David L. Skaggs

Complications of growing-rod treatment for early-onset scoliosis: analysis of one hundred and forty patients.

BACKGROUND Previous reports have indicated high complication rates associated with non-fusion surgery in patients with early-onset scoliosis. This study was performed to evaluate the clinical and radiographic complications associated with growing-rod treatment. METHODS Data from the multicenter Growing Spine Study Group database were evaluated. Inclusion criteria were growing-rod treatment for early-onset scoliosis and a minimum of two years of follow-up. Patients were divided into treatment groups according to rod type (single or dual) and rod location (subcutaneous or submuscular). Complications were categorized as wound, implant, alignment, and general (surgical or medical). Surgical procedures were classified as planned and unplanned. RESULTS Between 1987 and 2005, 140 patients met the inclusion criteria and underwent a total of 897 growing-rod procedures. The mean age at the initial surgery was six years, and the mean duration of follow-up was five years. Eighty-one (58%) of the 140 patients had a minimum of one complication. Nineteen (27%) of the seventy-one patients with a single rod had unplanned procedures because of implant complications, compared with seven (10%) of the sixty-nine patients with dual rods (p ≤ 0.05). Thirteen (26%) of the fifty-one patients with subcutaneous rod placement had wound complications compared with nine of the eighty-eight patients (10%) with submuscular rod placement (p ≤ 0.05). The patients with subcutaneous dual rods had more wound complications, more prominent implants, and more unplanned surgical procedures than did those with submuscular dual rods (p ≤ 0.05). The risk of complications occurring during the treatment period decreased by 13% for each year of increased patient age at the initiation of treatment. The complication risk increased by 24% for each additional surgical procedure performed. CONCLUSIONS Regardless of treatment modality, the management of early-onset scoliosis is prolonged; therefore, complications are frequent and should be expected. Complications can be reduced by delaying initial implantation of the growing rods if possible, using dual rods, and limiting the number of lengthening procedures. Submuscular placement reduces wound and implant-prominence complications and reduces the number of unplanned operations.

Supracondylar Humeral Fractures in Children

Operative fixation is indicated for most type-II and III supracondylar humeral fractures in order to prevent malunion. Medial comminution is a subtle finding that, if treated nonoperatively, is likely to lead to unacceptable varus malunion. Angiography is not indicated for a pulseless limb, as it delays fracture reduction, which usually corrects the vascular problem. A high index of suspicion is necessary to avoid missing an impending compartment syndrome, especially when there is a concomitant forearm fracture or when there is a median nerve injury, which may mask symptoms of compartment syndrome. Lateral entry pins have been shown, in biomechanical and clinical studies, to be as stable as cross pinning if they are well spaced at the fracture line, and they are not associated with the risk of iatrogenic ulnar nerve injury.

Regional variation in tensile properties and biochemical composition of the human lumbar anulus fibrosus.

Study Design The structure-function relationship of anulus fibrosus of nondegenerate lumba intervertebral discs was investigated. Objectives The tensile properties and biochemical composition of single lamella specimens from human anulus librosus and their variations with anatomic region were determined. Summery of Background Data Regional differences in composition and ultrastructure suggest differences in tensile properties. Methods Single lamella specimens were isolated from the anulus, equilibrated in 0.15 ± NaCl and tested in uniaxial tension using a slow strain-rate protocol. Adjacent specimens were used to determine biochemical composition (Including nycration, collagen, proteonlycan, and hydroxypyridinium crosslink density). Tensile properties, biochemical composition, and anatomic location were compared. Results Significant radial and circumferential variations in tensile properties of anulus were detected, with the anterior being, stiffer than the posterolateral regions, and the outer being stiffer than the inner regions. Conclusions The regional differences in tensile properties may result predominantly from structural rather than compositional variations and may contribute to the clinical frequency of anulus failure in the postarolateral region.

