ABSTRACT
Background: Following first-time lateral patellar dislocation (FTLPD), most patients are treated conservatively, although 50% of patients will have recurrent dislocations. Typically, radiographs followed by CT and/or MRI are used to assist the clinician in determining treatment strategy and, combined with clinical findings, intraarticular free bodies (CT/MRI), significant medial patellofemoral ligament (MPFL) tear (MRI) and lateral displacement of the patella (CT) form relative indications for surgery. Methods: Radiographs, MRI and CT knee studies of 34 patients after lateral patellar dislocation (26 FTLPD) were evaluated for intraarticular free bodies, patellar/trochlear fracture, lateral femoral condyle compression, MPFL tear, tibial tuberosity-trochlear groove (TT-TG) distance, and surgery indications. Free bodies and fractures were also evaluated on knee radiographs. FTLPD was analyzed as a subgroup. Surgical indications were compared between imaging modalities. Results: Among FTLPD (26 patients); free bodies were identified in 13 and 19 patients using MRI and CT respectively, compared with 5 patients on radiographs; this was statistically significant. In 8 cases surgery was indicated based on MPFL tear (MRI) combined with lateral patellar displacement (CT). When MRI and CT results were combined, 21 of 26 patients had imaging indications for surgery compared to 13 and 19 patients based on the MRI or CT alone, respectively.CT was statistically better than MRI alone or MRI with radiographs in identifying patients requiring surgery. Conclusion: An MRI or CT study is warranted to determine the need for surgery. A second imaging study (different from the first) should be considered, if surgical indication was not established from the initial study or clinical presentation.
ABSTRACT
As the COVID-19 pandemic continues to evolve, different clinical manifestations are better understood and studied. These include various haematologic disorders that have been shown to be associated with increased morbidity and mortality. We studied the prevalence of one unusual manifestation, heparin-induced thrombocytopenia (HIT) and its clinical implications in patients who are severely ill with COVID-19 in a single tertiary centre in Israel. The presence of thrombocytopenia, disseminated intravascular coagulation (DIC) and HIT, and their association with clinical course and outcomes were studied. One-hundred and seven patients with COVID-19 were included. Fifty-seven (53.2%) patients developed thrombocytopenia, which was associated with the worst outcomes (ventilation, DIC and increased mortality). Sixteen (28.0%) patients with thrombocytopenia were positive for HIT, all of which were supported by extracorporeal devices. HIT was independently associated with ventilation days, blood product transfusions, longer hospitalisation and mortality.Platelet abnormalities and HIT are common in patients who are critically ill with COVID-19 and are associated with the worst clinical outcomes. The mechanisms underlying HIT in COVID-19 are yet to be studied; HIT may contribute to the dysregulated immunologic response associated with COVID-19 critical illness and may play a significant part in the coagulopathy seen in these patients. As many patients with COVID-19 require aggressive thromboprophylaxis, further understanding of HIT and the implementation of appropriate protocols are important.
