A patient in the 70s burdened with obesity, diabetes and arterial hypertension, on 29 May 2019 she underwent left hip arthroplasty, due to hip osteoarthritis. The postoperative course was uneventful, the patient was monitored twice in the outpatient clinic, 6 weeks after the operation and 6 months after the operation. The patient had no family or genetic risk factors for the coagulation system.
In March 2021, the patient began to report shortness of breath and cough. After conducting virological diagnostics (PCR), she was diagnosed with COVID-19 infection. Due to increasing dyspnea and respiratory disorders, she was hospitalized in one of the reference hospitals. Treatment was implemented in accordance with the applicable guidelines, i.e. a prophylactic dose of anticoagulants (nodraparinum 0.6 ml 1x1 s.c.), oxygen therapy and steroid therapy. During her stay, she began to complain of pain in the left hip and in the lumbosacral region, despite of the lack of direct trauma in this area. Clinical examination revealed no active extension of the right knee joint and numbness of the right thigh; the patient was diagnosed with paresis of the left femoral nerve. Intended for outpatient treatment, where, after neurological consultation and imaging tests (USG, CT, MRI), a hematoma (127x79x51 mm) was diagnosed in the pelvis (Fig. 1). Direct pressure from the hematoma on the femoral nerve was found. In imaging exams the nerve was swollen, indicating its damage.
In April 2021, the patient was admitted to the Centre of Postgraduate Medical Education, Gruca Teaching Hospital in Otwock in order to look for the diagnosis. On admission, all laboratory parameters [morphology, CRP, renal and hepatic parameters as well as parameters of the coagulation (PT 13.8 s, APTT 28.1 s, INR 1.04)] were normal. The patient discontinued to receive a prophylactic dose of anticoagulants. After re-neurological consultation, weakness of the left hip joint flexion and lack of active extension of the left knee joint, decreased tension of the quadriceps muscle of the thigh (1 in the Lovette scale), decreased superficial sensation on the anterior and medial surface of the thigh and the medial surface of the shin were found. Due to the lack of a suitable device, it was not possible to perform an EMG examination during hospitalization. Further imaging exams showed decreasing of the hematoma size (approx. 62 x 26 x 28 mm).
The patient was qualified for conservative treatment. Physical therapy and rehabilitation were implemented. The patient underwent control Doppler ultrasound examinations in order to exclude venous thrombosis of the lower limbs, no thrombotic changes were found in any of the exams. Low molecular weight heparins (LMWH) were withdrawn due to the prevailing risk of bleeding.
After another two months, the patient was re-admitted to the Department. The laboratory parameters were normal again, and the coagulation tests did not change significantly (PT 13.7s, APTT 30.0s, INR 1.04). Follow-up MRI scans were performed. MRI showed a reduction in the size of the hematoma to 33 x 16 x 22 mm [Fig. 2], while ultrasound showed the left femoral nerve with a preserved continuity, normal echostructure, non- thickening, and no signs of focal neuropathy.
On neurological examination, the patient showed slight improvement (2 in the Lovette scale), but the symptoms of femoral nerve paresis were still present.
After the hospitalization, the patient was ordered regular (3 times a week) physiotherapy. After rehabilitation, the symptoms of femoral nerve palsy decreased significantly. The active flexion movement in the hip joint (slightly weakened) and extension in the knee joint returned (4 in the Lovette scale).
The area of cutaneous hypoaesthesia on the inside of the thigh and lower leg also decreased. This improvement allowed the patient to replace the high walker (which she had been using until December 2021) for elbow crutches. The subjective quality of life improved significantly.
On April 7, 2022 a control MRI examination was performed [Fig. 3]. Compared to the previous study, the hematoma in the left hip muscle was absorbed, and in this localization there are no visible fibrosis and a strip of edema. Additionally, intensification of degenerative changes in the right hip joint was found.
At the last visit to the outpatient clinic in June 2022, the patient no longer reports problems with the left lower limb. The limb function has fully recovered, but she still has used crutches because of right hip. The patient was qualified to total hip replacement.