Purpose: Simple bone cysts are among the most prevalent benign cystic tumor-like lesions in children. Proximal femoral simple bone cysts may require specific treatment because of increased fracture risk. With limited literature available on this specific localization, consensus regarding optimal treatment is lacking. We present a large international multicenter retrospective cohort study on proximal femoral simple bone cysts. Methods: All consecutive pediatric patients with proximal femoral simple bone cyst from 10 tertiary referral centers for musculoskeletal oncology were included (2000–2021). Demographics, primary treatment, complications, and re-operations were evaluated. Primary outcomes were time until full weight-bearing and failure-free survival. Results: Overall, 74 simple bone cyst patients were included (median age 9 years (range = 2–16), 56 (76%) male). Median follow-up was 2.9 years (range = 0.5–21). Index procedure was watchful waiting (n = 6), percutaneous procedure (n = 12), open procedure (n = 50), or osteosynthesis alone (n = 6). Median time until full weight-bearing was 8 weeks (95% confidence interval = 0.1–15.9) for watchful waiting, 9.5 (95% confidence interval = 3.7–15.3) for percutaneous procedure, 11 (95% confidence interval = −0.7 to 13.7) for open procedure, and 6.5 (95% confidence interval = 5.9–16.1) for osteosynthesis alone (p = 0.58). Failure rates were 33%, 58%, 29%, and 0%, respectively (p = 0.069). Overall failure-free survival at 1, 2, and 5 years was 77.8% (95% confidence interval = 68.2–87.4), 69.5% (95% confidence interval = 58.5–80.5), and 62.0% (95% confidence interval = 47.9–76.1), respectively. Conclusion: A preferred treatment for proximal femoral simple bone cysts remains unclear, with comparable failure rates and times until full weight-bearing. Watchful waiting may be successful in certain cases. If not feasible, osteosynthesis alone can be considered. Treatment goals should be cyst control, minimizing complications and swift return to normal activities. Therefore, an individualized balance should be made between undertreatment, with potentially higher complication risks versus overtreatment, resulting in possible larger interventions and accompanying complications. Level of evidence: Level IV, retrospective multicentre study

Previous studies indicated that hardware removal may lead to increased morbidity and therefore, at least in adults, remains questionable for certain indications. However, risks such as corrosion or local reactions may be less likely in younger patients with current, improved hardware materials. We sought to retrospectively determine complication rates of hardware removal in pediatric upper limb surgery, and establish potential risk factors for increased morbidity.All children and adolescents who underwent inpatient hardware removal under anesthesia after previous upper limb surgery between 2002 and 2016 were retrospectively evaluated. The following details were extracted at the latest follow-up: demographics, implant location, hardware material, duration of surgery, duration of hardware in situ, and any complications graded according to Goslings et al (grade 0–5) and Sink et al (grade 1–5), respectively. Correlations were calculated to establish potential relationships between specific outcome parameters (e.g., location, duration of surgery etc.) and complication grades.A total of 2089 children were evaluated of whom 317 patients with 449 interventions (mean age 9.4 years) fulfilled the inclusion criteria for this study. Overall, 203 K-wires (46%), 97 plates (22%), 102 external fixators (23%), 32 intramedullary nails (7%), 6 screws (1%), 4 cerclages (1%) and 1 pin (0.2%) were removed; most common locations were the forearm (34%) and humerus (24%). The mean duration of surgery was 40 minutes (± 50.9), mean time in situ was 194 days (± 319.6). Complication rates were low overall, with most being grade 0 (n = 372; 83%) or 1 (n = 60; 13%) according to Goslings et al and grade 1 (n = 386; 86%) and 2 (n = 42; 9%) according to Sink et al. No severe complications were observed. The following predictors were related to the severity of the complications in linear regression analysis: more distal localizations, external fixators, longer duration of surgery and female sex.Hardware removal under anesthesia in the pediatric upper extremity has produced a low complication rate with no severe complications and can thus be considered to be safe. Increased morbidity occurred in more distal localizations, external fixators, longer surgeries and females.Level of Evidence:Therapeutic, Level IV.

Background: This study examined the effect of the COVID-19 pandemic and the resulting decrease in the incidence of various categories of injuries, with the main focus on fractures and mild traumatic brain injuries in a paediatric population. Methods: This retrospective cohort study evaluated all children from 0 to 18 years of age presenting with an injury at the level 1 trauma centre of the University Clinic of Orthopaedics and Trauma Surgery in Vienna during the lockdown from 16 March to 29 May 2020 compared to records over the same timeframe from 2015 to 2019. Results: In total, 14,707 patients with injuries were included. The lockdown did not lead to a significant decrease in fractures but, instead, yielded a highly significant increase in mild traumatic brain injuries when compared to all injuries that occurred (p = 0.082 and p = 0.0001) as well as acute injuries (excluding contusions, distortions and miscellaneous non-acute injuries) (p = 0.309 and p = 0.034). Conclusions: The percentage of paediatric fractures did not decrease at the level 1 trauma centre, and a highly significant proportional increase in paediatric patients with mild traumatic brain injuries was observed during the COVID-19 lockdown. Therefore, medical resources should be maintained to treat paediatric trauma patients and provide neurological monitoring during pandemic lockdowns.

