Global sagittal alignment after surgery of right thoracic idiopathic scoliosis in adolescents and adults with and without thoracic hypokyphosis

The study procedure was conducted in accordance to guidelines approved by the institutional clinical research ethics committee (CREC No. 2016.722) and the Declaration of Helsinki. Written informed consent was obtained from all subjects and their parents before participating in this study.AbstractThis study aimed to characterize global sagittal alignment in adolescent idiopathic scoliosis (AIS) with normal kyphosis (NTK, kyphosis > 10°) and with thoracic hypokyphosis (THK, kyphosis < 10°), before and after posterior spinal fusion, and compare them with asymptomatic controls. 27 AIS girls and young adults with right thoracic curves were included (seventeen with age ≤ 18 years, then age > 21). Biplanar radiographies were acquired at baseline, immediate post-operatively, 1-year and 2-year follow-up, and 3D reconstruction of the spine and pelvis was performed. NTK and THK showed different global sagittal alignment, as well as differences compared to controls. AIS with THK at baseline had higher SVA/SFD (2.0 ± 2.9 vs − 0.4 ± 1.9; P < 0.05) and OD-HA (0.2 ± 1.4° vs − 1.3 ± 1.6°; P < 0.05) than controls, indicating that THK had compensated balance with unusual forward leaning posture. Immediately post-operation, SVA/SFD remained high (1.3 ± 3.0) while OD-HA reversed (− 1.2 ± 1.7°), indicating that THK patients had found partially compensated balance. After 2-yeas, both SVA/SFD (− 1.3 ± 2.1) and OD-HA (− 1.4 ± 0.9°) were normalized. The changes in global sagittal alignment and mechanism of balance are different in AIS with or without THK. As the head plays a critical role on balance during immediate and delayed post-operation, OD-HA can be complementary parameter for assessing global balance during post-operative follow-up of AIS patients with THK.The investigation was fully supported by a grant from the General Research Funding of Hong Kong (Project no. 14206716) (W.C.W.C.), and a funding from the BiomecAM Chair Program on Musculoskeletal Modeling (with the support of Société Générale, Covea, Yves Cotrel Foundation, ParisTech Foundation and Proteor) (C.V.)

Handgrip strength assessment at baseline in addition to bone parameters could potentially predict the risk of curve progression in adolescent idiopathic scoliosis

IntroductionAdolescent idiopathic scoliosis (AIS) is characterized by deranged bone and muscle qualities, which are important prognostic factors for curve progression. This retrospective case–control study aims to investigate whether the baseline muscle parameters, in addition to the bone parameters, could predict curve progression in AIS.MethodsThe study included a cohort of 126 female patients diagnosed with AIS who were between the ages of 12 and 14 years old at their initial clinical visit. These patients were longitudinally followed up every 6 months (average 4.08 years) until they reached skeletal maturity. The records of these patients were thoroughly reviewed as part of the study. The participants were categorized into two sub-groups: the progressive AIS group (increase in Cobb angle of ≥6°) and the stable AIS group (increase in Cobb angle <6°). Clinical and radiological assessments were conducted on each group.ResultsCobb angle increase of ≥6° was observed in 44 AIS patients (34.9%) prior to skeletal maturity. A progressive AIS was associated with decreased skeletal maturity and weight, lower trunk lean mass (5.7%, p = 0.027) and arm lean mass (8.9%, p < 0.050), weaker dominant handgrip strength (8.8%, p = 0.027), deranged cortical compartment [lower volumetric bone mineral density (vBMD) by 6.5%, p = 0.002], and lower bone mechanical properties [stiffness and estimated failure load lowered by 13.2% (p = 0.005) and 12.5% (p = 0.004)]. The best cut-off threshold of maximum dominant handgrip strength is 19.75 kg for distinguishing progressive AIS from stable AIS (75% sensitivity and 52.4% specificity, p = 0.011).DiscussionPatients with progressive AIS had poorer muscle and bone parameters than patients with stable AIS. The implementation of a cut-off threshold in the baseline dominant handgrip strength could potentially be used as an additional predictor, in addition to bone parameters, for identifying individuals with AIS who are at higher risk of experiencing curve progression

