Effect of foot orthoses vs sham insoles on first metatarsophalangeal joint osteoarthritis symptoms: a randomized controlled trial.

OBJECTIVES: To compare contoured foot orthoses to sham flat insoles for first MTP joint OA walking pain. DESIGN: This was a participant- and assessor-blinded, sham-controlled, multi-centre randomized clinical trial set in community-based private practices. Eighty-eight adults aged ≥45 years with symptomatic radiographic first MTP joint OA were randomized to receive contoured foot orthoses (n = 47) or sham flat insoles (n = 41), worn at all times when wearing shoes for 12 weeks. Primary outcome was change in first MTP joint walking pain (11-point numerical rating scale (NRS), 0-10) over 12 weeks. Secondary outcomes included additional first MTP joint and foot pain measures, physical function, quality of life and physical activity. Separate linear regression models for primary and secondary outcomes on treatment group were fit, adjusting for the outcome at baseline and podiatrist. Other measures included adverse events. RESULTS: 88 participants were randomized and 87 (99%) completed the 12-week primary outcome. There was no evidence foot orthoses were superior to sham insoles for reducing pain (mean difference -0.3 NRS units (95% CI -1.2 to 0.6), p = 0.53). Similarly, foot orthoses were not superior to sham on any secondary outcomes. Sensitivity analyses yielded similar results. Adverse events were generally minor and transient. CONCLUSION: Contoured foot orthoses are no more effective than flat sham insoles for the clinical management of first MTP joint OA. Given the dearth of evidence on treatments for first MTP joint OA, further research is needed to identify effective management approaches for this common and debilitating condition.

Walking-related knee contact forces and associations with knee pain across people with mild, moderate and severe radiographic knee osteoarthritis: a cross-sectional study.

OBJECTIVE: To investigate knee contact forces (KCFs), and their relationships with knee pain, across grades of radiographic knee osteoarthritis (OA) severity. DESIGN: Cross-sectional exploratory analysis of 164 participants with medial knee OA. Radiographic severity was classified as mild (grade 2), moderate (grade 3) or severe (grade 4) using the Kellgren & Lawrence (KL) scale. Walking knee pain was assessed using an 11-point numerical rating scale. External knee adduction moment (external KAM) and internal muscle forces were used to calculate medial, lateral and total KCFs using a musculoskeletal computational model. Force-time series across stance phase of gait were compared across KL grades using Statistical Parametric Mapping. Associations between KCFs and pain across KL grades were assessed using linear models. RESULTS: Medial KCFs during early and middle stance were higher in participants with KL3 and KL4 compared to those with KL2. In contrast, lateral KCFs were higher in those with KL2 compared to KL3 and KL4 in middle to late stance. The external loading component (i.e., KAM) of the medial KCF during middle to late stance was also greater in participants with KL3 and KL4 compared to those with KL2, whereas the internal (i.e., muscle) component was greater in those with KL3 and KL4 compared to KL3 during early stance. There were no associations between medial KCF and knee pain in any KL grade. CONCLUSIONS: Medial and lateral KCFs differ between mild, moderate and severe radiographic knee OA but are not associated with knee pain severity for any radiographic OA grade.

The influence of sex and pre-operative obesity on biomechanics two years after total knee arthroplasty: A longitudinal cohort study.

BACKGROUND: Sex and obesity may influence knee biomechanics associated with poor outcomes following primary total knee arthroplasty (TKA) however their long-term impact has not been investigated. RESEARCH QUESTION: Does sex and/or pre-operative obesity influence change in gait biomechanics from pre-TKA to two-years after TKA, and do knee biomechanics return to normal two-years after TKA? METHODS: In this longitudinal study, gait analysis was performed on 78 patients undergoing TKA for knee osteoarthritis prior to surgery (baseline), and on 66 (85 %) of these who returned at the two year follow-up. Gait biomechanics were also collected on a reference sample of 40 asymptomatic participants. Knee variables were analyzed according to time (pre- and post-TKA), sex (men and women), pre-operative obesity (obese vs non-obese), and group (TKA vs reference). Mixed linear regression models were used to examine the effects of TKA, obesity status, gender and all interactions. RESULTS: There were two-year reductions in peak knee frontal plane angle (mean difference -7.21°; 95% confidence intervals -9.37 to -5.05), peak knee adduction moment (KAM) (-17.64Nm; -23.04 to -12.24) and KAM impulse (-9.40Nm.s; -12.04 to -6.77) in males. These and other variables were unchanged in women. At two years, men exhibited a greater varus-valgus thrust excursion (4.9°; 2.7-7.2), and a lower peak knee frontal plane angle (-4.4°; -7.1 to -1.7) and peak KAM (-13.1Nm; -20.9 to -5.4), compared to the reference sample. Biomechanics at two years did not differ between pre-operative obesity subgroups, or between female TKA patients and the reference sample. SIGNIFICANCE: Changes in gait biomechanics two years after TKA are influenced by sex but not obesity. Men but not women showed altered knee biomechanics two years following TKR and compared to a reference sample. It is unknown whether these altered biomechanics in men impact longer term clinical outcomes and satisfaction following surgery.

