Project description:BackgroundExperimental and clinical evidence support a link between body representations and pain. This proof-of-concept study in people with painful knee osteoarthritis (OA) aimed to determine if: (i) visuotactile illusions that manipulate perceived knee size are analgesic; (ii) cumulative analgesic effects occur with sustained or repeated illusions.MethodsParticipants with knee OA underwent eight conditions (order randomised): stretch and shrink visuotactile (congruent) illusions and corresponding visual, tactile and incongruent control conditions. Knee pain intensity (0-100 numerical rating scale; 0 = no pain at all and 100 = worst pain imaginable) was assessed pre- and post-condition. Condition (visuotactile illusion vs control) × Time (pre-/post-condition) repeated measure ANOVAs evaluated the effect on pain. In each participant, the most beneficial illusion was sustained for 3 min and was repeated 10 times (each during two sessions); paired t-tests compared pain at time 0 and 180s (sustained) and between illusion 1 and illusion 10 (repeated).ResultsVisuotactile illusions decreased pain by an average of 7.8 points (95% CI [2.0-13.5]) which corresponds to a 25% reduction in pain, but the tactile only and visual only control conditions did not (Condition × Time interaction: p = 0.028). Visuotactile illusions did not differ from incongruent control conditions where the same visual manipulation occurred, but did differ when only the same tactile input was applied. Sustained illusions prolonged analgesia, but did not increase it. Repeated illusions increased the analgesic effect with an average pain decrease of 20 points (95% CI [6.9-33.1])-corresponding to a 40% pain reduction.DiscussionVisuotactile illusions are analgesic in people with knee OA. Our results suggest that visual input plays a critical role in pain relief, but that analgesia requires multisensory input. That visual and tactile input is needed for analgesia, supports multisensory modulation processes as a possible explanatory mechanism. Further research exploring the neural underpinnings of these visuotactile illusions is needed. For potential clinical applications, future research using a greater dosage in larger samples is warranted.
Project description:Knee arthroscopy has evolved greatly from its inception in the 20th century. Arthroscopic synovectomy is performed in the case of infection or significant synovitis. We continue to develop more minimally invasive procedures, and the NanoScope (Arthrex, Naples, FL) has provided a new generation of possibilities. The system does not require the use of a standard incision or portal, and using the GraftNet (Arthrex), we can harvest tissue with a standard shaver for further evaluation. This technique provides an option to perform a synovial and bone biopsy in a painful total knee arthroplasty without the use of standard arthroscopy portals through an incisionless approach. This technique provides distinct advantages over a more open approach in the setting of a prosthetic joint. Specifically, this technique is useful for a difficult-to-diagnose painful total knee arthroplasty.
Project description:OBJECTIVE:To assess if a coding variant in the gene encoding transient receptor potential cation channel, subfamily V, member 1 (TRPV1) is associated with genetic risk of painful knee osteoarthritis (OA). METHODS:The Ile585Val TRPV1 variant encoded by rs8065080 was genotyped in 3270 cases of symptomatic knee OA, 1098 cases of asymptomatic knee OA and 3852 controls from seven cohorts from the UK, the USA and Australia. The genetic association between the low-pain genotype Ile-Ile and risk of symptomatic and asymptomatic knee OA was assessed. RESULTS:The TRPV1 585 Ile-Ile genotype, reported to be associated with lower thermal pain sensitivity, was associated with a lower risk of symptomatic knee OA in a comparison of symptomatic cases with healthy controls, with an odds ratio (OR) of 0.75 (95% CI 0.64 to 0.88; p=0.00039 by meta-analysis) after adjustment for age, sex and body mass index. No difference was seen between asymptomatic OA cases and controls (OR=1.02, 95% CI 0.82 to 1.27 p=0.86) but the Ile-Ile genotype was associated with lower risk of symptomatic versus asymptomatic knee OA adjusting for covariates and radiographic severity (OR=0.73, 95% CI 0.57 to 0.94 p=0.0136). TRPV1 expression in articular cartilage was increased by inflammatory cytokines (tumour necrosis factor ? and interleukin 1). However, there were no differences in TRPV1 expression in healthy and arthritic synovial tissue. CONCLUSIONS:A genotype involved in lower peripheral pain sensitivity is significantly associated with a decreased risk of painful knee OA. This indicates a role for the pro-nociceptive gene TRPV1 in genetic susceptibility to symptomatic knee OA, which may also be influenced by a role for this molecule in cartilage function.
