The Influence of Knee Pain Location on Symptoms, Functional Status, and Knee-related Quality of Life in Older Adults With Chronic Knee Pain: Data From the Osteoarthritis Initiative

Chronic knee pain while awaiting arthroplasty is associated with worsening joint-specific function, health-related quality of life and personal wellbeing, and increased use of opioid analgesia

Aims

To assess whether chronic knee pain (CKP) influenced health-related quality of life (HRQoL), knee-specific health, wellbeing, and use of opioid analgesia, and identify variables associated with CKP in patients awaiting knee arthroplasty.

Methods

This study included 217 patients (mean age 69.7 years (SD 8.7), 116 female (53%)) who completed questionnaires that included the EuroQol five-dimension questionnaire (EQ-5D) and EuroQol-visual analogue scale (EQ-VAS), Oxford Knee Score (OKS), and wellbeing assessments at six and 12 months after being listed for surgery. Analgesia use at 12 months was also recorded. CKP was defined using the OKS pain score (PS) of ≤ 14 points at 12 months.

Results

At 12 months, 169 patients (77.9%) had CKP. Compared with those without CKP, those with CKP had clinically meaningfully worse HRQoL and knee-specific health at 12 months and were more likely to have a health state worse than death (odds ratio (OR) 29.7, 95% CI 4.0 to 220.2; p < 0.001). The CKP group were more likely to use weak (OR 3.03, 95% CI 1.65 to 7.96; p = 0.001) and strong (OR 11.8, 95% CI 1.58 to 88.88; p = 0.001) opioids for analgesia. The CKP group had worse overall wellbeing with significantly (p < 0.001) lower satisfaction with life, life being worthwhile and happiness, and increased anxiety. The CKP group had a significant (p < 0.001) deterioration in their OKS, OKS-PS, EQ-5D, and EQ-VAS from six to 12 months, which was not observed in the group without CKP. A worse OKS-PS at six months was independently associated with an increased risk of CKP, and a threshold value of < 13 (sensitivity 91.7%, specificity 94.7%) was an excellent discriminator (area under the curve 96.9, 95% CI 94.2 to 99.6; p < 0.001).

Conclusion

Four in five patients had CKP after waiting 12 months, which was associated with deteriorations in HRQoL and knee health, worse wellbeing, and increased opioid analgesia use. The OKS-PS at six months could be used to identify patients at risk of CKP after 12 months of waiting.

Experimentally induced pain increases absolute but not relative errors and reduces variability in joint repositioning of the knee joint in healthy participants

BACKGROUND

Joint position sense (JPS) plays an important role in knee joint function. Despite the possible influence of pain on the proprioceptive system, the effects of experimental muscle pain on knee JPS have not been studied.

OBJECTIVES

To investigate if experimentally induced muscle pain affects knee JPS in healthy participants.

METHODS

Measurements of knee JPS were conducted before and after the injection of 5.8% sterile hypertonic saline in the vastus medialis muscle of 26 healthy physically active adults. Knee JPS was assessed through a passive/active repositioning paradigm in target angles of 15°, 45° and 60° using an isokinetic dynamometer. Absolute and relative angular errors were calculated. The coefficient of variation analysis was used to assess differences in the angles' variability during the repositioning task.

RESULTS

Absolute angular error increased in all three angles following experimentally induced pain. The difference was statistically significant at 45° (p = 0.003, d = 0.6) and 15° (p = 0.047, d = 0.4) but not at 60° (p = 0.064, d = 0.4). Relative error did not show directional bias at 45° (p = 0.272, d = 0.2), 15° (p = 0.483, d = 0.1) or 60° (p = 0.091, d = 0.3). The coefficient of variation analysis revealed a statistically significant reduction in variability at angles of 60° (p = 0.002, d = 0.7) and 15° (p = 0.031, d = 0.4) after the pain intervention.

CONCLUSION

The presence of experimentally induced muscle pain affects the ability of healthy participants to accurately reposition the knee at two angles of knee flexion and reduces movement variability during the repositioning task. Further research is required to determine if these deficits also impact patients with clinical knee pain.

