Reliability and efficiency of three methods of calculating migration percentage on radiographs for hip surveillance in children with cerebral palsy.

PURPOSE: Hip surveillance programmes for children with cerebral palsy (CP) utilize the migration percentage (MP) measurement to initiate referrals and recommend treatment. This study assesses the reliability and efficiency of three methods of MP measurement on anteroposterior (AP) pelvis radiographs. METHODS: A total of 20 AP pelvis radiographs (40 hips) of children with CP were measured by three raters on two occasions using three methods: digital measurement (DM) on a Picture Archiving and Communication System monitor, computer-aided measurement (CA) using a digital templating tool and mobile device application measurement (MA) using a freely available MP measurement tool. For each method, the time required to complete the MP measurement of both hips on each AP pelvis radiograph was measured. Intra-class correlation coefficient (ICC) was used to determine reliability, and analysis of variance was used to compare groups. RESULTS: All three methods of determining MP showed excellent inter-rater and intra-rater reliability (ICC 0.976 to 0.989). The mean absolute difference in MP measurement was not significant between trials for a single rater (DM 2.8%, CA 1.9%, MA 2.2%) or between raters (DM 3.6%, CA 2.9%, MA 3.6%). The mean time to complete MP measurement was significantly different between methods, with DM = 151 seconds, CA = 73 seconds and MA = 80 seconds. CONCLUSION: All three MP measurement methods were highly reliable with clinically acceptable measurement error. The time required to measure a hip surveillance radiograph can be reduced by approximately 50% by utilizing a computer-based or mobile application-based MP measurement tool.

The operative correction of symptomatic flat foot deformities in children: the relationship between static alignment and dynamic loading.

At our institution surgical correction of symptomatic flat foot deformities in children has been guided by a paradigm in which radiographs and pedobarography are used in the assessment of outcome following treatment. Retrospective review of children with symptomatic flat feet who had undergone surgical correction was performed to assess the outcome and establish the relationship between the static alignment and the dynamic loading of the foot. A total of 17 children (21 feet) were assessed before and after correction of soft-tissue contractures and lateral column lengthening, using standardised radiological and pedobarographic techniques for which normative data were available. We found significantly improved static segmental alignment of the foot, significantly improved mediolateral dimension foot loading, and worsened fore-aft foot loading, following surgical treatment. Only four significant associations were found between radiological measures of static segmental alignment and dynamic loading of the foot. Weakness of the plantar flexors of the ankle was a common post-operative finding. Surgeons should be judicious in the magnitude of lengthening of the plantar flexors that is undertaken and use techniques that minimise subsequent weakening of this muscle group.

Removal of deep extremity implants in children.

We have reviewed our experience of the removal of deep extremity orthopaedic implants in children to establish the nature, rate and risk of complications associated with this procedure. A retrospective review was performed of 801 children who had 1223 implants inserted and subsequently removed over a period of 17 years. Bivariate analysis of possible predictors including clinical factors, complications associated with implant insertion and indications for removal and the complications encountered at removal was performed. A logistical regression model was then constructed using those predictors which were significantly associated with surgical complications from the bivariate analyses. Odds ratios estimated in the logistical regression models were converted to risk ratios. The overall rate of complications after removal of the implant was 12.5% (100 complications in 801 patients), with 48 (6.0%) major and 52 (6.5%) minor. Children with a complication after insertion of the initial implant or with a non-elective indication for removal, a neuromuscular disease associated with a seizure disorder or a neuromuscular disease in those unable to walk, had a significantly greater chance of having a major complication after removal of the implant. Children with all four of these predictors were 14.6 times more likely to have a major complication.

Proximal focal femoral deficiency (PFFD): management options and controversies.

Proximal focal femoral deficiency (PFFD) is a rare congenital anomaly characterised by failure of normal development of the proximal femur and hip joint. Significant variability in the clinical presentation and degree of deficiency is common. Current management strategies aimed at improving functional ambulation are largely dependent on the degree of femoral shortening and the status of the hip and knee joint. Treatment of acetabular deficiency and proximal femoral deformity in cases of PFFD must be individualised. Reconstruction of the hip joint with pelvic and femoral osteotomies may be possible in mild cases of PFFD. Stability of the hip and knee joint must be achieved prior to consideration for limb lengthening strategies. Severe cases of PFFD may be beyond surgical correction and warrant alternative strategies such as rotationplasty or selective amputation to facilitate prosthetic fitting.

