Dynamic Distraction External Fixation for Contracture of the Metacarpophalangeal Joint.

Metacarpophalangeal (MP) joint contractures are common after traumatic injury, and can be difficult to manage. After surgical capsulectomy, it remains challenging to maintain motion that was obtained at the time of surgery. Our group uses a novel, prefabricated digital external fixator to provide both distraction, and motion therapy across the MP joint after surgical treatment of MP contracture. The purpose of this technique is to demonstrate the effectiveness of an adjunctive dynamic distraction external fixator for the maintenance of joint motion after surgical treatment of MP contractures of the border digits.

Escoliosis de aparición precoz. ¿Qué opciones tengo? / Early onset scoliosis. What are the options?

El pronóstico de los ni˜nos con escoliosis de aparición precoz progresiva ha mejorado considerablemente gracias a los recientes avances en las técnicas quirúrgicas y no quirúrgicas, y al reconocimiento de la trascendencia de preservar la cavidad torácica. La mejora de técnicas ya existentes y el desarrollo de otras nuevas han modificado sustancialmente el tratamiento de esta entidad. Los yesos derrotatorios pueden indicarse en ni˜nos con curvas < 60◦ y progresión constatada, a los que no se ha realizado tratamiento quirúrgico previo. Tanto los tallos de crecimiento únicos como dobles son eficaces, aunque los últimos parecen ofrecer un mejor resultado. Los sistemas híbridos se plantean como mejor opción en ni˜nos que requieren un anclaje proximal con un perfil bajo. El vertical expandable prosthetic titanium rib (VEPTR®) puede ser útil en pacientes que presentan escoliosis congénita con fusiones costales y síndrome de insuficiencia torácica asociado. Los ni˜nos no tributarios de elongaciones repetidas por sus comorbilidades pueden ser candidatos a una técnica de Shilla o trolley de Luque. La modulación del crecimiento utilizando grapas de memoria o tirantes resulta prometedora en curvas menores, aunque se requieren más trabajos para definir su indicación precisa (AU)

The prognosis of children with progressive early onset scoliosis has improved considerably due to recent advances in surgical and non-surgical techniques and the understanding of the importance of preserving the thoracic space. Improvements in existing techniques and development of new methods have considerably improved the management of this condition. Derotational casting can be considered in children with documented progression of a < 60◦ curve without previous surgical treatment. Both single and dual growing rods are effective, but the latter seem to offer better results. Hybrid constructs may be a better option in children who require a low-profile proximal anchor. The vertical expandable prosthetic titanium rib (VEPTR®) appears to be beneficial for patients with congenital scoliosis and fused ribs, and thoracic Insufficiency Syndrome. Children with medical comorbidities who may not tolerate repeated lengthenings should be considered for Shilla or Luque Trolley technique. Growth modulation using shape memory alloy staples or other tethers seem promising for mild curves, although more research is required to define their precise indications (AU)

Role of hybrid monolateral fixators in managing humeral length and deformity correction.

BACKGROUND AND PURPOSE: Humeral lengthening and deformity correction are now being done increasingly for various etiologies. Monolateral external fixators have advantages over traditional Ilizarov circular fixators; they are easy to apply, they are less bulky, and they are therefore more convenient for the patient. We assessed the effectiveness of hybrid monolateral lateral fixators in humeral lengthening and deformity correction. METHODS: We retrospectively reviewed 23 patients (40 humeri) with various pathologies who underwent lengthening-with or without deformity correction using monolateral external fixator-between 2003 and 2008. Mean age at the time of the surgery was 14 (10-22) years. The mean follow-up time was 3.4 (1-7) years. RESULTS: The average duration of external fixator use was 8.3 (6-19) months. The mean lengthening achieved was 8.8 (4-11) cm and percentage lengthening was 49% (19-73). The healing index was 28 (13-60) days/cm. The major complications were refracture in 3 humeri and varus angulation of 2 humeri. The minor complications were superficial pin tract infection (6 segments), transient radial nerve palsy (1 segment), and elbow flexion contracture (5 segments). All complications resolved. INTERPRETATION: Hybrid monolateral fixators can be used for humeral lengthening and deformity correction. The advantage over circular fixators is that they are less bulky and patients can perform their day-to-day activities with the fixator in situ.

