Introduction

Material and methods

Results

Discussion

Conclusions

References

Abstract

Background: Dynamic tibial tray sensors are playing an increasing role in total knee arthroplasty (TKA) coronal balancing. Sensor balance is proposed to lead to improved patient outcomes compared with sensor-unbalanced TKA, and traditional manual-balanced TKA. However, the “learning curve” of this technology is not known, and also whether sensor use can improve manual TKA balance skills once the sensor is taken away, effectively “training” the surgeon.
Methods: We conducted a single-surgeon prospective study on 104 consecutive TKAs. In Nonblinded Phase I (n ¼ 49), sensor-directed releases were performed during trialing and final intercompartmental load was recorded. In Blinded Phase II (n ¼ 55), manual-balanced TKA was performed and final sensor readings were recorded by a blinded observer after cementation. We used cumulative summation analysis and sequential probability ratio testing to analyze the surgeon learning curve in both phases. Results: In Nonblinded Phase I, sensor balance proficiency was attained most easily at 10, followed by 90, and most difficult to attain at 45 of flexion. In Blinded Phase II, manual balance was lost most quickly at 45, followed by 90, and preserved for longest at 10 of flexion. The number of cases in the steady state periods (early phase periods where there is a mix of sensor balance and sensor imbalance) for both phases is similar.
Conclusions: A surgeon who consistently uses the dynamic sensor demonstrates a learning curve with its use, and an “attrition” curve once it is removed. Consistent sensor balance is more predictable with constant sensor use.

Introduction

Recent studies suggest that a balanced total knee arthroplasty (TKA) may lead to better functional outcomes and patient satisfaction [1-5]. Manual coronal plane balance has been achieved primarily through tactile feedback and visual cues. Whether a knee is “balanced” is subjective and is affected by various factors including surgeon training, experience, and surgical volume [6,7]. Furthermore, unlike joint alignment, cut angles, and magnitude of component rotation, there has not been a widely accepted metric for “balance.” Asymmetric radiographic joint space gapping is but one sign of gross extension space coronal imbalance. There are as yet no comparable markers for finer magnitudes of imbalance and imbalance at varying degrees of flexion. In recent years, dynamic sensors have played an increasing role in coronal plane balancing. These sensors display tibiofemoral contact points and measure load (or force) to provide real-time intraoperative feedback on whether the knee is truly “sensorbalanced”. Various authors suggest that sensor-balanced TKA may lead to improved patient satisfaction and patient-reported outcomes [1-5], improved survivorship, and a reduced need for revision [8].

1- Introduction

2- Methods

3- Results

4- Discussion

References

Abstract

Background
A source of myofascial pain and myofascial trigger points (MTrPs) in muscles of the knee area could play a crucial role in the management of pain in osteoarthritis patients. The aim of this study was to describe and compare demographic, clinical and myofascial pain syndrome characteristics in older adults with knee osteoarthritis by sex and age distribution.
Methods
A cross-sectional study was carried out. 114 patients with osteoarthritis were recruited in older-adult care centers. The diagnosis of active and/or latent MTrPs (AMTrPs/LMTrPs) was performed. Numerical Pain Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Barthel Index, Timed Up and Go Test (TUG), Mini-Mental State Examination, EuroQol Group 5-Dimension Self-Report Questionnaire, chronicity, number of falls, and medication use were collected. All data were compared by sex (male or female) and age (< 70, 70–80, or > 80 years) distributions.
Results
The most prevalent muscles with AMTrPs and LMTrPs were the quadriceps vastus medialis (75.43%) and lateralis (65.78%), respectively. The clinical characteristics showed significant differences (P<0.05) for chronicity, WOMAC functionality and total scores, TUG, falls rate and medication between males and females, as well as for chronicity, Barthel index and TUG between age distributions. There were not any significant differences (P>0.05) by sex or age distribution according to the number and presence of active and latent MTrPs.
Conclusions
The demographic and clinical features of older adults with knee osteoarthritis may be influenced by sex and age distribution. Nevertheless, the myofascial pain syndrome associated with knee osteoarthritis did not seem to be related to sex or age distribution.

