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Features Departments Information |
 John F. Sarwark, MD |
Current Topics in Children’s Orthopaedics John F. Sarwark, MD Abstracted with permission. The purpose of this update is to serve as a primary source and review for the pediatrician and other pediatric specialists. Topics selected have value for the practicing pediatrician. The material is not intended to represent the only, nor necessarily best knowledge, method or procedure appropriate for the medical situations discussed. INTRODUCTION Evidence Based Medicine and Outcomes Research The AAOS (American Academy of Orthopaedic Surgeons) has recently published an inventory of instruments online as part of the Bone and Joint Decade Monitor Project. A number of musculoskeletal instruments may be viewed at: www.aaos.org/wordhtml/research/outcomes/explain.htm. Health Care, Graduate Medical Education Among the current and future challenges for pediatrics is healthcare access and financing Graduate Medical Education to meet Pediatric Workforce needs. The American Academy of Pediatrics (AAP) states that reimbursement methods should be developed that cover all the healthcare needs of children.[1] Additionally, the AAP takes the position that there should be no financial barriers to access for pediatric specialty care.[2] The AAP in its analysis of subspecialty care in the workforce notes that pediatric subspecialists in most areas are facing strong competitive pressures in the market. In 15 of 17 subspecialties, a majority noted that there would be no need in their community for additional pediatric subspecialists in their particular discipline.[3] Culturally Competent Care When training pediatricians and pediatric subspecialists, it is imperative to place emphasis on enhancing the racial and ethnic diversity of providers.3 It is also imperative that educators remain involved in the training of pediatricians with respect to children with special healthcare needs and physical disabilities.[4] Human Embryo Research The National Institutes of Health and Congress have deliberated recently on human embryo research and continue to do so. The AAP position statement supports research in this area in order to "accelerate the pace of research on health issues with important implications for children."[5] EVIDENCE-BASED MEDICINE AND OUTCOMES STUDIES Pediatric Orthopaedic Outcomes Instruments The Pediatrics Outcomes Data Collection Instrument (PODCI)—Analysis of Normals Normal children should be expected to respond highly on all scores. The authors concluded that a child scoring in the 80s or less is functioning at a different level than the normal child.[6] When PODCI was compared against the Child Health Questionnaire (CHQ), the measures were found to have an important role in defining the outcomes of 242 children with orthopaedic problems.[7] Comparison of Three Outcomes Instruments The scores of three instruments were recently compared and contrasted. These instruments were the Activities Scales for Kids (ASK) the Child Health Questionnaire Parent Form (CHQ-PF-28) and the Pediatrics Outcomes Data Collection Instrument (PODCI). The ASK and the PODCI correlated highly and discriminated better than the CHQ-PF-28. The questionnaires were noted to be measuring different factors.[8] Health Related Quality of Life (HRQL) after Brace or Surgery for Idiopathic Scoliosis Danielsson, Wiklund, Pehrsson and Nachemson reported a consecutive series of patients treated for idiopathic scoliosis with either brace or fusion surgery and at least a 20-year follow-up. There were no differences with respect to sociodemographic data between surgically treated and brace treated patients, and patients treated were found to have approximately the same HRQL (health-related quality of life) as the general population using age- and sex-matched controls.[9] Outcomes after Clubfoot Surgery A pediatric functional status scale (FSIIr) assessment of long-term follow-up of clubfoot surgical repair noted that postoperative functional status did not differ from that of age-matched controls, after an average follow-up of 45 months.[10]  Dr. John Sarwark with a young patient. PEDIATRIC ORTHOPAEDIC DISEASES AND MANAGEMENT Manual Stretching for Congenital Muscular Torticollis in Infants This prospective study identified that controlled manual stretching is safe and effective when infants are seen before the age of one year. Surgical release of the sternocleidomastoid muscle is recommended only after the infant has undergone at least six months of controlled, manual stretching and has deficits of passive rotation, lateral bending of the neck >15 degrees and a tight muscular band.