Comparison between upper and lower limb lengthening in patients with achondroplasia: a retrospective study.

Lengthening of the humerus is now an established technique. We compared the complications of humeral lengthening with those of femoral lengthening and investigated whether or not the callus formation in the humerus proceeds at a higher rate than that in the femur. A total of 24 humeral and 24 femoral lengthenings were performed on 12 patients with achondroplasia. We measured the pixel value ratio (PVR) of the lengthened area on radiographs and each radiograph was analysed for the shape, type and density of the callus. The quality of life (QOL) of the patients after humeral lengthening was compared with that prior to surgery. The complication rate per segment of humerus and femur was 0.87% and 1.37%, respectively. In the humerus the PVR was significantly higher than that of the femur. Lower limbs were associated with an increased incidence of concave, lateral and central callus shapes. Humeral lengthening had a lower complication rate than lower-limb lengthening, and QOL increased significantly after humeral lengthening. Callus formation in the humerus during the distraction period proceeded at a significantly higher rate than that in the femur. These findings indicate that humeral lengthening has an important role in the management of patients with achondroplasia.

Redução de defeito ósseo maxilar por meio de distração osteogênica horizontal / Reduction of maxillary bone defect by horizontal distraction osteogenesis

A reabilitação de maxilas edêntulas em muitas situações pode se tornar um desafio para os implantodontistas. Em um grande numero de casos a instalação de implantes só pode ser realizada após o procedimento de enxertia óssea. No entanto existem casos em que o defeito ósseo atinge níveis tão severos que não permite a instalação de implantes mesmo após procedimentos de enxertia. No presente trabalho, relatamos um caso clinico onde o paciente apresentava um grande defeito ósseo na região posterior da maxila causado por projétil de arma de fogo. Devido a inviabilidade de se realizar um procedimento de enxertia convencional, foi optado por realizar a distração osteogênica horizontal. Após o período de ativação e de consolidação o aparato foi removido e foi instalada uma placa para garantir a estabilidade do local. O procedimento se mostrou de fácil realização e o resultado obtido foi a quase que completa eliminação do defeito ósseo

The rehabilitation of edentulous jaws in many situations can become a challenge for implantodontists. In a large number of cases the installation of implants can only be performed after the bone grafting procedure. However there are cases where the bone defect so severe that reaches levels not allow the installation of implants even after grafting procedures. In this paper, we report a clinical case where the patient had a large bony defect in the posterior region of the maxilla caused by a projectile from a firearm. Because of the impracticality of conducting a conventional grafting procedure was chosen to perform the horizontal distraction osteogenesis. After the activation period of consolidation and the apparatus was removed and a plate was installed to ensure the stability of the site. The procedure proved easy to perform and the result was the almost complete elimination of the bone defect

Secuencia de Pierre Robin / Pierre Robin Sequence

La secuencia de Pierre Robin es una tríada compuesta por retromicrognatia, glosoptosis y fisura palatina, con una prevalencia de 1:8500. El 40 a 50% son casos aislados, el resto forma parte de patrones malformativos complejos. Nuestro objetivo fue valorar la frecuencia de la secuencia de Pierre Robin como entidad aislada o formando parte de asociaciones malformativas y proponer para ambos grupos un esquema de diagnóstico y de recursos terapéuticos. Se realizó un estudio retrospectivo, descriptivo, de 83 pacientes portadores de secuencia de Pierre Robin de la Sala de Genética del Hospital de Niños "Sup. Sor María Ludovica" de La Plata, entre 1993 y 2009. El 45% (n=37) fueron formas aisladas y el 55% (n=46) formas sindrómicas. En este último grupo, las entidades génicas se observaron en 31 niños, siendo el síndrome de Stickler (n=18) y el síndrome de Treacher Collins (n=5) los más frecuentes. El síndrome de Di George (CATCH 22) (n=7) predominó entre las anomalías cromosómicas (n=11) y el misoprostol relacionado con el síndrme de Moebius (n=4) fue el teratógeno predominante. A 9 pacientes del total se les realizó distracción osteogénica (6 pacientes con secuencias de Pierre Robin aisladas y 3 con secuencias de Pierre Robin sindrómica), 2 pacientes de cada grupo fueron traqueostomizados previamente a la distracción. Se utilizaron distractores extraorales de titanio e intraorales de material reabsorbible, lográndose una elongación mandibular entre 15 y 20 mm, en un promedio de 21 días, que permitió evolutivamente la descanulación en tres de los cuatro pacientes traqueostomizados. Concluimos que nuestros datos se correlacionan con los informes bibliográficos. Ante un niño con secuencia de Pierre Robin, sugerimos a los neonatólogos y pediatras realizar un minucioso examen físico para detectar dismorfias y solicitar estudios complementarios orientadores de alguna entidad específica. Estos niños deben ser tratados por un Comité Interdisciplinario de Malformaciones Craneomaxilofaciales para definir estrategias de seguimiento y tratamientos clínico-quirúrgicos. Se destaca que la distracción osteogénica es un recurso terapéutico de gran utilidad para estos pacientes

