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Dive into the research topics where Francois Lalonde is active.

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Featured researches published by Francois Lalonde.


Journal of Bone and Joint Surgery, American Volume | 2002

Surgical correction of residual hip dysplasia in two pediatric age-groups.

Francois Lalonde; Steven L. Frick; Dennis R. Wenger

Background: The goal of operative treatment of hip dysplasia or subluxation in children is to normalize the hip joint to delay or prevent the premature onset of osteoarthritis. In theory, intervention in early childhood, when the remodeling potential is greater, should provide the best opportunity for the development of a normal joint. Methods: To determine the efficacy of early surgical intervention in restoring the normal morphology of the hip, according to radiographic criteria, we reviewed the cases of thirty-six children (fifty hips) with residual dysplasia or subluxation who were managed with either a femoral and/or a pelvic osteotomy when they were between two and eight years old (Group I). The average age at the time of surgery was 3.7 years, and the average duration of follow-up was 4.3 years. We compared these results with those achieved in fourteen patients (eighteen hips) with residual hip dysplasia or subluxation who were treated surgically at an older age, between eight and eighteen years old (Group II). The outcome was assessed with use of clinical as well as multiple radiographic criteria. We believe that a normal relationship between the acetabulum and the femoral head was established when there was an acetabular index of <20° or a Sharp angle of <42°, a center-edge angle of >20°, and an intact Shentons line. Results: At the time of the latest follow-up, sixteen of the seventeen hips with residual dysplasia that had been treated with pelvic osteotomy alone in Group I and three of four such hips in Group II had a normal relationship between the acetabulum and the femoral head. Normal radiographic findings were noted in fifteen of the seventeen hips with residual subluxation that had been treated with combined femoral and pelvic osteotomies in Group I compared with four of eight such hips in Group II. Conclusions: We found that residual hip dysplasia or subluxation could be more predictably corrected, with normal radiographic results and with less morbidity and fewer complications, in children who were between two and eight years old than in those who were between eight and eighteen years old. Long-term follow-up is required to confirm whether the improved anatomy and function of the hip that resulted from early correction of residual dysplasia or subluxation lasts into adulthood.


Journal of Pediatric Orthopaedics | 2010

Advanced containment methods for Legg-Calvé-Perthes disease: Results of triple pelvic osteotomy

Dennis R. Wenger; Maya E. Pring; Harish S. Hosalkar; Christine Caltoum; Francois Lalonde; Tracey P. Bastrom

Background Although surgical containment has become a mainstay for the treatment of Legg-Calvé-Perthes (LCP) disease; traditional operations (varus osteotomy of femur, Salter osteotomy) have certain limitations, sometimes resulting in a prolonged limp or inadequate containment. This paper presents the surgical method and results of triple pelvic osteotomy for containment treatment of LCP disease. Methods This retrospective review of 39 children (40 hips; age 5 to 13 y) with LCP disease treated with triple pelvic osteotomy (1995 to 2005) included preoperative lateral pillar assessment and other measurements. Final follow-up films (minimum 3 y, range 3 to 9 y) were assessed using the modified Stulberg classification. Clinical follow-up evaluation assessed limp, limb-length inequality, range of motion, and activity level. Results Twenty-one (53%) hips were graded as lateral pillar B and 19 (48%) were lateral pillar C. Four patients required further treatment before the final follow-up. At final follow-up, 42% had a good outcome (Stulberg I/II), 47% had a fair outcome (Stulberg III), and 11% had a poor outcome. Thus, 89% of patients had satisfactory (good or fair) results. There was a significant difference in outcome based on the preoperative lateral pillar, with B hips more likely to have a good outcome (65%) compared with lateral pillar C hips (12.5%) (P=0.002). There were no lateral pillar B patients with a poor outcome. Seventeen percent of the lateral pillar C patients more than or equal to age 8 had a poor outcome compared with 50% being more than age 8 with a poor outcome. Four patients (3 lateral pillar C, 1 lateral pillar B) required further surgery. Conclusions Triple pelvic osteotomy resulted in maintenance of head shape in lateral pillar B patients of all ages and in younger lateral pillar C patients. Lateral pillar C patients over age 8 were more difficult to treat, however, we still advise containment for these cases because methods are now available to deal with containment failure. Triple pelvic osteotomy is an effective treatment method for LCP patients with lateral pillar B disease and younger patients with lateral pillar C disease. This method provides effective containment, which allows prolonged remodeling while avoiding the limitations of femoral varus osteotomy (limp, short limb) and Salter osteotomy (incomplete containment). Level of Evidence Level IV.


Journal of Pediatric Orthopaedics | 2008

Displaced olecranon fractures in children: a biomechanical analysis of fixation methods.