Project description:PurposeTo investigate the change in patient-reported pain after percutaneous skeletal fixation (PSF) and to determine the success rate of PSF in the prevention of additional intervention for the treatment of painful subchondral bone marrow edema (SBME) of the knee over a 2-year postoperative period.MethodsThis was a retrospective, single-surgeon analysis of patients undergoing PSF for painful, atraumatic SBME of the knee confirmed on preoperative magnetic resonance imaging with a minimum 2-year follow-up. Inclusion criteria were age >18 years, pain localized to the area of edema, failure of nonsurgical intervention (4 weeks of physical therapy and non-steroidal medication use), and absence of tricompartmental Kellgren-Lawrence grade 4 osteoarthritis. All patients underwent arthroscopy, followed by isolated PSF without additional chondral procedures. Pre- and postoperative visual analog scale scores were compared. The primary outcome measure of success was defined as a lack of additional intervention. This included viscosupplementation, corticosteroid injection, or conversion to arthroplasty.ResultsA total of 74 patients with a mean age of 47.2 years and average follow-up time of 38.9 months (range 24-61 months) were evaluated. Successful treatment was noted in 61 patients (82.4%). Of the 13 patients who did not respond to PSF, 5 (6.8%) had been converted to arthroplasty, 11 received viscosupplementation, and 8 required cortisone injections. The average visual analog scale score decreased from 7.55 preoperatively to 3.16 at 2-year follow-up (P < .001). The average body mass index of successfully treated patients (28.2) was significantly less than that of the patients experiencing failure (32.2) (P = .001).ConclusionsPatients undergoing PSF for the treatment of painful SBME may expect a decrease in knee pain and low rates of additional intervention over a 2-year postoperative period.Level of evidenceLevel IV; Therapeutic Case Series.
Project description:Background and aimGrowing attention is being given to utilising physical function measures to better understand and manage knee osteoarthritis (OA). The Fremantle Knee Awareness Questionnaire (FreKAQ), a self-reported measure of body-perception specific to the knee, has never been validated in Italian patients. The aims of this study were to culturally adapt and validate the Italian version of the FreKAQ (FreKAQ-I), to allow for its use with Italian-speaking patients with painful knee OA.MethodsThe FreKAQ-I was developed by means of forward-backward translation, a final review by an expert committee and a test of the pre-final version to evaluate its comprehensibility. The psychometric testing included: internal structural validity by Rasch analysis; construct validity by assessing hypotheses of FreKAQ correlations with the knee injury and osteoarthritis outcome score (KOOS), a pain intensity numerical rating scale (PI-NRS), the pain catastrophising scale (PCS), and the Hospital anxiety and depression score (HADS) (Pearson's correlations); known-group validity by evaluating the ability of FreKAQ scores to discriminate between two groups of participants with different clinical profiles (Mann-Whitney U test); reliability by internal consistency (Cronbach's alpha) and test-retest reliability (intraclass correlation coefficient, ICC2.1); and measurement error by calculating the minimum detectable change (MDC).ResultsIt took one month to develop a consensus-based version of the FreKAQ-I. The questionnaire was administered to 102 subjects with painful knee OA and was well accepted. Internal structural validity confirmed the substantial unidimensionality of the FreKAQ-I: variance explained was 53.3%, the unexplained variance in the first contrast showed an eigenvalue of 1.8, and no local dependence was detected. Construct validity was good as all of the hypotheses were met; correlations: KOOS (rho = 0.38-0.51), PI-NRS (rho = 0.35-0.37), PCS (rho = 0.47) and HADS (Anxiety rho = 0.36; Depression rho = 0.43). Regarding known-groups validity, FreKAQ scores were significantly different between groups of participants demonstrating high and low levels of pain intensity, pain catastrophising, anxiety, depression and the four KOOS subscales (p ≤ 0.004). Internal consistency was acceptable (α = 0.74) and test-retest reliability was excellent (ICC = 0.92, CI 0.87-0.94). The MDC95 was 5.22 scale points.ConclusionThe FreKAQ-I is unidimensional, reliable and valid in Italian patients with painful knee OA. Its use is recommended for clinical and research purposes.
