Aims

There is increasing evidence to support the use of topical antibiotics to prevent surgical site infections. Although previous research suggests a minimal nephrotoxic risk with a single dose of vancomycin powder, fracture patients often require multiple procedures and receive additional doses of topical antibiotics. We aimed to determine if cumulative doses of intrawound vancomycin or tobramycin powder for infection prophylaxis increased the risk of drug-induced acute kidney injury (AKI) among fracture patients.

Introduction. Surgical site infections (SSI) are related to a surgical procedure and affect the surgical wound or deeper tissues. With continuing emphasis on clinical governance and quality control, there is increasing demand from both patients and government for methods of assessing surgical results. Rates of morbidity and mortality may play important roles in these assessments. When crude comparisons between hospitals in the incidence of SSI are made, these should at least be stratified by the type of procedure. The aim of this study is to fix SSI incidence in relation to surgical procedure. Methods. This report contains data of 19.948 procedures collected from 1996 to 2008 at a Specialist Orthopaedic Hospital and analyzed by a specific software designed for the study of infection in orthopaedic and trauma surgery. The SSI surveillance is focused on categories of surgical procedure (Hip Arthroplasty, Knee Arthroplasty, Spine Surgery and Hip Fracture Surgery) with each category containing a defined set of similar procedures. A basic of demographic data and details about operation itself are collected for each procedure. Patients are followed up throughout their hospital stay and after hospital discharge. We present the incidence of SSI by risk group and surgical procedure. SSI are categorized in type, moment of diagnosis and micro-organisms reported. Analysis of the data was performed (SPSSv15.0 ®). Statistical methods used to determine significance were the independent samples t test, Pearson X2 test, Odds ratio and Spearman correlation coefficient, with a significance level of p<0,05. Results. Rates of SSI are highest in hip hemiarthroplasty after fracture and in hip and knee revision procedures. Rates of SSI increase with the number of risk factors present in the patient, especially after fracture procedures. The most common infecting micro-organism was coagulase-negative staphylococcus, followed by Staphylococcus aureus, enterococci and streptococci. 38% of the infections arise after one year of surveillance. Conclusions. Our results confirm difference in rates of SSI depending of surgical procedure in orthopaedic and trauma surgery. We believe that our decision to monitor infection with a long term follow up it's the better way to avoid under-reporting of infection. Our study has also demonstrated the extent to which the emerging problem of infection due to MRSA has affected orthopaedic surgery. The risk of acquiring SSI caused by MRSA was particularly high in patients after hip fracture surgery. Rates of SSI increase with the number of risk factors present in the patient, especially after fracture procedures. Globally, the most common infecting micro-organism was coagulase-negative staphylococcus, followed by Staphylococcus aureus, enterococci and streptococci. 38% of the infections arise after one year of surveillance

Introduction. The degeneration of the adjacent segment in lumbar spine with spondylodesis is well known, though the exact incidence and the mechanism is not clear. Several implants with semi rigid or dynamic behavior are available to reduce the biomechanical loads and to prevent an adjacent segment disease (ASD). Randomized controlled trials are not published. We investigated the biomechanical influence of dynamic and semi rigid implants on the adjacent segment in cadaver lumbar spine with monosegmental fusion (MF). Materials and Methods. 14 fresh cadaver lumbar spines were prepared; capsules and ligaments were kept intact. Pure rotanional moments of ±7.5 Nm were applied with a Zwick 1456 universal testing machine without preload in lateral bending and flexion/extension. The intradiscal pressure (IDP) and the range of motion (ROM) were measured in the segments L2/3 and L3/4 in following situations: in the native spine, monosegmental fusion L4/5 (MF), MF with dynamic rod to L3/4 (Dynabolt), MF with interspinous implant L3/4 (Coflex), and semi rigid fusion with PEEK rod (CD Horizon Legacy) L3-L5. Results. Under flexion load all implants reduced the IDP of segment L2/L3, whereas the IDP in the segment L3/4 was increased using interspinous implants in comparison to the other groups. The IDP was reduced in extension in both segments for all semi rigid or dynamic implants. Compared under extension to the native spine the MF had no influence on the IDP of the adjacent disc. The rod instrumentation (Dynabolt, PEEK rod) lead to a decreased IDP in lateral bending tests. The ROM in L3 was reduced in all groups compared to the native spine. The dynamic and semi rigid stabilization in the segment L3/4 limited the ROM more than the MF. Discussion. The MF reduced the ROM in all directions, whereas the IDP of the adjacent segment remained unaffected. The support of the adjacent segment by semi rigid and dynamic implants decreased the IDP of both segments in extension mainly. This fact is an agreement with other studies. Compared to our data, no significant effect on the adjacent levels was observed. Interestingly, in our study, the IDP of the adjacent segment is unaffected by MF. The biomechanical influence in the view of an ASD could be comprehended, but is not completely clear. The fact of persistent IDP in the adjacent segment suggests that MF has a lower effect on the adjacent segment degeneration as presumed. Biomechanical studies with human cadaver lumbar spines are limited and depend on age and degenerative situation. The effect on supporting implants on adjacent segment disease in lumbar spine surgery has to be investigated in clinical long term studies