Accelerated Brain Aging Mediates the Association Between Psychological Profiles and Clinical Pain in Knee Osteoarthritis

Chronic pain is driven by factors across the biopsychosocial spectrum. Previously, we demonstrated that magnetic resonance images (MRI)-based brain-predicted age differences (brain-PAD: brain-predicted age minus chronological age) were significantly associated with pain severity in individuals with chronic knee pain. We also previously identified four distinct, replicable, multidimensional psychological profiles significantly associated with clinical pain. The brain aging-psychological characteristics interface in persons with chronic pain promises elucidating factors contributing to their poor health outcomes, yet this relationship is barely understood. That is why we examined the interplay between the psychological profiles in participants having chronic knee pain impacting function, brain-PAD, and clinical pain severity. Controlling for demographics and MRI scanner, we compared the brain-PAD among psychological profiles at baseline (n = 164) and over two years (n = 90). We also explored whether profile-related differences in pain severity were mediated by brain-PAD. Brain-PAD differed significantly between profiles (ANOVA's omnibus test, P = .039). Specifically, participants in the profile 3 group (high negative/low positive emotions) had an average brain-PAD ∼4 years higher than those in profile- (low somatic reactivity), with P = .047, Bonferroni-corrected, and than those in profile 2 (high coping), with P = .027, uncorrected. Repeated measures ANOVA revealed no significant change in profile-related brain-PAD differences over time, but there was a significant decrease in brain-PAD for profile 4 (high optimism/high positive affect), with P = .045. Moreover, profile-related differences in pain severity at baseline were partly explained by brain-PAD differences between profile 3 and 1, or 2; but brain-PAD did not significantly mediate the influence of variations in profiles on changes in pain severity over time. PERSPECTIVE: Accelerated brain aging could underlie the psychological-pain relationship, and psychological characteristics may predispose individuals with chronic knee pain to worse health outcomes via neuropsychological processes.

Joint contributions to sagittal plane total support moment in patients with knee osteoarthritis after anterior cruciate ligament reconstruction

BACKGROUND

Patients with anterior cruciate ligament reconstruction (ACLR) demonstrate lower knee loading. This study aimed to determine whether sagittal plane TSM and joint contributions to total support moment (TSM) in the surgical limb are different between athletes who did and did not show radiological features of knee OA at 2 years after ACLR during triple hops (TH), single hop (TH), single-legged vertical jump (VJ), and walking.

METHODS

Forty-one athletes with 2 years of unilateral ACLR surgery participated in this cross-sectional study. Athletes completed motion analysis testing of single-legged TH, SH, VJ, and walking tasks. Sagittal plane TSM and individual joint (ankle, knee, and hip) contributions to TSM were computed at peak knee flexion angle (TSM-PKF). Posterior-anterior radiographs were completed in standing and 30° knee flexion. Kellgren-Lawrence (KL) system was used to identify radiological features of knee OA in the medial compartment of the reconstructed knee (OA-group: KL ≥2; Non-OA group: KL<2).

RESULTS

There was a significant group-by-joint-by-task interaction for joint contributions to TSM-PKF (p = 0.012), with the OA-group (n = 13) had lower knee and higher hip contributions compared to the non-OA group during TH, SH, and VJ (p ≤ 0.049). There was a significant joint-by-group interaction for the joint contributions to TSM-PKF (p = 0.004), with the OA-group having lower knee (p = 0.003) and higher hip (p = 0.001) contributions compared to the Non-OA group.

SIGNIFICANCE

The OA-group exhibited lower knee and higher hip contributions to the sagittal plane TSM compared to the Non-OA group during the landing phase of single-limb high-demand activities. The OA-group exhibited decreased knee loading and compensated by shifting the mechanical load to the hip joint within the reconstructed knee. Decreased knee loading in the OA-group may have affected the required mechanical loading to maintain knee metabolism and integrity.

Feasibility and applicability of locomotive syndrome risk test in elderly patients who underwent total knee arthroplasty

OBJECTIVES

The concept of locomotive syndrome (LS) and its evaluation method, the LS risk test, have been applied in an integrated manner to capture the decline in mobility resulting from musculoskeletal disorders. The purpose of this study was to evaluate the impact of total knee arthroplasty (TKA) in the elderly with knee osteoarthritis, a common disorder found in LS.

METHODS

A total of 111 patients were registered prior to TKA and postoperatively followed up for 1 year. Three components of the LS risk test (the two-step test, stand-up test, and Geriatric Locomotive Function Scale-25) were assessed pre- and postoperatively.

RESULTS

After surgery, all three components of the test showed significant improvements from the baseline. The ratio of Stage 3 LS patients (progressed stage of decrease in mobility) reduced from 82.3% to 33.9% postoperatively. There was no significant difference in the degree of change in the scores between the younger (60-74 years) and older (≥75 years) age groups.

CONCLUSIONS

We found that TKA has a major impact in preventing the progression of LS in patients with knee osteoarthritis. The LS risk test is a feasible tool for the longitudinal evaluation of patients with musculoskeletal diseases of varying severity and with multiple symptoms.

Extracorporeal Shock Wave Therapy for the Treatment of Musculoskeletal Pain: A Narrative Review

Extracorporeal shock waves are high-intensity mechanical waves (500-1000 bar) of a microsecond duration with a morphology characterized by a rapid positive phase followed by a negative phase.

