Randall T. Loder

Acute slipped capital femoral epiphysis: The importance of physeal stability

To test the traditional classification system of slipped capital femoral epiphysis, we evaluated the presenting symptoms and radiographs of fifty-four patients and reclassified the slipped epiphyses as unstable or stable, rather than acute, chronic, or acute-on-chronic. Slips were considered to be unstable when the patient had such severe pain that weight-bearing was not possible even with crutches. Slips were considered to be stable when the patient could bear weight, with or without crutches. We reviewed the records on fifty-five hips in which the slip would have been classified as acute because the duration of symptoms was less than three weeks; thirty of these were unstable and twenty-five were stable. All slips were treated with internal fixation. A reduction occurred in twenty-six of the unstable hips and in two of the stable hips. Fourteen (47 per cent) of the thirty unstable hips and twenty-four (96 per cent) of the twenty-five stable hips had a satisfactory result. Avascular necrosis developed in fourteen (47 per cent) of the unstable hips and in none of the stable hips. We were not able to demonstrate an association between early reduction and the development of avascular necrosis.

Slipped capital femoral epiphysis.

Slipped capital femoral epiphysis is a well known disorder of the hip in adolescents that is characterized by displacement of the capital femoral epiphysis from the metaphysis through the physis. The term slipped capital femoral epiphysis is a misnomer because the epiphysis is held in the acetabulum by the ligamentum teres, and thus it is actually the metaphysis that moves upward and outward while the epiphysis remains in the acetabulum. In most patients, there is an apparent varus relationship between the head and the neck, but occasionally the slip is into a valgus position, with the epiphysis displaced superiorly in relation to the neck106,109. In the vast majority of cases, the etiology is unknown. Although the condition may be associated with a known endocrine disorder71,77,129, with renal failure osteodystrophy74, or with previous radiation therapy75,77, this Instructional Course Lecture deals only with idiopathic slipped capital femoral epiphysis. Multiple theories have been proposed for the etiology of idiopathic slipped capital femoral epiphysis, and it is likely a result of both biomechanical and biochemical factors128. The combination of these factors results in a weakened physis with subsequent failure. Mechanical factors95 associated with the disorder are obesity62,72, increased femoral retroversion36,37,95, and increased physeal obliquity83. The vast majority of children with a slipped capital femoral epiphysis are obese, which increases the shear stress across the physis. Obesity is also associated with femoral retroversion, with anteversion averaging 10.6 degrees in adolescents with normal weight but only 0.40 degree in obese adolescents36. This femoral retroversion increases the stress across the physis95. Children with a slipped capital femoral epiphysis also have a more …

The demographics of slipped capital femoral epiphysis: An international multicenter study

One thousand six hundred thirty children with 1993 slipped capital femoral epiphyses were reviewed; 41.2% were girls and 58.8% were boys. There were 47.5% white, 24.8% black, 16.9% Amerindian, 7.4% Indonesian-Malay, 2.1% Native Australian/Pacific Islands, and 1.3% Indo-Mediterranean children. The diseased hip was unilateral in 77.7% and bilateral in 22.3% of the children, and chronic in 85.5% and acute in 14.5% of the children. Of the unilateral slips, 40.3% involved the right hip and 59.7% the left hip. The childs weight was greater than or equal to the ninetieth percentile in 63.2% of the children. The average age for the girls and boys was 12 and 13.5 years. The age at diagnosis decreased with increasing obesity. The youngest children were the Native Australian/Pacific Island children (11.8 years) and the oldest were the white and Indo-Mediterranean children (13 years). The Indonesian-Malay and Indo-Mediterranean children were the lightest in weight, and the black children the heaviest. The Indo-Mediterranean children had the highest proportion of boys (90.5%), and the Native Australian/Pacific Island children the lowest (50%). The highest percentage of bilaterality was in the Native Australian/Pacific Island children (38.2%), and the lowest in the Amerindian children (16.5%). The relative racial frequency of slipped capital femoral epiphysis compared with the white population was 4.5 for the Polynesian, 2.2 for the black, 1.05 for the Amerindian, 0.5 for the Indonesian-Malay, and 0.1 for the Indo-Mediterranean children. In children with unilateral involvement, the age at presentation was younger for those children in whom bilateral disease later developed (12 versus 12.9 years old). In 82% of the children with sequential bilateral slips, the second slip was diagnosed within 18 months of the first slip.

Measurement error of lumbar total disc replacement range of motion.

