Loss of bone in the proximal part of the femur following unstable fractures of the leg

Physical Activity and Sedentary Behavior 6 Months After Musculoskeletal Trauma: What Factors Predict Recovery?

BACKGROUND

Physical activity is increasingly recognized as an important marker of functional recovery following fracture.

OBJECTIVE

The objectives of this study were to measure sedentary behavior and physical activity 2 weeks and 6 months following fracture and to determine associated demographic and injury factors.

DESIGN

This was an observational study.

METHODS

Two weeks and 6 months following fracture, 83 adults who were 18 to 69 years old and had upper limb (UL) or lower limb (LL) fractures wore an accelerometer and an inclinometer for 10 days. We calculated sitting time, steps, moderate-intensity physical activity (MPA), and vigorous-intensity physical activity and conducted linear mixed-effects multivariable regression analyses to determine factors associated with temporal changes in activity.

RESULTS

At 6 months versus 2 weeks after fracture, participants sat less, took more steps, and engaged in more MPA. Participants with LL fractures sat 2 hours more, took 66% fewer steps, and engaged in 77% less MPA than participants with UL fractures. Greater reductions in sitting time were observed for participants in the youngest age group and with LL fractures, participants with high preinjury activity, and participants who were overweight or obese. For steps, greater improvement was observed for participants in the youngest and middle-aged groups and those with LL fractures. For MPA, greater improvement was observed for middle-aged participants and those with LL fractures.

LIMITATIONS

Although this study was sufficiently powered for the analysis of major categories, a convenience sample that may not be representative of all people with musculoskeletal trauma was used.

CONCLUSIONS

Working-age adults with LL fractures had lower levels of physical activity 6 months after fracture than those with UL fractures. Older adults showed less improvement over time, suggesting that they are an important target group for interventions aimed at regaining preinjury activity levels.

Time dependent loss of trabecular bone in human tibial plateau fractures

We investigated if time between injury and surgery affects cancellous bone properties in patients suffering tibial plateau fractures (TPF), in terms of structural integrity and gene expression controlling bone loss. A cohort of 29 TPF, operated 1-17 days post-injury, had biopsies from the fracture and an equivalent contralateral limb site, at surgery. Samples were assessed using micro-computed tomography and real-time RT-PCR analysis for the expression of genes known to be involved in bone remodeling and fracture healing. Significant decreases in the injured vs control side were observed for bone volume fraction (BV/TV, -13.5 ± 6.0%, p = 0.011), trabecular number (Tb.N, -10.5 ± 5.9%, p = 0.041) and trabecular thickness (Tb.Th, -4.6 ± 2.5%, p = 0.033). Changes in these parameters were more evident in patients operated 5-17 days post-injury, compared to those operated in the first 4 days post-injury. A significant negative association was found between Tb.Th (r = -0.54, p < 0.01) and BV/TV (r = -0.39, p < 0.05) in relation to time post-injury in the injured limb. Both BV/TV and Tb.Th were negatively associated with expression of key molecular markers of bone resorption, CTSK, ACP5, and the ratio of RANKL:OPG mRNA. These structure/gene expression relationships did not exist in the contralateral tibial plateau of these patients. This study demonstrated that there is a significant early time-dependent bone loss in the proximal tibia after TPF. This bone loss was significantly associated with altered expression of genes typically involved in the process of osteoclastic bone resorption but possibly also bone resorption by osteocytes. The mechanism of early bone loss in such fractures should be a subject of further investigation. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2865-2875, 2018.

Disuse osteopenia following leg fracture in postmenopausal women: Implications for HIP fracture risk and fracture liaison services

INTRODUCTION

Disuse osteopenia is a known consequence of reduced weight-bearing and has been demonstrated at the hip following leg injury but has not been specifically studied in postmenopausal women.

METHOD

Bilateral DXA (GE Lunar Prodigy) bone mineral density (BMD) measurements were taken at the neck of femur (NOF), total hip region (TH) and lumbar spine in postmenopausal female groups comprising controls (N = 43), new leg fractures (#<3wks) (N = 9), and participants who had sustained a leg fracture more than one year previously (#>1yr) (N = 24). #>1yr were assessed at a single visit and the remaining groups at intervals over twelve months. Weight-bearing, function, 3-day pedometer readings, and pain levels were also recorded.

RESULTS

The #<3wks demonstrated significant (p < 0.05) losses in ipsilateral TH BMD at 6 weeks from baseline 0.927 ± 0.137 g/cm², to 0.916 ± 0.151 g/cm² improving to 0.946 ± 0.135 g/cm² (n.s) at 12 months following gradual return to normal function and weight-bearing activity. The #>1yr scored significantly below controls in almost all key physical and functional outcomes demonstrating a long-term deficit in hip bone density on the ipsilateral side.

CONCLUSION

The clinical significance of post-fracture reduction in hip BMD is a potential increased risk of hip fracture for a variable period that may be mitigated after return to normal function and weight-bearing. Improvement at 12 months in #<3wks is not consistent with #>1yr results indicating that long-term impairment in function and bone health may persist for some leg fracture patients. Unilateral bone loss could have implications for Fracture Liaison Services when assessing the requirement for medication post fracture.

The effect of time to post-operative weightbearing on functional and clinical outcomes in adults with a displaced intra-articular calcaneal fracture; A systematic review and pooled analysis

BACKGROUND

Post-operative weightbearing guidelines for displaced intra-articular calcaneal fractures (DIACF) have been pragmatically developed in the past, however hardly adapted to current health care insights. A period of six to nine weeks of non-weightbearing is usually recommended. It is unknown whether an earlier start of weightbearing is advisable.

OBJECTIVES

The primary aim was to evaluate the effect of time to post-operative weightbearing on Böhler's angle. Secondary aims were to determine the effect on functional outcome (e.g., The American Orthopedic Foot and Ankle Society Scale), post-operative pain score, complications (e.g., infections, nonunion, implant removal), and revision surgeries. Finally, the effect of bone void filling on these outcomes was investigated.

DATA SOURCE

A literature search was performed on January 24, 2017 in the Cochrane Library, Medline Ovid, Embase, Web of Science, Google Scholar, and CINAHL.

LITERATURE SELECTION

Studies reporting on operatively treated patients with a DIACF and time to weightbearing were eligible for inclusion. Studies were excluded when not reporting primary data, solely reporting on open fractures, bilateral fractures, or polytrauma patients. Based upon the time to starting partial weightbearing, patient cohorts were stratified into very early (0-4 weeks), early (4-6 weeks), intermediate (6-8 weeks), or late (8-12 weeks) start of partial weightbearing.

DATA EXTRACTION

Two investigators extracted data independently using a predefined data sheet.

RESULTS

After applying exclusion criteria, 72 studies remained eligible for analysis. Böhler's and Gissane's angles, calcaneal height, AOFAS, pain scores, and complications had overlapping confidence intervals in all weightbearing groups.

CONCLUSION

The adverse sequelae which are assumed to be associated with starting partial weightbearing already within six weeks after internal fixation of calcaneal fractures, is not supported by literature data. This systematic review suggests that early weightbearing does not result in impaired outcomes compared with more conservative weightbearing regimes.

Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures

BACKGROUND

Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback on weight bearing in individuals with lower extremity fractures in two conditions: full weight bearing and touch-down weight bearing.

