Distraction Length Research Articles

External fixation reconstruction of the residual problems of benign bone tumours.

The mechanical features of and biologic response to using distraction osteogenesis with the circular external fixator are the unique aspects of Ilizarov’s contribution that allows deformity correction and reconstruction of bone defects. We present a retrospective study of 20 patients who suffered from a variety of benign tumours for which external fixators (EF) were used to treat deformity, bone loss, and limb-length discrepancy. A total of 26 bony segments in twenty patients (10 males, 10 females; mean age 17 years; range 7–58 years) were treated with EF for residual problems from the tumour itself (primary treatment) in 8 patients and for complications related to the primary surgery (secondary treatment) in 12 patients. Histological diagnoses were Ollier’s disease (n = 4), Fibrous Dysplasia (n = 5), Congenital multiple exostosis (n = 5), giant cell tumour (n = 2) and one case for chondromyxoid fibroma, desmoid fibroma, chondroma and unicameral bone cyst. Various types of external fixators used to treat these problems. These were Ilizarov, unilateral fixator, multiaxial correction frame (Biomet, Parsippany, NJ), Taylor spatial frame (Memphis, TN) and smart correction multiaxial frame. The mean follow-up time was 69.5 months (range 35–108 months). The mean external fixation time was 159.5 days (range 27–300 days). The mean external fixation index was 67.4 days/cm (12–610) in 26 limbs who underwent distraction osteogenesis. The mean length of distraction was 4.9 cm (range 0.2–14 cm). At final follow-up, all patients had returned to normal activities. Complications were in the form of knee arthrodesis in one patient, pin tract infection in six and residual shortening in eight patients. The use of EF and the principles of distraction osteogenesis, in the management of problems associated with benign bone tumours and related surgery yields successful results especially in young patients. With this approach, the risk for recurrence of shortening and deformity may be minimized with overcorrection or over-lengthening as dictated by preoperative planning.

Continuous distraction-induced delayed spinal cord injury on motor-evoked potentials and histological changes of spinal cord in a porcine model.

Experimental study. This study evaluated distraction-induced delayed spinal cord injury in a porcine model. Department of Orthopedics, Korea University Guro Hospital, Seoul, Korea. Global osteotomy of three columns was performed on the thirteenth thoracic vertebrae with 13 pigs. The osteotomized vertebrae were distracted to 57-103% of segmental vertebral height (SVH) length, which was less than the distraction length that induces prompt SCI. The vertebral height was maintained until the loss of motor-evoked potential (MEP) signals with continuous distraction. The distraction distance and the time at which SCI occurred were measured, and distraction was then released to observe MEP recovery patterns. We found delayed SCI in 8 of the 12 pigs, with a mean 20.9 mm (range 19-25 mm) and 10.7 min (range 8-12 min) of continuous spinal distraction, which was equivalent to 74.3% (68-84%) of SVH and 3.63% (3.42-4.31%) of thoracolumbar spinal length. A continuous 74.3% SVH distraction over an average of 10.7 min caused a delayed SCI, which was indicated by mild histologic changes in the spinal cord. Recovery patterns from SCI after distraction release were compatible with the degree of histological change; however, these patterns differed from the previously investigated prompt type of SCI. Late onset injury due to continuous spinal distraction, which is comparable to iatrogenic SCI in spinal correction surgery, is important for understanding the impact of corrective surgery.

Evaluation of the first experience of intramedullary nail lengthening using PRECICE® in a South African limb lengthening and reconstruction unit

BACKGROUND: Limb lengthening is performed through distraction osteogenesis after osteotomy and has traditionally been performed using external fixation. The PRECICE® Limb Lengthening System has recently emerged as an alternative method to control distraction. In this study, the first experience of intramedullary nail lengthening using PRECICE®, in a South African limb lengthening and reconstruction unit, was evaluated in terms of the accuracy of distraction and the number of implant-related complications that were reported METHODS: A total of nine patients underwent the limb lengthening procedure in 11 limb segments. Distraction of the nail was initiated by ERC (external remote controller) around 10 days after surgery at a distraction rate of 1 mm/ day. The distraction was monitored every 2 weeks by clinical and radiographic examinations. Ongoing physiotherapy rehabilitation was performed until consolidation was achieved RESULTS: A mean target distraction length of 45.18 mm (15 to 65 mm range) was obtained over an average follow-up period of 266 days, with an accuracy of 103% ± 18%. All the distraction segments united. Two complications were reported that were successfully treated CONCLUSION: Limb lengthening using the PRECICE® nail system was found to have excellent accuracy of distraction, which is reproducible between different segments and indications. Acceptable complication rates were observed in this study

