed difficulty in kneeling, scar pain and back related problems seemed to be major factors in limiting the kneeling ability. Kneeling, as an important function of the knee, should be given additional consideration in relation to the functional results of total knee arthroplasty. Patients should be counseled regarding factors affecting future ability to kneel.     

术前血沉值对女性骨关节炎患者人工膝关节置换术围手术期输血的影响

目的研究女性骨关节炎患者行初次人工膝关节置换术中围手术期输血量和输血需求相关的临床因素。方法回顾性分析符合本组严格病例筛选标准的59例女性膝关节骨关节炎患者的病历资料,这些患者均为接受初次人工膝关节表面置换术（共71个膝关节）。评估患者年龄、高血压病史、手术麻醉方式、手术时间、假体厂家、术前血红蛋白值及血沉值等临床因素对围手术期出血量以及输血量的影响。结果术前血沉值异常患者较血沉值正常患者围手术期的输血量更大（Z=-2．015,P〈0．05）,血沉值对输血量的影响有统计学意义（P〈0．05）;血沉值与围手术期输血量呈正相关（r=0．347,P〈0．01）。在年龄1〉65岁患者中,术前血沉值异常患者围手术期输血量比血沉值正常患者明显增多（Z=-2．915,P〈0．01）,血沉值（P〈0．01）与血红蛋白值（P〈0．05）对输血量的影响有统计学意义;血沉值与输血量的正性相关有高度显著性（r=0．489,P〈0．01）。结论对于女性骨关节炎患者,术前血沉值可能是预测人工膝关节置换术围手术期输血量的指标之一。     

The effects of early rollback in total knee arthroplasty on stair stepping

We investigated the effects of early compared with late (ie, in flexion) rollback on quadriceps efficiency during stair stepping. We studied 10 patients with the IB II (Zimmer, Warsaw, IN) total knee arthroplasty (TKA), designed to enforce rollback at 73 degrees of knee flexion; 9 patients with the Maxim PS (Biomet, Inc, Warsaw, IN) TKA, designed to enforce rollback between 20 degrees and 30 degrees of flexion; 8 patients with the TRAC PS (Biomet, Inc, Warsaw, IN) mobile bearing TKA, designed to enforce rollback at 8 degrees of flexion; and 21 healthy control subjects during stair stepping. We measured the external knee flexion moments, which must be largely balanced by quadriceps force acting over the quadriceps lever arm, as indicators of quadriceps efficiency. The peak external knee flexion moment generated by the IB II patients during stair stepping was 12.4% and occurred at 65 degrees of knee flexion. This moment was significantly less (P=.006) than the peak moment, 17.6%, generated by the healthy controls. Knee flexion for the IB II patients did not reach 73 degrees, and rollback was not enforced until after the peak moment (ie, maximum demands on the quadriceps) had been attained. The peak moments generated by the TRAC PS patients, 14.2%, and Maxim patients, 14.8%, were not significantly different from that of the controls. These results suggest that early as compared with late rollback returns more normal quadriceps efficiency during stair stepping.     

早期本体感觉训练对全膝关节置换术后患者步行能力的影响

[目的]观察本体感觉训练对全膝关节置换术后患者步行能力的影响。[方法]将40例全膝关节置换术后第3周的患者随机分为对照组及治疗组,对照组进行常规康复训练,治疗组在常规康复训练的基础上,增加本体感觉训练,包括闭链运动训练及Mtd视觉及听觉的反馈平衡训练,并于术后第3周、第4周末及第6周末进行起立-行走计时测试(timed"up and go"test,TUGT)、膝关节百分评分系统(the hospital for special surgery,HSS)及Berg平衡量表(Berg balance scale,BBS)评测。计数资料采用t检验,计量资料采用u检验。[结果]本体感觉训练前,两组患者的上述评测结果比较差异无显著性意义(P>0.05),而在本体感觉训练后,尤其在术后第6周末,治疗组评测结果有明显改善,组间、组内比较差异有统计学意义(P<0.05)。[结论]早期本体感觉训练可有效地改善患者的躯干、膝关节的动静态平衡能力,恢复患膝运动功能,提高独立步行能力。     

Preoperative risk factors for deep vein thrombosis in knee osteoarthritis patients undergoing total knee arthroplasty

BackgroundTo analyze the risk factors for preoperative deep vein thrombosis (DVT) in knee osteoarthritis (OA) patients undergoing total knee arthroplasty (TKA).MethodsIn this retrospective study, a total of 584 knee OA patients undergoing TKA were enrolled. General information, medical records and preoperative laboratory examination results of the patients were collected. According to the results of Doppler ultrasonography for the lower extremities, the patients were divided into DVT group and non-DVT group. Univariate and multivariate logistic regression were used to identify independent risk factors for preoperative DVT in knee OA patients undergoing TKA.ResultsThe incidence of DVT before TKA was 6.85% (40 cases). The increase of ESR (Erythrocyte Sedimentation Rate), platelet crit, IL-6 (Interleukin-6), and PCT (Procalcitonin) were associated with the development of DVT before TKA. Factors as coronary heart disease (CHD), diabetes mellitus (DM), Chronic Kidney Disease (CKD), NLR (ratio of neutrophils to lymphocytes), lower limb venous blood stasis, the time from onset to admission, RBC, PLT were identified by multivariate logistic regression to be the independent risk factors for preoperative DVT in knee OA patients undergoing TKA.ConclusionsDM, CKD, CHD, increased in ESR, IL-6 and PCT, blood stasis of the lower extremities, increased in PLT, platelet crit and the time from onset to admission, decreased in RBC, were high risk factors for preoperative DVT in knee OA patients undergoing TKA.     

