Scott Rosenfeld

Legg-Calvé-Perthes Disease: A Review of Cases with Onset Before Six Years of Age

BACKGROUND The prognosis for children in whom Legg-Calvé-Perthes disease develops before the age of six years was initially reported to be good, but later studies demonstrated a less favorable prognosis. To assess the natural history of this condition in this age group, we reviewed a large cohort of children who had received minimal treatment for the disease. METHODS The medical records and radiographs of all children with Legg-Calvé-Perthes disease seen at our institution between 1944 and 2000 were reviewed. The cases of 172 patients with a total of 188 affected hips were studied. The course of the disease and the final clinical and radiographic outcomes were evaluated in all patients. RESULTS Typical Legg-Calvé-Perthes disease was noted in 164 hips of 160 patients. According to the lateral patellar classification, seven of these hips were in group A; 101, in group B; twenty-seven, in the B/C border group; and twenty-nine, in group C. According to the Stulberg classification, there were 131 Class-I or II (good) results, fourteen Class-III (fair) results, and nineteen Class-IV (poor) results. The lateral pillar classification was highly correlated with the outcome, whereas treatment did not correlate with the outcome. Only lateral pillar group-B/C border and C hips with an onset of the disease between the ages of four years and five years and eleven months had a poor prognosis. We unexpectedly encountered a group of twelve patients with bilateral, simultaneous development of apparent Legg-Calvé-Perthes disease. In that group, there were twenty-one Stulberg Class-I or II (good), three Stulberg Class-III (fair), and no Stulberg Class-IV (poor) results, although fourteen of the twenty-four hips were in lateral pillar group C. The outcome in the hips in lateral pillar group C was significantly better when the patient had bilateral simultaneous involvement than when the patient had typical Legg-Calvé-Perthes disease. CONCLUSIONS The prognosis for patients with the onset of Legg-Calvé-Perthes disease before the age of six years is favorable, with 80% having a good result. Only children between the ages of four years and five years and eleven months with a B/C or C lateral pillar classification of involvement have a less favorable prognosis. Treatment was not found to influence outcome. Simultaneous bilateral disease, which had a more favorable prognosis, may represent a unique disorder.

Joint Effects of an Aldosterone Synthase (CYP11B2) Gene Polymorphism and Classic Risk Factors on Risk of Myocardial Infarction

BACKGROUND The -344C allele of a 2-allele (C or T) polymorphism in the promoter of the gene encoding aldosterone synthase (CYP11B2) is associated with increased left ventricular size and mass and with decreased baroreflex sensitivity, known risk factors for morbidity and mortality associated with myocardial infarction (MI). We hypothesized that this polymorphism was a risk factor for MI. METHODS AND RESULTS We used a nested case-control design to investigate the relationships between this polymorphism and the risk of nonfatal MI in 141 cases and 270 matched controls from the Helsinki Heart Study, a coronary primary prevention trial in dyslipidemic, middle-aged men. There was a nonsignificant trend of increasing risk of MI with number of copies of the -344C allele. However, this allele was associated in a gene dosage-dependent manner with markedly increased MI risk conferred by classic risk factors. Whereas smoking conferred a relative risk of MI of 2.50 (P=0.0001) compared with nonsmokers in the entire study population, the relative risk increased to 4.67 in -344CC homozygous smokers (relative to nonsmokers with the same genotype, P=0.003) and decreased to 1.09 in -344TT homozygotes relative to nonsmokers with this genotype. Similar joint effects were noted with genotype and decreased HDL cholesterol level as combined risk factors. CONCLUSIONS Smoking and dyslipidemia are more potent risk factors for nonfatal MI in males who have the -344C allele of CYP11B2.

Predicting the Presence of Adjacent Infections in Septic Arthritis in Children.

