The Utility of a Plain Film Arthrogram to Confirm Acute Liner Dissociation in the Setting of Primary Total Hip Arthroplasty.

Acute Liner dissociation is a well-documented, but uncommon complication of total hip arthroplasty, yet the journey to diagnosis remains undefined. This clinical case report outlines the use of plain film arthrogram for diagnosis in a 53-year-old female who presented to the ED following a fall, describing symptoms of increasing groin pain, reduced range of movement, difficulty weight-bearing and a grinding sensation in her left hip, all on a background of total hip replacement two years ago. Examination revealed impaired flexion, rotation and abduction while AP pelvic X-ray confirmed mild eccentric placement of the femoral head, and lateral X-ray proved joint enlocation. An arthrogram of the left hip was performed the following day with injection of 4mls of iodinated contrast injected into the joint. Inferior dissociation of the liner from the shell was evident. The femoral head and liner were replaced two days later, and the liner was found to have shearing and gross plastic deformation at the rim. The patient reported immediate relief from the groin pain and was discharged on the fourth day postoperatively. This shows how plain film imaging fails in diagnosing acute liner dissociation dynamic fluoroscopic tests, post-arthrography CT and metal artifact reduction sequence magnetic resonance imaging (MARS MRI) have previously been proposed despite their associated wait-time, radiation exposure and financial costs. This case report highlights the role of plain film arthrography as a low risk and low-cost diagnostic tool. The report also suggests the incorporation of radio-dense markers in liners to facilitate the use of arthrography when diagnosing dissociation, also raising awareness of prevention and recognition in what may be an under-reported complication of hip arthroplasty.