Operative treatment of supracondylar fractures of the humerus in children. The consequences of pin placement

Background: The commonly accepted treatment of displaced supracondylar fractures of the humerus in children is fracture reduction and percutaneous pin fixation; however, there is controversy about the optimal placement of the pins. A crossed‐pin configuration is believed to be mechanically more stable than lateral pins alone; however, the ulnar nerve can be injured with the use of a medial pin. It has not been proved that the added stability of a medial pin is clinically necessary since, in young children, pin fixation is always augmented with immobilization in a splint or cast. Methods: We retrospectively reviewed the results of reduction and Kirschner wire fixation of 345 extension-type supracondylar fractures in children. Maintenance of fracture reduction and evidence of ulnar nerve injury were evaluated in relation to pin configuration and fracture pattern. Of 141 children who had a Gartland type-2 fracture (a partially intact posterior cortex), seventy‐four were treated with lateral pins only and sixty-seven were treated with crossed pins. Of 204 children who had a Gartland type-3 (unstable) fracture, fifty‐one were treated with lateral pins only and 153 were treated with crossed pins. Results: There was no difference with regard to maintenance of fracture reduction, as seen on anteroposterior and lateral radiographs, between the crossed pins and the lateral pins. The configuration of the pins did not affect the maintenance of reduction of either the Gartland type-2 fractures or the Gartland type-3 fractures. Ulnar nerve injury was not seen in the 125 patients in whom only lateral pins were used. The use of a medial pin was associated with ulnar nerve injury in 4% (six) of 149 patients in whom the pin was applied without hyperflexion of the elbow and in 15% (eleven) of seventy‐one in whom the medial pin was applied with the elbow hyperflexed. Two years after the pinning, one of the seventeen children with ulnar nerve injury had persistent motor weakness and a sensory deficit. Conclusions: Fixation with only lateral pins is safe and effective for both Gartland type-2 and Gartland type-3 (unstable) supracondylar fractures of the humerus in children. The use of only lateral pins prevents iatrogenic injury to the ulnar nerve. On the basis of our findings, we do not recommend the routine use of crossed pins in the treatment of supracondylar fractures of the humerus in children. If a medial pin is used, the elbow should not be hyperflexed during its insertion.

Increased Body Weight and Decreased Radial Cross‐Sectional Dimensions in Girls with Forearm Fractures

A large number of children sustain fractures after relatively minor trauma and several investigators have associated these fractures to a deficient accumulation of bone during growth. This study was conducted to better characterize the skeletal phenotype associated with low‐energy impact fractures of the forearm in girls. The densities of cancellous, cortical, and integral bone and the cross‐sectional area were measured in the radius of 100 healthy white girls (aged 4‐15 years) using computed tomography (CT); 50 girls had never fractured and 50 girls had sustained a forearm fracture within the previous month. Fractured and nonfractured groups were matched for age, height, weight, and Tanner stage of sexual development. Compared with controls, girls with fractures had, on average, 8% smaller cross‐sectional area at the distal radius (1.82 ± 0.50 cm2 vs. 1.97 ± 0.42 cm2; p < 0.0001) but similar cancellous, integral, and cortical bone densities. Neither radial length nor the amount of fat or muscle at the midshaft of the radius differed between girls with and without fractures. Both study subjects and matched controls were overweight. Although mean height was at the 50th percentile, mean weight was at the 90th percentile for age‐adjusted normal values. Girls who sustain forearm fractures after minor trauma have small cross‐sectional dimensions of the radius and tend to be overweight. The smaller cross‐sectional area confers a biomechanical disadvantage that, coupled with the greater body weight, increases the vulnerability to fracture after a fall.

Lateral-entry pin fixation in the management of supracondylar fractures in children.

