Relationship between foot function and medial knee joint loading in people with medial compartment knee osteoarthritis.

BACKGROUND: Dynamic joint loading, particularly the external knee adduction moment (KAM), is an important surrogate measure for the medio-lateral distribution of force across the knee joint in people with knee osteoarthritis (OA). Foot motion may alter the load on the medial tibiofemoral joint and hence affect the KAM. Therefore, this study aimed to investigate the relationship between tibia, rearfoot and forefoot motion in the frontal and transverse planes and the KAM in people with medial compartment knee OA. METHOD: Motion of the knee, tibia, rearfoot and forefoot and knee moments were evaluated in 32 patients with clinically and radiographically-confirmed OA, predominantly in the medial compartment. Pearson's correlation coefficient was used to investigate the association between peak values of tibia, rearfoot and forefoot motion in the frontal and transverse planes and 1st peak KAM, 2nd peak KAM, and the knee adduction angular impulse (KAAI). RESULTS: Lateral tilt of the tibia was significantly associated with increased 1st peak KAM (r = 0.60, p < 0.001), 2nd peak KAM (r = 0.67, p = 0.001) and KAAI (r = 0.82, p = 0.001). Increased peak rearfoot eversion was significantly correlated with decreased 2nd peak KAM (r = 0.59, p < 0.001) and KAAI (r = 0.50, p = 0.004). Decreased rearfoot internal rotation was significantly associated with increased 2nd peak KAM (r = -0.44, p = 0.01) and KAAI (r = -0.38, p = 0.02), while decreased rearfoot internal rotation relative to the tibia was significantly associated with increased 2nd peak KAM (r = 0.43, p = 0.01). Significant negative correlations were found between peak forefoot eversion relative to the rearfoot and 2nd peak KAM (r = -0.53, p = 0.002) and KAAI (r = -0.51, p = 0.003) and between peak forefoot inversion and 2nd peak KAM (r = -0.54, p = 0.001) and KAAI (r = -0.48, p = 0.005). CONCLUSION: Increased rearfoot eversion, rearfoot internal rotation and forefoot inversion are associated with reduced knee adduction moments during the stance phase of gait, suggesting that medial knee joint loading is reduced in people with OA who walk with greater foot pronation. These findings have implications for the design of load-modifying interventions in people with knee OA.

Effectiveness of scalpel debridement for painful plantar calluses in older people: a randomized trial.

BACKGROUND: Plantar calluses are a common cause of foot pain, which can have a detrimental impact on the mobility and independence of older people. Scalpel debridement is often the first treatment used for this condition. Our aim was to evaluate the effectiveness of scalpel debridement of painful plantar calluses in older people. METHODS: This study was a parallel-group, participant- and assessor-blinded randomized trial. Eighty participants aged 65 years and older with painful forefoot plantar calluses were recruited. Participants were randomly allocated to one of two groups: either real or sham scalpel debridement. Participants were followed for six weeks after their initial intervention appointment. The primary outcomes measured were the difference between groups in pain (measured on a 100-mm visual analogue scale) immediately post-intervention, and at one, three and six weeks post-intervention. RESULTS: Both the real debridement and sham debridement groups experienced a reduction in pain when compared with baseline. Small, systematic between-group differences in pain scores were found at each time point (between 2 and 7 mm favoring real scalpel debridement); however, none of these were statistically significant and none reached a level that could be considered clinically worthwhile. Scalpel debridement caused no adverse events. CONCLUSIONS: The benefits of real scalpel debridement for reducing pain associated with forefoot plantar calluses in older people are small and not statistically significant compared with sham scalpel debridement. When used alone, scalpel debridement has a limited effect in the short term, although it is relatively inexpensive and causes few complications. However, these findings do not preclude the possibility of cumulative benefits over a longer time period or additive effects when combined with other interventions. TRIAL REGISTRATION: Australian Clinical Trials Registry (ACTRN012606000176561).

Lower limb biomechanics in individuals with knee osteoarthritis before and after total knee arthroplasty surgery.

We investigated the biomechanical changes that occur in the lower limb following total knee arthroplasty (TKA). Lower limb joint kinematics and kinetics were evaluated in 32 patients before and 12 months following TKA and 28 age-matched controls. Analysis of variance with Bonferroni-adjusted post-hoc tests showed no significant changes in knee joint kinematics and kinetics following TKA despite significant improvements in pain and function. Significant increases in peak ankle plantarflexion and dorsiflexion moments and ankle power generation were observed which may be a compensatory response to impaired knee function to allow sufficient power generation for propulsion. Differences in knee gait parameters may arise as a result of the presence of osteoarthritis and mechanical changes associated with TKA as well as retention of the pre-surgery gait pattern.

Foot kinematics in people with medial compartment knee osteoarthritis.

