Introduction. This study aims to evaluate the effect of using different types of fixator on the quality of callus and complications during distraction osteogenesis in patients with achondroplasia. Materials and Methods. Forty-nine achondroplasia patients with a minimum follow-up of 36 months who underwent limb lengthening between 2005 and 2017 with external fixator only were included. Thirty-three of the patients underwent lengthening using classical Ilizarov frame, while spatial frame used for sixteen. Regenerate quality is evaluated according to the Li classification on the X-ray taken one month after the end of the distraction. Complications were noted in the follow-up period. Results. The mean age at the time of surgery was 8,6 years. The mean external fixation index (EFI) was 34,3 and 30,1 day/cm for spatial frame and Ilizarov frame respectively. Mean follow-up period of 161,62 months and mean fixator period of 257 days. Amount of lengthening was 7,2 cm for Ilizarov frame, and 7,5 cm for spatial frame. Rate of callus with good morphological quality seen at consolidation was 72,4% and 50% for Ilizarov and spatial frames respectively. Two groups show similar results of complication rates in terms of pin site infection, premature fibular consolidation, regenerate fracture, plastic deformation, knee contracture. However fibular nonunion rates were higher for Ilizarov-type fixator. Conclusions. Although spatial frame with computer assistance brings easier follow-up for deformity correction, Ilizarov-type external fixator show slightly higher rates of good quality callus during consolidation for patients with achondroplasia

Although achondroplasia has been cited as the most common form of rhizomelic dwarfism, no report in the literature has given the data on the ratio of their upper and lower limb segments. We performed a paired study of 91achondroplasia patients with age and gender matched normal control group. Their upper and lower extremity radiographs were evaluated, and their radio-humeral and tibia-femoral ratios were compared. The ratios were compared using the Wilcoxon rank sum test. A p value of <0.05 was considered significant. The mean age of the patients was 15.8 years (95% confidence interval (CI), 13.1–18.6), and there were 45 males and 46 females. The radio-humeral ratio for the upper extremity of achondroplasia patients was 0.76 (95% CI, 0.75–0.76) which was significantly different from the normal control group of 0.79 (95% CI, 0.77–0.80) (p=0.001). The tibio-femoral ratio of the achondroplasia patients was 0.79 (95% CI, 0.78–0.79), which was not significantly different from the normal control group of 0.78 (95% CI, 0.77–0.79) (p=0.346). Rhizomelia is the predominant form of dwarfism in upper extremity, but not in lower extremity in achondroplasia. The functional deficits from these patients seem to come from the generalized limb shortness, and not specifically from rhizomelia

Introduction. To evaluate the results of correction of knee deformities based on deformity analysis in Achondroplasia, the commonest skeletal dysplasia as some have concomitant ligamentous deformities. Materials and Methods. Retrospective study from a prospective database (2007–2020) of achondroplasts who underwent growth modulation. Analysis of medical records with objective measurement of mechanical axis radiographs was done (Traumacad). Satisfactory alignment was defined as neutral to slightly varus (0–15 mm MAD) so that the MCL/LCL laxity is not revealed. Results. 23 patients, 41 limbs, 34 bilateral, 6 unilateral underwent multiple growth modulation procedures. 2 had valgus knees. 15 patients underwent proximal fibular epiphysiodesis in addition for LCL laxity with one isolated fibular epiphysiodesis. Mechanical axis deviation (MAD) improved or normalised in 16 patients (70%). 4 patients were still undergoing correction. 4 patients needed further surgery out of which 2 patients were over 13 years when growth modulation was attempted and 2 needed correction of ankle varus. JLCA improved/ normalised in 12 patients (75%) with evidence of indirect LCL tightening and no improvement was seen in 4. The rate of correction was MAD 0.61mm/month, LDFA 0.29°/month and MPTA 0.13°/month; expectedly lower in achondroplasia due to lower growth velocity. Conclusions. This study highlights the pathology, application of growth modulation as per deformity analysis unlike previous studies. Proximal fibular epiphysiodesis improves LCL laxity in a majority of these children and is a simple procedure compared to our published series with indirect LCL tightening with frames