Background: The gold standard for treatment of septic arthritis is urgent surgical debridement. Preoperative magnetic resonance imaging (MRI) may identify osteomyelitis, subperiosteal abscesses, and intramuscular abscesses, which frequently occur with septic arthritis. If these adjacent infections are not recognized, initial treatment may be inadequate. The purpose of this study is to develop a prediction algorithm to distinguish septic arthritis with adjacent infections from isolated septic arthritis to determine which patients should undergo preoperative MRI. Methods: An IRB-approved retrospective review of 87 children treated for septic arthritis was performed. All patients underwent MRI. Sixteen variables (age, sex, temperature, WBC, CRP, ESR, ANC, hematocrit, platelet count, heart rate, systolic blood pressure, diastolic blood pressure, symptom duration, weight-bearing status, prior antibiotic therapy, and prior hospitalization) from admission were reviewed. Graphical and logistical regression analysis was used to determine variables independently predictive of adjacent infection. Optimal cutoff values were determined for each variable and a prediction algorithm was created. Finally, the model was applied to our patient database and each patient with isolated septic arthritis or adjacent infection was stratified based upon the number of positive predictive factors. Results: A total of 36 (41%) patients had isolated septic arthritis and 51 (59%) had septic arthritis with adjacent foci. Five variables (age above 3.6 y, CRP>13.8 mg/L, duration of symptoms >3 d, platelets <314×103 cells/&mgr;L, and ANC>8.6×103 cells/&mgr;L) were found to be predictive of adjacent infection and were included in the algorithm. Patients with ≥3 risk factors were classified as high risk for septic arthritis with adjacent infection (sensitivity: 90%, specificity: 67%, positive predictive value: 80%, negative predictive value: 83%). Conclusions: Age, CRP, duration of symptoms, platelet count, and ANC were predictive of adjacent infections. Patients who met ≥3 criteria are at high risk for adjacent infection and may benefit from preoperative MRI. Level of Evidence: Level III—retrospective comparative study.

Pediatric osteoarticular infection update.

Musculoskeletal infections are a common cause of morbidity in children. A multitude of studies over the past few years have improved our knowledge and understanding of the etiology, diagnosis, and treatment of pediatric osteomyelitis and septic arthritis. Staphylococcus aureus continues to be the most common pathogen; however, new and innovative organism identification techniques are improving the speed and accuracy of diagnosis and increasing the identification of other less common organisms. Improved capability for patient assessment with a combination of advanced imaging studies and timely laboratory tests allow for a more thorough understanding of the disease process and more efficient patient care.

Orthopedic perspective on selected pediatric and adolescent knee conditions

As arthroscopy advances and more children are involved in sporting activities, a new field of pediatric sports medicine is emerging. This paper reviews the diagnosis and treatment aspects of three pediatric knee conditions often encountered in the care of skeletally immature patients. We specifically address anterior cruciate ligament injuries, osteochondritis dessicans and discoid meniscus. Representative cases with images and arthroscopic correlation are included.

Acute traumatic rupture of the patellar tendon in pediatric population: Case series and review of the literature

BACKGROUND Intact knee extensor mechanism is required for the normal function of the lower extremity. Patellar tendon rupture is a relatively rare injury with peak age incidence around 40 years and usually occurs midsubstance. The occurrence of pure patellar tendon rupture without bony avulsion is an extremely rare injury in the pediatric population with few cases reported in the literature with limited information regarding frequency, complications, and outcomes in children. However, due to increased participation in sports and high-energy recreational activities during childhood, the frequency of such injuries has progressively increased. OBJECTIVE To evaluate the frequency of pediatric patellar tendon rupture injuries and describe the radiological findings, treatment modalities, and outcome of such injuries. METHODS Demographic and clinical data on a series of patients who sustained patellar tendon rupture were reviewed. These data included age at time of injury, sex, laterality, mechanism of injury, associated injuries, complications, presence or absence of Osgood-Schlatter disease, diagnostic imaging such as plain radiographs and magnetic resonance images (MRI), surgical technique, method of fixation, period of postoperative immobilization, total duration of physiotherapy, time to return to sports activities and follow-up duration. Insall-Salvati ratio was calculated on the preoperative lateral x-ray. The functional outcome was evaluated with regard to final knee active range of motion (AROM), manual quadriceps muscle testing, and presence or the absence of terminal extension lag. Clinical outcome rating using knee society score (KSS) was performed and functional outcome was further classified according to the calculated score. RESULTS Five male patients with patellar tendon rupture (7%) were identified among 71 pediatric patients who sustained acute traumatic injury of the knee extensor mechanism. The mean age at the time of injury was 13.6 years (range: 12-15 years). The injury occurred in relation to sports activities in 4 patients. Osteogenesis imperfecta and Osgood-Schlatter disease were identified in 2 patients. High riding patella is the hallmark diagnostic sign detected in plain x-ray with preoperative Insall-Salvati ratio ranged from 1.7 to 2.5. Three patients had pure soft tissue avulsion distally from the proximal tibia, 1 patient had pure soft tissue avulsion proximally from the inferior patellar pole, and 1 patient with midsubstance tendinous disruption. No associated intra-articular lesions were identified. Suture bridge double row technique, transpatellar suturing, and transosseous suturing through the proximal tibia were used for patellar tendon reinsertion. After a mean follow-up period of 18. 4 weeks (range: 10-30 weeks), patients achieved AROM ranging from 0 to 120° to 0-137° without terminal extension lag. The mean time to return to sports activity was 22 weeks (range: 13-30 weeks). Quadriceps muscle strength was 5/5 at the final follow-up visit in all patients; however, relative muscle atrophy was noted in comparison to the other side in one patient. The mean KSS was 91.8 points (range: 79-100 points) with excellent outcome in 4 patients and good outcome in 1 patient. CONCLUSION Patellar tendon rupture is rare in the pediatric population and represents 7% of pediatric patients who sustained acute traumatic injury of the knee extensor mechanism. Ruptures may occur midsubstance, or from proximal or distal insertions. High riding patella is the hallmark diagnostic sign for such injury. Although rare, it is considered a serious injury that necessitates early diagnosis and surgical intervention. Functional range of motion was obtained in all patients with different modalities of treatment.

