Accuracy of densitometric vertebral fracture assessment when performed by DXA technicians--a cross-sectional, multiobserver study.

UNLABELLED: Six dual-energy X-ray absorptiometry (DXA) technicians reviewed lateral images of the spine for deformed vertebrae. The images were acquired with a DXA scanner in 235 patients referred for osteoporosis assessment. The outcome was compared to findings on spinal radiographs assessed by two radiologists. Three DXA technicians performed acceptable or better in identifying patients with fractured vertebrae. INTRODUCTION: This is the first study to evaluate the accuracy of vertebral fracture assessment (VFA) when used by DXA technicians as a triage test to select patients with deformed vertebrae for spinal radiographs. METHODS: Lateral single-energy scans and radiographs of the thoracolumbar spine (T4-L4) were acquired in 235 patients aged 65 years or more referred for osteoporosis assessment. Six DXA technicians evaluated lateral scans using dedicated software. The DXA technicians were trained to identify deformed vertebrae, but they did not assess the aetiology of deformity. Two radiologists evaluated the radiographs and their consensus evaluation served as the reference test for vertebral fracture. The main outcome was sensitivity and specificity of the DXA technicians' identification of patients with one or more grade II-III deformities according to Genant's classification. RESULTS: The proportion of patients with one or more grade II-III vertebral fractures was 0.35. Sensitivity ranged from 0.61 to 0.83 and specificity ranged from 0.78 to 0.95 across the DXA technicians. In patients with grade II-III deformities on VFA, the mean probability of one or more grade II-III fractures was 0.74 (range 0.66-0.86). Conversely, in patients without such deformities, the mean probability of grade II-III fractures was 0.14 (range 0.10-0.18). Accuracy was lower for grade I-III deformities for all the DXA technicians. CONCLUSION: Three of six DXA technicians achieved acceptable or better accuracy when using VFA to triage patients with grade II-III vertebral deformities for spinal radiographs. Heterogeneity between DXA technicians appears to be due to differences in subjective thresholds. VFA triage by DXA technicians to identify patients with grade II-III fractures is feasible.

Metabolic and mechanical involvement of arms and legs in simulated double pole skiing.

We evaluated arm and leg work rate and metabolism during double pole ergometer skiing. Thermodilution arm and leg blood flow was determined together with the arterial to venous difference for oxygen, while the work rate was assessed in eight male recreational skiers [24 (SD 7) years]. When work rate increased from 82 (SE 4) to 117 (7) W, leg power increased by 43% (enhanced vertical force and displacement of the body). The elbow angle tended to increase [from 71 (11.3)° to 75 (10.9)°; P = 0.07] and arm oxygen uptake increased by 20 (5)% [from 0.65 (0.07) to 0.78 (0.08) L/min; P < 0.05] because two-arm blood flow increased [from 5.4 (0.6) to 6.3 (0.7) L/min; P < 0.05] with no significant change in oxygen extraction [from 59 (2.3)% to 60 (1.9)%] accompanied with net arm lactate and potassium release. In contrast, two-leg blood flow [from 5.8 (0.5) to 8.0 (0.5) L/min] and oxygen extraction [from 67 (1.3)% to 75 (1.5)%] increased (P < 0.05), resulting in a 53 (8)% increase in leg oxygen uptake [from 0.82 (0.06) to 1.24 (0.07) L/min; P < 0.05]. In conclusion, during double poling on an ergometer, arm muscle metabolism and work rate increase only marginally and an increase in work intensity is covered mainly by the leg muscles.

Preserved metabolic reserve capacity in skeletal muscle of post-infarction heart failure patients.

