Tsz Ping Lam

Epidemiological features of supracondylar fractures of the humerus in Chinese children

We studied 450 children with a supracondylar fracture of the humerus in the period 1991 to 1995, and were able to collect full management details in 403 of them (253 boys and 150 girls). The median age at presentation was 6 years (6.6 years in boys, and 5 years in girls), with the nondominant humerus 1.5 times more commonly injured. Fifteen percent of children presented more than 1 day after the injury. Garland type III fractures constituted 45% of cases, type I 30%, and type II 24%, with flexion type fractures present only in 1% of the children. A nerve injury was associated with the fracture in 19 cases. Although the radial pulse was not palpable at presentation in nine patients, only one child had diminished distal circulation requiring exploration. Concomitant fractures were present in 14 patients. Elbow hyperextension was greater than in a comparable group of noninjured children. Open reduction was necessary in 20% of these children, most being managed by manipulation under anaesthesia, at times associated with percutaneous Kirschner wiring. The hospital stay was 2 days or less in two-thirds of the patients, with more than 90% discharged home within 1 week of admission. In conclusion, many Chinese patients attend hospital later than their Western counterparts, and the rate of flexion-type injuries is low.

A meta-analysis of the clinical effectiveness of school scoliosis screening

Study Design. A meta-analysis that systematically reviewed the evaluation studies of a scoliosis screening program reported in the literature. Objective. To evaluate the best current evidence on the clinical effectiveness of school screening for adolescent idiopathic scoliosis. Summary of Background Data. The use of school scoliosis screening is controversial, and its clinical effectiveness has been diversely reported. Methods. Data sources included 3 databases, namely, PubMed, Google scholar, CINAHL database, and the references from identified reviews and studies. Studies were included if: (1) they adopted a retrospective cohort design; (2) were screened using either the forward bending test (FBT), angle of trunk rotation, or Moiré topography; (3) reported results of screening tests and radiographic assessments; (4) screened adolescents only; (5) reported the incidence of curves with a minimum Cobb angle of 10° or greater; and (6) reported the number of referrals for radiography. Reviews, comments, case studies, and editorials were excluded. Results. Thirty-six studies, including 34 from the 775 initially identified studies and 2 from the references, met the selection criteria. The pooled referral rate for radiography was 5.0%, and the pooled positive predictive values for detecting curves ≥10°, curves ≥20°, and treatment were 28.0%, 5.6%, and 2.6%, respectively. There was substantial heterogeneity across studies. Meta-regression showed that programs using the FBT alone reported a higher referral rate (odds ratio [OR] = 2.91) and lower positive predictive values for curves ≥10° (OR = 0.49) and curves ≥20° (OR = 0.34) than programs using other tests. Only one small study followed students until skeletal maturity and reported the sensitivity of screening; however, the specificity was not reported. No severe publication bias was noted. Conclusion. The use of the FBT alone in school scoliosis screening is insufficient. We need large, retrospective cohort studies with sufficient follow-up to properly assess the clinical effectiveness of school scoliosis screening.

The effect of rigid versus flexible spinal orthosis on the clinical efficacy and acceptance of the patients with adolescent idiopathic scoliosis.

Study Design. A prospective study on the comparison of the clinical efficacy and patient’s acceptance of the 2 orthotic management methods. Objective. To compare the treatment effectiveness and patients’ acceptance of the flexible spinal orthosis, SpineCor with that of the rigid spinal orthosis for the patients with moderate adolescent idiopathic scoliosis. Summary of Background Data. The patients’ acceptance to the rigid spinal orthoses is always a concern as it could greatly affect the clinical outcome. SpineCor is a relatively new design for tackling those inevitable drawbacks found in rigid orthosis. However, there was no study to compare this design with the conventional method regarding their treatment efficacy and the patient’s acceptance. Methods. Forty-three subjects with moderate adolescent idiopathic scoliosis were randomly assigned to the SpineCor group (S group, n = 22) and rigid orthosis group (R group, n = 21). Their survival rate in the first 45 months of intervention was studied. The subjects’ acceptance to the orthoses was evaluated by a purpose-designed questionnaire, which was administered in the 3rd, 9th, and 18th months of intervention. Results. In the study period, there were 68% of the subjects in the S group and 95% of the subjects in the R group did not show curve progression. Significant difference (P = 0.046, by Fisher exact test) in failure rate between the 2 subject groups was found although the 2 groups had similar responses to the questionnaire. Conclusion. The current study showed that the failure rate of the SpineCor was significantly higher than that of the rigid spinal orthosis, and the patients’ acceptance to the SpineCor was comparable to the conventional rigid spinal orthosis.

Percutaneous transphyseal intramedullary Kirschner wire pinning: a safe and effective procedure for treatment of displaced diaphyseal forearm fracture in children.