[11] Clinical Value of Routine Preoperative MRI in Idiopathic Pattern Scoliosis Drs. Do, Fras, Burke, Widman, Rawlins and Boachie-Adjei prospectively evaluated 327 consecutive patients with idiopathic scoliosis prior to arthrodesis and instrumentation of the spine. No patient required neurosurgical intervention or additional work-up as a result of the MRI findings. The authors concluded that MRI is not indicated in the routine preoperative assessment of patients with an idiopathic scoliosis curve pattern and normal neurological examination.[12] MRI Evaluation of Infantile Scoliosis In infants ages three or less, 19.6% (11 of 56) incidence of neural axis abnormalities was found; scoliosis >20 degrees; no neurological abnormalities; no syndrome diagnosis and no congenital abnormalities. The authors, Dobbs, Lemke, Morcuende, Weinstein, Bridwell and Sponseller, recommended a total spine MRI at presentation in infant patients with scoliosis >20 degrees. Not stated in the report was whether the series was prospective or consecutive.[13] MRI Evaluation of Congenital Spine Abnormalities Suh, Sarwark and coworkers noted a 31% incidence of significant intraspinal anomalies in 41 nonrandomized children referred for MRI evaluation. Some of these patients had normal neurological examinations. A case was made recommending MRI evaluation as part of the initial evaluation of children with congenital scoliosis and spine abnormalities.[14] Bracing of Male Idiopathic Scoliosis The success rate of bracing for idiopathic scoliosis in males is different than in females, as noted by Karol, at the Texas Scottish Rite Hospital. Males are generally braced at an older age than their female counterparts and compliance is often difficult. Skeletal immaturity and thoracic curves were risk factors, as in female idiopathic scoliosis.[15] Etiology of Idiopathic Scoliosis Current knowledge of the etiology of idiopathic scoliosis is discussed in the cited Current Concepts Review. The reader is encouraged to refer to this update. In short, the true etiology of idiopathic scoliosis remains unknown. The etiology is probably multifactorial, with a single-gene disorder with variable penetrance suggested. A possible defect in processing by the central nervous system affecting the growing spine may have a role.[16] Repeat Surgical Interventions for Idiopathic Scoliosis Reoperations following initial spinal instrumentation and arthrodesis occur, perhaps more commonly than was thought. Richards noted a 14% reoperation rate, often for hardware prominence, shifting or deep infection. This potential should be communicated in the preoperative period with the family.[17] Spinal Deformity in Familial Dysautonomia (FD) Axelrod, Burke and coworkers in a large center that provides comprehensive FD care, recently noted an 83% prevalence of spinal deformity among those with FD who lived at least 20 years. By age 10 years, 52% had scoliosis and 21% had kyphosis with or without scoliosis. Curves progressed in 89% of patients despite bracing, and 37% had undergone spinal arthrodesis.[18] Spinal Deformity Progression and Pulmonary Function in Duchenne Muscular Dystrophy (DMD) Authors in Sapporo, Japan, noted a relationship between severe progression of spinal deformity and vital capacity (VC) of less than 1,900 mL in children less than 14 years. In these cases, VC can be used as an indicator of severity of spinal deformity in DMD.[19] Cervical Spine Problems in Adult Down Syndrome Older individuals with Down syndrome continue to have problems with the cervical spine. These problems include atlantoaxial instability (AAI) and precocious degenerative changes in the subaxial cervical spine, with or without cervical myelopathy. Pathologic conditions are to be expected in individuals over 30 years of age.[20] Herring Lateral Pillar Classification of Perthes Disease These authors found good agreement for intra- and interobserver reliability in classifying radiographs using the lateral pillar classification for Perthes Disease. This method was reproducible and independent of pediatric orthopaedic experience.[21] Slipped Capital Femoral Epiphysis (SCFE) Slipped capital femoral epiphysis is a disorder of puberty that results from both biomechanical and biochemical factors. SCFE may be secondary to an associated endocrine dysfunction in a minority of cases. Loder proposed an age-weight test as a simple method of determining the necessity for further medical-endocrine evaluation. This study concludes that children who are less than 10 years or more than 16 years of age are 4.2 times more likely to have an endocrine etiology for their SCFE. Children whose body weight is less than 50th percentile are 8.4 times more likely to have an atypical form of SCFE.