Predictive simulations identify potential neuromuscular contributors to idiopathic toe walking.

BACKGROUND: Most cases of toe walking in children are idiopathic. We used pathology-specific neuromusculoskeletal predictive simulations to identify potential underlying neural and muscular mechanisms contributing to idiopathic toe walking. METHODS: A musculotendon contracture was added to the ankle plantarflexors of a generic musculoskeletal model to represent a pathology-specific contracture model, matching the reduced ankle dorsiflexion range-of-motion in a cohort of children with idiopathic toe walking. This model was employed in a forward dynamic simulation controlled by reflexes and supraspinal drive, governed by a multi-objective cost function to predict gait patterns with the contracture model. We validated the predicted gait using experimental gait data from children with idiopathic toe walking with ankle contracture, by calculating the root mean square errors averaged over all biomechanical variables. FINDINGS: A predictive simulation with the pathology-specific model with contracture approached experimental ITW data (root mean square error = 1.37SD). Gastrocnemius activation was doubled from typical gait simulations, but lacked a peak in early stance as present in electromyography. This synthesised idiopathic toe walking was more costly for all cost function criteria than typical gait simulation. Also, it employed a different neural control strategy, with increased length- and velocity-based reflex gains to the plantarflexors in early stance and swing than typical gait simulations. INTERPRETATION: The simulations provide insights into how a musculotendon contracture combined with altered neural control could contribute to idiopathic toe walking. Insights into these neuromuscular mechanisms could guide future computational and experimental studies to gain improved insight into the cause of idiopathic toe walking.

Joint kinematic calculation based on clinical direct kinematic versus inverse kinematic gait models.

Most clinical gait laboratories use the conventional gait analysis model. This model uses a computational method called Direct Kinematics (DK) to calculate joint kinematics. In contrast, musculoskeletal modelling approaches use Inverse Kinematics (IK) to obtain joint angles. IK allows additional analysis (e.g. muscle-tendon length estimates), which may provide valuable information for clinical decision-making in people with movement disorders. The twofold aims of the current study were: (1) to compare joint kinematics obtained by a clinical DK model (Vicon Plug-in-Gait) with those produced by a widely used IK model (available with the OpenSim distribution), and (2) to evaluate the difference in joint kinematics that can be solely attributed to the different computational methods (DK versus IK), anatomical models and marker sets by using MRI based models. Eight children with cerebral palsy were recruited and presented for gait and MRI data collection sessions. Differences in joint kinematics up to 13° were found between the Plug-in-Gait and the gait 2392 OpenSim model. The majority of these differences (94.4%) were attributed to differences in the anatomical models, which included different anatomical segment frames and joint constraints. Different computational methods (DK versus IK) were responsible for only 2.7% of the differences. We recommend using the same anatomical model for kinematic and musculoskeletal analysis to ensure consistency between the obtained joint angles and musculoskeletal estimates.

Elemental analysis of femoral bone from patients with fractured neck of femur or osteoarthrosis.

The elemental composition of bone has been determined by inductively coupled atomic emission and mass spectrometry to test the hypothesis that changes in major or minor elemental concentrations may contribute to the risk of fracture. Femoral bone was obtained from patients at operation for the treatment of fracture and compared with that of patients with osteoarthrosis and a necropsy control group. The data suggest that there are no major differences in bone elemental composition in patients with fractures compared with the control group. Bone adjacent to joints with osteoarthrosis tends to be less mineralized (per unit trabecular bone volume) than control bone and bone from fracture patients, and has significantly lower concentrations of boron, lead and, zinc. These observations may reflect the more rapid turnover of bone close to the arthritic joint.

Galeazzi fractures in children.

We have reviewed 41 children under 15 years of age with a fracture of the radius and disruption of the inferior radio-ulnar joint. Despite the fact that the joint injury had not at first been recognised in 41% of cases and a variety of treatments had been used, the final results of conservative management were generally good. The more distal the radial fracture, the greater were the problems encountered.

Medial humeral condyle fracture with an ipsilateral dislocated radial head.

