Surgical Treatment of Subfibular Ossicle in Children: A Retrospective Study of 36 Patients with Functional Instability.

BACKGROUNDS: To evaluate the surgical management of a symptomatic subfibular ossicle after severe ankle sprain with functional instability and pain sequelae in children. METHODS: We analyzed 36 patients complaining of functional instability without laxity, 1 year after an ankle inversion trauma associated with the observation of a subfibular ossicle. We systematically suggested the open excision of the residual ossicles, followed by 6 weeks of immobilization and proprioceptive physiotherapy. Seventeen of them, constituting the "resection" group accepted this surgical approach. The remaining 19 patients, the "control" group, received only rehabilitative care. The American Orthopaedic Foot and Ankle Society ankle pain and function score was evaluated in both groups. RESULTS: The mean latest follow-up was 4 years and 4 months (range, 1 y 8 mo to 14 y 7 mo). A significant improvement of the American Orthopaedic Foot and Ankle Society score was observed and was significantly higher in the resection group with a mean gain of 31 points (SD=31.8), versus 7 points (SD=7) in the control group (P<0.001). CONCLUSIONS: We conclude that in the absence of objective laxity, excision of the os subfibulare appears as a simple and effective technique in the treatment of posttraumatic functional instability and ankle pain. LEVEL OF EVIDENCE: Level IV-retrospective case-control study.

Pediatric fracture reduction in the emergency department.

Limb fractures are a large part of pediatric trauma activity. Conservative treatment is possible because of children's bone remodeling potential. In case of displaced fractures, when a closed reduction can be done in the emergency room (ER), this avoids general anesthesia, hospitalization and the associated costs. In well-defined situations, there is a consensus about the indication for fracture reduction in the ER. Some complex fracture cases require immediate treatment in the operating room: intra-articular fractures, pathological fractures, fractures with associated skin, nerve or vascular injuries and/or early signs of compartment syndrome. And last, there is another set of fractures where the indication is not so clear. To specify the indications and technical implementation of these treatments in ER, we did a non-systematic narrative review of literature in the MEDLINE® database using the PubMed search engine to query "emergency room AND children AND fracture AND reduction". We retained the most recent articles addressing the questions related to indications and their care, sedation protocol and complications. The sedation protocol for the ER is established collaboratively by surgical, ER and anesthesia teams. The residual angulation that can be tolerated after reduction depends on the patient's age, remaining growth potential and location of the fracture line. When reduction is done in the ER, the complication and secondary displacement rates are not higher, although surgeon experience and specific procedural training appear to be crucial.

Granulocyte-colony stimulating factor enhances bone fracture healing.

BACKGROUND: Circulating mesenchymal stem cells contribute to bone repair. Their incorporation in fracture callus is correlated to their bioavailability. In addition, Granulocyte-colony stimulating factor induces the release of vascular and mesenchymal progenitors. We hypothesized that this glycoprotein stimulates fracture healing, and analyzed the effects of its administration at low doses on bone healing. METHODS: 27 adult male Sprague-Dawley rats underwent mid-femur osteotomy stabilized by centromedullar pinning. In a post (pre) operative group, rats were subcutaneously injected with 5 µg/kg per day of Granulocyte-colony stimulating factor for 5 days after (before) surgery. In a control group, rats were injected with saline solution for 5 days immediately after surgery. A radiographic consolidation score was calculated. At day 35, femurs were studied histologically and underwent biomechanical tests. FINDINGS: 5 weeks after surgery, mean radiographic scores were significantly higher in the Preop group 7.75 (SD 0.42) and in the Postop group 7.67 (SD 0.52) than in the control group 6.75 (SD 0.69). Biomechanical tests showed femur stiffness to be more than three times higher in both the Preop 109.24 N/mm (SD 51.86) and Postop groups 100.05 N/mm (SD 60.24) than in control 32.01 N/mm (SD 15.78). Mean maximal failure force was twice as high in the Preop group 68.66 N (SD 27.78) as in the control group 34.21 N (SD 11.79). Histological results indicated a later consolidation process in control than in treated groups. INTERPRETATION: Granulocyte-colony stimulating factor injections strongly stimulated early femur fracture healing, indicating its potential utility in human clinical situations such as programmed osteotomy and fracture.