[22] Vascular Supply of Slipped Capital Femoral Epiphysis Children with affected hips, with stable SCFE and with unstable SCFE, underwent selective angiography prior to reduction. The authors conclude that the vascular injury occurs at the time of injury. This conclusion is based on observing opacification of the superior retinacular artery (SRA) in all stable slips and no filling in three of the unstable slips. The authors also conclude that reduction of SCFE does not necessarily contribute to the risk of avascular necrosis.[23] Botox for Infant Clubfoot After infants reached a treatment plateau with physical therapy, stretching, taping and splinting (French method) administration of botulinum toxin type A (BTX-A) allowed significant improvements in foot dorsiflexion and flexibility. The authors recommend its use as an adjunct to conservative care in resistant clubfoot cases.[24] What’s New in Diagnosis and Treatment of Juvenile Rheumatoid Arthritis (JRA) Outcomes of children with JRA are that after 10 years, 50% with polyarticular and systemic JRA and 40% of children with pauciarticular JRA will have active arthritis. Three major therapeutic interventions have improved the quality of life of children with JRA significantly. These are intraarticular joint injections of triamclonolane hexacetonide, weekly methotrexate and twice weekly subcutaneous etanercept. Etanercept is a biologic agent, a fusion protein, consisting of a portion of tumor necrosis factor (TNF) receptor linked to the Fc portion of IgG1. It binds to TNF and blocks its interaction with TNF receptors on cells. Risk of serious infection is notable, since it blocks the inflammatory response. An intravenous preparation is available, infliximab, a monoclonal anti-TNF agent.[25] PEDIATRIC ORTHOPAEDIC TRAUMA General Trauma Management/Child and Family Functioning Thompson and coworkers noted that some children and families experience adverse effects following a serious pediatric fracture during the year after the injury. Their study indicated that operative stabilization, particularly of femur fractures, might be advantageous to the child and family. Interviews were based on the National Health Interview Survey and the Child Health Status Scales (Vineland Adaptive Behavior Scale and Behavior Checklist).[26] Trauma Management and Effect of Delayed Fracture Treatment Skaggs and coworkers noted that operative irrigation and debridement of open fractures might be delayed more than six hours without increased risk of infection if children are given early parenteral antibiotics. Similar conclusions could not be made on patients with grade III open fractures and delay of greater than 24 hours.[27] School Sports Accidents Kelm and coauthors noted that about 5% of all school children sustain a serious injury during physical education each year. Most of the injured students were older, with the average age 13 years. Most common injuries were sprains, contusions and fractures, upper extremity more than lower extremity. Most common implicated sports were soccer and basketball. The authors emphasize the need to outline individualized programs and the need to reintegrate injured children into physical education once they have recovered.[28] Classification and Associated Injuries of Pediatric Pelvic Fractures Silber, Flynn and associates tabulated the classification and associated injuries in a large group of children with pelvic fractures. They noted multisystem injuries in 60%, and 50% with additional skeletal injuries. Death rate was 3.6% with the leading causes of death were head and/or visceral injuries. Hemorrhage as a life-threatening injury was not seen, and urethral injury was less common than in adults.[29] CT Classification and Management of Pediatric Pelvic Fractures CT scanning in pediatric pelvic fractures is less useful than in adult pelvic fractures. Silber, Flynn and associates noted that radiographs alone predicted the need and type of operative intervention, with less reliance placed on CT imaging. The average age of which the addition of CT scans assisted in a change of classification or management was 11.2 years.[30] Approaches to Pediatric Femoral Shaft Fractures An algorithmic approach to management of pediatric femur fractures is now achieving a greater degree of acceptance among orthopaedists. This developing consensus is mostly based on age, as reported recently by Sanders.