Secondary osteonecrosis of the knee as a part of long COVID-19 syndrome: a case series.

COVID-19 infection affects different organ systems with long-term sequelae, which has been termed as long COVID-19 syndrome. To the best of our knowledge, osteonecrosis of the knee as a part of long COVID-19 syndrome has not been documented. Corticosteroids are being used extensively in moderate and severe cases of COVID-19. We report two cases who developed osteonecrosis of the knee after being treated for COVID-19 infection. In our case series, the mean cumulative dose of prednisolone was 1156.5 mg (900-1413 mg), which is less than the cumulative dose reported in literature for osteonecrosis of the knee. In our case series, the patients developed symptomatic osteonecrosis at a mean interval of 73 days after initiation of steroid therapy, with the earliest presenting at 25 days. Early diagnosis of osteonecrosis of the knee on high clinical suspicion by MRI would help in early intervention with bisphosphonate therapy.

Avascular necrosis as a part of 'long COVID-19'.

'Long COVID-19' can affect different body systems. At present, avascular necrosis (AVN) as a sequalae of 'long COVID-19' has yet not been documented. By large-scale use of life-saving corticosteroids in COVID-19 cases, we anticipate that there will be a resurgence of AVN cases. We report a series of three cases in which patients developed AVN of the femoral head after being treated for COVID-19 infection. The mean dose of prednisolone used in these cases was 758 mg (400-1250 mg), which is less than the mean cumulative dose of around 2000 mg steroid, documented in the literature as causative for AVN. Patients were symptomatic and developed early AVN presentation at a mean of 58 days after COVID-19 diagnosis as compared with the literature which shows that it generally takes 6 months to 1 year to develop AVN post steroid exposure.

Patellar clunk syndrome in a current high flexion total knee design.

This retrospective study of 208 (204 patients) total knee arthroplasties evaluated the incidence of patellar clunk syndrome for two high-flex posterior stabilized knee prostheses; a high-flex fixed bearing prosthesis and a high-flex mobile bearing prosthesis. Patients were followed for up to two years and were evaluated for patellar clunk and component position. Knees receiving the mobile bearing had a significantly higher (p < 0.001) incidence of patellar clunk (15%) than knees receiving the fixed bearing (0%). There was a significantly higher incidence of patellar clunk in males (34.1%; p < 0.01) compared to females (8.6%). Fibrous nodules were treated surgically in 11 of the knees with patellar clunk. The design of this particular mobile bearing knee seems to contribute to patellar clunk syndrome.

Posttraumatic pseudoaneurysm of popliteal artery following total knee arthroplasty.

We report a case of posttraumatic false aneurysm of popliteal artery after a total knee arthroplasty in an 82-year-old woman. This case is characterized by the distinct history of trauma to the popliteal fossa in the immediate postoperative period and the location of false aneurysm. In addition, the clinical symptoms were similar to those of deep vein thrombosis. The ultrasonographic examination and computed tomography (CT) angiography confirmed the diagnosis on 6(th) day after the surgery. Ultrasonographic examination 1 day later revealed no increase in the size of false aneurysm. She was treated with open surgical repair. Presenting the difficulty in the diagnosis, unusual location, etiology, and its management is the intention of this case report.