Clinical utility of ultrasound to prospectively monitor distraction of magnetically controlled growing rods

Background ContextGrowing rods are commonly used for surgical treatment of skeletally immature patients with scoliosis, but require repeated surgeries for distractions and are fraught with complications. As an alternative, the use of magnetically controlled growing rods (MCGR) allows for more frequent non-invasive distractions to mimic normal growth. However, more plain radiographs are needed to monitor increased distraction frequency, thereby increasing ionizing radiation exposure to the developing child. The use of ultrasound, which emits no radiation, has been found in a cross-sectional study to be reliable in measuring MCGR distractions. PurposeThe study aims to address the prospective clinical utility of ultrasound compared with plain radiographs for assessing MCGR distractions. Study DesignThis is a prospective study. Patient SampleThe study includes patients with early-onset scoliosis undergoing distractions after MCGR implant. Outcome MeasuresThe distraction length on plain radiographs and ultrasound was measured. MethodsThis is a prospective study of patients treated with MCGR. Patients with both single- and dual-rod systems were included. Outpatient distractions were performed at monthly intervals, targeting 2 mm of distraction on each occasion. Assessment of distraction length was monitored by ultrasound at each visit; plain radiographs were taken every 6 months and were compared with ultrasound measurements. ResultsNine patients (5 female, 4 male), with a mean of 29 distractions (standard deviation [SD] ±14.3), were recruited. The mean distracted length per 6 months was 5.7 mm (SD ±3.6 mm) on plain radiographs and 5.2 mm (SD ±3.9 mm) on ultrasound for the concave rod, and 6.1 mm (SD ±3.6 mm) on plain radiographs and 5.9 mm (SD ±3.8 mm) on ultrasound for the convex rod. Excellent inter- and intra-rater reliabilities were observed for radiographic and ultrasound measurements. An excellent correlation was noted between the two imaging modalities (r=0.93; p<.0001). ConclusionsThis is the first prospective study to validate that ultrasound assessment of MCGR distraction lengths was highly comparable with that of plain radiographs. The present study has verified that ultrasound can be used to document length changes by distraction over time and that it had high clinical utility. Ultrasound can be a reliable alternative to plain radiographs, thereby avoiding radiation exposure and its potential detrimental sequelae in the developing child.

A low-cost method of craniofacial distraction osteogenesis

Distraction osteogenesis is an effective treatment modality for the correction of craniofacial deformities. The cost of these devices is significant and may preclude routine use of these distractors in developing countries. Hence, distraction osteogenesis was performed using medical equipment that was readily available in any hospital at minimal cost. From 2008 to 2013, a retrospective study was performed on infants and neonates who underwent primary distraction for craniofacial abnormalities. Midface or mandibular distraction was performed because of respiratory impairment and/or globe exposure. The apparatus used included Steinmann pins, stainless steel wires, attachment bolts, orthopaedic pulleys, string and intravenous bags for weights. For midface distraction, a transzygomatic pin was inserted, and a transmandibular pin or a cerclage wire was inserted into the mandible through the symphysis or body of the mandible and connected to the pulley system. Distraction osteogenesis was performed on five patients - three mandibular distractions (Pierre Robin sequence) and two transfacial distractions (Apert syndrome/Pfeiffer syndrome type III). The mean age, duration of distraction and duration of consolidation at the time of distraction was 60.5 days, 18.6 days and 16.4 days, respectively. The mean length of distraction achieved was 12mm. Common complications observed were pin loosening, pressure necrosis of the skin and uneven pull. A major disadvantage was the longer hospital stay required. The African method of distraction is effective, easy and cost effective and could be used in third-world hospitals where surgical expertise or expensive distraction sets are not freely available.

3D computed tomographic evaluation of the upper airway space of patients undergoing mandibular distraction osteogenesis for micrognathia.