[31] As a result of a 1998 Pediatric Orthopaedic Society of North America (POSNA) survey, operative treatment increasingly was preferred over nonoperative management as patient age increased. The trend in treatment is to treat femur fractures in older children operatively and younger children nonoperatively. The consensus on treatment is highly age dependent. Prevention Infant Walker Injuries In 1999, an estimated 8800 children younger than 15 months were treated in hospital emergency rooms in the United States for injuries associated with infant walkers, so say the American Academy of Pediatrics, Committee on Injury and Poison Prevention. Walkers do not help a child to walk and can delay motor development. Since there is no clear benefit for their use, the AAP recommends a ban on the manufacture and sale of mobile infant walkers.[32] In-line Skating Injuries in Children Nguyen and Letts noted 331 injuries over a nine-year period that was associated with in-line skating by children. Fractures were 38% of all injuries. 61% of the injured were boys and the average overall age was 12 years. The upper extremity was more commonly injured; the head and neck were injured in 16%. Inexperience, lack of instruction and non-use of protective equipment were cited as risk factors for injuries.[33] SURGICAL TECHNIQUES Scoliosis Severe Spinal Deformities and Perioperative Halo-gravity Traction Management Colleagues at the Texas Scottish Rite Hospital reported on the utility of perioperative halo traction for treatment of severe scoliosis of varying etiologies. Most of the patients required interim spinal osteotomy. Traction applied was used for 6 to 21 weeks, and after definitive spinal fusion and instrumentation, improvement was seen in all. The trunk balance was improved in the frontal and sagittal planes, and surgery was enhanced by the improved alignment.[34] Severe Congenital Spinal Deformities and Expansion Thoracoplasty Campbell has developed an approach for treatment of severe congenital spine anomalies utilizing uses an innovative rib implant, particularly for those associated with growth inhibition and associated restrictive lung disease. The untreated spine and pulmonary problems can, in many cases, be progressive and insidious. Using expansion thoracoplasty, both the concave and convex sides of the spine grow, allowing the thoracic spine to grow in length. An improved pulmonary benefit may be expected.[35] Flexible Nailing of Pediatric Femoral Shaft Fractures Flexible intramedullary nailing of femur fractures in children and adolescents has been demonstrated to be effective.[36] Flexible pins are placed from the distal femoral metaphysis in a retrograde manner. Generally, two pins of the same diameter are placed, one medial and one lateral. Their combined diameter should fill approximately 80% of the canal width. Analysis of results of this approach shows shorter hospital stay and reduced need for the alternative of longer-term skeletal traction followed by spica casting. It is advisable to offer immobilization in a spica cast for many of these cases in the early post-operative period. Arthrodesis of the Hip in Adolescents Karol et al reported on gait function in individuals with arthrodesis of the hip during adolescence and made recommendations for pelvi-femoral position in consideration of their findings. Motion analysis revealed excessive motion at the level of the lumbar spine and at the level of the ipsilateral knee. Pain was associated with the abnormal motion and was directly related to duration of follow-up The authors recommend an intraoperative position of the hip of neutral abduction-adduction, 20 to 25 degrees of flexion and neutral rotation.[37] Physeal Stapling for Idiopathic Genu Valgum Stevens and colleagues reported on 152 knees (76 patients) that had undergone hemiphyseal stapling for adolescent idiopathic genu valgum as an alternative to osteotomy and were followed to maturity. Improvement in gait, clinical symptoms and radiographic parameters was reported. The procedure is reported as safe and effective, and no premature physeal closure was observed.[38] Calcaneal Lengthening For Severe Flat Foot Deformities Mosca reintroduced the concept of lengthening the neck of the calcaneus with a structural graft for valgus deformities of the foot and confirmed the usefulness of this method with clinical follow-up in 1995. Recently, Davitt, Armstrong and associates reported further confirmation of the effectiveness of the procedure using the AOFAS ankle and hindfoot scoring system, plantar pressure measurements and radiographic parameters on both pre- and postoperative evaluations. These authors noted improvement in all parameters, including improved weight shifting on plantar pressure measurements, improved talocalcaneal coverage angle and improvement in the talo-first metatarsal angle on the lateral view. The average AOFAS score was 90.