Effect of gap balancing and measured resection techniques on implant migration and contact kinematics of a cementless total knee arthroplasty

BackgroundThe purpose of this study was to compare implant migration and tibiofemoral contact kinematics of a cementless primary total knee arthroplasty (TKA) implanted using either a gap balancing (GB) or measured resection (MR) surgical technique.MethodsThirty-nine patients underwent TKA via a GB (n = 19) or a MR (n = 20) surgical technique. Patients received an identical fixed-bearing, cruciate-retaining cementless implant. Patients underwent a baseline radiostereometric analysis (RSA) exam at two weeks post-operation, with follow-up visits at six weeks, three months, six months, and one year post-operation. Migration including maximum total point motion (MTPM) of the femoral and tibial components was calculated over time. At the one year visit patients also underwent a kinematic exam via RSA.ResultsMean MTPM of the tibial component at one year post-operation was not different (mean difference = 0.09 mm, p = 0.980) between the GB group (0.85 ± 0.37 mm) and the MR group (0.94 ± 0.41 mm). Femoral component MTPM at one year post-operation was also not different (mean difference = 0.27 mm, p = 0.463) between the GB group (0.62 ± 0.34 mm) and the MR group (0.89 ± 0.44 mm). Both groups displayed similar kinematic patterns.ConclusionsThere was no difference in implant migration and kinematics of a single-radius, cruciate retaining cementless TKA performed using a GB or MR surgical technique. The magnitude of migration suggests there is low risk of early loosening. The results provide support for using the cementless implant with either a GB or MR technique.     

Bone bridge fixation has superior biomechanics on posterior knees to bone plug fixation after lateral meniscal allograft transplantation – A biomechanical study simulating partial weight-bearing conditions

BackgroundIt remains unknown how biomechanics change in posterior lateral knee using different fixation techniques in lateral meniscal allograft transplantation (MAT) during simulated toe-touch partial weight-bearing. This study aimed to compare the biomechanical effects on posterior knee between bridge and bone plug fixation in lateral MAT.MethodsIntact knee, bone bridge fixation, and bone plug fixation were tested with 500 N of axial load during knee flexion at 0°, 30°, and 60°, which simulated toe-touch partial weight-bearing. Contact area and peak pressure were assessed on posterior knee and the shift of peak pressure position were measured.ResultsOn the posterior lateral compartment, the contact mechanics of bone bridge fixation were similar to those of the intact knee (all P-values > 0.05), but its peak pressure was higher than that of intact knee at 60° (P = 0.002). For bone plug fixation, the contact area of the posterior lateral knee was significantly lower than those of intact knee and bone bridge fixation at 30° and 60° (all P-values < 0.05). The peak pressure of the posterior lateral knee was higher than that of the intact knee at all flexions and higher than that of bone bridge fixation at 30° and 60° (all P-values < 0.05). The peak pressure position of bone plug fixation shifted more laterally and posteriorly compared with intact knee and bone bridge fixation during knee flexion.ConclusionBone bridges could maintain posterior knee biomechanics better than bone plug fixation during knee bending during partial weight-bearing.     

Do the distal femur and the proximal tibia have narrower aspect ratios in smaller knees? : A morphological analysis of osteoarthritic knees in the Japanese population using computed tomography