Introduction. Pedicle screw pullout or loosening is increased in the osteoporotic spine. Recent studies showed a significant increase of pullout forces especially for PMMA-augmentation. With application of conventional viscosity PMMA the risk of cement extravasation is associated. This risk can be reduced by using radiofrequency-responsive, ultrahigh viscosity bone cement. Method. 11 fresh-frozen lumbar vertebral bodies (VB) from 5 cadavers were collected and freed from soft-tissue and ligaments. By DEXA scan (Siemens QDR 2000) 8 VB were identified as severely osteoporotic (BMD 0.8 g/cm3), 3 VB were above this level. Two screws (6×45 mm, WSI-Expertise Inject, Peter Brehm, Weisendorf, Germany) were placed in the pedicles. Through the right screw 3ml of radiofrequency-responsive bone cement (StabiliT® ER2 Bone Cement, DFine, Germany) were injected via hydraulic cement delivery system (StabiliT® Vertebral Augmentation System, DFine, Germany). As control group, left pedicle screws remained uncemented. After potting the whole VB in technical PMMA (Technovit 4004, Heraeus Kulzer, Germany) axial pullout test was performed by a material testing device (Zwick-Roell, Zmart-Pro, Ulm, Germany). Results. The mean BMD of all specimen was 0.771 g/cm3 (min./max. 0.615/1.116, SD ± 0.170). Due to the definition of osteoporosis 8 specimens had a BMD lower than 0.8 g/cm3 (mean 0.677, min./max. 0.615/0,730, SD ±0.045). The non-osteoporotic group consisted of 3 specimens with a mean BMD of 1.020 g/cm3 (min/max 0.928/1.116, SD ±0.094). Overall we observed an increase in the mean axial pullout strength of 284% when using cement augmentated screws (non-cemented 385 N vs. cemented 1029 N, p 0,001). In the osteoporotic group the mean pullout force of the non-cemented screws was 407 N vs. 1022 N for the cemented screws (p 0.001). Similarly the pullout force rose in the non-osteoporotic group from 325 N for the non-cemented screws to 1048 N for the cemented screws p 0,001). All surgical procedures could be performed without technical problems. Conclusion. This cadaver study demonstrates the efficacy and effectiveness of pedicle-screw augmentation with ultra-high viscosity cement. Pullout forces are significantly increased, especially in osteoporotic bone. No complications like clogged in cannulated pedicle-screws or extravasation of bone cement were observed. In daily clinical routine radiation exposure to operator during cement delivery is reduced due to remote-controlled, automated delivery of radiofrequency-responsive bone cement. Furthermore availability of longer time to work with the cement (up to 30 min) is achieved; hectically injection or multiple-cement-mixing is not necessary anymore. The WSI-Expertise cannulated pedicle screws can be inserted and also augmented in a minimal-invasive technique. The PMMA then is injected through an extension adapter. PMMA augmentation of pedicle screws is already well established in spine surgery. With the combination of radiofrequency-responsive, ultra-high viscosity bone cement and cannulated pedicle screws this established procedure could become more controlled and safer for both patient and physician

Objectives

The aim of this systematic literature review was to assess the clinical level of evidence of commercially available demineralised bone matrix (DBM) products for their use in trauma and orthopaedic related surgery.

We reviewed 59 bone graft substitutes marketed by 17 companies currently available for implantation in the United Kingdom, with the aim of assessing the peer-reviewed literature to facilitate informed decision-making regarding their use in clinical practice. After critical analysis of the literature, only 22 products (37%) had any clinical data. Norian SRS (Synthes), Vitoss (Orthovita), Cortoss (Orthovita) and Alpha-BSM (Etex) had Level I evidence. We question the need for so many different products, especially with limited published clinical evidence for their efficacy, and conclude that there is a considerable need for further prospective randomised trials to facilitate informed decision-making with regard to the use of current and future bone graft substitutes in clinical practice.

Cite this article: Bone Joint J 2013;95-B:583–97.