Increased anterior pelvic tilt in patients with acetabular retroversion compared to the general population: A radiographic and prevalence study.

INTRODUCTION: The prevalence of acetabular retroversion is sparsely investigated. It may be associated with increased anterior pelvic tilt. The purpose of this study was to investigate whether patients with symptomatic and radiographically verified acetabular retroversion demonstrated increased anterior pelvic tilt compared to a control group, and furthermore to evaluate the prevalence of acetabular retroversion in the general population. METHODS: Anteroposterior pelvic radiographs in standing position of 111 patients with acetabular retroversion prior to anteverting periacetabular osteotomy (PAO) and 132 matched controls from the general Danish population were assessed. Pelvic tilt was assessed by the sacrococcygeal joint-symphysis distance and pelvic-tilt-ratio. Acetabular retroversion was defined as positive cross-over sign and posterior wall sign. Prior to assessments, interrater reliability analysis was performed. Measurements were agreed by two independent assessors. A nonparametric regression model was used to test between-group differences in median pelvic tilt. The prevalence was calculated as the ratio of subjects and hips with acetabular retroversion, respectively. RESULTS: The patient group had significantly larger median anterior pelvic tilt of 14.3 mm in sacrococcygeal joint-symphysis distance and -0.08 in pelvic-tilt-ratio, compared to controls. The prevalence of subjects in the general population with either unilateral or bilateral acetabular retroversion was 24% and 18% for all hips. CONCLUSION: Our data demonstrated that patients with symptomatic acetabular retroversion have increased anterior pelvic tilt compared to the general population. Radiographic sign of acetabular retroversion was highly prevalent in the general population. IMPLICATION FOR PRACTICE: Increased anterior pelvic tilt should be considered when diagnosing and treating patients with hip pain, as symptoms may be related to the functional position of the pelvis and not necessarily solely come from the radiographic verified acetabular retroversion.

Effects of progressive resistance training prior to total HIP arthroplasty - a secondary analysis of a randomized controlled trial.

OBJECTIVE: To investigate 1-year postoperative effect of preoperative resistance training (RT) in patients undergoing total hip arthroplasty (THA) on patient-reported outcomes on activity and function and objective outcomes on muscle strength and physical performance. DESIGN: A 3-12 months follow-up of a randomized controlled trial. Patients scheduled for THA were randomized into: RT-group, twice a week for 10 weeks prior to THA, or 'care-as-usual' (CG). Primary endpoint of this sequel analysis is HOOS-ADL at 12 months follow-up. Secondary outcome measures are; other HOOS subscales, knee- and hip muscle strength plus function (gait, ascending/descending stairs, and sit-to-stand) at three and/or 12 months. CLINICALTRIALS.GOV: NCT01164111. RESULTS: Eighty patients (70% women, 70.4 ± 7.6 years, BMI of 27.8 ± 4.6) were randomized to RT (n = 40) or CG (n = 40); data from 85% were available at 12 months. No superior effects were observed at 12 months for HOOS ADL (between-group change score [95%CI]) (2.6 [-4.2; 9.8], P = 0.44) or remaining subscales. However, ascending (1.3 s [0.3; 2.3], P = 0.01)) and descending stairs (1.6 s [0.3; 2.9], P = 0.01) demonstrated additional effects. At 3 months clinically relevant change-scores in favour of RT was observed on HOOS-Sport/Rec (10.5 points [1.4; 19.6], P = 0.023), together with higher knee strength of the affected side (14.6 Nm [6.3; 22.9], P < 0.001), and selected outcomes of physical function. CONCLUSIONS: At 12 months after surgery, there was no additional effect of preoperative RT compared with THA alone, but rehabilitation was accelerated at 3 months.

Measures of knee and gait function and radiographic severity of knee osteoarthritis - A cross-sectional study.