BACKGROUND There has been controversy regarding the optimal pin configuration in the management of supracondylar humeral fractures in children. A crossed-pin configuration may be mechanically more stable than lateral pins in torsional loading, but it is associated with a risk of iatrogenic injury to the ulnar nerve. Previous clinical studies have suggested that lateral pins provide sufficient fixation of unstable supracondylar fractures. However, these studies were retrospective and subject to patient-selection bias. METHODS A displaced supracondylar humeral fracture was fixed with only lateral-entry pins in 124 consecutively managed children. Medical records and radiographs were reviewed to identify any complications, including loss of fracture reduction, iatrogenic ulnar nerve injury, infection, loss of motion of the elbow, and the need for additional surgery. In addition, eight displaced supracondylar humeral fractures that had been reduced and fixed with lateral pins at other institutions and had lost reduction were analyzed to determine the causes of the failures. RESULTS Sixty-nine children had a type-2 fracture, according to Wilkinss modification of Gartlands classification system; forty-three (62%) of those fractures were stabilized with two pins and twenty-six (38%), with three pins. Fifty-five children had a type-3 fracture; nineteen (35%) of those fractures were stabilized with two pins and thirty-six (65%), with three pins. A comparison of perioperative and final radiographs showed no loss of reduction of any fracture. There was also no clinically evident cubitus varus, hyperextension, or loss of motion. There were no iatrogenic nerve palsies, and no patient required additional surgery. One patient had a pin-track infection. Our analysis of the eight clinical and radiographic failures of lateral pin fixation that were not part of the consecutive series showed that the loss of fixation was due to fundamental technical errors. CONCLUSIONS In this large, consecutive series without selection bias, the use of lateral-entry pins alone was effective for even the most unstable supracondylar humeral fractures. There were no iatrogenic ulnar nerve injuries, and no reduction was lost. The important technical points for fixation with lateral-entry pins are (1) maximize separation of the pins at the fracture site, (2) engage the medial and lateral columns proximal to the fracture, (3) engage sufficient bone in both the proximal segment and the distal fragment, and (4) maintain a low threshold for use of a third lateral-entry pin if there is concern about fracture stability or the location of the first two pins.

Complications of posterior iliac crest bone grafting in spine surgery in children.

Study Design. The perioperative and postoperative complications associated with harvesting posterior iliac crest bone graft in children were reviewed. A retrospective study was performed and a questionnaire interview conducted. Objectives. To determine the morbidity associated with posterior iliac crest bone graft in children. Summary of Background Data. Iliac crest bone is commonly used as a source of bone graft in spine surgery. Although there are multiple reports of complications in adults, there are no reports in children. Methods. A retrospective chart review was performed of 214 consecutive children who underwent spinal fusion with posterior iliac crest bone graft from 1990 through 1996. An interview was conducted of 87 patients with normal mental status, predominantly those with idiopathic scoliosis with a minimum of 2 years’ follow-up (mean, 55 months). Results. The review showed one (0.5%) instance of arterial injury in the sciatic notch. Two (1%) patients had infections, both of which resolved with a single irrigation and débridement. There was one documented instance of sacroiliac penetration that did not cause clinical problems. The chart review showed three (1.4%) instances of continued pain and one (0.5%) of numbness. By contrast to the few reports of pain in the chart review, responses to an interview of 87 patients showed 21 (24%) children reporting pain at the iliac crest site, with 13 (15%) reporting problems with daily activities. The self-reported pain, on a scale of 1 to 10, ranged from 1 to 10 with a mean of 4. Nonsteroidal anti-inflammatory drugs (NSAIDS) were taken by eight (9%) children for pain at the bone graft site. Five (6%) reported skin irritation, and 18 (20%) mentioned numbness surrounding the scar. Conclusion. The perioperative rate of complications in iliac crest bone grafting in children is low (2%). The complication of pain (24%) and pain that is severe enough to interfere with daily activity (15%) is significant at a mean follow-up of more than 4 years. The true extent of pain and numbness after posterior iliac crest bone grafting in children was severely underreported in the medical records and may be underrecognized.

The effect of surgical delay on acute infection following 554 open fractures in children.