The Pierre Robin Sequence is a triad comprising retro-micrognatia, glossoptosis and cleft palate, with a prevalence of 1:8500. In about 40-50% of the cases the presentation is isolated, while in the rest it is a part of a complex malformation syndrome. Our objective was to evaluate the frequency of isolated and non-isolated presentation in patients with Pierre Robin Sequence diagnosed at the Genetics Service of the "Sup. Sor María Ludovica" Children Hospital of La Plata, also proposing a diagnostic and therapeutic scheme for each category. We did a retrospective study analyzing 83 patients with Pierre Robin Sequence which were diagnosed from 1993 to 2009. From these, 45 % (n=37) were isolated presentations, while 55% (n=46) presented complex patterns. In the last group, the genetic disorders were observed in 31 children, being Stickler syndrome (n=18) and Treacher Collins (n=5) were the most frequent. Di George syndrome (CATCH 22) (n=7) was the predominant chromosomic anomaly (n=11) and misoprostol, related to Moebius syndrome (n=4) was the predominant teratogen. Distraction osteogenesis was performed in 9 of all the patients, being 6 with isolated Pierre Robin Sequence and 3 with complex syndromes, with previous tracheostomy in 2 patients of each of these groups. Both titanium extraoral distractors and reabsorbable intraoral distractors were used, achieving mandibular elongations between 15 and 20 mm after an average of 21 days; this permitted the extraction of the tracheostomy tube in 3 of the 4 patients. In conclusion, our data present a good correlation with bibliographic reports. Faced with a patient presenting Pierre Robin Sequence, the neonatologist or the pediatrician should perform a thorough physical examination to detect dysmorphic features and order complementary tests which could orient the diagnosis of a specific syndrome. These patients should be analyzed by an Interdisciplinary Craniomaxillofacial Malformation Committee in order to provide adequate clinical and surgical treatment, being mandibular osteodistraction a valuable approach in these cases

Secuencia de Pierre Robin / Pierre Robin sequence

La secuencia de Pierre Robin es una triada compuesta por retromicrognatia, glosoptosis y fisura palatina con una prevalencia de 1:8500. El 40 a 50% son casos aislados, el resto forma parte de patrones malformativos complejos. Nuestro objetivo fue valorar la frecuencia de la secuencia de Pierre Robin como entidad aislada o formando parte de asociaciones malformativas y proponer para ambos grupos un esquema de diagnóstico y de recursos terapéuticos. Se realizó un estudio retrospectivo, descriptivo, de 83 pacientes portadores de secuencia de Pierre Robin de la Sala de Genética del Hospital de Niños "Sup. Sor María Ludovica" de La Plata, entre 1993 y 2009. El 45 % (n=37) fueron formas aisladas y el 55 % (n=46) formas sindrómicas. En este último grupo, las entidades génicas se observaron en 31 niños, siendo el síndrome de Stickler (n=18) y el síndrome de Treacher Collins (n=5) los más frecuentes. El síndrome de Di George (CATCH 22) (n=7) predominó entre las anomalías cromosómicas (n=11) y el misoprostol relacionado con el síndrome de Moebius (n=4) fue el teratógeno predominante. A 9 pacientes del total se les realizó distracción osteogénica (6 pacientes con secuencias de Pierre Robin aisladas y 3 con secuencias de Pierre Robin sindrómica), 2 pacientes de cada grupo fueron traqueostomizados previamente a la distracción. Se utilizaron distractores extraorales de titanio e intraorales de material reabsorbible, lográndose una elongación mandibular entre 15 y 20 mm, en un promedio de 21 días, que permitió evolutivamente la descanulación en tres de los cuatro pacientes traqueostomizados. Concluimos que nuestros datos se correlacionan con los informes bibliográficos. Ante un niño con secuencia de Pierre Robin, sugerimos a los neonatólogos y pediatras realizar un minucioso examen físico para detectar dismorfias y solicitar estudios complementarios orientadores de alguna entidad específica. Estos niños deben ser tratados con un Comité Interdisciplinario de Malformaciones...