Temporal evolution of mechanical properties of skeletal tissue regeneration in rabbits: an experimental study.

Various mathematical models represent the effects of local mechanical environment on the regulation of skeletal regeneration. Their relevance relies on an accurate description of the evolving mechanical properties of the regenerating tissue. The object of this study was to develop an experimental model which made it possible to characterize the temporal evolution of the structural and mechanical properties during unloaded enchondral osteogenesis in the New Zealand rabbit, a standard animal model for studies of osteogenesis and chondrogenesis. A 25 mm segment of tibial diaphysis was removed sub-periosteally from rabbits. The defect was repaired by the preserved periosteum. An external fixator was applied to prevent mechanical loading during osteogenesis. The regenerated skeletal tissues were studied by CT scan, histology and mechanical tests. The traction tests between 7 and 21 days post-surgery were done on formaldehyde-fixated tissue allowing to obtain force/displacement curves. The viscoelastic properties of the regenerating skeletal tissues were visualized throughout the repair process.

Aluminum and iron can be deposited in the calcified matrix of bone exostoses.

Exostosis (or osteochondroma) is the most common benign bone tumor encountered in children and adults. Exostoses may occur as solitary or multiple tumors (in the autosomal syndromes of hereditary multiple exostoses). Exostoses are composed of cortical and medullary bone covered by an overlying hyaline cartilage cap. We have searched iron (Fe) and aluminum (Al) in the matrix of cortical and trabecular bone of 30 patients with exostosis. Al(3+) and Fe(3+) are two cations which can substitute calcium in the hydroxyapatite crystals of the bone matrix. The bone samples were removed surgically and were studied undecalcified. Perls' Prussian blue staining (for Fe) and solochrome azurine B (for Al) were used on the histological sections of the tumors. Al(3+) was detected histochemically in 21/30 patients as linear bands deposited by the osteoblasts. Fe(3+) was detected in 10 out of these 21 patients as linear bands in the same locations. Fe(3+) and Al(3+) were not identified in the bone matrix of a control group of 20 osteoporotic patients. Energy X-ray Dispersive Spectrometry failed to identify Fe and Al in bone of these tumors due to the low sensitivity of the method. Wavelength Dispersive Spectrometry identified them but the concentrations were very low. Histochemistry appears a very sensitive method for Fe(3+) and Al(3+) in bone.The presence of these two metals in the exostoses advocates for a disturbed metabolism of osteoblasts which can deposit these metals into the bone matrix, similar to which is observed in case of hemochromatosis with Fe(3+).

Posterior shoulder dislocation in infants with neonatal brachial plexus palsy.

BACKGROUND: Glenoid dysplasia and posterior shoulder subluxation with resultant shoulder stiffness is a well-recognized complication in infants with neonatal brachial plexus palsy. It is generally considered to be the result of a slowly progressive glenohumeral deformation secondary to muscle imbalance, physeal trauma, or both. Recent publications about infantile posterior shoulder dislocation have suggested that the onset of dysplasia occurs at an earlier age than has been previously recognized. The prevalence of early dislocation in infants with this disorder has not been previously reported, to our knowledge. METHODS: We studied 134 consecutive infants with neonatal brachial plexus palsy who were seen at our institution over a period of two years. All infants were examined at monthly intervals to assess neurological recovery and the status of the upper extremity until recovery occurred or a treatment plan was established. The type of brachial plexus involvement was classified. Specific clinical signs associated with subluxation and dislocation were recorded. These included asymmetry of skin folds of the axilla or the proximal aspect of the arm, apparent shortening of the humeral segment, a palpable asymmetric fullness in the posterior region of the shoulder, or a palpable click during shoulder manipulation. The infants who were identified as having these clinical signs were evaluated with ultrasonographic imaging studies. RESULTS: Eleven (8%) of the 134 infants had a posterior shoulder dislocation. The mean age at the time of diagnosis was six months (range, three to ten months). There was no correlation between the occurrence of dislocation and the type of initial neurological deficit. A rapid loss of passive external rotation between monthly examinations indicated a posterior shoulder dislocation. CONCLUSIONS: Posterior shoulder dislocation can occur earlier (before the age of one year) and more rapidly in infants with neonatal brachial plexus palsy than has been appreciated previously. As with developmental dysplasia of the hip, a high index of suspicion, recognition of clinical signs, and the use of ultrasonography will allow the diagnosis to be established. Following early diagnosis, attention should be focused on improving the stability and congruency of the shoulder joint.

