Aim

Diagnosis of periprosthetic shoulder infections (PSI) is difficult as they are mostly caused by low-virulent bacteria and patients do not show typical infection signs, such as elevated blood markers, wound leakage, or red and swollen skin. Ultrasound-guided biopsies for culture may therefore be an alternative for mini-open biopsies as less costly and invasive method. The aim of this study was to determine the diagnostic value and reliability of ultrasound-guided biopsies for cultures alone and in combination polymerase chain reaction (PCR), and/or synovial markers for preoperative diagnosis of PSI in patients undergoing revision shoulder surgery.

Background

Both from experimental studies and the large arthroplasty registries there is evidence that bacteria are more often involved in implant loosening then is currently reported. To further elucidate this potential problem, the current study investigated the hypothesis that many total hip arthroplasty revisions, classified as aseptic, are in fact low-grade infections missed with routine diagnostics.

Background

Because of the long life expectancy of young total hip arthroplasty (THA) patients and the limited durability of prosthetic implants in young patients, surgeon's always must take into account that the primary THA will be revised in the future. Therefore, not only the survival of the primary total hip in young patients is important, but we would also like to accentuate the revisability of a primary THA in this specific and high demanding patient population.

Introduction: Loosening of acetabular components often lead to excessive bone defects. Managing severe acetabular bone loss in revision arthroplasty is a serious or sometimes even an impossible challenge. Several authors even have published disappointing results. The purpose of this study was to evaluate the long term clinical and radiographic results of acetabular reconstruction with the use of bone impaction grafting and a cemented cup in cases with very large acetabular defects.

Methods: In this historical prospective study, 27 hips (25 patients) with large acetabular defects (AAOS type III and IV, Paprosky type 2B to 3B) were reviewed. In all cases an extensive reconstruction with the use of bone impaction grafting and a large rim wire mesh (Stryker Howmedica, Newbury, UK) was performed. All patients have had a six week bed rest period or 3 weeks of bed rest with 3 weeks of non-weight bearing mobilization. No patient was lost to follow-up. Three patients died during follow-up, the cause of death was in all cases not related to the surgery. All medical files and radiographs were analyzed.

Results: After a mean follow-up of 8.8 years (range 4 to 14.1), 3 hips needed repeat revision and another 2 hips were considered radiographic loose. Reasons for repeat revision were: septic loosening after 4.7 years, aseptic/traumatic loosening after 5.8 years and a broken-out reconstruction after 5 weeks because lack of compliance of the patient.

Kaplan-Meier analysis showed a ten-year survival rate of 87% (95%C.I. 73.1–100%) with end point acetabular revision for any reason and 95% (95%C.I. 86.2–100%) with end point acetabular revision because of aseptic loosening. The mean preoperative HHS was 55 points and improved to 72 points postoperative.

Conclusion: Acetabular reconstruction using impaction bone grafting and a cemented cup can produce favorable long-term results in patients with massive acetabular bone-stock defects. It is the only revision technique which restores massive acetabular bone stock loss. However, in these extensive defects it is a technical demanding procedure and should only be used by surgeons with extensive experience with this technique.

Introduction : The reason why heterotopic ossification develops after total hip arthroplasty is still not known, but it is assumed that inflammatory reaction is the major driving force. In literature little is known about the cytokine levels at the site of surgery, most measurements are done in serum. This study was conducted to investigate if the levels of different pro- en anti-inflammatory cytokines are measurable in drainage fluid and, when measurable, whether we can find a difference in cytokine concentration between one and six hours postoperatively.

Materials and methods: Samples from the drainage system in 30 consecutive patients undergoing primairy total hip replacement were collected at one and six hours after closure of the wound. GM-CSF, G-CSF, IFN-γ, TNF, MCP-1, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13 and MIP-1beta levels were measured in the drainage fluids.

Results: Measurable levels of all cytokines studied were found, except for IL-17. A significant elevation of almost all cytokines was observed between the sample after one hour and six hours postoperatively. The elevation was significant for all cytokines except IL-10 and MIP-1b. We found a strong correlation between the different pro-inflammatory cytokines. Levels are much higher than previously shown levels in serum. When computing the IL-6 to IL-10 ratio, this ratio increased from 304 (SD 256) to 12357 (SD 6788) (p< 0,000), which shows an increased predominance of the pro-inflammatory interleukines when comparing the measurements after one and six hours respectively.

Conclusion: Detectable levels of numerous cytokines can be measured in drainage fluid post-operatively. The levels of most cytokines in drainage fluid are higher in samples taken six hours after surgery as compared to samples taken after one hour. Further studies are needed to detect the relation between these cytokine concentrations and the heterotopic bone formation.