Early radiographic differentiation of infantile tibia vara from physiologic bowing using the femoral-tibial ratio.

SUMMARY: The authors hypothesized that the ratio of the femoral to tibial metaphyseal-diaphyseal angles (femoral-tibial ratio [FTR]) more accurately differentiates physiologic bowing from infantile tibial vara than the tibial metaphyseal-diaphyseal angle (TMDA). The purpose of this study was threefold: to determine the false-negative and false-positive error rate of the FTR and TMDA; to determine to the effect of rotation on the FTR and TMDA; and to determine the reliability of the FTR and TMDA measurements. An FTR < 1 resulted in a false-negative error rate of 10% and a false-positive error rate of 7%, whereas a TMDA > 13 degrees resulted in a false-negative error rate of 23% and a false-positive error rate of 10%. The difference between internal and external rotation was not significant for the FTR, whereas it was for the TMDA. The FTR was found to have good interobserver and intraobserver reliability (0.78 and 0.98, respectively).

Radiographic evaluation of bowed legs in children.

Radiographic screening is widely used to distinguish between Blount disease (infantile tibia vara) and physiologic bowing. Thirteen children with Blount disease, evaluated before 3 years of age, with initial radiographs showing no sign of Langenskiold changes, were compared with 50 children with physiologic bowing, also evaluated before 3 years of age with similar radiographic studies. Screening test accuracy was determined retrospectively for measurement of the mechanical axis, the tibial metaphyseal-diaphyseal angle (TDMA), and the epiphyseal-metaphyseal angle (EMA). A radiographic screening method combining the TMDA and the EMA, using cutoff values of 10 degrees and 20 degrees respectively, exhibited the best combination of sensitivity, specificity, and positive predictive value, correctly identifying all cases of Blount disease and 40 of 50 cases of physiologic bowing. Our data suggest that children between 1 and 3 years of age with TMDA <10 degrees, or TMDA > or =10 degrees and EMA < or =20 degrees, are at less risk for development of Blount disease. Children with TMDA > or =10 degrees and EMA >20 degrees are at greater risk for development of Blount disease and should be followed closely.

Surgical management of hallux valgus deformity in children with cerebral palsy.

Twenty-six cases of hallux valgus deformity, in 16 children with cerebral palsy, were managed with great toe metatarsophalangeal (MTP) arthrodesis. Mean age at the time of surgery was 16 years (range, 10 years and 11 months to 21 years and 11 months), and mean follow-up was 4 years and 11 months (range, 2 years and 1 month to 10 years). Significant improvement in the hallux valgus angle (preoperative, 36.3 degrees; follow-up, 9.6 degrees; p < 0.05), the intermetatarsal angle (preoperative, 12.3 degrees; follow-up, 8.4 degrees; p < 0.05), and lateral metatarsophalangeal angle (preoperative, 4.8 degrees; follow-up, 25.8 degrees; p < 0.05), were achieved and maintained after MTP arthrodesis. Functional outcome was documented by significant improvement in the modified American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal-Interphalangeal Scale (preoperative mean score, 46.2; follow-up mean score, 90.9; p < 0.05). Patient/ parent/caregiver satisfaction (as determined by a questionnaire), with improvements in cosmesis, footwear, hygiene, activity, and pain were high, ranging from 81% to 100%. Hallux valgus deformity in children with cerebral palsy is best managed by MTP arthrodesis, in conjunction with other surgical procedures that address segmental foot malalignment and dynamic gait deviations.

Management of lower extremity riding lawn mower injuries in children.

Eight children are injured by riding lawn mowers every day. The child, usually a bystander or passenger on the mower, can sustain life-threatening and limb-threatening injuries. Multidisciplinary care must be available to manage the numerous issues presented by the unique circumstance of a child with a severe injury in the acute and chronic settings. Whether the limb is salvaged or amputated, the ultimate goal is optimal functional outcome for the patient. We have developed a team approach to address these injuries from their onset until patient maturity, maximizing our ability to achieve this goal.

Wrist arthrodesis in children with cerebral palsy.