OBJECTIVES: Foot orthoses are commonly used in the management of knee OA, although the relationship between foot function and knee OA is still unclear. The purpose of the study was to examine foot function during walking in people with and without medial compartment knee OA. METHODS: Motion of the tibia, rearfoot and forefoot in 32 patients with medial compartment knee OA and 28 age-matched control subjects was investigated. Multivariate analysis was used to compare the groups. RESULTS: The knee OA group contacted the ground with a more everted rearfoot, demonstrated greater peak rearfoot eversion and exhibited reduced rearfoot frontal plane range of motion and reduced rearfoot peak inversion. The tibia was more internally rotated and laterally tilted throughout the gait cycle, with reduced peak external rotation. CONCLUSION: People with medial compartment knee OA exhibit altered foot kinematics during gait that are indicative of a less mobile, more everted foot type. The presence and degree of tibial malalignment and the available rearfoot range of motion during walking may affect individual responses to load-altering interventions, such as foot orthoses and footwear modifications. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, www.anzctr.org.au/, ACTRN12608000116325.

Dynamic foot function changes following total knee replacement surgery.

BACKGROUND: Individuals with knee osteoarthritis (OA) have flatter/more pronated feet than those without OA, but it is unclear whether altered foot posture and function are a cause or consequence of knee OA. The purpose of this study was to examine whether changes in foot posture and function occur after realignment of the knee following total knee replacement (TKR). MATERIALS AND METHODS: Nineteen patients with predominantly medial compartment knee OA were tested prior to and 12 months after TKR. The Foot Posture Index (FPI) and Arch Index (AI) were measured as well as motion of the tibia, rearfoot and forefoot using a 3D motion analysis system incorporating a multisegment foot model. RESULTS: There were no significant changes in FPI or AI following TKR, however gait analysis revealed significant increases in tibial external rotation (-18.7 ± 7.0° vs -22.5 ± 8.7°, p=0.002), tibial transverse plane range of motion (-9.1 ± 4.6° vs -11.4 ± 6.1°, p=0.0028) and rearfoot range of motion in the frontal plane (8.6 ± 2.6° vs 10.4 ± 2.7°, p=0.002), and a decrease in rearfoot transverse plane range of motion (8.7 ± 5.3° vs 5.9 ± 4.1°, p=0.038) following the procedure. CONCLUSIONS: TKR produces no change in static foot posture, but results in significant changes in rearfoot kinematics during gait. These findings suggest that rearfoot motion compensates for changes in the alignment of the knee, highlighting the ability of the foot to accommodate for proximal skeletal malalignment.

Ultrasound guided corticosteroid injection for plantar fasciitis: randomised controlled trial.

OBJECTIVE: To investigate the effectiveness of ultrasound guided corticosteroid injection in the treatment of plantar fasciitis. DESIGN: Randomised, investigator and participant blinded, placebo controlled trial. SETTING: University clinic in Melbourne, Australia. PARTICIPANTS: 82 people with a clinical and ultrasound diagnosis of plantar fasciitis unrelated to systemic inflammatory disease. INTERVENTIONS: Participants were randomly allocated to ultrasound guided injection of the plantar fascia with either 1 mL of 4 mg/mL dexamethasone sodium phosphate (experimental group) or 1 mL normal saline (placebo). Before injection the participants were given an ultrasound guided posterior tibial nerve block with 2% lidocaine (lignocaine). MAIN OUTCOME MEASURES: Primary outcomes were pain, as measured by the foot health status questionnaire (0-100 point scale), and plantar fascia thickness, measured by ultrasound at 4, 8, and 12 weeks. RESULTS: Reduction in pain at four weeks favoured the dexamethasone group by 10.9 points (95% confidence interval 1.4 to 20.4, P=0.03). Between group differences for pain scores at eight and 12 weeks were not statistically significant. Plantar fascia thickness measured at four weeks favoured the dexamethasone group by -0.35 mm (95% confidence interval -0.67 to -0.03, P=0.03). At eight and 12 weeks, between group differences for plantar fascia thickness also favoured dexamethasone, at -0.39 mm (-0.73 to -0.05, P=0.02) and -0.43 mm (-0.85 to -0.01, P=0.04), respectively. The number needed to treat with dexamethasone for one successful outcome for pain at four weeks was 2.93 (95% confidence interval 2.76 to 3.12). There were no reported adverse events associated with the intervention. CONCLUSION: A single ultrasound guided dexamethasone injection is a safe and effective short term treatment for plantar fasciitis. It provides greater pain relief than placebo at four weeks and reduces abnormal swelling of the plantar fascia for up to three months. However, clinicians offering this treatment should also note that significant pain relief did not continue beyond four weeks. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12610000239066.

Swing limb mechanics and minimum toe clearance in people with knee osteoarthritis.