SUMMARYMandibular distraction osteogenesis (MDO) is currently an accepted method of treatment for patients requiring reconstruction of hypoplastic mandibles. To date one of the unsolved problems is how to assess the quantitative increase of mandible length needed to achieve a significant change in the volume of the posterior airway space (PAS) in children with mandibular micrognathia following distraction osteogenesis. The purpose of this study is to present quantitative volumetric evaluation of PAS in young patients having distraction osteogenesis for micrognathia using 3D-CT data sets and compare it with pre-operative situation. In this observational retrospective study, we report our experience in five consecutive patients who underwent MDO in an attempt to relieve severe upper airway obstruction. Each patient was evaluated before treatment (T0) and at the end of distraction procedure (T1) with computer tomography (CT) in axial, coronal, and sagittal planes and three-dimensional CT of the facial bones and upper airway. Using parameters to extract only data within anatomic constraints, a digital set of the edited upper airway volume was obtained. The volume determination was used for volumetric qualification of upper airway. The computed tomographic digital data were used to evaluate the upper airway volumes both pre-distraction and post-distraction. The mean length of distraction was 23 mm. Quantitative assessment of upper airway volume before and after distraction demonstrated increased volumes ranging from 84% to 3,087% with a mean of 536%. In conclusion, our study seems to show that DO can significantly increase the volume of the PAS in patients with upper airway obstruction following micrognathia, by an average of 5 times. Furthermore, the worse is the starting volume, the greater the increase in PAS to equal distraction.

Effect of distraction osteogenesis in patient with tibial shortening after initial union of Congenital Pseudarthrosis of the Tibia (CPT): a preliminary study.

BackgroundThe purpose of our retrospective study was to evaluate the preliminary result of distraction osteogenesis in patient with tibial shortening after initial union of Congenital Pseudarthrosis of the Tibia (CPT).MethodsAll the CPT cases with tibial shortening after initial union managed by proximal tibial lengthening using Ilizarov technique were identified. All the patient charts and radiograms were reviewed.ResultsBetween March 2007 and January 2012, 11 CPT cases were included with an average follow-up of 41 months (range, 34–51 months). The mean age at surgery was 8.5 years (range, 3.9–14.5y). The average length of discrepancy was 5.6 cm (range, 2.0–8.2 cm). Eight (8) cases had radiological findings of proximal tibial dysplasia, while the other 3 cases had not. The average distraction length gained was 5.3 cm (range, 3.5–8.0 cm) with a mean elongation rate of 21.4 % (range, 15–30 %). The Healing Index (HI) was 63.1 d/cm (range, 47–77 d/cm). In the 8 patients with proximal tibial dysplasia, 5 cases had lateral callus, 3 had central callus, and poor bone regeneration was observed in all of them with an average HI of 67 d/cm. In the other 3 patients without proximal tibial dysplasia, concave shaped callus was identified with an average HI of 52.7 d/cm. None of the patients had re-fracture, nonunion, axis deviation or angulation of the distraction area. Ankle joint stiffness was found in 2 of the patients. No evidence of knee contracture was detected. There were 5 cases with pin-tract infection which was managed by pin-tract nurse and oral administration of antibiotics.ConclusionsWe concluded that proximal tibial lengthening after initial union of CPT was effective for management of tibial shortening, however it was characterized by poor bone regeneration with different types of callus from normal, greater healing index and prolonged fixator wearing. We recommended that tibial lengthening could be considered when the limb length discrepancy (LLD) was more than 4 cm in younger children after primary union of CPT.