Study Design. A retrospective review of lumbar total disc replacement (TDR) radiographs. Objective. To determine the error and variability in measuring TDR radiographic range of motion (ROM). Summary of Background Data. Motion preservation is the driving force behind lumbar TDR technology. In the recent literature, sagittal radiographic TDR ROM as low as 2° has been reported. In these studies, ROM was determined by using the Cobb method to measure TDR sagittal alignment angles in flexion-extension lateral radiographs. However, previous studies in the spinal deformity literature have shown that the Cobb method is very susceptible to measurement error. Methods. There were 5 observers, including 2 attending orthopedic spine surgeons, 1 spine fellow, 1 fifth-year resident, and 1 fourth-year resident, who measured the ROM of 50 ProDisc II (Synthes Spine Solutions, New York, NY) TDRs on standard flexion-extension lumbar spine radiograph sets. Repeated measurements were made on 2 occasions using the Cobb method. Measurement variability was calculated using 3 statistical methods. Results. The 3 statistical methods resulted in extremely similar values for TDR ROM observer variability. Overall, the intraobserver variability of TDR ROM measurement was ±4.6°, and interobserver variability was ±5.2°. Conclusions. To be 95% certain that an implanted TDR prosthesis has any sagittal motion, a ROM of at least 4.6° must be observed, which is the upper limit of intraobserver measurement variability for a TDR with a true ROM of 0°. To be 95% certain that a change in TDR ROM has occurred between 2 measurements by the same observer, a change in ROM of at least 9.6° must be observed (the entire range of ±4.6° intraobserver variability). ROM measurement variability should be considered when evaluating the success or failure of motion preservation in lumbar TDR.

The epidemiology of bilateral slipped capital femoral epiphysis. A study of children in Michigan

The records of 224 children who had a slipped capital femoral epiphysis and who had no underlying metabolic or endocrine disorder were studied retrospectively to investigate the epidemiology of bilateral slipped capital femoral epiphysis. Eighty-two (37 per cent) of the 224 children (fifty-one boys and thirty-one girls) had a bilateral slip. Sixty-four of these children were black and eighteen were white. The age at the time of the diagnosis of the first slip was 13 +/- 1.7 years (mean and standard deviation), the duration of the symptoms was 5 +/- 5.0 months, and the angle of the slip was 26 +/- 16 degrees. Obese children were younger at the time of the diagnosis of the first slip (12 +/- 1.6 compared with 13 +/- 1.6 years for the children who were not obese, p = 0.001). The diagnosis of a slipped capital femoral epiphysis was made simultaneously in both hips in forty-one children and sequentially in forty-one children. Compared with the children in whom both hips were diagnosed simultaneously, the children in whom the hips were diagnosed sequentially had had a shorter duration of the symptoms before the diagnosis of the first slip (3 +/- 2.4 compared with 7 +/- 5.9 months, p = 0.0003), were younger at the time of the diagnosis of the first slip (12 +/- 1.9 compared with 13 +/- 1.2 years, p = 0.001), and tended to be more obese (p = 0.025). In 88 per cent of the patients who had sequential slips, the second slip was diagnosed within eighteen months after the diagnosis of the first slip.(ABSTRACT TRUNCATED AT 250 WORDS)

Slipped capital femoral epiphysis associated with endocrine disorders.

We reviewed 85 patients with endocrine disorders and slipped capital femoral epiphysis (SCFE). The disorders were hypothyroidism (40%), growth hormone deficiency (25%), and others (35%). The average age at diagnosis of the disorder was 13.2 +/- 6.2 years and 15.3 +/- 5.3 years at diagnosis of the first SCFE. In 53 hips, the bone and chronologic age were both known: 11.6 +/- 3.0 years bone age, 16.5 +/- 6.5 years chronologic age, p < 0.01. The age at presentation of the first SCFE ranged from 7-35 years; only those with hypothyroidism or growth hormone deficiency were < 10 years of age; all patients with other endocrinopathies, when seen first with an SCFE at an atypical age, were > 16 years. The hypothyroid patients usually had the endocrine diagnosis made at presentation of the first SCFE; the growth hormone-deficient children usually had the endocrine diagnosis made before that of the SCFE (p < 0.01). None of those in whom the diagnosis of the endocrine disorder occurred after the diagnosis of the SCFE was hypothyroid or growth hormone deficient. All hypothyroid patients developed the first SCFE before or during hormonal supplementation; 92% with growth hormone deficiency developed the SCFE during or after supplementation (p < 0.01). Because the prevalence of bilaterality was 61% (p < 0.01), prophylactic treatment of the opposite hip should be considered.