Functional Outcomes in High-function-demand patients after total knee arthroplasty

Total knee arthroplasty is a safe last-resort treatment for osteoarthritis that has excellent results in low-function-demand elderly patients. Current implants offer the same results in high-function-demand patients. However, supportive data do not exist.One-year Krackow Activity Scores (KAS) of 552 patients from 2 prospective studies were used to retrospectively determine low- and high-function-demand populations. Low function demand was defined as a KAS between 1 and 9 points, and high function demand was defined as a KAS between 10 and 18 points. Patients were assessed preoperatively and at 6 weeks, 3 months, and 1 and 2 years postoperatively per the Knee Society Score-function domain, KAS, SF-36, range of motion, and pain. Comparability between groups was tested for demographics and comorbidities.Both groups showed significant improvement in function, range of motion, and pain 2 years postoperatively. High-function-demand patients had comparable improvement in function compared with low-function-demand patients. Excellent function can be achieved in high-function-demand patients.     

Results of contralateral total knee arthroplasty in patients with a history of stiff total knee arthroplasty

This study seeks to evaluate the clinical outcomes of a second primary total knee arthroplasty in patients whose initial (contralateral) primary total knee arthroplasty was complicated by stiffness. We retrospectively compared the preoperative and postoperative range of motion and Knee Society Scores from a study group of 15 patients with an age-matched control group. Statistical analysis did not reveal a significant difference in final postoperative range of motion or Knee Society Scores between the 2 groups. However, there was a statistically significant higher rate of closed manipulation in the study group. Therefore, although the study group did show a higher rate of early stiffness, eventual functional outcome was comparable with a nonstiffness control group.     

肥胖患者膝关节表面置换术后的早期康复

目的探讨肥胖患者初次膝关节置换术后早期康复的方法。方法自2009年1月至2012年6月共完成肥胖患者初次膝关节置换42例42膝,男8例,女34例;年龄60～78岁,平均65岁,身体质量指数（BMI）33—52,平均46。术后早期进行持续被动关节运动增加关节活动度（ROM）和进行股四头肌及胭绳肌肌力的强化训练,延长住院时间至术后14d。分别以术前2d、术后2d、1、2、4、8、12、24周作为观察点,使用VAS疼痛评分、WOMAC评分和ROM对膝关节功能及疼痛程度进行评价。结果术后VAS疼痛评分、WOMAC评分低于术前,术后ROM高于术前,差异均有统计学意义。所有指标在术后4周以后均有逐步改善,但差异没有统计学意义。结论肥胖患者膝关节置换术后早期行功能锻炼及适当延长住院时间可以提高膝关节功能。     

全膝关节置换患者术前结果期望及影响因素研究

目的调查全膝关节置换术患者术前结果期望现状,并分析其影响因素。方法采用骨关节炎指数量表及特殊手术医院-全膝关节置换期望调查工具对198例拟行全膝关节置换术的患者进行调查。结果患者术前结果期望平均分为89.17±13.89。回归分析结果显示,患者年龄、居住同伴、术前关节功能活动评分等级是术前结果期望水平的影响因素(均P0.01)。结论全膝关节置换患者术前结果期望处于较高水平。需加强患者术前期望评估及管理,以提高患者满意度、改善医患关系。     

Preoperative identification of a bone-cement allergy in a patient undergoing total knee arthroplasty

Allergy to polymethyl methacrylate bone-cement or its components is unusual. Because of the potential for an inflammatory response in an allergic patient and the possibility of pain and loosening if a cemented implant is used, it is imperative to identify patients with this allergy to modify their treatment. We report the case of an otherwise healthy 60-year-old woman who needed a total knee arthroplasty and who had an allergy to methyl methacrylate bone-cement identified preoperatively. The appropriate evaluation for a patient who is suspected to have an allergy to bone-cement or its components is reviewed.     

Changes in muscle torque in patients after total knee arthroplasty

AIM: The purpose of this study was to compare muscle torque during isokinetic knee movements of patients after total knee arthroplasty (TKA) with a similar healthy group. METHOD: 43 patients were examined 3 years after primary total knee arthroplasty with an isokinetic dynamometer (Cybex 340). Torque measurements were evaluated for extension and flexion with 4 different velocities. The results were compared with a group of 43 people without knee disease. Bouth groups consist of 29 women and 14 men. The mean age was also comparable (66.4 vs. 65.8 years). RESULTS: A mean peak torque of 65.9 Nm was measured during extension with low velocity (60 degrees /s) in the group of patients with TKA -- 84.3 % of the control group (p = 0.079). At the highest velocity the patients produced 30.2 Nm. This was 72.8 % of the control group (difference statistically significant, p = 0.006). No differences were found in the Extension/Flexion ratio between the two groups. CONCLUSION: The deficites of knee strength in patients after TKA are more distinct in high velocities of motion.     

Knee strength,power and stair performance of the elderly 5 years after unicompartmental knee arthroplasty

European Journal of Orthopaedic Surgery & Traumatology - Unicompartmental knee arthroplasty (UKA) has been shown to demonstrate some satisfactory short-term outcomes. However, to our knowledge,...