Richard Schwend

Differential rod contouring is used to achieve 3-dimensional correction in adolescent idiopathic scoliosis instrumentations. How vertebral rotation correction is correlated with the amount of differential rod contouring is still unknown; too aggressive differential rod contouring may increase the risk of bone-screw connection failure. The objective was to assess the 3-dimensional correction and bone-screw forces using various configurations of differential rod contouring. Computerized patient-specific biomechanical models of 10 AIS cases were used to simulate AIS instrumentations using various configurations of differential rod contouring. The tested concave/convex rod configurations were 5.5/5.5 and 6.0/5.5mm diameter Cobalt-chrome rods with contouring angles of 35°/15°, 55°/15°, 75°/15°, and 85°/15°, respectively. 3-dimensional corrections and bone-screw forces were computed and analyzed. Increasing the difference between the concave and convex rod contouring angles from 25° to 60...

ABSTRACT Study Design. A retrospective review of transpedicular instrumentation used in a series of 24 patients with myelodysplastic spinal deformities and deficient posterior elements. Objective. To describe the usefulness and efficacy of these instruments in the treatment of complicated myelodysplastic spinal deformity. Methods. The mean preoperative scoliosis was 75.7° (range, 39‐130°) in the 22 patients with scoliotic deformities; 4 patients with thoracic hyperkyphoses averaged 70.5° (range, 46‐90°) and 10 patients with lumbar kyphoses averaged 80.5° (range, 42‐120°). The instrumentation extended to the sacrum in 4 patients and the pelvis in 9; 10 patients also underwent anterior release and fusion and 7 underwent concomitant spinal cord detethering. At an average follow‐up of 4.0 years (2.0‐7.7 years; one patient died at 8 months), all patients have fused (with the exception of two lumbosacral pseudarthroses). Results. At last follow‐up, deformity measured 32.1° scoliosis (range, 6‐85°), 30.8° thoracic kyphosis (range, 24‐35°), and 0.0° lumbar kyphosis (range, 35° kyphosis to 29° lordosis). Three patients lost some neurologic function after surgery; two recovered within 6 months and one has incomplete recovery. No ambulatory patient lost the ability to walk. Five patients required additional surgical procedures; in three cases, there was instrumentation breakage associated with pseudarthrosis or unfused spinal segments. Conclusions. Pedicle screw instrumentation is uniquely suited to the deficient myelodysplastic spine. Compared with historical control subjects, these devices have proven capable of significant correction of both scoliotic and kyphotic deformities. This instrumentation appears particularly useful in preserving lumbar lordosis in all patients and may preserve more lumbar motion in ambulatory myelodysplasia patients.

Developmental dysplasia of the hip (DDH) encompasses a spectrum of physical and imaging findings. The child's hip will not develop normally if it remains unstable and anatomically abnormal by walking age. Therefore, careful physical examination of all infants to diagnosis and treat significant DDH is critical to provide the best possible functional outcome. Regardless of the practice setting, all health professionals who care for newborns and infants should be trained to evaluate the infant hip for instability and to provide appropriate and early conservative treatment or referral.

A simple and inexpensive method was developed to obtain a coaxial view of the pedicles to assist with screw insertion. The authors evaluated the accuracy of this device to place transpedicular vertebral screws in a human adult cadaver model. A dual radiation targeting system, a laser targeting system for fluoroscopically guided procedures, was developed to provide an accurate surface entry point and angle of approach to radiographic landmarks. After fluoroscopic cross-hair target localization of the coaxial view of the pedicle, X-ray radiation is turned off and the laser beam allows the surgeon to guide the screw through the pedicle. Nine cadaver spines were removed and mounted. Three surgeons, inexperienced in the technique of pedicle screw placement, fitted instruments to 184 pedicles between L5 and T5. A total of 83 lumbar and 101 thoracic pedicles underwent screw placement. After specimen dissection, the degree and location of any screw perforation were measured by direct inspection. Three screws perforated a pedicle, for an error rate of 1.6%. Two lumbar screws (2.4% error) and one thoracic screw (1% error) perforated the pedicle. No screw was more than 1 mm outside the pedicle. Five other screws, four in the thoracic spine and one in the lumbar spine (error rate of 2.7%) were directed too far laterally and perforated the lateral vertebral body. This low rate of pedicle wall cortical perforation by inexperienced surgeons compares favorably with much higher pedicle perforation rates by experienced surgeons when no imaging was used. In conclusion, this in vitro model using a dual radiation targeting system assisted with the accurate placement of transpedicular vertebral screws with minimal radiation exposure.

