Biomedical subjects

Merja H Arokoski

Publications and source records attributed to Merja H Arokoski.

5 recordsLinked to original sources

PubMed2005

Postural control in male patients with hip osteoarthritis.

Earlier studies have demonstrated that postural control is worse in patients with knee osteoarthritis (OA) than in control subjects, whereas little information is available about the postural control in patients with hip OA. The aim of this study was to investigate the standing balance in different test conditions in men with hip OA and to compare the results with those of age- and sex-matched healthy controls. Twenty-seven volunteers 47-64-year-old men with hip OA and 30 randomly selected, healthy age-matched men were tested using the sensory organisation test (SOT). The center point of force velocity (CPFV (cm/s)) was also determined during one- and two-footed standing. There was no difference between the patients and controls in the SOT test, in the strategy analysis or during one-footed standing. There were no significant differences in CPFV values between the better and worse hip side. Fatiguing exercise had no effect on two-footed CPFV with eyes open, but when the eyes were closed both two and one-footed CPFV values were significantly increased (p<0.01-0.05) in both groups. No differences were found in fatiguing exercise between control and OA subjects with eyes open or closed or in one-footed trials. In OA patient's subjective pain was related to increasing CPFV (p<0.05). In conclusion, the hip OA had no effect on static balance in men.

Humans↗

PubMed2004

Physical function in men with and without hip osteoarthritis.

OBJECTIVES: To assess the subjective joint pain and function and the objective physical function of lower extremities in men with hip osteoarthritis (OA), to compare the results with those from age- and sex-matched controls, and to evaluate the reproducibility of the functional tests. DESIGN: A cross-sectional study. SETTING: Rehabilitation clinic in a university hospital. PARTICIPANTS: Twenty-seven volunteer men (age range, 47-64 y) with hip OA and 30 randomly selected, healthy age-matched men. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, passive range of motion (ROM) of the hip joint measured with a standard goniometer, and physical functioning evaluated with a test battery. RESULTS: The function and the composite scores of the WOMAC correlated (P<.05) with the degree of radiographically estimated severity of OA. The hips of the control subjects were 13% to 52% more flexible (P range, <.0001-.001) than those of the OA patients. The more the hip was deteriorated, the lower the ROM of the hip was in abduction and in both internal and external rotations. The reproducibility of marching on-the-spot and walking up and down stairs was good in both groups, but in other functional tests the reproducibility was poorer. The controls were significantly (P range, <.05-.01) better at marching, ascending and descending stairs, performing a 25-m walk, and in flexion-extension and abduction-adduction movements compared with the hip OA patients. Most of the WOMAC items were significantly (P<.05) related to the performance tests. CONCLUSIONS: The WOMAC and the ROM can be considered useful hip OA indicators. Marching on-the-spot and walking up and down stairs are the most reproducible physical functioning tests and can thus be recommended for use for patients with hip OA.

Cross-Sectional Studies↗

PubMed2004

Estimation of femoral head bone density using magnetic resonance imaging: comparison between men with and without hip osteoarthritis.

Bone changes are thought to be one important etiological element in the pathogenesis of hip osteoarthritis (OA). The magnetic resonance imaging (MRI)-derived T2* relaxation time has been shown to provide information about bone mineral status of the femoral neck. The aim of this study was to test the hypothesis that the MRI-derived T2* relaxation time of the proximal femur in hip OA differs from that seen in healthy subjects. Based on the American College of Rheumatology criteria regarding classification of the OA of the hip, 27 men (aged 47-64 yr) with unilateral or bilateral hip OA and 30 age-matched randomly selected healthy men were studied. Bone mineral density (BMD), bone mineral content (BMC), and bone width of the femoral neck were measured with dual-energy X-ray absorptiometry (DXA). Subsequently, T2* measurements were performed with a 1.5-T scanner (Siemens Magnetom 63SP; Erlangen, Germany). A single 10-mm-thick coronal slice was generated on the femur, with a repetition time of 60 ms and nine echo times (4-20 ms) to derive T2* values. T2* measurements were performed from the different region of interests (ROIs) from the femoral neck and head. T2* relaxation times showed significant negative correlations with BMC, BMD (r = -0.401 to -0.794; p < 0.05-0.001). T2* relaxation time values revealed no significant differences between the groups in the femoral neck and in the head of the femur, whereas it was 12% lower (p < 0.01) in OA subjects than in controls in acetabulum. There were no significant differences in the T2* relaxation time values between the radiographic OA subgroups. Our findings suggest that hip OA is not associated with an increase of BMD in the femoral neck or in the head of the femur.