The Pierre Robin Sequence is a triad comprising retro-micrognastia, glossoptosis and cleft palate, with a prevalence of 1:8500. In about 40-50% of the cases the presentation is isolated, while in the rest it is a part of a complex malformation syndrome. Our objective was to evaluate the frequency of isolated and non-isolated presentation in patients with Pierre Roben Sequence diagnosed at the Genetics Service of the "Sup. Sor María Ludovica" Children Hospital of La Plata, also proposing a diagnostic and therapeutic scheme for each category. We did a retrospective study analyzing 83 patients with Pierre Robin Sequence which were diagnosed from 1993 to 2009. From these, 45% (n=37) were isolatd presentations, while 55 % (n=46) presented complex patterns. In the last group, the genetic disorders were observed in 31 children, being Stickler syndrome (n=18) and Treacher Collins (n=5) were the most frequent. Di George syndrome (CATCH 22) (n=7) was the predominant chromosomic anomaly (n=11) and misoprostol, relatd to Moebius syndrome (n=4) was the predominant teratogen. Distraction osteogenesis was performed in 9 of all the patients, being 6 with isolated Pierre Robin Sequence and 3 with complex syndormes, with previous tracheostomy in 2 patients of each of these gropus. Both titanium extraoral distractors and reabsorbable intraoral distractors were used, achieving mandibular elongations between 15 and 20 mm after an average fo 21 days; this permitted the extraction of the tracheostomy tube in 3 of the 4 patients. In conclusion, our data present a good correlation with bibliographic reports. Faced with a patient presenting Pierre Robin Sequence, the neonatologist or the pediatrician should perform a thorough physical examination to detect dysmorphic features and order complementary tests which could orient the diagnosis of a specific syndrome. These patients should be analyzed by an Interdisciplinary Craneomaxillofacial Malformation Committee in order to provide...

Fixator-assisted nailing and consecutive lengthening over an intramedullary nail for the correction of tibial deformity.

We report the results of using a combination of fixator-assisted nailing with lengthening over an intramedullary nail in patients with tibial deformity and shortening. Between 1997 and 2007, 13 tibiae in nine patients with a mean age of 25.4 years (17 to 34) were treated with a unilateral external fixator for acute correction of deformity, followed by lengthening over an intramedullary nail with a circular external fixator applied at the same operating session. At the end of the distraction period locking screws were inserted through the intramedullary nail and the external fixator was removed. The mean amount of lengthening was 5.9 cm (2 to 8). The mean time of external fixation was 90 days (38 to 265). The mean external fixation index was 15.8 days/cm (8.9 to 33.1) and the mean bone healing index was 38 days/cm (30 to 60). One patient developed an equinus deformity which responded to stretching and bracing. Another developed a drop foot due to a compartment syndrome, which was treated by fasciotomy. It recovered in three months. Two patients required bone grafting for poor callus formation. We conclude that the combination of fixator-assisted nailing with lengthening over an intramedullary nail can reduce the overall external fixation time and prevent fractures and deformity of the regenerated bone.