METHODS

11 participants with full weight bearing and 12 participants with touch-down weight bearing after lower extremity fractures have been measured with an ambulatory biofeedback system. The participants first walked 15m and the biofeedback system was only used to register the weight bearing. The same protocol was then repeated with real-time visual feedback during weight bearing. The participants could thereby adapt their loading to the desired level and improve therapy compliance.

RESULTS

In participants with full weight bearing, real-time visual biofeedback resulted in a significant increase in loading from 50.9±7.51% bodyweight (BW) without feedback to 63.2±6.74%BW with feedback (P=0.0016). In participants with touch-down weight bearing, the exerted lower extremity load decreased from 16.7±9.77kg without feedback to 10.27±4.56kg with feedback (P=0.0718). More important, the variance between individual steps significantly decreased after feedback (P=0.018).

CONCLUSIONS

Ambulatory monitoring weight bearing after lower extremity fractures showed that therapy compliance is low, both in full and touch-down weight bearing. Real-time visual biofeedback resulted in significantly higher peak loads in full weight bearing and increased accuracy of individual steps in touch-down weight bearing. Real-time visual biofeedback therefore results in improved therapy compliance after lower extremity fractures.

Effect of Teriparatide or Risedronate in Elderly Patients With a Recent Pertrochanteric Hip Fracture: Final Results of a 78-Week Randomized Clinical Trial

We present final results of a study comparing teriparatide 20 μg every day (QD) with risedronate 35 mg once per week (QW) started within 2 weeks after surgery for a pertrochanteric hip fracture. Patients with BMD T-score ≤ -2.0 and 25OHD ≥9.2 ng/mL were randomized to receive 26-week double-dummy treatment plus calcium and vitamin D, followed by 52-week open-label treatment with the same assigned active drug. Primary endpoint was change from baseline in lumbar spine (LS) BMD at 78 weeks. Secondary and exploratory endpoints were change in BMD at the proximal femur, function, hip pain (Charnley score and 100 mm Visual Analog Scale [VAS]), quality of life (Short Form-36), radiology outcomes, and safety. Data were analyzed with mixed models for repeated measures (MMRM) and logistic regression. Totally, 224 patients were randomized; 171 (teriparatide: 86) contributed to the efficacy analyses (mean ± SD age: 77 ± 7.7 years, 77% females). Mean baseline LS, femoral neck (FN), and total hip (TH) T-scores were -2.16, -2.63, and -2.51, respectively. At 78 weeks, BMD increased significantly more with teriparatide compared to risedronate at the LS (+11.08% versus +6.45%; p < 0.001) and FN (+1.96% versus -1.19%; p = 0.003), with no significant between-group difference in TH BMD. Timed up-and-go (TUG) test was significantly faster with teriparatide at 6, 12, 18, and 26 weeks (differences: -3.2 to -5.9 s; p = 0.045 for overall difference). Hip pain during TUG test by 100 mm VAS was significantly lower with teriparatide at 18 weeks (adjusted difference: -11.3 mm, p = 0.033; -10.0 and -9.3 mm at 12 and 26 weeks, respectively; p = 0.079 for overall difference). Other secondary and exploratory outcomes were not different. Teriparatide group showed two new hip fractures versus seven with risedronate (p = 0.171) and more frequent hypercalcemia and hyperuricemia. In conclusion, 78-week treatment with teriparatide showed significantly greater increases in LS and FN BMD, less pain, and a faster TUG test versus risedronate. © 2016 American Society for Bone and Mineral Research.

Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson's disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

Factors affecting bone mineral mass loss after lower-limb fractures in a pediatric population

BACKGROUND

The purpose of this study was to assess the effects of the durations of cast immobilization and non-weight-bearing periods, and decreases in vigorous physical activity (VPA) on bone mineral parameters in a pediatric population treated for a lower-limb fracture.

METHODS

Fifty children and teenagers who had undergone a cast-mediated immobilization for a leg or ankle fracture were prospectively recruited. The durations of cast immobilization and non-weight-bearing periods were recorded for each participant. Dual-energy x-ray absorptiometry scans were performed at the time of fracture treatment (baseline) and at cast removal. Physical activity during cast immobilization was assessed using accelerometers.

RESULTS

A strong negative correlation was found between the total duration of cast immobilization and decreases in both calcaneal bone mineral density (BMD) (r=-0.497) and total lower-limb bone mineral content (BMC) (r=-0.405). A strong negative correlation was also noted between the durations of the non-weight-bearing periods and alterations in calcaneal BMD (r=-0.420). No apparent correlations were found between lower BMD and BMC and decreased VPA.

CONCLUSIONS

Bone mineral loss was correlated to the total duration of cast immobilization for all measurement sites on the affected leg, whereas it was only correlated to the durations of non-weight-bearing periods for calcaneal BMD and total lower-limb BMC. However, no correlations were noted between bone mineral loss and decreased VPA.

Low bone mineral density is not related to failure in femoral neck fracture patients treated with internal fixation

BACKGROUND AND PURPOSE

Internal fixation (IF) in femoral neck fractures has high reoperation rates and some predictors of failure are known, such as age, quality of reduction, and implant positioning. Finding new predictors of failure is an ongoing process, and in this study we evaluated the importance of low bone mineral density (BMD).

PATIENTS AND METHODS

140 consecutive patients (105 females, median age 80) treated with IF had a dual-energy X-ray absorptiometry (DXA) scan of the hip performed median 80 days after treatment. The patients' radiographs were evaluated for fracture displacement, implant positioning, and quality of reduction. From a questionnaire completed during admission, 2 variables for comorbidity and walking disability were chosen. Primary outcome was low hip BMD (amount of mineral matter per square centimeter of hip bone) compared to hip failure (resection, arthroplasty, or new hip fracture). A stratified Cox regression model on fracture displacement was applied and adjusted for age, sex, quality of reduction, implant positioning, comorbidity, and walking disability.

RESULTS

49 patients had a T-score below -2.5 (standard deviation from the young normal reference mean) and 70 patients had a failure. The failure rate after 2 years was 22% (95% CI: 12-39) for the undisplaced fractures and 66% (CI: 56-76) for the displaced fractures. Cox regression showed no association between low hip BMD and failure. For the covariates, only implant positioning showed an association with failure.

INTERPRETATION

We found no statistically significant association between low hip BMD and fixation failure in femoral neck fracture patients treated with IF.

Recovery of decreased bone mineral mass after lower-limb fractures in adolescents

BACKGROUND

Loss of bone mineral mass, muscle atrophy, and functional limitations are predictable consequences of immobilization and subsequent weight-bearing restriction due to leg or ankle fractures. The aim of this study was to prospectively determine whether decreased bone mineral mass following lower-limb fractures recovers at follow-up durations of six and eighteen months in adolescents.

METHODS

In the present study, we included fifty adolescents who underwent cast immobilization for a leg or ankle fracture. Dual x-ray absorptiometry scans of four different sites (total hip, femoral neck, entire lower limb, and calcaneus) were performed at the time of the fracture, at cast removal, and at follow-ups of six and eighteen months. Patients with fractures were paired with healthy controls according to sex, age, and ethnicity. Dual x-ray absorptiometry values were compared between groups and between injured and non-injured legs in adolescents with fractures.

RESULTS

Among those with fractures, lower-limb bone mineral variables were significantly lower at the injured side compared with the non-injured side at cast removal, with differences ranging from 6.2% to 31.7% (p &lt; 0.0001). Similarly, injured adolescents had significantly lower bone mineral values at the level of the injured lower limb compared with healthy controls (p &lt; 0.0001). At the six-month follow-up, there were still significant residual differences between injured and non-injured legs in adolescents with fractures (p &lt; 0.0001). However, a significant residual difference between healthy controls and injured adolescents was present only for femoral neck bone mineral density (p = 0.011). At the eighteen-month follow-up, no significant difference was observed at any lower-limb site.

CONCLUSIONS

Bone mineral loss following a fracture of the lower limb in adolescents is highly significant and affects the lower limb both proximal to and distal to the fracture site. In contrast to observations in adults, a rapid bone mass reversal occurs with full bone recovery by eighteen months.

LEVEL OF EVIDENCE

Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Effects of cast-mediated immobilization on bone mineral mass at various sites in adolescents with lower-extremity fracture

BACKGROUND

Leg or ankle fractures occur commonly in the pediatric population and are primarily treated with closed reduction and cast immobilization. The most predictable consequences of immobilization and subsequent weight-bearing restriction are loss of bone mineral mass, substantial muscle atrophy, and functional limitations. The purposes of this study were to determine if lower-limb fractures in adolescents are associated with abnormal bone mineral density or content at the time of fracture, and to quantify bone mineral loss at various sites due to cast-mediated immobilization and limited weight-bearing.

METHODS

We recruited fifty adolescents aged ten to sixteen years who had undergone cast immobilization for a leg or ankle fracture. Dual x-ray absorptiometry scans of the total body, lumbar spine, hip, leg, and calcaneus were performed at the time of fracture and at cast removal. Patients with a fracture were paired with healthy controls according to sex and age. Values at baseline and at cast removal, or at equivalent time intervals in the control group, were compared between groups and between the injured and uninjured legs of the adolescents with the fracture.

RESULTS

At the time of fracture, there were no observed differences in the bone mineral density or bone mineral content Z-scores of the total body or the lumbar spine, or in the bone mineral density Z-scores of the calcaneus, between the injured and healthy subjects. At cast removal, bone mineral parameters on the injured side were significantly lower than those on the uninjured side in the injured group. Differences ranged from -5.8% to -31.7% for bone mineral density and from -5.2% to -19.4% for bone mineral content. During the cast period, the injured adolescents had a significant decrease of bone mineral density at the hip, greater trochanter, calcaneus, and total lower limb as compared with the healthy controls.

CONCLUSIONS

Lower-limb fractures are not related to osteopenia in adolescents at the time of fracture. However, osteopenia does develop in the injured limb during cast immobilization for fracture treatment. Further investigation is required to determine if the bone mineral mass will return to normal or if a permanent decrease is to be expected, which may constitute a hypothetical risk of sustaining a second fracture.

Changes in bone metabolism in a rat model of traumatic brain injury

PRIMARY OBJECTIVE

To evaluate the process of bone metabolism after traumatic brain injury.

RESEARCH DESIGN

Randomized controlled trial.

METHODS AND PROCEDURES

Rats were randomly assigned to either the brain injury group or to the sham-operation group using a fluid percussion device. The BMDs of lumbar vertebrae and proximal femur and bone turnover markers, osteocalcin and carboxy-terminal telopeptide, were measured at three points: the day before surgery and 1 and 3 weeks post-operatively. The biomechanics (maximum load of tibia and femoral neck) were measured 3 weeks post-operatively.

MAIN OUTCOMES AND RESULTS

There was significant change in the BMDs of lumbar vertebrae 1 week post-operatively and of both distal femurs 3 weeks post-operatively (p < 0.05). A significant change in the maximum load of femoral neck was also observed 3 weeks post-operatively between the brain injury and the sham-operation groups (p = 0.044).

CONCLUSIONS

This finding suggests that brain injury could induce osteoporosis by immobilization.

Increased cortical remodeling after osteotomy causes posttraumatic osteopenia

Following a fracture, substantial bone mineral loss can occur at the affected limb. The aim of this study was to analyze the changes in cortical bone around the site of a fracture. We analyzed bone mineral density by quantitative computed tomography and quantified changes in cortical remodeling by histomorphometry adjacent to an experimental osteotomy in sheep metatarsals. In the cortical bone around the osteotomy, we found a statistically significant 16% reduction in app.BMD within 9 weeks following surgery. This reduction was explained (R=-0.71, P<0.01) by a more than 6 fold increase in bone remodeling activity within cortical bone at the affected limb. The remodeling activity significantly increased between surgery and week 6, but remained unchanged between week 6 and week 9. We conclude from these findings that posttraumatic bone mineral loss adjacent to a fracture is related to an elevated number of active osteons, indicating a significant increase in bone remodeling activity. Load shielding by the osteosynthesis material and local recruitment of bone mineral are likely causes for this increased remodeling. This post-traumatic bone loss is likely to contribute significantly to frequently observed healing complications like refracture, failure of implant fixation, implant loosening, or cut out.

Bone mineral density of the tarsals and metatarsals with reloading

BACKGROUND AND PURPOSE

Bone mineral density (BMD) decreases rapidly with prolonged non-weight bearing. Maximizing the BMD response to reloading activities after NWB is critical to minimizing fracture risk.

METHODS

for measuring individual tarsal and metatarsal BMD have not been available. This case report describes tarsal and metatarsal BMD with a reloading program, as revealed by quantitative computed tomography (QCT).

CASE DESCRIPTION

A 24-year-old woman was non-weight bearing for 6 weeks after right talocrural arthroscopy. Tarsal and metatarsal BMD were measured with QCT 9 weeks (before reloading) and 32 weeks (after reloading) after surgery. A 26-week progressive reloading program was completed. Change scores were calculated for BMD before reloading and BMD after reloading for the total foot (average of all tarsals and metatarsals), tarsals, metatarsals, bones of the medial column (calcaneus, navicular, cuneiforms 1 and 2, and metatarsal 1), and bones of the lateral column (calcaneus, cuboid, cuneiform 3, and metatarsals 2-5). The percent differences in BMD between the involved side and the uninvolved side were calculated.

OUTCOMES

Before reloading, BMD of the involved total foot was 9% lower than that on the uninvolved side. After reloading, BMD increased 22% and 21% for the total foot, 16% and 14% for the tarsals, 29% and 30% for the metatarsals, 14% and 15% for the medial column bones, and 28% and 26% for the lateral column bones on the involved and uninvolved sides, respectively. After reloading, BMD of the involved total foot remained 8% lower than that on the uninvolved side.

DISCUSSION

The increase in BMD with reloading was not uniform across all pedal bones; the metatarsals showed a greater increase than the tarsals, and the lateral column bones showed a greater increase than the medial column bones.

Impaired geometric properties of tibia in older women with hip fracture history

This study evaluated side-to-side differences in tibial mineral mass and geometry in women with previous hip fracture sustained on average 3.5 years earlier. Both tibial mineral mass and geometry were found to be reduced in the fractured leg.

INTRODUCTION

The purpose of this study was to evaluate side-to-side differences in tibial mineral mass and geometry after hip fracture and to assess the determinants of such differences.

METHODS

Thirty-eight 60- to 85-year-old women with a previous hip fracture and 22 same-aged control women without fractures participated in the study. Bone characteristics of the distal tibia and tibial shaft of both legs were assessed using pQCT in order to compare the side-to-side differences of tibias between the two groups.

RESULTS

The subjects with fracture history had significantly (p < OR = 0.05, analysis of covariance) larger side-to-side differences than the controls in tibial shaft BMC (-4.9% vs. -0.5%), cortical area (-5.2% vs. 0.1%) and polar moment of inertia (I(polar)) (-5.6% vs. -0.8%) and in distal tibia BMC (-5.1% vs. -1.4%) and I(polar) (-7.5% vs. -2.4%). In the fracture patients, the side-to-side differences in muscle characteristics explained 23 to 44% of the variances in the side-to-side differences in bone mass and geometry.

CONCLUSIONS

Hip fracture results in reduced bone mass and impaired bone geometry in the tibia of the affected limb in older women. Muscle-induced loading may have a considerable role in the recovery of bone mineral mass and geometry after hip fracture.

A Single Infusion of Zoledronate Prevents Bone Loss After Stroke

BACKGROUND AND PURPOSE

Stroke is a major risk factor for hip fracture. Patients with intermediate rather than severe or mild stroke deficits at the time of hospital discharge have the most fractures. This proof-of-concept study evaluated the efficacy of a single infusion of zoledronate, an intravenous bisphosphonate, in preserving hip bone density after stroke.

METHODS

In a 1-year randomized, double-blind, placebo-controlled, clinical trial, 27 newly hemiplegic patients (6 females, 21 males) with acute stroke were assigned to receive 4 mg of the intravenous zoledronate (n=14) or placebo (n=13) within 35 days. Strict inclusion criteria were followed-up to ensure recruited patients were likely to have residual functional impairment. Both groups received calcium and vitamin D supplementation. The primary outcome measure was the change in bone mineral density (BMD; Lunar Prodigy) at the hemiplegic hip during the year of investigation.

RESULTS

The treatment was generally well tolerated. Mean total hip BMD was unchanged in the hemiplegic hip of the zoledronate group (mean 0.0% change), whereas in the placebo group the total hip BMD changed by -5.5%, with the greatest bone loss observed in the trochanteric subregion (mean, -8.1%). On the unaffected side the mean change in total hip BMD was +1.0% with zoledronate versus a mean change of -2.7% without. Repeated measures ANOVA confirmed the significance of the differences between groups at both hips (hemiplegic, P<0.001; unaffected, P=0.002).

CONCLUSIONS

Stroke patients were protected from the deleterious effects of hemiplegia on hip bone density for at least 1 year after a single infusion of zoledronate.

Additional weight bearing during exercise and estrogen in the rat: the effect on bone mass, turnover, and structure

Mechanical loading and estrogen play important roles in bone homeostasis. The aim of this study was to evaluate the effects of mechanical loading on trabecular bone in the proximal femur of ovariectomized rats. We hypothesized that mechanical loading suppresses bone resorption and increases bone formation, which differs from the suppressive effects of estrogen on both resorption and formation. Furthermore, we expected to find changes in trabecular architecture elicited by the effects of mechanical loading and estrogen deficiency. Sixty female Wistar rats, 12 weeks old, were assigned to either the sedentary groups sham surgery (SED), ovariectomy (SED+OVX), and ovariectomy with estrogen replacement (SED+OVX+E2) or to the exercise groups EX, EX+OVX, EX+OVX+E2. Following ovariectomy, 5 microg 17beta-estradiol was given once weekly to the estrogen replacement groups. Exercise consisted of running with a backpack (load +/-20% of body weight) for 15 minutes/day, 5 days/week, for 19 weeks. Dual-energy X-ray absorptiometry (DXA) scans were performed before (T0), during (T6), and after (T19) the exercise period to obtain bone mineral content (BMC) and bone mineral density (BMD) data. After the exercise program, all rats were killed and right and left femora were dissected and prepared for micro-CT scanning and histomorphometric analysis of the proximal femoral metaphysis. After 19 weeks, increases in BMC (P = 0.010) and BMD (P = 0.031) were significant. At T19, mechanical loading had a significant effect on BMC (P = 0.025) and BMD (P = 0.010), and an interaction between mechanical loading and estrogen (P = 0.023) was observed. Bone volume and trabecular number decreased significantly after ovariectomy, while trabecular separation, mineralizing surface, bone formation rate, osteoclast surface, degree of anisotropy, and structure model index increased significantly after ovariectomy (P < 0.05). Trabecular bone turnover and structural parameters in the proximal femur were not affected by exercise. Estrogen deficiency resulted in a less dense and more oriented trabecular bone structure with increased marrow cavity and a decreased number of trabeculae. In conclusion, mechanical loading has beneficial effects on BMC and BMD of the ovariectomized rat. This indicates that the load in the backpack was high enough to elicit an osteogenic response sufficient to compensate for the ovariectomy-induced bone loss. The results confirm that estrogen suppresses both bone resorption and bone formation in the proximal metaphysis in the femoral head of our rat-with-backpack model. The effects of mechanical loading on the trabecular bone of the femoral head were not significant. This study suggests that the effect of mechanical loading in the rat-with-backpack model mainly occurs at cortical bone sites.

Interlimb differences in lower extremity bone mineral density following anterior cruciate ligament reconstruction

STUDY DESIGN

Prospective descriptive study.

OBJECTIVE

To determine the extent of bone mineral density (BMD) interlimb differences at several hip locations in the involved versus noninvolved lower extremity following anterior cruciate ligament (ACL) surgery.

BACKGROUND

Disuse following ACL reconstruction can be extensive. This disuse not only affects the soft tissue, but may also affect the skeletal structure. The extent of this disuse specific to the proximal femur has not been previously determined.

METHODS AND MEASURES

BMD was assessed in 15 subjects, 17 to 51 years old, who were between 6 and 32 months post-ACL reconstruction surgery. Bone mineral content (BMC) and BMD of the femoral neck, trochanteric region, intertrochanteric region, and entire hip were measured as a primary emphasis of this study. BMD and BMC of the entire lower extremities were also measured bilaterally.

RESULTS

BMD was significantly less in the involved lower extremity compared to noninvolved lower extremity at several hip sites: 6.6% less (P<.001) for the trochanteric region, 4.0% less (P<.001) for the entire hip, and 3.4% less (P = .004) for the intertrochanteric region. No significant differences were noted comparing the entire lower extremities for either BMD (0.9%, P = .48) or BMC (3.7%, P= .09).

CONCLUSION

BMD differences at the hip are significant in patient's postoperative ACL reconstruction, especially in the trochanteric region.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

Changes in bone mass and bone turnover following tibial shaft fracture

INTRODUCTION

Bone loss occurs in the regional bone following tibial shaft fracture. An earlier cross-sectional study showed that measurements made at the metaphyseal region of the tibia using peripheral quantitative computed tomography (pQCT) and the ultradistal region of the tibia using dual-energy X-ray absorptiometry (DXA) were the most responsive at monitoring this bone loss. Biochemical markers of bone turnover enable us to assess the activity of bone formation and resorption during fracture healing. The aim of this longitudinal study was to determine the pattern and distribution of bone loss and bone turnover following a tibial shaft fracture treated with either plaster cast or intramedullary nail.

METHODS

Eighteen subjects underwent bone mass measurements using DXA at the tibia and hip and quantitative ultrasound (QUS) at the tibia and calcaneus of both limbs at 2 weeks, 8 weeks, 12 weeks and 24 weeks following fracture, with hip and tibia DXA measurements also performed at 52 weeks. Nine of the patients treated with plaster cast had pQCT measurements at the tibia at 24 weeks. We measured three bone formation markers, bone alkaline phosphatase (bone ALP), osteocalcin (OC) and procollagen type 1 N-terminal peptide (PINP), a marker of bone resorption, serum C-telopeptides of type 1 collagen (beta-CTX) and a marker of collagen III turnover, procollagen type III N-terminal peptide (PIIINP) at 1 day, 3 days and 7 days and at 2, 4, 8, 12, 16 and 24 weeks following fracture. The greatest bone losses were observed at the ultradistal region of the tibia using DXA (28%, p <0.001) and the metaphyseal region of the tibia using pQCT (26-31%, p <0.001) at 24 weeks. In the hip, the greatest loss was in the trochanter region at 24 weeks (10%, p <0.001). The greatest loss at the calcaneus measured using QUS was for broadband ultrasound attenuation (BUA) measured using CUBA Clinical at 24 weeks (13%, p =0.01).

RESULTS

At 1 year, there was a small recovery in bone loss (ultradistal tibia DXA, 20%, p <0.01; trochanter DXA 9%, p <0.001). Bone turnover increased following fracture (PINP +72+/-21%, p <0.0001, bone ALP +199+/-22%, p =0.004, beta-CTX +105+/-23%, p <0.0001, all at 24 weeks). There was a smaller +33+/-10% increase in osteocalcin at 24 weeks. PIIINP concentration peaked at week 8 (+57+/-9%, p <0.0001). The bone resorption marker beta-CTX showed an earlier rise (week 2, 139+/-33%) than the bone formation markers.

CONCLUSIONS

We conclude that: (1) bone loss following tibial shaft fracture occurs both proximal and distal to the fracture; (2) the decreased BMD is largest for trabecular bone in the tibia with similar measurements using DXA and pQCT; (3) there is limited recovery of bone lost at the hip and tibia at 1 year; (4) tibial speed of sound (SOS) demonstrated a greater decrease than calcaneal SOS when comparing z -scores; (5) BUA is the QUS variable that shows the biggest decrease of bone mass at the calcaneus; (6) increase in bone turnover occurs following fracture with an earlier increase in bone resorption markers and a later rise in bone formation markers.

Effect of hydroxyapatite-coated tibial components on changes in bone mineral density of the proximal tibia after uncemented total knee arthroplasty: a prospective randomized study using dual-energy x-ray absorptiometry

Sixteen patients scheduled for an uncemented total knee arthroplasty (TKA) were randomized to receive a tibial component either with (n = 8) or without (n = 8) hydroxyapatite (HA) coating. In 4 regions of interest, prospective measurements of bone mineral density (BMD) using dual-energy x-ray absorptiometry were performed in the proximal tibia. Two years after the operation, the only significant change in BMD was in the lateral tibial condyle, where BMD had increased by 6.1% (95% confidence interval: 2.3%-9.9%) in patients with tibial components without HA. The intragroup changes (0-24 months) in the uncoated group and HA-coated group were significantly different (P = .003) in these regions of interest. There was no significant effect of HA coating on bone remodeling pattern of the proximal tibia.

Loss of bone mineral of the hip and proximal tibia following rupture of the Achilles tendon

In a prospective uncontrolled study 12 patients suffering from a rupture of the Achilles tendon treated operatively with surgical repair and post-operative immobilization in a short plaster cast for 6 weeks had bilateral measurements of bone mineral content (BMC) of the proximal tibia and bone mineral density (BMD) of the femoral neck and greater trochanter. The measurements were performed by dual energy X-ray absorptiometry (DEXA) and scans were performed post-operatively within 7 days after the operation and with follow up after 6 weeks, 3, 6, and 12 months. In the operated legs, BMC of the proximal tibia showed a progressive decrease reaching a total bone loss of 6.4% (95%-CL: -10.6%; -2.3%) 1 year after the injury. Bone mineral density at the hip of the operated legs also decreased significantly and 1 year after the injury BMD was 2.5% (95%-CL: -5.5%; 0.5%) and 6.8% (95%-CL: -9.8%; -3.7%) below the initial value in, respectively, the femoral neck and greater trochanter. Patients with a previous Achilles tendon rupture must be considered to be some years ahead in their natural osteoporotic process of the bones of the affected legs, and an increased risk of osteoporotic fractures must be considered not to be only theoretical.

Semi-rigid vs rigid glass fibre casting: a biomechanical assessment

OBJECTIVES

To determine if semi-rigid synthetic casts provide any measurable advantages compared to rigid synthetic casts.

BACKGROUND

Glass fibre bandages are now commonly applied immediately post-injury to provide rigid immobilisation of the limb, for both weight bearing and non-weight bearing casts. However, composite casts that have inherent flexibility are also available and it is claimed they provide some functionality.

METHODS

Five members of the orthopaedic department each applied a rigid and a semi-rigid below elbow (Colles) and a below knee walking cast to a single volunteer subject. Joint immobilisation and functional movement was assessed using electrogoniometry and limb support using pressure transducers.

RESULTS

Semi-rigid Colles casts provided slightly greater immobilisation at the wrist while allowing full finger function and greater support to the forearm during hand movements. Similarly, semi-rigid below knee walking casts produced greater immobilisation at the ankle while allowing more forefoot movement and were less of an impediment to walking.

CONCLUSIONS

Semi-rigid casting techniques have measurable advantages compared to rigid synthetic casts and represent a further development in the conservative management of fractures and soft tissue injuries.

RELEVANCE

Semi-rigid casting is a relatively new technique that can reduce some of the problems of rigid cast immobilisation and could potentially shorten the rehabilitation phase following injury. Information about the performance of these casts to assess their value in specific applications is very limited.

Alendronate in the prevention of bone loss after a fracture of the lower leg

Fracture of a leg and the consequent absence from weight-bearing lead to local bone loss. A 1-year, single-center, prospective, randomized, double-blind study was conducted, to determine whether bone loss would occur in the proximal femur and the calcaneus after a fracture of the lower leg and whether this loss could be prevented by the antiresorptive drug bisphosphonate alendronate. Twenty-three men and 18 women with a recent unstable fracture of the lower leg were randomized to receive either 10 mg of alendronate daily or placebo. Bone mineral density (BMD) of both hips and the lumbar spine was measured at baseline and 6 weeks and 3, 6, and 12 months after start of the treatment. Quantitative ultrasound (QUS) measurements of the calcaneus were performed at baseline on the noninjured side and at 6 weeks and 3, 6, and 12 months after start of treatment on both sides. After 1 year, in the placebo group, there was a significant decrease from baseline in BMD of the hip on the side of the fracture. In the alendronate group, there was no significant change from baseline. The differences in BMD between the two treatment groups on the side of the fracture were significant in all sites of the hip: 4.4% (p = 0.016) in the trochanter, 4.6% (p = 0.016) in the femoral neck, and 3.9% (p = 0.009) in the total hip. In the hip on the contralateral side, there were no significant changes from baseline in either treatment group and there was no difference between the two treatment groups. BMD in the lumbar spine increased in the alendronate group, and after 1 year there was a significant difference between the active treatment and placebo group of 3.4% (p = 0.04). One year after fracture, ultrasound parameters of the calcaneus in the placebo group were significantly lower on the fractured side compared with the contralateral side (p < 0.01). In the alendronate group, no significant difference between the two sides was observed. In conclusion, BMD of the proximal femur was still decreased 1 year after a fracture of the lower leg. Alendronate prevented this bone loss.

Limited bone loss in the hip and heel after reamed intramedullary fixation and early weight-bearing of tibial fractures

OBJECTIVE

To determine changes in bone mineral density at the hip and calcaneus in the injured and uninjured sides after surgery for tibial fractures.

DESIGN

Prospective, longitudinal study.

SETTING

University hospital.

PATIENTS AND METHODS

Twenty-six patients with a tibial fracture were treated with a reamed and statically locked intramedullary nail with early weight-bearing. Dual-energy x-ray absorptiometry at the proximal femur and quantitative ultrasonography at the calcaneus were performed bilaterally after surgery and after three, six, and twelve months.

RESULTS

At three months, the bone mineral density in the trochanteric region in the injured limb had decreased almost 4 percent (p < 0.007), a reduction still present at twelve months, whereas in the femoral neck, the reduction was approximately 2.5 percent at twelve months (p < 0.03). The stiffness index and speed of sound at the calcaneus on the injured side decreased (p < 0.03 and p < 0.008, respectively) during the first three months, whereas at twelve months, there was no significant difference when compared with those measured directly after surgery. There were no significant changes at any time in the proximal femur or calcaneus of the uninjured limb.

CONCLUSION

Treatment with a reamed statically locked intramedullary nail and early weight-bearing resulted in limited bone loss in the proximal femur and calcaneus of the injured limb. After twelve months, the bone properties at the heel were restored, whereas there was still a small reduction at the hip. Compared with previous studies of patients with similar fractures treated with casts and restricted weight-bearing, the loss in bone mineral density was less and not as longstanding.

Biomechanical and histological aspects of fracture healing, stimulated with osteogenic protein-1

Fracture healing could be stimulated with osteoinductive bone morphogenetic proteins (bmp's), such as osteogenic protein-1 (OP-1), but little is known about its effectiveness in stimulation of fracture healing. In this study, biomechanical and histological aspects of fracture healing after an injection of OP-1 in the fracture gap were investigated. In 40 goats, a closed fracture was created in the left tibia. The fractures were stabilized with an external fixator and the animals were assigned to four different groups: no injection, injection of 1 mg OP-1, injection of 1 mg OP-1 with collagenous carrier material, and injection of carrier material alone. Twenty-one animals were sacrificed after 2 weeks and 19 after 4 weeks. Biomechanical testing was perfomed on both explanted tibiae. Four longitudinal samples of the fracture were sawn, processed for histology, and examined by two observers. Biomechanical evaluation showed a higher stiffness and strength at 2 weeks after injection of OP-1. Histological evaluation showed normal fracture healing patterns in all animals without adverse effects of the given injections. These data show that fracture healing can be accelerated with a single injection of OP-1, eventually resulting in normally healed bone.

Evaluation of strength of healing fractures with dual energy Xray absorptiometry

Dual energy xray absorptiometry was investigated as a method for evaluation of the strength of closed tibial fractures. In 40 goats, a closed midshaft fracture was created in the left tibia. The fractures were stabilized with an external fixator. After 2 weeks (n = 21) and after 4 weeks (n = 19), both tibias were explanted and, using dual energy xray absorptiometry, bone mineral density and bone mineral content were measured in a 1 cm region. With nondestructive bending tests, area ratio and stiffness index were determined and torsional strength and torsional stiffness were determined with a torsional test to failure. Linear regression analysis was used to calculate the squared correlation coefficients for the relations between dual energy xray absorptiometry and the outcome of the mechanical tests. The squared correlation coefficients for the relation between bone mineral density and torsional strength, torsional stiffness, and area ratio and stiffness index were 0.72, 0.76, 0.64, and 0.72, respectively. The squared correlation coefficients for the relation between bone mineral content and these mechanical parameters were 0.72, 0.77, 0.63, and 0.77, respectively. The results using dual energy xray absorptiometry indicate the strength of healing closed fractures. Additional research is required to investigate specific aspects of this technique.

Treatment with risedronate or alendronate prevents hind-limb immobilization-induced loss of bone density and strength in adult female rats

Immobilization leads to rapid loss of bone mass and mechanical competence, and long-term immobilization or repeated periods of short-term immobilization can have serious skeletal consequences and may lead to increased fracture liability. The aim of the present preclinical study was, therefore, to assess whether two antiresorptive agents, risedronate (Ris) or alendronate (Aln), would be capable of preventing immobilization-induced loss of bone mass and strength in rats. The study was designed as a dose-response study, and the site-specific effects of immobilization and of treatment are described. Four-month-old virgin female Sprague-Dawley rats were divided into eight groups with 12 animals in each group: (1) immobilized (Imm) control; (2) normal control; (3) Imm + Ris 0.1 mg/kg body weight/day (b.w./day); (4) Imm + Ris 0.2 mg/kg b.w./day; (5) Imm + Ris 1.0 mg/kg b.w./day; (6) Imm + Aln 0.2 mg/kg b.w./day; (7) Imm + Aln 1.0 mg/kg b.w./day; and (8) Imm + Aln 2.0 mg/kg b.w. /day. In groups 1 and 3-8, the right hind leg was immobilized with an elastic bandage. The study period was 28 days. The effects of unilateral hind-limb immobilization and of treatment were determined by dual-energy X-ray absorptiometry (DEXA) measurements on tibiae and by biomechanical testing of femora at three different sites: diaphysis; femoral neck; and distal metaphysis. Bilateral measurements were performed (on the immobilized and nonimmobilized legs). Immobilization induced a significant loss of bone mineral density (BMD) at the proximal tibial metaphysis, but no change at the mid-diaphysis. Furthermore, immobilization induced a loss of bone strength at the two femoral metaphyses, but no change was seen in three-point bending of the diaphysis. Both risedronate and alendronate treatment showed a dose-dependent protection against the immobilization-induced loss of bone density and strength at the metaphyses. We conclude that, in rats, short-term hind-limb immobilization affects only the metaphyses and that no changes are seen in the diaphysis. Both risedronate and alendronate can prevent immobilization-induced bone loss at the metaphyses. The present study confirms the importance of examining several skeletal sites when testing the efficacy of therapeutic agents.

Collagen structure regulates fibril mineralization in osteogenesis as revealed by cross-link patterns in calcifying callus

Although >80% of the mineral in mammalian bone is present in the collagen fibrils, limited information is available about factors that determine a proper deposition of mineral. This study investigates whether a specific collagen matrix is required for fibril mineralization. Calcifying callus from dog tibias was obtained at various times (3-21 weeks) after fracturing. At 3 weeks, hydroxylysine (Hyl) levels were almost twice as high as in control bone, gradually reaching normal levels at 21 weeks. The decrease in Hyl levels can only be the result of the formation of a new collagen network at the expense of the old one. The sum of the cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) in callus matched that of bone at all stages of maturation. However, the ratio HP/LP was 2.5-4.5 times higher in callus at 3-7 weeks than in normal bone and was normalized at 21 weeks. Some 40% of the collagen was nonmineralized at the early stages of healing, reaching control bone values (approximately 10%) at 21 weeks. In contrast, only a small increase in callus mineral content from 20.0 to 22.6 (% of dry tissue weight) from week 3 to 21 was seen, indicating that initially a large proportion of the mineral was deposited between, and not within, the fibrils. A strong relationship (r = 0.80) was found between the ratio HP/LP and fibril mineralization; the lower the HP/LP ratio, the more mineralized the fibrils were. Because the HP/LP ratio is believed to be the result of a specific packing of intrafibrillar collagen molecules, this study implies that mineralization of fibrils is facilitated by a specific orientation of collagen molecules in the fibrils.

The effect of alendronate on bone mass after distal forearm fracture

Fracture and immobilization of an extremity lead to bone loss at the fracture and at adjacent sites. We conducted a 1-year, single-center, prospective, randomized, double-blind study to determine whether bone loss would occur in the distal radius after a Colles' fracture and whether this loss could be prevented using an antiresorptive drug (alendronate). Thirty-seven women with a recent fracture of the distal forearm and low bone mineral density (BMD) of the lumbar spine were randomized to receive either 10 mg alendronate daily or placebo. BMD of both forearms was measured at baseline and after 3, 6, and 12 months. The results of four women who developed reflex sympathetic dystrophy were not included in the analysis. In the placebo group, there was a significant reduction at 3 months and 6 months in BMD of total radius (p < 0.01), one-third distal radius (p < 0.01), middistal radius (p < 0.05), and ultradistal radius (p < 0.01) on the fractured side. The loss in BMD at one-third distal radius remained significant at month 12 (p < or = 0.001). In the alendronate group BMD of total distal radius, one-third distal radius, and middistal radius at the fractured side remained unchanged. BMD of ultradistal radius increased significantly at months 3, 6, and 12, compared with baseline (p < 0.05). The difference between the two treatment groups was significant at 3 months and 6 months and borderline significant (p = 0.054) after 1 year in total distal radius. In ultradistal radius the differences were significant at all time points. We conclude that BMD of the distal radius of a recently fractured forearm decreases significantly in the 6 months after fracture and the resulting deficit remains evident at least 1 year after fracture. This bone loss can be prevented by alendronate.

Bone mineral density 6 years after a hip fracture: a prospective, longitudinal study

The purpose of this prospective study was to extend the results of previous studies to determine if an accelerated rate of loss of bone mineral density (BMD) continues for 6 years after a hip fracture. Eighty-five elderly patients who had sustained a hip fracture had determinations of BMD made at the time of fracture; 55 of these patients were available for reassessment of BMD 1 year later, and 21 were available for reassessment of BMD 6 to 7 years later. The change in BMD from injury to 1 year and from 1 to 6 years was determined and correlated with pre- and postinjury variables, such as ambulatory ability, dietary intake of calcium, serum vitamin D levels, and mental status. There was a marked decrease in BMD in the in the first year after fracture, with the mean change in BMD being -4.3% at the femoral neck and -1.8% at the lumbar spine. Between 1 and 6 years after fracture, however, there was a dramatic increase in the BMD at both the femoral neck and lumbar spine measurement sites. Relative to 1 year after fracture, the mean increases were 7.7% at the femoral neck and 4.5% at the lumbar spine. In many cases, the loss of bone mineral that occurred in the first year after fracture was completely recouped in the subsequent 5 years. Five of the 21 patients (24%) sustained a contralateral hip fracture in the 6 years after the index fracture. Lumbar spine BMD was lower at baseline (p = 0.112), 1 year after fracture (p = 0.007), and 6 years after fracture (p = 0.003) in patients who sustained a second hip fracture than in those who did not. There was a general decrease in the functional activity level of patients in the 6 years after a hip fracture, but there were no statistically significant relationships between changes in BMD and the functional mobility of patients. The mean calcium intake in patients improved remarkably in the 6 years after fracture, but there was no correlation between daily calcium intake and changes in BMD. During the first year after a hip fracture, there is a rapid loss of bone mineral from the lumbar spine and contralateral femoral neck. Between 1 and 6 years after fracture, however, BMD is likely to increase, perhaps to levels greater than those at baseline. Although this investigation is small, the findings of this study point to the importance of further larger studies to further clarify the natural history of BMD after a hip fracture and the potential impact of pharmacological intervention on that natural history.

Long-term consequences of fracture of the lower leg: cross-sectional study and long-term longitudinal follow-up of bone mineral density in the hip after fracture of lower leg

The purpose of this study was to investigate whether bone loss in the hip, occurring after a fracture of the lower leg, persists many years after the fracture. In a long-term follow-up we measured bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine in a group of 11 patients, 5 years after a fracture of the lower leg. These patients were part of an earlier study, evaluating bone loss in the hip, up to 1 year after fracture of the lower leg. In this follow-up study, 5 years after fracture, loss from baseline BMD in the trochanteric region of the ipsilateral hip was 4.7% (p=0.04), whereas after a year in this group there was a decrease of 12.5% from baseline. On the contralateral side, hardly any change occurred. In the ipsilateral femoral neck, 5 years after fracture, BMD decreased by 2.9% (p=0.10), after 1 year loss from baseline was 5.1%. In a cross-sectional study we examined the differences in BMD of both hips, measured by DXA, in a group of 19 elderly patients reporting a fracture of the lower leg, with a mean time of 9.3 years after fracture. In this study, we found a 4.7% lower BMD in the trochanteric region of the hip on the fractured side compared with the nonfractured side (p=0.006), and a 2.9% lower BMD in the femoral neck (p=0.25). We conclude that, after fracture of the lower leg, BMD in the ipsilateral hip decreases significantly, with maximal bone loss after 1 year. After 5 years recovery has occurred, but not to baseline. Thereafter, significant excess bone loss is still observed in the trochanteric region. This persisting lower BMD may lead to an increased risk of another fracture in later years.

Fall direction, bone mineral density, and function: risk factors for hip fracture in frail nursing home elderly

PURPOSE

To determine the importance of fall characteristics, body habitus, function, and hip bone mineral density as independent risk factors for hip fracture in frail nursing home residents.

SUBJECTS AND METHODS

In this prospective, case-control study of a single, long-term care facility, we enrolled 132 ambulatory residents (95 women and 37 men) aged 65 and older, including 32 cases (fallers with hip fracture) and 100 controls (fallers with no hip fracture). Principal risk factors included fall characteristics, body habitus, measures of functional assessment, and hip bone mineral density by dual-energy X-ray absorptiometry.

RESULTS

In multivariate analysis, including only those with knowledge of the fall direction (n=100), those who fell and suffered a hip fracture were more likely to have fallen sideways (odds ratio 5.7, 95% confidence interval [CI] 1.7 to 18, P= 0.004) and have a low hip bone mineral density (odds ratio 1.9, 95% CI 0.97 to 3.7, P=0.06) than those who fell and did not fracture. When all participants were included (n=132) and subjects who did not know fall direction were coded as not having fallen to the side, a fall to the side (odds ratio 3.9, 95% CI 1.3 to 11, P=0.01), low hip bone density (odds ratio 1.8, 95% CI 1.03 to 3, P=0.04), and impaired mobility (odds ratios 6.4, 95% CI 1.9 to 21, P=0.002) were independently associated with hip fracture. Sixty-seven percent of subjects (87% with and 62% without hip fracture) had a total hip bone mineral density greater than 2.5 SD below adult peak bone mass and were therefore classified as having osteoporosis using World Health Organization criteria.

CONCLUSIONS

Among frail elderly nursing home fallers, the preponderance of whom are osteoporotic, a fall to the side, a low hip bone density, and impairment in mobility are all important and independent risk factors for hip fracture. These data suggest that, among the frailest elderly, measures to reduce the severity of a sideways fall and improve mobility touch on new domains of risk, independent of bone mineral density, that need to be targeted for hip fracture prevention in this high-risk group.

Loss of bone mineral of the hip assessed by DEXA following tibial shaft fractures

We measured prospectively early changes (0-6 months) in bone mineral of the hip, the lumbar spine, and the tibia following tibial shaft fractures (n = 12), and in a cross-sectional study we evaluated the maximal amount of bone loss possible at the hip and tibia following long-term (average 3 years) impaired limb function as a consequence of complicated tibial shaft fractures [delayed union or nonunion (n = 7), chronic osteomyelitis (n = 5), decreased limb length (n = 1), or bone defect (n = 1)]. Bone mineral measurements were performed by dual energy X-ray absorptiometry. Following tibial shaft fractures, a significant decrease in bone mineral density (BMD) was seen at the hip reaching 7% [confidence limits (CL): -10.2%; -3.5%] and 14% (CL: -19.6; -7.8%) after 6 months for the femoral neck and greater trochanter, respectively. In the proximal tibia, bone mineral content (BMC) decreased and was 19% (CL: -27.4%; -9.9%) below the initial value after 6 months. BMD of the lumbar spine remained unchanged. In the cross-sectional study, BMC in the tibia of the injured legs was 43% (CL: -53.2%; -31.9%) below the value in the healthy contralateral legs, and BMD in the femoral neck and greater trochanter, respectively, was 22% (CL: -27.4%; -17.6%) and 24% (CL: -36.3%; -12.1%) below the values in the healthy contralateral legs. With respect to the expected age-related decay of bone mineral after peak bone mass, the loss of bone mineral of the hip and tibia associated with tibial shaft fractures may be considered of clinical importance with increased risk of sustaining a fragility fracture of the lower extremity later in life; and the complicated fractures may even represent a present risk of fracture.

Dual-energy X-ray absorptiometry as a measure of healing in fractures treated by intramedullary nailing

The conventional qualitative techniques of manual manipulation and plain radiography do not give a quantifiable measurement of healing. With internal fixation, manual manipulation is not usually possible, and conventional radiographs may not give much useful information, particularly if only a small amount of callus is formed. Dual-energy x-ray absorptiometry (DXA) provides an accurate method of quantifying the changes in bone mineral density (BMD) which occur during fracture healing. Preliminary work showed that the presence of a highly attenuating metal implant in the scan area did not affect the reliability of BMD data obtained from scans. On this basis, we have assessed the use of DXA in the clinical situation to monitor fractures treated by intramedullary nailing. Five fractures of the mid-shaft of the tibia stabilized by interlocked intramedullary nails have been monitored by DXA at monthly intervals through healing. DXA improves on radiography in giving a quantitative measure of fracture site mineralization. However, it is concluded that, because of the relatively small changes in callus BMD encountered with the rigid fixation provided by interlocked intramedullary nailing, DXA offers no significant diagnostic advantages over plain radiography.

Bone mineral density in women with depression

BACKGROUND

Depression is associated with alterations in behavior and neuroendocrine systems that are risk factors for decreased bone mineral density. This study was undertaken to determine whether women with past or current major depression have demonstrable decreases in bone density.

METHODS

We measured bone mineral density at the hip, spine, and radius in 24 women with past or current major depression and 24 normal women matched for age, body-mass index, menopausal status, and race, using dual-energy x-ray absorptiometry. We also evaluated cortisol and growth hormone secretion, bone metabolism, and vitamin D-receptor alleles.

RESULTS

As compared with the normal women, the mean (+/-SD) bone density in the women with past or current depression was 6.5 percent lower at the spine (1.00+/-0.15 vs. 1.07+/-0.09 g per square centimeter, P=0.02), 13.6 percent lower at the femoral neck (0.76+/-0.11 vs. 0.88+/-0.11 g per square centimeter, P<0.001), 13.6 percent lower at Ward's triangle (0.70+/-0.14 vs. 0.81+/-0.13 g per square centimeter, P<0.001), and 10.8 percent lower at the trochanter (0.66+/-0.11 vs. 0.74+/-0.08 g per square centimeter, P<0.001). In addition, women with past or current depression had higher urinary cortisol excretion (71+/-29 vs. 51+/-19 micrograms per day [196+/-80 vs. 141+/-52 nmol per day], P=0.006), lower serum osteocalcin concentration (P=0.04), and lower urinary excretion of deoxypyridinoline (P=0.02).

CONCLUSIONS

Past or current depression in women is associated with decreased bone mineral density.

A rotator cuff rupture produces permanent osteoporosis in the affected extremity, but not in those with whom shoulder function has returned to normal

Areal bone mineral density (BMD) and clinical status of 34 men treated surgically 9 years earlier for a rotator cuff rupture of the dominant side shoulder were determined. The BMD was measured at the lumbar spine (L2-L4) and the proximal humerus, humeral shaft, radial shaft, ulnar shaft, distal forearm, and hand of both extremities using a dual-energy X-ray absorptiometric (DXA) scanner. Thirty-four age-, height-, weight-, and profession-matched normal men (controls) were also measured. The patients' mean side-to-side BMD difference (dominant minus nondominant/nondominant x 100%) was significantly lower in the proximal humerus (patients -3.5% vs. controls +2.4%, p = 0.0002), humeral shaft (-2.6% vs. +1.6%, p = 0.0005), radial shaft (-0.4% vs. +1.9%, p = 0.0311), distal forearm (-0.2% vs. +2.4%, p = 0.0158), and hand (+2.3% vs. +4.0%, p = 0.0047). In the ulnar shaft, this difference was almost the same in the patients (-0.2%) and controls (+0.2%) (NS). Also, the lumbar spine BMD did not differ significantly between these groups (mean +/- SD = 1.098 +/- 0.148 g/cm2 in patients vs. 1.066 +/- 0.156 g/cm2 in controls). In patients, the relative BMDs of the injured extremity did not significantly associate with the size of the rupture; time delay between the injury and the surgery; type of surgery and postoperative treatment; postoperative immobilization time; follow-up time; patient's age, muscle strength or pain assessment; and subjective assessment of shoulder function. However, they strongly associated with the objective assessment of the shoulder function: the better the observed function of the shoulder, the less bone loss caused by the injury.(ABSTRACT TRUNCATED AT 250 WORDS)