John S. Blanco

Clinical evaluation of crossed-pin versus lateral-pin fixation in displaced supracondylar humerus fractures

The radiographs and patient charts of 47 children treated with closed reduction and percutaneous pin fixation of displaced supracondylar humerus fractures were reviewed. Twenty-seven fractures were fixed with crossed medial and lateral pins. Twenty fractures were treated with two parallel laterally placed pins. Baumanns angle on the anteroposterior elbow film and the humerocapitellar angle on the lateral elbow film were independently measured by the three authors on initial postoperative films and on films taken at the time of pin removal. No statistically significant differences regarding maintenance of reduction were found when comparing the two fixation groups. There were two complications in the medial pin group (one cubitus varus and one ulnar nerve injury) and none in the lateral-pin group. We conclude that crossed-pin fixation offers no clinically significant advantage over two laterally placed pins in the treatment of supracondylar humerus fractures.

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

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.

Ankle and Knee Coupling in Patients with Spastic Diplegia: Effects of Gastrocnemius-Soleus Lengthening

Background: Empirical observations of subjects with an equinus gait have suggested that there is coupled motion between the ankle and knee such that, during single-limb stance, the ankle moves into equinus as the knee extends. Since the gastrocnemius-soleus muscle-tendon unit spans both joints, we hypothesized that this muscle-tendon unit may be responsible for the coupling and that lengthening of the gastrocnemius-soleus muscle alone would result in greater ankle dorsiflexion as well as greater knee extension in single-limb stance, effectively uncoupling these joints. The concept that gastrocnemius-soleus lengthening may promote knee extension is counter to the popular notion that crouch gait may result if the hamstrings are not lengthened concomitantly. Methods: A retrospective review identified thirty-four subjects with specific kinematic characteristics of equinus gait, and their gait was compared with that of normal children. Of the thirty-four subjects, eleven (twenty-two limbs) subsequently underwent isolated midcalf lengthening of the gastrocnemius and soleus muscles with use of a recession technique. Gait analysis including joint kinematics and joint kinetics, electromyography, and physical examination were performed to test the hypothesis. Results: We found that, unlike the normal subjects, the patients with an equinus gait pattern had a positive correlation (r = 0.7) between ankle and knee motion during single-limb stance. As hypothesized, ankle plantar flexion occurred while the knee moved into extension during single-limb stance. Calculations of the lengths of the gastrocnemius-soleus muscle-tendon units showed them to be short throughout the gait cycle (p < 0.0001). After gastrocnemius-soleus recession, peak ankle dorsiflexion (p < 0.001) and peak ankle power (p < 0.001) shifted to occur later in stance than they did in the preoperative gait cycle. Furthermore, the magnitude of peak power increased (p < 0.001) in late stance despite the added length of the gastrocnemius-soleus muscle-tendon unit. The electromyographic amplitude of the gastrocnemius-soleus was reduced during loading (p < 0.02), and this finding, together with the kinetic changes, suggested that muscle tension was reduced. Changes at the knee were less pronounced but included greater knee extension at foot contact (p < 0.01). No increase in the knee flexion angle or extension moment occurred in midstance after the surgery. Conclusions: Patients with an equinus gait pattern function with a shortened gastrocnemius-soleus muscle-tendon unit, and this results in coupled motion between the ankle and knee during single-limb stance. Lengthening, with use of a recession technique, shifted ankle power generation and dorsiflexion to a later time in stance with no tendency to increase midstance knee flexion. Knee extension did increase at foot contact, but excessive midstance knee flexion persisted and was likely due to concomitant contracture of the hamstrings.

Comparison of single pin versus multiple pin fixation in treatment of slipped capital femoral epiphysis.

From January 1982 to December 1987, 114 hips of 80 patients underwent pinning for treatment of slipped capital femoral epiphysis (SCFE). Three groups were differentiated based on the number of pins used. The average length of follow-up was 2 years 5 months. The mean time to physeal closure was 5.43 months in the single pin group, 5.54 months in the two pin group, and 6.44 months in the three or more pin group. These differences were not statistically significant. There was a statistically significant decrease in the rate of pin-related complications and reoperations in the single pin group as compared with the two pin and multiple pin groups. We conclude that central single pin fixation for treatment of SCFE dependably results in physeal closure while minimizing pin-related complications.

