Deirdre D. Ryan

Results of tibial rotational osteotomy without concomitant fibular osteotomy in children with cerebral palsy

A retrospective review was performed of 46 consecutive ambulatory children with cerebral palsy and tibial torsion who underwent 72 distal tibial derotational osteotomies without concomitant fibular osteotomy. The average amount of derotation measured at surgery was 21 ± 5 degrees. The average change in thigh-foot angle at follow-up was 21 ± 9 degrees. There were eight perioperative complications (11%): three delayed unions, three superficial wound dehiscences, one case of osteomyelitis, and one superficial pin tract infection. There were no incidences of malunion or nonunion. Preoperative and postoperative three-dimensional gait analysis data were used to determine the effect of distal tibial osteotomy on foot progression angle in seven subjects (11 limbs). Foot progression improved significantly. This study shows that distal tibial osteotomy alone (without concomitant fibular osteotomy) is an effective and safe procedure for correcting and maintaining correction of tibial torsion in patients with cerebral palsy.

Iatrogenic nerve injuries in the treatment of supracondylar humerus fractures: are we really just missing nerve injuries on preoperative examination?

Background: Recent studies report the rate of iatrogenic nerve injury in operatively treated supracondylar humerus (SCH) fractures is 3% to 4%. A reliable neurological examination can be difficult to obtain in a young child in pain. We hypothesized that nerve injuries may be missed preoperatively, later noted postoperatively in a more compliant patient, and then falsely considered an iatrogenic injury. Methods: A prospective study was conducted on patients who presented between April 2011 and April 2013 with an extension-type SCH fracture that was managed surgically. A neurological examination was performed preoperatively, postoperatively, and at follow-up visits by a fellowship-trained attending pediatric orthopaedic surgeon. Only patients in whom the attending surgeon felt a reliable neurovascular examination was obtained were included in this study. Results: Of the 100 patients, 16% had a nerve injury recognized on preoperative examination and 3% had a new nerve injury on postoperative examination (1 anterior interosseous, 1 median sensory, and 1 radial motor). The Gartland type (P=0.421), type of reduction (open vs. closed; P=0.720), and number of lateral-entry (P=0.898) or medial-entry (P=0.938) pins used were not associated with patients who had a new nerve injury found postoperatively. A trend was seen between fracture severity and rate of a preoperative nerve injury: type II 7% (2/28), type III 19% (9/58), and type IV 36% (5/14) (P=0.058). Preoperatively, nerve injuries were noted at the following rates: median 12% (12/100) (including 8 anterior interosseous nerve injuries), radial 8% (8/100), ulnar 3% (3/100). Conclusions: In this prospective study, in patients who were able to comply with a preoperative neurological examination done by an attending pediatric orthopaedic surgeon, the rate of iatrogenic nerve injury after operative treatment of SCH fractures is 3%. We conclude that this finding is true, and not a result of inadequate preoperative neurological examinations. Level of Evidence: Level I prognostic study.

Increased Incidence of Sacroiliac Joint Infection At a Children's Hospital

Background Pyogenic sacroiliitis (PSI) is an uncommon type of osteoarticular infection. A study is undertaken to confirm an observed increase in incidence of PSI at our pediatric institution and to evaluate any associations with increasing incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection and other factors. Methods All inpatients with osteoarticular infection were identified from the periods of 1992 to 1996 and 2004 to 2007. Patients with surgical site infection, immunologic deficits, decubiti, or other predisposing factors were excluded. Demographic, microbiologic, and clinical factors were analyzed for comparison. Results Overall 362 cases were included: 205 with osteomyelitis alone and 157 with pyarthrosis, of which 15 were PSI cases. The incidence of PSI increased from the periods of 1992 to 1996 and 2004 to 2007 (0.8 vs. 2.8 cases/y, P=0.03), along with osteomyelitis at pelvic and spinal sites (ie, axial sites; 1.6 vs. 5.0 cases/y; P=0.03), whereas the incidence of osteoarticular infection at other sites remained stable. CA-MRSA was isolated in 1 (6.7%) PSI case. In the second time period, CA-MRSA did not form a higher proportion of S. aureus isolates at sacroiliac or other axial sites (CA-MRSA: 17% of S. aureus in PSI and axial osteomyelitis vs. 45% of S. aureus at nonaxial sites, P=0.08). Patients were older in the second time period (4.5 y vs. 7 y; P<0.0001), and patients with PSI (10.5 y) and axial osteomyelitis (8.5 y) were older than those with osteoarticular infection at other sites (5.3 y; P<0.0001). Conclusions The emergence of CA-MRSA does not explain the increasing incidence of PSI. The incidence of PSI and osteomyelitis involving the axial skeleton are increasing, predominantly in older patients. These trends should be prospectively investigated. Level of Evidence III, Prognostic Study.

