Localization and Likelihood of Chondral and Osteochondral Lesions After Patellar Dislocation in Surgically Treated Children and Adolescents.

Background: Patellar dislocation is a common injury in children and adolescents. There is a lack of information about concomitant osteochondral lesions in these patients. Hypothesis: We hypothesized that the likelihood of chondral or osteochondral lesions would increase with each prior patellar dislocation and that the appearance of lesions in surgically treated children and adolescents would be influenced by age, sex, injury mechanism, and body mass index (BMI). Study Design: Case-control study; Level of evidence, 3. Methods: Inclusion criteria were (1) age <18 years, (2) surgical treatment with diagnostic arthroscopy of the knee including description of chondral and osteochondral lesions, and (3) maximum time period between the last patellar dislocation and presentation in our department of 6 weeks and maximum of 4 weeks between presentation and surgery. A total of 153 children (173 knees) with a mean age of 13.0 ± 2.1 years were included. All surgical reports and intraoperative arthroscopic imaging were analyzed retrospectively for the location and severity of lesions. The likelihood of lesions was calculated with multiple stepwise regression models regarding injury mechanism, number of dislocations, sex, age, physeal closure, and BMI. Results: The regression model to predict femoral lesions was statistically significant (χ2[5] = 26.55; P < .001) and identified male sex, BMI ≥25, traumatic injury mechanism, and physeal closure as independent factors associated with the appearance of femoral lesions. The second regression model predicting the appearance of patellar lesions was also statistically significant (χ2[4] = 26.07; P < .001) and identified the traumatic injury mechanism as a single independent predictor for patellar lesions. Conclusion: BMI ≥25, male sex, and physeal closure were factors significantly associated with femoral chondral and osteochondral lesions in our cohort. In case of traumatic lateral patellar dislocation (LPD), the likelihood of patellar and femoral chondral and osteochondral lesions is significantly higher than in nontraumatic LPD. Early magnetic resonance imaging and surgical treatment should be considered in obese patients, male patients, and patients with physeal closure and after traumatic LPD.

Safety and performance of biodegradable magnesium-based implants in children and adolescents.

AIMS: Biodegradable magnesium-based alloy implants represent a promising option in orthopedic surgery, as the clinical outcomes have been reported to be comparable to those of titanium implants and no surgical interventions are required for removal. To date, little is known about the results of the use of these implants in children and adolescents. Therefore, the aim of the present study was to analyze the safety and performance of these implants in children and adolescents. PATIENTS AND METHODS: Eighty-nine patients treated with magnesium-based implants for fracture stabilization, osteotomy and osteochondral refixation were analyzed; 38 were treated by osteosynthesis; 18, osteotomy; and 33, osteochondral refixation. The mean follow-up duration was 8.2 months (range, 1.5-30 months). Clinical and radiographical follow-up examinations were performed at 4-8 weeks and 3-6 months, respectively, to evaluate implant performance and osseous consolidation. RESULTS: Clinical outcomes were rated as good to very good in all patients. Radiolucent zones were apparent after surgery in all patients but were noted to decrease in size during the follow-up period. Revision surgery was necessary in 1 of 89 patients who had a highly unstable osteochondritis dissecans lesion of the knee. None of the magnesium-based implants required surgical removal. CONCLUSION: Magnesium-based implants in children and adolescents results in good clinical outcomes when used for fracture stabilization, osteotomy and osteochondral defect refixation. Future studies are needed to further analyze the significance of the transient appearance and temporal development of radiolucent zones in the growing skeleton as well as the long-term performance of these implants.

Electromagnetic navigation reduces radiation exposure for retrograde drilling in osteochondrosis dissecans of the talus.

BACKGROUND: Retrograde drilling in osteochondrosis dissecans (OCD) is a widely used surgical intervention. A radiation-free electromagnetic navigation system (ENS)-based method was compared with the standard freehand fluoroscopic (SFF) method regarding clinical applicability. METHODS: We performed a clinical cohort study at a department of Orthopaedics in a Level 1 children's hospital with 40 patients (20 SFF and 20 ENS). Retrograde drilling of the talar dome was used in patients with unstable medial OCD (MRI stage 2 according to Hepple's revised classification; stage 2 according to the International Cartilage Repair Society). The outcome measurements were: (a) Intraoperative fluoroscopy exposure and length of surgery and (b) Postoperative serial follow-up MRIs every 6 months. RESULTS: 22 female and 18 male patients aged 13.8 ± 1.6 years (range: 11-17 years) were included. Using the ENS technique, length of surgery was significantly reduced to 20.2 ± 6.4 min compared to 36.1 ± 11.8 min (p < 0.01) for the SFF technique. The average x-ray radiation time for the SFF technique was 23.5 ± 13.5 sec and 1.9 ± 1.7 sec for the ENS technique (p < 0.01). Radiation exposure was significantly reduced from 44.6 ± 19.7 mSv (SFF technique) to 5.6 ± 2.8 mSv (ENS technique) (p < 0.01). Intraoperative perforation of cartilage occurred once in the SFF group. Correct placement of the drilling channel was verified in all patients on follow-up MRI after six months and a timely healing was seen after two years. CONCLUSIONS: The ENS method provides for a significant reduction in length of surgery and radiation exposure. ENS was without intraoperative cartilage perforation. The clinical and radiological follow-up parameters are comparable for SFF- and ENS-guided retrograde drilling. TRIAL REGISTRATION: WF - 085/20, 05/2020 "retrospectively registered" https://www.aerztekammer-hamburg.org/ethik_kommission.html .