It has been proposed that exercise capacity during whole body exercise in post-infarction congestive heart failure (CHF) patients is limited by skeletal muscle function. We therefore investigated the balance between cardiopulmonary and muscular metabolic capacity. CHF patients (n=8) and healthy subjects (HS, n=12) were included. Patients with coronary artery disease (CAD, n=8) were included as a control for medication. All subjects performed a stepwise incremental load test during bicycling (∼24 kg muscle mass), two-legged knee extensor (2-KE) exercise (∼4 kg muscle mass) and one-legged knee extensor (1-KE) exercise (∼2 kg muscle mass). Peak power and peak pulmonary oxygen uptake (VO(2peak) ) increased and muscle-specific VO(2peak) decreased with an increasing muscle mass involved in the exercise. Peak power and VO(2peak) were lower for CHF patients than HS, with values for CAD patients falling between CHF patients and HS. During bicycling, all groups utilized 24-29% of the muscle-specific VO(2peak) as measured during 1-KE exercise, with no difference between the groups. Hence, the muscle metabolic reserve capacity during whole body exercise is not different between CHF patients and HS, indicating that appropriately medicated and stable post-infarction CHF patients are not more limited by intrinsic skeletal muscle properties during whole body exercise than HS.

One-legged endurance training: leg blood flow and oxygen extraction during cycling exercise.

AIM: As a consequence of enhanced local vascular conductance, perfusion of muscles increases with exercise intensity to suffice the oxygen demand. However, when maximal oxygen uptake (VO(2)max) and cardiac output are approached, the increase in conductance is blunted. Endurance training increases muscle metabolic capacity, but to what extent that affects the regulation of muscle vascular conductance during exercise is unknown. METHODS: Seven weeks of one-legged endurance training was carried out by twelve subjects. Pulmonary VO(2) during cycling and one-legged cycling was tested before and after training, while VO(2) of the trained leg (TL) and control leg (CL) during cycling was determined after training. RESULTS: VO(2) max for cycling was unaffected by training, although one-legged VO(2) max became 6.7 (2.3)% (mean ± SE) larger with TL than with CL. Also TL citrate synthase activity was higher [30 (12)%; P < 0.05]. With the two legs working at precisely the same power during cycling at high intensity (n = 8), leg oxygen uptake was 21 (8)% larger for TL than for CL (P < 0.05) with oxygen extraction being 3.5 (1.1)% higher (P < 0.05) and leg blood flow tended to be higher by 16.0 (7.0)% (P = 0.06). CONCLUSION: That enhanced VO(2) max for the trained leg had no implication for cycling VO(2) max supports that there is a central limitation to VO(2) max during whole-body exercise. However, the metabolic balance between the legs was changed during high-intensity exercise as oxygen delivery and oxygen extraction were higher in the trained leg, suggesting that endurance training ameliorates blunting of leg blood flow and oxygen uptake during whole-body exercise.

The effect of heavy strength training on muscle mass and physical performance in elite cross country skiers.

AIM: To investigate the effect of supplementing high-volume endurance training with heavy strength training on muscle adaptations and physical performance in elite cross country skiers. Eleven male (18-26 years) and eight female (18-27 years) were assigned to either a strength group (STR) (n=9) or a control group (CON) (n=10). STR performed strength training twice a week for 12 weeks in addition to their normal endurance training. STR improved 1 repetition maximum (RM) for seated pull-down and half squat (19 ± 2% and 12 ± 2%, respectively), while no change was observed in CON. Cross-sectional area (CSA) increased in m. triceps brachii for both STR and CON, while there was no change in the m. quadriceps CSA. VO(2max) during skate-rollerskiing increased in STR (7 ± 1%), while VO(2max) during running was unchanged. No change was observed in energy consumption during rollerskiing at submaximal intensities. Double-poling performance improved more for STR than for CON. Both groups showed a similar improvement in rollerski time-trial performance. In conclusion, 12 weeks of supplemental heavy strength training improved the strength in leg and upper body muscles, but had little effect on the muscle CSA in thigh muscles. The supplemental strength training improved both VO(2max) during skate-rollerskiing and double-poling performance.

Higher skeletal muscular metabolic reserve capacity in COPD patients than healthy subjects.

