Ontogenetic changes to bone microstructure in an archaeologically derived sample of human ribs.

There is considerable variation in the gross morphology and tissue properties among the bones of human infants, children, adolescents, and adults. Using 18 known-age individuals (nfemale  = 8, nmale  = 9, nunknown  = 1; birth to 21 years old), from a well-documented cemetery collection, Spitalfields Christ Church, London, UK, this study explores growth-related changes in cortical and trabecular bone microstructure. Micro-CT scans of mid-shaft middle thoracic ribs are used for quantitative analysis. Results are then compared to previously quantified conventional histomorphometry of the same sample. Total area (Tt.Ar), cortical area (Ct.Ar), cortical thickness (Ct.Th), and the major (Maj.Dm) and minor (Min.Dm) diameters of the rib demonstrate positive correlations with age. Pore density (Po.Dn) increases, but age-related changes to cortical porosity (Ct.Po) appear to be non-linear. Trabecular thickness (Tb.th) and trabecular separation (Tb.Sp) increase with age, whereas trabecular bone pattern factor (Tb.Pf), structural model index (SMI), and connectivity density (Conn.D) decrease with age. Sex-based differences were not identified for any of the variables included in this study. Some samples display clear evidence of diagenetic alteration without corresponding changes in radiopacity, which compromises the reliability of bone mineral density (BMD) data in the study of past populations. Cortical porosity data are not correlated with two-dimensional measures of osteon population density (OPD). This suggests that unfilled resorption spaces contribute more significantly to cortical porosity than do the Haversian canals of secondary osteons. Continued research using complementary imaging techniques and a wide array of histological variables will increase our understanding of age- and sex-specific ontogenetic patterns within and among human populations.

Effect on the offspring of pregnant females CD-1 mice treated with a single thallium(I) application.

Thallium (Tl) is a highly toxic metal for human beings; higher amounts found in diverse fluids of pregnant women are associated with low birth weight and preterm birth. However, experimental data concerning their effects on the embryonic development of mammalian organisms are limited. Hence, in the present work, TI(I) acetate of 0, 4.6, 9.2, or 18.5 mg/kg body weight were administered by intraperitoneal injection to groups of 10 pregnant CD-1 mice on the 7th gestational day, and animals were sacrificed on day 18 of gestation. The fetuses obtained showed some variations, such as trunk bent over (18.5 mg/kg), tail variations (all doses), forelimbs malrotation and hind limbs (all doses). Skeletal examination of the fetuses showed a delay in the ossification of skull bones, ribs, and limbs (all doses). In conclusion, the Intraperitoneal injection of Tl(I) acetate to pregnant mice induced morphological variations and a delay of the fetus ossification.

Scleraxis genes are required for normal musculoskeletal development and for rib growth and mineralization in zebrafish.

Tendons are an essential part of the musculoskeletal system, connecting muscle and skeletal elements to enable force generation. The transcription factor scleraxis marks vertebrate tendons from early specification. Scleraxis-null mice are viable and have a range of tendon and bone defects in the trunk and limbs but no described cranial phenotype. We report the expression of zebrafish scleraxis orthologs: scleraxis homolog (scx)-a and scxb in cranial and intramuscular tendons and in other skeletal elements. Single mutants for either scxa or scxb, generated by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), are viable and fertile as adult fish. Although scxb mutants show no obvious phenotype, scxa mutant embryos have defects in cranial tendon maturation and muscle misalignment. Mutation of both scleraxis genes results in more severe defects in cranial tendon differentiation, muscle and cartilage dysmorphogenesis and paralysis, and lethality by 2-5 wk, which indicates an essential function of scleraxis for craniofacial development. At juvenile and adult stages, ribs in scxa mutants fail to mineralize and/or are small and heavily fractured. Scxa mutants also have smaller muscle volume, abnormal swim movement, and defects in bone growth and composition. Scleraxis function is therefore essential for normal craniofacial form and function and vital for fish development.-Kague, E., Hughes, S. M., Lawrence, E. A., Cross, S., Martin-Silverstone, E., Hammond, C. L., Hinits, Y. Scleraxis genes are required for normal musculoskeletal development and for rib growth and mineralization in zebrafish.

