Conversion THR for failed hemiarthroplasty tied to good functional outcome and reliable pain relief

The most common indication for conversion total hip replacement (THR) is failed hemiarthroplasty. The various modes of failure are persistent hip pain, aseptic loosening, prosthetic joint infection, prosthetic stem breakage, dislocation, periprosthetic fracture and limb length discrepancy.

Natesan Rajkumar et al found in a study that - Conversion THR for failed hemiarthroplasty is a challenging procedure and results in good functional outcome and provides reliable pain relief.

The authors retrospectively analyzed 104 consecutive patients who underwent conversion THR for failed hemiarthroplasty. The patient’s records were analyzed for demographic information, index surgery details, preoperative functional status, and perioperative complications. Patients were analyzed according to the various modes of failure of hemiarthroplasty. The radiographs were analyzed for any progressive osteolysis, cup migration and stem subsidence. All the patients were evaluated using the modified Harris hip score (HHS) for clinical outcome. Complications, revision or reoperation in the follow-up period was recorded. Results

Key findings of the study were:

• A total of 73 patients were included in the study for final analysis after exclusion criteria.

• The average follow-up was 48.2 ± 29.6 months.

• There was a significant improvement in mean HHS from 38.5 ± 9.1 preoperatively to 80.9 ± 4.3 at the last follow-up ( p < 0.05).

• The different modes of failure had no statistically significant difference in the postoperative Harris hip score (p = 0.393).

• None of the patients had progressive radiolucent lines more than 2 mm or significant subsidence in the final follow-up compared to the initial postoperative radiograph.

• There was one deep infection, one patient had grade 2 heterotopic ossifi cation, intraoperative calcar fracture was fixed with cerclage wiring in 11 patients, and postoperative periprosthetic fracture in two patients was treated with plate osteosynthesis.

• There were no neurovascular complications or dislocation during the follow-up.

The authors concluded that – “Conversion THA for septic loosening by two stage revision have comparable postoperative outcomes like THA for aseptic loosening. Caution is required owing to high incidence of peri-prosthetic fracture during conversion THA. Dislocation rate is negligible even with smaller head provided the prosthesis is implanted in the proper orientation and adequate soft tissue balancing is achieved.”

Further reading:

Outcomes of Total Hip Replacement for Failed Hemiarthroplasty Natesan Rajkumar, Dhanasekaran Soundarrajan et al Indian Journal of Orthopaedics (2023) 57:679–688 https://doi.org/10.1007/s43465-023-00849-y