BACKGROUND: Pain reports show at most weak to moderate relationship with structural findings of knee osteoarthritis (OA). Less is known about the relationship between measures of knee and gait function and structural findings of knee OA. RESEARCH QUESTION: To test the hypothesis that patient-reported, performance-based and three-dimensional knee and gait measures can distinguish between individuals with varying degrees of radiographic knee OA severity. METHODS: To increase the spectrum of radiographic severity baseline data of individuals included in a cohort study and in a randomized controlled trial respectively were included in this cross-sectional study. Individuals completed the Knee injury and Osteoarthritis Outcome Score (KOOS), Single Limb Mini Squat (SLMS) test, and three-dimensional gait analysis. Radiographic severity was dichotomized into mild (Kellgren Lawrence (KL) 1-2) or severe (KL 3-4) knee OA. Proxies for medial knee joint loading were peak knee adduction moment (KAM) and KAM impulse, and summary measures of overall gait function were the Gait Deviation Index for kinematics (GDI) and kinetics (GDI-kinetic). Area under the receiver operating characteristic curves (AUC) and logistic regressions were used to evaluate whether KOOS-scores, SLMS test, peak KAM, KAM impulse, and GDI-scores could discriminate radiographic severity of knee OA. RESULTS: The sample (n = 115) consisted of 60% women, mean age 61 years (SD 8). Good discriminating abilities (AUC > 0.7) were demonstrated for all measures of knee function and gait, except for GDI and GDI-kinetic (0.62 and 0.36, respectively). Odds ratios from logistic regressions largely supported the AUC findings. SIGNIFICANCE: With the exception of gait summary measures, discriminating abilities were demonstrated by all measures of knee and gait function. Given the interest in interpreting OA as a multi-factorial disease, this information may assist researchers in selecting the most appropriate outcomes for biomechanical studies.

One year effectiveness of neuromuscular exercise compared with instruction in analgesic use on knee function in patients with early knee osteoarthritis: the EXERPHARMA randomized trial.

OBJECTIVE: To test long-term effectiveness of neuromuscular exercise (NEMEX) with instructions in optimized pharmacological treatment (PHARMA) on activities of daily living (ADL) in patients with early knee osteoarthritis. DESIGN: 12-months follow-up from a randomized controlled trial. Participants with mild-to-moderate medial tibiofemoral knee osteoarthritis were randomly allocated to 8 weeks NEMEX or PHARMA. The primary outcome measure was the ADL-subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS). Secondary outcome measures included the other four KOOS-subscales, the University of California Activity Score (UCLA) and the European Quality of Life-5 Dimensions. RESULTS: Ninety-three patients (57% women, 58 ± 8 years, body mass index 27 ± 4 kg/m2) were randomized to NEMEX (n = 47) or PHARMA group (n = 46) with data from 85% being available at 12-months follow-up. Good compliance was achieved for 49% of the participants in NEMEX (≥12 sessions) and 7% in PHARMA (half the daily dose of acetaminophen/NSAIDs ≥ 28 days). Within-group improvements in NEMEX were considered to be clinically relevant (≥10 points) for all KOOS-subscales, except Sport/Rec whereas, no between-groups difference in the primary outcome KOOS ADL (3.6 [-2.1 to 9.2]; P = 0.216) was observed. For KOOS Symptoms, a statistically significant difference of 7.6 points (2.6-12.7; P = 0.004) was observed in favor of NEMEX with 47% improving ≥10 points. CONCLUSIONS: No difference in improvement in difficulty with ADL was observed. NEMEX improved knee symptoms to a greater extent with half of patients reporting clinically relevant improvements. CLINICALTRIALS. GOV IDENTIFIER: NCT01638962 (July 3, 2012). ETHICAL COMMITTEE: S-20110153.

The effect of instruction in analgesic use compared with neuromuscular exercise on knee-joint load in patients with knee osteoarthritis: a randomized, single-blind, controlled trial.