Allograft bone use during instrumentation and fusion in the treatment of adolescent idiopathic scoliosis.

Study Design. In a retrospective study, 25 patients undergoing posterior spine fusion with allograft bone and Cotrel-Dubousset instrumentation were assessed regarding the efficacy of allograft bone use. Objectives. To determine if allograft bone use had deleterious effects regarding fusion rates and maintenance of deformity correction. Summary of Background Data. Previous studies using allograft bone in adult lumbar spine fusion models have consistently shown poor fusion rates. Studies in the pediatric population have been more favorable but in idiopathic cases have used cast or brace immobilization with Harrington instrumentation. Methods. Twenty-five skeletally immature patients with an average age of 14 ± 4 years and an average follow-up of 4 ± 2 years (minimum of 3 years) were evaluated with anteroposterior, lateral, and oblique radiographs to assess the fusion mass. Results. Preoperative curves averaged 55.5° and immediate correction averaged 58% with an average postoperative curve of 23.2°. Loss of correction at final follow-up was 3.7°. No pseudarthroses were identified clinically or radiographically. Conclusions. Allograft bone use in the pediatric patient with idiopathic scoliosis undergoing rigid segmental instrumentation dependably results in fusion with good maintenance of correction.

Medial and lateral pin versus lateral-entry pin fixation for Type 3 supracondylar fractures in children: a prospective, surgeon-randomized study.

Background The purpose of this study is to compare the efficacy of medial and lateral (crossed pin) and lateral-entry pin techniques for Gartland Type 3 supracondylar humerus fractures in children. Methods Six pediatric orthopaedists were divided into the 2 treatment groups (medial and lateral pins or lateral only pins) based on pre-study pinning technique preferences. Patients were randomized into 1 of the 2 pinning technique treatment groups based on which attending was on call at the time of patient presentation. One hundred and four patients met inclusion criteria. Forty-seven patients underwent lateral-entry pinning and 57 underwent crossed pinning. The 2 groups were similar with respect to age, sex, preoperative neurovascular injury, direction of fracture displacement, and timing of surgery. Outcome parameters measured included radiographic maintenance of reduction, iatrogenic neurovascular complications, and rate of infection. All radiographic measurements, and interobserver reliability, were determined by a 3 physician panel. Results The results of the interobserver reliability data showed a strong correlation and this data allowed 95% confidence that a change in Baumanns angle of more than 6 degrees and humerocapitellar angle of more than 10 degrees was significant. The lateral-entry patients experienced a median absolute change of Baumanns angle of 3.7 degrees with 12 patients having greater than 6 degrees loss of reduction; whereas those in the medial and lateral-pin group saw a median change of 2.9 degrees with 10 patients having greater than 6 degrees loss of reduction. In terms of the humerocapitellar angle, the lateral-entry patients experienced a median absolute change of 4.8 degrees with 11 patients having greater than 10 degrees loss of reduction; whereas those in the medial and lateral-pin groups saw a median change of 5.1 degrees with 17 patients having greater than 10 degrees loss of reduction. There was no significant difference in infection rate between the 2 groups but 2 cases of iatrogenic neurovascular injury occurred in patients who had a medial pin placed. Conclusions We found no statistical difference in the radiographic outcomes between lateral-entry and medial and lateral-pin techniques for the management of Type 3 supracondylar fractures in children when evaluated in this prospective and surgeon-randomized trial, but 2 cases of iatrogenic injury to the ulnar nerve occurred with medially placed pins. Level of Evidence Level 2.

Asymmetric hip deformity and subluxation in cerebral palsy: an analysis of surgical treatment.

Thirty-seven cerebral palsy patients were followed with measurements of the migration index (MI), infrapelvic obliquity, and suprapelvic obliquity over a mean period of 73 months to evaluate the development of the windblown deformity. The infrapelvic asymmetry was apparent before the suprapelvic obliquity; however, 65% eventually had both. The final pattern of infrapelvic obliquity and the most subluxed hip could not be predicted from initial radiographs or from the pattern of scoliosis. Hip subluxation strongly correlated with the degree of femoral adduction and weakly with the magnitude of suprapelvic obliquity. The suprapelvic obliquity and scoliosis increased over time and influenced the final windblown appearance. Soft-tissue surgeries did not have a significant effect on the final MI. Severe abduction deformities generally followed ipsilateral adductor releases. Finally, despite improvement in the MI of the initially more subluxed hip, 33% of patients still had one hip with a MI >50%.

