https://www.selleckchem.com/products/nuciferine.html Two patients had open physes; the remainder had closing physes. 64% of patients had additional meniscal tears and 76% had bony contusions. The average duration of follow-up was 2.8years (range 2-5years). At final follow-up, there were no angular deformities or leg length discrepancies. The average quadriceps atrophy of the operative leg was 4mm. The average Lysholm score was 98. 86% of patients returned to sports. No patients had re-rupture of their operative ACL. No incidences of infections, numbness, or anterior knee pain were reported. Two patients had a second arthroscopy for re-injury, revealing new meniscal tears but intact ACL grafts. Use of quadriceps tendon autograft for ACL reconstruction in adolescent patients allows reliable return to sport with minimal complications. Level IV, retrospective case series. Level IV, retrospective case series.Fibrodyplasia ossificans progressiva (FOP) is a rare hereditary disease, which has a variable course characterized by occasional flare-ups of heterotopic ossification (HO) in soft tissues that are followed by swelling, stiffness, pain and warmth. Here, we report for the first time a case of a 45-year-old female patient with known FOP recovering from COVID-19 with disease progression potentially linked with the viral illness. In December 2020 the patient contracted a mild form of COVID-19 infection without need for hospital admission. Since January 2021, the patient felt unwell, with occasional abdominal pain which progressively intensified. In March 2021 she presented with new onset of HO, complaining of pain, swelling and thickening sensation in the lower abdomen and left part of the neck. Computerized tomography (CT) and cytokine analysis were performed. CT scan revealed new heterotopic bone formation in multiple soft tissue areas of the neck indicating clear radiological progression. Radiotherapy, which has proven to be an efficient tool to control HO in this pati