Faculty Bibliography

Purpose/UNASSIGNED:Patients with late-presenting developmental dysplasia of the hip (DDH) are more likely to require an open reduction. Since many developing countries do not have mandated screening, there continues to be a relatively high incidence of late-presenting DDH. We report the clinical and radiographic outcomes of open reduction in a series of patients who presented late. Patients and methods/UNASSIGNED:This was a retrospective review of 712 hips in 645 patients that underwent open reduction, alone or in combination with a pelvic osteotomy. In all, 91 hips had open reduction alone and 621 had open reduction and pelvic osteotomy. Femoral shortening was performed in 221 hips. The mean age at the time of surgery was 2.1 years (1 to 6.5) and the mean follow-up time was 9.3 years (6 to 14). We used the Children's Hospital Oakland Hip Evaluation Score (CHOHES) to determine functional outcomes and the Severin classification was used to evaluate radiographic outcomes. The rate of avascular necrosis (AVN) and the need for a reoperation were also recorded and analyzed. Results/UNASSIGNED:In all 80% (570 hips) had good radiographic outcomes (Severin type I or II) and 87% had a CHOHES score of > 90 at final follow up. There was a 14% rate of AVN and only a 2% rate of redislocation. Better radiographic outcomes and lower reoperation rates were seen with patients who underwent both an open reduction and pelvic osteotomy. A trend was observed towards worse outcomes in older patients. Conclusions/UNASSIGNED:There was a high rate of good clinical and radiographic outcomes at a minimum six-year follow-up in patients with late-presenting DDH who underwent open reduction. Those who underwent open reduction in combination with a pelvic osteotomy had a higher rate of good radiographic outcomes and a lower rate of complications, particularly reoperation.

BACKGROUND: The use of a brace has been shown to be an effective treatment for hip dislocation in infants; however, previous studies of such treatment have been single-center or retrospective. The purpose of the current study was to evaluate the success rate for brace use in the treatment of infant hip dislocation in an international, multicenter, prospective cohort, and to identify the variables associated with brace failure. METHODS: All dislocations were verified with use of ultrasound or radiography prior to the initiation of treatment, and patients were followed prospectively for a minimum of 18 months. Successful treatment was defined as the use of a brace that resulted in a clinically and radiographically reduced hip, without surgical intervention. The Mann-Whitney test, chi-square analysis, and Fisher exact test were used to identify risk factors for brace failure. A multivariate logistic regression model was used to determine the probability of brace failure according to the risk factors identified. RESULTS: Brace treatment was successful in 162 (79%) of the 204 dislocated hips in this series. Six variables were found to be significant risk factors for failure: developing femoral nerve palsy during brace treatment (p = 0.001), treatment with a static brace (p < 0.001), an initially irreducible hip (p < 0.001), treatment initiated after the age of 7 weeks (p = 0.005), a right hip dislocation (p = 0.006), and a Graf-IV hip (p = 0.02). Hips with no risk factors had a 3% probability of failure, whereas hips with 4 or 5 risk factors had a 100% probability of failure. CONCLUSIONS: These data provide valuable information for patient families and their providers regarding the important variables that influence successful brace treatment for dislocated hips in infants. LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND: Little information exists concerning the variability of presentation and differences in treatment methods for developmental dysplasia of the hip (DDH) in children < 18 months. The inherent advantages of prospective multicenter studies are well documented, but data from different centers may differ in terms of important variables such as patient demographics, diagnoses, and treatment or management decisions. The purpose of this study was to determine whether there is a difference in baseline data among the nine centers in five countries affiliated with the International Hip Dysplasia Institute to establish the need to consider the center as a key variable in multicenter studies. QUESTIONS/PURPOSES: (1) How do patient demographics differ across participating centers at presentation? (2) How do patient diagnoses (severity and laterality) differ across centers? (3) How do initial treatment approaches differ across participating centers? METHODS: A multicenter prospective hip dysplasia study database was analyzed from 2010 to April 2015. Patients younger than 6 months of age at diagnosis were included if at least one hip was completely dislocated, whereas patients between 6 and 18 months of age at diagnosis were included with any form of DDH. Participating centers (academic, urban, tertiary care hospitals) span five countries across three continents. Baseline data (patient demographics, diagnosis, swaddling history, baseline International Hip Dysplasia Institute classification, and initial treatment) were compared among all nine centers. A total of 496 patients were enrolled with site enrolment ranging from 10 to 117. The proportion of eligible patients who were enrolled and followed at the nine participating centers was 98%. Patient enrollment rates were similar across all sites, and data collection/completeness for relevant variables at initial presentation was comparable. RESULTS: In total, 83% of all patients were female (410 of 496), and the median age at presentation was 2.2 months (range, 0-18 months). Breech presentation occurred more often in younger (< 6 months) than in older (6-18 months at diagnosis) patients (30% [96 of 318] versus 9% [15 of 161]; odds ratio [OR], 4.2; 95% confidence interval [CI], 2.3-7.5; p < 0.001). The Australia site was underrepresented in breech presentation in comparison to the other centers (8% [five of 66] versus 23% [111 of 479]; OR, 0.3, 95% CI, 0.1-0.7; p = 0.034). The largest diagnostic category was < 6 months, dislocated reducible (51% [253 of 496 patients]); however, the Australia and Boston sites had more irreducible dislocations compared with the other sites (ORs, 2.1 and 1.9; 95% CIs, 1.2-3.6 and 1.1-3.4; p = 0.02 and 0.015, respectively). Bilaterality was seen less often in older compared with younger patients (8% [seven of 93] versus 26% [85 of 328]; p < 0.001). The most common diagnostic group was Grade 3 (by International Hip Dysplasia Institute classification), which included 58% (51 of 88) of all classified dislocated hips. Splintage was the primary initial treatment of choice at 80% (395 of 496), but was far more likely in younger compared with older patients (94% [309 of 328] versus 18% [17 of 93]; p < 0.001). CONCLUSIONS: With the lack of strong prognostic indicators for DDH identified to date, the center is an important variable to include as a potential predictor of treatment success or failure.