Differences in implementation of gait analysis recommendations based on affiliation with a gait laboratory

This study examined the extent to which gait analysis recommendations are followed by orthopedic surgeons with varying degrees of affiliation with the gait laboratory. Surgical data were retrospectively examined for 95 patients with cerebral palsy who underwent lower extremity orthopedic surgery following gait analysis. Thirty-three patients were referred by two surgeons directly affiliated with the gait laboratory (direct affiliation), 44 were referred by five surgeons from the same institution but not directly affiliated with the gait laboratory (institutional affiliation), and 18 were referred by 10 surgeons from other institutions (no affiliation). Data on specific surgeries were collected from the gait analysis referral, gait analysis report, and operative notes. Adherence to the gait analysis recommendations was calculated by dividing the number of procedures where the surgery followed the gait analysis recommendation (numerator) by the total number of procedures initially planned, recommended by gait analysis, or done (denominator). Adherence with the gait analysis recommendations was 97%, 94%, and 77% for the direct, institutional, and no affiliation groups, respectively. Procedures recommended for additions to the surgical plan were added 98%, 87%, and 77% of the time. Procedures recommended for elimination were dropped 100%, 89%, and 88% of the time. Of 81 patients who had specific surgical plans prior to gait analysis, changes were implemented in 84% (68/81) following gait analysis recommendations. Gait analysis influences the treatment decisions of surgeons regardless of affiliation with the gait laboratory, although the influence is stronger for surgeons who practice within the same institution as the gait laboratory.

A line drawn along the radial shaft misses the capitellum in 16% of radiographs of normal elbows.

Background: The radiocapitellar line (RCL) is a routinely referenced radiographic measurement for evaluating injury of the pediatric elbow, such as a Monteggia fracture. It is most commonly described as a line drawn along the radius that should intercept the center of the capitellum in a normal elbow. However, the RCL has not been rigorously defined or validated in young children. Methods: The RCL was drawn out on the anteroposterior and lateral radiographs of 116 normal pediatric elbows by 3 examiners. On each radiograph, lines were drawn along the longitudinal center of the radial neck as well as the radial shaft. The distance from each of these lines to the center of the capitellum was defined as the line-capitellar distance (LCD). The LCD was standardized to the patient size and correlated with patient variables. Results: Of the 2052 RCLs drawn, 50% (1029/2052) fell outside the middle third of the capitellum and 8.6% (176/2052) missed the capitellum completely. Lines drawn along the radial neck in the anteroposterior and lateral views missed the capitellum less frequently (1.2% vs. 12.7%, P<0.0001) and passed through its central third less (77.8% vs. 44.7%, P<0.0001) when compared with lines drawn using the radial shaft. Lines along the radial neck intersected the capitellum significantly more often on the lateral view than on the anteroposterior view (98.8% vs. 96.8%, P=0.06) and were more likely to pass through the center third of the capitellum (77.8% vs. 55.5%, P<0.0001). With both techniques of drawing the RCL, the percent of measurements falling within the middle third of the capitellum was higher in patients above 5 years of age (P<0.001). The RCL is more reliable in older patients and shows considerable variation in infants. Conclusions: The RCL does not invariably bisect or fall within the middle third of the capitellum in normal pediatric elbows. Therefore, an abnormal RCL is suggestive but not pathognomonic for injury such as Monteggia fracture. An RCL drawn along the radial shaft will miss the capitellum in 15.6% of elbows. The most consistent RCL is drawn along the radial neck on the lateral view. Patient variables such as age and sex should be considered in the ability of the RCL to identify elbow injury. Level of Evidence: Diagnostic Level 3.

Fat distribution in children and adolescents with myelomeningocele.

To evaluate fat distribution in children and adolescents with myelomeningocele using dual‐energy X‐ray absorptiometry (DXA).

Heterogeneity of muscle fat infiltration in children with spina bifida.

Children with spina bifida have well recognized functional deficits of muscle, but little is known about the associated changes in muscle anatomy and composition. This study used water-fat magnetic resonance imaging (MRI) to measure fat infiltration in the lower extremity muscles of 11 children with myelomeningocele, the most severe form of spina bifida. MRI measurements of muscle fat fraction (FF) were compared against manual muscle test (MMT) scores for muscle strength. The FF measurements were objective and reliable with mean inter-rater differences of <2% and intraclass correlation coefficients>0.98. There was a significant inverse relationship between muscle FF and MMT scores (P ≤ 0.001). Surprisingly, however, muscles with negligible strength (MMT 0-1) exhibited a bimodal distribution of FF with one group having FF>70% and another group having FF<20%. The MRI also revealed striking heterogeneity amongst individual muscles in the same muscle group (e.g., 4% fat in one participants lateral gastrocnemius vs. 88% in her medial gastrocnemius), as well as significant asymmetry in FF in one participant with asymmetric strength and sensation. These results suggest that quantitative water-fat MRI may serve as a biomarker for muscle degeneration which may reveal subclinical changes useful for predicting functional potential and prognosis.

