In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most common finding in the equine species, whereas in humans rice bodies due to rheumatoid arthritis are more frequent. Herein we report a third type of floating body inside the stifle of an adult draught horse stallion, in macroscopic appearance similar to articular rice bodies known in humans. As revealed by histologic examination, the two particles consist of polypoid degenerated structures derived from synovial villi. Their formation was probably induced by ischemia.
Animals ; Histocytochemistry/veterinary ; Horse Diseases/*pathology ; Horses ; Joint Loose Bodies/pathology/*veterinary ; Male ; Stifle/*pathology ; Synovial Membrane/*pathology

PURPOSE: To determine the magnetic resonance (MR) imaging characteristics of traumatic transient lateral dislocation of the patellae. MATERIALS AND METHODS: In eight patients (6 males, 2 females, mean age: 22.4 years) in whom transient lateral dislocation of the patella was diagnosed, the distinctive MR imaging findings reflecting known injury mechanism were retrospectively analyzed with regard to bone contusion, chondral defect, fracture, loose body, joint effusion, and the associated soft tissue abnormalities. RESULTS: All of eight patients had bone contusions in the lateral femoral condyle and medial facet of the patella, while in five, chondral defects were present in this latter region. In three patients, fractures of the on lateral femoral condyle (n=2) and medial facet of the patella (n=3) were noted, and in three others, loose bodies were noted. Joint effusion [simple effusion (n=4), lipohemarthrosis (n=3)] was observed in seven patients, and associated soft tissue injuries [to the medial patellar retinaculum (n=8), patellar tendon (n=2), and anterior cruciate ligament (n=1)] in eight. Patellar subluxation was found in seven. CONCLUSION: MR imaging is a useful technique for the diagnosis of traumatic lateral dislocation of the patella. The significant MR findings are bone contusion in the lateral femoral condyle and medial facet of the patella, chondral defect, fracture, joint effusion, injury to the medial patellar retinaculum, and patellar subluxation.
Anterior Cruciate Ligament ; Contusions ; Diagnosis ; Dislocations* ; Female ; Humans ; Joint Loose Bodies ; Joints ; Magnetic Resonance Imaging ; Male ; Patella* ; Patellar Ligament ; Retrospective Studies ; Soft Tissue Injuries

OBJECTIVETo summarize the techniques and evaluate the therapeutic effect of posterior fixation and fusion in the treatment of Os odontoideum complicated by atlantoaxial dislocation.

METHODSFrom March, 2007 to October, 2010, 10 patients with Os odontoideum (including 6 male and 4 female patients aged from 20 to 65 years, mean 39.8 years) were treated in our hospital. Before and after the operation, the patients underwent X ray, CT and MRI examinations to measure and evaluate the degree of dislocation and neural compression. After preoperative traction for 1-2 weeks, all the 10 patients showed deductible atlantoaxial dislocation. Through a posterior approach, Atlantoaxial pedicle screws fixation were performed in 9 cases, and C2/3 pedicle-Occiput screw fixation was performed in 1 case. All the patients wore cervical collars as external support for 3 months after the operation.

RESULTSThe mean operative time was 3 h in these patients with a mean intraoperative blood loss of 420 ml. The symptoms were relieved after the surgery in all the patients, who showed no neck pain or neurological defects. The patients were followed up for 6 to 52 months (mean 22 months), and bony fusion was observed in all the 10 cases within 6 to 8 months without such complications as internal fixation failure or redislocation of the atlas.

CONCLUSIONPatients with Os odontoideum complicated by atlantoaxial dislocation should undergo surgical stabilization to avoid severe neurological injury. Pedicle screw instrument in the atlas allows restoration of the spinal stability, short-segment fusion, and maximal preservation of the mobility of the neck.

Adult ; Aged ; Atlanto-Axial Joint ; injuries ; Bone Transplantation ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Joint Dislocations ; complications ; surgery ; Joint Loose Bodies ; complications ; surgery ; Male ; Middle Aged ; Odontoid Process ; pathology ; Spinal Fusion ; methods ; Treatment Outcome ; Young Adult

OBJECTIVETo investigate the role of Caspase-8 and Bcl-2 in the formation of loose bodies in Kashin-Beck disease (KBD).

METHODSSpecimens of cartilage loose bodies were collected from 50 adult patients with KBD, and the samples of articular cartilage were collected from 10 healthy adults to serve as control. Avidin-biotin alkaline phosphatase immunohistochemistry was employed to examine Bcl-2 and Caspase-8 positivities in the chondrocytes in the loose bodies.

RESULTSIn KBD loose bodies, the percentage of chondrocytes positive for Bcl-2 and Caspase-8 [(18.40∓8.78)% and (67.54∓12.29)%, respectively] were significantly higher than those of the control group [(12.25∓1.58)% and (24.70∓4.35)%, respectively]. Caspase-8 was found to promote chondrocyte apoptosis in the loose bodies, and this effect overrode the apoptosis-suppressing effect of Bcl-2. Bcl-2 and Caspase-8 positivities were found mainly in the deep hypertrophic chondrocytes in the cartilage or in cells adjacent to the bone tissues.

CONCLUSIONKBD loose bodies contain an increased percentage of apoptotic chondrocytes positive for Bcl-2 and Caspase-8. The apoptosis-inducing effect of Caspase-8 was a dominant feature in the cartilage pathology of KBD compared to the apoptosis-suppressing effect of Bcl-2.

Adult ; Apoptosis ; Cartilage ; pathology ; Case-Control Studies ; Caspase 8 ; metabolism ; Female ; Humans ; Joint Loose Bodies ; metabolism ; Kashin-Beck Disease ; metabolism ; pathology ; Male ; Middle Aged ; Proto-Oncogene Proteins c-bcl-2 ; metabolism