Approximately one third of medical problems in children are related to the musculoskeletal system. Most of these problems are common and can be precisely diagnosed. For these problems, nonoperative treatment or reassurance can be given by the pediatrician. Occasionally, a problem needs surgical treatment, but a precise diagnosis must be made. There is little agreement about what types of orthopedic problems a primary care pediatrician should understand in order to effectively care for children. Many pediatric residencies lack an organized teaching curriculum that effectively covers these topics or that includes a required pediatric orthopedic rotation. In this article the authors delineate pediatric orthopedic problems that: Require recognition and urgent surgical treatment.Are relatively common, but have different treatment options (observation, conservative treatment, and surgery) depending on their natural history.Are common, need no surgical treatment, and are well managed by the pediatrician without referral.Whenever possible, the diagnosis should be made before a decision to refer is made.There are several reasons for this: An accurate diagnosis allows the pediatrician to discuss the natural history of the condition properly. The parents can be reassured rather than waiting to hear the same information from another physician. In particular, orthopedic problems are known to generate pressure from the parents to seek specialty consultation for reassurance.5 Although some of these referrals are unavoidable, it is important to communicate to the specialist that the reason for the referral is for parental reassurance rather than for further work-up or treatment.Referral to the wrong specialty can needlessly generate expensive tests and further delay in treatment or generate inappropriate treatment.22 For instance, an adolescent with back pain may have underlying school and home stress with depression and require further evaluation of these aspects of his or her life. A 5-year-old may have leukemic involvement of the spine. Referral of either of these children could delay diagnosis and treatment. A spinal cord tumor should be referred to the neurosurgeon, while vertebral osteomyelitis and discitis should be referred to the orthopedic surgeon. In each case, focused and timely referral depends on an accurate and specific diagnosis.After a proper diagnosis, communication directly between the pediatrician and the appropriate specialist can often avoid an unnecessary referral, and avoid unnecessary tests.The authors reviewed their experience of referrals from primary care physicians over 1 year. The authors found that patients were usually referred to them for a symptom (i.e., hip pain) rather than for a specific diagnosis. Ninety-five percent of patients were eventually able to receive a diagnosis. Approximately 40% of these referrals involved problems that could have been managed by the referring physician since they did not require any further work-up or treatment, usually just reassurance or education. The authors found that it is useful to classify conditions as common or uncommon, and whether they require surgical or nonsurgical treatment (Table 1); many conditions fall in between. The following is a discussion of some of these more important or common conditions.

Case report of two children sustaining venous air embolism (VAE) during posterior surgery for scoliosis. To report 2 cases where visible bubbling at the operative site was the first clinical indication of VAE-induced cardiovascular collapse and to raise the level of consciousness that VAE in the prone position can occur, often with serious consequences. Twenty-two cases of VAE during surgery for scoliosis in the prone position have been reported. Ten were fatal and ten were in children. Visible bubbling at the operative site was noted in two published cases. Retrospective study of 2 cases of VAE at one institution. Clinical, anesthetic, and radiographic features are presented. Details of previously published cases are reviewed and discussed. Both patients were girls with adolescent scoliosis who underwent prone positioned posterior spinal fusion with instrumentation. Visible bubbling of air at the thoracic aspect of the surgical site was noted near the completion of instrumentation and was the first indication of VAE. In both cases, this was clinically recognized and promptly treated. One patient survived normally and the other died. Visible air bubbling at the operative site may herald the onset of massive VAE during multilevel posterior spinal fusion and instrumentation. A prospective multicenter study using precordial Doppler, central venous catheter, and end-tidal CO2 is recommended to determine the true incidence of VAE in spinal deformity surgery and to evaluate monitoring and treatment methods.