Aim. The aim of the study was to characterise gait in patients with achondroplasia post lengthening. Patients/Materials and Methods. Full kinematic and kinetic lower limb gait analysis was performed at the Sheffield Children's Hospital gait laboratory, Sheffield, using a Vicon system (6 cameras working at 50Hz) and processed using Plug In Gait modelling software. The lengthened Achondroplasia group (n=11, mean age = 24.5 ± 6.1) had previously undergone surgical lengthening of the legs. The lengthened Achondroplasia group was compared to a control group of 11 adult normal subjects. Results. Averaged sagittal plane kinematics are shown in Figure 1. The key sagittal plane characteristics we found were increased anterior pelvic tilt (Achondroplasia mean = 22.2 ± 7.1°, normal mean = 14.2 ± 5.3°), decreased peak hip extension (Achondroplasia = 10.5 ± 11.2°, normal = −5.8 ± 5.3°), increased peak hip flexion (Achondroplasia = 49.3 ± 9.8°, normal = 40.0 ± 5.2°), and reduced knee extension in midstance (Achondroplasia = 14.0 ± 8.5°, normal = 4.4 ± 8.5°) At the ankle the mean of the lengthened Achondroplasia group lies within one standard deviation of the normal dataset throughout the gait cycle. Summary and Conclusions. Three dimensional gait analysis of people with Achondroplasia following lower limb-lengthening surgery showed characteristic Achondroplasic gait, that is: increased anterior pelvic tilt, reduced hip extension and increased hip flexion. The group of lengthened Achondroplasia participants also failed to extend the knees fully in midstance. At the ankle the sagittal plane kinematics were within one standard deviation of the normal dataset

Introduction We have reviewed the clinical outcome and complications of Monofocal and Bifocal Callotasis for lower limb lengthening in children with Achondroplasia. Methods Between August 1986 and January 1999, 57 children with Achondroplasia had lower limb lengthening. Monofocal callotasis had been carried out in 147 Segments of 44 children and bifocal callotasis in 38 segments of 17 children. Complications were noted and final outcomes recorded. Results The 29 children who completed the programme gained an average of 20 cms in height. For all patients, the mean length gained per segment was roughly nine centimetres. Average Bone Healing Index in the mono-focal lengthening group was 39.9 days/cm and in the bifocal lengthening group 33.6 days/cm. Complications were staged and graded and the average was 2.8 complications per lengthened segment. Most were pin-site related and occurred during stage of distraction. Twenty percent of the segments required further axis corrections. Most patients regained their pre-operative range of motion. Serious irreversible complications were seen in only two patients and included a physeal bar and psychological disturbances. Functional outcome analyses are planned. Conclusions Limb lengthening for short stature due to Achondroplasia can be confidently undertaken with favourable results in most cases. Bifocal lengthening is an alternative technique with quicker consolidation time

Introduction: Achondroplasia is a form of rhizomelic dwarfism. Even if patients can compensate for their short arms through the mobility in their spine during the childhood, the flexibility in their spine becomes less with aging. Because of that, as they get older they experience problems in maintaining personal hygiene especially in reaching the back. In addition putting on socks and tying their own shoes might become difficult. Methods: Inclusion criteria included any patient with a history of achondroplasia who had undergone humeral lengthening in the proximal part of the humerus (just distal to deltoid muscle insertion). Patients who had distal humeral (supracondylar) osteotomy and/or who received other than monolateral external fixator were excluded from the study. 50 humeri of 25 patients with achondroplasia were lengthened using Orthofix mono-lateral external fixator utilizing proximal humeral osteotomy. Sixteen patients were female and nine were male. Mean age was 15.4 months (range, 9.6 – 21.8). Lengthening was started at 7th day. Patients were lengthened at 1/4 turn four times a day reaching 1 mm/day. Physical therapy was performed 3 times a week. Goal of lengthening was around 10 cm or whatever length the patient could tolerate. Patients wore Sarmiento type fracture brace 4–6 weeks after the fixator was removed. Results: Mean follow-up time from surgery was 51.5 months (range, 6 – 143 months). Mean follow-up time from removal of external fixator was 44.7 months (range, 0 – 135 months). Average external fixation time was 7.3 months. In 20 humeri it was noted that the average duration of lengthening was 4.2 months (range, 3 – 5.8 months). A mean lengthening of 9.3 cm was obtained (range, 4.3 – 12.8 cm). At latest follow-up range of motion was not compromised due to lengthening. All patients had similar ROM before and after the surgery. Complications included radial nerve palsy in 8, pin tract infection in 7, fracture through regenerate in 3, premature consolidation in 1, nonunion in 1, delayed healing in 1. Radial nerve palsy recovered without intervention in one case. In others it recovered uneventfully after successful decompression. No complications at all occurred in 30 cases. Discussion: Fifty humeri of 25 patients with achondroplasia received successful humerus lengthening as part of extensive limb lengthening offered in our center. None of the patients had long term sequela, and all radial nerve palsies recovered. Patients were satisfied with the lengthening and found it easier to undergo through humerus lengthening compared to lower limb lengthening. After a mean follow-up time of almost 4 years, these patients returned back to their normal lives with optimum upper limb function with no hindrance in maintaining personal hygiene, putting on socks or tying their own shoes

