Abstract
Purpose: In 15 previously healthy cases who developed osteonecrosis, 4 months after Covid, 14 primary, 1 secondary), we prospectively addressed 2 hypotheses. First, Covid-19-associated coagulopathy superimposed on underlying previously undiagnosed familial thrombophilia-hypofibrinolysis leads to development of severe multifocal osteonecrosis (Ficat Stage III-IV ON 0.25-12 months after Covid-19). Second, joint pain can be relieved and joint collapse prevented by anticoagulation (Xarelto or Eliquis) before joint collapse in osteonecrosis with underlying familial coagulopathies.
Basic Procedure: Thrombophilia-hypofibrinolysis measures in 15 cases were compared to 110 healthy controls and to 235 patients with primary osteonecrosis without Covid.
Main Findings: Post-Covid osteonecrosis developed in both hips- all 15 cases, both knees-4 cases, multifocal- 4 cases. Four months (median) post- Covid, all 30 hips were painful, 10 Ficat stage I,10 II, 6 III, and 4 IV. Cases were more likely to have Factor V Leiden heterozygosity, (4/15 [27%] than controls (2/109 (2%) (p=.002) and primary ON cases (21/235 (9%) (p<.05. Cases were more likely (6/15, 40%) to have V Leiden and/or Prothrombin G20210A heterozygosity than both 3/110 (3%) healthy controls (p=.0001). and 30/231 (13%) primary ON cases, p=.012. In 9 cases, of 18 joints Ficat stage I or II pre-anticoagulation, given Eliquis or Xarelto for 1 year (median), 0/18 joints collapsed, pain resolved joints- 6 cases), and improved (6 joints- 3 cases).
Principal Conclusions: Post-Covid osteonecrosis joint pain should trigger evaluation for underlying familial coagulopathies, and consideration of anticoagulation in early primary osteonecrosis (Ficat stages I-II).
New-Important: Anticoagulation before osteonecrosis joint collapse in post Covid patients with familial coagulopathies can relieve pain and prevent joint collapse.