Walking activity during daily living in children with myelomeningocele

Abstract Purpose: To quantify the walking activity of children with myelomeningocele during daily living. Method: Walking activity was measured using a StepWatch activity monitor over one week in 47 children with myelomeningocele (27 males; 9 years 11 months SD 2 years 7 months; 18 sacral, 9 low lumbar, 20 mid-high lumbar) and seven children with typical development (5 males; 11 years 1 month SD 1 year 11 months) in a prospective, cross-sectional study. Average total steps per day, number of steps and minutes spent at low, medium and high intensity stepping were evaluated. Groups were compared using t-tests and chi-squared tests with Bonferroni post-hoc adjustment. Results: Children with sacral and low lumbar myelomeningocele exhibited no significant differences in demographic characteristics or walking performance compared to typically developing children. Children with mid-high lumbar myelomeningocele exhibited higher BMI percentile than the control group (p = 0.04) and took fewer total steps per day than all other groups (p ≤ 0.04). Children with mid-high lumbar myelomeningocele also spent significantly less time taking steps at all intensity levels, particularly medium-intensity, than the sacral and low lumbar groups (p ≤ 0.04). Conclusions: Children with sacral and low lumbar myelomeningocele had walking performance similar to typically developing children despite a common need for braces and assistive devices. Children with mid-high lumbar myelomeningocele were less active, which may lead to heightened risk for secondary health conditions in addition to those associated with myelomeningocele. Implications for Rehabilitation Obesity, muscle weakening and disuse osteoporosis are issues for those with myelomeningocele, all of which are affected by walking activity. Understanding walking activity and intensity in children and adolescents with myelomeningocele may aid in developing focused rehabilitation interventions and strategies. Real world walking activity as an objective and quantified measure has the potential to help guide therapists and surgeons to more effective treatments.

Variability of the Anterior Humeral Line in Normal Pediatric Elbows.

Background: The anterior humeral line (AHL) is considered a valuable radiographic tool in the assessment of pediatric elbow sagittal plane alignment following injury. However, few studies exist that examine the validity of the AHL. The purpose of this study is to report the variability of the AHL in skeletally immature children with normal elbows. Methods: A total of 124 true lateral elbow radiographs of normal pediatric elbows were retrospectively identified and examined for the relationship of the AHL to the capitellum. The percentage of AHLs falling outside the middle third of the capitellum was compared among different age and sex groups using Fisher exact tests. Results: In 100% of patients, the AHL touched the ossific nucleus of the capitellum. In 100% (52/52) of patients ≥5 years the AHL goes through the middle third of the capitellum, but this is significantly different from patients less than 5 years of age in whom 25% (18/72) of patients the AHL fell outside of the middle third of the capitellum (P<0.001). In children less than 2 years of age, the AHL was in the anterior third in 30% of the cases. Conclusions: Traditional teaching that the AHL touches the capitellum on a lateral radiograph of a normal elbow in a child is correct, so if the AHL does not touch the capitellum it is appropriate to look for pathology. Similarly, in children 5 years and older the AHL goes through the middle third of the capitellum in all patients, so if it does not, it is appropriate to look for pathology. However, with decreasing age variability increases, with the AHL touching the anterior third of the capitellum in almost 1/3 of children. Level of Evidence: Level III.

Quantitative Analysis of Lower Leg Adipose Tissue Distribution in Youth with Myelomeningocele.

Children with myelomeningocele have a high prevalence of obesity and excess fat accumulation in their lower extremities. However, it is not known if this is subcutaneous or intramuscular fat, the latter of which has been associated with insulin resistance and metabolic disorders. This study quantified lower leg bone, muscle, and adipose tissue volume in children with myelomeningocele, classifying adipose as subcutaneous or muscle-associated. Eighty-eight children with myelomeningocele and 113 children without myelomeningocele underwent lower leg computed tomographic scans. Subcutaneous and muscle-associated adipose were classified based on location relative to the crural fascia. No differences were seen in subcutaneous adipose. Higher level disease severity was associated with increased muscle-associated adipose volume and decreased muscle volume. Bone volume tended to decrease with higher levels of involvement. Increases in lower leg adiposity in children with myelomeningocele are primarily attributable to accumulation of muscle-associated adipose, which may signify increased risk for metabolic disorders.