Implant contamination as a cause of surgical site infection in spinal surgery: are single-use implants a reasonable solution? – a systematic review

Background: In spine surgery, surgical site infection (SSI) is one of the main perioperative complications and is associated with a higher patient morbidity and longer patient hospitalization. Most factors associated with SSI are connected with asepsis during the surgical procedure and thus with contamination of implants and instruments used which can be caused by pre- and intraoperative factors. In this systematic review we evaluate the current literature on these causes and discuss possible solutions to avoid implant and instrument contamination. Methods: A systematic literature search of PubMed addressing implant, instrument and tray contamination in orthopaedic and spinal surgery from 2001 to 2019 was conducted following the PRISMA guidelines. All studies regarding implant and instrument contamination in orthopaedic surgery published in English language were included. Results: Thirty-five studies were eligible for inclusion and were divided into pre- and intraoperative causes for implant and instrument contamination. Multiple studies showed that reprocessing of medical devices for surgery may be insufficient and lead to surgical site contamination. Regarding intraoperative causes, contamination of gloves and gowns as well as contamination via air are the most striking factors contributing to microbial contamination. Conclusions: Our systematic literature review shows that multiple factors can lead to instrument or implant contamination. Intraoperative causes of contamination can be avoided by implementing behavior such as changing gloves right before handling an implant and reducing the instruments' intraoperative exposure to air. In avoidance of preoperative contamination, there still is a lack of convincing evidence for the use of single-use implants in orthopaedic surgery

The Impact of Spinopelvic Mobility on Arthroplasty: Implications for Hip and Spine Surgeons

Spinopelvic mobility represents the complex interaction of hip, pelvis, and spine. Understanding this interaction is relevant for both arthroplasty and spine surgeons, as a predicted increasing number of patients will suffer from hip and spinal pathologies simultaneously. We conducted a comprehensive literature review, defined the nomenclature, summarized the various classifications of spinopelvic mobility, and outlined the corresponding treatment algorithms. In addition, we developed a step-by-step workup for spinopelvic mobility and total hip arthroplasty (THA). Normal spinopelvic mobility changes from standing to sitting; the hip flexes, and the posterior pelvic tilt increases with a concomitant increase in acetabular anteversion and decreasing lumbar lordosis. Most classifications are based on a division of spinopelvic mobility based on ΔSS (sacral slope) into stiff, normal, and hypermobile, and a categorization of the sagittal spinal balance regarding pelvic incidence (PI) and lumbar lordosis (LL) mismatch (PI-LL = ± 10° balanced versus PI-LL > 10° unbalanced) and corresponding adjustment of the acetabular component implantation. When performing THA, patients with suspected pathologic spinopelvic mobility should be identified by medical history and examination, and a radiological evaluation (a.p. pelvis standing and lateral femur to L1 or C7 (if EOS (EOS imaging, Paris, France) is available), respectively, for standing and sitting radiographs) of spinopelvic parameters should be conducted in order to classify the patient and determine the appropriate treatment strategy. Spine surgeons, before planned spinal fusion in the presence of osteoarthritis of the hip, should consider a hip flexion contracture and inform the patient of an increased risk of complications with existing or planned THA

Acetabular cup position differs in spinopelvic mobility types: a prospective observational study of primary total hip arthroplasty patients

Introduction: Spinopelvic mobility was identified as a contributing factor for total hip arthroplasty (THA) instability. The influence of spinopelvic function on acetabular cup positioning has not yet been sufficiently investigated in a prospective setting. Therefore, our study aimed (1) to assess cup inclination and anteversion in standing and sitting based on spinopelvic mobility, (2) to identify correlations between cup position and spinopelvic function, (3) and to determine the influence of the individual spinal segments, spinal sagittal balance, and spinopelvic characteristics on the mobility groups. Materials and methods: A prospective study assessing 197 THA patients was conducted with stereoradiography in standing and sitting position postoperatively. Two independent investigators determined cup anteversion and inclination, C7-Sagittal vertical axis, cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope, pelvic tilt (PT), anteinclination (AI), and pelvic femoral angle (PFA). Spinopelvic mobility is defined based on increment PT = PTstanding - PTsitting as increment PT = 10-30 degrees normal, and increment PT > 30 degrees hypermobile. Pearson coefficient represented correlations between the cup position and spinopelvic parameters. Results: Significant differences were demonstrated for cup anteversion (stiff/hypermobile 29.3 degrees/40.1 degrees; p < 0.000) and inclination (stiff/hypermobile 43.5 degrees/60.2 degrees; p < 0.000) in sitting, but not in standing position. increment (standing/sitting) of the cup anteversion (stiff/neutral/hypermobile 5.8 degrees/12.4 degrees/19.9 degrees; p < 0.000) and inclination (stiff/neutral/hypermobile 2.3 degrees/11.2 degrees/18.8 degrees; p < 0.000) revealed significant differences between the mobility groups. The acetabular cup position in sitting, was correlated with lumbar flexibility ( increment LL) and spinopelvic mobility. Significant differences were detected between the mobility types and acetabular orientation (AI sit:stiff/hypermobile 47.6 degrees/65.4 degrees; p < 0.000) and hip motion ( increment PFA:stiff/hypermobile 65.8 degrees/37.3 degrees; p < 0.000). Assessment of the spinal segments highlighted the role of lumbar flexibility ( increment LL:stiff/hypermobile 9.9 degrees/36.2 degrees; p < 0.000) in the spinopelvic complex. Conclusion: The significantly different acetabular cup positions in sitting and in the increment between standing and sitting and the significantly altered spinopelvic characteristics in terms of stiff and hypermobile spinopelvic mobility underlined the consideration for preoperative functional radiological assessment. Identifying the patients with altered spinopelvic mechanics due to a standardized screening algorithm is necessary to provide safe acetabular cup positioning. The proximal spinal segments appeared not to be involved in the spinopelvic function