Sox9+ messenger cells orchestrate large-scale skeletal regeneration in the mammalian rib.

Most bones in mammals display a limited capacity for natural large-scale repair. The ribs are a notable exception, yet the source of their remarkable regenerative ability remains unknown. Here, we identify a Sox9-expressing periosteal subpopulation that orchestrates large-scale regeneration of murine rib bones. Deletion of the obligate Hedgehog co-receptor, Smoothened, in Sox9-expressing cells prior to injury results in a near-complete loss of callus formation and rib bone regeneration. In contrast to its role in development, Hedgehog signaling is dispensable for the proliferative expansion of callus cells in response to injury. Instead, Sox9-positive lineage cells require Hh signaling to stimulate neighboring cells to differentiate via an unknown signal into a skeletal cell type with dual chondrocyte/osteoblast properties. This type of callus cell may be critical for bridging large bone injuries. Thus despite contributing to only a subset of callus cells, Sox9-positive progenitors play a major role in orchestrating large-scale bone regeneration. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).

Induction of a thoracolumbar supernumerary rib in rat developmental toxicity studies: A short discussion on the critical window.

Thoracolumbar supernumerary ribs (TSRs) are classified as less severe skeletal anomalies in rat developmental toxicity studies, although their incidence is relatively high in rodent studies. To investigate the characteristics of the critical window for chemically-induced TSR, in this study, rats were administered 5-fluorocytocine (5-FC) or sodium salicylate (SAL) at one of three time periods on gestational day (GD) 9, early morning (7:00 am), midday (12:00 pm to 1:00 pm), or late afternoon (4:00 pm or 7:00 pm). The incidence of TSR and other anomalies were assessed in GD20 fetuses. A single treatment with both chemicals on GD9-induced TSR, with the incidence highest when administered at 7:00 Am, decreasing gradually when administered later. This trajectory was clearer in rats treated with 5-FC than with SAL. The critical period of TSR induction is shorter in rats administered 5-FC than SAL. The characteristics of the critical window may cause variability in the incidence of TSR observed in developmental toxicity studies.

Ontogeny of the Postcranial Axial Skeleton of Melanosuchus niger (Crocodylia, Alligatoridae).

This study proposes the description of the development of the postcranial axial skeleton, including vertebrae, gastralium, ribs, sternum, and interclavicle, in Melanosuchus niger. Six nests were marked and two eggs removed from each nest at 24-hr intervals until hatching. For posthatching evaluation, 30 hatchlings were kept in captivity and one exemplar was euthanized at three-day intervals. Samples were diaphanized using potassium hydroxide (KOH), alizarin red S, and Alcian blue. A routinely generally used method was applied for histological evaluation. It was difficult to define in which vertebrae the development of cartilaginous centers began, but it was possible to observe that this condensation advanced in the craniocaudal direction. The condensation started in the vertebral arches and was visibly stronger in the cervical and dorsal regions, advancing to the lumbar, sacral and, last, to the caudal region. The atlas showed a highly different morphology compared with the other cervical vertebrae, with a short intercenter, two neural arches, and a proatlas. The ossification process began in the body of cervical vertebrae III to VIII and alizarin retention decreased in the last vertebrae, indicating a craniocaudal direction in bone development, similar to cartilage formation. In the histological sections of gastralium and interclavicles of M. niger at several development stages, it was possible to observe that these elements showed intramembranous development. Anat Rec, 301:607-623, 2018. © 2017 Wiley Periodicals, Inc.

Age estimation by chest plate radiographs in a Thai male population.