Moderators and mediators of effects of unloading shoes on knee pain in people with knee osteoarthritis: an exploratory analysis of the SHARK randomised controlled trial.

OBJECTIVE: To investigate moderators and biomechanical mediators of effects of unloading shoes on knee pain in people with knee osteoarthritis (OA). METHODS: Exploratory analysis from 164 participants in a clinical trial comparing unloading (ASICS GEL-Melbourne OA) to conventional walking shoes. The primary outcome was 6-month change in knee pain (11-point numerical rating scale (NRS)). Moderators included baseline peak knee adduction moment (KAM), radiographic severity (Kellgren & Lawrence (KL) scale), body mass, foot posture, neuropathic pain and diffuse knee pain. Mediators included change in peak KAM and KAM impulse. RESULTS: Radiographic severity was the only moderator to interact with footwear group (P = 0.02). Participants with KL = 2 experienced greater pain reductions with conventional compared to unloading shoes (mean difference in change in pain -1.64 units, 95% CI -3.07, -0.21), while unloading shoes tended to result in greater pain reductions than conventional shoes in KL = 3 (0.98, 95% CI -0.44, 2.39) and KL = 4 (0.64, 95% CI -0.64, 1.93). No variable showed any significant mediating effect in the entire cohort. However, there was some evidence that unloading shoes may reduce pain through reductions in peak KAM (indirect effect -0.31, 95% CIs -0.65, 0.03; P = 0.07) in people with KL ≥ 3, compared to conventional shoes. CONCLUSION: Unloading shoes conferred additional symptomatic benefits over conventional shoes in people with moderate to severe knee OA. There was some evidence effects may be mediated by a reduction in peak KAM. However, we were underpowered for subgroup analyses. These patients may represent a subgroup to which biomechanical interventions designed to reduce the KAM may be more effectively targeted.

Effects of footwear on the knee adduction moment in medial knee osteoarthritis: classification criteria for flat flexible vs stable supportive shoes.

OBJECTIVE: To validate simple criteria that distinguish flat flexible from stable supportive walking shoes by comparing their effects on the knee adduction moment (KAM) in people with medial knee osteoarthritis (OA). DESIGN: This was a cross-sectional biomechanical study. We proposed five criteria to differentiate flat flexible from stable supportive shoes, and selected three pairs of shoes representing each class for biomechanical testing. 28 participants aged ≥50 years with symptomatic medial knee OA underwent gait analysis barefoot and wearing each of the six selected shoes, in random order. Differences in the peak KAM, KAM impulse and peak knee flexion moment (KFM) across test conditions were evaluated with a two-way repeated measures analysis of variance (ANOVA). Immediate changes in walking pain between conditions were also compared. RESULTS: Increases in KAM from barefoot were lower with each of the three flat flexible shoe styles (peak KAM: 6.1-8.9%; KAM impulse: 2.4-5.1%) compared to their stable supportive counterparts (peak KAM: 11.6-15.1%; KAM impulse 10.5-13.2%). There was a significant main effect for footwear class on peak KAM and KAM impulse, whereby stable supportive shoes increased the KAM significantly more than flat flexible shoes (P < 0.001). There were no differences in the KFM or immediate walking pain between footwear classes. CONCLUSIONS: Our proposed criteria can be used by researchers and clinicians to select flat flexible shoes for people with medial knee OA to minimise knee loading. Future research should evaluate whether wearing shoes based on these criteria translates to improvements in knee OA symptoms and/or slows structural disease progression.

The knee adduction moment and knee osteoarthritis symptoms: relationships according to radiographic disease severity.