Spinal Deformity Surgery: A Critical Review of Alignment and Balance

Correction of the overall coronal and/or sagittal plane deformities is one of the main predictors of successful spinal surgery. In routine clinical practice, spinal alignment is assessed using several spinal and pelvic parameters, such as pelvic incidence and tilt, sacral slope, lumbar lordosis, thoracic kyphosis, and sagittal vertical axis. Standard values have been defined for all these parameters, and the formulas of correction have been set for determining the surgical strategy. However, several factors can potentially bias these formulas. First, all standard values are measured using conventional plain radiographs and are, therefore, prone to bias. The radiologist, measuring surgeon, and patient are possible confounding influencing factors. Second, spino-pelvic compensatory effects and biomechanically relevant structures for the patient’s posture, including ligaments, tendons, and muscles, have received minimal consideration in the literature. Therefore, even in cases of appropriately planned deformity correction surgeries, complications, revision rates, and surgical outcomes significantly vary. This study aimed to illustrate the current clinical weaknesses of the assessment of spinal alignment and the importance of holistically approaching the musculoskeletal system for any spinal deformity surgery. We believe that our detailed insights regarding spinal, sagittal, and coronal alignments as well as the considerations of an individual’s spinal balance will contribute toward improvement in routine patient care

An Uncemented Spreading Stem for the Fixation in the Metaphyseal Femur: A Preliminary Report

Surgical treatment to restore full range of motion and full weight bearing after extensive femoral bone resection in patients with primary or metastatic femoral tumours is individually challenging. Especially when the remaining distal or proximal bone is very short, a rigid fixation of an implant is difficult to achieve due to the reverse funnel shape of the metaphysis. Herein, we present a novel implant design using a spreading mechanism in the distal part of the prosthesis for rigid, uncemented fixation in the remaining femoral bone after extensive tumour resection of the femur. We present the outcome of 5 female patients who underwent implantation of this spreading stem after extensive proximal or distal femoral bone resection. There was no radiological or clinical loosening or implant-related revision surgery in our follow-up (mean 21.46 months, range 3.5–46 months). This uncemented spreading stem may therefore represent an alternative option for fixation of a prosthetic device in the remaining metaphyseal femur

Two-stage revision for periprosthetic joint infection in cemented total hip arthroplasty: an increased risk for failure?

Background: The impact of the prior fixation mode on the treatment outcome of chronic periprosthetic joint infection (PJI) of the hip is unclear. Removal of cemented total hip arthroplasty (THA) is particularly challenging and residual cement might be associated with reinfection. This study seeks to compare the results of two-stage revision for PJI in cemented and cementless THA. Methods: We reviewed 143 consecutive patients undergoing two-stage revision THA for PJI between 2013 and 2018. Thirty-six patients with a fully cemented (n = 6), hybrid femur (n = 26) or hybrid acetabulum (n = 4) THA (cemented group) were matched 1:2 with a cohort of 72 patients who underwent removal of a cementless THA (cementless group). Groups were matched by sex, age, number of prior surgeries and history of infection treatment. Outcomes included microbiological results, interim re-debridement, reinfection, all-cause revision, and modified Harris hip scores (mHHS). Minimum follow-up was 2 years. Results: Compared with PJI in cementless THA, patients undergoing removal of cemented THA had increasingly severe femoral bone loss (p = 0.004). Patients in the cemented group had an increased risk for positive cultures during second-stage reimplantation (22% compared to 8%, p = 0.043), higher rates of reinfection (22% compared to 7%, p = 0.021) and all-cause revision (31% compared to 14%, p = 0.039) compared to patients undergoing two-stage revision of cementless THA. Periprosthetic femoral fractures were more frequent in the group of patients with prior cementation (p = .004). Mean mHHS had been 37.5 in the cemented group and 39.1 in the cementless group, and these scores improved significantly in both groups (p < 0.01). Conclusion: This study shows that chronic infection in cemented THA might be associated with increased bone loss, higher rates of reinfection and all-cause revision following two-stage revision. This should be useful to clinicians counselling patients with hip PJI and can guide treatment and estimated outcomes