[39] Clubfoot Non-operative care including gentle manipulation and serial casting for the infant with intrinsic clubfoot demonstrated effectiveness as a definitive intervention. Protocols using the Ponseti (Iowa) method of casting and early percutaneous Achilles tendon lengthening and protocols using the Demiglio (French) method of early physiotherapy have been demonstrated to reduce the number of severe clubfoot subjects requiring surgery. The surgical procedure is noted to be expensive and time consuming.[40] The successful results of these non-operative methods suggest that the great majority of babies with intrinsic clubfoot have satisfactory outcomes without additional extensive surgery. Foot Deformity in Duchenne Muscular Dystrophy Surgery, consisting primarily of posterior tibial tendon transfer with or without tendoachilles lengthening corrects and maintains foot position and can prolong ambulation. Not all patients need surgery to prolong ambulation, however. Regardless of the desire to continue ambulation, all patients should have this surgery after appropriate discussion with the patient, family and other caregivers.[41] Transplantation of Allografts for Physeal Problems Stevens and associates studied the feasibility of microvascular transplantation of epiphyseal plate allografts in subjects of different ages in an animal model. Successful transplantation was confirmed. Interestingly, growth rate was found to depend on the age of the donor epiphyseal plate and was independent on the age of the recipient.[42]
BIBLIOGRAPHY 1. Scope of healthcare benefits for newborns, infants, children, adolescents, and young adults through age 21 years. American Academy of Pediatrics. Committee on Child Health Financing. Pediatrics. 1997; 100(6): 1040–1. 2. American Academy of Pediatrics. Committee on Child Health Financing. Guiding principles for managed care arrangements for the health care of newborns, infants, children, adolescents, and young adults. Pediatrics. 2000; 105(1 Pt 1): 132–5. 3. Stoddard, J.J., et al., Providing pediatric subspecialty care: A workforce analysis. AAP Committee on Pediatric Workforce Subcommittee on Subspecialty Workforce. Pediatrics. 2000; 106(6): 1325–33. 4. Sneed, R.C., W.L. May, and C.S. Stencel, Training of pediatricians in care of physical disabilities in children with special health needs: results of a two-state survey of practicing pediatricians and national resident training programs. Pediatrics. 2000; 105(3 Pt 1): 554–61. 5. American Academy of Pediatrics. Committee on Pediatric Research and Committee on Bioethics. Human embryo research. Pediatrics. 2001; 108(3): 813–6. 6. Haynes, R.J. and E. Sullivan, The Pediatric Orthopaedic Society of North America Pediatric Orthopaedic Functional Health Questionnaire: an Analysis of Normals. J Pediatr Orthop. 2001; 21(5): 619–21. 7. Vitale, M.G., et al., Capturing Quality of Life in Pediatric Orthopaedics: Two Recent Measures Compared. J Pediatr Orthop. 2001; 21(5): 629–635. 8. Pencharz, J., et al., Comparison of three outcomes instruments in children. J Pediatr Orthop. 2001; 21(4): 425–32. 9. Danielsson, W., Pehrsson, Nachemson. Health Related Quality of Life in Patients with Adolescent Idiopathic Scoliosis- A Matched Follow-up at Least Twenty Years after Treatment with Brace or Surgery, Scoliosis Research Society. 2001; Cleveland, Ohio. 10. Roye, B.D., et al., Patient-based outcomes after clubfoot surgery. J Pediatr Orthop. 2001; 21(1): 42–9. 11. Cheng, J.C., et al., Clinical determinants of the outcome of manual stretching in the treatment of congenital muscular torticollis in infants. A prospective study of eight hundred and twenty-one cases. J Bone Joint Surg Am. 2001; 83–A (5): 679–87. 12. Do, T., et al., Clinical value of routine preoperative magnetic resonance imaging in adolescent idiopathic scoliosis. A prospective study of three hundred and twenty-seven patients. J Bone Joint Surg Am. 2001; 83–A(4): 577–9. 13. Dobbs, L., Morcuende, Weinstein, Bridwell, Sponseller. Incidence of Neural Axis Abnormalities in Infantile Patients Diagnosed with Idiopathic Scoliosis: Is a Screening MRI Necessary?, Scoliosis Research Society. 2001; Cleveland, Ohio. 14. Suh, S.W., et al., Evaluating congenital spine deformities for intraspinal anomalies with magnetic resonance imaging. J Pediatr Orthop. 2001; 21(4): 525–31. 15. Karol, L. The Efficacy of Bracing in Male Idiopathic Scoliosis, Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 16. Lowe, T.G., et al., Etiology of idiopathic scoliosis: current trends in research. J Bone Joint Surg Am. 2000; 82–A(8): 1157–68. 