We investigated the interaction between skeletal muscle exercise capacity and central restrictions using exercise modalities, which recruit differing levels of muscle mass in eight patients chronic obstructive lung disease (COPD) (FEV(1)% of predicted; 35 [SE 4%]) and eight healthy controls. Subjects performed conventional bicycling, two-leg knee extensor (2-KE) and single-leg knee extensor (1-KE) exercises. Maximal values for pulmonary VO(2) (VO(2max)), power output, blood lactate, heart rate, blood pressure, and arterial oxygen saturation of hemoglobin were registered. VO(2max) in controls was 2453 (210), 1468 (124), and 976 (76) mL/min during bicycling, 2-KE and 1-KE, respectively. The COPD patients achieved 48% (P<0.05), 62% (P<0.05), and 81% (P=0.10) of the control values. The mass-specific VO(2max) (VO(2max)/exercising muscle mass) during 1-KE was 345 (25) and 263 (30) mL/kg/min (P<0.05) in controls and COPD patients, respectively. During 2-KE the controls and COPD patients achieved 85% (4%) and 67% (5%) (P=0.06) of the mass-specific VO(2) during 1-KE, while during bicycling they achieved 31% (2%) and 17% (1%) (P<0.05), respectively. The COPD patients have central restrictions when exercising with a relatively small muscle mass (2-KE) and have a higher muscular metabolic reserve capacity than controls during whole body exercise.

The Osteoporosis Self-Assessment Tool versus alternative tests for selecting postmenopausal women for bone mineral density assessment: a comparative systematic review of accuracy.

SUMMARY: We performed a systematic review of studies comparing the Osteoporosis Self-Assessment Tool (OST) and other tests used to select women for bone mineral density (BMD) assessment. In comparative meta-analyses, we found that the accuracy of OST was similar to other tests that are based on information from the medical history. By contrast, assessment by quantitative ultrasonography at the heel was more accurate than OST in discriminating between women with high and low BMD. The methodological quality of the included studies was generally low. INTRODUCTION: Numerous tests are suggested for triaging postmenopausal women for bone mineral density (BMD) assessment by dual-energy X-ray absorptiometry. Previous studies suggest that OST, based on age and weight only, may be as accurate as more complex triage tests. We systematically compare the accuracy of OST and alternative triage tests in postmenopausal women. METHODS: We searched PubMed, Embase, Web of Science, citation lists, and conference proceedings. Our main measure of accuracy was the diagnostic odds ratio (DOR). We compared summary estimates of DOR (sDOR) for OST and alternative tests in pairwise meta-analyses by using the Moses-Littenberg approach. RESULTS: Summary estimates of DOR for OST and the clinical decision rules Simple Calculated Osteoporosis Risk Estimation (SCORE) and Osteoporosis Risk Assessment Instrument (ORAI) did not differ significantly in white women (relative sDOR: 0.57-1.17, all p >or= 0.11). By contrast, sDOR was higher for Stiffness Index assessed by calcaneal quantitative ultrasonography than for OST (relative sDOR: 1.9, p = 0.005). Studies were few in Asian and black women. Methodological quality, assessed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist, was generally low. CONCLUSIONS: In white women, the accuracy of OST and alternative clinical decision rules was similar, whereas Stiffness Index was more accurate than OST. Low study quality renders transferability to clinical settings uncertain.

Performance of the Osteoporosis Self-Assessment Tool in ruling out low bone mineral density in postmenopausal women: a systematic review.

UNLABELLED: The Osteoporosis Self-Assessment Tool (OST) is a simple test that may be of clinical value to rule-out low bone mineral density. We performed a systematic review to assess its performance in postmenopausal women. We included 36 studies. OST performed moderately in ruling-out femoral neck T-score or=0.28). Methodological study quality was generally low. CONCLUSIONS: The clinical usefulness of OST is uncertain. OST could be useful for ruling-out femoral neck T-score

Performance of four clinical screening tools to select peri- and early postmenopausal women for dual X-ray absorptiometry.

