[Synovial cysts of unusual localization. 2 cases and review of the literature]. / Kystes synoviaux de topographie inhabituelle. Deux observations et revue de la littérature.

Two patients with true synovial cysts in atypical sites (internal compartment of knee and inguinal hollow) were investigated by radioarthrography, ultrasound and computed tomography imaging. The cyst in the hip region originated from a dilated serous bursa of the iliopsoas muscle that did not communicate or was no longer in communication with the joint. In contrast, the cyst of the knee appeared to be a lateral synovial capsule hernia. Positive diagnosis in both cases was dependent on combined ultrasound-CT scan imaging, this eliminating a tumor (sarcoma) of soft tissues. However, affirmation of the synovial origin (mesothelial covering of the wall) of the lesion was obtained by histology only, this allowing differentiation from a "capsular" (fibrous wall) cyst, which probably provokes similar ultrasound and CT scan images.

[The lateral atlantoaxial joint involvement in the rheumatoid arthritis. Report of ten cases and review (author's transl)]. / L'arthrite atloïdo-axoïdienne latérale au cours de la polyarthrite rhumatoide. A propos de dix observations.

An analysis of ten recent observations of lateral arthritis of C1-C2 during the course of rheumatoïd arthritis. This lesion, which is not rare, has charactéristic symptoms: localized pain together with occipital (Arnold's) neuralgia and specific blocking of head rotation towards the afflicted side. Frontal per-oral radiography shows joint line lesions most often unilateral, and a displacement of C1 towards the non afflicted side with pseudoinclination of the odontoïd process towards the afflicted side. Sometime more destructive lesions of the lateral masses of the atlas give them a triangular form and this may result eventually in an upwards "vertical" displacement of the odontoïd. The pain usually subsides in a few weeks after a conservative treatment with or without temporary immobilisation by a light removable cervical collar but the loss of the homolateral rotation of the head persists. Besides occipital (Arnold's) neuralgia, there seems to be no other neurologic complications; if they follow, it is due to an associated anteroposterior displacement.