• Deep-vein thrombosis (DVT), a blood clot in the leg. Hip fracture surgery, older age, and reduced movement raise the risk. It can cause one-sided leg swelling and pain, and the risk remains for around 3 months after surgery. A clot can travel to the lungs. AAOS DVT guidance notes this risk after lower-limb surgery.
• Infection around the hip prosthesis, especially if there is fever, wound discharge, redness, warmth, or worsening pain.
• Periprosthetic fracture, meaning a fracture around the implant, or other implant-related problem. Pain, thigh/hip swelling, and inability to bear weight are warning features. AAOS information lists these symptoms.
• Less urgent possibilities include postoperative swelling, stiffness, weak muscles, or soft-tissue inflammation, but these should only be considered after the dangerous causes are excluded.

Go to emergency immediately / call local emergency services if she has

• Shortness of breath, chest pain, coughing blood, fainting, or sudden fast heartbeat
• A rapidly more swollen, red, hot, or painful calf/thigh
• Fever, chills, confusion, wound pus/drainage, or opening of the wound
• A suddenly shortened or rotated leg, a fall, or new inability to move the leg

What the hospital/orthopaedic team should assess

• Examination of hip, wound, leg circulation, and nerves
• Repeat hip and full-femur X-rays in proper views, compared with earlier films
• Urgent venous Doppler ultrasound of the swollen leg to check for DVT
• Blood tests: CBC, CRP, ESR, kidney function, and infection evaluation as indicated
• If infection or implant complication is suspected, the surgeon may order further imaging and possibly joint aspiration before antibiotics, when clinically safe.

Until she is assessed

• Do not force walking, weight-bearing, or painful physiotherapy.
• Do not massage the swollen leg.
• Keep her from falling. Use a walker/wheelchair and assistance for transfers.
• Elevate the leg gently when resting, unless she develops breathing/chest symptoms.
• Bring operative records, discharge papers, medication list, and all previous X-rays. Mention whether she received blood-thinner injections/tablets after surgery and when they stopped.

1. Repeat X-rays of the left hip and entire femur
   • AP pelvis plus lateral hip views
   • Full-length femur views if possible
   • Compare with the immediate postoperative X-rays
     This checks for a fracture around the implant, implant movement/loosening, dislocation, or other bone problem. Standard assessment of suspected periprosthetic fracture includes AP and lateral views and imaging of the bone above and below the joint. Rockwood and Green's Fractures in Adults, 10th ed.
2. Urgent duplex Doppler ultrasound of the whole left leg veins
   • To rule out DVT, given unilateral swelling, pain, poor mobility, age, and hip surgery.
   • Do not rely on a D-dimer blood test alone in this setting. The ultrasound is the priority.
3. Blood tests
   • CBC with differential
   • CRP and ESR for inflammation or infection around the prosthesis
   • Kidney function/electrolytes: creatinine, urea, sodium, potassium
   • Blood glucose, particularly if diabetes is possible
   • Consider liver function and coagulation tests if anticoagulation or surgery may be needed.
4. If infection is suspected from symptoms or raised CRP/ESR: hip-joint aspiration
   • Usually image-guided by an experienced surgeon/radiologist.
   • Send fluid for cell count and differential, Gram stain, aerobic and anaerobic cultures, and local periprosthetic-infection tests where available.
   • Ideally obtain cultures before starting new antibiotics, unless she is systemically unwell or septic. ESR and CRP are standard initial screening tests, with aspiration used for further diagnosis when infection remains a concern, as described by AAOS.
5. CT scan of hip/femur only if X-rays are unclear or show a suspected complication
   • Helpful to define an occult fracture, implant position, bone loss, or collection.
   • It is not the first test if plain X-rays and Doppler have not yet been done.

If she has chest pain, breathlessness, fainting, low oxygen, or rapid heartbeat