Introduction

Osteoarthritis (OA) is one of the main reasons for disability within the elderly population; it has a high prevalence in society in general [1,2]. The knee is the most frequently affected joint among those associated with OA, and often results in disability [3,4]. OA of the knee is a syndrome distinguished by the presence of pain, and often corresponds with radiological and laboratory findings [5]. However, the real pathogenesis is still poorly understood. Many studies have shown a disparity between the pain description and the results from x-ray imaging [6–8]. OA has an estimated prevalence of seven million population within the United States [9]. More than in any other joint, OA of the knee causes a large number of the clinical symptoms that lead to impairment [10–12]. The estimated prevalence of OA in Spain is 46% for women and 21% for men over the age of 45 years of age [13]; OA of the knee represents 10% of this [14]. In this same country, knee OA had an economic impact of 4700 million euros only in 2014, an amount comparable to 0.5% of the Gross Domestic Product in that same year. In conclusion, we can state that this. This syndrome has become a major health issue in every country [15]. Although the etiology of knee OA remains undefined, it is known that its incidence increases with age [16,17]. In addition, being overweight becomes a risk factor for the development and progression of this syndrome and it can even be related to joint replacement [18–20]. One of the latest critical reviews found that a source of myofascial pain in knee OA and the existence of myofascial trigger points (MTrPs) in muscles of the knee area could play a crucial role in pain and impairment in patients with OA [21]. In fact, considering that MTrPs are known to be tender spots within a taut band of voluntary muscles that can produce signs and symptoms related to the sensitive, motor or autonomic component, their prevalence may reach 100% in patients with OA knee, specifically in the internal gastrocnemius [92%] and vastus medialis muscles [67%] [22]. Although these muscles have active myofascial trigger points (AMTrPs) that produce spontaneous and recognized pain, latent myofascial trigger points (LMTrPs) may play a role in limiting range of motion, altering muscle contraction patterns, and generating local or referred pain when manual pressure is applied [23,24].

Abstract

Objective: To investigate whether the number of hyaluronic acid (HA) injections in a sodium hyaluronate (Hyalgan) course of therapy alters effectiveness in reducing knee osteoarthritis (OA) pain. Data Sources: Electronic databases, including PubMed and Embase, were searched from January 1980 until November 2015.

Study Selection: We included clinical studies that evaluated the effectiveness of a course of 3 or 5 weekly intra-articular injections of Hyalgan to treat knee OA pain. We also included clinical studies evaluating the effectiveness of a 3-week course of other Food and Drug Administrationeapproved HA treatments of knee OA pain. Twenty-four studies were identified, comprising 2168 study participants in 30 treated cohorts.

Data Extraction: We determined effect sizes for selected studies by extracting knee OA pain scores before and after HA or control treatments. Meta-regressions were implemented to determine whether the number of weekly injections in a course of Hyalgan therapy modified outcomes.

Hyaluronic acid (HA) is a glycosaminoglycan found within the extracellular matrix of various soft connective tissues and epithelial and neural tissues. This polysaccharide is a natural biopolymer consisting of repeating units of the disaccharide N-acetylglucosamine and sodium glucuronate. The rheologic properties of HA, transitioning between viscous and elastic behavior, play an important role in its ability to protect articular joints from the shear forces of rapid motion. An essential component of synovial fluid in the knee joint, HA enables the fluid to act as a lubricant and shock absorber. Osteoarthritis (OA) is characterized by both a loss of articular cartilage and a reduction in the viscoelastic properties of synovial

Abstract

This paper reports on a powered prosthetic knee joint powered by artificial muscles. A musculoskeletal system integrating artificial and biological muscles was simulated. The gait cycle was divided into seven modes. Based on the results of the simulation, the artificial muscles were pressurized to provide the biological knee torque. Analysis of the gait trials of an amputee showed the timing of artificial muscles was similar to EMG of biological knee muscles. This paper is an initial step forward to implement the concept of biomimetic approach in prosthetic knee technology.

Introduction

A major source of disability among the patients who have lost their limb is the lower extremity amputation, and specifically, transfemoral amputation. Approximately, 1.9 million people are affected by limb loss, and 400,000 of them have above the knee amputation [1]. Due to important role of prosthetic knee in transfemoral ambulation, its design and function are particularly important [2]. One of the deficiencies of current prosthetic knees that prevent them from achieving this control is their inability to introduce new energy into locomotion. As a result, they cannot emulate certain functionalities of biological knee in situations like level ground walking, sit to stand maneuver, and stair/slope accent [3].