Faculty Bibliography

BACKGROUND: Recent studies have suggested that perfusion magnetic resonance imaging (pMRI) using gadolinium contrast and a subtraction technique can provide useful prognostic information in Legg-Calve-Perthes disease (LCPD) and allow earlier stratification for outcome. There are, however, sparse data available regarding the feasibility and safety of these studies in children. The purpose of this study was to collect this information across multiple centers using pMRI for LCPD. METHODS: We retrospectively reviewed a consecutive series of patients with confirmed or suspected LCPD who had undergone pMRI at 1 of 5 large tertiary-care children's hospitals in the United States, UK, and Mexico. Demographic information, type of contrast administered, and requirement for sedation or anesthesia were noted. Records were scrutinized for adverse events associated with the pMRI protocol. RESULTS: Over the study period, 165 patients underwent 298 pMRI studies. The median age at the time of imaging was 8.6 years (range, 2.5to 16.9 y). A total of 252 scans (85%) were performed for a known diagnosis of LCPD, whereas 46 were performed for a suspected diagnosis. Ninety-two of the 298 (31%) pMRIs required sedation, 48 (16%) required general anesthesia, and 122 (41%) were facilitated by video goggles only. The remaining 36 patients (12%) had their studies performed without additional measures. The ages of patients requiring sedation (mean, 7.2+/-2.4 y) and anesthesia (mean, 7.7+/-2.3 y) were significantly younger than those patients requiring neither (mean, 10.2+/-2.3 y, P<0.001). Four patients (1.3%) reported nausea or vomiting as a result of sedation. Two patients (0.7%) had complications from intravenous cannulation (pull out, difficult access). One child (0.3%) had nausea/vomiting as a result of contrast administration. There were no serious adverse events as a result of the pMRI protocol; specifically none of nephrogenic systemic fibrosis, anaphylaxis, or death. CONCLUSIONS: pMRI is a safe and feasible imaging technique for LCPD. Almost half of our patients required either sedation or general anesthesia to complete the study. LEVEL OF EVIDENCE: IV (case series).

BACKGROUND: The presence of femoroacetabular impingement (FAI) after a slipped capital femoral epiphysis is thought to predispose the subsequent development of osteoarthritis (OA); however, there is a lack of evidence to support this hypothesis. METHODS: One hundred twenty-one patients with stable slipped capital femoral epiphysis treated with in situ fixation were reviewed at a minimum of 20-year follow-up; the presence of a pistol grip deformity and FAI was determined. The Harris Hip Score (HHS) was used to measure clinical outcome, and the Tonnis grade for qualifying the presence of OA was determined. RESULTS: One hundred twenty-one patients were followed up at a mean of 22.3 years (range, 20.1 to 32.5 y); the slip was considered grade 1 in 34 hips, grade 2 in 65 hips, and grade 3 in 22 hips. Ninety-six patients had clinical and radiographic signs of FAI. The mean HHS for the entire cohort was 75.6; however, for the 25 patients without FAI it was 89.3 and for the 96 patients with FAI it was 75.4 (P=0.004). We found radiographic signs of OA in all 121 patients: considered grade 1 in 14 hips, grade 2 in 32 hips, and grade 3 in 75 hips. The mean Tonnis grade of OA was 2.5. A direct relationship between the radiographic grade of OA and the HHS was observed. CONCLUSIONS: The occurrence of FAI (or a pistol grip deformity) after even a low-grade slip is common. We found clinical and radiographic signs of FAI in most of our patients, and also found that the degree of deformity is directly related to the presence of OA in early adulthood.

Early diagnosis is of paramount importance to favorably alter the natural history of DDH. Most cases of dysplasia can be diagnosed by careful history taking and physical examination. Imaging modalities, such as ultrasonography, have increased our ability to detect subtleties not appreciated by means of physical examination or plain radiography. Although the evaluation of children with risk factors for DDH is important, most dysplasia occurs in girls who have no other risk factors. For all infants, a competent newborn physical examination using the Ortolani maneuver is the most useful procedure to detect hip instability. Early treatment of an unstable hip with a Pavlik harness or similarly effective orthosis is effective, safe, and strongly advised.