We present the first reported case of a combined medial humeral condyle fracture with ipsilateral radial head dislocation. This injury was sustained by a 7-year-old girl following a fall on an outstretched hand. The operative technique is described. At 6-month follow-up, the patient had normal alignment of the limb and achieved full range of motion.

Two-year placebo-controlled trial of botulinum toxin A for leg spasticity in cerebral palsy.

BACKGROUND: The controlled evidence favoring botulinum toxin A (BtA) treatment for spasticity in cerebral palsy is based on short-term studies. METHODS: We conducted a randomized, double-blind, placebo-controlled, parallel-group study of BtA (Dysport) for leg spasticity in 64 children with cerebral palsy. For 2 years, the children received trial injections of up to 30 mu/kg every 3 months if clinically indicated. RESULTS: For the primary endpoints of Gross Motor Function Measure (GMFM) and Pediatric Evaluation of Disability Index (PEDI) scaled scores at 2 years (trough rather than peak effect), there were no differences between the mean change scores of each group. For the GMFM total score, the 95% CI of -4.81 to 1.90 excluded a 5-point difference in either direction, and a 2-point benefit with 95% confidence. There were no differences in adverse events. CONCLUSIONS: There was no evidence of cumulative or persisting benefit from repeated botulinum toxin A (BtA) at the injection cycle troughs at 1 year or 2 years. The dose was not enough to change spasticity measures and thus GMFM in this heterogeneous group. Ceiling effects in GMFM and Pediatric Evaluation of Disability Index (PEDI) may have reduced responsiveness. This finding does not deny the value, individually, of single injection cycles or prove that repeating them is unhelpful. In this regard, BtA treatment can be viewed in the same light as other temporary measures to relieve spasticity, such as oral or intrathecal agents: there is no evidence of continuing benefit if the treatment ceases. The study provides long-term, fully controlled adverse event data and has not revealed any long-term adverse effects.

Etiology of Freiberg's disease: ? trauma.

Freiberg's disease is osteochondritis of the metatarsal head(s) commonly occurring in adolescent girls. The true etiology is unknown. The authors present a case precipitated by a form of folk dancing popular among British schoolgirls.

Contralateral percutaneous adductor tenotomy. An aid to peroperative fluoroscopy in hip fracture fixation.

In 6 elderly patients with femoral neck fractures, contralateral hip disease made lateral fluoroscopy difficult. Percutaneous adductor tenotomy of the contralateral hip facilitated screening of guide-wire placement during the fixation of the fracture.

Tibia recurvatum as a complication of Osgood-Schlatter's disease: a report of two cases.

Premature fusion of the anterior part of the upper tibial epiphyseal plate is a rare complication of Osgood-Schlatter's disease. The resulting deformity is both unsightly and difficult to treat. We report two further cases and highlight the need for regular screening for this rare complication of a common disease.

Is laparotomy for small bowel obstruction justified in patients with previously treated malignancy?

We report 53 patients who developed small bowel obstruction some time after the treatment of a primary malignant tumour. Previous treatment of the primary tumour in these patients had been by abdominal surgery (22 patients) or pelvic radiotherapy (20 patients) but 11 of the patients had not received previous abdominal surgery or radiotherapy. All the patients had a laparotomy in an attempt to relieve the obstruction. Seventeen patients had a cause for the obstruction other than secondary malignancy. This was noted particularly when the patients had had pelvic radiotherapy, when radiation change of the ileum causing obstruction was common. Thirty-six patients had obstruction due to secondary tumour and it was found possible to overcome the obstruction in all but two of these. The operative mortality in the patients with secondary malignancy was 19 per cent, but 15 patients (42 per cent) survived for more than a year and the median survival was 11 months. It is concluded that a policy of aggressive surgical intervention is desirable in patients who develop small bowel obstruction after previous treatment for malignant disease.

Bilateral coexistent calcaneonavicular and talocalcaneal tarsal coalition: a case report.