BACKGROUND

Extracorporeal shock waves have been used for pain treatment for various sub-acute and chronic musculoskeletal (MSK) problems since 2000. The aim of this article is to update information on the role of extracorporeal shock wave therapy (ESWT) in the treatment of various pathologies that cause MSK pain.

METHODS

Given that in the last two years, articles of interest (including systematic reviews and meta-analyses) have been published on less known indications, such as low back pain, nerve entrapments, osteoarthritis and bone vascular diseases, a literature search was conducted in PubMed, the Cochrane Database, EMBASE, CINAHL and PEDro, with the aim of developing a narrative review of the current literature on this topic. The purposes of the review were to review possible new mechanisms of action, update the level of evidence for known indications and assess possible new indications that have emerged in recent years.

RESULTS

Although extracorporeal shock waves have mechanical effects, their main mechanism of action is biological, through a phenomenon called mechanotransduction. There is solid evidence that supports their use to improve pain in many MSK pathologies, such as different tendinopathies (epicondylar, trochanteric, patellar, Achilles or calcific shoulder), plantar fasciitis, axial pain (myofascial, lumbar or coccygodynia), osteoarthritis and bone lesions (delayed union, osteonecrosis of the femoral head, Kienbock's disease, bone marrow edema syndrome of the hip, pubis osteitis or carpal tunnel syndrome). Of the clinical indications mentioned in this review, five have a level of evidence of 1+, eight have a level of evidence of 1-, one indication has a level of evidence of 2- and two indications have a level of evidence of 3.

CONCLUSIONS

The current literature shows that ESWT is a safe treatment, with hardly any adverse effects reported. Furthermore, it can be used alone or in conjunction with other physical therapies such as eccentric strengthening exercises or static stretching, which can enhance its therapeutic effect.

Knee Cartilage Lesion Management-Current Trends in Clinical Practice

Many patients, particularly those aged above 40, experience knee joint pain, which hampers both sports activities and daily living. Treating isolated chondral and osteochondral defects in the knee poses a significant clinical challenge, particularly in younger patients who are not typically recommended partial or total knee arthroplasty as alternatives. Several surgical approaches have been developed to address focal cartilage defects. The treatment strategies are characterized as palliation (e.g., chondroplasty and debridement), repair (e.g., drilling and microfracture), or restoration (e.g., autologous chondrocyte implantation, osteochondral autograft, and osteochondral allograft). This review offers an overview of the commonly employed clinical methods for treating articular cartilage defects, with a specific focus on the clinical trials conducted in the last decade. Our study reveals that, currently, no single technology fully meets the essential requirements for effective cartilage healing while remaining easily applicable during surgical procedures. Nevertheless, numerous methods are available, and the choice of treatment should consider factors such as the location and size of the cartilage lesion, patient preferences, and whether it is chondral or osteochondral in nature. Promising directions for the future include tissue engineering, stem cell therapies, and the development of pre-formed scaffolds from hyaline cartilage, offering hope for improved outcomes.

ADAPTations to low load blood flow restriction exercise versus conventional heavier load resistance exercise in UK military personnel with persistent knee pain: protocol for the ADAPT study, a multi-centre randomized controlled trial

BACKGROUND

Muscle atrophy, muscle weakness and localised pain are commonly reported following musculoskeletal injury (MSKI). To mitigate this risk and prepare individuals to return to sport or physically demanding occupations, resistance training (RT) is considered a vital component of rehabilitation. However, to elicit adaptations in muscle strength, exercise guidelines recommend lifting loads ≥ 70% of an individual's one repetition maximum (1-RM). Unfortunately, individuals with persistent knee pain are often unable to tolerate such high loads and this may negatively impact the duration and extent of their recovery. Low load blood flow restriction (LL-BFR) is an alternative RT technique that has demonstrated improvements in muscle strength, hypertrophy, and pain in the absence of high mechanical loading. However, the effectiveness of high-frequency LL-BFR in a residential rehabilitation environment remains unclear. This study will compare the efficacy of high frequency LL-BFR to 'conventional' heavier load resistance training (HL-RT) on measures of physical function and pain in adults with persistent knee pain.

METHODS

This is a multicentre randomised controlled trial (RCT) of 150 UK service personnel (aged 18-55) admitted for a 3-week residential rehabilitation course with persistent knee pain. Participants will be randomised to receive: a) LL-BFR delivered twice daily at 20% 1-RM or b) HL-RT three-times per week at 70% 1-RM. Outcomes will be recorded at baseline (T1), course discharge (T2) and at three-months following course (T3). The primary outcome will be the lower extremity functional scale (LEFS) at T2. Secondary outcomes will include patient reported perceptions of pain, physical and occupational function and objective measures of muscle strength and neuromuscular performance. Additional biomechanical and physiological mechanisms underpinning both RT interventions will also be investigated as part of a nested mechanistic study.

