This document discusses protrusio acetabuli, a hip joint deformity where the medial wall of the acetabulum invades into the pelvic cavity. It can be caused by primary or secondary factors like infections, tumors, inflammation, trauma or genetics. The first case was described in 1824. Diagnosis involves clinical exams and radiological imaging. Treatment depends on the patient's age and bone maturity, and may include surgical closure of growth plates in children, bone grafting in adolescents, or total hip arthroplasty in older adults. Placement of the hip prosthesis component is important to avoid loosening.

1. Dr.Ghazwan A. Hasan
5th year Arab Board Trainee

2. DEFINITION
• Is a hip joint deformity in which the medial wall of the
acetabulum invades into the pelvic cavity, with associated
medial displacement of the femoral head.
• It is caused by primary idiopathic and secondary neoplastic,
infectious, metabolic, inflammatory, traumatic, and genetic
disorders.
• 1st case was published by Adolph William Otto, a German
pathologist, in 1824
((the right acetabulum protrudes into the pelvis like half an
orange))
• In 1854, Gurlt blamed acetabular fractures as the cause of the
deformity, referring to it as ‘a coxalgia with acetabular fracture.

3. ETIOLOGY
 1ry
 2ndary
 Infectious (Gonococcus, Echinococcus, Staphylococcus, Streptococcus,
Mycobacterium tuberculosis).
 Neoplastic (Hemangioma, Metastatic carcinoma, Neurofibromatosis
Radiation-induced osteonecrosis.
 Inflammatory (Rheumatoid arthritis, Ankylosing spondylitis, Juvenile
rheumatoid arthritis, Psoriatic arthritis, Acute idiopathic chondrolysis,
Reiterís syndrome, Osteolysis, following hip replacement).
 Metabolic (Pagetís disease, Osteogenesis imperfecta, Acrodysostosis,
Osteomalacia Hyperparathyroidism )
 Traumatic (Sequelae of acetabular fracture Surgical error during hip
replacement)
 Genetic (Trichorhinophalangeal syndrome Stickler syndrome, Trisomy 18,
Ehler-Danlos syndrome, Marfan syndrome, Sickle cell disease).

4. DIAGNOSIS
 Clinical:
 Radiological:

5. CLASSIFICATION
• Sotelo-Garza and Charnley used the ilioischial line on an AP
radiograph of the pelvis as a reference point from which to
measure the location of the acetabulum.

6. TREATMENT
• Identification and treatment of any underlying disease process.
• Surgical Option is based on the patientís age and skeletal maturity and
the extent of degenerative changes visualized on plain radiographs.
• Skeletally Immature patients: Surgical Closure of Triradiate cartilage +/-
VITO.

7. TREATMENT
• Adolescent or Young Adult Patients: VITO by Pauwels

8. TREATMENT
• Older Adult Patients: VITO, THA
• Total hip arthroplasty is the recommended treatment for the
older adult with protrusio acetabuli and degenerative changes.
• Ranawat et al reported on 35 hips with protrusio acetabuli
secondary to rheumatoid arthritis that had been treated with
cemented THA and had been followed up for an average of 4.3
years. They reported loosening in 16 of 17 hips recon- structed
with the cup center more than 10 mm from the anatomic center.
Of the 13 hips reconstructed with the cup center within 5 mm of
the anatomic center, none was loose.
•

9. TREATMENT
• Bayley et al and Gates et al confirmed the importance of restoring the
hip to an anatomic center. They noted that 50% of reconstructed hips
with a cup center more than 10 mm from the anatomic hip center had
failed.
• Ranawat and Zahn have recommended the following guidelines: In
cases in which the protrusion is less than 5 mm, bone graft is not
required. When the protrusion is greater than 5 mm and there is an
intact medial wall, bone graft without augmentation devices is
appropriate.
• If there is gross deficiency of the medial wall, bone graft with
consideration of additional fixation devices (hemispherical non-
cemented cup with screw supplementation or antiprotrusio ring) is
indicated.

10. TREATMENT
• Ring Hip Prosthesis.

11. CEMENTLESS CUP TECHNIQUE
• McBride MT, Muldoon MP, Santore RF, Trousdale RT, Wenger DR. Protrusio acetabuli: diagnosis and treatment. J Am
Acad Orthop Surg. 2001; 9(2):79-88.
• Kroeber M, Ries MD, Suzuki Y, Renowitzky G, Ashford F, Lotz J. Impact biomechanics and pelvic deformation during
insertion of press-fit acetabular cups. J Arthroplasty. 2002; 17(3):349-354.

12. CASE PRESENTATION
• 52 years old female
• History of RTA presented with pelvic fracture 4 months
ago.
• Treated conservatively
• Presented with pain, Limitation of movement of Right
Hip.

16. POST OPERATIVE