Orthopedic perspectives on femoroacetabular impingement

Femoroacetabular impingement (FAI) is a cause of hip pain in which there is abnormal and repetitive contact between the proximal femur and the acetabulum. FAI can occur as a primary condition in children with distinct anatomical abnormalities or can occur as a secondary process in cases of developmental hip conditions or trauma. There are two main categories of FAI, cam and pincer, which are distinguished based on whether the anatomical abnormality is on the femoral side or the acetabular side of the hip joint, respectively. Good outcomes have been achieved with early surgical intervention, but once advanced degenerative changes have occurred the chances for a successful surgical outcome are severely diminished. The orthopedic surgeon’s ability to appropriately treat FAI depends on an accurate understanding of the etiology and features of each child. The ability to make an early, accurate diagnosis is enhanced with the use of imaging modalities such as radiographs, MRI and CT. This review will focus on orthopedic perspectives in the use of these imaging modalities in defining the anatomical features of and guiding treatment for FAI.

Patient Factors Associated With Methicillin-Resistant Staphylococcus aureus Septic Arthritis in Children

Staphylococcus aureus is the most common causative organism in pediatric septic arthritis, with methicillin-resistant Staphylococcus aureus (MRSA) being responsible for a significant portion of these infections. Early identification and initiation of proper treatment may improve outcomes by minimizing potential morbidity. The purpose of this study was to identify variables obtained on initial patient presentation associated with MRSA septic arthritis. Sixteen factors were retrospectively evaluated in 109 consecutive pediatric patients diagnosed with culture-confirmed septic arthritis. Graphical and logistical regression analyses were employed to determine factors independently predictive of MRSA septic arthritis. Twenty-seven (25%) patients had MRSA and 82 (75%) had non-MRSA septic arthritis. C-reactive protein of 13.7 mg/L or greater, duration of symptoms of 4 days or more, heart rate of 126 beats per minute or greater, and absolute neutrophil count of 8.72×103 cells/µL or greater were associated with MRSA septic arthritis. Ultimately, 98% of patients with 1 or no risk factors had non-MRSA and 96% of patients with MRSA septic arthritis had 2 or more positive risk factors. Elevated C-reactive protein, duration of symptoms, heart rate, and absolute neutrophil count are predictive of MRSA infection in the setting of pediatric septic arthritis and can be obtained on initial evaluation. In patients for whom there is concern for MRSA infection, this may guide more expedient treatment, such as early initiation of contact precautions and appropriate antibiotic therapy before culture results become available. [Orthopedics. 2018; 41(2):e277-e282.].

Validating an Algorithm to Predict Adjacent Musculoskeletal Infections in Pediatric Patients With Septic Arthritis