Background: The incidence of neurological symptoms due to spinal stenosis in patients with achondroplasia is reported to be as great as 38%. 1. These symptoms most commonly occur in the 4. th. decade and myelography and CT myelography are most commonly described in evaluation of the stenosis. Difficulty arises in localisation of stenosis in patients presenting with neurological deficit. 2. The value of MRI of the cervicomedullary junction has been reported in achondroplasia but it has not yet been evaluated in the investigation of spinal stenotic symptoms. The aim of this study was to review our experience of whole spine imaging in patients with achondroplasia that presented with symptoms and signs of neurological deficit. Methods: We retrospectively reviewed the clinical notes and radiological imaging of 10 consecutive achondroplastic patients (3F:7M, mean age 31.7 years, range 13 to 60yrs) that presented to our unit with neurological compromise between 1998 and 2003. All patients had whole spine MRI at the time of presentation. Recorded from the notes were age and sex, and whether symptom pattern was radiculopathy, claudication or paresis. All radiological levels of stenosis on MRI were documented. Results: Four patients presented with spinal paresis, four with neurogenic claudication, and two with radiculopathy. MRI confirmed that each patient had at least one region (cervical, thoracic or lumbar) of significant spinal stenosis. In six of the patients an additional region of significant stenosis was identified. All ten patients had lumbar stenosis but this was only the primary site in six of the ten. In the other four patients two had the dominant stenosis in the thoracic spine, one in the cervical spine and one at the foramen magnum – the clinical symptoms correlated with the dominant site in each of these four cases. Conclusion: MRI was a useful tool for assessment of neurological compromise in the patients with achondroplasia in our study. All ten patients had classical lumbar stenosis on MRI but this was only the dominant site of stenosis in six of the ten cases. The MRI and clinical findings need to be evaluated together to ensure correct surgical treatment

Aim: Spinal stenosis is a known entity in achondroplasia and a need for screening for the symptomatic children was identified in a tertiary limb reconstruction service. The aim of this study was to evaluate whether clinical and radiological imaging would identify the at risk group. Materials and methods: 205 achondroplastic children were treated at our service in the last 20 years. A prospective clinical screening programme for spinal stenosis which also included the MRI imaging of entire spine was however introduced only in 1996. 26 patients were available for this study. Case notes were reviewed for clinical symptoms and neurological signs. MR images were assessed for stenosis especially at Cervico medullary junction and lumbar level. Canal diameters were measured at all spinal levels from CMJ to lumbo-sacral junction. Neurosurgical interventions were recorded. An attempt was made to identify high risk factors that required surgical intervention. Results: Delayed milestones were observed in 7 patients. Positive history of back pain or radicular pain was obtained in 10 whereas 10 patients had symptoms of neurogenic claudication. Brisk reflexes and clonus were consistent findings. Severe foramen magnum narrowing was observed in 23 patients and 13 showed ‘kinking’ or ‘pinching’, suggesting severe compression. Of the 17 patients seen by neurosurgeons 6 required single or multiple surgical decompressions. Ventriculo-peritoneal shunt was inserted in 4. 5 children required CMJ decompression and one required lumbar canal decompression. There was a 7 mm difference in AP diameter measured on MRI at CMJ between the two non operated and operated groups. Female patients with delayed milestones and CMJ narrowing to less than 25 mm were identified as high risk. Conclusion: The cause of increased morbidity and mortality in young achondroplasts is attributable to severe CM compression. Sudden death can occur by acute or gradual progressive encroachment of respiratory centre at medulla oblongata. We were able to identify symptomatic patients early before developing myelomalacia and cord changes by screening all symptomatic children with achondroplasia. We propose that female gender, especially with delayed milestones as another high risk factor. We stress upon the importance of developing a nationalised selective screening programme with guidelines in specialist orthopaedic and joint multi-disciplinary Skeletal Dysplasia clinics

