INTRA-PELVIC MIGRATION OF FEMORAL HEAD TRIAL IN TOTAL HIP ARTHROPLASTY, A RARE INTRAOPERATIVE COMPLICATION. OUR EXPERIENCE AND SYSTEMATIC REVIEW OF LITERATURE

Introduction

Trial reduction while performing total hip replacement is an essential step of the procedure. This is to check the stability of the hip joint with the selected implant sizes and to assess the leg length to avoid discrepancy.

Disengagement of the femoral head trial from the femoral rasp stem, with subsequent migration of the trial head into the pelvic cavity is a rare occurrence, but can be a very frustrating complication to both the surgeon and occasionally the patient.

We present our experience with this exceptional situation and different management options, together with systematic review of the literature.

Patients and methods

We conducted Medline database search via Pubmed interface. MeSH search was used. Systematic review of English literature case reports was performed.

15 reports were found discussing intra-pelvic migration of different arthroplsty related materials.

The total number of reported cases was 24 cases, out of those, 21 cases were related to migration of femoral trial head, 2 cases of migrated modular hemiarthroplasty bipolar heads and one case of migrated femoral head definitive implant.

Results and discussion

Migration of femoral head trial or prosthesis into the pelvic cavity is likely to be an under-reported incidence considering the number of cases found in literature.

In the reported cases, when dislocating or reducing the femoral head trial, it disengaged from the rasp trial stem or the definitive femoral stem. Usually the surgeon tries to retrieve the trial head by finger exploration, however it usually ends up being pushed further intra-pelvic. Similar pattern was described in the reports of migrated definitive prosthetic head and bipolar hemiarthroplasty modular heads.

Conclusion

The dissociation of the femoral head during a THR is a rare complication. It is proved to be difficult to retrieve the head once disengaged.

Co-ordination with assistant is important. Seeking senior surgeon assistance during the procedure is a reasonable approach. Closure and preparing for a second planned procedure to extract the head seems to be a safe option after proper imaging to localize the trial head. Keeping the patient informed about the unfortunate intra-operative event is a must.