Catcher's Knee: Posterior Femoral Condyle Juvenile Osteochondritis Dissecans in Children and Adolescents.

BACKGROUND: Juvenile osteochondritis dissecans is an idiopathic condition involving subchondral bone and articular cartilage in skeletally immature patients in whom the growth plates are open, potentially leading to lesion instability. Because of the differing forces experienced by baseball/softball catchers versus position players, the age at which lesions develop and the characteristics of the lesions themselves may differ between these 2 populations. The purpose of the study was to examine relative age and characteristics of osteochondritis dissecans (OCD) knee lesions in catchers compared with position players. METHODS: Using a text-based search tool that queries clinic notes and operative reports, computerized medical records from 1990 to 2014 from the Sports Medicine Program of a tertiary care Children's Hospital were searched to find children and adolescents who had OCD of the knee, played baseball/softball, had a specified field position, and had magnetic resonance imaging of the knee. Ultimately, 98 knees (78 patients) were identified: 33 knees (29 patients) in catchers and 65 knees (49 patients) in noncatchers. Data collected included position played (catcher/noncatcher), demographics (age, unilateral/bilateral, and sex), lesion severity, and sagittal and coronal lesion location. RESULTS: When compared with noncatchers, catchers presented at a younger age (P=0.035) but were similar with respect to bilateral involvement (P=0.115), sex (P=0.457), and lesion severity (P=0.484). Lesions in catchers were more posterior on the femoral condyle in the sagittal plane (P=0.004) but similar in location in the coronal plane (P=0.210). CONCLUSIONS: Catchers developed OCD at a younger age and in a more posterior location on the medial and lateral femoral condyles than noncatchers. These results may represent the effects of repetitive and persistent loading of the knees in the hyperflexed position required of catchers. Increased awareness of this risk may lead to surveillance and prevention programs. LEVEL OF EVIDENCE: Level III-case-control study.

Metallosis Presenting as a Progressive Neurologic Deficit Four Years After a Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis: A Case Report.

STUDY DESIGN: A case report. OBJECTIVE: The aim of this study was to report a case of progressive pain and paraparesis secondary to metallosis four years after a pediatric posterior spinal fusion (PSF). SUMMARY OF BACKGROUND DATA: Metallosis as a late complication of pediatric spinal surgery is rarely reported. Myelographic computed tomography (CT) can be helpful in establishing the diagnosis. The use of serum chromium levels as a means of definitive diagnosis has been suggested, but has only been reported retrospectively. METHODS: A 19-year-old male presented four years after PSF for adolescent idiopathic scoliosis with sudden onset of pain and neurologic deficits. Radiographs and CT scan suggested infection. Intraoperatively, no purulent material was noted, but black and yellowish corrosive debris was found around the right L1 pedicle screw, so it was removed and the cavity packed with tobramycin impregnated calcium sulfate beads. After surgery, neurologic deficits worsened. CT myelogram showed irregular opacification of the thecal sac at the level of the conus. A posterior laminectomy and decompression was performed with removal of all debris and spinal instrumentation. Metallosis within the spinal canal was noted and serum chromium levels were obtained. RESULTS: The patient was discharged one week after admission with improvement of pain and gradual improvement in neurologic examination. Three years postdischarge, the patient is asymptomatic and examination shows bilateral clonus. Serum chromium levels declined from a high of 4.5 µg/L operatively to 0.8 at final follow-up (normal: 0.2-0.6 µg/L). CONCLUSION: Although uncommon, metallosis should be considered in the differential diagnosis of any late presenting case of pain, infection-like symptoms, or neurologic deficits after pediatric PSF. CT myelography and serum chromium levels may help guide diagnosis; however, surgical exploration is needed for definitive diagnosis and treatment. LEVEL OF EVIDENCE: 4.

Earlier time to reduction did not reduce rates of femoral head osteonecrosis in pediatric hip fractures.

OBJECTIVES: Hip fractures account for less than 1% of all pediatric fractures; however, femoral head osteonecrosis (ON) after this injury ranges from 0% to 92%. The aim of this investigation was to add our experience to the literature and identify factors that may increase or decrease the risk of ON in pediatric patients with hip fractures. DESIGN: Institutional review board-approved retrospective review. SETTING: Pediatric level II trauma center. PATIENTS/PARTICIPANTS: Two hundred fifty-five pediatric hip fracture cases were reviewed from 1983 to 2009. Children were excluded if they had metabolic bone disease, subtrochanteric or pathologic fractures, slipped capital femoral epiphysis, or less than 1 year follow-up. This left 43 patients with 44 fractures in the study. INTERVENTION: Standard fixation procedures. MAIN OUTCOME MEASUREMENTS: Factors that could influence ON were analyzed and included age, Delbet classification, displacement, time to reduction, reduction quality and type, and whether a decompression was performed. Fisher exact tests were used with P <0.05 considered statistically significant. RESULTS: Of the 44 cases included in the study, 9 (20%) developed ON. Age ≥11 years was the only statistically significant independent predictor of ON (P = 0.04). The details of 3 unique cases are also presented. CONCLUSIONS: The rate of ON in this case series was 20%. No ON occurred in any child <11 years old. We were unable to demonstrate that earlier time to reduction reduced the incidence of ON. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

