Focusing osteoarthritis management on modifiable risk factors and future therapeutic prospects

Do age, gender, BMI and disease duration influence the clinical outcomes in patients of knee osteoarthritis treated with serial injections of autologous platelet rich plasma?

Purpose

To study whether age, gender, body mass index(BMI) and disease duration influence the clinical outcomes in kellgren-Lawrence(K-L) grade II,III knee osteoarthritis(KOA) patients treated with serial injections of platelet rich plasma(PRP).

Patients and methods

65 patients were given three monthly intra-articular injections of PRP in this prospective interventional study. The patients were divided into subgroups depending on the factor studied: by age(in years) into young <45(n = 7), middle age 45-60(n = 35), and elderly >60(n = 23): by BMI(in kg/m2) into; normal <25(n = 25), overweight 25-30(n = 27) and obese >30(n = 13) and disease duration; less(n = 32) or more than 1 year(n = 33) symptom duration. Visual analogue scale (VAS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used as outcome measures and assessed before each injection and then at 6 and 9 months post injection. Groups were homogenous with respect to baseline characteristics.

Results

Mean VAS and WOMAC scores showed a statistically significant improvement (P < 0.0001) across all groups and subgroups (age,gender,BMI,disease duration) at follow up. On intra-subgroup comparison, we found no significant differences(P > 0.05) among age, BMI or gender subgroups, however the scores were significantly better in patients with disease duration of less than 1 year than those with more than 1 year duration at both 6 and 9 months[P < 0.001(RC = 9.630,95% CI = 4.037-15.222,P = 0.001)].

Conclusion

PRP injections if given serially can improve the short term subjective scores of VAS and WOMAC scores in patients with K-L grade II and III KOA irrespective of age, gender, BMI or disease duration, however, clinical benefits can be maximized if given early in the disease course.

Targeted exercises can improve biomechanical markers in individuals with knee osteoarthritis: A secondary analysis from a cluster randomized controlled trial

BACKGROUND

It is not clear whether exercise therapy significantly improves knee biomechanics during gait in osteoarthritis (OA) patients. This study aimed to determine whether targeted exercises based on a knee kinesiography exam improve biomechanical markers (BMs) compared with conventional primary care (CPC) management.

METHODS

This was a secondary analysis of a cluster randomized controlled trial in which patients were assigned to one of three groups: (1) Control (CPC), (2) Exercise, and (3) Exercise&Education. Fourteen known BMs in knee OA patients were assessed. The primary outcome was the global evolution ratio (GER), which was calculated as the sum of improved BMs over the sum of deteriorated BMs 6 months after baseline assessment. GER scores were categorized with three different sets of cut-off values into clinical levels: (a) Deteriorated, (b) Stabilized, and (c) Improved. Ordinal logistic regressions were performed on the per-protocol population to determine whether there was a relationship between group assignment and GER levels.

RESULTS

Of the 221 eligible participants, 163 were included. Two different regression models showed that patients from Group 3 (Exercise&Education) were 2.5-times more likely to be in an upper GER level (i.e., Stabilized or Improved) than patients from the control group (both odds ratio (OR) > 2.46, Wald Χ²(1) ≥ 7.268, P ≤ 0.01). They also reported significantly more improvement in pain and function (Knee Injury and Osteoarthritis Outcome Score, both P ≤ 0.01).

CONCLUSIONS

Results suggest that targeted exercises can improve biomechanical markers in knee OA patients compared with CPC treatment. Further studies are needed to confirm these findings and refine the biomechanical markers to address to maximize patients' clinical outcomes.

Early improvement in physical activity and function after total hip arthroplasty: Predictors of outcomes

Objectives

This study aims to assess early changes in physical activity and function after total hip arthroplasty (THA) using both subjective and objective methods, and to identify predictors of outcomes of THA.

Patients and methods

Between October 2014 and October 2015, a total of 50 patients (14 males, 36 females; mean age 57.1±13.0 years; range, 31 to 75 years) with end-stage primary hip osteoarthritis who were scheduled for THA and 50 age- and sex-matched controls (10 males, 40 females; mean age 52.9±9.3 years; range, 36 to 75 years) were included in the study. Pain was evaluated using the Numeric Rating Scale (NRS), physical function using the Lequesne Index, physical capacity using the Six-Minute Walking Test (6MWT), and physical activity using both International Physical Activity Impact Questionnaire Short Form (IPAQ-SF) and step count monitor. Data at baseline and six weeks and six months were recorded.