Percutaneous transphyseal intramedullary Kirschner wire (K-wire) fixation was performed for diaphyseal fracture of the forearm in 84 children. In 60 patients (71%) closed reduction was performed, while in the remaining 24 (29%) closed reduction was supplemented with a mini-open reduction The K-wire was inserted transphyseally through the radial styloid or the Lister tubercle for the radius, and through the tip of the olecranon for the ulna. With an average follow-up of 70 months and a minimum follow-up of 2 years, all the patients reviewed were found to have good functional results; none had nonunion, deep infection, or premature physeal closure. Moreover, initial preoperative translation of the fracture of more than 100% displacement was found to be associated with a significantly higher chance of requiring a mini-open reduction. The authors concluded that percutaneous transphyseal intramedullary K-wire pining for forearm diaphyseal fracture in children is a convenient, effective, and safe operation, without any deleterious effects on subsequent growth of the distal radius.

Abnormal Bone Quality in Adolescent Idiopathic Scoliosis : A Case-Control Study on 635 Subjects and 269 Normal Controls With Bone Densitometry and Quantitative Ultrasound

Study Design. A case-control study comparing bone quality in Adolescent Idiopathic Scoliosis (AIS) with normal controls. Objective. To evaluate bone quality with quantitative ultrasound (QUS) in AIS and normal controls so as to detect any derangement in bone quality among AIS subjects. Summary of Background Data. AIS is characterized by complex spinal deformities. Despite its high prevalence and clinical impact in adolescents, etiology of AIS remains unknown but one possible mechanism is related to derangement of bony mechanical stability, as quantified by bone mineral density (BMD) and bone quality. AIS is known for its association with osteopenia, but little is known about the bone quality in AIS. With technological advancement, QUS can provide objective measurement of bone quality. In this study, we sought to compare bone quality in AIS with normal controls using QUS in addition to the conventional BMD measurement. Methods. Six hundred thirty-five AIS girls and 269 age-matched normal girls were investigated. Broadband ultrasound attenuation (BUA), velocity of sound (VOS), and stiffness index (SI) were measured over the nondominant calcaneus using QUS. The results were correlated with anthropometric measurement, radiologic assessment, and BMD of both hips. Results. The z-score of BMD at the femoral neck of AIS subjects (−0.47 ± 0.97) was significantly lower than that of normal controls (−0.12 ± 1.01, P < 0.001). Crude comparison showed that BUA, VOS, and SI of AIS group were 3.8% (P < 0.01), 0.5% (P = 0.042), and 6.9% (P < 0.01) lower than controls, respectively. After controlling confounding from maturity, body weight, body height, and BMD with multiple linear regression analysis for both mild (Cobbs angle ⩽ 25°) and severe (Cobbs angle > 25°) curves, BUA and SI were found to be statistically significantly lower in AIS as compared with controls (P < 0.05). Conclusion. In addition to higher prevalence of osteopenia, AIS patients were also found to have deranged bone quality. These might contribute to the etiopathogenesis of spinal deformities in AIS.

Bone structural and mechanical indices in Adolescent Idiopathic Scoliosis evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT).

Adolescent Idiopathic Scoliosis (AIS) is associated with systemic low bone mass. It could persist into adulthood and was shown to be an important prognostic factor for curve progression in AIS. Previous studies were confined to areal bone mineral density (aBMD) measured by Dual-energy X-ray Absorptiometry (DXA) which was a two-dimensional measurement for a three-dimensional structure. This conventional measurement was inadequate to evaluate volumetric bone density and bone quality which are important determinants for bone strength and bone health status as defined in the 2000 NIH consensus statement. High-resolution peripheral quantitative computed tomography (HR-pQCT) was therefore used in this study for three-dimensional evaluation of volumetric bone mineral density and bone micro-architecture as well as estimation of bone strength. In this study, 214 newly diagnosed AIS girls and 187 age and gender-matched normal control aged between 11 and 13years old were recruited for HR-pQCT evaluations on bone geometry, trabecular bone micro-architecture and volumetric BMD (vBMD) at the non-dominant distal radius. We demonstrated that AIS was associated with lower Cortical Bone Area, Cortical Bone vBMD, Trabecular Number and greater Trabecular Separation. With multivariate linear regression analysis and after adjustment for age, dietary calcium intake and physical activity level, the association of AIS with lower Cortical Bone vBMD, lower Trabecular Number and greater Trabecular Separation remained statistically significant. The findings of this study indicated that AIS was associated with an abnormal bone quality profile suggestive of alteration in endocortical modeling, derangement in trabecular bone structure and disturbance in bone mineralization. The cause for these changes and how they are related to the etiopathogenesis of AIS warrant further studies.

Prognosis and prognostic factors of Legg-Calve-Perthes disease.