OBJECTIVE: To investigate the effect of a neuro-muscular exercise (NEMEX) therapy program compared with instructions in optimized analgesics and anti-inflammatory drug use (PHARMA), on measures of knee-joint load in people with mild to moderate knee osteoarthritis (OA). We hypothesized that knee joint loading during walking would be reduced by NEMEX and potentially increased by PHARMA. DESIGN: Single-blind, randomized controlled trial (RCT) comparing NEMEX therapy twice a week with PHARMA. Participants with mild-to-moderate medial tibiofemoral knee OA were randomly allocated (1:1) to one of two 8-week treatments. Primary outcome was change in knee load during walking (Knee Index, a composite score from all three planes based on 3D movement analysis) after 8 weeks of intervention. Secondary outcomes were frontal plane peak knee adduction moment (KAM), Knee Injury and Osteoarthritis Outcome Scores (KOOS) and functional performance tests. RESULTS: Ninety three participants (57% women, 58 ± 8 years with a body mass index [BMI] of 27 ± 4 kg/m2 (mean ± standard deviation [SD])) were randomized to NEMEX group (n = 47) or PHARMA (n = 46); data from 44 (94%) and 41 (89%) participants respectively, were available at follow-up. 49% of the participants in NEMEX and only 7% in PHARMA demonstrated good compliance. We found no difference in the primary outcome as evaluated by the Knee Index -0.07 [-0.17; 0.04] Nm/%BW HT. Secondary outcomes largely supported this finding. CONCLUSIONS: We found no difference in the primary outcome; knee joint load change during walking from a NEMEX program vs information on the recommended use of analgesics and anti-inflammatory drugs. ClinicalTrials.gov Identifier: NCT01638962 (July 3, 2012). Ethical Committee: S-20110153.

Changes in knee joint load indices from before to 12 months after arthroscopic partial meniscectomy: a prospective cohort study.

OBJECTIVE: Patients undergoing arthroscopic partial meniscectomy (APM) are at increased risk of knee osteoarthritis (OA). Meniscal damage and/or surgery may alter knee joint loading to increase OA risk. We investigated changes in knee joint loading following medial APM surgery, compared with the contra-lateral leg. METHODS: We estimated indices of knee joint loading (external peak knee adduction moment (KAM), KAM impulse and peak knee flexion moment (KFM)) normalized to body size (i.e., body mass (BM) and height (HT)) using 3D gait analysis in 23 patients (17 men, mean (SD) 46.2 (6.4) years, BMI 25.8 (3.4) kg/m(2)) without radiographic knee OA before and 12 months after medial APM. Static alignment was assessed by radiography and self-reported outcomes by Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: Peak KAM and KAM impulse increased in the APM leg compared to the contra-lateral leg from before to 12 months after surgery (change difference: 0.38 Nm/BM*HT% 95% CI 0.01 to 0.76 (P = 0.049) and 0.20 Nm*s/BM*HT% 95% CI 0.10 to 0.30 (P < 0.001)). Patients self-reported improvements on all KOOS subscales (KOOS pain improvement: 22.8 95% CI 14.5 to 31.0 (P < 0.01)). CONCLUSIONS: A relative increase in indices of medial compartment loading was observed in the leg undergoing APM compared with the contra-lateral leg from before to 12 months after surgery. This increase may contribute to the elevated risk of knee OA in these patients. Randomized trials including a non-surgical control group are needed to determine if changes in joint loading following APM are caused by surgery or by changes in symptoms.

Preoperative progressive explosive-type resistance training is feasible and effective in patients with hip osteoarthritis scheduled for total hip arthroplasty--a randomized controlled trial.

OBJECTIVE: To investigate the efficacy and feasibility of progressive explosive-type resistance training (RT) in patients with osteoarthritis (OA) of the hip scheduled for total hip arthroplasty (THA). METHOD: Randomized controlled trial (1:1) in patients diagnosed with hip OA and scheduled for THA. The intervention group (IG) performed supervised preoperative progressive explosive-type RT twice a week for 10 weeks; four exercises (hip/thigh) performed in three series each (8-12 repetition maximum). The control group (CG) received 'care as usual'. Efficacy was reported as the between-group difference in the Hip Osteoarthritis Outcome Score (HOOS) (primary endpoint; ADL function), and leg muscle power at post intervention follow-up immediate before surgery. Intention-to-treat analyses were performed in a multilevel regression model adjusting for baseline, sex, age and weight. Feasibility was reported as adherence, exercise related pain and adverse effects. Post-surgical follow up will be reported separately. ClinicalTrials.gov registration: NCT01164111. RESULTS: Eighty patients (age 70.4 ± 7.6 years, BMI 27.8 ± 4.6, 52 females (65%) were included. Adherence was high (93%) with acceptable exercise related pain (VAS score ≤ 5) reported in 83% of sessions and no adverse events. Changes in HOOS 'function' was 10.0 points 95%CI [4.7; 15.3] higher in IG compared to CG (P < 0.001). For all the remaining HOOS subscales IG scored significantly better (P < 0.03) and had higher leg extension muscle power (P < 0.0001) compared to CG. CONCLUSION: Progressive explosive-type RT was feasible in the included group of hip OA patients scheduled for THA and resulted in significant improvement in self-reported outcomes and increased leg muscle power.