Síndrome de Pierre Robin: relato de caso e sequência terapêutica / Pierre Robin Syndrome: report of case and therapeutic sequence

A síndrome de Pierre Robin é uma rara anomalia de desenvolvimento causada por mau posicionamento fetal, caracterizada por micrognatia, glossoptose, palato profundo ou fenda palatina, retrognatia e hipoplasia dos côndilos mandibulares. Desse modo, pode provocar problemas de ordem sistêmica, como obstrução das vias aéreas superiores, desnutrição, refluxo gastroesofágico, broncopneumonia e exaustão. Seu tratamento deve ser supervisionado por uma equipe médica multidisciplinar e deve ser realizado imediatamente após o diagnóstico. O presente trabalho tem por objetivo apresentar um caso típico de síndrome de Pierre Robin em uma criança do sexo feminino, leucoderma, com dois meses de idade e traqueostomizada, tratada através de distração osteogênica mandibular bilateral e de enxerto ósseo autógeno na região de sínfise mentoniana.

The syndrome of Pierre Robin is a rare developmental anomaly caused by bad fetal positioning, characterized by micrognathia, glossoptosis, profound palate or palatine rift, retrognathia and hipoplasy of mandibular condyles. Thus, it can provoke some systemic order problems, like obstruction of the superior airways, malnutrition, gastroesophagic reflux, bronchopneumonia and exhaustion. The treatment should be supervised by a multidisciplinary medical team and is immediately accomplished after the diagnosis. The purpose of the present work is to report a typical case of syndrome of Pierre Robin in a female child, white race, and 2 months-old, tracheotomized treated through bilateral mandibular distraction osteogenesis and bony graft in mandibular symphiseal region.

Estudo experimental da aplicação das forças de compressão ou distração sobre o sistema de fixação pedicular / Compression or distraction forces applied on a pedicular fixation system: an experimental study

Foi realizado estudo experimental com o objetivo de avaliar os efeitos da aplicação da força de compressão e distração (aproximação e afastamento) sobre os implantes colocados nos pedículos vertebrais. Foram utilizados no estudo os segmentos vertebrais T8-T9, T10-T11, T12-L1, L2-L3 e L4-L5 de suínos da raça Landsark. Cada segmento vertebral foi fixado com implantes pediculares, tendo sido aplicada força de compressão ou distração com deslocamento que variou de 5,1 mm a 9,35 mm. O deslocamento provocado pela aplicação das forças foi mensurado em quatro pontos do segmento vertebral: A (porção anterior do corpo vertebral), B (porção média do corpo vertebral), C (porção posterior do corpo vertebral) e D (processo articular siperior). A força de compressão produziu o afastamento dos pontos localizados nas regiões A e B, e aproximação dos pontos da região D. A força de distração produziu a aproximação dos pontos da região A e B e o afastamento dos pontos da região D.

An experimental study was conducted with the objective of evaluating the effects of compression and distraction (approach and deviation) forces applied on implants placed at vertebral pedicles. The vertebral segments T8-T9, T10-T11, T12-L1, L2-L3 and L4-L5 of Landsark pigs were used in the study. Each vertebral segment was fixed with pedicular implants, with compression or distraction forces being applied with a displacement that ranged from 5.1 mm to 9.35 mm. Displacement caused by forces application was measured in four points of the vertebral segment: A (anterior portion of the vertebral segment), B (medial portion of the vertebral segment), C (posterior portion of the vertebral segment) and D (superior joint process). Compression forces caused the deviation of points located at regions A and B, and the approach of points at region D. Distraction forces caused the approach of points at regions A and B and deviation of the points at region D.

Distração osteogênica na maxila com uso de ancoragem externa em pacientes fissurados / Maxillary distraction osteogenesis using a rigid external distraction (RED system) in cleft patients

A hipoplasia maxilar é comum nos pacientes portadores de fissuras lábio-palatais. O manejo para esta condição tem sido um desafio para a equipe reabilitadora. O tratamento convencional para correção de discrepâncias maxilo-mandibulares no sentido ântero-posterior consiste no uso de elásticos de tração anterior e cirurgia ortognática após o estágio de crescimento. Sabe-se que estes procedimentos têm resultados, muitas vezes, instáveis e insatisfatórios nas relações oclusais e sob o ponto de vista estético. A distração osteogênica tem se tornado uma técnica alternativa para tratar as displasias craniofaciais. Assim, este trabalho visa revisar a literatura e descrever a técnica de distração osteogênica com uso de ancoragem externa em pacientes fissurados com deficiência maxilar severa.