BACKGROUND: We sought to determine the functional outcome of patients with grade 3 slipped capital femoral epiphysis who had been treated with in situ pinning at a mid-term follow-up. METHODS: One hundred and five patients with 129 slips (24 bilateral) were reviewed. Minimum follow-up was 5 years and mean follow-up was 66 months. Slips over 60 degrees were considered grade 3. All of the patients underwent in situ pinning with a single cannulated screw; the placement of the screw was evaluated with the criteria of Stambough. The final evaluation was performed using the Iowa Hip Score and results were analyzed by sex, age at time of diagnosis, and body mass index. Statistical analysis was carried out using the Mann-Whitney U-test considering a P value of less than 0.005 to be statistically significant. RESULTS: The mean Iowa Hip Score was 84.73. Fifty-two patients were considered to have an excellent result, 28 a good result, 16 a fair result, and 9 a bad result. The pin placement was considered adequate in 89 patients and inadequate in 16 patients. Forty-three patients were girls and 62 were boys and no statistical difference was found in function by sex. The mean Iowa Hip Score for patients under 12 years of age (n=20) was 85.8, for those between 12 and 15 years of age (n=69) it was 82.8 and for those over 15 years of age (n=16) it was 82.5 (P=0.003). There were 10 complications, all in the group in which the pin placement was considered inadequate, and all of these were considered fair or poor results. CONCLUSIONS: The functional results in the mid-term for patients with grade 3 slips treated with in situ pinning were generally good or excellent; a better result was found in patients below 12 years of age. A good or excellent result can be expected when pin placement is adequate and no complications arise.

PURPOSE: We sought to determine if a varus-producing osteotomy of the proximal femur was related to a better outcome than non-operative treatment for LCP disease. METHODS: This was a retrospective review of 121 patients; clinical outcome was determined with the Iowa Hip Score, and radiographic outcome was determined with the Stulberg classification. RESULTS: A total of 73 patients undergoing a VO and 48 treated non-operatively were included; 70 had lateral pillar type B and 51 type C hips. Average follow-up was 12.03 years. The mean Iowa Hip Score was 86.8 for the VO group and 85.9 for the non-operative group. According to the Stulberg classification for the group undergoing a VO, there were 8 type II, 33 type III, and 32 type III, and for the group undergoing non-operative treatment there were 11 type II, 24 type III, and 13 type IV. CONCLUSIONS: We found no statistically significant difference in the clinical or radiographic result for patients undergoing a VO compared to non-operative treatment.

BACKGROUND: It is generally accepted that the presence of angular deformity about the knee that persists into the preadolescent years will not correct spontaneously. The goal of this study was to review our experience with hemiepiphysiodesis and physeal stapling for the correction of angular deformity to establish the efficacy of these procedures and to determine their indications and the rate of correction. METHODS: A retrospective review of 48 patients undergoing hemiepiphysiodesis or physeal stapling about the knee was performed. Patients were included if they had at least 2 years of documented follow-up without an osteotomy. RESULTS: The average follow-up was 30.4 months (range, 24-52 months). Genu varum was identified in 33 patients, genu valgum in 14 patients, and a windswept deformity in 1. Of the 52 limbs with genu varum, 35 were secondary to Blount disease. The group with genu varum unrelated to Blount disease presented a change in the mechanical axis from a mean of -32 degrees at surgery to a mean of - 13 degrees. The patients with Blount disease presented a change in the mechanical axis from a mean of -19 degrees at surgery to a mean of -16 degrees. The group with genu valgum presented a change in the mechanical axis from a mean of 20 degrees at surgery to a mean of 2 degrees. CONCLUSIONS: Hemiepiphysiodesis is an effective means for correcting angular deformity about the knee in skeletally immature patients with both genu valgum and genu varum, so long as the genu varum is unrelated to Blount disease. Hemiepiphysiodesis is effective in preventing the progression of deformity in patients with Blount disease. LEVEL OF EVIDENCE: Therapeutic-Level IV.