17. Richards, B.S. Repeat Surgical Interventions Following "Definitive" Instrumentation and Fusion for Idiopathic Scoliosis, Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 18. Hayek, S., et al., Spinal deformity in familial dysautonomia. Prevalence, and results of bracing. J Bone Joint Surg Am. 2000; 82–A(11): 1558–62. 19. Yamashita, T., et al., Correlation between progression of spinal deformity and pulmonary function in Duchenne muscular dystrophy. J Pediatr Orthop. 2001; 21(1): 113–6. 20. Mardjetko, S.M., O’Brien, M., Chicoine, B., Basobas, L.J. Survey of the Cervical Spine in a Population of Adults with Down Syndrome, Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 21. Podeszwa, D.A., et al., The effect of pediatric orthopaedic experience on interobserver and intraobserver reliability of the herring lateral pillar classification of Perthes disease. J Pediatr Orthop. 2000; 20(5): 562–5. 22. Loder, R.T. and M.L. Greenfield, Clinical characteristics of children with atypical and idiopathic slipped capital femoral epiphysis: description of the age-weight test and implications for further diagnostic investigation. J Pediatr Orthop. 2001; 21(4): 481–7. 23. Maeda, S., et al., Vascular supply to slipped capital femoral epiphysis. J Pediatr Orthop. 2001; 21(5): 664–7. 24. Delgado, M.R., et al., A preliminary report of the use of botulinum toxin type A in infants with clubfoot: four case studies. J Pediatr Orthop. 2000; 20(4): 533–8. 25. Sherry, D.D., What’s new in the diagnosis and treatment of juvenile rheumatoid arthritis. J Pediatr Orthop. 2000; 20(4): 419–20. 26. Stancin, T., Kaugars, A.S., Thompson, G.H., Taylar, H.G., Yeates, Y.O., Wade, S.I., Drotar, D. Child and Family Functioning, 6 and 12 Months Following a Serious Pediatric Fracture, Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 27. Skaggs, D.L., et al., Effect of delay of surgical treatment on rate of infection in open fractures in children. J Pediatr Orthop. 2000; 20(1): 9–22. 28. Kelm, J., et al., School sports accidents: analysis of causes, modes, and frequencies. J Pediatr Orthop. 2001; 21(2): 165–8. 29. Silber, J.S., et al., Analysis of the cause, classification, and associated injuries of 166 consecutive pediatric pelvic fractures. J Pediatr Orthop. 2001; 21(4): 446–50. 30. Silber, J.S., et al., Role of computed tomography in the classification and management of pediatric pelvic fractures. J Pediatr Orthop. 2001; 21(2): 148–51. 31. Sanders, J.O., et al., Treatment of femoral fractures in children by pediatric orthopedists: results of a 1998 survey. J Pediatr Orthop. 2001; 21(4): 436–41. 32. American Academy of Pediatrics. Committee on Injury and Poison Prevention. Injuries associated with infant walkers. Pediatrics. 2001; 108(3): 790–2. 33. Nguyen, D. and M. Letts, In-line skating injuries in children: a 10-year review. J Pediatr Orthop. 2001; 21(5): 613–8. 34. Sink, E.L., et al., Efficacy of perioperative halo-gravity traction in the treatment of severe scoliosis in children. J Pediatr Orthop. 2001; 21(4): 519–24. 35. Campbell, R.M., Vocke, A.K. Growth of the Thoracic Spine in Congenital Scoliosis After Expansion Thoracoplasty in Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 36. Flynn, J.M., et al., Titanium elastic nails for pediatric femur fractures: a multicenter study of early results with analysis of complications. J Pediatr Orthop. 2001; 21(1): 4–8. 37. Karol, L.A., S.E. Halliday, and Gourineni, Gait and function after intra-articular arthrodesis of the hip in adolescents. J Bone Joint Surg Am. 2000; 82(4): 561–9. 38. Stevens, M., et al., Physeal stapling for idiopathic genu valgum. J Pediatr Orthop. 1999; 19(5): 645–9. 39. Davitt, J.S., B.A. MacWilliams, and F. Armstrong, Plantar pressure and radiographic changes after distal calcaneal lengthening in children and adolescents. J Pediatr Orthop. 2001; 21(1): 70–5. 40. Williams, J.J., Shapiro J., Kahn, A., Panozzo, S. Treatment Outcomes and Cost analysis Using the French Taping Technique for Severe Clubfeet, Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 41. Scher, D.M., Mubarak, S.J. Surgery for the Prevention of Foot Deformity in Patients with Duchenne Muscular Dystrophy, Pediatric Orthopaedic Society of North America. 2001; Cancun, Mexico. 42. Stevens, D.G., M.I. Boyer, and C.V. Bowen, Transplantation of epiphyseal plate allografts between animals of different ages. J Pediatr Orthop. 1999; 19(3): 398–403. ACKNOWLEDGEMENTS I am grateful to John Grayhack, MD, and Erik King, MD, for their editorial review, and to Laura Powers Lemke, MD, for her assistance with the bibliography search.
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