Our aim is to evaluate life quality in patients with achondroplasia after lengthening. We examined 17 patients (11 men and 6 women) who finished the complete lengthening process in the 3 segments (tibia, femur, humerus) more than 3 years ago. Mean age 30.35 years(17–44). And a final height of 152.3cm (140.4–169) with an increase in the size of the tibia of 15.38cm, femur 14.91cm and humerus 9.91cm. Life quality is assessed by the SF.36 test and a specific questionnaire for low size people. The results show that the mental health component (52.2) and physical component (52.8) are similar to those of general American population. There is also a statistical correlation between the final height and better results on the Mental Health questions of SF.36 (p=0.013) and the psychological questions of the specific questionnaire (p=0.045). Achondroplasic patients after lengthening have a standard life quality and the increase of their height improves the mental health aspects of life quality

Introduction

The effect of lower extremity lengthening on physeal growth is still controversial. We aim to compare data of the patients who had bilateral simultaneous femur and tibia lengthening with the patients who underwent the lengthening surgery separately for the femur and tibia at the end of completed skeletal maturation in terms of the effect of physeal growth.

Introduction Sequestered disc fragments in the achondroplastic dwarf are rare. They should be removed by an anterior approach because:

access to remove the fragment posteriorly is severely compromised by the condition.

Method The case is of a 30 year old achondroplastic dwarf with spontaneous sudden onset of myelopathy over three myotomes. An MRI scan revealed an L1-2 large disc herniation compressing the thecal sac in an already small canal.

Results The spinal decompression resulted in recovery from the paresis without creating the instability associated with a wide posterior exposure.

Discussion The thoraco-abdominal approach involves incision along the line of the rib two levels above the most proximal vertebral body to be visualized. The external oblique and internal oblique are incised in the line of the rib. The diaphragm is taken down from the costal cartilage to the crus posteriorly allowing access to the upper lumbar spine. The segmental vessels are identified and subperiosteal dissection carried out. The disc is excised and the adjacent posterolateral vertebral body extending toward the segmental vessels. The neural elements are decompressed and the spine is stabilized using the rib strut as graft in the space created by the vertebral resection with morselized graft into the intervertebral disc space.

Introduction: Plastic deformation of the regenerate bone is a complication noted soon after limb lengthening. However, less is known about the factors responsible for the development of plastic deformation.

Materials and Methods: Retrospective analysis of 35 X-rays of achondroplast children who had limb lengthening were reviewed. The study compared Monofocal Vs Bifocal and Long lengthenings(> 10 cms) Vs modest lengthenings(≤ 10 cms) of tibial lengthening. Other parameters included in study were Bone healing Index, total length gained and sagittal and coronal axial deformities. There were 20 females and 15 males, 21 long lengthenings and 14 modest lengthenings in the study. The joint orientation and diaphyseal angles(antero-posterior and lateral X-ray views) was used for the measurement of plastic deformation of the regenerate bone.

Results: The mean age at operation was 10 years (range; 6–16 years). There were 29 cases of monolateral fixator and 6 of Ilizarov ring fixator, Of which 26 had monofocal lengthening and 9 had bifocal lengthening (34 callotasis and 1 chondrodiastasis). The total average length gained was 10 cms (range; 23–152). The mean bone healing index and external fixation index/time were 41 days and 352 days respectively. Plastic deformation of the regenerate bone was seen in 26 cases in total. 24 out of 29 cases of monolateral fixator (82%) developed plastic deformation. 44%(4/9) of bifocal group and 84%(22/26) of monofocal group showed evidence of plastic deformation. The long lengthenings showed plastic deformation in 85% (18/21) of the cases, whereas only 57%(8/14) of the cases were positive in modest lengthening group. Most of the axial deviation was in the coronal plane in 92% (24/26) and the sagittal plane accounted to only 23%(6/26) requiring surgical correction.

Conclusions: Long lengthenings and monofocal techniques showed more plastic deformation than bifocal and short lengthenings. However, Ilizarov ring fixator with bifocal corticotomy seemed to be promising with less association with the above entity in our recent experience.