This is an overall review of the published literature in the past 100 years on the prognosis and prognostic factors of Legg-Calve-Perthes disease (LCPD). There were considerable limitations and inadequacies of the reported series. LCPD is not a common disease, and thus most reports were based on relatively small series collected retrospectively over a long period of time without clearly defined case selection, assessment, treatment, follow-up period, and outcome measures. Few studies, if any, would satisfy the strict definition of prognosis, which should only mean those prognostic factors derived from observation of the natural history of the disease-that is the uninterrupted progressive development of a disease that runs its course from onset-inception to resolution without any intervention or treatment. This review attempted to summarize from the mixed series of studies the generally described demographic, clinical, and radiologic prognostic factors of LCPD. The most important radiologic prognostic signs include the extent of femoral capital epiphysis involvement, the degree of metaphyseal changes, and lateral subluxation of femoral head and depend significantly on the time of assessment after the onset of the disease. More detailed discussions on prognostication based on the structured classification systems that have evolved in the past few decades would be described.

A population-based cohort study of 394,401 children followed for 10 years exhibits sustained effectiveness of scoliosis screening

BACKGROUND CONTEXT The value of scoliosis screening has been recently shown in a multicenter randomized controlled trial. However, the long-term sustainability of the clinical effectiveness of scoliosis screening as a routine health service remains unknown. PURPOSE The aim of this study was to assess the sustainability of the clinical effectiveness of school scoliosis screening. STUDY DESIGN/SETTING A large population-based cohort study with a 10-year follow-up was conducted. PATIENT SAMPLE A total of 394,401 students who were in the fifth grade during the five academic years from 1995/1996 to 1999/2000 formed five consecutive annual cohorts. The students were eligible for the Hong Kong scoliosis screening program, with their screening history and medical records until their nineteenth birthdays being assessed. OUTCOME MEASURES The outcome measures considered in the study were development of adolescent idiopathic scoliosis by the 19 years of age and the Cobb angle. METHODS The clinical effectiveness of scoliosis screening was assessed by referral rate for radiographic diagnosis, sensitivity, specificity, and predictive values. RESULTS A total of 306,144 students (78%) participated in scoliosis screening, which used a two-tier system. The prevalence of curves of 20° or greater was 1.8% (95% confidence interval [CI], 1.7-1.8%), whereas the referral rate for radiography, the sensitivity, and the positive predictive value (PPV) for curves of 20° or greater were 4.1% (95% CI, 4.0-4.2%), 91% (95% CI, 90-92%), and 40% (95% CI, 39-41%), respectively. Across the five consecutive annual cohorts, the prevalence and sensitivity for curves of 20° or greater increased by 0.23% (95% CI, 0.21-0.25%; p<.001) and 0.76% (95% CI, 0.43-1.04%; p<.001) per year, respectively; however, the PPV was reduced by 1.71% (95% CI, 1.09-2.33%; p<.001) per year. CONCLUSIONS This report describes the first large population-based study with a long-term follow-up indicating that a scoliosis screening program can have sustained clinical effectiveness in identifying patients with adolescent idiopathic scoliosis needing clinical observation. As the prevalence of adolescent idiopathic scoliosis increases, scoliosis screening should be continued as a routine health service in schools or by general practitioners if there is no scoliosis screening policy.

Quantitative Ultrasound for Predicting Curve Progression in Adolescent Idiopathic Scoliosis: A Prospective Cohort Study of 294 Cases Followed-Up Beyond Skeletal Maturity

Adolescent idiopathic scoliosis (AIS) is prevalent among adolescents and can carry significant morbidities. We evaluated the use of quantitative ultrasound (QUS) for predicting curve progression in patients with AIS. We recruited 294 girls with AIS at a mean age of 13.4 years, and they were prospectively followed beyond skeletal maturity for curve progression. We recorded 3 calcaneal QUS measurements at baseline, namely broadband ultrasound attenuation (BUA), velocity of sound (VOS), and stiffness index (SI). Logistic regression analysis indicated that SI, age, menarchal status, and Cobb angle were significant prognostic factors to be included in the final prediction model. The adjusted odds ratio of curve progression for Z-score of SI≦0 was 2.00 (95% CI: 1.08-3.71). The area under the ROC curve was 0.831 (95% CI: 0.785-0.877). The results of this study indicate that SI was an independent and significant prognostic factor for AIS and could be considered in addition to other prognostic factors when estimating the risk for curve progression and planning treatment for patients with AIS.

Sunlight Exposure and Breast Density: A Population-Based Study

Purpose This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabárs mammographic pattern in Chinese women. Methods A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabárs classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders. Results Among 646 participants, women with high breast cancer risk (Tabárs patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabárs pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. <1.32 hr/day). For hours spent in the sun across the ages of 6 to 12 years, the comparable OR was 0.37 (95% CI, 0.15-0.91; p for trend=0.03). Conclusion These findings suggest that higher sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life.