Tratamento da falha óssea parcial pelo transporte ósseo parietal / Partial bone defect treatment using parietal bone transportation

OBJETIVO: Descrever a técnica de transporte ósseo parietal para tratamento de falha óssea parcial, e descrever o resultado clínico e radiográfico de uma série de pacientes tratados por esta técnica. CASUíSTICA E MÉTODO: tratamos nove pacientes portadores de lesão óssea parcial, sendo seis localizada na tíbia e três no fêmur. Todos apresentavam lesão infectada, acompanhada de pseudo-artrose. O procedimento iniciou-se com estabilização do segmento ósseo com fixador externo, seguido de corticotomia parietal, em osso sadio adjacente à falha, para criar o fragmento que foi transportado. Este fragmento foi transfixado por fios olivados, que conectados às hastes sulcadas permitiam o transporte ósseo. Em dois pacientes os fragmentos utilizados eram de osso adjacente (fíbula), transportados para a tíbia em direção da tíbia. A latência, velocidade e ritmo de distração foram os preconizados por Ilizarov. RESULTADOS: a infecção e a pseudo-artrose foram curadas em todos os casos, com preenchimento da falha óssea. As complicações encontradas foram infecção nos orifícios dos fios na pele e regenerado hipotrófico. CONCLUSAO: o tratamento da falha óssea parcial pelo transporte ósseo parietal determinou solução do processo infeccioso, com consolidação da pseudo-artrose e preenchimento da falha óssea.

Fixação externa em fraturas de fêmur em crianças / External fixation in femur fractures in children

Em um estudo prospectivo, avaliamos os resultados da fixação externa em fraturas femorais em crianças. No período de 1997 a 2000, 24 crianças com 26 fraturas diafisárias de fêmur (23 fraturas fechadas e três expostas) foram tratadas com fixador externo. A média de idade dos pacientes foi de oito anos e oito meses (variando de seis a 13 anos). Todas as fraturas foram seguidas até seis meses após a consolidação, que ocorreu em 100 por cento dos casos, quando foi retirado o fixador externo com uma média de 87 dias (variando de 63 a 135 dias). A infecção através do trajeto dos pinos foi comum, mas nenhum paciente desenvolveu osteomielite. A principal complicação foi a refratura (17 por cento), que necessitou de novo procedimento com o fixador.

Correction of shortening and/or angular deformities by distraction osteogenesis using AO-tubular fixator.

Eighteen patients (20 bony segments) who had shortening and/or angular deformities were treated by distraction osteogenesis using AO-tubular external fixator. The mean angular correction was 18.9 degrees (range, 8-40 degrees). Of the group in whom shortening and angulation was corrected, the mean length gained was 4.2 cm (3-6 cm). The mean treatment time was 4.9 months (range, 2-13 months) and the mean follow-up was 12 months after removal of the fixator (range, 3-30 months). Delayed union with loosening of the fixator occurred in one patient which resulted in residual shortening of 1.5 cm. The author's technique of distraction osteogenesis using AO-tubular fixator with the new distraction rate of 1 mm/48 h (1 mm/step) could adequately correct shortening and/or angular deformities. No extra equipment was needed other than the readily-available AO-tubular fixation systems. No serious complications such as neurovascular injury were encountered.

Effect of low-intensity ultrasound stimulation on consolidation of the regenerate zone in a rat model of distraction osteogenesis.

This study was performed to explore the tissue-level changes in mineralization caused by low-intensity ultrasound stimulation after distraction osteogenesis. Unilateral femoral lengthenings (7 mm) were performed on 34 male Sprague-Dawley rats. Half of the animals received daily ultrasound stimulation for 5 weeks; the remaining animals received sham treatments. Healing was assessed with serial radiographs, quantitative micro-computed tomography, and biomechanical testing. Twenty-one animals were evaluated at the conclusion of the study (9 experimental, 12 control). Radiographically, healing of the ultrasound-treated bones preceded that of the sham-treated bones by approximately 1 week. Bone volume fraction and trabecular bone pattern factor were significantly higher in the ultrasound-treated animals, but there were no significant differences in bone mineral content or bone mineral density. The ultrasound-treated femurs were 20% stiffer and 33% stronger than the control femurs, but the differences were not statistically significant. These findings suggest that pulsed, low-intensity ultrasound matures the regenerate by altering the microarchitecture of the newly formed bone.