Abstract. Introduction. Total knee replacement (TKR) in patients with skeletal dysplasia is technically challenging surgery due to deformity, joint contracture, and associated co-morbidities. The aim of this study is to follow up patients with skeletal dysplasia following a TKR. Methodology. We retrospectively reviewed 22 patients with skeletal dysplasia who underwent 31 TKRs at our institution between 2006 and 2022. Clinical notes, operative records and radiographic data were reviewed. Results. Achondroplasia was the most common skeletal dysplasia (8), followed by Chondrodysplasia punctata (7) and Spondyloepiphyseal dysplasia (5). There were fourteen men and eight women with mean age of 51 years (28 to 73). The average height of patients was 1.4 metres (1.16–1.75) and the mean weight was 64.8 Kg (34.3–100). The mean follow up duration was 68.32 months (1–161). Three patients died during follow up. Custom implants were required in twelve patients (38.71%). Custom jigs were utilised in six patients and two patients underwent robotic assisted surgery. Hinged TKR was used in seventeen patients (54.84%), posterior stabilised TKR in nine patients (29.03%), and cruciate retaining TKR in five patients (16.13%). One patient underwent a patella resurfacing for persistent anterior knee pain and another had an intra-operative medial tibial plateau fracture which was managed with fixation. No revisions occurred during the follow up period. Conclusion. Despite the technical challenges and complexity of TKR within this unique patient group, we demonstrate good implant survivorship during the study period. Cross sectional imaging is recommended preoperatively for precise planning and templating

Genetic skeletal disorders constitute a rare and heterogeneous bone diseases often leading to poor quality of life. Several surgical options are available. The surgeon must deal with specific features (bone deformity, previous procedures, abnormal bone quality, stiffness or instability, muscle weakness). The questions concern the feasibility of the procedures and the surgical strategy. 55 patients (26 W, 29 M) were reviewed between 2016 and 2022. The mean age of the patients was 35 years (17–71). The diagnosis included 9 hereditary multiple exostoses, 8 osteogenesis imperfecta, 6 multiple epiphyseal dysplasia congenita, 6 achondroplasia, 4 osteopetrosis, 3 pycnodysostosis, 3 hypophosphatemic rickets, 3 fibrous dysplasia, 2 mucopolysaccharidosis, and 10 miscellaneous. 25 patients were referred for hip problems (40 hips). 4 patients (7 hips) requiring a THA have not been operated (4 planned). 4 patients (6 hips) had a proximal femoral fixation (2 osteotomies, 4 fracture fixations). 17 patients (27 hips) sustained a THA (25 primary, 2 revisions). All of them were operated by one operator, using a posterolateral approach and standard implants (including 7 dysplastic and 2 short stems). No customized implant has been used. As regard the 27 THAs, the mean follow up was 4.2 years (1–12). The early complications included 2 femoral cracks and 1 femur fracture. There were 2 revisions (1 cup loosening at 2 years, 1 stem loosening at 4 years). No infection nor dislocation occurred. All the patients were satisfied with their treatment and regain some autonomy. 3 THA were considered as unfeasible. Constitutional bone diseases need a multidisciplinary program of care. The indication for surgery is based on a mutual trust patient/surgeon, a careful evaluation of benefits/risks, and an accurate imaging to anticipate the difficulties. The expected results are a better function and quality of life, and a stability over time

Introduction. Angular deformity in the lower extremities can result in pain, gait disturbance, deformity and joint degeneration. Guided growth modulation uses the tension band principle with the goal of treatment being to normalise the mechanical axis. To assess the success of this procedure we reviewed our results in an attempt to identify patients who may not benefit from this simple and elegant procedure. Materials and Methods. We reviewed the surgical records and imaging in our tertiary children's hospital to identify all patients who had guided growth surgery since 2007. We noted the patient demographics, diagnosis, peri-operative experience and outcome. All patients were followed until skeletal maturity or until metalwork was removed. Results. 173 patients with 192 legs were assessed for eligibility. Six were excluded due to inadequate follow-up or loss of records. Of the 186 treated legs meeting criteria for final assessment 19.8% were unsuccessful, the other 80.2% were deemed successful at final follow up. Complications included infection and metal-work failure. Those with a pre-treatment diagnosis of idiopathic genu valgum/ varum had a success rate of 83.6%. Conclusions. In our hands, guided growth had an 80-percent success rate when all diagnosis were considered. Those procedures that were unlikely to be successful included growth disturbances due to mucopolysaccharide storage disease, Blounts disease and achondroplasia. Excluding those three diagnoses, success rate was 85.4%. We continue to advocate the use of guided growth as a successful treatment option for skeletally immature patients with limb deformity

