NEW YORK — Infection eradication and limited stem migration occurred at 2-year minimum follow-up in patients who underwent staged total hip arthroplasty revision due to infection using a femoral impaction bone grafting technique. The results were similar to those seen with implantation of primary cemented taper-slip prostheses, according to a presenter at the Musculoskeletal Infection Society Annual Open Scientific Meeting.
Mukai Chimutengwende-Gordon, MB ChB, PhD, FRCS (Tr & Orth), a fellow in Trauma and Orthopaedics at Royal Adelaide Hospital in Adelaide, Australia, said she and her colleagues studied this technique to determine not only the extent of any stem subsidence or migration, but whether the 29 patients with infected THAs they treated would have improved Harris Hip Scores (HHS), Harris Pain Scores and Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT) activity scores over time, as well as infection eradication. Many of the patients also underwent an extended trochanteric osteotomy to explant an infected THA prosthesis.
Researchers isolated various microorganisms in the patients studied and about 25% of the cultures yielded mixed growth, Chimutengwende-Gordon said.
“In 27 out of 29 patients, there was no further recurrence of infection after the final stage with the femoral impaction bone grafting,” she said.
However, two patients had a recurrence of infection.
“Infection eradication was comparable to revision hip arthroplasty without impaction bone grafting. There were improvements in clinical outcomes at the 2-year minimum follow-up and in most cases, there was a similar migration pattern to that seen with primary cemented prostheses,” Chimutengwende-Gordon told Healio.com/Orthopedics.
Following a first stage to remove the infected stem, and placement of an interim prosthesis loaded with antibiotics, the impaction grafting technique was performed. It involved placement of cemented, polished double-taper stems that were 130 mm long in 19 patients.
This length of stem is typically shorter than those normally used in infection revision cases, according to Chimutengwende-Gordon, who noted two patients received stems that were 200 mm long or longer.
Tantalum beads placed during the final stage of the revision aided measuring femoral stem subsidence at 2 years postoperatively, which was 1.8 mm at the stem-bone interface and 0.05 mm at the cement bone interface, according to Chimutengwende-Gordon.
“We feel that the key to success in reducing subsidence is the surgical technique, including the bone graft preparation,” she said at the meeting.
Impaction grafting was performed with modular tamps and morselized, nonirradiated, femoral head allograft chips to which 250 mg of vancomycin was added.
“Mesh was used if there were any uncontained defects,” Chimutengwende-Gordon said, noting most of the patients had Paprosky grade 2 or 3 femoral defects.
Results showed the median HHS, Harris Pain and SICOT scores at 2 years all improved from baseline. – by Susan M. Rapp
Chimutengwende-Gordon M, et al. Femoral impaction grafting in staged revision for infected hip arthroplasty. Presented at: Musculoskeletal Infection Society Annual Open Scientific Meeting; Aug. 2-3, 2019; New York.
Disclosure: Chimutengwende-Gordon reports no relevant financial disclosures.