Meralgia Paresthetica: This condition is characterized by numbness, tingling, and burning pain in the outer part of the thigh. However, it can sometimes present with sharp pain, especially if the lateral femoral cutaneous nerve is compressed or irritated, which is more common in older adults due to weight gain, tight clothing, or other factors that increase pressure on the nerve.

Groin Strain: A common injury in older men, especially those who engage in physical activities, causing sharp pain in the upper inner thigh due to muscle strain.
Osteoarthritis of the Hip: Can cause referred pain to the upper inner thigh, especially if the joint cartilage is worn down, leading to bone-on-bone contact and inflammation.
Tendinitis: Inflammation of the tendons around the hip or thigh can cause sharp pain, especially with movement.

Femoral Hernia: Although less common than inguinal hernias, femoral hernias can cause severe, sharp pain in the upper inner thigh and can lead to bowel obstruction or strangulation if not promptly treated.
Aortic Aneurysm or Aortic Dissection: These are life-threatening conditions that can cause severe, sharp pain that may radiate to the thigh, among other symptoms.
Deep Vein Thrombosis (DVT): Can cause pain, swelling, and warmth in the thigh, and it's crucial to diagnose and treat promptly to prevent pulmonary embolism.

Avulsion Fracture: A rare condition where a fragment of bone tears away from the main mass of bone as a result of physical trauma, which could cause sharp pain if it occurs in the upper inner thigh area.
Neurogenic Tumors: Rare tumors that arise from nerve tissue, such as schwannomas or neurofibromas, which can compress nerves and cause sharp pain in the distribution area of the affected nerve.
Paget's Disease of Bone: A chronic condition that can result in enlarged and misshapen bones due to abnormal bone destruction and regrowth, potentially causing pain in the affected areas, including the thigh.