Introduction and Objective. Virtual Surgical Planning (VSP) is becoming an increasingly important means of improving skills acquisition, optimizing clinical outcomes, and promoting patient safety in orthopedics and traumatology. Pediatric Orthopedics (PO) often deals with the surgical treatment of congenital or acquired limbs and spine deformities during infancy. The objective is to restore function, improve aesthetics, and ensure proper residual growth of limbs and spine, using osteotomies, bone grafts, age-specific or custom-made hardware and implants. Materials and Methods. Three-dimensional (3D) digital models were generated from Computed Tomography (CT) scans, using free open-source software, and the surgery was planned and simulated starting from the 3D digital model. 3D printed sterilizable models were fabricated using a low-cost 3D printer, and animations of the operation were generated with the aim to accurately explain the operation to parents. All procedures were successfully planned using our VSP method and the 3D printed models were used during the operation, improving the understanding of the severely abnormal bony anatomy. Results. The surgery was precisely reproduced according to VSP and the deformities were successfully corrected in eight cases (3 genu varum in Blount disease, 2 coxa vara in pseudo achondroplasia, 1 SCFE, 1 missed Monteggia lesion and 1 post-traumatic forearm malunion deformity). In one case, a focal fibrocartilaginous dysplasia, the intraoperative intentional undersizing of the bone osteotomy produced an incomplete correction of a congenital forearm deformity. Conclusions. Our study describes the application of a safe, effective, user-friendly, VSP process in PO surgery. We are convinced that our study will stimulate the widespread adoption of this technological innovation in routine clinical practice for the treatment of rare congenital and post-traumatic limb deformities during childhood

Twenty-five years ago, Prof. Peter H. Beighton, our association’s geneticist, presented a paper reminding us that more than 2 000 genetic diseases and disorders have been identified. Many of the conditions are apparently confined to one particular geographical locality or ethnic group. A large proportion of genetic diseases and disorders has skeletal manifestations. The Little People of South Africa (Association of Persons with Restricted Growth) have needed advice about the management of orthopaedic complications such as spinal problems in achondroplasia, axial deviations of the lower limbs, and in particular the possibilities of limb lengthening in disproportionate skeletal dysplasias. From the story of a young achondroplastic woman who suffered from low back pain and was offered an operation by a neurosurgeon, there stemmed a media-driven report on dwarfs in the Land of Legends near Tzaneen, an epidemiological field study on achondroplasia in the Northern Province, and a combined round table consultation between a team of orthopaedic surgeons and a pair of Pedi sangomas. In the village was an index group of three Pedi women and one man who were diagnosed with probable acrome-somelic dysplasia (Grebe), a form of achondrogenesis. The oldest woman and the man were brother and sister, and the two younger women their daughters by spouses of normal stature. While their heads and faces were normal and their spines straight, their dysmorphic features included shortness of stature (mean height 94 cm), disproportionate limb length and ligamentous laxity. The little man’s late father was also a dwarf, as was one of his eight brothers: there were thus six dwarfs in a direct line in three generations. The dwarf man and woman were both sangomas, as their father had been. None of them had low back pain, but they knew how to cure it