Costal cartilage ossification on chest plate radiographs is one of the useful methods in age estimation for adults. This study was performed in 136 remains yielding a regression formula for age estimation in Thai male population. Eight features on chest plate imaging were scored based on Garvin's method. Composite scores were calculated by summation of all scores and analyzed to generate the regression of age as: Age=16.664×e0.161 (composite score) with a 95% prediction interval. The predicted age intervals in all composite scores were overlapping except for score 0 and 7. It could be concluded that if all features are absent/present, the person is likely to be less/more than 29years old.

Comparative proteomics analysis of teleost intermuscular bones and ribs provides insight into their development.

BACKGROUND: Intermuscular bones (IBs) and ribs both are a part of skeletal system in teleosts, but with different developing process. The chemical composition of fish IBs and ribs as well as the underlying mechanism about their development have not been investigated. In the present study, histological structures showed that one bone cavity containing osteoclasts were existed in ribs, but not in IBs of Megalobrama amblycephala. We constructed the first proteomics map for fish bones including IBs and ribs, and identified the differentially expressed proteins between IBs and ribs through iTRAQ LC-MS/MS proteomic analysis. RESULTS: The proteins extracted from IBs and ribs at 1- to 2-year old M. amblycephala were quantified 2,342 proteins, with 1,451 proteins annotated with GO annotation in biological processes, molecular function and cellular component. A number of bone related proteins as well as pathways were identified in the study. A total of 93 and 154 differently expressed proteins were identified in comparison groups of 1-IB-vs-1-Rib and 2-IB-vs-2-Rib, which indicated the obvious differences of chemical composition between these two bone tissues. The two proteins (vitronectin b precursor and matrix metalloproteinase-2) related to osteoclasts differentiation were significantly up-regulated in ribs compared with IBs (P < 0.05), which was in accordance with the results from histological structures. In comparison groups of 1-IB-vs-2-IB and 1-Rib-vs-2-Rib, 33 and 51 differently expressed proteins were identified and the function annotation results showed that these proteins were involved in regulating bone development and differentiation. Subsequently, 11 and 13 candidate proteins in comparison group of 1-IB-vs-1-Rib and 1-IB-vs-2-IB related to bone development were validated by MRM assays. CONCLUSIONS: Our present study suggested the different key proteins involved in the composition of fish ribs and IBs as well as their growth development. These findings could provide important clues towards further understanding of fish skeletal system and the roles of proteins playing in regulating diverse biological processes in fish.

Cerebro-costo-mandibular syndrome: Clinical, radiological, and genetic findings.

Cerebro-Costo-Mandibular syndrome (CCMS) is a rare autosomal dominant condition comprising branchial arch-derivative malformations with striking rib-gaps. Affected patients often have respiratory difficulties, associated with upper airway obstruction, reduced thoracic capacity, and scoliosis. We describe a series of 12 sporadic and 4 familial patients including 13 infants/children and 3 adults. Severe micrognathia and reduced numbers of ribs with gaps are consistent findings. Cleft palate, feeding difficulties, respiratory distress, tracheostomy requirement, and scoliosis are common. Additional malformations such as horseshoe kidney, hypospadias, and septal heart defect may occur. Microcephaly and significant developmental delay are present in a small minority of patients. Key radiological findings are of a narrow thorax, multiple posterior rib gaps and abnormal costo-transverse articulation. A novel finding in 2 patients is bilateral accessory ossicles arising from the hyoid bone. Recently, specific mutations in SNRPB, which encodes components of the major spliceosome, have been found to cause CCMS. These mutations cluster in an alternatively spliced regulatory exon and result in altered SNRPB expression. DNA was available from 14 patients and SNRPB mutations were identified in 12 (4 previously reported). Eleven had recurrent mutations previously described in patients with CCMS and one had a novel mutation in the alternative exon. These results confirm the specificity of SNRPB mutations in CCMS and provide further evidence for the role of spliceosomal proteins in craniofacial and thoracic development.

Rib overgrowth may be a contributing factor for pectus excavatum: Evaluation of prepubertal patients younger than 10years old.