BackgroundWhether the distal femur and the proximal tibia have narrower aspect ratios in smaller knees has not been clarified. The purpose of this study was to confirm the dimensional characteristics of the distal femur and the proximal tibia using a novel method for consistently determining knee size.MethodsA total of 220 Japanese osteoarthritic knees (160 female and 60 male knees) were analyzed using computed tomography. The mediolateral (ML) and the anteroposterior (AP) dimensions of the distal femur (fML, fAP) and the proximal tibia (tML, tAP) were measured. The aspect ratios (ML/AP) of the distal femur (fML/fAP) and the proximal tibia (tML/tAP) were assessed against the product of AP × ML as a consistent determination of knee size.ResultsThe fML/fAP ratios positively correlated with knee size (fAP × fML) (r = 0.420, p < 0.001), only in the combined cohort, attributable to the narrower aspect ratios of female knees. No correlations were found between the tML/tAP ratios and knee size (tAP × tML) among females, males, nor all subjects (p = 0.299, 0.994, and 0.996, respectively). Aspect ratio correlations to knee size diverged between the three knee size indices, AP, ML, and AP × ML.ConclusionsAP × ML was the meaningful option for knee size indexing in our morphological analyses. The distal femur, but not the proximal tibia, was found to have a narrower aspect ratio in female knees in the Japanese population.     

The patient perspective,experience and satisfaction of day case unicompartmental knee arthroplasty: A short-term mixed-methods study

BackgroundDay case unicompartmental knee arthroplasty (UKA) is increasingly being performed worldwide. When performed in the appropriate patient, day case UKA has been demonstrated to be safe, cost effective and improve resource allocation. Limited evidence highlights increased patient satisfaction of day case UKA when compared with inpatient UKA. A detailed study of the patient perspective, experience and satisfaction following day case UKA has not been described before.MethodsA retrospective case series review of 21 consecutive patients (19 unilateral, 2 bilateral) undergoing day case UKA in an elective orthopaedic centre was undertaken. A qualitative and quantitative patient assessment of the day case UKA experience was administered. A five-point Likert scale satisfaction questionnaire, Oxford Knee Score (OKS) and open-ended interview was undertaken. The qualitative responses underwent thematic analysis.ResultsOne hundred percent of patients expressed satisfaction (76.2% completely satisfied, 33.8% moderately satisfied) with day case UKA. The majority of patients (90.5%) reported that if they had to undergo UKA again they would prefer a day case over an inpatient procedure. Patients consider surgical outcome, physiotherapy provision, discharge planning, postoperative medications and follow up as key aspects of day case UKA care. One patient was re-admitted following discharge.ConclusionsThe present study demonstrates a high level of patient satisfaction with day case UKA. The results reported herein are subject to the study limitations of sample size, recall bias and inclusion criteria. We recommend that the themes identified by patients are addressed through a multidisciplinary approach with well-defined clinical pathways for a high-quality patient-centred experience.     

Effectiveness,Patient Satisfaction,and Cost Reduction of Virtual Joint Replacement Clinic Follow-Up of Hip and Knee Arthroplasty

BackgroundTotal hip and knee arthroplasties are increasingly performed operations, and routine follow-up places huge demands on orthopedic services. This study investigates the effectiveness, patients’ satisfaction, and cost reduction of Virtual Joint Replacement Clinic (VJRC) follow-up of total hip arthroplasty and total knee arthroplasty patients in a university hospital. VJRC is especially valuable when in-person appointments are not advised or feasible such as during the COVID-19 pandemic.MethodsA total of 1749 patients who were invited for VJRC follow-up for knee or hip arthroplasty from January 2017 to December 2018 were included in this retrospective study. Patients were referred to VJRC after their 6-week postoperative review. Routine VJRC postoperative review was undertaken at 1 and 7 years and then 3-yearly thereafter. We evaluated the VJRC patient response rate, acceptability, and outcome. Patient satisfaction was measured in a subgroup of patients using a satisfaction survey. VJRC costs were calculated compared to face-to-face follow-up.ResultsThe VJRC had a 92.05% overall response rate. Only 7.22% required further in-person appointments with only 3% being reviewed by an orthopedic consultant. VJRC resulted in an estimated saving of £42,644 per year at our institution. The patients’ satisfaction survey showed that 89.29% of the patients were either satisfied or very satisfied with VJRC follow-up.ConclusionVJRC follow-up for hip and knee arthroplasty patients is an effective alternative to in-person clinic assessment which is accepted by patients, has high patient satisfaction, and can reduce the cost to both health services and patients.     