Introduction: Fibroblast growth factor receptor 3 (FGFR3) is a tyrosine kinase membrane-spanning protein whose function is to regulate chondrocyte proliferation, differentiation and matrix production during cartilage development. Several mutations in FGFR3 have now been documented to link to human diseases. A number of these mutations result in constitutive activation of the FGFR3, leading to proliferation and premature differentiation of chondrocytes. Depending on the mutation and the resultant level of FGFR3 activation, mild to severe skeletal dysplasias such as achondroplasia (ACH), hypochondroplasia (HCH), thanatophoric dysplasia type I (TDI) and type II (TDII), and severe achondroplasia with developmental delay and acanthosis nigrans (SADDAN) may result. It has been postulated that the signalling pathways downstream of FGFR3 may be responsible for activating transcription factors, leading to up-regulation of cell cycle inhibitors and causing abnormal suppression of chondrocyte cell proliferation. However, the precise signalling pathways involved in FGFR3 mutation have as yet to be elucidated. The aim of this study was to investigate and compare the differences in the downstream signalling pathways between FGFR3 mutants. Methods and Results: Wild type FGFR3 has been cloned into expression vector pcDNA3 and the construct has been used to generate four different FGFR3 mutants using site-directed mutagenesis. The mutations which have been introduced and the types of dysplasia they correspond to were as follows: K380R (ACH), N540K (HCH) and K650E (TDII). A kinase dead form of the receptor, K504R has also been generated. Wild type and each of the four mutant FGFR3 proteins in pcDNA3 vector have been successfully transfected into 293T cells using the calcium phosphate method. Immunoprecipitation and Western Blot analysis of cell lysates revealed expression of wild type protein in three isoforms of size 135kDa (mature), 120kDa (intermediate) and 98kDa (immature). The mutant proteins all followed a similar pattern of expression with the exception of the TDII mutant that did not express the mature form of the FGFR3. Changes in MAPK, PLCã and STAT 1 signalling pathways in response to FGFs-1, 2, 9 and 18 in the 293-cells of wild type and mutant forms of FGFR3 are now under investigation, in an attempt to define which pathways are mostly responsible for the resultant abnormal phenotypes. Discussion: Genomics studies have demonstrated that FGFR3 expression is significantly upregulated during the osteoblastic differentiation of mesenchymal stem cells (MSCs) under BMP-2 stimulation in vitro. Subsequent functional studies have demonstrated that a selective ligand for FGFR3, FGF9, is able to induce tyrosine kinase signalling, and the osteoblastic differentiation of MSCs in vitro. Further understanding the signalling mechanisms of FGFR3 activation in normal and mutant forms may lead to discover potential anabolic agents that are based on FGFR3-FGFs pathways

Introduction. Distraction histogenesis is utilised for cosmetic reasons in patients with constitutional short stature, achondroplasias, or height dysphoria. One of the considerations of patients and surgeons alike, is the preservation of aesthetically acceptable body proportions after the lengthening i.e which segment of the lower limb to lengthen and by how much, in order to preserve the patient's proportions within -or as close as possible to- the normal range of human body proportions. Sound anthropometric data on the normal range of the human body proportions is currently lacking. The aim of this study is to calculate the normal range of the ratio between the lengths of the lower limb, upper limb, femur, tibia, stature and trunk. Methods. Data form standardized measurements of the lengths of the tibia, femur, arm, stature, lower limb, upper limb was obtained from a sample population of 6068 healthy men and women servicing in the US Army. The mean, median, range and standard deviation were calculated for the following ratios of lengths: whole lower limb/leg, Stature/leg, Whole lower limb/thigh, Stature/thigh, Siting height/whole lower limb, Stature/Whole lower limb, Arm Span/Stature, Whole upper limb/Whole lower limb. Results. The ratios show normal distribution. Results are presented separately for men and women for the total sample population and for subgroups based on ethnic origin (White, Black, Hispanic and Asian). Discussion. This study is one of the first to provide specific anthropometric data from a large sample population relevant to the evidence-based preoperative planning and patient counselling before cosmetic limb lengthening procedures

Purpose. Angular deformity in the lower extremities can result in pain, gait disturbance, cosmetic deformity and joint degeneration. Up until the introduction of guided growth in 2007, which has since become the gold standard, treatment for correcting angular deformities in skeletally immature patients had been either an osteotomy, a hemiepiphysiodesis, or the use of staples. Methods. We reviewed the surgical records and diagnostic imaging in our childrens hospital to identify all patients who had guided growth surgery since 2007. All patients were followed until skeletal maturity or until their metalwork was removed. Results. 113 patients, with 147 legs were assessed for eligibility. Three were excluded for various reasons including inadequate follow-up or loss of records. Of the 144 treated legs which met the criteria for final assessment 32 (22.2%) were unsuccessful, the other 112 (77.8%) were deemed successful at final follow up. Complications were few, but included infection in one case and metal failure in another. Those with a pre-treatment diagnosis of idiopathic genu valgum/genu varum had a success rate of 83.6%. Conclusions. In our hands, guided growth had a seventy-eight percent success rate when all diagnosis were considered. Those procedures that were unlikely to be successful included growth disturbances due to mucopolysaccharide storage disease (28% failure rate), Blounts disease (66.6% failure rate) and achondroplasia (37.5% failure rate). If you exclude those three diagnoses, success rate for all other conditions was 81.4%. We continue to advocate the use of guided growth as a successful treatment option for skeletally immature patients with limb deformity