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Dive into the research topics where Henry G. Chambers is active.

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Featured researches published by Henry G. Chambers.


Clinical Orthopaedics and Related Research | 1996

Complications of iliac crest bone graft harvesting

Edward D. Arrington; William J. Smith; Henry G. Chambers; Allan L. Bucknell; Nelson A. Davino

Autologous bone grafts harvested from the iliac crest are commonly used in reconstructive orthopaedic surgery. Autologous bone is used to help promote bone healing in fractures and to provide structural support for reconstructive surgery. The results of autologous bone grafting are more predictable than the use of xenografts, cadaveric allografts, or synthetic bone substitutes because autologous bone grafts provide osteoinductive and osteoconductive properties, are not immunogenic, and are usually well incorporated into the graft site. In a retrospective review of 414 consecutive cases of iliac crest bone graft procedures performed at Brooke Army Medical Center from 1983 to 1993, 41 (10%) minor and 24 (5.8%) major complications were identified. Minor complications included superficial infections, superficial seromas, and minor hematomas. Major complications included herniation of abdominal contents through massive bone graft donor sites, vascular injuries, deep infections at the donor site, neurologic injuries, deep hematoma formation requiring surgical intervention, and iliac wing fractures. Harvesting of iliac crest bone graft can be associated with significant morbidity. However, with adequate preoperative planning and proper surgical technique, the incidence of these complications can be reduced.


Gait & Posture | 1999

Double-blind study of botulinum A toxin injections into the gastrocnemius muscle in patients with cerebral palsy

David H. Sutherland; Kenton R. Kaufman; Marilynn P. Wyatt; Henry G. Chambers; Scott J. Mubarak

The purpose of this study was to quantify the gait of subjects receiving two injections of either botulinum A toxin or saline vehicle into the gastrocnemius muscle(s). The study group consisted of cerebral palsy patients who walked with an equinus gait pattern. This study was a randomized, double-blinded, parallel clinical trial of 20 subjects. All were studied by gait analysis before and after the injections. There were no adverse effects. Peak ankle dorsiflexion in stance and swing significantly improved in subjects who received the drug and not in controls. Results of this double blind study give support to the short term efficacy of botulinum toxin A to improve gait in selected patients with cerebral palsy.


Developmental Medicine & Child Neurology | 2005

Health-related quality of life of children and adolescents with cerebral palsy: hearing the voices of the children

James W. Varni; Tasha M. Burwinkle; Sandra A. Sherman; Kanela Hanna; Susan J Berrin; Vanessa L. Malcarne; Henry G. Chambers

The aim of the study was to determine whether pediatric patients with cerebral palsy (CP; 24.3% hemiplegic, 30.4% diplegic, 38.5% quadriplegic) can self-report their health-related quality of life (HRQOL) with the Pediatric Quality of Life Inventory Version 4.0 (PedsQL 4.0) Generic Core Scales. The PedsQL was administered to 148 families (84 males, 64 females; mean 10y, SD 3y 9mo, range 5 to 18y) recruited from a childrens hospital clinic and state medical therapy clinics. Sixty-nine children (47%) were able to self-report. Children with CP self-reported a significantly lower HRQOL (mean 65.9) than healthy children (mean 83.8). Children with CP self-reported a similar HRQOL to pediatric cancer patients receiving treatment (mean 68.9). Children diagnosed with quadriplegia (mean 49.4) self-reported more impaired HRQOL than children with diplegia (mean 69.1) and hemiplegia (mean 72.4). Parent-child concordance was lowest for emotional functioning. Providers and parents should obtain the childrens HRQOL perceptions whenever possible.


Developmental Medicine & Child Neurology | 2006

The PedsQL in pediatric cerebral palsy: reliability, validity, and sensitivity of the Generic Core Scales and Cerebral Palsy Module

James W. Varni; Tasha M. Burwinkle; Susan J Berrin; Sandra A. Sherman; Kanela Artavia; Vanessa L. Malcarne; Henry G. Chambers

This investigation determined the measurement properties of the Pediatric Quality of Life Inventory (PedsQL) 3.0 Cerebral Palsy (CP) Module. PedsQL 4.0 Generic Core Scales and 3.0 CP Module were administered to 245 families. Mean age of the 134 males and 107 females was 8 years 1 month (SD 4y 4mo; range 2-18y). The sample included children with hemiplegia (n=55), diplegia (n=84), and quadriplegia (n=85). Twenty eight children had a Gross Motor Function Classification System classification at Level I, 40 at Level II, 86 at Level III, 43 at Level IV, and 37 at Level V. Reliability was demonstrated for the PedsQL 4.0 (alpha=0.86 child, 0.89 parent) and CP Module (alpha=0.79 child, 0.91 parent). The PedsQL 4.0 distinguished between healthy children and children with CP. Construct validity of the CP Module was supported. Sensitivity of the PedsQL was demonstrated among children with different diagnostic categories and gross motor function.