Aseptic complications of total knee replacement and treatment options

Total knee replacement surgery is a commonly performed procedure with good improvement in the quality of life for patients. However, there are a number of complications from surgery than can have adverse outcomes for patients. Although infection is a disastrous complication of orthopaedic surgery, aseptic complications occur more commonly. We also aim to review these complications and give the principles and strategies for preventing and treating them. This article discusses early perioperative problems such as acute nerve and vessel injuries, thromboembolism, wound problems and extensor mechanism problems. It also reviews the pertinent points of later postoperative complications such as persistent swelling, pain, loosening and stability problems.     

从“筋骨、痹痿、虚实、动静、刚柔”谈膝骨关节炎功能障碍的特点

膝骨关节炎(KOA)属于进展性骨关节病,其功能障碍主要表现为膝关节疼痛、僵硬、屈伸行走不利或受限,以及关节失稳、运动控制下降和本体感觉低下等。我国KOA患者众多,且还在逐年增加,引起的功能障碍严重影响着患者健康与生活质量,因此对其开展康复的研究与实践至关重要。中医康复着眼于功能,注重辨证康复,是我国康复医学的固有特色及优势。前期的研究基于KOA功能障碍的中医证候表现,本研究经大量文献梳理及多年临床实践,从“筋骨、痹痿、虚实、动静、刚柔”5个角度为切入点,提出KOA功能障碍具有“筋骨同病、痹痿并见、虚实错杂、动静失衡、刚柔失常”5个基本特点。鉴于KOA功能障碍具有早、中、晚三期的阶段性特点,在该病发生发展的不同阶段,其功能障碍在“筋骨、痹痿、虚实、动静、刚柔”之间的表现又各有所侧重。本研究从“筋骨同病、痹痿并见、虚实错杂、动静失衡、刚柔失常”5个方面分别阐释了KOA功能障碍的特点:“筋骨同病”侧重于病位,是KOA所致功能障碍的基本病机特征,贯穿于其发病的始终;“痹痿并见、虚实错杂”偏重病性,是KOA功能障碍的基本特点;“动静失衡”偏重病因,是引起KOA病情反复及加重的重要因素;“刚柔失常”则是兼具病状与病因,是膝关节失去“骨正筋柔”的表现方式,也是KOA功能障碍的重要特征。本研究旨在进一步完善KOA的中医康复理论,为其康复治疗提供参考。     

Individual analysis of dynamic stability for twenty-four Tai Chi forms among persons with knee osteoarthritis: A pilot study

BackgroundTai Chi (TC) training has been increasingly used to prevent falls. However, the underlying biomechanical mechanisms of TC training which influence fall risk remain unknown. As a result, the selection of TC forms differs among studies, leading to inconsistent results.Research questionIs dynamic stability different between the simplified 24 Yang-style TC forms among adults with knee osteoarthritis?MethodsTen participants with mild to moderate knee osteoarthritis were recruited. Under one-on-one instruction by an experienced TC master, each participant learned how to correctly perform the 24-form TC movements. Participants’ full-body kinematic and kinetic data was collected during walking trials and performance of the respective TC forms. Their dynamic stability was calculated in both sagittal and frontal planes and compared between each TC form and regular walking.ResultsThe results indicate that dynamic stability in both planes significantly varies among forms. Moreover, some forms pose a greater challenge to dynamic stability in comparison to others. The most challenging TC forms are Form 8 for stability in the sagittal plane and Form 10 in the frontal plane. Among all forms, Form 1 appears to be the least challenging.SignificanceOur findings could provide foundational information to identify the best TC forms for optimizing the effectiveness of TC-based fall prevention interventions.     

Longer Operative Time Results in a Higher Rate of Subsequent Periprosthetic Joint Infection in Patients Undergoing Primary Joint Arthroplasty

Background

Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA.