Associations between ethnicity, body composition, and bone mineral density in a Southeast Asian population.

CONTEXT AND OBJECTIVE: Chinese men in Singapore have a higher incidence of hip fractures than Malay and Indian men. We investigated whether there were corresponding ethnic differences in peak bone mineral density (BMD) in young men and whether differences in body composition influenced peak BMD. DESIGN AND SETTING: This was a cross-sectional study of healthy volunteers in a tertiary medical center. PARTICIPANTS: A total of 100 Chinese, 82 Malay, and 80 Indian men aged 21 to 40 years, with body mass index between 18 and 30 kg/m(2) underwent dual-energy x-ray absorptiometry to assess BMD, lean mass (LM) and fat mass (FM), and magnetic resonance imaging to quantify abdominal subcutaneous and visceral adipose tissue. Multiple linear regression models, with adjustment for age and height (as a proxy for skeletal size), were used. RESULTS: Malay and Indian men had significantly higher BMD than Chinese men at the lumbar spine (Malay: B, 0.06 ± 0.02, P = .001; Indian: B, 0.03 ± 0.02, P = .049), femoral neck (Malay: B 0.04 ± 0.02, P = .034; Indian: B, 0.04 ± 0.02, P = .041), hip (Malay: B, 0.05 ± 0.02, P = .016; Indian: B, 0.06 ± 0.02, P = .001), and ultradistal radius (Malay: B, 0.03 ± 0.01, P < .001; Indian: B, 0.02 ± 0.01, P = .029), and this difference was retained after adjustment for LM and FM, except in Malay men at the femoral neck and in Indian men at the ultradistal radius. LM was an important independent determinant of BMD at all sites, whereas FM, subcutaneous adipose tissue, and visceral adipose tissue were not significantly associated with BMD at any site. CONCLUSIONS: Lower peak BMD in Chinese men may partly explain the higher fracture incidence in this ethnic group. Further studies are needed to elucidate the reasons for these ethnic differences in bone accumulation.

Femoral shaft fractures in the elderly--role of prior bisphosphonate therapy.

INTRODUCTION: There is a recent surge in interest on bisphosphonate related femoral fractures. Most studies have examined subtrochanteric fractures in patients on long-term bisphosphonates. This study evaluates the characteristics of low-impact femoral shaft fractures in elderly patients on long-term alendronate. MATERIALS AND METHODS: All patients above 60 years old admitted to the National University Hospital for femoral shaft fracture from January 2003 to January 2007 were retrospectively analysed. Of the 55 patients included, 7 had prior alendronate therapy and were examined in detail. RESULTS: All 7 patients on prior alendronate therapy sustained their fractures by low-impact or atraumatic mechanisms of injury. 5 of these 7 patients exhibited a characteristic fracture pattern of thickened lateral cortices at the proximal fracture fragment (p<0.05) and all 7 patients had either transverse or short oblique fractures. Notably, none of the 7 patients had bone mineral density scans prior to their fractures. One patient was started on alendronate after a vertebral compression fracture, whilst the other 6 patients were started on alendronate without any clear clinical indication. All 7 patients reported prodromal thigh pain 3 weeks to 2 years prior to the fracture. CONCLUSIONS: Low-impact femoral shaft fractures in elderly patients on long-term alendronate therapy represent a new entity of insufficiency fractures, with characteristic low-impact modes of injury and fracture patterns on radiograph. Prodromal thigh pain is a warning sign for impending fracture in this group of patients and should be evaluated closely. Teriparatide is a possible alternative to alendronate following such a fracture though more long-term clinical studies are required.

A rational approach to management of alendronate-related subtrochanteric fractures.

There have been recent reports linking alendronate and a specific pattern of subtrochanteric insufficiency fracture. We performed a retrospective review of all subtrochanteric fractures admitted to our institution between 2001 and 2007. There were 20 patients who met the inclusion criteria, 12 of whom were on long-term alendronate. Alendronate-associated fractures tend to be bilateral (Fisher's exact test, p = 0.018), have unique radiological features (p < 0.0005), be associated radiologically with a pre-existing ellipsoid thickening of the lateral femoral cortex and are likely to be preceded by prodromal pain. Biomechanical investigations did not suggest overt metabolic bone disease. Only one patient on alendronate had osteoporosis prior to the start of therapy. We used these findings to develop a management protocol to optimise fracture healing. We also advocate careful surveillance in individuals at-risk, and present our experience with screening and prophylactic fixation in selected patients.

Modified Brostrom-Evans-Gould technique for recurrent lateral ankle ligament instability.

PURPOSE: To review the outcome of the modified Brostrom-Evans-Gould technique in patients with chronic lateral ankle ligament instability. METHODS: Between August 2003 and June 2005, 20 men aged 19 to 35 (mean, 23) years with chronic lateral instability affecting 21 ankles, underwent the modified Brostrom-Evans-Gould technique by a single surgeon. The mean follow-up period was 12 (range, 6-20) months. Patients were assessed preoperatively and postoperatively using the Kaikkonen Ankle Scoring Scale. RESULTS: Preoperatively, all patients had poor scores (<50). Postoperatively, 17 (81%) of the ankles attained excellent scores (85-100) and 4 (19%) attained good scores (70-84). CONCLUSION: The modified Brostrom-Evans-Gould technique appears effective for chronic lateral ankle ligament instability, particularly in the Asian population with a higher prevalence of generalised joint hyperlaxity.

Acetabular morphometry for determining hip dysplasia in the Singaporean population.

PURPOSE: To assess and evaluate the usefulness of 7 morphological measurements of the acetabulum in establishing the prevalence of acetabular dysplasia in the Singaporean population. METHODS: Standardised plain anteroposterior radiographs of 522 hip joints of 261 asymptomatic patients (mean age, 60 years; range, 16-99 years) were evaluated. The 7 morphological measurements were centre-edge angle, acetabular angle, depth-to-width ratio, roof obliquity, extrusion index, lateral subluxation, and peak-to-edge distance. RESULTS: 19 (7.3%) patients were acetabular dysplastic (centre-edge angle of <20 degrees). The mean centre-edge angle was 31.2 degrees (range, 5-52 degrees), acetabular angle 39.46 degrees (range, 10-58 degrees), depth-to-width ratio 0.32, roof obliquity 7.86 degrees, extrusion index 0.18, lateral subluxation 9.9 mm, and the peak-to-edge distance 15.65 mm. CONCLUSION: Centre-edge angle was the most useful measurement and correlated significantly with acetabular angle, extrusion index, peak-to-edge distance, and roof obliquity. These preliminary results show a relatively higher rate (7.3%) of acetabular dysplasia in the Singaporean population, compared with other similar but larger Asian studies performed in Hong Kong (1.1%) and Korea (1.8%).

Gait adaptations in patients with longstanding hip fusion.

PURPOSE: To examine the long-term effects of hip arthrodesis in terms of gait adaptations. METHODS: Motion analysis was performed on 9 patients who underwent unilateral hip arthrodesis between 1979 and 1991. A standard clinical gait analysis 3-dimensional model for the lower limb was used to calculate the effect of the fused hip on walking, compared with the contralateral normal hip. RESULTS: Significant (p<0.05) gait adaptations noted in the fused side were, compensatory hip hiking during the swing-phase, a 24% reduction in hip adduction moment, a 37% decrease in genu-varus moment, 80% reduced hip power, and excessive pelvic tilt. CONCLUSION: It appears that the excess pelvic tilt observed was to achieve relative hip extension via increased relative lumbar lordosis, while the decreased coronal plane moments of the hip and knee observed were to reduce joint loading on the affected side.

The incidence of proximal deep vein thrombosis following total knee arthroplasty in an Asian population: a Doppler ultrasound study.

PURPOSE: To investigate the incidence of deep vein thrombosis (DVT) following total knee arthroplasty in an Asian population. METHODS: A prospective study of 149 consecutive cases of total knee arthroplasty done for osteoarthritis was conducted over a 5-year period. All patients underwent duplex ultrasonographic assessment of the lower limbs within the first postoperative week. RESULTS: The incidence of proximal DVT was found to be 4.38% in this study. Symptomology was statistically significant in predicting the presence of proximal DVT in all cases. General anaesthesia was associated with a statistically significant-higher incidence of DVT as compared with regional anaesthesia. There was a significant association between a sedentary lifestyle and the development of DVT. CONCLUSION: The incidence of proximal DVT in Asian patients after total knee arthroplasty is higher than that previously reported for this demographic group.

The Internet as a source of health information among Singaporeans: prevalence, patterns of health surfing and impact on health behaviour.

OBJECTIVE: The Internet is an increasingly popular source of healthcare information. This study describes the prevalence of health surfers in Singapore and their health-surfing patterns. It also assesses their confidence in online health information and the impact the Internet has on health-seeking behaviour. MATERIALS AND METHODS: A cross-sectional survey using a standardised questionnaire was carried out among residents aged 13 to 55 years in 1852 units in Bishan North. These units were selected by single-stage simple random cluster sampling method. RESULTS: The household response rate was 51% (n = 950) and the individual response rate was 69% (n = 1646). Responding and non-responding households were similar in terms of ethnicity and housing type. Of the responders, 62.9% surfed the Internet and 37.7% have surfed for health information. Health surfers tended to be younger (20 to 39 years) and have higher education status. Indians were also more likely than other ethnic groups to surf for health. Professional health-related sites comprised the majority (68%) of sites visited, and the most common search keywords concern chronic degenerative diseases, e.g. hypertension. The top preferred sources of health information were doctors (25.9%), the Internet (25.3%) and the traditional mass media (20.5%). Almost half (45.1%) considered online health information trustworthy if it was from a professional source or if the website displayed the source, while 10.6% trusted the information if it concurred with the doctors' advice. The vast majority (91.7%) had taken some action in response to the information. CONCLUSION: The Internet is being used as an accessible source of health information by a substantial proportion of the lay public. While this can facilitate greater partnership in healthcare, it underlines the need for doctors to be pro-active in the practice of evidence-based medicine, and for guidelines to enable patients to use this tool in a discerning manner.

The incidence of hip fracture in four Asian countries: the Asian Osteoporosis Study (AOS).

The Asian Osteoporosis Study (AOS) is the first multicenter study to document and compare the incidence of hip fracture in four Asian countries. Hosital discharge data for the year 1997 were obtained for the Hong Kong SAR, Singapore, Malaysia and Thailand (Chiang Mai). The number of patients who were 50 years of age and older and who were discharged with a diagnosis of hip fracture (ICD9 820) was enumerated. The age-specific incidence rates were deduced and were directly adjusted to the US white population in 1989. The age-adjusted rates for men and women (per 100,000) are as follows: Hong Kong, 180 and 459; Singapore, 164 and 442; Malaysia, 88 and 218; Thailand, 114 and 289; compared with US White rates of 187 in men and 535 in women, published in 1989. We conclude that there is moderate variation in the incidence of hip fracture among Asian countries. The rates were highest in urbanized countries. With rapid economic development in Asia, hip fracture will prove to be a major public health challenge.

Risk factors for hip fracture in Asian men and women: the Asian osteoporosis study.

The objectives of the Asian Osteoporosis Study (AOS) were to determine risk factors for hip fracture in men and women in four Asian countries, that is, Singapore, Malaysia, Thailand, and the Philippines. A total of 451 men and 725 women (aged 50 years and over) with hip fractures were compared with an equal number of community controls. A standardized questionnaire was administered by interview. The following relative risks (RRs) were found in women and men by multiple logistic regression: dietary calcium intake < 498 mg/day, 2.0 for women (95% CI, 1.5-2.8) and 1.5 for men (95% CI, 1.0-2.2); no load bearing activity in the immediate past, 2.0 for women (95% CI, 1.4-2.7) and 3.4 for men (95% CI, 2.3-5.1); no vigorous sport activities in young adulthood, 7.2 for women (95% CI, 4.0-13.0) and 2.4 for men (95% CI, 1.6-3.6); cigarette smoking, 1.5 for men (95% CI, 1.0-2.1); alcohol consumption 7 days a week, 2.9 for women (95% CI, 1.0-8.6) and 1.9 for men (95% CI, 1.1-3.2); fell twice or more in the last 12 months, 3.0 for women (95% CI, 1.8-4.8) and 3.4 for men (95% CI, 1.8-6.6); a history of fractures after 50 years of age, 1.8 for women (95% CI, 1.1-2.9) and 3.0 for men (95% CI, 1.6-5.6); a history of stroke, 3.8 for women (95% CI, 2.0-7.1) and 3.6 for men (95% CI, 1.8-7.1); use of sedatives, 2.5 for women (95% CI, 1.0-6.3) and 3.0 for men (95% CI, 1.0-9.7); and use of thyroid drugs, 7.1 for women (95% CI, 2.0-25.9) and 11.8 for men (95% CI, 1.3-106.0). Women who were 1.56 m or taller had an RR of 2.0 (95% CI, 1.3-3.0) for hip fracture and men who were 1.69 m or taller had an RR of 1.9 (95% CI, 1.2-3.1) for hip fracture. Based on these findings, primary preventive programs for hip fracture could be planned in Asia.

The Singapore operation for recurrent dislocation of peroneal tendons: long-term results.

Recurrent dislocation of peroneal tendons is uncommon and there are few reports of the long-term results after repair. The Singapore operation, first described in 1985, is an anatomical repair based on the Bankart-like lesion seen in the superior peroneal retinaculum. We reviewed 21 patients after a mean follow-up of 9.3 years, and found no recurrence. Eighteen had good functional results and had returned to their previous levels of vocational and sports activities. The three fair results were due to painful scars or neuromas.

Severe metallosis in an isoelastic hip prosthesis.

Severe black staining due to metallic wear debris has been reported in metal-on-metal hip prosthesis(3). This problem is not commonly seen because of the popular use of metal-on-polyethylene component and has not been previously reported with the use of isoelastic femoral prosthesis. We report a case of severe metallosis in an isoelastic prosthesis, four years after implantation.

Periprosthetic bone remodelling after cementless total hip replacement. A prospective comparison of two different implant designs.

In a prospective study of 14 patients undergoing total hip replacement we have used dual-energy X-ray absorptiometry (DEXA) to investigate remodelling of the bone around two different designs of cementless femoral prosthesis. The bone mineral density (BMD) was measured at 12-weekly intervals for a year. Eight patients (group A) had a stiff, collarless implant and six (group B) a flexible isoelastic implant. Patients in group A showed a decrease in BMD from 14 weeks after operation. By 12 months, the mean loss in BMD was 27%, both medially and laterally to the proximal part of the implant. Those in group B showed an overall increase in BMD which reached a mean of 12.6% on the lateral side of the distal portion of the implant. Our results support the current concepts of the effects of stem stiffness and flexibility on periprosthetic remodelling.

A diagnostic dilemma in an elderly patient with bone pains.

A 61-year-old patient presented with multiple bone pains. Biochemical, haematological and radiological investigations initially suggested a diagnosis of osteomalacia because of the presence of hypocalcaemia and looser zones. There were also multiple lytic bone lesions and bone scan showed multiple hot spots suggesting multiple bone secondaries. The key investigation in this case was examination of the bone marrow.

Ipsilateral knee ligament injuries and open tibial diaphyseal fractures: incidence and nature of knee ligament injuries sustained.

Fifty patients with isolated open tibial shaft fractures were reviewed to determine the incidence and type of knee ligament injuries sustained. Eighteen patients (36 per cent) had at least one ligament injury in the ipsilateral knee; eight had multiple ligament injuries. Only four patients (22 per cent) were diagnosed as having a ligament injury at the time of initial management and the remaining 14 patients were diagnosed at the time of review for this study. There is a high incidence of ipsilateral knee ligament injuries in open tibial shaft fractures; the knee should be thoroughly examined at the time of initial fracture management.

Pattern of fall and bone mineral density measurement in hip fractures.