OBJECTIVE: To investigate relationships between external knee adduction moment parameters (KAM) and osteoarthritis (OA) symptoms according to disease severity. DESIGN: 164 participants with symptomatic medial knee OA were included. Radiographic severity was graded by (1) Kellgren & Lawrence (KL) scale (Grade 2, n = 49; Grade, n = 52; Grade 4, n = 63) and; (2) medial tibiofemoral joint space narrowing (JSN) (Grade 1, n = 47; Grade 2, n = 50; Grade 3, n = 67). KAM-related parameters (peak KAM, KAM impulse and cumulative load) were determined from three-dimensional gait analysis and pedometry. Cumulative load was determined by multiplying KAM impulse by the average number of steps/day recorded over at least 5 days. Symptoms were assessed via numeric rating scale ((NRS), pain) and Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index (pain and physical function). Relationships between KAM parameters (independent variables) and symptoms (dependent variables) were evaluated by radiographic severity using linear models, adjusting for covariates. RESULTS: In mild disease (either KL Grade 2 or JSN Grade 1), there were no associations between KAM and symptoms. In moderate disease of KL Grade 3, higher KAM impulse was associated with greater WOMAC pain. In severe disease (KL Grade 4), higher KAM impulse was associated with less WOMAC pain (KL Grade 4), while higher peak KAM was associated with better function (KL Grade 4). Higher cumulative knee adduction load was associated with less pain on both NRS and WOMAC (JSN Grade 3) as well as better function (both JSN Grade 3 and KL Grade 4). CONCLUSIONS: Relationships between KAM-related parameters and symptoms differ according to underlying radiographic OA severity.

Dynamic knee loading is related to cartilage defects and tibial plateau bone area in medial knee osteoarthritis.

OBJECTIVE: To evaluate the relationship between dynamic mechanical loading, as indicated by external knee adduction moment (KAM) measures during walking, and measures of articular cartilage morphology and subchondral bone size in people with medial knee osteoarthritis (OA). DESIGN: 180 individuals with radiographic medial tibiofemoral OA participated. Peak KAM and KAM angular impulse were measured by walking gait analysis. Tibial cartilage volume and plateau bone area, and tibiofemoral cartilage defects were determined from magnetic resonance imaging using validated methods. RESULTS: Both peak KAM (coefficient=0.42, 95% confidence interval (CI) 0.04-0.79, P=0.03) and KAM impulse (coefficient=1.79, 95% CI 0.80-2.78, P<0.001) were positively associated with the severity of medial tibiofemoral cartilage defects. KAM impulse was also associated with the prevalence of medial tibiofemoral cartilage defects (odds ratio 4.78, 95% CI 1.10-20.76, P=0.04). Peak KAM (B=0.05, 95% CI 0.01-0.09, P=0.02) and KAM impulse (B=0.16, 95% CI 0.06-0.25, P=0.002) were positively associated with medial:lateral tibial plateau bone area, and KAM impulse was also associated with medial tibial plateau bone area (B=133.7, 95% CI 4.0-263.3, P=0.04). There was no significant association between KAM measures and tibial cartilage volume. CONCLUSION: Peak KAM and KAM impulse are associated with cartilage defects and subchondral bone area in patients with medial knee OA, suggesting that increased mechanical loading may play a role in the pathological changes in articular cartilage and subchondral bone that occur with medial knee OA.

Low-intensity pulsed ultrasound for chronic patellar tendinopathy: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Patellar tendinopathy (PT) is a common and significant clinical condition for which there are few established interventions. One intervention that is currently being used clinically to manage PT symptoms is the introduction of low-intensity pulsed ultrasound (LIPUS). The aim of this study was to investigate the clinical efficacy of LIPUS in the management of PT symptoms. METHODS: A randomized, double-blind, placebo-controlled study was conducted. Volunteers with clinically and radiologically confirmed PT were randomly allocated to either an active-LIPUS (treatment) or inactive-LIPUS (placebo) group. LIPUS was self-administered by participants for 20 min/day, 7 days/week for 12 weeks. All participants also completed a daily, standardized eccentric exercise programme based on best practice. Primary outcomes were change in pain during the participant's most aggravating activity in the preceding week, measured on 10 cm visual analogue scales for both usual (VAS-U) and worst (VAS-W) tendon pain. RESULTS: Out of 156 individuals who volunteered, 37 met the eligibility criteria and were randomized to either active-LIPUS (n = 17) or inactive-LIPUS (n = 20). Using an intention-to-treat analysis, VAS-U and VAS-W for the entire cohort decreased by 1.6 +/- 1.9 cm (P < 0.01) and 2.5 +/- 2.4 cm (P < 0.01), respectively. There were no differences between the active- and inactive-LIPUS groups for change in VAS-U (-0.2 cm; 95% CI, -1.5, 1.1 cm) (P = 0.74) or VAS-W (-0.5 cm; 95% CI, -2.1, 1.1 cm) (P = 0.57). A per-protocol analysis provided similar results. CONCLUSIONS: These findings suggest that LIPUS does not provide any additional benefit over and above placebo in the management of symptoms associated with PT.