Background: Aneurysmal bone cysts (ABC) are rare benign cystic bone tumors, generally diagnosed in children and adolescents. Proximal femoral ABCs may require specific treatment strategies because of an increased pathologic fracture risk. As few reports are published on ABCs, specifically for this localization, consensus regarding optimal treatment is lacking. We present a large retrospective study on the treatment of pediatric proximal femoral ABCs. Methods: All eligible pediatric patients with proximal femoral ABC were included, from 11 tertiary referral centers for musculo-skeletal oncology (2000-2021). Patient demographics, diagnostics, treatments, and complications were evaluated. Index procedures were categorized as percutaneous/open procedures and osteosynthesis alone. Primary outcomes were: time until full weight-bearing and failure-free survival. Failure was defined as open procedure after primary surgery, >3 percutaneous procedures, recurrence, and/or fracture. Risk factors for failure were evaluated. Results: Seventy-nine patients with ABC were included [mean age, 10.2 (±SD4.0) y, n=56 male]. The median follow-up was 5.1 years (interquartile ranges=2.5 to 8.8). Index procedure was percutaneous procedure (n=22), open procedure (n=35), or osteosynthesis alone (n=22). The median time until full weight-bearing was 13 weeks [95% confidence interval (CI)=7.9-18.1] for open procedures, 9 weeks (95% CI=1.4-16.6) for percutaneous, and 6 weeks (95% CI=4.3-7.7) for osteosynthesis alone (P=0.1). Failure rates were 41%, 43%, and 36%, respectively. Overall, 2 and 5-year failure-free survival was 69.6% (95% CI=59.2-80.0) and 54.5% (95% CI=41.6-67.4), respectively. Risk factors associated with failure were age younger than 10 years [hazard ratios (HR)=2.9, 95% CI=1.4-5.8], cyst volume >55 cm³ (HR=1.7, 95% CI=0.8-2.5), and fracture at diagnosis (HR=1.4, 95% CI=0.7-3.3). Conclusions: As both open and percutaneous procedures along with osteosynthesis alone seem viable treatment options in this weight-bearing location, optimal treatment for proximal femoral ABCs remains unclear. The aim of the treatment was to achieve local cyst control while minimizing complications and ensuring that children can continue their normal activities as soon as possible. A personalized balance should be maintained between undertreatment, with potentially higher risks of pathologic fractures, prolonged periods of partial weight-bearing, or recurrences, versus overtreatment with large surgical procedures, and associated risks. Level of Evidence: Level IV, therapeutic study.

Background: The study purpose was to assess: (1) the complication rate of osteodistraction in the pediatric upper extremity, its severity and relation to patient-specific and treatment-specific parameters, and (2) dedicated patient-reported outcome scores after these procedures. Methods: This retrospective study analyzed a chart of patients undergoing osteodistraction of the upper limb between 2003 and 2020. Demographics, distraction-specific parameters, healing index, and any complications graded according to the Sink grading scale (grades 1 to 5) were extracted. An additional phone interview was performed to assess patient satisfaction and functionality of the elongated limb using the Quick-DASH (Disabilities of Arm, Shoulder, and Hand) score. Results: This study included 61 cases from 48 individual patients. The mean age at the start of distraction was 11.5±3.6 years. The ulna was the most frequently lengthened bone, with 21 (34.4%) cases. Ninety-four complications were observed, with an average complication rate of 77.0%. Based on the Sink grading scale (1 to 5), grade 3 complications were most common (n=29; 47.5%) followed by grade 1 (n=14; 23.0%), 2 (n=14; 23.0%), and 4 (n=4; 6.6%). A significantly lower and thus better bone healing index was observed for the age category less than 10 years compared with the 14 to 18 years group (P=0.006). The average satisfaction was 4.2±1.0 points of 5. The mean Quick-DASH score was 14.1±12.5, indicating very good clinical outcomes. Conclusions: Despite the occurrence of numerous complications, high patient satisfaction and good daily life functionality of the treated limb was observed. An age of more than 14 years at the beginning of therapy had a negative prognostic effect on bone healing during distraction. Thus, osteodistraction in the upper extremity may preferably be performed less than 10 years of age because of enhanced bone regeneration. Level of Evidence: Level IV—retrospective case series.