Radiology Rounds #17

Clinical History

The patient is a 75 y.o. man with a history of end-stage left hip osteoarthritis who underwent total hip arthroplasty 7 years prior to his visit who returns today for follow-up. His overall health has been quite good, but he describes some mild recent-onset discomfort in the left groin region that is slightly worse with weight-bearing and is relieved with rest. He denies any fevers, chills, night sweats, skin rashes, or other systemic symptoms. On examination, he has mild limitation of motion on external rotation of the left hip, but no evidence of peripheral synovitis or bursitis. Hip radiographs are promptly obtained and are compared to his baseline films from several years ago

Radiographic Films

Film 1
Film 1

Film 2
Film 2

Radiographic Findings

A radiograph of the pelvis (film 2) demonstrates marked wear of the acetabular liner, with superolateral displacement of the femoral head (red arrow). There is a large radiolucent area superior to the left acetabular component (yellow arrow), and bony resorption of the proximal medial femur adjacent to the insertion site of the femoral prosthetic component (green arrow). These changes are not seen on his previous film (film 1).

Film 1a
Film 1

Film 2a
Film 2

Diagnosis and Discussion

Correct Diagnosis: Periprosthetic Osteolysis following total hip arthroplasty

Discussion:
Periprosthetic osteolysis, also known as cement or particle disease, is one of the feared long-term complications of total hip arthroplasty. First described in 1975, it was initially believed to be caused by the cement used to hold the components in place. It is now believed to result from an inflammatory response to the high-density polyethylene, polymethylmethacrylate (PMMA), titanium, or other alloy particles used to manufacture the prosthetic devices themselves. Indeed, surgical specimens reveal particle-laden macrophages in areas of bone resorption in all cases. Because the disease is caused by particulate matter, the osteolysis can occur anywhere along the bone:component interface, including areas such as empty screw holes in the acetabular component. There is little evidence to suggest that co-morbid illnesses, medication use, or specific surgical factors predispose to the development of this condition.

Patients may remain asymptomatic or describe only modest pain on weightbearing during the osteolytic phase of the disease. Most surgeons therefore obtain films at 2 years on all patients in order not to miss this asymptomatic phase of the process. As the osteolysis becomes increasingly severe, aseptic loosening may occur, with failure of the femoral and/or acetabular components. When this occurs, spontaneous periprosthetic fracture due to migration of the components, limb shortening, and severe pain are usually seen. Although several medical therapies have been described, including the use of bisphosphonates, NSAIDs, pentoxifylline, and even TNF inhibitors, surgical revision is almost always necessary to correct the defects.

References

  1. Wang ML, Sharkey PF, Tuan RS Particle bioreactivity and wear-mediated osteolysis. Arthroplasty 19(8):1028-38, 2004.
  2. Saleh KJ, Thongtrangan I, Schwarz EM. Osteolysis: medical and surgical approaches. Clin Orthop (427):138-47, 2004.
  3. Jones LC, Hungerford DS. Cement disease. Clin Orthop (225):192-206, 1987.
  4. Schmalzried TP, Jasty M, Harris WH. Periprosthetic bone loss in total hip arthroplasty. Polyethylene wear debris and the concept of the effective joint space. J Bone Joint Surg Am 74(6):849-63, 1992.

Updated: July 9, 2012

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