DISCUSSION

LL-BFR is a rehabilitation modality that has the potential to induce positive clinical adaptations in the absence of high mechanical loads and therefore could be considered a treatment option for patients suffering significant functional deficits who are unable to tolerate heavy load RT. Consequently, results from this study will have a direct clinical application to healthcare service providers and patients involved in the rehabilitation of physically active adults suffering MSKI.

TRIAL REGISTRATION

ClinicalTrials.org reference number, NCT05719922.

The Patellostabilometer: A New Device for Quantification of Mediolateral Patella Displacement

Mediolateral patella displacement is of interest for diagnostics and clinically relevant research questions. Apart from manual testing, no standardized method is currently available. Proper quantification of patella mobility is necessary to better understand pathologies at the patellofemoral joint. Patella mobility was assessed in 25 healthy individuals using a Patellostabilometer, a new prototype instrument for quantification of the mediolateral patella displacement. The participants underwent measurements of the mediolateral displacement three times using the Patellostabilometer. A maximal force of 10 N was applied for patella movement. Additionally, leg length and circumference of the knee, upper- and lower-leg were measured. Lateral patella displacement of 18.27 ± 3.76 mm (range 15.85-20.64 mm, interquartile range (IQR) of 4.79) was measured. The medial patella displacement showed 24.47 ± 6.59 mm (range 19.29-29.76 mm, IQR of 10.47). The test-retest measurement error was 2.32 ± 1.76 mm (IQR of 2.38 mm), with five outliers. There was greater test-retest variability between the measurements of the medial displacement compared to the lateral one. The test-retest variability reached 7% of the patella displacement. Other parameters provided no significant correlations. Based on the natural patellofemoral mobility, a precise and clinically relevant quantification of patella mobility is allowed.

Multimodal prediction of pain and functional outcomes 6 months following total knee replacement: a prospective cohort study

BACKGROUND

Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence and impact around the globe. In the U.S., the rising prevalence of knee OA has been paralleled by an increase in annual rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, post-operative trajectories of pain and functional status vary substantially; a significant minority of patients report ongoing pain and impaired function following TKA. A number of studies have identified sets of biopsychosocial risk factors for poor post-TKA outcomes (e.g., comorbidities, negative affect, sensory sensitivity), but few prospective studies have systematically evaluated the unique and combined influence of a broad array of factors.

METHODS

This multi-site longitudinal cohort study investigated predictors of 6-month pain and functional outcomes following TKA. A wide spectrum of relevant biopsychosocial predictors was assessed preoperatively by medical history, patient-reported questionnaire, functional testing, and quantitative sensory testing in 248 patients undergoing TKA, and subsequently examined for their predictive capacity.

RESULTS

The majority of patients had mild or no pain at 6 months, and minimal pain-related impairment, but approximately 30% reported pain intensity ratings of 3/10 or higher. Reporting greater pain severity and dysfunction at 6 months post-TKA was predicted by higher preoperative levels of negative affect, prior pain history, opioid use, and disrupted sleep. Interestingly, lower levels of resilience-related "positive" psychosocial characteristics (i.e., lower agreeableness, lower social support) were among the strongest, most consistent predictors of poor outcomes in multivariable linear regression models. Maladaptive profiles of pain modulation (e.g., elevated temporal summation of pain), while not robust unique predictors, interacted with psychosocial risk factors such that the TKA patients with the most pain and dysfunction exhibited lower resilience and enhanced temporal summation of pain.

CONCLUSIONS

This study underscores the importance of considering psychosocial (particularly positively-oriented resilience variables) and sensory profiles, as well as their interaction, in understanding post-surgical pain trajectories.

Could emotional and sensitization status affect postural sway in adults with knee osteoarthritis?

BACKGROUND AND PURPOSE

The manipulation of sensory conditions and attentional demand affect the postural sway in older adults with knee osteoarthritis (KOA). However, it is not known if emotional and sensitization status affects postural sway in this population. This study aimed to test if older adults with mild and moderate knee osteoarthritis with symptoms of depression and high sensitization would change the profile of postural sway.

METHODS

Design: A cross-sectional study was undertaken.

PARTICIPANTS

The center of pressure parameters of 30 older adults with mild and moderate knee osteoarthritis and 15 healthy controls were evaluated under different conditions manipulating the visual and attentional demand. We used the pressure pain threshold to measure the sensitization status. Furthermore, we applied the Beck Depression Inventory index to assess emotional status.

