Pablo Castañeda

Hemiepiphysiodesis for the Correction of Angular Deformity About the Knee

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, 24-52months). 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 − 13degrees. 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.

The natural history of osteoarthritis after a slipped capital femoral epiphysis/the pistol grip deformity.

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 Tönnis 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 Tönnis 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.

Functional outcome of stable grade III slipped capital femoral epiphysis treated with in situ pinning.

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. Level of evidence Level IV.

Interobserver and intraobserver reliability of the modified waldenström classification system for staging of legg-calvé-perthes disease

BACKGROUND The absence of a reliable classification system for Legg-Calvé-Perthes disease has contributed to difficulty in establishing consistent management strategies and in interpreting outcome studies. The purpose of this study was to assess interobserver and intraobserver reliability of the modified Waldenström classification system among a large and diverse group of pediatric orthopaedic surgeons. METHODS Twenty surgeons independently completed the first two rounds of staging: two assessments of forty deidentified radiographs of patients with Legg-Calvé-Perthes disease in various stages. Ten of the twenty surgeons completed another two rounds of staging after the addition of a second pair of radiographs in sequence. Kappa values were calculated within and between each of the rounds. RESULTS Interobserver kappa values for the classification for surveys 1, 2, 3, and 4 were 0.81, 0.82, 0.76, and 0.80, respectively (with 0.61 to 0.80 considered substantial agreement and 0.81 to 1.0, nearly perfect agreement). Intraobserver agreement for the classification was an average of 0.88 (range, 0.77 to 0.96) between surveys 1 and 2 and an average of 0.87 (range, 0.81 to 0.94) between surveys 3 and 4. CONCLUSIONS The modified Waldenström classification system for staging of Legg-Calvé-Perthes disease demonstrated substantial to almost perfect agreement between and within observers across multiple rounds of study. In doing so, the results of this study provide a foundation for future validation studies, in which the classification stage will be associated with clinical outcomes.

Strategies to Improve Nonoperative Childhood Management

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.

Feasibility and safety of perfusion MRI for Legg-Calvé-Perthes disease.

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-Calvé-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).

Varus-producing osteotomy for patients with lateral pillar type B and C Legg-Calvé-Perthes disease followed to skeletal maturity

PurposeWe 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.MethodsThis 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.ResultsA 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.ConclusionsWe found no statistically significant difference in the clinical or radiographic result for patients undergoing a VO compared to non-operative treatment.

Evaluation of Brace Treatment for Infant Hip Dislocation in a Prospective Cohort: Defining the Success Rate and Variables Associated with Failure.

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.

The safety and efficacy of a transarticular pin for maintaining reduction in patients with developmental dislocation of the hip undergoing an open reduction.

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.

How Often Does Femoroacetabular Impingement Occur After an Innominate Osteotomy for Acetabular Dysplasia

BackgroundFemoroacetabular 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/purposesThe 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.MethodsThis 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°, there was a positive crossover sign, and the patient had groin pain when flexing the hip less than 90°. 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° of correction as the cutoff point. Association is presented as odds ratio (95% confidence interval), and logistic regression was performed.ResultsAccording 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° 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°, compared with the group without FAI, for whom it was 27° (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).ConclusionsFAI 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 EvidenceLevel III, therapeutic study.