Stefan Parent; Michelle Wedemeyer; Andrew Mahar; Megan Anderson; Frances D. Faro; Suzanne Steinman; Francois Lalonde; Peter O. Newton

Background: Wire and suture methods have been used to stabilize pediatric olecranon fractures. This study (1) compared differences in simulated intraoperative compression during fracture reduction, (2) evaluated articular surface compression during cyclic loading of the tension band, and (3) compared fracture stabilization after cyclic physiologic loading at low/high levels. Methods: Identical olecranon fractures were created in 10 synthetic ulnas and randomized to suture or wire fixation. Compression after fixation and compression during cyclic loading between 10 and 50 N was measured with a load cell at the articular surface and compared with a 1-way analysis of variance (p < 0.05). Twenty-four fractured synthetic ulna were randomly assigned to wire or suture tension band constructs and low- or high-loading groups. The low-load group (12 ulnae) cycled loading from 3 to 10 N for 100 cycles followed by a failure test. The high-load group (12 ulnae) experienced 10 to 100 N before failure testing. Fracture separation (mm) and failure load (N) were compared using a 2-way analysis of variance (p < 0.05). Ten synthetic ulnae were randomized to wire/suture groups and cyclically loaded between 10 to 50 N while measuring loads across the fracture using a load cell. Correlation data were statistically compared with a Fisher transformation and z test (p < 0.05). Results: Residual compression was statistically greater for wire compared with suture. There was no difference in fracture displacement between groups during low loads. Suture had significantly greater displacement compared with wire at high loads. Failure loads were significantly greater for wire at both load settings. Wires transmitted forces across the joint surface more readily than sutures. Conclusions: Suture tension bands had lower ultimate failure loads and less compression at the fracture site. However, if low loads are expected or if the fracture is reduced easily, the suture tension band may be an appropriate alternative to wire fixation. Clinical Relevance Perhaps, in small children or when using casts in bigger children, a bioabsorbable suture may be used for fracture stabilization avoiding the need for extensive surgery to remove the fixation material.


Journal of Pediatric Orthopaedics | 2007

The healing forearm fracture: a matched comparison of forearm refractures.

Avi C. Baitner; Andrew Perry; Francois Lalonde; Tracey P. Bastrom; Jeff Pawelek; Peter O. Newton

Background: Forearm fractures in children usually heal rapidly after closed treatment. Recent studies report forearm refracture rates of 5%. The purpose of this study was to identify risk factors for refracture based on radiographic variables. Methods: We performed a retrospective review of patients that sustained a second forearm fracture (refracture) between 1998 and 2005. Refractures were defined as having a second fracture of the same forearm within 18 months of the original fracture. A comparison group of single-fracture patients followed in a capitated insurance plan were included and matched based on age and sex. Radiographic assessment included initial/final angulation, displacement, and fracture-line visibility at latest follow-up. Results: Sixty-three refractures were compared with 132 age- and sex-matched single-fracture patients. Time to refracture averaged 10 months. Thirty-eight percent of the initial fractures in the refracture group occurred in the proximal or middle third of the forearm compared with 15% for the single-fracture patients (P < 0.001). Because location of the fracture was found to be a risk factor for refracture, a secondary analysis was performed with refracture patients matched to single-fracture patients based on age, sex, bone fractured, fracture location, and treatment method. Fracture-line visibility of the radius at latest follow-up was clearly visible in 48% of refractures compared with 21% of controls (P = 0.05). Initial fracture severity and residual deformity were not significantly different. Conclusions: Proximal and middle one third forearm fractures are at greater risk of refracture compared with distal one third forearm fractures. There was a trend toward incomplete healing seen more commonly in those that refractured, emphasizing the importance of longer immobilization in these fractures. Level of Evidence: Prognostic study, level III, case-control study.


Journal of Pediatric Orthopaedics | 2003

Multiple-level thoracolumbar burst fractures in teenaged patients.

Ken C. Thomas; Francois Lalonde; Joseph O'neil; R. Merv Letts

The purpose of this study was to examine the characteristics of multiple-level burst fractures in teenaged patients. Five teenaged patients were identified with this injury pattern. The mean age at injury was 17.6 years. All five patients underwent a posterior fusion and an attempted decompression through ligamentotaxis. One of the five went on to have an anterior decompression. Four of the five patients had spinal instrumentation. Neurologic deficit was present in four patients. The proximal fracture was most often responsible for the neurologic deficit when present. The average length of follow-up was 4.5 years. There was no significant neurologic recovery after hospital discharge. Three of the five patients had minimal or no back pain at latest follow-up. The authors conclude that multiple burst fractures should be treated individually based on their clinical and radiographic characteristics.


Journal of Pediatric Orthopaedics | 1999

Air bags and children : A potentially lethal combination

Michael McCaffrey; Alan German; Francois Lalonde; Merv Letts

Air bags have been responsible for saving thousands of lives since their introduction in the early 1970s. Now, however, it has become apparent that under certain conditions, these restraint mechanisms designed to save lives have in fact been the cause of needless morbidity and mortality in children. We reviewed 13 children injured by air bags in Canada, where seat belt wear is mandatory for all occupants. Although 12 of the children sustained relatively minor air bag trauma, one child was killed by the air bag deployment, sustaining an occipital-C1 dislocation. The pediatric population is at particular risk as many parents continue to unwittingly place their children in the front seat and thus in jeopardy of sustaining air bag-induced injuries should a collision occur.