The Journal of Physiology | 2011

Hamstring contractures in children with spastic cerebral palsy result from a stiffer extracellular matrix and increased in vivo sarcomere length

Lucas R. Smith; Ki Seok Lee; Samuel R. Ward; Henry G. Chambers; Richard L. Lieber

Non‐technical summary  Muscle spasticity, due to an upper motoneuron lesion, often leads to muscle contractures that limit range of motion and cause increased muscle stiffness. However, the elements responsible for this muscle adaption are unknown. Here we show that muscle tissue is stiffer in contracture compared to age‐matched children, implicating the extracellular matrix (ECM). However, titin, the major load‐bearing protein within muscle fibres, is not altered in contracture, and individual fibre stiffness is unaltered. Increased ECM stiffness is even more functionally significant given our finding of long in vivo sarcomeres which leads to much larger in vivo forces in muscle contracture. These results may lead to novel therapeutics for treating spastic muscle contracture.


Journal of Bone and Joint Surgery, American Volume | 2005

The effect of surgical delay on acute infection following 554 open fractures in children.

David L. Skaggs; Lauren Friend; Benjamin A. Alman; Henry G. Chambers; Michael Schmitz; Brett Leake; Robert M. Kay; John M. Flynn

BACKGROUND Traditional recommendations hold that open fractures in both children and adults require urgent surgical debridement for a number of reasons, including the preservation of soft-tissue viability and vascular status as well as the prevention of infection. Following the widespread use of early administration of antibiotics, a number of single-institution studies challenged the belief that urgent surgical debridement decreases the risk of acute infection. METHODS We performed a retrospective, multicenter study of open fractures that had been treated at six tertiary pediatric medical centers between 1989 and 2000. The standard protocol at each medical center was for all children to be given intravenous antibiotics upon arrival in the emergency department. The medical records of all children with open fractures were reviewed to identify the location of the fracture, the interval between the injury and the time of surgery, the Gustilo and Anderson classification, and the occurrence of acute infection. RESULTS The analysis included 554 open fractures in 536 consecutive patients who were eighteen years of age or younger. The overall infection rate was 3% (sixteen of 554). The infection rate was 3% (twelve of 344) for fractures that had been treated within six hours after the injury, compared with 2% (four of 210) for those that had been treated at least seven hours after the injury; this difference was not significant (p = 0.43). When the fractures were separated according to the Gustilo and Anderson classification system, there were no significant differences in the infection rate between those that had been treated within six hours after the injury and those that had been treated at least seven hours after the injury. Specifically, these infection rates were 2% (three of 173) and 2% (two of 129), respectively, for type-I fractures, 3% (three of 110) and 0% (zero of forty-four), respectively, for type-II fractures, and 10% (six of sixty-one) and 2% (two of thirty-seven), respectively, for type-III fractures (p > 0.05 for all three comparisons). CONCLUSIONS In the present retrospective, multicenter study of children with Gustilo and Anderson type-I, II, and III open fractures, the rates of acute infection were similar regardless of whether surgery was performed within six hours after the injury or at least seven hours after the injury. The findings of the present study suggest that, in children who receive early antibiotic therapy following an open fracture, surgical debridement within six hours after the injury offers little benefit over debridement within twenty-four hours after the injury with regard to the prevention of acute infection.


American Journal of Sports Medicine | 2009

Correlation of Throwing Mechanics With Elbow Valgus Load in Adult Baseball Pitchers

Arnel Aguinaldo; Henry G. Chambers

Background Studies have shown that various biomechanical factors affect valgus extension overload during baseball pitching; yet, their relationships are not clearly defined, and factors such as trunk rotation and arm slot have not been investigated. Hypothesis The onset of trunk rotation, with other biomechanical variables that define sequential body motion, will significantly predict elbow valgus loading. Study Design Descriptive laboratory study. Methods Sixty-nine adult baseball players pitched off an indoor mound during 3-dimensional motion analysis to measure whole body kinematics and kinetics at 240 Hz. Thirteen biomechanical variables were calculated and extracted for regression analysis to investigate their associations with elbow valgus load. A 2-way analysis of variance compared valgus torques between pitchers with 2 onsets of trunk rotation (before and after front-foot contact) and 2 arm slot positions (overhand and sidearm). Results Six biomechanical variables had significant correlations (P < .02) with elbow valgus torque—with maximum shoulder external rotation, elbow flexion at peak valgus torque, and elbow valgus loading rate accounting for 68% of its variance. Reduced elbow valgus torques were associated with increased elbow flexion (P < .01). Players who initiated trunk rotation before front-foot contact had significantly higher elbow valgus torques than did those who rotated afterward (P = .02). Fourteen pitchers displayed a sidearm delivery and had significantly higher elbow valgus torques than did those with an overhand arm slot position. Conclusion Valgus torque at the elbow during baseball pitching is associated with 6 biomechanical variables of sequential body motion. A condition of late trunk rotation, reduced shoulder external rotation, and increased elbow flexion appeared to be most closely related to valgus torque. Sidearm pitchers appeared to be more susceptible than overhand pitchers to reduced elbow valgus torque. Clinical Relevance The biomechanical findings of this study offer scientific feedback for developing methods used to minimize the effects of valgus load on pitching-related elbow injuries.