RESULTS

Manipulating the visual demand affected the center of pressure parameters for both groups, without differences between them. Compared to the healthy control group, the knee osteoarthritis group presented with worse scores on the Beck Depression Inventory, lower pressure pain threshold scores, and the correlations between the symptoms of depression and sensitization status ranged from weak to moderate. Finally, in the knee osteoarthritis group, we observed few and weak significant associations between the center of pressure parameters and the Beck Depression Inventory and the pressure pain threshold scores.

DISCUSSION

Emotional and sensitization status seem not to be more associated with the center of pressure of older adults with mild to moderate KOA than healthy adults. Thus, it suggests that this population can safely maintain postural sway, irrespective of depression symptoms and high sensitization.

Musculoskeletal pain in Parkinson's disease: a narrative review

The prevalence of musculoskeletal (MSK) pain in people with Parkinson's disease (PD) is higher than that of age-matched controls. In this review, we outline what is known about MSK pain in PD, focusing on the neck, shoulder, knee, hip and low back. We also compare what is known about MSK pain in PD to what is known in older adults without PD. Finally, we outline areas of for future research related to MSK pain in people with PD.

Preliminary Evaluation of a New Orthotic for Patellofemoral and Multicompartment Knee Osteoarthritis

Purpose

Traditional knee osteoarthritis (OA) braces are usually indicated for a minority of patients with knee OA, as they are only suitable for those with unicompartmental disease affecting the tibiofemoral joint. A new assistive brace design is intended for use in a wider range of knee OA patients with heterogeneous symptoms characteristic of patellofemoral, tibiofemoral, or multicompartmental knee OA. The purpose of this case series was to explore whether the use of this novel “tricompartment offloader” (TCO) brace was associated with clinically relevant improvements in pain and function.

Materials and Methods

A retrospective analysis of individuals with knee OA (n = 40) was conducted to assess pain, function, physical activity, and use of medication and other treatments before and after brace use. Validated outcome measures including the Visual Analog Scale (VAS) and Lower Extremity Functional Scale (LEFS) were used to assess pain and physical function (primary outcome measures). Exploratory measures were used to quantify physical activity levels and use of medication and other treatments (secondary outcome measures).

Results

Average total pain (VAS) scores decreased by 36.6 mm and physical function (LEFS) scores increased by 16.0 points following the use of the TCO brace. Overall, 70% of the participants indicated increased weekly physical activity and 60% reported a decrease in their use of at least one other treatment.

Conclusions

Results from this case series suggest that the TCO brace shows strong potential to fill a conservative treatment gap for patients with heterogeneous symptoms of knee OA that are characteristic of patellofemoral or multicompartment disease. Further investigation is warranted.

Biological resurfacing of grade IV articular cartilage ulcers in knee joint with Hyalofast

INTRODUCTION

Hyalofast grafting with microfracture is a new minimally invasive treatment method being proposed for joint cartilage defects. This study was done to measure the clinical efficacy of Hyalofast grafting after microfractures.

METHODS

Forty-six patients were assessed for knee function using knee injury and osteoarthritis outcome score (KOOS) after undergoing microfracture and Hyalofast grafting surgery. We further divided the 46 patients into a group of 10 patients who had no associated procedures done with the microfracture and Hyalofast grafting surgery. All patients had magnetic resonance imaging (MRI) of the affected knee pre-surgery and two patients had MRI done post-surgery. Due to another unrelated injury, we were also able to obtain further arthroscopic findings of another patient's knee 18 months after microfracture and Hyalofast grafting.

RESULTS

There was a statistically significant improvement in all categories of the KOOS (symptoms, pain, daily living, sports and quality of life) compared between years 1, 2 and 3 against pre-surgery. For the subgroup of Hyalofast only, there was a statistically significant improvement in symptoms, pain and daily living categories of the KOOS compared between years 1, 2 and 3 against pre-surgery.

CONCLUSIONS

Our study shows that Hyalofast grafting after microfracture is a viable alternative to treatment for patients with grade 4 cartilage ulcers.

Dual-Task Effects on Performance of Gait and Balance in People with Knee Pain: A Systematic Scoping Review