BACKGROUND/PURPOSE: We compared the costal cartilage and rib length between prepubertal patients with symmetric pectus excavatum and age- and sex-matched controls without anterior chest wall depression to evaluate if rib overgrowth is a contributing factor for pectus excavatum METHODS: The sample included 18 prepubertal patients <10years old with symmetric pectus excavatum and 18 age-and sex-matched controls without chest wall deformity. The full lengths of the fourth to sixth ribs and costal cartilage were measured using three-dimensional volume-rendered computed tomography and curved multiplanar reformatting techniques. The rib and costal cartilage lengths, total combined rib and costal cartilage length, and costal index ([length of cartilage/length of rib]×100 [%]) at the fourth to sixth levels were compared between the groups. RESULTS: The rib lengths in the patient group were significantly longer than in the control group for the 6th right rib and 4th, 5th, and 6th left ribs. The costal cartilage lengths and costal indices were not different between two groups. CONCLUSIONS: In patients with symmetric pectus excavatum aged <10years old, several of the ribs were longer than those of controls, suggesting that abnormal rib overgrowth may be a contributing factor responsible for pectus excavatum rather than cartilage overgrowth.

Rib Cartilage Assessment Relative to the Healthy Ear in Young Children with Microtia Guiding Operative Timing.

BACKGROUND: The optimal age at which to initiate for auricular reconstruction is controversial. Rib cartilage growth is closely related to age and determines the feasibility and outcomes of auricular reconstruction. We developed a method to guide the timing of auricular reconstruction in children with microtia ranging in age from 5 to 10 years. METHODS: Rib cartilage and the healthy ear were assessed using low-dose multi-slice computed tomography. The lengths of the eighth rib cartilage and the helix of the healthy ear (from the helical crus to the joint of the helix and the earlobe) were measured. Surgery was performed when the two lengths were approximately equal. RESULTS: The preoperative eighth rib measurements significantly correlated with the intraoperative measurements (P < 0.05). From 5 to 10 years of age, eighth rib growth was not linear. In 76 (62.8%) of 121 patients, the eighth rib length was approximately equal to the helix length in the healthy ear; satisfactory outcomes were achieved in these patients. In 18 (14.9%) patients, the eighth rib was slightly shorter than the helix, helix fabrication was accomplished by adjusting the length of the helical crus of stent, and satisfactory outcomes were also achieved. Acceptable outcomes were achieved in 17 (14.0%) patients in whom helix fabrication was accomplished by cartilage splicing. In 9 (7.4%) patients with insufficient rib cartilage length, the operation was delayed. In one (0.8%) patient with insufficient rib cartilage length, which left no cartilage for helix splicing, the result was unsatisfactory. CONCLUSIONS: Eighth rib cartilage growth is variable. Rib cartilage assessment relative to the healthy ear can guide auricular reconstruction and personalize treatment in young patients with microtia.

A Cross-Sectional Study of Chest Wall Development in Patients with Pectus Excavatum.

BACKGROUND: We conducted a cross-sectional study to quantify the developmental changes of the thoracic cage in patients with pectus excavatum (PE). METHODS: The preoperative posteroanterior standing chest radiographs (chest PAs) of 1,197 consecutive patients with PE, together with 1,661 age- and sex-matched minor surgery patients, as a control group, who were seen between June 2005 and February 2013, were reviewed. The maximum width of each rib pair and chest height (H) were measured on the chest PA. RESULTS: In the PE group, the normal thoracic contour in younger patients was replaced by a characteristic can-shaped chest wall, which showed protrusion of the upper ribs, an increased H, and a straightened lateral border of the chest cage, as they grew into adulthood. The chest height difference between the PE and control groups increased progressively, from the age of 8 years and most significantly from age 13 to 17 years. No difference was observed in the middle and lower rib widths. Sex did not influence these trends. CONCLUSION: The PE chest wall shows a significant increment in chest height, and upper rib width starts during the period of rapid growth and is maintained into adulthood. The thoracic deformity in patients with PE includes more than just the sternal deformity.