Twelve-year follow-up of a case of proximal femoral Unicameral Bone Cyst (UBC) treated by steroid injection using radiological and DXA scan data

This report is of a proximal femoral unicameral bone cyst in a patient presented at 3 years. Intra-lesional steroid injection was used to treat this large active lesion. The response to treatment was monitored with the use of dual-energy X-ray absorptiometry (DXA) scan as an indirect method of monitoring the activity of the bone cyst. The patient had developed stress fracture during the course of treatment which had remodelled fully after successful treatment with multiple injections; at 12-year follow-up, the patient reached skeletal maturity. The affected femur had remodelled back to normal radiological appearance without avascular necrosis. This has demonstrated that steroid injection is a safe and effective procedure to achieve regression of a large active bone cyst in the proximal femur. It is a minimal invasive procedure resulting in no scar. DXA scan is a useful method combining clinical assessment to monitor status of the bone cyst to allow timing of injection. 中文摘要: 本報告為3歲患者的股骨近端骨囊腫，以用病灶內類固醇注射來治療這個巨大的活性病灶。 使用雙能X射線吸收測定法 (DXA) 掃描作為間接方法監測骨囊腫活性對治療的反應。 患者在治療過程中出現了應力性骨折，經多次注射成功治療後已完全改型，隨訪12年，患者達到骨骼成熟。 受影響的股骨已經重新恢復正常的放射學外觀及沒有缺血性壞死。 這證明了類固醇注射是一種安全有效的方法，以實現股骨近端巨大活躍骨囊腫的消退。 這是微創手術，沒有疤痕。 DXA掃描結合臨床評估以監測骨囊腫狀態是有效的方法以允許注射時機。 Keywords: DXA, steroid injection, Unicameral Bone Cys

HR-pQCT for the Evaluation of Muscle Quality and Intramuscular Fat Infiltration in Ageing Skeletal Muscle

Myosteatosis is the infiltration of fat in skeletal muscle during the onset of sarcopenia. The quantification of intramuscular adipose tissue (IMAT) can be a feasible imaging modality for the clinical assessment of myosteatosis, important for the early identification of sarcopenia patients and timely intervention decisions. There is currently no standardized method or consensus for such an application. The aim of this study was to develop a method for the detection and analysis of IMAT in clinical HR-pQCT images of the distal tibia to evaluate skeletal muscle during the ageing process, validated with animal and clinical experimentation. A pre-clinical model of ovariectomized (OVX) rats with known intramuscular fat infiltration was used, where gastrocnemii were scanned by micro-computed tomography (micro-CT) at an 8.4 µm isotropic voxel size, and the images were analyzed using our modified IMAT analysis protocol. IMAT, muscle density (MD), and muscle volume (MV) were compared with SHAM controls validated with Oil-red-O (ORO) staining. Furthermore, the segmentation and IMAT evaluation method was applied to 30 human subjects at ages from 18 to 81 (mean = 47.3 ± 19.2). Muscle-related parameters were analyzed with functional outcomes. In the animal model, the micro-CT adipose tissue-related parameter of IMAT% segmented at −600 HU to 100 HU was shown to strongly associate with the ORO-positively stained area (r = 0.898, p = 0.002). For the human subjects, at an adjusted threshold of −600 to −20 HU, moderate positive correlations were found between MV and MD (r = 0.642, p < 0.001), and between MV and IMAT volume (r = 0.618, p < 0.01). Moderate negative correlations were detected between MD and IMAT% (r = −0.640, p < 0.001). Strong and moderate associations were found between age and MD (r = −0.763, p < 0.01), and age and IMAT (r = 0.559, p < 0.01). There was also a strong correlation between IMAT% and chair rise time (r = 0.671, p < 0.01). The proposed HR-pQCT evaluation protocol for intramuscular adipose-tissue produced MD and IMAT results that were associated with age and physical performance measures, and were of good predictive value for the progression of myosteatosis or sarcopenia. The protocol was also validated on animal skeletal muscle samples that showed a good representation of histological lipid content with positive correlations, further supporting the clinical application for the rapid evaluation of muscle quality and objective quantification of skeletal muscle at the peripheral for sarcopenia assessment

