An Unusual Cause Of Knee Pain Impacting An ICU Nurse’s Ability To Run For Codes

Abstract

History: A 49 yo active female ICU nurse who enjoys hiking presented with right achy knee pain that hadstarted 6 months prior, but worsened 3 months ago when she twisted her knee playing with her nephewin the pool. The pain was worse with prolonged time on her feet preventing her from exercising andimpacting her ability to work, particularly running to code blues. She also noted pain in her distal thighand intermittent swelling with increase in venous distension. PHYSICAL EXAMINATION:Right Knee examAppearance: No skin abnormalities. Mild varum deformity. Small effusion. Gait: Antalgic Palpation: Lateral joint line tenderness to palpation Range of motion: Normal range of motion, pain with flexion. Meniscal testing: Positive McMurray’s, Thessaly, and bounce test. Ligament testing: Negative Lachman’s, anterior drawer, posterior drawer. Pain but no laxity with varusstress at 30 degrees. Patellar testing: Positive inhibition Strength/Function: 5-/5 quadriceps strength DIFFERENTIAL DIAGNOSIS:1. Meniscal tear 2. Venous thromboembolism 3. Malignancy 4. Osteoarthritis Tests/Results:XR 3V Right Knee:There are small spurs along the lateral and patellofemoral compartment. The joint spaces are normal.There is a small right effusion. There is a 2.4 cm focus of ill-defined sclerosis in the distal femoral shaft.This was not evident on the comparison study. MRI Right Knee without Contrast:There is a distal femoral metaphyseal lesion with chondroid matrix measuring 28 mm. There is a 2 mmextraosseous component anteriorly at the prefemoral fat pad.There is a T2 hyperintense focus in the proximal fibula which may represent a intraosseous ganglionversus an additional small cartilaginous lesion. FINAL DIAGNOSIS:Chondrosarcoma of the femur TREATMENT/OUTCOMES:The patient was referred to Orthopedic Oncology. Follow-up CT scan of the femur and chest showed nometastasis. The patient’s case was reviewed with the medical tumor board and she was scheduled fordistal femur replacement.