Concurrent assessments of lower limb loading patterns, mechanical muscle strength and functional performance in ACL-patients--a cross-sectional study.

BACKGROUND: Full recovery in muscle strength and functional performance may not be achieved after ACL-injury. AIM: The aim of this study is to investigate loading patterns during jumping, muscle function and functional performance in ACL-reconstructed patients and to investigate the origin of between-limb asymmetry by means of a 3-dimensional movement analysis. Design is cross-sectional. METHODS: 23 ACL-reconstructed men (27.2±7.5 years, BMI: 25.4±3.2) 27±7 month post-surgery and 25 matched controls (27.2±5.4 years, BMI: 24.1±1.8) were included. Participants performed (i) bilateral and (ii) unilateral counter movement jumps (CMJ). A 3-D movement analysis was performed by a six-camera Vicon MX-system. Subsequently, jump height (JH), knee joint range of motion (ROM), peak and mean sagittal knee moments were analyzed (iii) one-leg maximal jump for distance was performed, and (iv) maximal unilateral isometric knee extensor and flexor strength (MVC) were measured using stabilized dynamometry. RESULTS: No in-between group differences in age or BMI were observed. CMJ: Between-limb asymmetry ratios for ROM differed (p<0.01) between patients and controls in both types of CMJ (96.1% vs. 102.6% and 87.0% vs. 99.9% in bilateral and single-leg CMJs, respectively). Jump for distance: Patients demonstrated greater (p<0.01) asymmetry for jump length (92.9% vs. 98.6%). MVC: Asymmetry in hamstring MVC was greater (p<0.001) for patients than controls (77.4% vs. 101.3%). CONCLUSIONS: ACL-patients showed reduced function of the operated leg~2 years post ACL-reconstruction, especially for hamstring MVC. Hamstrings are important protagonists to the ACL, thus representing a potential risk factor for secondary ACL-rupture and/or osteoarthritis.

Slide-based ergometer rowing: effects on force production and neuromuscular activity.

Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along with synchronous measurement of handle force and rate of force development (RFD). Compared to stationary conditions, slide-based peak force decreased by 76 (57-95) N (mean 95% CI) in males (P < 0.001) and 20 (8-31) N (P < 0.05) in females. Stroke rate increased (+10.7%) and late-phase RFD decreased (-20.7%) in males (P < 0.05). Neuromuscular activity in m. vastus lateralis decreased in the initial drive phase from 59% to 51% of EMG max in males and from 57% to 52% in females (P < 0.01-0.05), while also decreasing in the late recovery phase from 20% to 7% in males and 17% to 7% in females (P < 0.01). Peak force and maximal neuromuscular activity in the shoulder retractors always occurred in the second quartile of the drive phase. In conclusion, peak force and late-phase RFD (males) decreased and stroke rate increased (males) during slide-based compared to stationary ergometer rowing, potentially reducing the risk of overuse injury. Neuromuscular activity was more affected in leg muscles than thoracic muscles by slide-based ergometer rowing.

Objectively measured physical activity in patients with end stage knee or hip osteoarthritis.