Wrist arthrodesis was performed on 19 upper extremities in 18 children with cerebral palsy to correct volar flexion and ulnar deviation deformities. Mean age at the time of surgery was 15.8 years, and mean follow-up was 4.7 years. Review of medical records and radiographs and follow-up clinical examination, including standardized functional testing and a child/parent questionnaire, were performed to assess outcome in technical, functional, and satisfaction domains. Technical domain outcomes were best when arthrodesis was performed by proximal row carpectomy with plate fixation. Functional improvement, as documented by the House scale, averaged 1.8 levels, with 14 children (83.3%) showing improvement. Child/parent satisfaction with cosmetic, hygienic, and functional outcomes was high, ranging from 72 to 94%. Wrist arthrodesis, when combined with appropriate procedures for the forearm, fingers, and thumb, provided excellent technical, functional, and satisfaction domain outcomes for children with cerebral palsy, particularly those with more severe upper extremity involvement, dyskinetic type cerebral palsy, or poor motivation for rehabilitation.

A biomechanical analysis of gait during pregnancy.

BACKGROUND: There are many anatomical changes during pregnancy that could potentially lead to substantial alterations in gait. Gait deviations may contribute to a variety of musculoskeletal overuse conditions associated with pregnancy, such as low-back, hip, and calf pain. Because we are aware of little research on this topic, the purpose of this study was to objectively analyze gait during pregnancy. METHODS: Three-dimensional gait analysis was performed on fifteen women during the second half of the last trimester of pregnancy and again one year post partum. Selected kinematic and kinetic parameters for the pregnancy and one-year postpartum conditions were compared with use of paired t tests (95 percent significance level). RESULTS: Overall, gait kinematics were remarkably unchanged during pregnancy. No evidence of a so-called waddling gait during pregnancy was found. Maximum anterior pelvic tilt during gait increased a mean of 4 degrees during pregnancy, although individual subject-to-subject variation (range, an increase of 13 degrees to a decrease of 10 degrees) was observed. Significant increases in hip and ankle kinetic gait parameters, however, were observed during pregnancy (p < 0.05). CONCLUSIONS: Significant increases in kinetic gait parameters during pregnancy (p < 0.05) explain how gait motion remained relatively unchanged despite increases in body mass and width as well as changes in mass distribution about the trunk. This finding indicates that during pregnancy there may be an increased demand placed on hip abductor, hip extensor, and ankle plantar flexor muscles during walking.

Clinical evaluation of bowed legs in children.

Early radiographic screening and/or referral to a clinical specialist are often used to distinguish between physiologic bow leg deformity and infantile tibia vara disease in young children. These practices are a consequence of the clinician's inability (based upon the clinical examination) to distinguish between the deformities associated with physiologic and pathologic bow legs. Because the great majority of these children have physiologic bowing, routine radiographic screening and referral are not cost effective and expose children to unnecessary radiation. This study describes and evaluates the efficacy of a simple clinical examination technique, the 'cover up' test, to identify young children with bow legs who are at high risk for having infantile tibia vara. The 'cover up' test qualitatively assesses the alignment of the proximal portion of the shank or lower leg relative to the thigh or upper leg. Obvious valgus alignment is considered a negative test and is indicative of physiologic bowing. Neutral or varus alignment is considered a positive test and suggests that the child is at greater risk for having infantile tibia vara. Eighteen children with infantile tibia vara, evaluated initially prior to 3 years of age, and followed to the time of surgical correction, were compared with 50 children with physiologic bowing, also evaluated initially prior to 3 years of age and followed to resolution (mean follow-up 3 years and 10 months). All of the children with infantile tibia vara had a positive 'cover up' test (sensitivity = 1.00). Eighteen of 25 children with a positive 'cover up' test actually had or developed infantile tibia vara (positive predictive value = 0.72). Forty-three of 50 children with physiologic bowing had a negative 'cover up' test (specificity = 0.86). All of the children with a negative 'cover up' test actually had physiologic bowing (negative predictive value = 1.00). We conclude that the 'cover up' test is an effective screening tool for the assessment of bow legs in children between 1 and 3 years of age. Children with a negative 'cover up' test do not require radiographic evaluation and should be followed clinically for resolution of the bowing. Children with a positive 'cover up' test should have radiographic evaluation of the lower extremities or be referred to a specialist for further evaluation and treatment.

Cubitus varus associated with dislocation of both the medial portion of the triceps and the ulnar nerve.

