This study was be performed on 60 patients with ulnar neuropathy at elbow diagnosed clinically and by electrophysiology and/or ultrasonography selected from Physical medicine, Rheumatology & Rehabilitation Department, Faculty of Medicine, Tanta University.

Patients were be randomly divided into 2 groups:

Group I: will undergo a single ultrasound-guided deep perineural injection with 3ml PRP at the thickest part of the ulnar nerve. PRP will be prepared by PRP method.

Group II: will undergo a single ultrasound-guided deep perineural injection with 1ml corticosteroid (triamcinolone acetonide, 40mg/mL) mixed with 1ml lidocaine hydrochloride.

Inclusion Criteria:

• Patients with ulnar neuropathy at elbow diagnosed clinically and by electrophysiology and/or ultrasonography.

Exclusion Criteria:

1. Patients with severe ulnar neuropathy at elbow according to Gu's classification. 15

2. Brachial plexopathy, peripheral neuropathy, and cervical radiculopathy.

3. History of recent elbow trauma or operation.

4. Malignant neoplasm.

5. Pregnancy.

6. Bleeding Disorders.

7. Factors affecting nerve healing process e.g., tobacco use and systemic corticosteroid administration.

8. Contraindications for PRP injection:

   1. Significant renal or hepatic dysfunction.
   2. Critical thrombocytopenia.
   3. Hemodynamic instability.
   4. Septicemia.
   5. Local infection at the site of the procedure.
   6. Consistent use of nonsteroidal anti-inflammatory drugs within the last two weeks.
   7. Local injection at the suspected treatment site within the last month.
   8. Recent fever or illness.
   9. Hemoglobin level <10 g/dL.
   10. Platelet dysfunction disorders.