Dual-task paradigms have been increasingly used to assess the interaction between cognitive demands and the control of balance and gait. The interaction between functional and cognitive demands can alter movement patterns and increase knee instability in individuals with knee conditions, such as knee anterior cruciate ligament (ACL) injury or osteoarthritis (OA). However, there is no consensus on the effects of dual-task on gait mechanics and balance in those individuals. This systematic scoping review aims to examine the impact of dual-task gait and standing balance on motor and cognitive performance in individuals with knee OA or ACL injury. A comprehensive search of MEDLINE, PubMed, Web of Science, and EMBASE electronic databases up until December 2019 was carried out. Inclusion criteria was limited to include dual-task studies that combined cognitive tasks performed simultaneously with gait or standing balance in individuals with knee OA or ACL injuries. In total, fifteen studies met the inclusion criteria, nine articles examined dual-task effects on balance, and six articles reported the effects of dual-task on gait. The total number of individuals included was 230 individuals with ACL injuries, and 168 individuals with knee OA. A decline in gait and balance performance during dual-task testing is present among individuals with ACL injury and/or ACL reconstruction and knee OA. Further research is required, but dual taking assessment could potentially be used to identify individuals at risk of falling or further injury and could be used to develop targeted rehabilitation protocols. A variety of outcome measures have been used across the studies included, making comparisons difficult. The authors, therefore, recommend developing a standardized set of biomechanical balance variables.

Noggin Inhibits IL-1β and BMP-2 Expression, and Attenuates Cartilage Degeneration and Subchondral Bone Destruction in Experimental Osteoarthritis

Osteoarthritis (OA) is a chronic inflammatory and progressive joint disease that results in cartilage degradation and subchondral bone remodeling. The proinflammatory cytokine interleukin 1 beta (IL-1β) is abundantly expressed in OA and plays a crucial role in cartilage remodeling, although its role in the activity of chondrocytes in cartilage and subchondral remodeling remains unclear. In this study, stimulating chondrogenic ATDC5 cells with IL-1β increased the levels of bone morphogenetic protein 2 (BMP-2), promoted articular cartilage degradation, and enhanced structural remodeling. Immunohistochemistry staining and microcomputed tomography imaging of the subchondral trabecular bone region in the experimental OA rat model revealed that the OA disease promotes levels of IL-1β, BMP-2, and matrix metalloproteinase 13 (MMP-13) expression in the articular cartilage and enhances subchondral bone remodeling. The intra-articular injection of Noggin protein (a BMP-2 inhibitor) attenuated subchondral bone remodeling and disease progression in OA rats. We also found that IL-1β increased BMP-2 expression by activating the mitogen-activated protein kinase (MEK), extracellular signal-regulated kinase (ERK), and specificity protein 1 (Sp1) signaling pathways. We conclude that IL-1β promotes BMP-2 expression in chondrocytes via the MEK/ERK/Sp1 signaling pathways. The administration of Noggin protein reduces the expression of IL-1β and BMP-2, which prevents cartilage degeneration and OA development.

The addition of blood flow restriction to resistance exercise in individuals with knee pain: a systematic review and meta-analysis

BACKGROUND

Blood flow restriction (BFR) is an effective clinical intervention used to increase strength in healthy individuals. However, its effects on pain and function in individuals with knee pain are unknown.

OBJECTIVE

To determine the effectiveness of adding BFR to resistance exercise for pain relief and improvement of function in patients with knee pain.

METHODS

Systematic review with meta-analysis of randomized clinical trials. Medline, Central, Embase, PEDro, Lilacs, CINAHL, SPORTDiscus, and Web of Science databases were searched from inception to May 2019. Randomized clinical trials that compared resistance exercise with or without BFR to treat knee pain and function in individuals older than 18 years of age with knee pain were included.

RESULTS

Eight randomized clinical trials met the eligibility criteria and for the quantitative synthesis, five studies were included. The pooled standardized mean difference (SMD) estimate showed that resistance exercises with BFR was not more effective than resistance exercises for reducing pain (SMD: -0.37cm, 95% CI=-0.93, 0.19) and improving knee function (SMD=-0.23 points, 95% CI=-0.71, 0.26) in patients with knee pain.

CONCLUSION

In the short term, there is low quality of evidence that resistance exercise with BFR does not provide significant differences in pain relief and knee function compared to resistance exercises in patients with knee pain. PROSPERO registration number: CRD42018102839.

Individual joint contributions to the total support moment during the sit-to-stand task differentiate mild and moderate knee osteoarthritis

BACKGROUND

Knee osteoarthritis tends to modify the kinematics and kinetics of the sit-to-stand task. However, it is not clear whether the different degrees of knee osteoarthritis differentiate regarding these aspects. The objective was to identify if the trunk flexion, lower limb kinetics, total support moment, and individual joint contributions to the total support moment during the sit-to-stand task are different between patients with mild and moderate knee osteoarthritis.

METHODS

Sixty-two participants were grouped as follows: moderate knee osteoarthritis (n = 16), mild knee osteoarthritis (n = 25), and controls (n = 21). The participants performed a sit-to-stand task, which was analyzed using a 3D-motion system and a force plate.