Tarsal coalition refers to a union of two or more tarsal bones. The union may be fibrous, cartilaginous, or bony. The most common sites of tarsal coalition reported in the literature are the calcaneonavicular, the talocalcaneal, and, less commonly, the talonavicular areas. Bilateral coexistent multiple tarsal coalitions are a rare occurrence. The authors present a case report of a 17-year-old boy with bilateral coexistent calcaneonavicular and talonavicular bars. The diagnosis was established by radiographs and CT scanning. The patient was treated conservatively with immobilization of the foot in a below-knee walking plaster cast followed by the use of an orthosis with a lateral iron and a medial T strap. The patient was pain-free at 2-year follow-up.

Acute meningococcal infection--a case of monoarthrosis.

A case of septic arthritis in the right knee of a six-month-old girl is described. Neisseria meningitidis was grown from the purulent exudate from the knee joint. No other manifestations of meningococcal disease were observed. Complete recovery followed aspiration and treatment with benzyl penicillin.

Percutaneous Ethibloc injection in aneurysmal bone cysts.

OBJECTIVE: To investigate whether the injection of Ethibloc into aneurysmal bone cysts can be an effective treatment modality. DESIGN AND PATIENTS: Ethibloc is an alcoholic solution of zein (corn protein) which has thrombogenic and fibrogenic properties. Ten patients with aneurysmal bone cysts were treated with CT-guided percutaneous injection of Ethibloc into the cyst cavity. Ethibloc injection was the primary treatment in five patients. Four patients had recurrence following previous curettage and bone grafting and one patient had not responded to injection into the lesion of autologous iliac crest bone marrow aspirate. Three patients needed a second injection. The median follow-up was 27 (6-60) months. RESULTS AND CONCLUSION: Symptoms were relieved in all patients. At imaging, seven patients had resolution of the lesion and three had partial response at the most recent follow-up. Complications consisted of a local transitory inflammatory reaction in two patients and an aseptic abscess in one patient. This relatively simple, minimally invasive procedure makes an operation unnecessary by stopping the expansion of the cyst and inducing endosteal new bone formation. This technique may be used as the primary management of aneurysmal bone cysts excluding spinal lesions.

Serial changes in serum vitamin K1, triglyceride, cholesterol, osteocalcin and 25-hydroxyvitamin D3 in patients after hip replacement for fractured neck of femur or osteoarthritis.

Serum vitamin K1 concentrations were measured at presentation (just before surgery) and then at weekly intervals for 3 weeks in two groups of elderly patients requiring either hemiarthroplasty for fractured neck of femur (FON, n = 13) or total hip replacement for osteoarthritis of the hip (OA, n = 16). In comparison with healthy elderly volunteers (n = 25), serum vitamin K1 concentrations were significantly lower in both groups at presentation, and fell significantly within 24 h after surgery to concentrations approaching non-detectable, subsequently returning to pre-operative values within 3 weeks. Serum vitamin K1 tended to be lower in the fracture group both before and after operation, although calculation of a vitamin K1-triglyceride ratio reduced the apparent difference as triglyceride concentrations were lower in the fracture group. Osteocalcin concentrations were similar and fell significantly after operation in both groups, returning to pre-operative levels within 7 days. No differences in the two forms of osteocalcin (carboxylated and undercarboxylated) were observed either before or after operation in either group. 25-Hydroxyvitamin D3 concentrations were not significantly different between the two groups at any time. Vitamin K1 status may be lower than desirable in certain groups of the elderly population, and supplementation should be considered as prophylactic therapy.

Low blood manganese levels in Liverpool children with Perthes' disease.

The aetiology of Perthes' disease of the hip, avascular necrosis of the head of the femur, is unknown. Children with the disease have a generalised abnormality of growth. A similar disproportionate growth is found in chicks given a diet deficient in manganese. In Liverpool, which has the highest incidence of Perthes' disease reported anywhere in the world, children with the disease were shown to have lower blood manganese levels than controls. This is evidence that manganese deficiency around the time of birth may be a cause of Perthes' disease, but the results require confirmation.