Maxillary Distraction Osteogenesis Using a Rigid External Distractor

Maxillary distraction osteogenesis is a reliable treatment for cleft lip and palate with midfacial retrusion. The purpose of this study was to evaluate the results of long-term follow-up in patients with cleft lip and palate after maxillary distraction osteogenesis and to find clinical factors related to relapse. From February 2002 to June 2008, 21 patients with severe class III malocclusion were treated at our hospital. We performed distraction osteotomy with a rigid external distractor device. The distraction length was more than 15 mm in all patients. Preoperative and postoperative lateral cephalometric radiographs were used for analysis. The sella-nasion-subnasale, sella-nasion-supramentale, and point-A-point-B-nasion (sella-nasion-subnasale-sella-nasion-supramentale) angles were recorded. The timelines for follow-up were preoperatively, after distraction, after consolidation, at 3 years, and once fully grown (5- to 8-year follow-ups). A comparative analysis of clinical factors was performed for the relapsing and nonrelapsing groups. Of the 21 patients, 14 had relapsed. The mean age in the relapsing group was 9.1 years (7 boys and 7 girls) with 9 patients with unilateral cleft palate and 5 c bilateral cleft palate. The mean age in the nonrelapsing group was 11.7 years (4 boys and 3 girls) with 5 patients with unilateral cleft palate and 2 patients with bilateral cleft palate. Despite greater anterior overcorrection, relapse occurred owing to scar tissue retraction and mandibular compensatory hypertrophy. The results suggest that the younger the patient, the more likely relapse will occur.

Experience with Mandibular Reconstruction Using Transport-Disc-Distraction Osteogenesis

The goal of transport-disc-distraction osteogenesis (TDDO) is to restore bone continuity by using in-situ bone. It may be useful following trauma, gunshot injuries, or tumor ablation, especially when there may be contraindications at the donor site or for prolonged surgery. To the best of the authors' knowledge, this is the first time TDDO has been used for mandibular reconstruction reporting additional procedures, which include osseointegrated dental implants rehabilitation and orthognathic surgery. A retrospective study is performed analyzing all mandibular reconstruction cases that may be suitable for distraction from January 2006 to December 2011. A thorough description of the documented cases includes details about sex, gender, complications, duration of hospitalization, etiology, size, and location of the defect. Eight cases of mandibular reconstruction were included. Six cases correspond to mandibular ameloblastoma. The remaining two cases were mandibular gunshot comminuted fractures. Range of the defects was from 45 to 60 mm. Length of the transport disc was 15 to 20 mm. Protocolized technique consisted of 5 days of latency period, 19 to 45 days of activation term (average 30 days), and 8 to 12 weeks for consolidation. Mean distraction length achieved was 40.45 mm. We can conclude that TDDO is an alternative to conventional and more invasive procedures, when we face severe segmental mandibular defects reconstruction. It shows the potential to restore a better anatomical bone regeneration, also providing soft tissues and reducing donor-site morbidity. Patients' education and awareness about the proper use of the transport-disc-distraction device is important to optimize functional outcomes.

New-onset craniosynostosis after posterior vault distraction osteogenesis.

The aims of this study were to document the incidence of new-onset craniosynostosis (NOC) after posterior vault distraction osteogenesis (PVDO), to determine risk factors for the development of NOC, and to deduce the cranial ramifications of NOC. An institutional review board-approved retrospective review of all patients who underwent PVDO at the Children's Hospital of Philadelphia was performed. Demographics, perioperative data, as well as preoperative and postoperative three-dimensional computed tomographic scans were analyzed. Suture patency preoperatively and postoperatively was recorded.Thirty patients underwent PVDO for suspected increased intracranial pressure and/or severe turribrachicephaly from 2008 to 2013. Twenty-four patients had syndromic diagnoses. The average age at the time of PVDO was 2.03 years. Distraction distances ranged from 19 to 40 mm, with an average of 28.7 mm. Among the 19 patients who had patent lambdoid sutures before PVDO, new-onset lambdoid fusion was seen in 17 patients after PVDO (89.5%), whereas the suture remained open in 2 patients (10.5%). New-onset lambdoid fusion was not significantly associated with age at distraction (P = 0.28), sex (P = 0.47), length of distraction (P = 0.93), or diagnosis (P = 0.61). Similarly, new-onset sagittal synostosis was not associated with age at distraction (P = 0.06), sex (P = 0.64), length of distraction (P = 0.83), or diagnosis (P = 0.25). None of the patients who developed NOC had characteristic head shape changes such as mastoid bulges or scaphocephaly. New-onset lambdoid and sagittal synostoses occur frequently after PVDO. Although the diagnosis of NOC is obvious radiographically, the clinical importance of the diagnosis morphometrically, neurodevelopmentally, and in cranial growth has yet to be fully investigated.

Callus molding in external and internal distraction of mandible.

