Walter P. Samora

Juvenile osteochondritis dissecans of the knee: predictors of lesion stability.

Background: Recent data suggest magnetic resonance imaging (MRI) is the best method to analyze the status of the cartilage and subchondral bone in patients with juvenile osteochondritis dissecans (JOCD). Methods: MRI analysis of 122 knees and 132 JOCD lesions in 109 patients who underwent arthroscopic treatment for osteochondritis dissecans lesions of the knee between March 2003 and January 2011. Results: Agreement between MRI and arthroscopic grading was 62.1%. MRI sensitivity was 92% and specificity was 55%. Positive predictive value of MRI was 33% and negative predictive value of MRI was 97%. In a multivariable logistic regression model, the odds of a unstable lesion on the lateral femoral condyle nonweight-bearing location were 15.7 times greater than the odds of an unstable lesion on the medial femoral condyle weight-bearing area (95% confidence interval: 2.6-95.7, P=0.003.) The odds of the lateral femoral condyle weight-bearing lesion having an unstable grade were also greater than for a medial femoral condyle weight-bearing lesion, but the results were not statistically significant (odds ratio, 1.70, P=0.349). Conclusions: A high T2 signal retrograde to the lesion may commonly appear with an early, stable arthroscopic grade lesion. MRI continues to be reliably sensitive to JOCD lesions and a good predictor of low-grade, stable lesions. However, MRI predictability of high-grade, unstable JOCD lesions is less reliable. Lesions in atypical locations, such as the nonweight-bearing surface of the lateral femoral condyle, more commonly present as higher, arthroscopic grade lesions. Level of Evidence: Level IV, retrospective case series.

Meniscus tears in children.

Increased athletic participation by the skeletally immature athlete and a heightened suspicion by physicians have contributed to an increase in the incidence of meniscal injuries in children and adolescents. In young patient, meniscal injury could have long-term consequences, so an understanding of recognition and treatment is essential. We review the anatomy and development of the menisci, review classification and diagnosis of meniscal tears, discuss management options and outcomes of treatment, and focus on discoid lateral meniscus and meniscal cysts.

Discoid Meniscus: Diagnosis and Management

Discoid lateral meniscus is a common abnormal meniscal variant in children. Detailed history and physical examination combined with an MRI of the knee predictably diagnose a discoid meniscus. The clinical presentation varies from being asymptomatic to snapping, locking, and causing severe pain and swelling of the knee. Because of the pathologic anatomy and instability, discoid menisci are more prone to tearing. Treatment options for symptomatic patients vary based on the type of anomaly, the age of the patient, stability, and the presence or absence of a tear. Improvements in arthroscopic equipment and technique have resulted in good to excellent short-term outcomes for saucerization and repair.

A preliminary study of volatile agents or total intravenous anesthesia for neurophysiological monitoring during posterior spinal fusion in adolescents with idiopathic scoliosis.

Study Design. A prospective randomized controlled trial. Objective. The purpose of this study was to prospectively compare the efficacy of neurophysiological monitoring during general anesthesia with either a total intravenous technique or with the volatile anesthetic agent, desflurane. Summary of Background Data. A total intravenous anesthetic technique is generally chosen when neurophysiological monitoring is used as it has been shown to facilitate such monitoring. Despite this, with prolonged infusions of propofol, prolonged awakening times may be seen, which may impact the time required for postoperative neurological assessment or more importantly result in significant delays, should a wake-up test become necessary. To date, there are no prospective trials comparing intravenous techniques with a volatile agent–based anesthetic technique and its effects on neurophysiological monitoring. Methods. This prospective study compares somatosensory evoked potential and motor evoked potential monitoring during posterior spinal fusion in 30 adolescents. The patients were randomized to receive a total intravenous technique with propofol-remifentanil or a volatile agent–based technique with desflurane-remifentanil. Results. The groups were similar with regard to age, weight, height, body mass index, Cobb angle, and distribution of Lenke classifications. No differences were noted in anesthesia time, surgery time, intraoperative fluids, or estimated blood loss between the 2 groups. Time to eye opening, time to following commands, and time to tracheal extubation were shorter in the volatile anesthesia group than the total intravenous anesthesia group. No clinically significant difference was noted in the amplitude or latency of somatosensory evoked potential monitoring. Although statistically significantly greater voltage amplitude was required to generate a motor evoked potential, the voltage amount was within a clinically acceptable range. Conclusion. Our data demonstrate that a volatile agent–based anesthetic regimen is feasible even during neurophysiological monitoring. Advantages include a more rapid awakening and the feasibility of a rapid wake-up test (<5 min) in the event that irreversible changes in neurophysiological monitoring are noted. Level of Evidence: 2

Submuscular bridge plating for length-unstable, pediatric femur fractures.