Five patients with cubitus varus deformities from malunited childhood fractures had dislocation (snapping) of both the medial portion of the triceps and the ulnar nerve over the medial epicondyle. In addition to snapping, these patients had medial elbow pain or ulnar nerve symptoms. Cubitus varus shifts the line of pull of the triceps more medial, which can cause anteromedial displacement of the medial portion of the triceps during elbow flexion. The ulnar nerve is concomitantly pushed or pulled anteromedially by the triceps, and ulnar neuropathy may result from friction neuritis or from dynamic compression by the triceps against the epicondyle. Recognition of both the dislocating ulnar nerve and the snapping medial triceps is crucial in the successful treatment of this pathologic finding. In symptomatic individuals, we recommend either corrective valgus osteotomy of the distal humerus or partial excision or lateral transposition of the snapping medial triceps, or a combination of both. Alternatively, medial epicondylectomy can also eliminate the snapping. Transposition of the ulnar nerve can be performed for ulnar nerve symptoms and/or ulnar nerve instability. Using this approach, correction of the snapping and/or ulnar nerve symptoms was achieved in all cases.

Voluntary (normal) versus obligatory (cerebral palsy) toe-walking in children: a kinematic, kinetic, and electromyographic analysis.

Surgical management of toe-walking gait in children with cerebral palsy currently favors simultaneous, multilevel soft-tissue and bony interventions. Formulation of such a surgical plan is based on our ability to determine which of the gait deviations present are primary and which are secondary or compensatory. To evaluate this issue further, 32 normal children, walking normally and voluntarily toe-walking, were compared to 15 children with cerebral palsy walking in an obligatory toe-walking gait pattern. Computer-based analysis of gait was performed for each child, including time-distance, kinematic, kinetic, and electromyographic analyses. Significant deviations common to both normal and cerebral palsy toe-walking groups were determined to be due, at least in part, to the biomechanical constraints associated with a toe-walking gait pattern. Deviations unique to the cerebral palsy group were thought to represent primary gait deviations related to the underlying injury to the central nervous system. This study identifies the need to develop more sophisticated techniques of data collection and analysis and supports the inclusion of more varied and demanding functional activities for distinguishing between primary and secondary gait deviations in children with cerebral palsy.

Objective assessment of dyskinesia in children with cerebral palsy.

The clinical classification of children with cerebral palsy is limited by multiple factors. Distinguishing between spasticity and dyskinesia is critical, because the outcome after standard orthopaedic and neurosurgical interventions is less predictable in children with cerebral palsy who have a significant dyskinetic component. This study applied computer-based analysis of gait to assess objectively the presence of significant dyskinesia in children with cerebral palsy. Three-dimensional gait analysis was performed on 18 normal children, 17 children with principally spastic cerebral palsy, and 23 children with significantly dyskinetic cerebral palsy. Children were assigned to the spastic or dyskinetic groups prospectively, based on clinical analysis by an experienced physician and physical therapist. The children with dyskinesia were found to have a significantly wider, and more variable normalized dynamic base of support, a smaller step profile (step length divided by step width), and a greater and more variable maximal lateral acceleration than the spastic and normal groups (mixed model analysis of variance, p = 0.0001). A predictive model of dyskinesia, (developed by logistic regression analysis), using these gait parameters, exhibited excellent sensitivity, correctly classifying 20 (87%) of 23 children as dyskinetic. This study shows that children with dyskinetic cerebral palsy have distinct gait parameters and that objective assessment of dyskinesia in children with cerebral palsy is possible with computer-based analysis of gait.

A survey of function in children with lower limb deficiencies.

Function and prosthesis technical problems were surveyed in 258 experienced paediatric lower-limb prosthesis wearers. The two-part survey form consisted of the modified Prosthesis Evaluation Scale and the core module of the American Academy of Orthopaedic Surgeons/Council of Musculoskeletal Specialty Societies (AAOS/COMSS) Lower Limb Outcomes instrument. Eighty-eight percent (88%) of these paediatric subjects were able to wear their prosthesis more than 9 hours/day; only 3 subjects (1%) were not able to wear their limb at all. The average distance walked per day was reported to be 5.24 kilometres. Sixteen percent (16%) reported pain as "moderate" or worse. A majority reported not having a problem with perspiration, however, 20% had problems serious enough to limit prosthesis wearing time significantly. The most common reasons for temporary loss of limb use were pain (62 responses) and prosthesis failure (59 responses), followed by tissue breakdown (42 responses) and perspiration (30 responses). In general, the paediatric population achieves full use at a high rate, is much more active than the adult population, and experiences less limb pain.

Kinematic and kinetic analysis of running in children with cerebral palsy.