Fixation of Unstable Osteochondritis Dissecans Lesions and Displaced Osteochondral Fragments Using New Biodegradable Magnesium Pins in Adolescents.

OBJECTIVE: Fixation of unstable osteochondritis dissecans (OCD) lesions and displaced osteochondral fragments are frequently performed procedures in pediatric orthopedic surgery. Since 2018, CE-certified MAGNEZIX pins are used in our institution in these cases. The aim of this study was (1) to analyze safety, efficiency, and limitations of magnesium-pin-based fixation of unstable OCD lesions and displaced osteochondral fragments and (2) to report clinical and radiological outcomes at short-term follow-up (FU). DESIGN: In this prospective cohort study, 19 patients (10 girls and 9 boys) were included. Inclusion criteria were (1) magnetic resonance imaging-confirmed unstable OCD lesion or displaced osteochondral fragment, (2) fixation with magnesium-based pins, and (3) minimum FU of 6 months. X-rays were taken 6 weeks and 6 months after operation and magnetic resonance imaging scans every 4 to 6 months to assess the healing progress. RESULTS: In total 67 pins were used, with a mean of 3.6 ± 1.4 per patient. Average age at surgery was 13.7 years (11-17 years). Mean time of operation was 56 ± 31 minutes, including arthroscopy, fixation, and patellar realignment (n = 6). No intraoperative complications occurred. Average FU was 11.3 ± 4.2 months (6-20 months). No redislocation or new dislocation occurred. Until now a complete radiographic healing occurred in 12 cases. Due to an implant failure in one case 11 weeks after the index surgery a revision became necessary. CONCLUSIONS: In short-term FU of 11 ± 4 months MAGNEZIX pins provide high stability after fixation of unstable OCDs and displaced osteochondral fragments leading to uncomplicated and timely healing.

Validity of Ultrasound Compared with Magnetic Resonance Imaging in Evaluation of Osteochondritis Dissecans of the Distal Femur in Children.

OBJECTIVE: Magnetic resonance imaging (MRI) is currently the gold standard to diagnose and monitor osteochondritis dissecans (OCD) of the knee. The purpose of this study was to evaluate for the first time if ultrasound imaging can be used to visualize osteochondritis dissecans of the distal femur. DESIGN: From May 2008 to December 2013, 44 children (26 boys and 18 girls) presenting with OCD of the knee in our department were examined and evaluated by ultrasound imaging. Mean age at diagnosis was 11.8 ± 2.2 years. Two independent experienced orthopedic surgeons analyzed the localization, stage, and the size of the OCD via ultrasound and compared the results with the MRI findings. RESULTS: Ultrasonic examination has limitations in assessing the OCD stage I and therefore is not suitable for evaluating this stage of the disease. In stages II to IV, a good correlation to MRI regarding defect localization and size can be found, when the defect is localized in a region that is accessible to ultrasonic examination. CONCLUSION: Ultrasonic scan is an appropriate tool for the screening and monitoring of OCDs stages II to IV. It provides an inexpensive and readily available alternative to MRI. In addition, the healing process of higher grade defects as well as the screening of the opposite side can also be performed by ultrasound. Detection of defects being localized close to the intercondylar notch or far posterior on the lateral condyle are limitations for the use of ultrasound.

Vertical Expandable Rib-based Distraction Device for Correction of Congenital Scoliosis in Children of 3 Years of Age or Younger: A Preliminary Report.

BACKGROUND: This study was designed to evaluate the treatment outcome of very young children with congenital scoliosis aged 3 years or under after surgery with a vertical expandable prosthetic titanium rib (VEPTR)-based distraction device. METHODS: A retrospective study of 13 children undergoing implantation of a vertical expandable rib-based distraction device. From September 2007 to June 2018, 13 children (7 male and 6 female patients) with congenital scoliosis were followed after treatment with a VEPTR. The outcome parameters were complications, thoracic height, kyphosis, lordosis, and coronal major scoliosis curve. In addition, the American Society of Anaesthesiologists (ASA) score, assisted ventilation rating, and hemoglobin and body mass index were analyzed. Data were examined separately by 2 investigators. RESULTS: The mean age at initial surgical treatment was 24.4±10.6 months, follow-up was 91.5±23.1 months. The mean number of surgical procedures per patient was 14±3.9 (total 182 operations). Apart from planned operations every 6 months, 5 unplanned operations (2.7%) were performed. The major scoliosis curve improved significantly from 55.2±21.9 degrees to 40.5±18.7 degrees, thoracic spine height T1-T12 significantly from 111±12 mm to 137±23 mm, T1-S1 height significantly from 211±13 mm to 252±36 mm and space available for the lung from 80.9%±11.3% to 84.4%±8.8% (preoperatively and at 5-y follow-up, respectively). Kyphosis increased significantly from 30±21.4 degrees to 42.6±23.5 degrees and lordosis from 32.4±20.9 degrees to 37.6±10.4 degrees. Hemoglobin levels were virtually unchanged. Weight increased from 10.6±2.8 kg to 20.2±5.0 kg at final follow-up, but body mass index decreased from 16.6±3.7 kg/m² to 15.7±2.9 kg/m². CONCLUSIONS: The expandable rib-based distraction device is an effective method to treat severe congenital scoliosis in very young children. It can control the deformity and promotes spinal and thoracic growth. LEVEL OF EVIDENCE: Level IV.