Background: Submuscular bridge plating has become an acceptable method of treatment for pediatric femur fractures. The purpose of our study was to describe a technique for submuscular bridge plating and review a series of consecutive, length-unstable, pediatric femur fractures treated at a single institution with this technique. Methods: We performed a query of hospital records from January 4, 2006, to May 10, 2011, to identify length-unstable femur fractures treated with submuscular bridge plating by 5 pediatric surgeons. Included were patients treated with submuscular bridge plating for a femur fracture. Excluded were patients with incomplete medical records, inadequate radiographs, or follow-up <6 months duration. Fifty-one patients met diagnostic criteria; 19 patients were excluded due to incomplete medical records and/or radiographs. Results: The study cohort included 32 patients with 33 femur fractures. There were 15 left femurs and 18 right femurs, including 1 bilateral fracture patient. Fracture pattern was composed of 13 comminuted, 5 spiral, 9 long oblique, and 6 short oblique. Mechanisms of injury included: fall from height (8), recreation (23), and MVA (2). Mean time for full weightbearing was 8.1 weeks (range, 3 to 17.6 wk). All patients were radiographically healed by their 12-week assessment. There were no intraoperative complications. Implant removal occurred in 26 patients. There were 2 cases of a broken screw discovered upon implant removal. The remnant screw was not removed in either case. The mean follow-up time for those with implant removal was 43.6 weeks (range, 27 to 83 wk). The 11 patients without implant removal had a mean follow-up time of 38.6 weeks (range, 31.6 to 50 wk). There were no cases of varus or valgus malalignment >10 degrees. One patient experienced implant irritation. There were no cases of wound infections. Conclusions: Our technique of surgical intervention has simplified both implantation and removal, and produced comparable and excellent healing rates, low complication rates, and early return to full weightbearing. Level of Evidence: Level IV, case series.

Weight-bearing osteochondral lesions of the lateral femoral condyle following patellar dislocation in adolescent athletes.

In patients with patellar dislocation, osteochondral injury is often an indication for early surgical intervention. However, no studies have identified a relationship between injury to the weight-bearing surface of the lateral femoral condyle following a patellar dislocation and the eventual need for surgical treatment. The authors hypothesized that a significant number of patients sustain injury to the weight-bearing surface of the lateral femoral condyle following an acute patellar dislocation.Radiographs and magnetic resonance images were retrospectively reviewed and the patterns of injury were evaluated for 80 patients with a diagnosis of acute patellar dislocation, including the presence of osteochondral damage, the location of the medial patellofemoral ligament injury, and concomitant meniscal pathology. Magnetic resonance imaging identified a 27.5% incidence of osteochondral injury involving the articular, weight-bearing region of the lateral femoral condyle following an acute lateral patellar dislocation. Surgical intervention was performed in more than 60% of these injuries, and most were not identified with plain radiographs. Injury to the weight-bearing surface of the lateral femoral condyle following patellar dislocation was 3.6 times more common in boys in the current study population.Osteochondral injury to the weight-bearing surface of the lateral femoral condyle may occur in a high percentage of patients following a lateral patellar dislocation and in a higher percentage of boys than girls. Patients with tenderness over the lateral femoral condyle following an acute lateral patellar dislocation should undergo magnetic resonance imaging.

