Pie Crust Technique of the Deep Medial Collateral Ligament in Knee Arthroscopy: Ultrasound and Anatomic Study.

This article determines compartment opening of the medial articular space of the knee after pie crust (PC) technique of the medial collateral ligament (MCL) by ultrasound measurements and anatomic dissection. This is a cadaveric study of 12 specimens. Four anatomic references were marked on the skin. Distances between the femur and tibia in the internal compartment at 30 degrees of flexion were obtained with ultrasound measurements in four situations: with and without applying valgus force both prior and after the PC technique. Ultrasound measurements of the medial articular compartment were made twice and mean value was calculated. An anatomical dissection was performed and distances between the puncture marks and the infrapatellar branch of the saphenous nerve was measured. Lilliefors test of normality was applied and variables were expressed as mean and standard deviation (SD). Qualitative variables were expressed by absolute frequencies and percentages. Statistical significance was a two-tailed p-value of < 0.05. Prior to the PC technique, mean (SD) distance between the femur and tibia in the medial compartment were 14.2 (4.0) mm in basal conditions and 17.1 (3.7) mm when applying valgus force (p = 0.003). PC technique increased the mean (SD) distance by 1.9 (1.9) mm under basal conditions (p < 0.01) and 2.9 (1.6) mm when applying valgus force (p < 0.01). The infrapatellar branches of the saphenous nerve were not damaged and the mean (SD) distance between the punctures and the nerve was 9.0 (3.3) mm. The PC is a reproducible, safe, and measurable surgical technique that opens controllably the medial compartment. PC as described avoided damage to the nerve branches.

Diagnostic efficacy of bone scintigraphy, magnetic resonance imaging, and positron emission tomography in bone metastases of myxoid liposarcoma.

Myxoid liposarcomas (MLS) have a tendency to metastasize to unusual sites. We report an unusual case of bone metastases not detected by bone scan and neither by fluorodeoxyglucose positron emission tomography (PET-FDG) and successfully identified with magnetic resonance imaging (MRI) in a patient with metachronic MLS. Histopathological examination of the primary tumor evidenced a tumor with unfavorable prognostic markers, and the biopsy of an iliac bone lesion confirmed the diagnosis of metastatic disease. On histological grounds, the tumor showed features of a more differentiated neoplasm without foci of round cells or necrosis in the latter. MRI allowed the identification of disseminated disease compared to computed tomography (CT) and PET scans. Thus, because of the heterogeneous histological features of MLS and the biological behavior of the disease, a combined approach of FDGPET-CT and MRI, may allow a more accurate staging of soft tissue sarcomas.