A matched cohort comparison of adult idiopathic scoliosis (AdIS) patients treated with all pedicle screw constructs compared to hook/hybrid constructs. To compare clinical and radiographic results of AdIS treatment using all pedicle screw constructs versus hook/hybrid constructs. Pedicle screw instrumentation has demonstrated excellent clinical efficacy in the treatment of pediatric spinal deformity. No prior reports have compared the outcomes of pedicle screw only constructs to hook/hybrid constructs in the treatment of AdIS. We analyzed 34 consecutive patients undergoing posterior-only correction for AdIS, using pedicle screw instrumentation at minimum 2-year follow-up. Thirty-four matching patients (11 with anterior releases) were selected from a cohort of 58 patients treated with hook/hybrid constructs based on similar age, curve type, magnitude, and fusion levels. Significantly greater curve correction was seen in the pedicle screw compared to the hook/hybrid group (56 vs. 40%, P < 0.01). Coronal and sagittal imbalance were equivalent between the groups (P = 0.91 and 0.23, respectively). Thoracic kyphosis (T5-T12) was maintained in the pedicle screw patients but significantly increased in the hybrid/hook patients over time (P < 0.05). Scoliosis Research Society outcome scores significantly improved in both groups. Blood loss was equivalent but operative time was longer in the hook/hybrid patients.No pedicle screw patients were revised for instrumentation complications with 1 lumbosacral nonunion revised at 5 years postoperative (3% revision rate). Eight of 58 patients among the hook/hybrid cohort underwent 9 revisions for instrumentation failure (n = 3) or nonunion (n = 6) (14% revision rate; P = 0.04). Pedicle screw correction of AdIS is safe and effective. Compared to hook/hybrid constructs, these patients displayed significantly improved correction of the major curve (even in the absence of anterior releases), maintenance of thoracic kyphosis, and a lower revision rate. Similar SRS scores and blood loss were noted. The hook/hybrid patients had significantly longer operative times. The use of BMP-2 in 7 patients and TLIF/ALIF also in 7 of the pedicle screw patients may have decreased the need for revision surgery up to the latest follow-up.

Congenital vertebral dislocation (CVD) is a rare congenital spinal malformation characterized by a translatory or rotatory vertebral displacement, or both, at a single level, that results in an abrupt angulation of the neural canal. The more caudal vertebra is dysplastic and appears at first glance to be posteriorly dislocated into the vertebral canal as a posterior hemivertebra, but is actually well aligned with the more caudal vertebral column. Unfortunately, the present classification of complex congenital vertebral anomalies is confusing, and CVD has been grouped together with other congenital vertebral malformations under the terms 'segmental spinal dysgenesis', 'medial spinal aplasia', and others. Moreover, a putative embryonic mechanism has never been proposed for CVD. Based upon our experience with 6 children and a critical review of the literature, we identify CVD as a distinct entity having characteristic anatomical features. We propose a novel putative embryonic mechanism - early embryonic 'buckling' - which likely occurs by the 6th embryonic week, prior to the period of axonal outgrowth and the beginning of vertebral chondrification.

Displaced distal physeal fractures of the radius are at risk for development of median neuropathy. The mechanism of injury includes compression of the nerve by the displaced fracture, contusion of the nerve at the time of fracture or reduction, or the development of a compartment syndrome. Patients with significant soft-tissue swelling and symptoms or signs of median nerve dysfunction are especially at risk for worsening neuropathy after closed reduction and closely applied cast immobilization or after open reduction. Closed reduction and percutaneous pin fixation may be the optimal treatment for these patients.