Prevalence of Bilateral JOCD of the Knee and Associated Risk Factors

Purpose: Juvenile osteochondritis dissecans (JOCD) of the knee affects cartilage and subchondral bone surface. Multifocal JOCD is described as multiple lesions within the knee or presence of lesions in other joints. The true prevalence of bilaterality of JOCD is unknown. The purpose of this study is to determine the prevalence of bilateral JOCD and to identify potential risk factors for bilateral disease. Methods: We evaluated 108 consecutive patients presenting for JOCD at a single pediatric hospital system. If an OCD lesion of the knee was found, contralateral knee x-rays were performed. Lesion location was documented according to Cahill and Berg, magnetic resonance imaging (MRI) grading documented according to Dipaola, and if surgical treatment was undertaken, intraoperative grading performed according to Guhl. Patients with unilateral JOCD were compared with those with bilateral disease. Statistical analysis of categorical data was performed utilizing likelihood ratio &khgr;2 test or Fisher exact test and continuous data compared using nonparametric Wilcoxon 2-sample test. Results: There were 85 male (79%) and 23 females (21%) with an average age of 12.3 years (range, 6 to 18 y). Sixty-three percent of lesions were located on the medial femoral condyle and 33% on the lateral femoral condyle. Ninety percent of all lesions were considered weight-bearing lesions. Eighty percent were considered stable on MRI evaluation. Of those lesions that underwent surgical intervention, 61% were either grade I or II lesions. Seventy-three of 108 patients (68%) underwent some form of surgical intervention. Thirty-one patients (29%) were found to have contralateral JOCD lesions. Thirty-nine percent of contralateral lesions found on contralateral radiographs were asymptomatic at presentation and nearly all of those evaluated with MRI (16 of 18) were stable. Sixty-nine percent of contralateral lesions were located on the medial femoral condyle, 27% on the lateral femoral condyle, and 94% were considered weight-bearing lesions. Twelve of 31 contralateral lesions (39%) underwent surgical intervention. Comparing patients with unilateral and bilateral disease, female patients (P<0.05) and younger age at presentation (P<0.009) were risk factors for bilateral JOCD. No statistical difference among other variables was seen with regard to location, MRI or operative stability of lesion, or presence of symptoms. Conclusions: In our consecutive series of 108 patients with JOCD, we found a 29% incidence of bilateral disease. Almost 40% of contralateral lesions were asymptomatic upon presentation. Female sex and younger age at presentation were significant risk factors for bilateral disease. Lesion location, stability, and pain were not statistically significant variables. The authors recommend bilateral radiographic knee evaluation for all patients found to have JOCD. Level of Evidence: Level IV—retrospective case series.

Intercondylar Roof Inclination Angle: Is It a Risk Factor for ACL Tears or Tibial Spine Fractures?

Background: The relationship between the angle of inclination of the intercondylar roof [roof inclination angle (RIA)] and likelihood of knee injury has not been previously investigated in children. Methods: Twenty-five skeletally immature patients with a tibial spine fracture were age matched (±1 y) and sex matched with 25 patients with an anterior cruciate ligament (ACL) tear and with 50 control knees (2 for each patient). Demographic and diagnostic information was collected, and radiographic measurements were performed on notch and lateral radiographs of the knee. Results: Patients with a tibial spine fracture had an increased RIA compared with controls and patients with an ACL tear. Patients with ACL tears had a steeper notch roof, as indicated by a decreased RIA when compared with controls and patients with tibial spine fractures. Conclusions: Our results demonstrated that a decreased RIA was associated with ACL tear and that an increased RIA was associated with tibial spine fracture. Level of Evidence: Level III—prognostic.

A Prospective, Open-Label Trial of Clevidipine for Controlled Hypotension During Posterior Spinal Fusion