Absorptiometry, Photon↗

PubMed2002

Comparison of DXA and MRI methods for interpreting femoral neck bone mineral density.

The aim of the study was to improve the practical implementation of the dual X-ray absorptiometry (DXA) by converting the areal bone mineral density BMD (BMD(areal)) to volumetric BMD using magnetic resonance (MR) imaging (MRI) because a failure to control for the femoral neck size can lead to erroneous interpretation of BMD values. We also evaluated the feasibility of MR T2* relaxation time in assessing bone mineral status of the femoral neck. Twenty-eight randomly selected 47- to 64-yr-old healthy men were studied. The men had neither unilateral nor bilateral hip osteoarthritis according to radiographs. Bone width, mineral content (BMC), BMD(areal), and apparent volumetric BMD (BMD(vol)) of the right femoral neck were measured with DXA. The BMD(vol) was calculated by approximating the femoral neck to be cylindrical with a circular cross-section (Vol(dxa)). Volumetric measurements from MR (Vol(mri)) images of the femoral neck were also used to create a BMD measure that was corrected for the femoral neck volume (BMD(mri)). T2* measurements were performed with a 1.5-T scanner (Siemens Magnetom 63SP, Erlangen, Germany). A single 10-mm-thick coronal slice was generated on the femur with a repetition time of 60 ms, and nine echo times (4-20 ms) were used to derive T2* values. Vol(mri) correlated positively (r = 0.828, p < 0.001) with Vol(dxa). However, the Vol(mri) of the femoral neck was 18% lower than the Vol(dxa). Similarly, the BMD(mri) was related to the BMD(vol) (r = 0.737, p < 0.001). Because of the difference in the volumetric measures, the BMD(mri) of the femoral neck was 21% higher than the BMD(vol) (p < 0.001). T2* relaxation time showed a significant negative correlation with BMC, BMD(areal), BMD(vol), and BMD(mri) (r = -0.423 to -0.757, p < 0.05-0.001). In conclusion, these results are evidence that DXA-derived volume approximations by the cylinder with circular cross-section geometry may lead to lower DXA-derived BMD(vol) values, as compared to true MRI-derived volumetric bone mineral density. Thus, the BMD(vol) may not be an accurate method to calculate the true volumetric BMD in the femoral neck. Our results also suggest that the MRI-derived T2* method may be used to approximate the BMD in the proximal femur.

Absorptiometry, Photon↗

PubMed2002

Hip muscle strength and muscle cross sectional area in men with and without hip osteoarthritis.

OBJECTIVE: To study the hip muscle strength and cross sectional area (CSA) in men with hip osteoarthritis (OA) compared to age and sex matched healthy controls. METHODS: Based on the American College of Rheumatology criteria regarding classification of hip OA, 27 men (aged 47-64 yrs) with unilateral or bilateral hip OA and 30 age matched randomly selected healthy male controls were studied. The maximal isometric hip abductor, adductor, flexor, and extensor strength (Nm) at 0 degree of hip flexion in the supine position was determined with a dynamometer. The isokinetic hip flexion and extension strength (peak torque, Nm) was determined using angular velocities of 60 degrees /s and 120 degrees /s. The subjective severity of hip pain was rated by visual analog scale prior to the muscle strength test. CSA of the pelvic and thigh muscles was measured from magnetic resonance images. RESULTS: The reliability of intraclass correlation coefficients for repeated measures of muscle strength varied from 0.70 to 0.94 in controls and from 0.84 to 0.98 in subjects with OA. Hip isometric adductor and abductor strength was 25% and 31% lower (p < 0.001) in OA subjects than in controls, respectively. The hip isometric and isokinetic flexion strength was 18-22% lower (p < 0.01) in OA subjects than in controls, but extension strength did not differ between groups. In OA subjects, the hip flexion and extension isometric and isokinetic strength values were 13-22% lower (p < 0.05) on the more deteriorated side compared to the better side. CSA of the pelvic and thigh muscles did not differ between the groups. However, in OA subjects, the CSA of the pelvic and thigh muscles was 6-13% less (p < 0.05 to < 0.001) on the more severely affected hip compared to the better hip. CONCLUSION: Men with hip OA have significantly lower abduction, adduction, and flexion muscle strength than controls. The decrease of muscle size and hip pain may contribute to the decrease of muscle strength in hip OA. Other possible underlying causes of the muscle weakness need to be studied.

Anatomy, Cross-Sectional↗