Allograft Bone in Spinal Fusion for Adolescent Idiopathic Scoliosis

Objective: The purpose of this long-term study was to determine the efficacy of allograft bone for spinal fusion for adolescent idiopathic scoliosis. Prior studies comparing allograft and autograft have been short term. Methods: This multicenter retrospective study was carried out on 111 patients with 132 total curves fused for adolescent idiopathic scoliosis. Minimum follow-up was 5 years (average 72 months). A variety of segmental instrumentation was used, with most being dual-rod, multiple-hook constructs. Results: Average preoperative curve was 59° with immediate correction to 29° (51%) and final follow-up of 32.24° (45.4%). Average loss of correction was 3.5° (5.9%). There were three pseudarthroses, one infection, and no rod breakage. Conclusion: Pseudarthrosis rate of 2.7% and loss of correction of 5.9% are comparable with or better than those in previous reports using autogenous bone graft and either segmental or nonsegmental instrumentation.

Update on the management of idiopathic scoliosis.

Purpose of review Idiopathic scoliosis is a lateral curvature of the spine greater than 10° for which there is no known cause. This paper reviews the current literature on the appropriate evaluation and treatment of patients with idiopathic scoliosis. Recent findings Improved technology and surgical techniques are allowing improved curve correction and improved quality of life for these patients. Specifically, the pedicle screw construct can provide excellent curve correction and stabilization for spinal deformities. Summary Idiopathic scoliosis is a diagnosis of exclusion and the approach to a patient with scoliosis should aim toward ruling out other possible causes. In those patients with scoliosis necessitating treatment, bracing should be the first line of treatment and these patients should be followed up closely to track curve progression. Patients who fail conservative management may undergo spinal fusion with pedicle screw instrumentation. Vigilant monitoring and thorough evaluation of scoliosis patients can steer patients toward appropriate management in a judicious manner preventing the significant medical morbidity and deformity that scoliosis can insidiously inflict.

Posterior-only unit rod instrumentation and fusion for neuromuscular scoliosis.

Study Design. A retrospective study to determine the efficacy of posterior-only unit rod instrumentation and fusion in a skeletally immature neuromuscular scoliosis population. Objective. To determine whether the posterior-only approach to this population adequately addresses the concerns of correction of scoliosis and pelvic obliquity, maintenance of that correction over time, and the incidence of crankshaft phenomenon. Summary of Background Data. Controversy exists regarding the need for anterior release to improve curve flexibility and the need to obtain an anterior arthrodesis in those skeletally immature patients at risk for crankshafting with continued anterior growth. Methods. From 1992 through 1997, 28 consecutive skeletally immature patients with neuromuscular scoliosis underwent posterior-only unit rod instrumentation and fusion for the treatment of progressive, symptomatic spinal deformities. Preoperative, immediate postoperative, and final follow-up radiographs were analyzed with respect to scoliosis and pelvic obliquity correction, maintenance of that correction over time, and the development of the crankshaft phenomenon as evidenced by loss of correction and/or increased rib–vertebral angle difference. The average age of the patients was 12.8 years and the average follow-up was 58 months with a minimum of 2 years. Results. Twenty-six patients were available for final follow-up. The initial Cobb angle correction averaged 66%, with 75% of the pelvic obliquity corrected. These corrections were maintained over time. Before surgery 27 of 28 patients were Risser 0, 1, or 2. The triradiate cartilage was open in nine patients, and five patients were ≤10 years of age. At the final follow-up 22 of the 26 patients were Risser 5 and 4 were Risser 4. There was one patient with increased rib–vertebral angle difference over the length of follow-up, with no loss of frontal or sagittal plane alignment. Conclusions. These results indicate that even in the very young neuromuscular patient, acceptable amounts of curve correction can be achieved and maintained with posterior-only unit rod instrumentation and fusion. The biomechanical stiffness of this construct seemed to be able to prevent the crankshaft phenomenon in the majority of those patients at risk.