The objectives of this study were to determine the pattern of fall and the bone mineral density distribution in hip fracture patients. The study was carried out on 260 patients (204 females and 56 males) with hip fractures over a period of three years (i.e. 1991 to 1993). The patients were all above 50 years old and the average age was 77.7 years for women and 76.8 years for men. Information relating to their falls and subsequent hip fractures were collected. Bone mineral density of the contralateral intact femoral neck was measured using dual energy X-ray absorptiometry (Model XR26, Norland Corporation, USA). Bone mineral density in the patients with hip fracture (mean value 0.55 g/cm2) was significantly lower than the fracture threshold value of 0.64 g/cm2. Falls which would result in direct impact on the hip such as sideways, backwards and straight down formed 95.6% of the cohort. Forty-six (17.7%) of the patients fell from a seated or lying position and their bone mineral density were significantly lower (i.e. 0.45 g/cm2). Two hundred and twenty-three (85.7%) of the patients fell on hard surfaces such as ceramic, marble and concrete. Two hundred and twelve (81.5%) of the falls occurred indoors and 153 (58.8%) while walking. Low bone mineral density and falls are important risk factors in hip fracture in the elderly population. Patients with low bone mineral density can sustain a hip fracture from mild trauma such as falling from a seated or lying position. It is therefore necessary to monitor bone mineral density values as well as to prevent or minimise the risk of falling.

Osteoid osteoma in a three-year-old child--a case report.

Osteoid osteoma is an uncommon tumour in the very young. We present a case of osteoid osteoma in a three-year-old boy, who was treated as a case of sclerosing osteomyelitis of the femur. Because of persistent pain and lack of response to treatment, further radiological investigation confirmed the diagnosis to be that of an osteoid osteoma.

Pyogenic arthritis of the hip following an occult open fracture of the pubic rami--a case report.

Most of the open pelvic fractures are associated with skin wounds of varying anatomy. Injuries of the pelvis, which only momentarily communicate with the exterior or into a hollow organ are often difficult to diagnose. We managed a patient with an occult open displaced fracture of the public rami that had probably torn the hip capsule and was not recognised on admission as the open wound was in the vaginal wall. It subsequently resulted in septic arthritis of the ipsilateral hip joint. Vaginal and rectal examination in grossly displaced pelvic fractures should be done to diagnose at an early stage any occult open wound which may pose high risk of contamination of the fracture site.

Cystoscopy in cases of carcinoma of the cervix uteri: clinical experience with 85 cases.

A retrospective study involving 85 cases of cystoscopy carried out between December, 1989 and July, 1992 in selected cases of carcinoma cervix was undertaken with the purpose of determining the place of cystoscopy in this condition. Cystoscopy was performed only when there was a clinical suspicion of the urinary bladder being involved. Of 67 cases in which cystoscopy was performed as part of staging of carcinoma cervix, one was in stage II, 48 in stage III and 18 in stage IV (stages determined prior to cystoscopy). On cystoscopy of the stage III cases, 50% showed apparent involvement of bladder, 29.17% showed suspicious findings and 20.83% showed negative findings. Of the stage IV cases, 61.11% showed apparent involvement of bladder, 33.33% showed suspicious findings and 5.56% showed negative findings. Of 13 cases in which biopsy was taken cystoscopically, 8 were histologically positive, 4 were histologically negative and one was histologically suspicious for malignancy of the urinary bladder. In the remaining 18 cases cystoscopy was performed during follow-up period.

Effect of decalcification on bone mineral content and bending strength of feline femur.

The relationships between bone mineral content (BMC), bone calcium, and bone strength were studied in fractionally demineralized feline femurs. In 44 pairs of cat femurs, the right bones were decalcified in ethylene diaminetetra acetic acid (EDTA) to 20%, 40%, 60%, 80%, and 100% of the mineral content of the intact left bone (= control). The bones were then loaded to failure, and maximum strength values were recorded. The data were then used to calculate the percentage strength of the right relative to the left femurs. A correlation coefficient (r) of 0.970 was found between the percentage decalcification and percentage bending strength. A direct relationship (r = 0.876) was also observed between the total calcium extracted and total loss in BMC. The EDTA solutions were spot checked for protein content to determine if the organic matrices had been altered by demineralization. Protein was never detected. Nor did the demineralized tissues display histologic evidence of gross microscopic damage. This study has shown that in cat femurs, 20% decalcification led to about 35% loss in bending strength, and 60% decalcification caused 75% loss in strength. These values are significant as they highlight the importance of calcium to the strength of osteopenic bone.