Project description:ObjectiveTo assess short-term efficacy of single intraarticular botulinum toxin (IA-BoNT/A) injection in patients with chronically painful total knee arthroplasty (TKA) in a randomized, placebo-controlled, triple-blind study.MethodsPatients with chronic TKA pain (pain > 6 on 0-10 scale and > 6 months post-TKA) evaluated in and referred from orthopedic surgery clinics were recruited. The primary outcome, proportion of patients with clinically meaningful decrease of at least 2 points on 0-10 visual analog scale (VAS) for pain, was compared between treatment groups at 2 months using comparison of proportions test and for all efficacy timepoints (2, 3, and 4 months) using generalized estimating equations (GEE). Secondary outcomes of global assessment, function, and quality of life were compared using GEE, duration of pain relief by t-test, and adverse events by chi-square test.ResultsIn total, 54 patients with 60 painful TKA were randomized, with main analyses restricted to one TKA per patient (49 TKA in 49 patients). Mean age was 67 years, 84% were men, and mean duration of TKA pain was 4.5 years. A significantly greater proportion of patients (71%) in the IA-BoNT/A group compared to IA-placebo (35%) achieved clinically meaningful reduction in VAS pain at 2 months (p = 0.028) and at all efficacy timepoints (p = 0.019). Duration of meaningful pain relief was significantly greater after IA-BoNT/A, 39.6 days (SD 50.4) compared to IA-placebo, 15.7 days (SD 22.6; p = 0.045). Statistically significantly better scores were seen in IA-BoNT/A vs IA-placebo for all efficacy timepoints for the following outcomes: "very much improved" on physician global assessment of change (p = 0.003); Western Ontario McMaster Osteoarthritis Index physical function (p = 0.026), stiffness (p = 0.004), and total scores (p = 0.024); and Short-Form 36 pain subscale score (p = 0.049). Number of total and serious adverse events was similar between groups, with no patients in either group with new objective motor or sensory deficits during followup.ConclusionIn this single-center randomized trial, single IA-BoNT/A injection provided clinically meaningful short-term improvements in pain, global assessment, and function in patients with chronic painful TKA. A multicenter trial is needed to confirm these findings.
Project description:BackgroundRecently, in an open pilot study, we found up to two years, a potential pain-relieving effect of intra-articular gold micro-particles using the patient's synovial fluid for patients with knee osteoarthritis (KOA). During the study the excluded group of patients, due to multisite pain, co-morbidities, and other exclusion criteria., received intra-articular gold micro-particles using hyaluronic acid,. We aimed to identify if pre-treatment characteristics influence the global outcome two years after intra-articular treatment for painful KOA with gold microparticles using hyaluronic acid.MethodsUsing hyaluronic acid as the carrier, 136 patients with KOA received intraarticular injections with 20 mg gold microparticles (72.000 particles, 20-40 μm in diameter). In the analysis, we included the Global Rating of Change Scale, Pain Detect Questionnaire (PDQ), Body Mass Index (BMI), and Kellgren & Lawrence score at the inclusion, Western Ontario, and McMaster Universities Osteoarthritis Index (WOMAC) sub-scores for pain, stiffness, and function at inclusion and two years.ResultsOn the Global Rating Change Scale, 69.1% of patients reported a positive effect, 28.7% no effect, and 2.2% worse. PDQ and the three WOMAC subscores all improved at two years of follow-up. PDQ ≥ 13 (P = 0.028), BMI (P = 0.022) and Kellgren & Lawrence grade 4 (P = 0.028) at inclusion reduced the effect with a minor odds ratio compared to the baseline effect of treatment (P = 0.025). WOMAC subscores at inclusion did not influence the outcome (P > 0.5).ConclusionsSevere osteoarthritis, obesity, and neuropathic pain, reduced the effect of intra-articular gold microparticles for knee OA.Trial registrationThe study followed the principles of the Declaration of Helsinki and was approved by the local ethics committee of the North Denmark Region by 27/07/2016 (N-20,160,045). The regional data protection agency approved the project by 06/07/2016 (2008-58-0028, ID 2016 - 116) and registered in ClinicalTrial.Gov by 04/01/2018 (NCT03389906).
