Femoral artery dissection or pseudoaneurysm: Although the question mentions no hematoma and strong pulses, a dissection or pseudoaneurysm could still occur without significant external signs, especially early on. Sharp groin pain is a common presentation.

Femoral artery thrombosis: Despite strong pulses, thrombosis could be partial or the pain could be due to a small, non-occlusive thrombus. The absence of a hematoma does not rule out thrombosis.
Access site complication (e.g., arteriovenous fistula): Although less common, an arteriovenous fistula could cause pain and might not immediately present with a significant hematoma.
Nerve injury: The femoral nerve runs close to the femoral artery, and procedures in this area can sometimes cause nerve irritation or injury, leading to sharp pain.

Retroperitoneal hemorrhage: This is a potentially life-threatening condition that might not always present with an obvious hematoma, especially if the bleeding is contained within the retroperitoneal space. Strong pulses do not rule out this condition.
Aortic dissection (if the procedure involved the aorta): Although the primary procedure was femoral angioplasty, any manipulation of the aorta or its major branches could potentially lead to dissection, which is a medical emergency.

Femoral artery perforation: This would be an unusual complication without significant hematoma formation but could potentially cause sharp pain if the perforation is small or contained.
Infection: Early infection after angioplasty is rare but could present with pain. However, this would typically be accompanied by other signs of infection such as fever or redness.
Vasospasm: This could potentially cause sharp pain but is less common and might be associated with other symptoms such as decreased pulses or coldness in the affected limb.