Background:Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center.Materials and Methods:Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index.Results:Nine patients aged five to 25 years (mean age 10.2 years) underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%), 9.9 cm (52.8%) and 9.6 cm (77.9%), respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3rd percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment). Healing index was not affected by age or bone segment.Conclusion:Extensive limb lengthening (more than 50% over initial length) carries significant risk and should be undertaken only after due consideration.
Purpose Pamidronate, used for the treatment of paediatric osteoporosis, reduces the fracture rate and improves ambulatory status. Intravenous pamidronate therapy has known complications which have not been stratified based on its dose and distribution. This study aims to assess the early minor and major medical and late surgical complications and the effect of the dose and regimen of infusion on these events in paediatric osteoporosis. Study design Retrospective cohort. Materials and methods Three regimens for pamidronate infusion were followed in sequential periods in 10 years. Regimen A delivered 1.5 mg/kg/day as a single dose once in 3 months. Regimen B delivered 2 mg/kg/day for 3 days twice a year, while regimen C delivered 1 mg/kg/day for 3 days every 3-4 months. Adverse events were classified as early (major and minor) or late (surgical). Results Forty-eight children received 158 infusions using one of the three regimens. Twenty-nine complications occurred in 24 children. A significant difference in the complication rate was present among the three regimens (P = 0.005). Nineteen children had minor complications, mainly febrile reaction or asymptomatic hypocalcaemia. Four major complications consisting of one seizure, one respiratory distress and two hypocalcaemic tetany were encountered, all with regimen B. Intraoperative complication faced was loss of position due to splintering of the cortex while rush rodding. This was seen in 20% of the long bone segments operated in those who received pamidronate as compared to 4.4% of the segments which were operated prior to the initiation of pamidronate therapy; the odds of splintering were 5.4 times higher for those patients who were bone segment rodded after pamidronate therapy. Discussion Intravenous pamidronate is associated with complications in 50% of children with paediatric osteoporosis, with a dose-dependent significant difference. Major complications are not uncommon with higher doses and can be avoided by increasing the number of doses per year and decreasing the dose per cycle. Surgical difficulty, when possible, can be avoided by correcting any major deformities at presentation prior to the induction of pamidronate therapy.
Cryopreservation preserves cells at low temperature and creates a reserve for future use while executing the clinical translation. Unlike articular chondrocyte, cryopreservation protocol and its outcome are not described in iliac apophyseal chondrocytes, a potential source of chondrocytes in cartilage engineering. This study for the first time describes the cryopreservation of human iliac apophyseal chondrocytes. Four cartilage samples were procured from iliac crests of children undergoing hip surgery after consent. The total chondrocyte yield was divided into two groups. First group was grown as monolayer while second group was cryopreserved following the slow cooling method in the medium containing 10 % Dimethyl sulfoxide for 3 months. Group two cells were also grown as a monolayer following thawing. Viability, time to confluence, population doubling time and phenotype maintenance were compared for both the groups. Viability was 65.75 % after 3 months of cryopreservation at -196 °C, as compared to 94.19 % for fresh chondrocytes (p = 0.001). Fresh and cryopreserved cells reached confluence on 10th and 15th day of culture respectively. Population doubling time was significantly more in fresh than cryopreserved chondrocytes on 10th (p = 0.0006) and 15th day (p = 0.0002) in culture. Both fresh and cryopreserved cells maintain their chondrocyte phenotype as assessed by immunocytochemistry. Relative gene expression by real time polymerase chain reaction showed similar upregulation of mRNA of Collagen 2, SOX 9, Aggrecan and Collagen 1 in cryopreserved chondrocyte as compared to fresh chondrocyte. Iliac apophyseal chondrocytes cryopreserved for 3 months maintained the phenotype successfully 2 weeks after thawing in culture. The viability and proliferation rates after thawing were adequate for a clinical translation of these cells.
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