arthroplasty
Complex Primary THA - Childhood Hip Disorders
advanced
6 min
20 marks
5 questions
Clinical Scenario
A 70-year-old patient presents with severe left hip pain failing non-operative management. They recall "hip trouble" as a child with prolonged hospitalization and a draining wound. On examination, there is a healed sinus scar behind the hip, the leg is shortened by 4cm, and fixed flexion deformity of 20°. Hip ROM is severely restricted.
AP pelvis radiograph showing left hip with features of previous childhood hip pathology. Shallow dysplastic acetabulum, proximally migrated femoral head, shortened femoral neck, and soft tissue calcification suggesting previous infection.
Image source: Open Access medical literature (NIH/PubMed Central) • CC-BY License
Questions
Question 1 (3 marks)
What was the likely childhood diagnosis and what anatomical abnormalities would you expect?
Question 2 (5 marks)
What specific points would you address when consenting this patient for THA?
Question 3 (4 marks)
What preoperative investigations would you perform?
Question 4 (5 marks)
Describe the key operative principles and steps for this case.
Question 5 (3 marks)
What postoperative management considerations are specific to this case?
Exam Day Cheat Sheet
Must Mention
- •Dormant infection risk from childhood - may reactivate
- •Leg length: unlikely to equalize fully; nerve palsy risk if >4cm lengthening
- •Find TRUE acetabulum: TAL remnant, teardrop landmark
- •Subtrochanteric shortening osteotomy if cannot reduce
- •Extensive scar tissue: protect sciatic nerve, vessels
- •CT essential for planning
Common Pitfalls
- •Promising leg length equalization
- •Not investigating for dormant infection
- •Inadequate exposure (mini-incision)
- •Excessive lengthening
- •Not protecting sciatic nerve
- •Missing true acetabulum