BACKGROUND: Femoroacetabular impingement is increasingly recognized as a cause of hip pain but its incidence after an innominate osteotomy for the correction of acetabular dysplasia has not been determined. This information would be essential for the orthopaedic surgeon because it has the potential to produce a poor outcome in the long term when trying to balance acetabular instability and overcorrection. QUESTIONS/PURPOSES: The purposes of our study were (1) to determine the frequency with which clinically relevant femoroacetabular impingement (FAI) occurs after an innominate osteotomy for the treatment of acetabular dysplasia; (2) to determine risk factors for the development of FAI; and (3) to compare postoperative radiographic and clinical outcomes in patients having undergone an innominate osteotomy for the correction of acetabular dysplasia both with and without FAI. METHODS: This was a retrospective review of 154 hips (132 patients) that had undergone an innominate osteotomy for acetabular dysplasia and were evaluated at a minimum followup of 10 years (mean = 12 years). Mean age at the time of surgery was 3 years, 114 hips had a concomitant open reduction, and 54 hips also had femoral shortening. One hundred eight hips had a Salter osteotomy and 46 had a Pemberton osteotomy. Radiographs were analyzed to determine the lateral center-edge angle (CE angle) and the presence of a crossover sign. The diagnosis of FAI was established when the CE angle was greater than 40 degrees , there was a positive crossover sign, and the patient had groin pain when flexing the hip less than 90 degrees . Comparisons between nonparametric variables were performed with a Mann-Whitney's U test. Categorical variables were compared with a chi-square test. Change in acetabular index (correction) was dichotomized considering 20 degrees of correction as the cutoff point. Association is presented as odds ratio (95% confidence interval), and logistic regression was performed. RESULTS: According to our criteria, 18 of 154 hips had FAI (12%). Of the 18 patients with FAI, 10 had undergone a Pemberton osteotomy (10 of 46 [22%]) and eight a Salter osteotomy (eight of 108 [7%]). A change in the postoperative acetabular index greater than 20 degrees was associated with a greater likelihood of developing FAI. The mean postoperative acetabular index was lower for the group with FAI, for whom it was 20 degrees , compared with the group without FAI, for whom it was 27 degrees (p = 0.04). The mean Iowa Hip Score for the group with FAI was 85, whereas for those without FAI, it was 93 (p = 0.03). CONCLUSIONS: FAI is not common after an innominate osteotomy for the treatment of acetabular dysplasia; however, overcorrection is related to a higher incidence. When FAI is present, it can affect the outcome. Overcorrection should be avoided when performing an innominate osteotomy for the treatment of acetabular dysplasia because it can create iatrogenic FAI and have an adverse effect on outcome. LEVEL OF EVIDENCE: Level III, therapeutic study.

BACKGROUND: Redislocation after an open reduction for develpmental dislocation of the hip is relatively common. The purpose of this study was to determine if the use of a transarticular pin (TAP) is safe and effective in maintaining reduction. METHODS: A total of 578 patients (645 hips) were reviewed after an open reduction, mean age at the time of surgery was 2.1 years. In 621 cases a smooth Kirschner wire was placed across the joint. The rates of redislocation, avascular necrosis (AVN), and other complications were determined. AVN was classified according to Kalamchi et al. Outcome was determined at a minimum of 6 years using the Severin classification. RESULTS: Redislocation occurred in 27 cases (4.1% rate), 24 had a TAP (3.8%) and 3 did not (12.5%). AVN was observed in 127 cases (19.7%), it was type I in 73 cases, type II in 38 cases, type III in 14 cases, and type IV in 2 cases; AVN was seen in 123 cases which had a TAP (19.8%) and 4 cases which did not (16.7%). Analyzing pin placement: when it was in the inferior third of the neck the rate of AVN was 15.2% (32/211), in the middle third it was 21.7% (71/326), and in the superior third it was 28.6% (24/84). According to the Severin classification for the hips with a TAP, 496 were type I or II (79.8%), 113 were type III (18.2%), 10 were type IV (1.6%), and 2 were type V (0.3%); in the group without a TAP 19 cases were type I or II (79.2%), 4 were type III (16.7%), and 1 was type IV. CONCLUSIONS: The use of a TAP was effective in maintaining reduction and was not associated with significant morbidity. Placing the pin in the inferior third of the neck was associated with the lowest rate of AVN. LEVEL OF EVIDENCE: Level IV--therapeutic.

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.