BACKGROUND Traditional recommendations hold that open fractures in both children and adults require urgent surgical debridement for a number of reasons, including the preservation of soft-tissue viability and vascular status as well as the prevention of infection. Following the widespread use of early administration of antibiotics, a number of single-institution studies challenged the belief that urgent surgical debridement decreases the risk of acute infection. METHODS We performed a retrospective, multicenter study of open fractures that had been treated at six tertiary pediatric medical centers between 1989 and 2000. The standard protocol at each medical center was for all children to be given intravenous antibiotics upon arrival in the emergency department. The medical records of all children with open fractures were reviewed to identify the location of the fracture, the interval between the injury and the time of surgery, the Gustilo and Anderson classification, and the occurrence of acute infection. RESULTS The analysis included 554 open fractures in 536 consecutive patients who were eighteen years of age or younger. The overall infection rate was 3% (sixteen of 554). The infection rate was 3% (twelve of 344) for fractures that had been treated within six hours after the injury, compared with 2% (four of 210) for those that had been treated at least seven hours after the injury; this difference was not significant (p = 0.43). When the fractures were separated according to the Gustilo and Anderson classification system, there were no significant differences in the infection rate between those that had been treated within six hours after the injury and those that had been treated at least seven hours after the injury. Specifically, these infection rates were 2% (three of 173) and 2% (two of 129), respectively, for type-I fractures, 3% (three of 110) and 0% (zero of forty-four), respectively, for type-II fractures, and 10% (six of sixty-one) and 2% (two of thirty-seven), respectively, for type-III fractures (p > 0.05 for all three comparisons). CONCLUSIONS In the present retrospective, multicenter study of children with Gustilo and Anderson type-I, II, and III open fractures, the rates of acute infection were similar regardless of whether surgery was performed within six hours after the injury or at least seven hours after the injury. The findings of the present study suggest that, in children who receive early antibiotic therapy following an open fracture, surgical debridement within six hours after the injury offers little benefit over debridement within twenty-four hours after the injury with regard to the prevention of acute infection.

Secondary fractures associated with external fixation in pediatric femur fractures.

Sixty-six femur fractures sustained by children ages 4-14 years and treated with external fixation were reviewed retrospectively to assess factors influencing the incidence of refracture. The total rate of secondary fracture was 12% (eight patients) including five recurrent fractures at the original fracture site and three fractures through the pin sites. After removal of the external fixator, five patients refractured at the original fracture site and one patient fractured through a pin tract. Two patients fractured at pin sites while the fixator was still in place. Multivariate linear-regression analysis showed no correlation between the incidence of refracture and fracture pattern, percentage of bone fragment contact after fixator application, type of external fixator, or dynamization. A statistically significant association (p < 0.05) was found between the number of cortices demonstrating bridging callus [on both anteroposterior (AP) and lateral views] at the time of fixator removal and the rate of refracture. Fractures showing fewer than three cortices of bridging callus had a three (33%) in nine rate of refracture, whereas fractures with three or four cortices of bridging callus had a two (4%) of 57 rate of refracture.

Lengthening of Dual Growing Rods and the Law of Diminishing Returns

Study Design. A retrospective multicenter study. Objective. To evaluate the effect of repeated surgical lengthenings and time on spinal growth and Cobb angle in children with early onset scoliosis and dual growing rods. Summary of Background Data. Previous studies have established the effectiveness of dual growing rods for controlling spinal deformity and promoting spinal “growth.” Although anecdotal experience suggests that the effectiveness of repeated lengthenings decreases over time, this has not been previously studied. Methods. Medical records from five different centers were reviewed to identify children treated with dual growing rods for early onset scoliosis who had a minimum of 2-year follow-up and at least three lengthening procedures. Initial radiographs, postimplantation radiographs, and radiographs from before and after each lengthening were measured for T1-S1 distance and Cobb angle. Linear regression and analysis of variance were used for statistical analysis. Results. Thirty-eight patients from five centers met the inclusion criteria. The average age of our patients was 5.7 years (range 1.7–8.9 years); mean follow-up was 3.3 years (range 2–7 years). The average interval between lengthenings was 6.8 months. Cobb angle decreased from a mean value of 74° preoperatively to 36° after the primary implantation and did not change significantly with repeated lengthenings (P = 0.96). After initial implantation, the average annual T1–S1 gain was 1.76 ± 0.71 cm/year. The T1-S1 gain after a given lengthening, however, decreased significantly with repeated lengthenings (P = 0.007). When the effect of time was considered, there was also a significant decrease in T1–S1 gain over time (P = 0.014). Conclusion. There seems to be a “law of diminishing returns” with repeated lengthenings of dual growing rods. Repeated lengthenings still result in a net T1-S1 increase; however, this gain tends to decrease with each subsequent lengthening and over time. This phenomenon may be due to autofusion of the spine from prolonged immobilization by a rigid device.