Several methods to select postmenopausal women for dual X-ray absorptiometry (DXA) have been proposed. We decided to compare the performance of three clinical decision rules (SCORE, ORAI, OST) with the usual case-finding strategy based on the presence of a major risk factor for future fracture (CFMRF). The study subjects were 2009 healthy, white, peri- or early postmenopausal women participating in the Danish Osteoporosis Prevention Study (DOPS). DXA results expressed as T-scores and scores on SCORE, ORAI, OST and CFMRF were extracted from the DOPS database. First, we evaluated the screening tools as originally described by the developers. The resulting sensitivities and specificities ranged from 18% to 92% and from 66% to 85%, respectively. Only OST achieved a high sensitivity (92%) with respect to femoral neck T-score < or = -2.5; however, the sensitivity with respect to lumbar spine T-score < or = -2.5 was only 51%. Next, the performance of the screening tools was evaluated against T-score < or = -2.0 (and T-score < or = -2.5) in at least one of the regions: femoral neck, total hip or lumbar spine. Using ROC curve analysis, we determined cut-offs yielding sensitivities as close as possible to 90%. The CFMRF and the ORAI tool were too coarse to yield 90% sensitivity. The performances of OST and SCORE were equal from a clinical perspective in that the sensitivities and the specificities varied from 89% to 94% and from 23% to 28%, respectively. The performance of CFMRF was no better than could be expected by chance, yielding a sensitivity of 19% and a specificity of 85%. Applying SCORE or OST 75% of the women would have to be referred for densitometry to identify 90% of the women with T-score < or = -2.0 (or T-score < or = -2.5) in at least one region. In conclusion, our results question the utility of all the evaluated tools for screening peri- and early postmenopausal women for low BMD. However, if a decision on referral has to be made, it may be based on the simple OST rule, which performed as well as or better than any of the other tools.

Simple bone cysts in children treated with methylprednisolone acetate.

Eleven children with simple bone cysts in the proximal humerus metaphysis were treated with intracavity infiltration of methylprednisolone acetate. Nine patients were treated once; the remainder required second injections. Five lesions resolved completely, while six healed sufficiently to eliminate the risk of pathologic fracture, and to permit physical activities without restrictions. Simple bone cysts can be treated satisfactorily with injection of methylprednisolone acetate, thus obviating surgery.

Hematogenous osteomyelitis in children.

In a 10-year period, 31 children, including 9 infants, were treated for hematogenous osteomyelitis. Fifteen children were treated closed and 16 open. Thirteen of 14 positive cultures were Staphylococcus aureus. Three recurrences could possibly have been prevented by a more aggressive primary approach. At follow-up after 5 (1-12) years, 3 neonates had developed severe growth disturbances despite optimal initial treatment. Acceptable results were obtained with antibiotic therapy for 6 weeks or more. We recommend ampicillin and a penicillinase-resistant penicillin, unless bacterial resistance patterns indicate a different antibiotic. We operate if pus has formed and if a child with severe symptoms does not improve during adequate antibiotic treatment and immobilization.

Function after arthrodesis of the knee.

A long-term follow-up of 30 patients with knee arthrodesis, mostly for arthrosis, revealed that 24 were satisfied with the operation, while six were not satisfied, two because of persistent pain. Twenty-three patients were at work at the time of operation, 18 were able to go back to work, while three were allowed disability pensions and two old age pensions. Many patients had problems in attending public performances and in using buses and trains. We conclude that two-thirds of the patients are totally relieved of pain after knee arthrodesis. Most patients accept the stiff joint, some have problems in social life, and a few have to give up working.

The course of pregnancy following spontaneous abortion.

With the aim of being able to advise women concerning a recommended interval between spontaneous abortion and a new pregnancy, the course of pregnancies following spontaneous abortion was studied. Nineteen women conceived within the first 12 weeks. There were no abortions, and 18 pregnancies proceeded normally. Thirty women conceived between 12 and 26 weeks, 29 pregnancies proceeded normally, and none aborted. Forty-two women conceived later than 26 weeks after the abortion. Seven pregnancies terminated in abortion, and 30 proceeded normally. We found no reason to advise women to postpone a new conception after spontaneous abortion.

Stability and motion after traumatic dislocation of the knee.

In a series of 10 patients with traumatic dislocation of the knee joint, closed reduction could be accomplished in nine. Conservative treatment was employed in four and operative repair of the ligaments and capsule in six patients. In two of three patients with complicating artery injury, vascular repair was successful. Above-knee amputation was performed in one patient because of delay in the diagnosis of vascular injury and in another patient because of arteriosclerotic gangrene. At follow-up examination, on average 6 years after the accident, the stability and motion of the knee were evaluated as good in five patients (three operated), fair in two (one operated) and as poor in one operated patient. The conclusions are that good knee function can thus be achieved with both conservative and operative treatment, and that limb salvage depends on prompt diagnosis and treatment of vascular complications.