BACKGROUND: Patients with lower extremity osteoarthritis (OA) have increased all cause and disease specific mortality compared to the general population and epidemiological data suggests that OA management should include increased physical activity. AIM: To measure physical activity assessed as daily energy expenditure and accumulated steps day-1 in patients with severe OA of the hip or knee and compare with healthy controls. Furthermore, to investigate if gender, age, BMI and affected joint influence measures of physical activity. DESIGN: Cross sectional study. SETTING: Community. POPULATION: Fifty-one patients (49% women, age: 68±5 years, BMI: 28.4±4.6) with severe knee (N.=25) or hip (N.=26) OA scheduled for total joint replacement and 15 healthy population-based controls (53 % women, age: 68±5 years, BMI: 26.9±4.3). METHODS: Subjects wore an accelerometer (SenseWear™ Pro2 Armband) on 5 consecutive days. Time on body, total energy expenditure, average intensity (METS), time being sedentary, time above 3 METS and numbers of steps day(-1) were calculated. RESULTS: Patients had similar daily energy expenditure to controls (2632 vs. 2633 calories per day) but walked on average 29.3% fewer steps day(-1) (6632 vs. 8576 P=0.033). Gender and affected joint (hip or knee) did not influence the results. Age and BMI explained 15.4%-32.7% of the variation in total energy expenditure, average METS, time being sedentary, and steps day(-1). CONCLUSION: The present data indicate a need for interventions improving walking ability in patients with severe hip and knee OA. This need is independent regarding gender and affected joint but higher for older and heavier patients. Simultaneously assessed measures of physical activity gave different results, raising concern about validity of physical activity measures in patients with lower extremity OA and indicating caution when comparing results from studies applying different measures. CLINICAL REHABILITATION IMPACT: It is of potential interest for patients and practitioners that a relative high physical activity is possible for end-stage OA patients since this may reduce the increased all cause and disease specific mortality.

Ergometer rowing with and without slides.

A rowing ergometer can be placed on a slide to imitate 'on-water' rowing. The present study examines I) possible differences in biomechanical and physiological variables of ergometer rowing with and without slides and II) potential consequences on training load during exercise. 7 elite oars-women rowed in a randomized order in a slide or stationary ergometer at 3 predefined submaximal and at maximal intensity. Oxygen uptake was measured and biomechanical variables of the rowing were calculated based upon handle force (force transducer) and velocity/length (potentiometer) of the stroke. Stroke frequency was higher (%-difference between conditions) at each intensity level (1-11.4%, p<0.05) during slide compared to stationary rowing. Furthermore, at the 2 highest intensities a lower mean force (4.7-9.0%, p<0.05) and max force (3.2-10.6%, p<0.05) were observed on the slide ergometer. During maximal rowing no difference was seen in heart rate, mean oxygen uptake and R-value while maximal oxygen deficit was higher (30.8%, p<0.05) during slide rowing. In conclusion the biomechanical load is lower on a slide than on a stationary ergometer. However, as a training tool the slide ergometer seems just as demanding with regard to aerobic energy sources, and for anaerobic sources possibly even higher, compared with the stationary ergometer.

Reproducibility and relationship of single-joint strength vs multi-joint strength and power in aging individuals.

INTRODUCTION: Reliable and sensitive muscle strength/power assessments are essential when evaluating age-related and/or training-induced changes in maximal strength and power. AIM: To investigate the reproducibility and inter-relationship of single-joint isokinetic/isometric leg muscle strength vs multi-joint mechanical muscle function during counter-movement jump (CMJ) in moderately trained aging individuals (age 72.3+/-6.6). RESULTS: The within-subject coefficient of variation (CV(w-s)) for the single-joint test showed good reproducibility (<10%) for quadriceps and hamstring strength (except for hamstring isometric). Plantar flexion demonstrated good to moderate reproducibility (CV(w-s) range: 10.4-17.2%). Excellent to good CV(w-s) (<10%) was observed for all concentric CMJ parameters, except for plantar flexor mean work (CV(w-s)=13%). Eccentric CMJ parameters demonstrated good to moderate reproducibility (CV(w-s) range: 8.1-18.2%). Isokinetic and isometric quadriceps, hamstring and plantar flexor single-joint strength measurements were found to correlate with several CMJ parameters. CONCLUSION: Single-joint and multi-joint strength and power assessment tests of the lower limbs appear to be reproducible in aging individuals. Furthermore, associations between single-joint strength and multi-joint CMJ power and force variables exist. To evaluate functional capacity in elderly people further investigations must be carried out to identify specific power/strength parameters that are most tightly linked to functional performance.