A prospective comparison of computer-navigated and fluoroscopic-guided in situ fixation of slipped capital femoral epiphysis.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is usually treated with percutaneous in situ screw fixation to prevent further progression of deformity. The purpose of this investigation is to compare computer navigation (CN) techniques with traditional fluoroscopic (fluoro) techniques for in situ fixation of SCFE. METHODS: This study was an IRB-approved prospective study of 39 hip pinnings in 33 children. CN techniques were used in 22 cases and fluoro in 17. The CN and fluoro groups were statistically similar in terms of grade and acuity of the slip. Children were assigned to the groups based on the intraoperative imaging technique used by the attending on call, with 3 surgeons in each group taking equal amounts of call. The "approach-withdraw" technique was used in all cases. Postoperative limited-cut, reduced-dose computed tomography (CT) scans were obtained to evaluate screw placement. This included blinded analysis for screw penetration of the joint, screw tip-to-apex distance, the distance the screw passed to the center of the physis, and attainment of center-center position. The number of pin passes, intraoperative radiation exposure, and operating room (OR) time were also analyzed. Statistics used included ANOVA, the χ and median tests. RESULTS: Compared with the fluoro group, CN resulted in more accurate screw placement. There was 1 case of joint penetration in the fluoro group not appreciated intraoperatively but detected on postoperative CT. CN also resulted in statistically significant (P < 0.05) reduced screw tip-to-apex distance and distance to the center of the physis. There was no statistically significant difference between the 2 groups in attainment of the center-center position, number of pin passes, or intraoperative radiation exposure. OR time averaged 19 minutes longer in the CN group. There was no case of avascular necrosis or chondrolysis in either of the groups. CONCLUSIONS: Compared with traditional fluoro techniques, CN in situ fixation of SCFE results in more accurate screw placement, comparable number of pin passes and intraoperative radiation exposure, and increased OR time. The cost-benefit ratio of this technology requires careful consideration at each individual institution. LEVEL OF EVIDENCE: II.

Clinically suspected scaphoid fractures in children.

PURPOSE: Scaphoid fractures are often missed in children because of their rarity and difficulty with radiographic diagnosis. Children are often treated for clinically suspected scaphoid fractures although there is no radiographic evidence for fracture on initial evaluation. The 2-fold purpose of this study is (1) to determine how many clinically suspected pediatric scaphoid fractures later became radiographically evident fractures and (2) to identify physical examination findings that suggest a scaphoid fracture when present at initial evaluation. METHODS: We performed separate retrospective and longitudinal reviews of children younger than 16 years referred to orthopaedics with traumatic wrist pain from January 1995 to April 2002. A total of 104 cases with high clinical suspicion but no radiographic evidence of scaphoid fracture on initial examination were included. Patients were followed until discharge to determine if they later demonstrated a confirmed fracture. In the longitudinal arm, 7 specific examination findings were recorded. Simple and multiple logistic regressions were used to analyze the data. RESULTS: Thirty-one (30%) of the 104 wrists with no initial radiographic evidence of fracture had a radiographically evident scaphoid fracture at follow-up. In the longitudinal arm (n = 41), the following 3 findings were statistically significant predictors of scaphoid fracture: volar tenderness over the scaphoid (P = 0.010), pain with radial deviation (P = 0.001), and pain with active wrist range of motion (P = 0.015). Presence of any of these findings was associated with a higher likelihood of scaphoid fracture. CONCLUSION: A high percentage (30%) of clinically suspected scaphoid fractures in children became radiographically evident fractures at follow-up. Volar scaphoid tenderness, radial deviation pain, and pain with active wrist range of motion can be used as signs to increase suspicion for eventual fracture. We recommend that all clinically suspected pediatric scaphoid fractures be immobilized with repeat radiographs and a clinical examination at 2 weeks. LEVEL OF EVIDENCE: II.

Delayed union and nonunion following closed treatment of diaphyseal pediatric forearm fractures.

Delayed unions and nonunions of diaphyseal pediatric forearm fractures are exceedingly uncommon. In the past they generally have been reported in conjunction with open fracture or initial operative management of these fractures. The authors report six cases that occurred in low-energy, closed fractures initially managed with casting. The cases all occurred in teenage patients from age 13 to 16, and all cases involved the ulna. The mid-diaphysis was the most common location, and this may represent a watershed zone of perfusion with a relatively poor intraosseous blood supply. All of these patients were managed with compression plating with or without bone grafting. Three of these patients had rapid healing in an average of 2 months, while one had an inadequate radiographic record and another was lost to follow-up. The other patient had a more prolonged course to healing after surgery.