Asymmetric Pectus Excavatum Is Associated with Overgrowth of Ribs Rather Than Cartilage.

BACKGROUND: To evaluate whether the overgrowth of costal cartilage exists in patients with pectus excavatum, we compared the length of the costal cartilage and ribs between patients with asymmetric pectus excavatum and controls without chest wall deformity using three-dimensional computed tomography. MATERIALS AND METHODS: Nineteen adult patients with asymmetric pectus excavatum and 19 age and sex matched controls without chest wall deformity were enrolled. We measured the full lengths of the fourth to sixth ribs and costal cartilage using three-dimensional volume-rendered computed tomography images and curved multiplanar reformatting techniques. The lengths of ribs and costal cartilage, their summations, and the costal index ([length of cartilage/length of rib] × 100 [%]) were compared on the asymmetrically depressed side of patients (Group A), the opposite side of the same patients (Group B), and controls (Group C) at the fourth to sixth levels. RESULTS: The lengths of the ribs of groups A and B were significantly longer (p < 0.001) than those of group C (299.4 ± 14.9 mm vs. 302.9 ± 15.3 mm vs. 288.9 ± 12.2 at the fourth level, 312.3 ± 14.1 mm vs. 318.4 ± 14.6 mm vs. 303.2 ± 12.7 mm at the fifth level, and 322.2 ± 17.2 mm vs. 325.2 ± 17.5 mm vs. 309.4 ± 12.3 mm at the sixth level). The costal cartilage lengths did not differ (p > 0.05) among the three groups (53.1 ± 7.3 mm vs. 54.6 ± 8.6 mm vs. 52.9 ± 5.2 at the fourth level, 71.9 ± 9.6 mm vs. 72.3 ± 9.9 mm vs. 69.2 ± 7.1 mm at the fifth level, and 100.1 ± 15.2 mm vs. 104.2 ± 15.8 mm vs. 99.1 ± 9.1 mm at sixth level). The summations of the rib and costal cartilage lengths were longer in groups A and B than in group C. The costal indices were not different among the three groups at the fourth, fifth, and sixth rib levels. CONCLUSION: In patients who had asymmetric pectus excavatum with a ≥ 21-degree angle of sternal rotations, the ribs but not the costal cartilage were longer than those of controls. These findings suggest that cartilage overgrowth is not the main factor responsible for asymmetric pectus excavatum, and it could instead be related to abnormal rib growth.

The etiology of pectus carinatum involves overgrowth of costal cartilage and undergrowth of ribs.

PURPOSE: We compared the length of costal cartilage and rib between patients with symmetric pectus carinatum and controls without anterior chest wall protrusion, using a 3-dimensional (3D) computed tomography (CT) to evaluate whether the overgrowth of costal cartilage exists in patients with pectus carinatum. SUBJECTS AND METHODS: Twenty-six patients with symmetric pectus carinatum and matched twenty-six controls without chest wall protrusion were enrolled. We measured the full lengths of the 4th-6th ribs and costal cartilages using 3-D volume rendering CT images and the curved multiplanar reformatted (MPR) techniques. The lengths of ribs and costal cartilages, the summation of rib and costal cartilage lengths, and the costal index [length of cartilage/length of rib * 100 (%)] were compared between the patients group and the control group at 4th-6th levels. RESULTS: The lengths of costal cartilage in patient group were significantly longer than those of control group at 4th, 5th and 6th rib level. The lengths of ribs in patient group were significantly shorter than those of control group at 4th, 5th and 6th rib level. The summations of rib and costal cartilage lengths were not longer in patients group than in control group. The costal indices were significantly larger in patients group than in control groups at 4th, 5th and 6th rib level. CONCLUSION: In patients with symmetric pectus carinatum, the lengths of costal cartilage were longer but the lengths of rib were shorter than those of controls. These findings may supports that the overgrowth of costal cartilage was not the only factor responsible for pectus carinatum.

