Superior dislocation of the patella: a pathognomonic finding and review of literature.

A 59-year-old woman with a painful right knee that became locked in extension after a trivial trauma was seen at the emergency room. This was caused by unloaded hyperextension in bed. She was diagnosed with a superior dislocation of the patella. A closed reduction was performed, but a recurrent episode was seen within a week. An arthroscopy was performed, in which the causative osteophytes were removed. In the 12-month follow-up after treatment, no recurrence was seen. A superior dislocation of the patella is caused by patellofemoral osteophytes that interlock. This can cause a degenerative knee to become locked in extension. Beside interlocking osteophytes of the patella and the distal femur, the superior part of the patella is tilted away from the femur. This is caused by the pull of the patella tendon and the simultaneous relaxation of the quadriceps tendon. This is a pathognomonic finding on radiographs that, to the best of our knowledge, has been identified but not been appreciated as such in previous reports. As illustrated in this report, a superior dislocation of the patella can easily be recognized on physical examination and radiographic imaging alone when familiar with the specific abnormalities. This will reduce unnecessary diagnostic imaging studies and delay in treatment. This case report illustrates a recurrent case of superior dislocation of the patella. We summarize and evaluate previous reports, discuss trauma mechanisms, physical examination, classification, and treatment including recurrent cases. After reading this case report the reader will be able to diagnose a superior dislocation of the patella with near certainty on physical examination and radiographic imaging of the knee alone.

Different susceptibility of osteosarcoma cell lines and primary cells to treatment with oncolytic adenovirus and doxorubicin or cisplatin.

Despite improvements in treatment regimens for osteosarcoma (OS) patients, survival rate has not increased over the last two decades. New treatment modalities are therefore warranted. Preclinical results with conditionally replicative adenoviruses (CRAds) to treat OS are promising. One type of CRAd that was effective against OS cells is Ad5-Delta24RGD. In other types of cancer, CRAds have been shown to interact synergistically with chemotherapeutic agents. Chemotherapy for OS often includes doxorubicin and cisplatin. Therefore, we explored combination treatment of OS cell lines and primary OS cell cultures with Ad5-Delta24RGD and doxorubicin or cisplatin. On OS cell lines, combination treatment was additive to synergistic. Surprisingly, however, on seven of eight primary OS samples no such combination effects were observed. In contrast, in many cases chemotherapy even inhibited CRAd-mediated cell killing. The inhibitory effect of doxorubicin on Ad5-Delta24RGD in primary OS cells appeared to correlate with slow cell growth rate; reduced viral replication and absence of chemotherapy-induced G2 cell cycle arrest. Our results point to the possibility that, at least for OS, virotherapy and chemotherapy should best not be performed simultaneously. In general, our work underscores the importance of testing new genetic anticancer agents and treatment regimens on primary cancer specimens.

[A missed unstable cervical vertebra fracture in a patient with ankylosing spondylitis]. / Een niet-herkende instabiele cervicale wervelfractuur bij een patient met de ziekte van Bechterew.

A 53-year-old man with a 13-year history ofankylosing spondylitis presented to the emergency clinic of another hospital because of neck pain after a fall from a low stepladder. The patient was put at ease and discharged after physical examination and X-ray of the cervical spine revealed nothing out of the ordinary. Because his neck pain persisted, the patient contacted his rheumatologist. New cervical X-rays revealed fractures of the body and articular process of CVI and CVII. The patient was referred to our hospital for orthopaedic treatment. The fractures healed during 2.5 months' treatment with halotraction and a halovest. All patients with ankylosing spondylitis with neck pain after trauma have an unstable cervical fracture until proven otherwise. Cervical fractures should be excluded in all cases and other diagnostic tools (CT-scan or MRI) must be used whenever necessary.