Distraction osteogenesis (DO) emerges to be a promising alternative to the traditional method of bone lengthening, by which a significant skeletal and soft tissue enlargement can be obtained in the hypoplastic area in a short period. Manipulations of the newly created callus (regenerate), during DO or as a single step molding procedure at the end of the distraction process, may be necessary to correct the mandibular position. To report the efficacy of callus molding (CM) - floating bone concept in the vertical lengthening of ramus by DO and creating a gonial angle in the difficult case of vector selection or surgically induced asymmetry. Retrospective analysis of patients who underwent DO of mandible followed by CM for correction of mandibular asymmetry at authors centers from 2008 to 2014 formed the study group. Only the mandibular distraction cases were included in the study. After the 5 days of latency period, the mandible was distracted at the rate of 1 mm/day. At the end of DO, CM was completed in the 1-3 weeks before consolidation. CM was done either by removing the lower screws with distractor in place or after removal of distractor based on case selection. Secondary maxillary correction by Le Fort I osteotomy using bone graft and further occlusion is corrected by postorthodontics if necessary. Splints were used during CM for predetermined occlusion. In all the cases, postoperative intermaxillary fixation was maintained for 8 weeks for stable ossification of the callus. The study group consist of four and five cases of external and internal distraction, respectively. Of the 9 patients who underwent DO, 6 were females and 3 were males. The mean age of the population ranged from 10 to 21 years with a mean age of 18 years. The average distracted length of the mandible was 23.55 mm ranging from 20 to 26 mm with the standard deviation of 1.95. The mean deviation of the mandible (crossbite) at the end of distraction was around 8.23 mm ranging from 5 to 12 mm with the standard deviation of 2.17. Of the total 9 cases, only in 3 cases CM is done during DO and the rest 6 cases the CM is done after removal of the distractor. Secondary maxillary correction by Le Fort I osteotomy was done for 4 cases, and postorthodontic correction was done in 3 cases. In all the 9 cases, 100% results (as assessed clinically and radiographically) achieved with the creation of perfect gonial angle. CM plays a crucial role in those cases where proper vector orientation is hindered because of anatomical difficulty for osteotomy cuts and parallel fixation of the distractor to ramus resulting in cross-bite with deviation toward the undistracted side. Manipulation of the regenerates would provide a precise achievement of gonial angle, minimizing the need for secondary corrections, and diminishing treatment duration and costs.

Cranial distraction osteogenesis: a proposal of minimal consolidation period.

Cranial distraction osteogenesis (DO) has many advantages for correcting skull deformities: Thus, DO is extensively used for the treatment of skull deformities. However, diverse, unexpected complications are associated with this procedure. In this study, we present the surgical outcomes and complications of DO. Moreover, we propose a modified protocol for DO to reduce complications. This is a retrospective study on managed patients that underwent DO between March 2008 and May 2013. Their clinical courses were reviewed. Distraction protocols were individually inspected, and the final surgical outcomes, including complications, were evaluated. During the study period, a total of ten patients (seven boys and three girls) were treated at our institute. The median distraction period was 20.5days (ranging from 17 to 50days). The range of total distraction length was 19-22mm. The median consolidation period was 96days (ranging from 0 to 343days). All patients achieved the goals of distraction. At follow-up evaluations, all patients, except one, showed good surgical outcomes in both head shape and neurologic symptoms. There were six patients with wound complications during the treatment period. Among them, the distractors were removed early in three patients. Interestingly, even these three patients, without a sufficient consolidation period, showed good outcomes. Although DO has many merits for correcting skull deformities, it frequently causes severe wound complications. To reduce these complications, we propose a modified protocol with a minimal or even no consolidation period.

Mandibular Distraction Osteogenesis in Patients with Pierre Robin Sequence: Preoperative Assessment Determines Success