OBJECTIVES Controlled hypotension is one means to limit or avoid the need for allogeneic blood products. Clevidipine is a short-acting, intravenous calcium channel antagonist with a half-life of 1 to 3 minutes due to rapid metabolism by non-specific blood and tissue esterases. To date, there are no prospective evaluations with clevidipine in the pediatric population. We prospectively evaluated the dosing requirements, efficacy, and safety of clevidipine for ontrolled hypotension during spinal surgery for neuromuscular scoliosis in the pediatric population. METHODS Patients undergoing posterior spinal fusion for neuromuscular scoliosis were eligible for inclusion. The study was an open label, observational study. Maintenance anesthesia included desflurane titrated to maintain a bispectral index at 40 to 60 and a remifentanil infusion. Motor and somatosensory evoked potentials were monitored intraoperatively. When the mean arterial pressure (MAP) was ≥ 65 mmHg despite remifentanil at 0.3 mcg/kg/min, clevidipine was added to maintain the MAP at 55 to 65 mmHg. Clevidipine was initiated at 0.25 to 1 mcg/kg/min and titrated up in increments of 0.25 to 1 mcg/kg/min every 3 to 5 minutes to achieve the desired MAP. RESULTS The study cohort included 45 patients. Fifteen patients (33.3%) did not require a clevidipine infusion to maintain the desired MAP range, leaving 30 patients including 13 males and 17 females for analysis. These patients ranged in age from 7.9 to 17.4 years (mean ± SD: 13.7 ± 2.2 years) and in weight from 18.9 to 78.1 kg (mean ± SD: 43.4 ± 14.2 kg). Intraoperatively, the clevidipine infusion was stopped in 6 patients as the surgeon expressed concerns regarding spinal cord perfusion and requested a higher MAP than the study protocol allowed. The data until that point were included for analysis. The target MAP was initially achieved at a mean time of 8.9 minutes. Sixteen of the 30 patients (53.3%) achieved the target MAP within 5 minutes. Heart rate (HR) increased from a baseline of 83 ± 16 to 86 ± 15 beats per minute (mean ± SD) (p=0.04) with the administration of clevidipine. No patient had a HR increase ≥ 20 beats per minute or required the administration of a β-adrenergic antagonist. The duration of the clevidipine administration varied from 8 to 527 minutes (mean ± SD: 160 ± 123 minutes). The maintenance infusion rate of clevidipine varied from 0.25 to 5.0 mcg/kg/min (mean ± SD: 1.4 ± 1.1 mcg/kg/min). Clevidipine was paused a total of 43 times in the 30 cases. In 18 of the 30 patients (60%), the clevidipine infusion was temporarily paused more than once due to a MAP < 55 mmHg. A fluid bolus was administered to only 1 patient to treat the low MAP. No patient required the administration of a vasoactive agent for hypotension. When the clevidipine infusion was discontinued as controlled hypotension was no longer required, the MAP returned to baseline or ≥ 65 mmHg within 10 minutes in 12 of the 30 patients (40%). CONCLUSIONS Clevidipine can be used to provide controlled hypotension during posterior spinal fusion. The response of the MAP, both the onset and duration of action, were rapid. Although titration of the infusion with occasional pauses of administration may be needed, excessive hypotension was not noted.

Is there still a place for cast wedging in pediatric forearm fractures

Background: Forearm fractures are common skeletal injuries in childhood and can usually be treated nonoperatively with closed reduction and casting. Trends toward increasing operative treatment of these fractures have emerged. We aim to demonstrate the safety and efficacy of cast wedging for treatment of pediatric forearm fractures. Methods: We performed a prospective chart review of patients with forearm fractures, including distal radius (DR) fractures, treated with cast wedging at a single large pediatric hospital from June 2011 to September 2012. Inclusion criteria specified open distal radial physis, closed injury, loss of acceptable reduction, and availability of clinical and radiographic data from injury to cast removal. Exclusion criteria included pathologic fractures, neurovascular injury, fracture dislocations, open fractures, and closed DR physis. Reductions were performed and patients followed according to standard protocol at our institution, including placement into long-arm casts, initial follow-up visit within 5 to 10 days postinjury, and weekly visits for 2 weeks thereafter. If alignment were deemed unacceptable within 3 weeks of injury, cast wedging was utilized. Radiographic measurements of alignment included both radius and ulna on the injury film, postreduction, prewedge, postwedge, and final films. Radiographic technique was standardized, with repeatability testing demonstrating a precision of ±2 degrees. Results: Over 15 months, our hospital treated 2124 forearm or DR fractures with closed reduction and casting. There were 60 fractures treated either with percutaneous fixation (36) or open treatment (24). A total of 79 forearm or DR fractures were treated with cast wedging secondary to loss of reduction, of which 70 patients had complete clinical and radiographic data. Average age was 8.4 years (range, 3 to 14 y), with 25 females and 45 males. Significant improvement in angulation for both-bone forearm fracture from prewedge to final films was seen in 69 children, with no major complications. One patient failed wedging and required surgical reduction and fixation. Conclusions: Cast wedging is a simple, safe, noninvasive, and effective method for treatment of excessive angulation in pediatric forearm fractures. Level of Evidence: Level IV.