Results

Pain severity was significantly lower after THA at six weeks and six months (NRS scores: 2.83 and 0.82, respectively; p<0.001), compared to baseline. Physical function, capacity, and activity significantly improved after THA at six weeks and six months with a mean Lequesne Index score of 2.62 and 1.02, respectively. The mean 6MWT distance was 272.62 at six weeks and 326.16 at six months. The mean IPAQ and 6MWT results were similar between the patient and control groups at six weeks and six months. Age, presence of comorbidities, and baseline Lequesne Index score were found to be effective on functional outcomes of THA. Age and baseline 6MWT scores were correlated with physical capacity after THA.

Conclusion

Our study showed a significant early improvement in pain severity and physical activity and function at six weeks and six months after THA, compared to baseline values. Baseline values and age were the positive predictors of improved postoperative function and physical capacity.

Pattern Classification by the Hotelling Statistic and Application to Knee Osteoarthritis Kinematic Signals

The analysis of knee kinematic data, which come in the form of a small sample of discrete curves that describe repeated measurements of the temporal variation of each of the knee three fundamental angles of rotation during a subject walking cycle, can inform knee pathology classification because, in general, different pathologies have different kinematic data patterns. However, high data dimensionality and the scarcity of reference data, which characterize this type of application, challenge classification and make it prone to error, a problem Duda and Hart refer to as the curse of dimensionality. The purpose of this study is to investigate a sample-based classifier which evaluates data proximity by the two-sample Hotelling T 2 statistic. This classifier uses the whole sample of an individual’s measurements for a better support to classification, and the Hotelling T 2 hypothesis testing made applicable by dimensionality reduction. This method was able to discriminate between femero-rotulian (FR) and femero-tibial (FT) knee osteoarthritis kinematic data with an accuracy of 88.1 % , outperforming significantly current state-of-the-art methods which addressed similar problems. Extended to the much harder three-class problem involving pathology categories FR and FT, as well as category FR-FT which represents the incidence of both diseases FR and FT in a same individual, the scheme was able to reach a performance that justifies its further use and investigation in this and other similar applications.

An analysis of 3D knee kinematic data complexity in knee osteoarthritis and asymptomatic controls

Three-dimensional (3D) knee kinematic data, measuring flexion/extension, abduction/adduction, and internal/external rotation angle variations during locomotion, provide essential information to diagnose, classify, and treat musculoskeletal knee pathologies. However, and so across genders, the curse of dimensionality, intra-class high variability, and inter-class proximity make this data usually difficult to interpret, particularly in tasks such as knee pathology classification. The purpose of this study is to use data complexity analysis to get some insight into this difficulty. Using 3D knee kinematic measurements recorded from osteoarthritis and asymptomatic subjects, we evaluated both single feature complexity, where each feature is taken individually, and global feature complexity, where features are considered simultaneously. These evaluations afford a characterization of data complexity independent of the used classifier and, therefore, provide information as to the level of classification performance one can expect. Comparative results, using reference databases, reveal that knee kinematic data are highly complex, and thus foretell the difficulty of knee pathology classification.

Self-reported Instability in Knee Osteoarthritis: A Scoping Review of Literature

BACKGROUND

Knee Osteoarthritis (OA) is a disabling musculoskeletal condition among the elderly. Self-reported instability is one of the impairments associated with osteoarthritis. A complete understanding of the self-reported instability in knee OA is essential, to identify the best strategies for overcoming this impairment. The focus of this scoping review is to provide an overview of evidence supported information about the prevalence and other associated features of selfreported instability in Knee OA. A broad search of the database PubMed with keywords such as knee osteoarthritis and instability resulted in 1075 articles. After title abstract and full-text screening, 19 relevant articles are described in the review. Overall, there is less amount of published literature on this topic. Studies reported prevalence rates of more than 60% for self-reported instability in knee osteoarthritis, which causes functional deterioration and high fear of falls. The most probable causative factors for self-reported instability in knee OA were altered sensory mechanisms and decreased muscle strength.

CONCLUSION

To conclude, self-reported knee instability in knee OA requires thorough evaluation and directed treatment with further studies providing rationalistic evidence-based management strategies. The current literature regarding self-reported knee instability is summarized, highlighting the research gaps.