Vibratory coherence as an alternative to radiography in assessing bone healing after osteodistraction.

Distraction osteogenesis is used in orthopedics to lengthen bones by cutting or breaking the bone and gradually separating the two pieces as new bone fills the intervening space. There is a need for early assessment of the degree of bone healing that allows for normal functioning without unwanted side effects. This study compared different techniques used to evaluate the degree of bone healing during mandibular osteodistraction in 21 rabbits. For each rabbit, the mandible was cut in a surgical procedure and then 72 h later distraction began at a rate of 3 mm per day. Bone formation at the distraction site was assessed by in vivo photodensitometry on head radiographs, an in vivo (nondestructive) vibratory coherence test across the distraction site, a postmortem, ex vivo (destructive) three-point bending mechanical test, and by postmortem, ex vivo (destructive) histological examination. Statistical analyses included analysis of variance and correlation coefficient tests. The findings revealed that the results of bone photodensity and the mechanical three-point test are highly and positively correlated with the results of the vibration test. The use of the vibration test may provide a substitute for or augment the routine use of radiography for in vivo evaluation and monitoring of bone healing.

[Complications of distraction-compression osteogenesis and their prophylaxis--a clinical report]. / Niektóre aspekty powiklan osteogenezy dystrakcyjno-kompresyjnej oraz ich profilaktyka w swietle wlasnych doswiadczen klinicznych.

The authors present a historical overview of various classifications of distraction osteogenesis complications. Paley's classification as well as the authors' own classification also presented. Basing on the authors' own 10 year experiences with the Ilizarov method, selected complications at different stages of diagnostics, treatment and rehabilitation are presented. The most effective forms of prophylaxis are presented, with special attention given to the surgeon's own experience with the Ilizarov method.

The intramedullary skeletal kinetic distractor (ISKD): first clinical results of a new intramedullary nail for lengthening of the femur and tibia.

In 1986, a programme was initiated by the senior author to develop a reliable, mechanically activated, intramedullary lengthening device with a non-invasive means of measuring the progress of lengthening without X-ray. We report results of design, biomechanical testing, in vivo animal testing and clinical implantation of the first 20 intramedullary skeletal kinetic distractors (ISKDs) in adult patients with limb-length discrepancies. Twenty ISKD devices were implanted in 18 patients (14 males and four females). Lengthening was required due to infection (ten), trauma (six), polio (one) and burn (one). Six femurs and 14 tibias were lengthened. Mean patient age was 40 years (range, 18-65 years). No implant related infections, non-unions, malunions or joint contractures were observed. A design change was made following two initial hardware failures, after which there were no further breakages. Average lengthening was 49 mm (range, 29-110 mm). The average lengthening rate was 0.82 mm/day (range, 1.7-0.4 mm/day). Ability to work, walk and drive before, during and after treatment with the ISKD compared favourably with that of similar patients undergoing lengthening using the 'monorail' method in our practice. The ISKD appears to be a safe and cost-effective alternative to external fixators that reduces lifestyle disruption and complications during adult limb-lengthening procedures.

Force-displacement behaviour of biological tissue during distraction osteogenesis.

Limb lengthening and bone transport treatments are used frequently, and complications during treatment are common. Knowledge of the origin of tensile forces which resist distraction and the force-displacement response of biological tissues during extension would assist in reducing complication rates. Two tibial diaphyseal lengthenings carried out using an Ilizarov fixator were monitored by a displacement transducer to determine extension of the lengthening tissue (the regenerate bone), and by force transducers to determine tensile forces in the tissues that resist extension. The position of the force vector within a cross-section of the limb at the regenerate (provided by CT) was used to determine the origin of these forces. The muscle groups and adjacent fascia resisting extension were the gastrocnemius in one subject and the anterior and peroneal compartments in the other. In response to distraction, these tissues had relatively high stiffness (> 200 N/mm), less "immediate" displacement (< 35% of long term non-recoverable displacement) and inconsistent force relaxation properties (0-90%). In contrast, when the force vector was located in the vicinity of the regenerate, tissue exhibited lower stiffness (< 50 N/mm) and more immediate displacement (> 65% of long term nonrecoverable displacement), but also exhibited inconsistent force relaxation (0-67%).