Efficacy of physiotherapy management of knee joint osteoarthritis: a randomised, double blind, placebo controlled trial.

OBJECTIVE: To determine whether a multimodal physiotherapy programme including taping, exercises, and massage is effective for knee osteoarthritis, and if benefits can be maintained with self management. METHODS: Randomised, double blind, placebo controlled trial; 140 community volunteers with knee osteoarthritis participated and 119 completed the trial. Physiotherapy and placebo interventions were applied by 10 physiotherapists in private practices for 12 weeks. Physiotherapy included exercise, massage, taping, and mobilisation, followed by 12 weeks of self management. Placebo was sham ultrasound and light application of a non-therapeutic gel, followed by no treatment. Primary outcomes were pain measured by visual analogue scale and patient global change. Secondary measures included WOMAC, knee pain scale, SF-36, assessment of quality of life index, quadriceps strength, and balance test. RESULTS: Using an intention to treat analysis, physiotherapy and placebo groups showed similar pain reductions at 12 weeks: -2.2 cm (95% CI, -2.6 to -1.7) and -2.0 cm (-2.5 to -1.5), respectively. At 24 weeks, pain remained reduced from baseline in both groups: -2.1 (-2.6 to -1.6) and -1.6 (-2.2 to -1.0), respectively. Global improvement was reported by 70% of physiotherapy participants (51/73) at 12 weeks and by 59% (43/73) at 24 weeks. Similarly, global improvement was reported by 72% of placebo participants (48/67) at 12 weeks and by 49% (33/67) at 24 weeks (all p>0.05). CONCLUSIONS: The physiotherapy programme tested in this trial was no more effective than regular contact with a therapist at reducing pain and disability.

Balance impairments in individuals with symptomatic knee osteoarthritis: a comparison with matched controls using clinical tests.

OBJECTIVES: To compare balance in individuals with symptomatic knee osteoarthritis (OA) and in age-, gender- and body-mass-matched controls using simple clinical measures. METHODS: Thirty-three people with OA and 33 controls participated. Static postural sway [antero-posterior (AP), lateral and total] was measured using a swaymeter on two different surfaces and under two visual conditions. Dynamic standing balance was assessed using the 'step test'. RESULTS: Both groups displayed similar postural sway on most variables measured. Significantly greater sway was noted in the OA group on a firm surface in both lateral (eyes open) and AP directions (eyes closed), as well as total sway (eyes closed) (P < 0.05). Poorer dynamic standing balance was observed in the OA group as evidenced by the step test (P < 0.0001). CONCLUSIONS: Balance deficits can be identified in the osteoarthritic population using simple, inexpensive measures. However, the clinical relevance of the small deficits identified remains unknown and warrants further investigation.

Discrimination of gamma-hydroxybutyrate and ethanol administered separately and as a mixture in rats.

The physiological effects of gamma-hydroxybutyrate (GHB) are complex and not yet clearly defined. GHB has been labeled as a recreational drug and is reported to be frequently coabused with ethanol (ETH). Other studies have yielded discrepant results as to the interaction between GHB and ETH. Thus, the present study investigated extensively the discriminative stimulus of GHB and ETH and a mixture of the two compounds. Thirty male Long-Evans rats were divided into three groups and trained to discriminate doses of either 300 mg/kg GHB, 1000 mg/kg ETH, or a mixture (MIX: 150 mg/kg GHB+500 mg/kg ETH) from vehicle on a two-lever fixed-ratio (FR) 10 schedule of food reinforcement. Dose-response curves were attained in each group with its respective training drugs. GHB and ETH did not cross-generalize in the ETH- and GHB-trained rats, respectively. However, when the effects of the MIX were tested in the GHB- and ETH-trained rats, a greater than additive response was observed. Testing also revealed that the MIX-trained rats did not perceive a novel stimulus but a near-equal contribution from GHB and ETH. This study provides evidence of a complex relationship between GHB and ETH and opposes previous work reporting cross-generalization between GHB and ETH.