Osteochondritis dissecans of the lateral tibial condyle associated with agenesis of both cruciate ligaments.

Osteochondritis dissecans is a rare cause of painful knees in children. Only 10 cases of lateral tibial condyle involvement have been reported in the literature. Congenital agenesis of both cruciate ligaments has been described even less, and its prevalence is unknown. The authors report an atypical association of osteochondritis dissecans of the tibia with congenital absence of both cruciate ligaments. A 12-year-old male soccer player presented with a painful right knee. Magnetic resonance imaging revealed the diagnosis. The child was treated conservatively. At 18-month follow-up, radiographs showed osseointegration of the osteochondritis dissecans, and the patient had resumed normal athletic activity without pain. To the authors' knowledge, this is the only report describing such an association. The authors discuss the possible etiology of osteochondritis dissecans associated with agenesis of the cruciate ligaments and highlight the possibility of this association when osteochondritis dissecans of the tibia is diagnosed in a child with a painful knee. In this patient, the strain due to anteroposterior instability may have been the cause of osteochondritis. Conservative treatment should be considered in this setting.

Temporal evolution of skeletal regenerated tissue: what can mechanical investigation add to biological?

The objective here was to experimentally characterize the temporal evolution of the structural and mechanical properties of large volume immature regenerated tissues. We studied these evolving tissues from their genesis in controlled mechanical conditions. We developed an animal model based on the periosteal properties leading to unloaded regenerated skeletal tissue. To characterize the temporal evolution of mechanical properties, we carried out indentation tests coupled with macroscopic examinations and histological studies. This combined methodology yielded a range of information on osteogenesis at different scales: macroscopic by simple observation, mesoscopic by indentation test and microscopic by histological study. Results allowed us to identify different periods, providing a link between biological changes and material property evolution in bone tissue regeneration. The regenerated tissue evolves from a viscous, homogeneous, soft material to a heterogeneous stiffer material endowed with a lower viscosity. From a biological point of view, cell organization progresses from a proliferated cell clot to a mature structure closer to that of the bone. During the first 7 days, mechanical and biological results revealed the same evolution: first, the regenerated tissue grew, then, differentiated into an osteochondral tissue and finally calcification began. While our biological results confirm those of other studies, our mechanical results provide the first experimental mechanical characterization by reduced Young's modulus of such tissue.

Forearm compartment syndrome in the newborn: report of 24 cases.

PURPOSE: Isolated cases of ischemia, compartment syndrome, or Volkmann's ischemic contracture in the forearm of the newborn infant have been reported in the past. The purpose of this study is to review a large series of patients with neonatal forearm compartment syndrome and to report the important clinical features. METHODS: A search of medical records from 1980 to 2000 identified 24 children with evidence of ischemia of the forearm at the time of birth. Records and images were reviewed for prenatal and birth history, maternal factors, medical conditions, pattern of involvement, treatment, and outcomes. Patients were grouped according to the extent of initial soft-tissue involvement. RESULTS: All patients presented with a sentinel forearm skin lesion. Patterns of involvement ranged from mild skin and subcutaneous lesions to dorsal and volar compartment syndrome with or without distal tissue loss. Early treatment intervention was limited to a single case in which the diagnosis of compartment syndrome was made and an emergency fasciotomy was performed with a good outcome. In other cases tissue loss, compressive neuropathy, muscle loss, and late skeletal changes were responsible for impaired function. Distal bone growth abnormality was common. CONCLUSIONS: Forearm compartment syndrome in the newborn is not as uncommon as previously thought. The skin lesion was the common, salient, initial diagnostic finding. Early diagnosis and appropriate referral led to the salvage of a functional limb in 1 of the patients in this series. The severity of the initial insult correlated with the degree of impairment in growth and function. The delayed diagnosis and treatment of an evolving compartment syndrome may compromise further final function.