Project description:ObjectiveThe objective of this study was to investigate subchondral bone turnover at rest and after acute loading using Fluorine-18-labeled sodium fluoride (Na[18F]F) Positron Emission Tomography (PET), in patients with unilateral PFP.DesignTwenty-seven patients with unilateral PFP were recruited from the Institute of Sports Medicine Copenhagen. Participants underwent Na[18F]F-PET imaging before and after a bout of single-leg squats. Bone turnover measures, including mean and maximal standardized uptake value (SUVmean and SUVmax), rate of bone perfusion (K1), rate of tracer uptake into bone (Ki), and extraction fraction of tracer absorbed into bone mineral were assessed for patella and trochlea.ResultsAt rest, the painful knees showed lower SUVmax, K1, and Ki compared to the pain-free knees in the superficial part of the patella. No significant differences were found in the profound part of the patella or trochlea at rest. Following knee loading, the acute increases in SUVmean, SUVmax, Ki and blood flow were reduced in the superficial patella of the painful knees compared to the pain-free knees. In the trochlea, painful knees showed larger increases in SUVmean and Ki in the lateral part, whereas the medial part showed greater increases in K1, Ki, and a larger decrease in extraction fraction after loading.ConclusionPatella displayed decreased bone metabolism at rest and reduced response to loading in the painful versus pain-free knees. Trochlea in the painful knees showed significantly larger increases in subchondral bone metabolism following knee loading compared to the pain-free knees. These novel findings highlight potential differences in bone turnover between the patellar and trochlear regions.
Project description:ObjectiveTo examine the pain-reducing effects of intra-articular oxygen-ozone (O2O3) injections and mechanical focal vibration (mFV) versus O2O3 injections alone in patients with knee osteoarthritis.MethodsPatients with chronic pain (>6 weeks) due to knee osteoarthritis (II-III on the Kellgren-Lawrence scale) were consecutively enrolled and divided into two groups: O2O3 (n = 25) and O2O3-mFV (n = 24). The visual analog scale (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Medical Research Council (MRC) Manual Muscle Testing scale were administered at baseline (before treatment), after 3 weeks of treatment, and 1 month after the end of treatment. Patients received three once-weekly intra-articular injections of O2O3 into the knee (20 mL O3, 20 μg/mL). The O2O3-mFV group also underwent nine sessions of mFV (three sessions per week).ResultsThe VAS score, KOOS, and MRC score were significantly better in the O2O3-mFV than O2O3 group. The within-group analysis showed that all scores improved over time compared with baseline and were maintained even 1 month after treatment. No adverse events occurred.ConclusionAn integrated rehabilitation protocol involving O2O3 injections and mFV for 3 weeks reduces pain, increases autonomy in daily life activities, and strengthens the quadriceps femoris.
Project description:BackgroundBlood flow restriction (BFR) therapy has been proposed to help patients build strength with fewer repetitions than standard physical therapy (PT). We sought to determine if BFR would improve quadriceps and hamstring strength in patients with instability and perceived weakness >1 year after primary total knee arthroplasty (TKA).MethodsWe retrospectively reviewed 48 patients with painful TKAs and flexion instability as well as quadriceps and hamstring weakness who performed a 6-week PT program and received isokinetic strength measurements (ISMs). Thirty-six patients completed a standard PT program (non-BFR) and 12 patients completed a BFR regimen. ISMs were taken before and after PT to quantify quadriceps and hamstring power, torque, and work compared to the contralateral leg. Statistical analysis was conducted on pre-PT and post-PT ISMs and decisions for revision surgery.ResultsThere were no differences in ISMs after PT between the BFR and non-BFR groups. The non-BFR group showed statistically significant strength improvements in flexion but not extension (+28.7%-32.8%, P = .0145-.255). Although no significant difference was found in the BFR group, they saw improvements in all extension strength metrics (19.4%-23.4%, P = .3315-.3901) and flexion (25.7%-29.9%, P = .1994-.2392). No difference was observed between the groups in the rates of subsequent revision TKA (8.3% vs 16.7%, P = .3362).ConclusionBFR did not improve quadriceps and hamstring strength compared to PT alone in patients with instability and weakness after TKA. Over 80% of total patients chose to avoid revision TKA after completion of focused PT with or without BFR.