FINDINGS

The three phases of the sit-to-stand task were analyzed. During Phase₁, the moderate osteoarthritis group decreased the total support moment (P = 0.012). During Phase₂, the moderate osteoarthritis group showed higher trunk flexion (P = 0.023) and lower internal hip and knee extension moments (P ≤ 0.001 and P ≤ 0.040, respectively) when compared to controls. Also in Phase₂, both the mild and moderate groups used lower total support moment (P = 0.019, and P ≤ 0.001, respectively). When compared to the controls and mild osteoarthritis group_, those with moderate osteoarthritis presented higher hip joint contribution to the total support moment (P ≤ 0.001 and P = 0.006, respectively) as well as lower knee joint contribution (P ≤ 0.003 and P = 0,013, respectively).

INTERPRETATION

Those with moderate osteoarthritis showed modified sit-to-stand movement pattern. While in Phase₃ a higher contribution of the hip joint to the total support moment was observed, during previous phases the individuals were able to decrease the load on the knee without influencing the lower limb load distribution.

Longitudinal Relationship Between Knee Pain Status and Incident Frailty: Data from the Osteoarthritis Initiative

Objective

Examine the longitudinal association between knee pain and prefrailty/frailty.

Design

Longitudinal study.

Setting

Five clinical centers across the United States.

Subject

Data from 3,053 nonfrail participants aged 45-79 years at baseline from the Osteoarthritis Initiative.

Methods

According to self-reported knee pain at baseline, the participants were placed into three groups: no knee pain (N = 1,600), unilateral knee pain (N = 822), and bilateral knee pain (N = 631). Frailty status was assessed over time using the five frailty indicators (unintentional weight loss, exhaustion, weak energy, slow gait speed, and little physical activity). Based on the number of frailty indicators present, prefrailty (1-2) and frailty (≥3) were diagnosed. Generalized estimating equations logistic regression analyses were conducted to examine the relationship between knee pain status and prefrailty/frailty.

Results

After adjusting for age, sex, race, education, marital status, smoking status, comorbidities, and body mass index, unilateral knee pain at baseline was associated with an increased odds of developing prefrailty (odds ratio [OR] = 1.14, 95% confidence interval [CI] = 1.01-1.27) and frailty (OR = 1.89, 95% CI = 1.38-2.62), and bilateral knee pain at baseline was also associated with an increased risk of prefrailty (OR = 1.41, 95% CI = 1.24-1.62) and frailty (OR = 2.21, 95% CI = 1.63-3.01) over time in comparison with no knee pain. The interaction of knee pain status by time was not significantly associated with either prefrailty or frailty.

Conclusions

Knee pain (particularly bilateral knee pain) is associated with an increased risk of developing prefrailty and frailty over time.

Alignment differs between patellofemoral osteoarthritis cases and matched controls: An upright 3D MRI study

Patellofemoral (PF) osteoarthritis (OA) is a prevalent and clinically important knee OA subgroup. Malalignment may be an important risk factor for PF OA. However, little is known about alignment in PF OA, particularly in an upright, weightbearing environment. Using a vertically-oriented open-bore MR scanner, we evaluated 3D knee alignment in 15 PF OA cases and 15 individually matched asymptomatic controls. We imaged one knee per participant while they stood two-legged at four flexion angles (0°, 15°, 30°, 45°), and also while they stood one-legged at 30° knee flexion. We calculated 3D patellofemoral and tibiofemoral alignment. Using mixed effects models, four of the five patellofemoral measures differed by group. For key measures, PF OA patellae were 6.6° [95%CI 5.0, 8.2] more laterally tilted, 2.4 mm [1.3, 3.5] more laterally translated, and at least 3.7 mm [0.2, 7.2] more proximally translated compared to controls (more with knees flexed). Alignment did not differ between two-legged stance and one-legged stance in either group. Statement of Clinical Significance: Our study demonstrated significant and clinically relevant differences in alignment between PF OA cases and controls in upright standing and squatting positions. Our findings were similar to those in previous studies of PF OA using traditional MR scanners in supine positions, supporting the clinical usefulness of existing methods aimed at identifying individuals who may benefit from interventions designed to correct malalignment. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. 9999:1-9, 2019.

Efficacy of extracorporeal shock wave therapy for knee tendinopathies and other soft tissue disorders: a meta-analysis of randomized controlled trials

Background

Extracorporeal shock-wave therapy (ESWT), which can be divided into radial shock-wave therapy (RaSWT) and focused shock-wave therapy (FoSWT), has been widely used in clinical practice for managing orthopedic conditions. The aim of this study was to determine the clinical efficacy of ESWT for knee soft tissue disorders (KSTDs) and compare the efficacy of different shock-wave types, energy levels, and intervention durations.