Journal of Pediatric Orthopaedics | 2003

Relationships among musculoskeletal impairments and functional health status in ambulatory cerebral palsy.

Mark F. Abel; Diane L. Damiano; John S. Blanco; Mark R. Conaway; Freeman Miller; Kirk W. Dabney; D.H. Sutherland; Henry G. Chambers; Luciano Dias; John F. Sarwark; John T. Killian; Scott Doyle; Leon Root; Javier LaPlaza; Roger F. Widmann; Brian D. Snyder

Orthopedic surgery for patients with cerebral palsy addresses motion impairments, assuming that this will improve motor function. This study evaluates the relationships among clinical impairment measures with standardized assessments of function and disability as an initial step in testing this assumption. A total of 129 ambulatory children and adolescents across six institutions participated in a prospective evaluation that consisted of passive motion and spasticity examination of the lower extremities, three-dimensional gait temporal-spatial and kinematic analysis, and administration of the Gross Motor Function Measure (GMFM) and the Pediatric Outcomes Data Collection Instrument (PODCI). The analysis found that isolated impairment measures of motion and spasticity were only weakly related to motor function in cerebral palsy and even when averaged across multiple joints yielded no more than a fair correlation with functional scores, nor did a combination of impairments emerge that could predict substantial variance in motor function. These findings suggest that caution should be exercised when anticipating functional change through the treatment of isolated impairment and that addressing multiple impairments may be needed to produce appreciable effects.


Journal of Pediatric Orthopaedics | 1999

Intramedullary Kirschner wire fixation of open or unstable forearm fractures in children.

Scott Shoemaker; Christopher P. Comstock; Scott J. Mubarak; Dennis R. Wenger; Henry G. Chambers

This retrospective review evaluates the efficacy of standard intramedullary Kirschner wires (K-wires) for the treatment of open or unstable diaphyseal forearm fractures in 32 children with a mean follow-up of 13 months. Thirty-one patients had an excellent result, and one patient had a good result. Average time to bridging cortex was 3 months. Four patients lacked full pronation and supination, with none lacking >20 degrees, and no patients had evidence of growth-plate arrest. Nine complications occurred in eight patients: lost reduction after K-wire removal (three), refracture (two), deep infection (one), pin-site infection (one), transient anterior interosseous nerve palsy (one), and skin ulcer over buried K-wire (one). Both infections occurred in cases in which the K-wire ends were left outside the skin. Each case of lost reduction occurred in single-bone fixation cases when the K-wires were removed before 4 weeks. In children, intramedullary fixation by using standard K-wires plus cast immobilization provides effective treatment for the problematic open or unstable diaphyseal forearm fracture when closed management has failed. Refinement of the technique may help to avoid complications. We now recommend burying the K-wires under the skin for 3-5 months and stabilizing both the radius and ulna with an intramedullary K-wire.


Gait & Posture | 1996

Injection of botulinum A toxin into the gastrocnemius muscle of patients with cerebral palsy: a 3-dimensional motion analysis study

David H. Sutherland; Kenton R. Kaufman; Marilynn P. Wyatt; Henry G. Chambers

Abstract Botulinum A toxin (BOTOX ® ) was injected into the gastrocnemius muscle of 26 cerebral palsy subjects with equinus gait. All subjects were equinus walkers without fixed contracture of the triceps-surae muscle. Injections were performed at 3 month intervals, if needed, as determined by the treating clinician. There were 14 subjects with spastic hemiplegia, 11 subjects with spastic diplegia and 1 subject with spastic quadriplegia. In the case of those subjects with bilateral equinus gait the dose was divided and given into both the right and left gastrocnemius muscle. Gait analysis data was collected prior to the first injection and subsequently at 3 month intervals for 1 year. Kinematic and electromyographic data was obtained. This data was analyzed to provide objective information about the outcome of treatment. Four subjects moved away and were lost to follow-up. Seven subjects left the study to have surgery. The data collected revealed statistically significant improvements in dynamic ankle dorsiflexion in both stance and swing phases, stride length, and electromyography of the tibialis anterior. There were no complications. While the results of this study are promising, additional prospective studies are needed to determine the feasibility of preventing muscle contractures over a longer time period. Furthermore, there is a need for inclusion of other muscles in future research. Future research should also compare BOTOX ® treatment with alternative methods of dealing with muscle spasticity such as: casting, orthotic devices, physical therapy, selective dorsal rhizotomy, and surgical lengthening.

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Eric W. Edmonds

Boston Children's Hospital

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D.H. Sutherland

Boston Children's Hospital

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Kevin G. Shea

Saint Luke's Health System

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Marilynn P. Wyatt

Boston Children's Hospital

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Scott J. Mubarak

Boston Children's Hospital

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Allan L. Bucknell

United States Department of Veterans Affairs

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Dennis R. Wenger

Boston Children's Hospital

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