Is Preoperative Identification of the Infecting Organism Essential Before Single-Stage Revision Hip Arthroplasty for Periprosthetic Infection?

BACKGROUND: It is commonly stated that identification of the infecting organism is a prerequisite to single-stage revision arthroplasty of the hip for deep infection. We have performed single-stage revision in a series of patients where the organism was not identified preoperatively. The aim of this study is to investigate whether the rate of infection eradication following single-stage revision was affected by preoperative knowledge of the infecting organism. METHODS: We identified all patients who had undergone a single-stage revision for a deep infection at our hospital between 2006 and 2015. One hundred five patients were assigned into 2 groups based upon whether the infecting organism had been identified preoperatively (group A = 28) or not (group B = 77). RESULTS: The reinfection rates were 3.6% in group A and 9.1% for group B (P = .679). Re-revision rates were 7.1% and 9.1%, respectively (P = 1.00). Overall, the implant survival rate at 6 years was 87.9% (95% confidence interval, 97.4-78.4). In group B, preoperative aspiration was performed in 36.4% (28/77) of cases. Staphylococci species were the predominant causative organisms, with gram-negative involvement in 19.0% (20/105) of cases. CONCLUSION: The rate of infection eradication and overall survivorship with single-stage revision was similar in our series to that reported in the literature. While desirable, we did not find identification of the infecting organism before surgery influenced the outcome. Given the functional and economic benefits of single-stage revision, we suggest that failure to identify an organism is not an absolute contraindication to this approach.

Fractured Femoral Stems in Primary and Revision Hip Arthroplasties Revisited: Wrightington Experience.

BACKGROUND: The aim of this study is to present our experience in managing fractured femoral stems over the last 10 years for both primary and revision stems at our tertiary unit focusing on modes of failure and operative techniques. METHODS: This is a retrospective consecutive study of all patients with fractured femoral stems that were operatively managed in our unit between 2008 and 2018. Detailed radiographic evaluation (Paprosky classification) was undertaken and data collected on operative techniques used to extract distal fractured stem fragments. RESULTS: Thirty-five patients (35 hips) were included (25 men/10 women) with average age at time of presentation of 68 years (range, 29-93). Average body mass index was 30 (standard deviation, 3.8; range, 22.5-39). There were variety of stems both contemporary and historical, primary and revision cases (15 hips polished tapered cemented stems, 10 hips composite beam and miscellaneous stems, and 10 revision hip stems). The predominant mechanism of failure was fatigue due to cantilever bending in distally fixed stems. Surgical techniques used to extract distal fragment were drilling technique in 2 hips, cortical window in 13 hips, extended trochanteric osteotomy (ETO) in 5 hips, and proximal extraction in 15 hips. CONCLUSION: When faced with a contemporary fractured stem, drilling techniques into the distal fragment are unlikely to succeed. If a trochanteric osteotomy had been used at time of index surgery, this could be used again to aid proximal extraction with conventional revision instrumentations. The cortical window technique is useful but surgically demanding technique that is most successful in extracting polished tapered fractured stems particularly when an ETO is not planned for femoral reconstruction. Use of trephines can be useful for removal of longer, uncemented stems. Finally, an ETO might be necessary when other techniques have failed.

Acetabular revision with bone grafting and cementation for aseptic loosening after primary Charnley low-friction hip arthroplasty with structural bulk autografts.

PURPOSE: To review the outcome of acetabular revision with bone grafting and cementation for aseptic loosening after primary Charnley low-friction hip arthroplasty with structural bulk autografts in 15 patients. METHODS: Records were reviewed for 3 men and 12 women aged 31 to 72 (mean, 53) years who underwent acetabular revision with bone grafting and cementation for aseptic loosening at a mean of 12.4 (range, 6.6-20.3) years after primary Charnley low-friction hip arthroplasty with superolateral structural bulk autografts from the femoral head for dysplastic hip (n=14) or bone loss secondary to acetabular fracture (n=1). RESULTS: After a mean follow-up of 6.7 (range, 1.1-14.5) years, the mean Merle d'Aubigné and Postel score improved from 8.55 to 16.5. Bridging trabeculae was noted in 10 hips and graft remodelling in 5 hips. Five hips had ectopic ossification of Brooker grade 1 to 2. The mean hip centre of rotation was 21.6 (range, 16.2-30.6) mm. Two women required re-revision for aseptic loosening of the acetabulum after 8.5 and 6.6 years. The first one underwent re-revision with solid allograft for superolateral deficiency of the acetabulum. The second one underwent re-revision with solid and morselised bone allografts for loosened acetabulum. One patient had superior migrationof the acetabulum for 9 mm at year 2, but it was asymptomatic. One patient had a dislocation that was reduced with manipulation under anaesthesia. Threepatients had trochanteric non-union and presented with lateral thigh pain and tenderness, but no further surgery was performed. CONCLUSION: The medium-term outcome of acetabular revision with bone grafting and cementation is satisfactory. Repeat bone grafting is required to restore the anatomic acetabular position and bone loss secondary to acetabular loosening.

The C-stem in clinical practice: fifteen-year follow-up of a triple tapered polished cemented stem.

The triple tapered polished cemented stem, C-Stem, introduced in 1993 was based on the original Charnley concept of the "flat back" polished stem. We present our continuing experience with the C-Stem in 621 consecutive primary arthroplasties implanted into 575 patients between 1993 and 1997. Four hundred and eighteen arthroplasties had a clinical and radiological follow-up past 10 years with a mean follow-up of 13 years (10-15). There were no revisions for stem loosening but 2 stems were revised for fracture - both with a defective cement mantle proximally. The stem design and the surgical technique support the original Charnley concept of limited stem subsidence within the cement mantle and the encouraging results continue to stand as a credit to Sir John Charnley's original philosophy.

A technique for extracting a buried Kuntscher nail from the femur during total hip arthroplasty.

We describe a novel technique that allows safe extraction of a buried Kuntscher nail during total hip arthroplasty in a patient with ipsilateral, symptomatic post-traumatic osteoarthritis of the hip. This method allows the surgeon to visualise the antegrade entry point of the nail allowing safe extraction of the device without compromising the result of the hip arthroplasty.

Surface-active phospholipid in total hip arthroplasty.

This is the first report of surface-active phospholipid as the boundary lubricant in total hip arthroplasty. Aspirate and rinsings from the bearing surfaces of 25 revision operations and one primary surgery were analyzed from 3 weeks to 26 years postoperatively. All samples contained substantial amounts of surface-active phospholipids ranging from 14 to 4186 microg. These findings indicate that synoviocytes continue producing the lubricant in significant quantities after arthroplasty surgery independent of the type of joint replacement and its fixation. Surface-active phospholipid was found on all bearing surfaces analyzed including polyethylene, stainless steel, chrome cobalt, alumina, zirconia, and titanium.