Objectives: (1) Understand the importance of an interdisciplinary approach to the selection of patients with Pierre Robin sequence for mandibular distraction osteogenesis. (2) Recognize that unfavorable outcomes can be linked to inaccurate preoperative assessment. Methods: A retrospective review of 10 consecutive patients with Pierre Robin sequence who underwent mandibular distraction from July 2011 to July 2013 at Children’s Memorial Hermann Hospital was performed. Age at distraction, associated syndromes and medical conditions, pre- and postoperative sleep studies, and complications were evaluated. Follow-up ranged from 6 months to 2 years. Results: A total of 10 patients with Pierre Robin sequence underwent mandibular distraction. Two had defined syndromal diagnoses and two had undefined chromosomal abnormalities. Average pre and postoperative AHI were 31.5 and 4.5, respectively. Average distraction length was 24 mm. Eight of the 10 patients who underwent distraction had successful outcomes defined by relief of obstructive apnea, reduction in AHl, and improved feeding at 2 months. Two patients had unfavorable outcomes. One did not respond to the distraction procedure and had a delayed diagnosis of spinal muscular atrophy, ultimately resulting in death. The other patient had multiple congenital anomalies and failed to respond to the distraction. The patient had significant laryngomalacia on post distraction repeat L and B, required tracheostomy, and later died of cardiac shunt failure. Conclusions: In the properly selected patient, mandibular distraction in patients with Pierre Robin sequence can be successful. Preoperative assessment involves both art and science, but ultimately determines the success or failure of the distraction procedure.

Management of bone defects at tibial metaphysis by bone transport technique with linear-circular hybrid external fixators

Objective To report our successful clinical experience of managing tibial metaphyseal bone defects with linear-circular hybrid external fixators to restore limb functions.Methods We managed and fully followed 9 male patients with tibial metaphyseal bone defects from December of 2009 to February of 2013.They were aged from 25 to 66 years (average,45.0 years).Four had a proximal end and 5 a distal end affected;5 cases were infected and 4 non-infected.The average length of tibial shortening was 13.0 mm (from-2 to 30 mm) before operation;the mean length of bone defects was 8.3 cm (from 4 to 13 cm).The non-infected patients were managed with debridement and trimming at the defect end,and primary fixation with linear-circular hybrid external fixators,followed by immediate or delayed osteotomy and bone lengthening after one or two months at the normal metaphyseal end.The infected patients were managed with debridement and fixation before the defects were filled with antibiotics-impregnated bone cement or artificial bone.The osteotomy and bone lengthening was performed secondarily.The fixators were not removed until consolidation was noticed in both the distracted area and the docking site and the patients were able to ambulate without aids.Results On average the 9 were followed up for 22.4 months (from 16 to 35 months).They achieved bony healing in both the distracted area and the docking site.Their average distraction length was 8.9 cm (from 5 to 13 cm).The leg length discrepancy was 4 mm (from1 to 14 mm)shorter on average after operation except in one patient with shortening and equinus deformity who refused correction.The average external fixation index (EFI) was 1.8 month/cm (from 1.2 to 2.6 month/cm).No infection relapsed.According to Paley's criteria,the bony results were excellent in 7 and good in 2 cases,and the functional results were excellent in 4 and good in 5 cases.The total complication rate was 1.4 per patient.Conclusions Bone transport technique with linear-circular hybrid external fixators is effective in management of tibia1 non-union with metaphyseal bone defects because it can preserve functions of the adjacent joints and stabilize securely the small peri-articular segments of cancellous bone.However,surgeons should be prudent in stimulating bone union at the docking site by gradual compression through linear-circular hybrid external fixators.Autograft is strongly recommended at the docking site. Key words: Tibia; Ilizarov technique; Bone lengthening

A Craniometric Analysis of Posterior Cranial Vault Distraction Osteogenesis

Posterior cranial vault distraction osteogenesis has replaced fronto-orbital advancement in some centers as the first-line treatment in patients with syndromic craniosynostosis. Despite this fact, little has been written about its craniometric effects on children with syndromic craniosynostosis. A retrospective review of all patients who underwent posterior distraction was performed. Patient demographic, perioperative data, and preoperative/postoperative computed tomographic scans were reviewed. Volumetric and craniometric indices were calculated and measured using commercial three-dimensional imaging software. From 2008 to 2012, 22 patients underwent posterior vault distraction osteogenesis for suspected intracranial hypertension or severe turribrachicephaly. In 13 patients, this was the first cranial vault procedure performed, whereas eight had previous fronto-orbital advancement and one had parieto-occipital reshaping. Half of patients underwent posterior cranial vault distraction osteogenesis before age 1 year; the average age at surgery was 2.3 years (range, 0.3 to 14.1 years) and distraction length averaged 27.3 mm (range, 19 to 35 mm). Average length of surgery was 2.9 hours (range, 1.6 to 3.8 hours), and average blood loss was 400 ml (range, 200 to 600 ml). Total treatment length was 91 days (range, 48 to 147 days). Distraction length averaged 27.3 mm (range, 19 to 35 mm). Intracranial volume increase averaged 21.5 percent (range, 7.5 to 70.0 percent; p<0.0001) and 28.4 percent (range, 10.8 to 66.0 percent; p=0.01) in the subset of patients younger than 1 year. Posterior cranial height increased 12.2 percent (range, 0 to 35 percent; p=0.002), and basofrontal angle decrease averaged 3.9 percent (range, 0 to 12 percent; p=0.003), indicating a decrease in cranial height trajectory and improvement in frontal bossing. Posterior cranial vault distraction is a safe and effective operation that may lower risk of intracranial hypertension and abnormal skull morphology. Interestingly, cranial morphological benefits were seen both anteriorly and posteriorly. Therapeutic, IV.