OBJECTIVE: Knee osteoarthritis (OA) has been shown to be a risk factor for falls. Reductions in foot clearance during the swing phase of walking can cause a trip and potentially lead to a fall. This study examined the swing phase mechanics of people with and without knee OA during walking. DESIGN: Minimum toe clearance (MTC) height, joint angles at the time of MTC and the influence of the angular changes of the hip, knee and ankle of the swing leg on foot clearance using sensitivity analysis were investigated in 50 knee OA participants and 28 age-matched asymptomatic controls. RESULTS: Although both groups had a similar MTC height (controls: 12.8±6.7 mm, knee OA: 13.4±7.0 mm), the knee OA group used a different strategy to achieve the same foot clearance, as evidenced by greater knee flexion (52.5±5.3° vs 49.4±4.8°, p=0.007), greater hip abduction (-3.6±3.3° vs -1.8±3.3°, p=0.03) and less ankle adduction (2.8±1.9° vs 4.2±2.1°, p=0.01). CONCLUSION: MTC height was comparable between the groups, however a different swing phase mechanism was used by the knee OA. Although adequate MTC is an important component of safe locomotion, it does not appear to be impaired in people with knee OA. Other factors, such as inadequate responses to postural perturbation, may be responsible for falls in this group.

Lower limb proprioception deficits persist following knee replacement surgery despite improvements in knee extension strength.

PURPOSE: Knee pain and disability can persist following knee replacement surgery which may place patients at increased risk of falls. This study investigated the falls risk and the occurrence of falls of people with knee osteoarthritis (OA) before and at 12 months following knee replacement surgery. METHOD: Thirty-five patients with knee OA were tested prior to undergoing knee replacement surgery and at 12 months following surgery using the short form Physiological Profile Assessment, which incorporates tests of vision, lower limb proprioception, knee extension strength, reaction time and postural sway. Physical activity, number of falls, fear of falling, pain, disability and health-related quality of life were also assessed. RESULTS: No significant differences were found between the number of falls pre- and post-surgery (n.s.), with 48.5 and 40% reporting at least one fall in the 12 months before and following the surgery, respectively. Improvements in knee strength, reaction time and fear of falling were evident following surgery, with no improvement in lower limb proprioception. Self-reported pain, function and stiffness were significantly improved, but health-related quality of life deteriorated following the surgery. CONCLUSION: The number of falls experienced following knee replacement surgery remained relatively high, which may be attributed to the persistence of impaired lower limb proprioception. Although knee replacement surgery improves function and alleviates pain, people who undergo this procedure may need to engage in rehabilitation following the surgery to reduce the risk of falling. LEVEL OF EVIDENCE: Therapeutic study investigating the result of treatment on patient outcomes, Level IV.

Knee biomechanics early after knee replacement surgery predict abnormal gait patterns 12 months postoperatively.

An abnormal flexor moment pattern is often evident following total knee replacement (TKR) surgery. We investigated whether such a pattern at 12 months post-surgery could be predicted using biomechanical gait measures assessed before surgery and at 4 months post-surgery. Thirty two TKR patients were evaluated and classified as normal (biphasic pattern) or abnormal (flexor moment pattern) at each time point. Biomechanical parameters collected before surgery and at 4 months post-surgery were then explored for their ability to predict gait patterns at 12 months post-surgery. The gait pattern at 4 months was significantly associated with the 12 month post-surgery gait pattern, with over half of those with a flexor moment pattern at 4 months retaining this pattern at 12 months. Discriminant function analysis indicated that peak knee flexion during early stance, peak knee extension, and peak knee extension moment at 4 months post-surgery were independent predictors of the gait pattern at 12 months. Thus, an abnormal knee flexor moment pattern at 12 months post-surgery can be predicted by biomechanical analysis 4 months after surgery. Therefore, interventions aimed at improving active extension may need to be implemented early after surgery to restore a normal gait pattern.

Ultrasound guided injection of dexamethasone versus placebo for treatment of plantar fasciitis: protocol for a randomised controlled trial.

BACKGROUND: Plantar fasciitis is the most commonly reported cause of chronic pain beneath the heel. Management of this condition commonly involves the use of corticosteroid injection in cases where less invasive treatments have failed. However, despite widespread use, only two randomised trials have tested the effect of this treatment in comparison to placebo. These trials currently offer the best available evidence by which to guide clinical practice, though both were limited by methodological issues such as insufficient statistical power. Therefore, the aim of this randomised trial is to compare the effect of ultrasound-guided corticosteroid injection versus placebo for treatment of plantar fasciitis. METHODS: The trial will be conducted at the La Trobe University Podiatry Clinic and will recruit 80 community-dwelling participants. Diagnostic ultrasound will be used to diagnose plantar fasciitis and participants will be required to meet a range of selection criteria. Participants will be randomly allocated to one of two treatment arms: (i) ultrasound-guided injection of the plantar fascia with 1 mL of 4 mg/mL dexamethasone sodium phosphate (experimental group), or (ii) ultrasound-guided injection of the plantar fascia with 1 mL normal saline (control group). Blinding will be applied to participants and the investigator performing procedures, measuring outcomes and analysing data. Primary outcomes will be pain measured by the Foot Health Status Questionnaire and plantar fascia thickness measured by ultrasound at 4, 8 and 12 weeks. All data analyses will be conducted on an intention-to-treat basis. CONCLUSION: This will be a randomised trial investigating the effect of dexamethasone injection on pre-specified treatment outcomes in people with plantar fasciitis. Within the parameters of this protocol, the trial findings will be used to make evidence-based recommendations regarding the use of corticosteroid injection for treatment of this condition. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry. ACTRN12610000239066.