Methods

We performed a comprehensive search of online databases and search engines without restrictions on the publication year or language. We selected randomized controlled trials (RCTs) reporting the efficacy of ESWT for KSTDs and included them in a meta-analysis and risk of bias assessment. The pooled effect sizes of ESWT were estimated by computing odds ratios (ORs) with 95% confidence intervals (CIs) for the treatment success rate (TSR) and standardized mean differences (SMDs) with 95% CIs for pain reduction (i.e., the difference in pain relief, which was the change in pain from baseline to the end of RCTs between treatment and control groups) and for restoration of knee range of motion (ROM).

Results

We included 19 RCTs, all of which were of high or medium methodological quality and had a Physiotherapy Evidence Database score of ≥5/10. In general, ESWT had overall significant effects on the TSR (OR: 3.36, 95% CI: 1.84–6.12, P < 0.0001), pain reduction (SMD: − 1.49, 95% CI: − 2.11 to − 0.87, P < 0.00001), and ROM restoration (SMD: 1.76, 95% CI: 1.43–2.09, P < 0.00001). Subgroup analyses revealed that FoSWT and RaSWT applied for a long period (≥1 month) had significant effects on pain reduction, with the corresponding SMDs being − 3.13 (95% CI: − 5.70 to − 0.56; P = 0.02) and − 1.80 (95% CI: − 2.52 to − 1.08; P < 0.00001), respectively. Low-energy FoSWT may have greater efficacy for the TSR than high-energy FoSWT, whereas the inverse result was observed for RaSWT.

Conclusions

The ESWT exerts an overall effect on the TSR, pain reduction, and ROM restoration in patients with KSTDs. Shock-wave types and application levels have different contributions to treatment efficacy for KSTDs, which must be investigated further for optimizing these treatments in clinical practice.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2204-6) contains supplementary material, which is available to authorized users.

Total knee arthroplasty status and patient-reported, knee-related quality of life over a 4-year follow-up period: data from the osteoarthritis initiative

PURPOSE

To examine the relationship between baseline total knee arthroplasty (TKA) status and patient-reported, knee-related quality of life (QoL) over a 4-year follow-up relative to no knee osteoarthritis (OA).

PATIENTS AND METHODS

Data from the Osteoarthritis Initiative were included, comprising 4,674 adults aged 45-79 years at baseline. Patients were categorized into four groups: no knee OA (n=3,711), non-TKA (n=902), pre-TKA (n=36), and post-TKA (n=25). QoL was measured using the Knee Injury Osteoarthritis Outcome Score-QoL subscale. General linear mixed models were used for the relationship between TKA and QoL.

RESULTS

After adjusting for covariates, a reduced QoL was noted for patients in the non-TKA (mean [standard error], -13.97 [0.73]; P<0.0001), pre-TKA (-21.34 [3.57]; P<0.0001), and post-TKA (-9.68 [3.94]; P=0.0143) groups compared with the no knee OA group. QoL in the non-TKA group also decreased over time (-0.16 [0.07]; P=0.226).

CONCLUSION

Non-, pre-, and post-TKA status is associated with a lower QoL.

Associations between changes in knee pain location and clinical symptoms in people with medial knee osteoarthritis using footwear for self-management: an exploratory study

OBJECTIVE

To examine whether change in pain location is associated with clinically-relevant improvements in walking pain severity and physical dysfunction in people with medial tibiofemoral osteoarthritis (OA) using footwear for self-management.

DESIGN

We analysed a sub-set of 91 participants pooled from both arms of a 6-month randomised controlled trial of footwear for knee OA. The Photographic Knee Pain Map was self-administered to generate changes in the number of painful zones ('unchanged', 'increased', 'decreased') and anatomical patterns of pain ('unchanged', 'no longer diffuse', 'becoming diffuse', 'other pattern changes'). Improvement in symptoms was determined using the minimum clinically important differences (MCIDs) in pain severity on a numeric rating scale, and function with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Fisher's exact tests examined differences in symptom improvement across categories of change and odds ratios (ORs, 95% CI) were calculated (adjusted for treatment allocation).

RESULTS

Seventy-four percent (n = 67) of participants reported a change in pain location, and 46-50% (n = 42-45) reported clinically-relevant improvements in pain and function respectively. Fewer participants 'becoming diffuse' reported improved pain (n = 0, 0%) when compared to the other pattern change categories (P = 0.012). Participants with 'no longer diffuse' (OR (95% CI) = 0.3 (0.1-0.9) or 'becoming diffuse' (OR (95% CI) = 0.0 (0.0-0.4) pain patterns had significantly lower odds of improved function than those with 'other pattern changes'.

CONCLUSION

Participants either developing into, or changing from, diffuse pain patterns were less likely to experience improvement in pain and/or function when self-managing with footwear.