Nonoperative management of clubfoot with the Ponseti method has proven to be effective, and it is the accepted initial form of treatment. Although several studies have shown that problems with compliance with the brace protocol are principally responsible for recurrence, no distinction has been made with regard to whether the distance from the site of care affects the early recurrence rate. We compared early recurrence after Ponseti treatment between rural and urban ethnically diverse North American populations to analyze whether distance from the site of care affects compliance and whether certain patient demographic characteristics predict recurrence. One hundred consecutive infants with a total of 138 clubfeet treated with the Ponseti method were followed prospectively for at least two years from the beginning of treatment. Early recurrence, defined as the need for subsequent cast treatment or surgical treatment, and compliance, defined as strict adherence to the brace protocol described by Ponseti, were analyzed with respect to the distance from the site of care, age at presentation, number of casts needed for the initial correction, need for tenotomy, and family demographic variables. Of eighteen infants from a rural area who had early recurrence, fourteen were Native American. The families of these children, like those of all of the children with early recurrence, discontinued orthotic use earlier than was recommended by the physician. Discontinuation of orthotic use was related to recurrence, with an odds ratio of 120 (p < 0.0001), in patients living in a rural area. Native American ethnicity, unmarried parents, public or no insurance, parental education at the high-school level or less, and a family income of less than $20,000 were also significant risk factors for recurrence in patients living in a rural area. Intrinsic factors of the clubfoot deformity were not correlated with recurrence or discontinuation of bracing. Compliance with the orthotic regimen after cast treatment is imperative for the Ponseti method to succeed. The striking difference in outcome in rural Native American patients as compared with the outcomes in urban Native American patients and children of other ethnicities suggests particular problems in communicating to families in this subpopulation the importance of bracing to maintain correction. An examination of communication styles suggested that these communication failures may be culturally related.

Patients born in the Many Farms District of the Navajo Indian Reservation from 1955 to 1961 were studied. Five hundred forty-eight of the 628 infants born (87%) received clinical examinations and pelvic radiographs at some time during the first 4 years of their lives. Eighteen (3.3%) of the 548 infants examined had acetabular dysplasia. Because of traditional cultural beliefs, none of these children received medical treatment. Followup evaluations and radiographs were obtained in these 18 patients during early adolescence. In 10 of the original 18 patients followup evaluations and radiographs were obtained at an average age of 35 years. None of the dysplastic hips progressed to frank dislocation. The mean center edge angle improved from 7 degrees when the patients were 1 year of age, to 29 degrees when the patients were 12 years of age, to 30 degrees when the patients were 35 years of age. Despite overall improvement of hip measurements with maturity, eight hips in five of the 10 patients who were in their fourth decade of life and who were available for examination, had radiographic evidence of residual abnormalities. The hips in patients with subluxation during infancy were less likely to be normal as adults. The results of this 34-year followup study of untreated developmental hip dysplasia showed marked radiographic improvement in all patients during childhood; however, subtle abnormalities persisted in the radiographs of 40% of the hips.

Catastrophic head injuries in football are rare but tragic events. To update the profile of catastrophic head injuries in high school and college football players and to describe relevant risk factors. Case series; Level of evidence, 4. We reviewed 94 incidents of severe football head injuries reported to the National Center for Catastrophic Sports Injury Research during 13 academic years (September 1989 through June 2002). In the study period there were an average of 7.23 (standard deviation = 2.05) direct high school and college catastrophic head injuries in scholastic football participants per year. There were 0.67 injuries per 100 000 (95% confidence interval: 0.54, 0.81 per 100 000) high school and 0.21 injuries per 100 000 (95% confidence interval: 0.0, 0.49 per 100 000) college participants for a risk ratio of 3.28 (95% confidence interval: 0.81, 13.3). The injuries resulted in subdural hematoma in 75 athletes, subdural hematoma with diffuse brain edema in 10 athletes, diffuse brain edema in 5 athletes, and arteriovenous malformation or aneurysm in 4 athletes. Fifty-nine percent of the contacts reported that the athlete had a history of a previous head injury, of which 71% occurred within the same season as the catastrophic event. Thirty-nine percent of the athletes (21 of 54) were playing with residual neurologic symptoms from the prior head injury. There were 8 (9%) deaths as a result of the injury, 46 (51%) permanent neurologic injuries, and 36 (40%) serious injuries with full recovery. Most players sustained a major impact to the head either from tackling or being tackled. The incidence of catastrophic head injuries in football has remained low since the advent of the modern day football helmet in the early 1970s. The incidence of catastrophic head injuries in football is dramatically higher at the high school level than at the college level. Although the reason for this discrepancy is unclear, an unacceptably high percentage of high school players were playing with residual symptoms from a prior head injury. Coaches, athletes, athletic trainers, and medical personnel need to adhere to the guideline that an athlete with any neurologic symptoms from a head injury should be strongly discouraged from returning to play.