Investigation on the site of coronal deformities in Hallux valgus

Abstract Hallux valgus (HV) is a common foot deformity that is more prevalent in females, characterised by abnormal adduction of the first metatarsal (MT) and valgus deviation of the phalanx on the transverse plane. Increasing evidence indicates that HV is more than a 2D deformity but a 3D one with rotational malalignment. Pronation deformity is seen during clinical examination for HV patients, but the exact origin of this rotational deformity is still unknown. Some attribute it to first tarsometatarsal (TMT) joint rotation, while others attribute it to intra-metatarsal bony torsion. In addition, the correlation between the rotational and transverse plane deformity is inconclusive. Identifying the origin of the rotational deformity will help surgeons choose the optimal surgical procedure while also enhancing our understanding of the pathophysiology of HV. This study aims to (1) develop an objective method for measuring the first MT torsion and first TMT joint rotation; (2) investigate the exact location of the coronal deformity in HV; (3) investigate the relationship between the severity of deformity on the transverse and coronal planes as well as the correlation between deformity severity and foot function/symptoms in HV. Age-matched females with and without HV were recruited at the Foot and Ankle Clinic of the Department of Orthopaedics and Traumatology. Computed tomography was conducted for all subjects with additional weight-bearing dorsal-plantar X-ray examination for HV subjects. Demographic information of all subjects was recorded, with symptoms and functions related to HV evaluated. The intra-class correlation was used to explore the relationship between deformities on different planes and the deformity severity and functional outcomes, respectively. An Independent t-test was used to compare joint rotation and bone torsion degrees. TMT joint rotation is significantly correlated with foot function. HV patients had more TMT joint rotation but not MT torsion compared to normal controls. No relationship was found between the coronal rotation and the 1,2-intermetatarsal angle (IMA) or Hallux valgus angle (HVA) on the transverse plane. Our results indicate that coronal deformities in HV may originate from TMT joint rotation. In addition, the severity of the TMT joint coronal rotation correlates with worse foot function; thus, multi-plane assessment and examination will be necessary for more precise surgical correction

Sexual dimorphism in cortical and trabecular bone microstructure appears during puberty in chinese children

Distal forearm fractures during growth are more common in males than females. Because metaphyseal cortical bone is formed by coalescence of trabeculae emerging from the periphery of the growth plate, we hypothesized that the later onset of puberty in males produces a longer delay in trabecular bone formation and coalescence, which leaves a transient phase of high cortical porosity, low matrix mineral density, and high trabecular density relative to females. We quantified the nondominant distal radial microstructure using high‐resolution peripheral quantitative computed tomography in 214 healthy Chinese boys and 219 Chinese girls aged between 7 and 17 years living in Hong Kong. Measurements of 110 slices (9.02 mm) were acquired 5 mm proximal to the growth plate of the nondominant distal radius. Porosity was measured using StrAx1.0 (Straxcorp, Melbourne, VIC, Australia) and trabecular plate and rod structure were measured using individual trabecula segmentation (ITS). Mechanical properties were estimated using finite element analysis (FEA). Results were adjusted for age, total bone cross‐sectional area (CSA), dietary calcium intake, and physical activity. In boys, total bone CSA was 17.2% to 22.9% larger throughout puberty, cortical/total bone CSA was 5.1% smaller in Tanner stage 2 only, cortical porosity was 9.4% to 17.5% higher, and matrix mineral density was 1.0% to 2.5% lower in Tanner stage 2 to 5, than girls. Boys had higher trabecular rod BV/TV in Tanner stage 3 and 4, but higher trabecular plate BV/TV and plate to rod ratio in Tanner stage 5, than girls. Boys had 17.0% lower apparent modulus than girls in Tanner stage 2. A transient phase of higher porosity due to dissociation between bone mineral accrual and linear growth may contribute to higher distal radial bone fragility in Chinese boys compared to girls. © 2018 American Society for Bone and Mineral Research

13Th International Conference On Conservative Management Of Spinal Deformities And First Joint Meeting Of The International Research Society On Spinal Deformities And The Society On Scoliosis Orthopaedic And Rehabilitation Treatment – Sosort-Irssd 2016 Meeting

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