Slipped capital femoral epiphysis: current concepts.

&NA; Slipped capital femoral epiphysis is a common hip disorder in adolescents, with an incidence of 0.2 (Japan) to 10 (United States) per 100,000. The etiology is unknown, but biomechanical and biochemical factors play an important role. Symptoms at presentation include pain in the groin, thigh, or knee. Ambulatory patients also may present with a limp. Nonambulatory patients present with excruciating pain. The slipped capital femoral epiphysis is classified as stable when the patient can walk and unstable when the patient cannot walk, even with the aid of crutches. Because the epiphysis slips posteriorly, it is best seen on lateral radiographs. The treatment of choice for stable slipped capital femoral epiphysis is single‐screw fixation in situ. This method has a high probability of long‐term success, with minimal risk of complications. In the patient with unstable slipped capital femoral epiphysis, urgent hip joint aspiration followed by closed reduction and single‐ or doublescrew fixation provides the best environment for a satisfactory result, while minimizing the risk of complications.

Slipped Capital Femoral Epiphysis. The Prevalence of Late Contralateral Slip

We evaluated the prevalence of slipped capital femoral epiphysis in the contralateral hip of 169 children who had been managed with pinning in situ and thirty who had been managed with immobilization in a spica cast. Only children who had initially been seen with a unilateral slip and had been followed for a minimum of two years or until skeletal maturity were included in the study. The average duration of follow-up was 3.6 years (range, 0.5 to 9.5 years) for the group that had been managed with a cast and 2.8 years (range, 1.0 to 8.3 years) for the group that had been managed operatively. In sixty-one (36 per cent) of the 169 patients who had had operative treatment and two (7 per cent) of the thirty who had been managed with a spica cast, a slip subsequently developed in the contralateral hip; this difference was significant (p = 0.001). On the basis of these findings, we recommend that closer attention be paid to the potential development of a slip in the contralateral hip after pinning.

Aneurysmal bone cysts in young children

We reviewed seven young children (< or = 10 years) with aneurysmal bone cysts. There were four girls and three boys. Six had involvement of the long bones and one had involvement of the clavicle. The average age was 5.5 years (range 2.9-10.6 years). Initial treatment was curettage and bone grafting. There were recurrences in five of the seven children (71%). This represented 100% of children with radiographically aggressive or active lesions. The recurrences appeared rapidly, at an average of 8 months from the first procedure. The mitotic index of the initial lesion did not correlate with that of the recurrent lesion. Surgical management of the recurrences must be handled individually, but repeat curettage and grafting is only recommended when surgical resection is not possible. This high rate of recurrence in radiographically aggressive or active aneurysmal bone cysts in young children should be considered when planning treatment, and in the preoperative counseling of parents.

Treatment of the unstable (acute) slipped capital femoral epiphysis

Slipped capital femoral epiphysis, the most common hip disorder in adolescence, traditionally has been classified according to symptom duration. An acute slip is 1 in which there are symptoms for < 3 weeks; for a chronic slip, there are symptoms for > 3 weeks. An acute-on-chronic slip is characterized by a combination of both with a recent exacerbation of symptoms. This classification system is misleading because it does not consider stability. A stable slipped capital femoral epiphysis has a good prognosis, but an unstable slip has a guarded prognosis. The priorities in treating an unstable (acute) slip are (1) to avoid avascular necrosis, (2) to avoid chondrolysis, (3) to prevent further slip, and (4) to correct deformity. The last priority, correcting the deformity, is associated with a high incidence of complications including avascular necrosis and chondrolysis, so manipulative reduction under anesthesia or an acute corrective osteotomy is not recommended. To address these priorities in treatment, the authors recommend preoperative bed rest to decrease the synovitis and intraarticular effusion. Operative stabilization is done in an elective fashion once the synovitis has subsided. The technique includes careful patient positioning on the fracture table, which may cause an incidental reduction, but no attempt is made to do a manipulative reduction. The technique is dependent on radiographic control. The femoral head and neck must be well visualized on the anteroposterior and lateral intensifier images before the operation is started. The slipped capital femoral epiphysis is stabilized with a single central screw, and nonweightbearing ambulation with crutches is recommended until a satisfactory painless range of motion has returned.