Computer-based analysis of gait was used to study walking and running in 19 children with spastic-diplegic cerebral palsy (CP) and 15 healthy control children. Temporospatial parameters, kinematic and kinetic data were compared and contrasted between groups for both types of gait. The majority of children with diplegic CP, who are independent ambulators, are able to run. These children increase their velocity by increasing their cadence, a mechanism that is distinct (and presumably less energy efficient) from that used by healthy children. Sagittal-plane kinematic and kinetic profiles at the ankle in children with CP were more similar to normal profiles in running than in walking, suggesting that the primary deviations at the ankle associated with CP are better tolerated at greater velocities. Relative power analysis showed that, like healthy children, those with CP depend more upon the proximal musculature about the hip for power generation as the velocity of gait increases. Children with CP achieve energy transfer between adjacent joints during walking and running in a manner comparable to unaffected children. Running is an important activity for children and should be considered in the functional assessment of those with CP.

Proximal tibiofibular bifurcation synostosis for the management of longitudinal deficiency of the tibia.

Three adults with severe longitudinal deficiency of the tibia (LDT), in which an unossified proximal tibial anlage was present, who had been treated with proximal tibiofibular bifurcation synostosis (PTFBS) in early childhood, were evaluated between 20 and 31 years after the index procedure. All three were found to be functioning well as below-the-knee (BK) amputees. Mediolateral stability and anteroposterior instability of the knee were present in all cases. Instrumented motion analysis revealed diminished loading characteristics of the prosthetic limb, similar to that described for BK amputees in general. The most significant gait deviations at the knee unique to this study group were a quadriceps-avoidance gait pattern and an increased dynamic varus alignment. Instrumented muscle testing suggested that these deviations were a consequence of ligamentous instability. This study supports the concept that the presence of a proximal tibial anlage in severe LDT is indication for a surgical strategy that preserves the biological knee joint. The PTFBS maintains the integrity of the knee-extensor mechanism, the fibular collateral ligament, the tibiofemoral joint capsule, and the medial collateral ligament, enhancing the long-term stability and function of the knee joint.

Skin surface pressure beneath an above-the-knee cast: plaster casts compared with fiberglass casts.

Complications related to immobilization in a cast after an injury or an operation may be related to the materials used for the cast or to the techniques of application, or to both. To evaluate the widely held clinical opinion that the use of a fiberglass cast is dangerous and inappropriate when subsequent swelling of the extremity is anticipated, we studied the skin surface pressures that were generated beneath above-the-knee casts made with different materials and applied with different techniques. A prosthetic model of the lower extremity was designed with an expandable calf compartment to simulate swelling after an injury or an operation. With use of this model, we measured the skin surface pressure beneath a plaster-of-Paris cast, a fiberglass cast that had been applied with a standard technique, and a fiberglass cast that had been applied with a stretch-relax technique. The highest mean skin surface pressure after application of the cast (p < 0.001) and after simulated swelling of the limb (p = 0.04) was generated by the fiberglass cast that had been applied with a standard technique. The lowest mean skin surface pressure after application of the cast (p = 0.006), simulated swelling of the limb (p < 0.001), and all subsequent steps of the experimental protocol (p < 0.001) was generated by the fiberglass cast that had been applied with the stretch-relax technique. The mean skin surface pressure generated by the plaster cast and by the fiberglass cast applied with the standard technique did not return to the value before application of the cast until anterior and posterior longitudinal cuts had been made in the cast and the cast had been spread at those cuts. When the fiber-glass cast had been applied with the stretch-relax technique, the mean pressure returned to the baseline value after only an anterior longitudinal cut and spreading at that cut. The principal pitfall of the use of a fiberglass cast is related to the technique of application. When the fiberglass cast had been applied with the standard technique, it generated a mean skin surface pressure that was higher than that associated with the plaster cast and it accommodated simulated swelling poorly. When the fiberglass cast had been properly applied, with the stretch-relax technique, it generated a mean skin surface pressure that was significantly lower (p = 0.006) than that associated with the plaster cast and it better accommodated simulated swelling without the need to sacrifice the structural integrity of the cast.

Dislocating medial triceps and ulnar neuropathy in three generations of one family.

Variations in the medial triceps in conjunction with bilateral ulnar neuropathy have been identified in three generations of one family also possessing the phenotype of Waardenburg syndrome (a rare autosomal-dominant disorder with clinical features including cochlear deafness, dystopia canthorum, and pigmentation problems). To our knowledge, no other inherited condition with triceps anomalies has been reported. Study of this family provided insight into the relationship between dislocating medial triceps and ulnar neuropathy and demonstrated that a broad spectrum of clinical presentations exists-from being completely asymptomatic to producing symptomatic snapping and ulnar neuropathy.