Modifiable lifestyle factors are associated with lower pain levels in adults with knee osteoarthritis

Pain is the most important osteoarthritis (OA) symptom; however, it is poorly understood and markers of disease severity cannot explain pain variability. With no cure for OA, the authors recognized the need to identify modifiable factors to decrease pain and increase physical function. This study examined factors that characterize OA patients experiencing different levels of pain and investigated the relationships among these factors and OA pain.

BACKGROUND:

With no cure or effective treatments for osteoarthritis (OA), the need to identify modifiable factors to decrease pain and increase physical function is well recognized.

OBJECTIVE:

To examine factors that characterize OA patients at different levels of pain, and to investigate the relationships among these factors and pain.

METHODS:

Details of OA characteristics and lifestyle factors were collected from interviews with healthy adults with knee OA (n=197). The Western Ontario and McMaster Universities Osteoarthritis Index was used to assess pain. Factors were summarized across three pain score categories, and χ² and Kruskal-Wallis tests were used to examine differences. Multiple linear regression analysis using a stepwise selection procedure was used to examine associations between lifestyle factors and pain.

RESULTS:

Multiple linear regression analysis indicated that pain was significantly higher with the use of OA medications and higher body mass index category, and significantly lower with the use of supplements and meeting physical activity guidelines (≥150 min/week). Stiffness and physical function scores, bilateral knee OA, body mass index category and OA medication use were significantly higher with increasing pain, whereas self-reported health, servings of fruit, supplement use and meeting physical activity guidelines significantly lower. No significant differences across pain categories were found for sex, age, number of diseases, duration of OA, ever smoked, alcoholic drinks/week, over-the-counter pain medication use, OA supplement use, physical therapy use, servings of vegetables or minutes walked/week.

CONCLUSIONS:

Healthy weight maintenance, exercise for at least 150 min/week and appropriate use of medications and supplements represent important modifiable factors related to lower knee OA pain.

Comparison of quasi-static and dynamic squats: a three-dimensional kinematic, kinetic and electromyographic study of the lower limbs

Numerous studies have described 3D kinematics, 3D kinetics and electromyography (EMG) of the lower limbs during quasi-static or dynamic squatting activities. One study compared these two squatting conditions but only at low speed on healthy subjects, and provided no information on kinetics and EMG of the lower limbs. The purpose of the present study was to contrast simultaneous recordings of 3D kinematics, 3D kinetics and EMG of the lower limbs during quasi-stat ic and fast-dynamic squats in healthy and pathological subjects. Ten subjects were recruited: five healthy and five osteoarthritis subjects. A motion-capture system, force plate, and surface electrodes respectively recorded 3D kinematics, 3D kinetics and EMG of the lower limbs. Each subject performed a quasi-static squat and several fast-dynamic squats from 0° to 70° of knee flexion. The two squatting conditions were compared for positions where quasi-static and fast-dynamic knee flexion-extension angles were similar. Mean differences between quasi-static and fast-dynamic squats were 1.5° for rotations, 1.9 mm for translations, 2.1% of subjects' body weight for ground reaction forces, 6.6 Nm for torques, 11.2 mm for center of pressure, and 6.3% of maximum fast-dynamic electromyographic activities for EMG. Some significant differences (p<0.05) were found in internal rotation, anterior translation, vertical force and EMG. All differences between quasi-static and fast-dynamic squats were small. 69.5% of compared data were equivalent. In conclusion, this study showed that quasi-static and fast-dynamic squatting activities are comparable in terms of 3D kinematics, 3D kinetics and EMG, although some reservations still remain.

Pharmacologic therapy for osteoarthritis--the era of disease modification

Osteoarthritis (OA) is a prevalent and disabling condition for which few safe and effective therapeutic options are available. Current approaches are largely palliative and in an effort to mitigate the rising tide of increasing OA prevalence and disease impact, modifying the structural progression of OA has become a focus of drug development. This Review describes disease modification and discusses some of the challenges involved in the discovery and development of disease-modifying OA drugs (DMOADs). A variety of targeted agents are in mature phases of development; specific agents that are beyond preclinical development in phase II and III trials and show promise as potential DMOADs are discussed. A research agenda with respect to disease modification in OA is also provided, and some of the future challenges we face in this field are discussed.