Journal of Pediatric Orthopaedics | 2007

Biomechanical stability of bioabsorbable screws for fixation of acetabular osteotomies.

Mark J. Adamczyk; Tim Odell; Richard Oka; Andrew Mahar; Maya E. Pring; Francois Lalonde; Dennis R. Wenger

The purpose of this study was to compare the biomechanical stability of triple innominate osteotomies fixed with either bioabsorbable or stainless steel screws. Triple innominate osteotomies were performed on composite hemipelves and fixed with either three 4.5-mm bioabsorbable screws or three stainless steel 4.5-mm screws. Two screws were placed from the iliac wing into the acetabular fragment, and 1 screw was placed from below the acetabular fragment into the iliac wing. Eight specimens for each screw type were biomechanically tested in an anatomical position (replicating weight bearing) and in a flexed and abducted position (replicating spica cast positioning). Specimens were cyclically loaded between 10 and 450 N to simulate the hip contact force in this population. Lower screws were then removed, and specimens were tested under identical conditions. Fragment displacement (mm) and construct stiffness (N/mm) were compared with a 2-way analysis of variance (P < 0.05). There were no significant differences between materials for fragment displacement or construct stiffness. Anatomical position showed significantly less displacement than spica position for both materials. Initial displacement in the spica position was significantly less during lower loads for stainless steel fixation. Bioabsorbable screws demonstrate comparable biomechanical stability to stainless steel screws in anatomical and spica positions at physiological loads. Flexion and abduction of the femur adversely affect the stability of the construct for both materials. Bioabsorbable screws behave similarly to steel screws when stabilizing triple innominate osteotomies and would have the advantage of not requiring a second surgery for screw removal. Confirmation of biocompatibility should be completed before widespread clinical application.


Journal of Pediatric Orthopaedics | 2014

Carbon dioxide gas arthrography for the evaluation of pediatric hip conditions: what is the risk and reliability?

Raymond Chan; John Schlechter; Shawn Nguyen; Francois Lalonde; Carl Weinert

Background: Various pediatric conditions often necessitate a morphologic examination of the hip joint in infancy or childhood, and multiple imaging options have been employed to achieve this goal. Arthrography is one such modality. Different types of contrast media have been utilized and include pharmacologic contrast agents, air, and carbon dioxide. There are scattered reports of complications related to the typical various media used during arthrography. Some of the most concerning are related to gas emboli following the use of air or carbon dioxide. This study assesses the potential complications of carbon dioxide hip arthrography in a series of children over a 12-year period. Methods: A retrospective review of the medical records of children between the ages of 0 and 3 years who underwent hip arthrography using carbon dioxide gas as the contrast medium was conducted. Outcome measures analyzed included volume of CO2 injected, vital signs, and perioperative and postoperative end-tidal CO2. Results: Our study population was comprised of 118 hips in 90 children. We found no correlation between the volume of CO2 injected and the patient’s vital signs or end-tidal CO2 at any point during the perioperative or postoperative period. None of the children exhibited any evidence for cardiopulmonary compromise or clinical signs of embolism. Discussion: To our knowledge, there have been no large studies reporting on carbon dioxide arthrography and its potential complications. There were no gas embolisms and/or cardiopulmonary complications in our patients in the perioperative, postoperative, or 1-year follow-up period. Utilizing carbon dioxide gas as the contrast media for hip arthrography in children is safe and can help aid in the treatment of pediatric hip conditions. Level of Evidence: Therapeutic Level IV.


Journal of Pediatric Orthopaedics | 1999

Congenital synspondylism: diagnostic features.

Francois Lalonde; Merv Letts; Darin Davidson

Congenital synspondylism is a recently described condition characterized by short stature, an unusual constellation of vertebral fusions without rib anomalies and carpal coalition. A new case is described to illustrate the diagnostic features and the orthopaedic problems associated with this rare syndrome. Review of available literature shows that patients with congenital synspondylism commonly develop spinal deformity and mild respiratory compromise.


Journal of Pediatric Orthopaedics | 2005

Intramedullary flexible nail fixation of unstable pediatric tibial diaphyseal fractures

Ryan C. Goodwin; Tracey Gaynor; Andrew Mahar; Richard Oka; Francois Lalonde

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Andrew Mahar

Boston Children's Hospital

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Dennis R. Wenger

Boston Children's Hospital

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Peter O. Newton

Boston Children's Hospital

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Maya E. Pring

Boston Children's Hospital

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Richard Oka

Boston Children's Hospital

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Tracey P. Bastrom

Boston Children's Hospital

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Merv Letts

University of Manitoba

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Andrew Perry

University of California

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Christine Caltoum

Boston Children's Hospital

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