Utility of week one radiographs post total hip arthroplasty

Introduction: We retrospectively analysed 129 consecutive patients who underwent hip arthroplasty at a university-affiliated hospital in Melbourne, Australia between February and September 2011 with respect to the quality of the week one radiographs, placement of the prosthesis and the presence of a peri-prosthetic fracture or dislocation.

Method: Patient records and radiographs were reviewed to ascertain whether a deviation in routine management occurred based on the information obtained from week one post-operative radiographs.

Results: 116 of the 129 patients met the inclusion criteria for the study. 115 patients underwent routine week one hip radiographs with a mean time after surgery of 2.5 days. 89 (77%) of these patients had radiographs with a typical post-operative appearance. 26 (23%) had radiographs with an atypical appearance defined by the presence of one or more of the following: offset difference of >10 mm (11%), leg length difference of >10 mm (11%), sub-optimal acetabular component inclination of <30° or >50° (9%), sub-optimal femoral stem position of >5° varus or valgus (2%), sub-optimal femoral Greun cement distribution of 2 or more absent zones (2%), cement extrusion (1%), peri-prosthetic fracture (0) or dislocation (0). None of the routine week one radiographs resulted in a change in early post-operative management. 1 patient underwent non-routine, immediate post-operative radiographs.

Discussion: Our study did not demonstrate a case where deviation from standard clinical pathways occurred as a result of routine post-operative radiographs. A higher power study would help the established surgeon to determine whether post-operative radiographs could be performed at a more comfortable and convenient time such as the outpatient setting.