Over 10-year follow-up of functional outcome in patients with bone tumors reconstructed using distraction osteogenesis

BackgroundThe aim of this study was to investigate the long-term functional capabilities of patients who underwent bone distraction for the treatment of bone defects caused by bone tumor excision. MethodsBone distraction was indicated for patients with stage IIB malignant bone tumors when chemotherapy was judged to be effective and an epiphysis could be preserved or for patients with low-grade or aggressive benign bone tumors. Twenty-two patients who underwent reconstruction with bone distraction and were followed up for at least 10years were retrospectively investigated. Patients included 8 males and 14 females, with a mean age of 25.3years. Tumor types included seven osteosarcomas, two osteofibrous dysplasias, one Ewing’s sarcoma, five low-grade osteosarcomas, two adamantinomas, and five giant cell tumors. Chemotherapy was performed during bone distraction in 8 cases. Bone transport was used in 17 cases, while shortening distraction was used in 5 cases. ResultsThe mean distraction length was 8.1cm, and the mean external fixation period was 301days. The average Musculoskeletal Tumor Society score (used to measure functional outcome) was 91.5% at mean follow-up of 202months. Fourteen patients were able to play sports without any difficulty. ConclusionsEpiphyseal preservation and reconstruction by bone distraction require both time and effort, but can provide excellent long-term outcomes, resulting in a stable reconstruction that functionally restores the natural limb.

Biomechanical assessment of a novel bone lengthening plate system — A cadaveric study

BackgroundAlthough many types of external fixators have been developed for distraction osteogenesis, all have some drawbacks. We recently developed a novel bone lengthening plate to overcome these problems. The purpose of this study is to conduct biomechanical analyses using cadavers to assess the stability of the bone lengthening plate in relation to distraction length and femoral bone mineral density. MethodsWe used human cadaveric femurs (n=18) to assess the effects of distraction length and bone mineral density on the biomechanical stability of the bone lengthening plate. After establishing control (n=6, 0mm lengthening) and experimental groups (n=12, 30mm lengthening), we measured biomechanical stability (structural stiffness, ultimate load, and displacement) under a compressive load. The experimental group was subdivided into a group with normal bone mineral density (n=6) and a group with osteoporosis (n=6), and the biomechanical stability of these groups was compared. FindingStructural stiffness differed significantly between the control (417.6N/mm) and combined experimental groups (185.6N/mm, p=0.002). Ultimate load also differed significantly between the control (1327.8N) and combined experimental (331.4N, p=0.002) groups. Bone mineral density was unrelated to structural stiffness (p=0.204), ultimate load (0.876), or displacement (0.344). In all cases, failure of the bone lengthening plate occurred at the longitudinal connectors, such as the connecting columns between the upper and lower plates, and the lengthening shaft of the bone lengthening plate. InterpretationThe biomechanical stability of the bone lengthening plate was affected by the lengthening length but not by bone mineral density. In addition, biomechanical stability during lengthening was most strongly influenced by the longitudinal connectors.