Regrown first rib in patients with recurrent thoracic outlet syndrome.

BACKGROUND: Recurrent symptoms of thoracic outlet syndrome (TOS) after first rib resection have varying etiologies. Regrowth of a first rib is a rare event. Recurrent symptoms in the presence of a regrown rib strongly suggest a causal relationship. We report our experience with recurrent symptoms of TOS and regrown first ribs. METHODS: We identified patients with recurrent TOS symptoms and regrown first ribs presented between 1995 and 2012. Details regarding their presentation, evaluation, and treatment were gathered. RESULTS: Eight patients (6 women and 2 men) presenting with recurrent TOS symptoms and regrown first ribs underwent 10 decompression surgeries. Prior surgeries included supraclavicular first rib resection (5), transaxillary first rib resection (5), scalenectomy (5), cervical rib resection (1). The average period between initial surgery and reoperation was 4.7 years. Average age at current presentation was 40.8 years (range 29-52). All patients (8) represented with neurogenic symptoms and 1 patient with concomitant venous TOS symptoms. Presenting symptoms included pain (8), numbness and tingling (7), weakness (6), headache (2), and venous congestion (3). Initial treatment included physical therapy in all. Preoperative assessment included chest X-rays (8), magnetic resonance imaging (7), electrodiagnostic studies (8), venography (2), and anterior scalene muscle block (2). Surgical approach included transaxillary resection of the regrown first rib (10), neurolysis of brachial plexus (10), scalenectomy (5), and lysis of subclavian vein (1). After an average follow-up of 10.8 months, resolution of symptoms included 4 complete and 4 partial. CONCLUSIONS: Regrowth of the first rib is a rare event. There is a concordance between a regrown rib and TOS symptoms. Patients presenting with recurrent TOS symptoms and a regrown first rib have a high probability of improvement with resection of the regrown rib.

CT measured normative cartilage growth in children requiring costochondral grafting.

OBJECTIVE: Careful operative timing is required for children undergoing microtia repair using autologous costochondral grafting. This operation is performed as early as age 6 in efforts to treat children before school matriculation while allowing for sufficient rib growth. There remains a paucity of data regarding cartilaginous growth of the ribs and synchondrosis routinely harvested during microtia repair. This study employs CT imaging to generate normative costochondral growth characteristics in children. STUDY DESIGN: A population-based study was performed. SETTING: Tertiary care children's hospital. SUBJECTS AND METHODS: Chest CTs were reviewed in 360 children ages 3 to 20 years. Measurements included: length of ribs 6, 7, and 8 and the height and width of the synchondrosis between ribs 6 and 7. Growth charts are presented for gender and laterality. RESULTS: At age 6: ribs 6, 7, and 8 measure 5.96 ± 0.69, 7.79 ± 0.84, and 6.33 ± 1.01 cm, respectively. In adulthood the mean length of ribs 6, 7, and 8 are 8.29 ± 1.00, 11.10 ± 1.19, and 8.95 ± 1.99 cm, respectively. The vertical height of the synchondrosis at years 6 and 20 are 2.42 ± 0.39 and 3.59 ± 0.53 cm, respectively. Ribs 6, 7, and 8 as well as the synchondrosis grow in a nearly linear fashion. CONCLUSIONS: Cartilaginous growth of ribs 6 to 8 during early childhood is nearly linear. Synchondrosis height approaches adult auricle width at 8 years. Rib size is consistently larger in males and on the left side. These data are useful for the pediatric otolaryngologist and facial plastics and reconstructive surgeon performing microtia surgery.

Differential growth and development of the upper and lower human thorax.