Background Septic arthritis is frequently associated with adjacent infections including osteomyelitis and subperiosteal and intramuscular abscesses. While often clinically indiscernible from isolated septic arthritis, the diagnosis of adjacent infections is important in determining the need for additional surgical intervention. MRI has been used as the diagnostic gold standard for assessing adjacent infection. Routine MRI, however, can be resource-intensive and delay surgical treatment. In this context, there is need for additional diagnostic tools to assist clinicians in determining when to obtain preoperative MRI in children with septic arthritis. In a previous investigation by Rosenfeld et al., an algorithm, based on presenting laboratory values and symptoms, was derived to predict adjacent infections in septic arthritis. The clinical applicability of the algorithm was limited, however, in that it was built from and applied on the same population. The current study was done to address this criticism by evaluating the predictive power of the algorithm on a new patient population. Questions/purposes (1) Can a previously created algorithm used for predicting adjacent infection in septic arthritis among pediatric patients be validated in a separate population? Methods Records for all pediatric patients (1-18 years old) surgically treated for suspected septic arthritis during a 3-year period were retrospectively reviewed (109 patients). Of these patients, only those with a diagnosis of septic arthritis confirmed by synovial fluid analysis were included in the study population. Patients without confirmation of septic arthritis via synovial fluid analysis, Gram stain, or culture were excluded (34 patients). Patients with absence of MRI, younger than 1 year, insufficient laboratory tests, or confounding concurrent illnesses also were excluded (18 patients), resulting in a total of 57 patients in the study population. Five variables which previously were shown to be associated with risk of adjacent infection were collected: patient age (older than 4 years), duration of symptoms (> 3 days), C-reactive protein (> 8.9 mg/L), platelet count (< 310 x 103 cells/µL), and absolute neutrophil count (> 7.2 x 103 cells/µL). Adjacent infections were determined exclusively by preoperative MRI, with all patients in this study undergoing preoperative MRI. MR images were read by pediatric musculoskeletal radiologists and reviewed by the senior author. According to the algorithm we considered the presence of three or more threshold-level variables as a “positive” result, meaning the patient was predicted to have an adjacent infection. Comparing against the gold standard of MRI, the algorithm’s accuracy was evaluated in terms of sensitivity, specificity, positive predictive value, and negative predictive value. Results In the new population, the sensitivity and specificity of the algorithm were 86% (95% CI, 0.70-0.95) and 85% (95% CI, 0.64-0.97), respectively. The positive predictive value was determined to be 91% (95% CI, 0.78-0.97), with a negative predictive value of 77% (95% CI, 0.61-0.89). All patients meeting four or more algorithm criteria were found to have septic arthritis with adjacent infection on MRI. Conclusions Critical to the clinical applicability of the above-mentioned algorithm was its validation on a separate population different from the one from which it was built. In this study, the algorithm showed reproducible predictive power when tested on a new population. This model potentially can serve as a useful tool to guide patient risk stratification when determining the likelihood of adjacent infection and need of MRI. This better-informed clinical judgement regarding the need for MRI may yield improvements in patient outcomes, resource allocation, and cost. Level of Evidence Level II, diagnostic study.

Kocher Criteria Revisited in the Era of MRI: How Often Does the Kocher Criteria Identify Underlying Osteomyelitis?

Background: The Kocher criteria are established clinical parameters that predict hip septic arthritis (SA) with a 93% or greater positive-predictive value when 3 or 4 variables are present. The incidence of osteomyelitis (OM) in these patients has not been reported. The purpose of this study is to evaluate the incidence of OM in patients who have 3 or 4 positive Kocher criteria. Methods: A total of 71 consecutive patients (mean age, 4.7 y) treated between January 2007 and July 2013 for suspected hip SA who had 3 or 4 positive Kocher criteria were retrospectively reviewed. The Kocher criteria variables include: non–weight-bearing status, fever>38.5°C, white blood cell>12 K, and erythrocyte sedimentation rate>40 mm/h. All patients underwent ultrasound (US) and magnetic resonance imaging as part of their workup. Results: There were a total of 71 patients with 3 or 4 positive Kocher criteria. Of these, 22.5% (n=16) had a diagnosis of SA and 47.9% (n=34) had a diagnosis of OM. Of the 71 patients, 52.1% (37/71) had a hip effusion on US. When an effusion was identified, 18.9% (7/37) had isolated SA, 18.9% (7/37) had isolated OM, and 24.3% (9/37) had combined SA and OM. When no effusion was identified, a total of 18/34 (52.9%) had underlying OM. Conclusions: Patients with 3 or 4 Kocher criteria have a high incidence (47.9%) of OM. Even in patients with a hip effusion on US, the incidence of OM was equal to that of SA. These results suggest that the combination of Kocher criteria and US alone is not sufficient to make a diagnosis in patients presenting with hip irritability and consideration should be given to adding magnetic resonance imaging to their workup. Level of Evidence: Level III—retrospective chart review.