Distraction Osteogenesis and Free Nail Graft After Distal Phalanx Amputation

To describe the results in patients treated with distraction osteogenesis combined with free nail graft after distal phalanx amputation. We analyzed 14 patients with distal phalanx amputation (13 women). Mean age was 35 years. There were 9 amputations of the index finger, 3 of the middle finger, and 1 each of the thumb and ring finger. We started bone distraction 7 days after surgery, with 1 mm distraction every 3 days. After bone elongation, we inserted a free composite nail graft at the dorsal tip of the distracted finger. We evaluated distraction length, consolidation time, aesthetic result (using the Foucher and Leclère score), and complications. The mean bone elongation was 17 mm and mean consolidation time was 149 days. Nail cosmetic results were satisfactory; the mean total Foucher score was 14 out of 20. Mean individual scores were patient's opinion (7.8 out of 10), adequate length (1.2 out of 2.5), adequate alignment (1 out of 1), adequate width (1.8 out of 4), and dorsal scar quality (2.2 out of 2.5). The mean total Leclère score was 14 out of 20. All patients retained sensibility in the grafted area and none had healing abnormalities. The mean opinion about the donor site was 7.5 out of 8. Nail growth less than 50% occurred in 2 patients. Mean follow-up was 62 months. Distraction osteogenesis combined with free nail graft is a therapeutic option when replantation is not an option or when it fails. However, treatment takes time and requires the involvement of the patient, family, and medical team.

Piezoelectric Belts as a Method for Measuring Chest and Abdominal Movement for Obstructive Sleep Apnea Diagnosis

ABSTRACT.Distinguishing obstructive sleep apnea from central apnea depends upon accurate measure of chest and abdominal movement. American Academy of Sleep Medicine (AASM) polysomnography guidelines recommend the use of respiratory inductive plethysmography (RIP) belts but not piezoelectrode (PE) belts for measuring chest and abdominal movements. To compare these two sensors, we measured the signal amplitude for 10 RIP belts and 10 PE belts stretched by mechanical distraction across six distances (2.5 to 15.0 centimeters) and replicated 10 times for each belt. Amplitudes were measured using the Stellate Harmonie (Stellate Systems, Inc., Natus Medical, Inc., San Carlos, California, USA) recording system. A Pearson Product Moment Correlation coefficient was calculated. All RIP belts performed well at all distraction lengths and demonstrated linear performance. Eight of 10 PE belts performed well through all measures whereas, two showed nonlinear increase in signal on stretch of greater than 12.5 centimeters. Signals from PE belts highly correlated with the distance of distraction (r=0.96 to 0.99) and the RIP belts (r=0.98 to 0.99). These results suggest that PE belts perform similarly to RIP belts at distraction distances up to 10.0 centimeters. Further testing on biological models is needed to determine if PE belts are a suitable alternative for RIP belts in polysomnography.

Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series

Scoliosis in skeletally immature children is often treated by implantation of a rod to straighten the spine. Rods can be distracted (lengthened) as the spine grows, but patients need many invasive operations under general anaesthesia. Such operations are costly and associated with negative psychosocial outcomes. We assessed the effectiveness and safety of a new magnetically controlled growing rod (MCGR) for non-invasive outpatient distractions. We implanted the MCGR in five patients, two of whom have now reached 24 months' follow-up. Each patient underwent monthly outpatient distractions. We used radiography to measure the magnitude of the spinal curvature, rod distraction length, and spinal length. We assessed clinical outcome by measuring the degree of pain, function, mental health, satisfaction with treatment, and procedure-related complications. In the two patients with 24 months' follow-up, the mean degree of scoliosis, measured by Cobb angle, was 67° (SD 10°) before implantation and 29° (4°) at 24 months. Length of the instrumented segment of the spine increased by a mean of 1·9 mm (0·4 mm) with each distraction. Mean predicted versus actual rod distraction lengths were 2·3 mm (1·2 mm) versus 1·4 mm (0·7 mm) for patient 1, and 2·0 mm (0·2 mm) and 2·1 mm (0·7 mm) versus 1·9 mm (0·6 mm) and 1·7 mm (0·8 mm) for patient 2's right and left rods, respectively. Throughout follow-up, both patients had no pain, had good functional outcome, and were satisfied with the procedure. No MCGR-related complications were noted. The MCGR procedure can be safely and effectively used in outpatient settings, and minimises surgical scarring and psychological distress, improves quality of life, and is more cost-effective than is the traditional growing rod procedure. The technique could be used for non-invasive correction of abnormalities in other disorders. Ellipse Technologies.