Differential Diagnosis for Left Hip Pain after Picking up a Watermelon

Single Most Likely Diagnosis

• Muscle Strain: This is the most likely diagnosis given the context of lifting a heavy object like a watermelon. The sudden exertion can lead to strain in the muscles around the hip, particularly the hip flexors or gluteal muscles.

Other Likely Diagnoses

• Ligament Sprain: Similar to muscle strain, the ligaments around the hip joint can be sprained during heavy lifting, leading to pain and instability.
• Tendinitis: The tendons of the hip, such as the iliotibial (IT) band or the gluteus medius tendon, can become inflamed due to overuse or direct injury from lifting, causing hip pain.
• Bursitis: The bursae around the hip joint can become inflamed (bursitis) due to direct trauma or repetitive friction from activities like lifting, leading to hip pain.

Do Not Miss Diagnoses

• Hip Fracture: Although less likely, a hip fracture (e.g., femoral neck fracture) is a critical diagnosis not to miss, especially in older adults or those with osteoporosis. The mechanism of injury (lifting a heavy object) could potentially lead to a fracture.
• Avulsion Fracture: An avulsion fracture, where a fragment of bone is pulled off by a tendon or ligament, is another serious condition that could occur from the sudden force of lifting a heavy object.
• Septic Arthritis: Although rare, septic arthritis of the hip is a medical emergency that requires prompt diagnosis and treatment. It could present with acute hip pain and might not be directly related to the lifting incident but should always be considered.

Rare Diagnoses

• Stress Fracture: A stress fracture in the hip or pelvis could occur from repetitive stress rather than a single incident of lifting. However, it's less likely to be directly caused by picking up a watermelon.
• Osteonecrosis: Osteonecrosis of the femoral head could present with hip pain but is less directly related to the act of lifting a heavy object and more related to underlying conditions or chronic steroid use.
• Piriformis Syndrome: This condition, where the piriformis muscle irritates the sciatic nerve, could cause hip and buttock pain but is less likely to be directly caused by the described incident.