The difficulties in quantifying the 3D form and spatial relationships of the skeletal components of the ribcage present a barrier to studies of the growth of the thoracic skeleton. Thus, most studies to date have relied on traditional measurements such as distances and indices from single or few ribs. It is currently known that adult-like thoracic shape is achieved early, by the end of the second postnatal year, with the circular cross-section of the newborn thorax transforming into the ovoid shape of adults; and that the ribs become inclined such that their anterior borders come to lie inferior to their posterior. Here we present a study that revisits growth changes using geometric morphometrics applied to extensive landmark data taken from the ribcage. We digitized 402 (semi) landmarks on 3D reconstructions to assess growth changes in 27 computed tomography-scanned modern humans representing newborns to adults of both sexes. Our analyses show a curved ontogenetic trajectory, resulting from different ontogenetic growth allometries of upper and lower thoracic units. Adult thoracic morphology is achieved later than predicted, by diverse modifications in different anatomical regions during different ontogenetic stages. Besides a marked increase in antero-posterior dimensions, there is an increase in medio-lateral dimensions of the upper thorax, relative to the lower thorax. This transforms the pyramidal infant thorax into the barrel-shaped one of adults. Rib descent is produced by complex changes in 3D curvature. Developmental differences between upper and lower thoracic regions relate to differential timings and rates of maturation of the respiratory and digestive systems, the spine and the locomotor system. Our findings are relevant to understanding how changes in the relative rates of growth of these systems and structures impacted on the development and evolution of modern human body shape.

Growth-sparing spinal instrumentation in skeletal dysplasia.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To report the outcomes of distraction-based, growth-sparing spinal instrumentation in patients with skeletal dysplasia. SUMMARY OF BACKGROUND DATA: Patients with skeletal dysplasia with spinal deformity often undergo early fusion, further compromising an already small chest. Nonfusion techniques may provide a safe alternative and allow for thoracic growth. METHODS: Between 2004 and 2010, 12 children with a diagnosis of various types of skeletal dysplasia underwent growth-sparing spinal instrumentation for severe spinal deformities. The mean duration of treatment with growing rods was 57 months (42-84 mo). Nine patients were treated with growing rods (8 dual, 1 single), and 3 were treated with vertical expandable prosthetic titanium rib (VEPTR; Synthes). Preoperative, initial postoperative, and final follow-up anteroposterior and lateral spine radiographs were measured for magnitude of deformity, junctional kyphosis, and implant failure. RESULTS: The major curve Cobb angle improved from a mean of 79° preoperatively to a mean of 41° at the last follow-up (52%). There was a decrease in mean thoracic kyphosis from 77° preoperatively to 64° at final follow-up and an increase in mean lumbar lordosis from 58° preoperatively to 63° at final follow-up. The mean space available for the lungs increased by 26 mm on the concave and 24 mm on the convex side. Six patients required revision surgery for proximal junctional kyphosis. There were 4 rod failures and 6 hook and 8 screw dislodgements. One patient with vertical expandable prosthetic titanium rib had failed rib fixation that required revision. CONCLUSION: Growth-sparing spinal instrumentation in patients with skeletal dysplasia and severe spinal deformity has a high complication and revision rate, and surgeons should closely monitor these patients. The complication rate is comparable with previous reports on patients with other diagnoses. However, deformities were well controlled, some trunk growth was achieved, and fusion surgery was delayed in all cases. LEVEL OF EVIDENCE: 4.

Bilateral pre-expanded free TFL flaps for reconstruction of severe thoracic scar contractures in an 8-year-old girl.

We present the case of an 8-year-old girl who suffered from acute myeloid leukaemia-related necrotising fasciitis in her early childhood resulting in severe skin and soft-tissue loss with subsequent circumferential thoracic scar formation. While tissue expander use yielded successful skin replacement for median scar areas, ribs were covered with ultrathin skin envelope at the lateral thoracic wall leading to growth and shoulder abduction impairment. Skin and soft-tissue reconstruction of these extended rib areas was aimed for in a one-step approach. Both lateral thoracic walls were successfully reconstructed with free microsurgical transfer of large pre-expanded tensor fasciae latae flaps, in order to enable future thoracic growth.