Debridement, antibiotics and implant retention in early periprosthetic joint infection.

INTRODUCTION: Periprosthetic joint infection (PJI) is a devastating complication in hip arthroplasty surgery. Debridement, antibiotics (AB) and implant retention (DAIR) is recommended in early PJI in association with stable implants. The aim of this study was to evaluate the success rate of DAIR in early PJI (<4 weeks) and to identify factors predicting the outcome. METHODS: This cohort study included a consecutive series of 35 patients (median age 74 years, 25 women, 26 primary arthroplasties) treated with DAIR for an early PJI in a regional hospital. RESULTS: 28 patients (80%) had their infection eradicated. DAIR-only eradicated the PJI in 22 (63%) patients with a median follow-up of 50 (24-84) months. In 17 (49%) patients, oral AB had been given prior to intraoperative cultures, which delayed first debridement with average 6 days and delayed hospital stay. Primary surgery for a hip fracture increased the risk of DAIR-failure. Surgical experience did not affect the outcome. 17% (n = 6) of the patients sustained a secondary infection during their hospital stay; the majority was beta-lactam resistant coagulase negative Staphylococcus aureus. CONCLUSIONS: The success rate of DAIR was inferior to pervious controls from experienced revision centers. Hip fracture patients should be informed about the increased risk of DAIR treatment failure. In order not to delay surgery, empirically based oral AB should not be administered prior to deep cultures. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02087020.

Ureaplasma urealyticum infection in total hip arthroplasty leading to revision.

We describe an infection with Ureaplasma urealyticum causing rapid loosening of a cemented total hip arthroplasty. When reviewing the literature we found that no such case has been reported previously. Taking intraoperative cultures for U urealyticum during revision surgery is not a standard procedure. In cases with rapid, presumed aseptic, loosening of a total hip arthroplasty, an infection with U urealyticum should be considered.

Good results with an uncemented proximally HA-coated stem in hip revision surgery: 62 hips followed for 2-13 years.

BACKGROUND AND PURPOSE: Proximal bone loss due to stress-shielding is a matter of concern after uncemented femoral hip revision. We have used short, proximally hydroxyapatite-coated prostheses in revision since 1989, and we now report the results. METHODS: 60 patients (62 hips) were revised because of aseptic loosening. Bone defects prior to revision were mostly of type II according to the Gustilo-Pasternak and Endo-Klinik classifications. Follow-up time was 73 (24-161) months. 9 patients had died before follow-up; 8 of these still had the stem in place. Clinical assessment was performed with the Harris hip score. Radiographs were evaluated for bone defects at revision, postoperative stem fixation, and periprosthetic bone remodeling. RESULTS: Mean Harris hip score was 75 (30-100) points. There was no stem loosening or progressive subsidence. 8 patients had mild to moderate thigh pain. Osteolysis, present at revision, had diminished, partially or completely, in four-fifths of the hips at follow-up. 4 hips had required re-revision due to fracture or dislocation. The 6-year prosthesis survival rate was 95% (95% CI: 0.83-0.98). INTERPRETATION: Uncemented revision with a short, proximally hydroxyapatite-coated prosthesis is a reliable procedure with encouraging results in the medium term if bone defects at revision are moderate.

Periprosthetic proximal bone loss after uncemented hip arthroplasty is related to stem size: DXA measurements in 138 patients followed for 2-7 years.

BACKGROUND: Periprosthetic bone loss occurs around uncemented femoral stems and may be influenced by the stem size. PATIENTS AND METHODS: We studied 138 consecutive patients, 3 (2-7) years on average after a total hip arthroplasty operation (THA) for unilateral osteoarthritis with the Bi-Metric uncemented femoral stem. We analyzed Harris hip score and bone mineral density. RESULTS: The mean Harris hip score was 97 at follow-up. Bone mineral density decreased proximally by 19% in both Gruen zones 1 and 7. Bone loss in zones 1, 2, 6, and 7 was significantly associated with stem size. Distally, a small gain in bone mass was found in zones 3 and 5 for medium femoral sizes. INTERPRETATION: We found a marked proximal BMD loss, especially for the larger stems, which may be specific for this particular implant. Long-term studies should reveal whether this proximal bone loss will affect the longevity of the THA.