Validation of the TLICS and AOSpine injury score for surgical management of paediatric traumatic spinal injuries

Introduction Fractures of the thoracolumbar spine in children are rare. Consequently, classification systems providing detailed treatment recommendations as already established in adults are still lacking in the paediatric population. We aimed to evaluate the validity and reliability of the thoracolumbar injury classification and severity score system (TLICS) and the AOSpine injury score in paediatric patients presenting with a traumatic fracture of the thoracolumbar spine. Materials and methods Patients younger than 18 years presenting with a traumatic thoracolumbar fracture at a large academic trauma centre between 2010 and 2020 were included retrospectively. Demographic and clinical data were retrieved from electronic medical reports. The AOSpine injury score and TLICS were calculated using plain radiography, magnetic resonance imaging, and/or computed tomography. Results Sixty patients with 167 fractures were included. Surgical treatment was performed in 14 patients. The mean AOSpine injury score was 1.49 +/- 2.0, the mean TLICS was 1.32 +/- 1.65. A significant correlation between the classification systems was found (Spearman r = 0.975, p < 0.001). Interrater reliability analysis revealed Kappa values of 0.868 for the TLICS and 0.860 for the AOSpine injury score (p < 0.001). Contingency table analysis showed a sensitivity of 1.00 and specificity of 0.94 for the AOSpine injury score and a sensitivity of 0.90 and specificity of 0.90 for the TLICS in predicting the performed treatment. Conclusions Our results confirm that the TLICS is a valid classification system for determining treatment decisions in paediatric patients and show slightly higher accuracy of the AOSpine injury score as well as high interrater reliabilities for both classification systems

Kyphoplasty Restores the Global Sagittal Balance of the Spine Independently from Pain Reduction

Kyphoplasty is the standard surgical treatment of vertebral compression fractures. We aimed to clarify the influence of kyphoplasty on the sagittal profile as well as the relation between posture improvement and pain relief. For this purpose, we evaluated various radiological parameters of the sagittal profile on whole spine standing radiographs of 73 Patients with a single vertebral fracture treated by kyphoplasty. The key outcome was the postoperative change of the sagittal vertical axis (SVA). Additionally, clinical parameters including pain scores on visual analogue scale (VAS) and use of analgesics were obtained from medical records. Pre- and postoperative radiological as well as clinical parameters were compared. Additionally, the correlation between changes of SVA and changes of local kyphotic angle (LKA) or VAS was examined. The clinical parameters as well as various radiographic parameters (SVA, LKA, Gardner, Cobb) improved significantly postoperatively. The improvement of SVA correlated significantly with the correction of the LKA but not with postoperative pain relief. We conclude that kyphoplasty helps to restore the global sagittal balance of the spine after vertebral fractures. The correction of the sagittal profile seems to depend on the correction of the local kyphotic angle but does not correlate with postoperative pain relief

Total hip arthroplasty for destructive septic arthritis of the hip using a two-stage protocol without spacer placement

Introduction: The optimal treatment of patients with a degenerative joint disease secondary to an active or chronic septic arthritis of the hip is unclear. The aim of the present study was to report on our experience with two-stage total hip arthroplasty (THA) using a contemporary treatment protocol without spacer insertion. Materials and methods: Our prospective institutional database was used to identify all patients with degenerative septic arthritis treated with a non-spacer two-stage protocol between 2011 and 2017. Clinical outcomes included interim revision, periprosthetic infection (PJI) and aseptic revision rates. Restoration of leg-length and offset were assessed radiographically. Modified Harris hip score (mHHS) were obtained. Treatment success was defined using the modified Delphi consensus criteria. Mean follow-up was 62 months (13-110). Results: A total of 33 patients with a mean age of 60 years (13-85) were included. 55% of the cohort was male and average Charlson Comorbidity Index (CCI) was 3.7 (0-12). 21 patients (64%) had an active/acute infection and 12 patients (36%) were treated for chronic/quiescent septic arthritis. Overall, 11 patients (33%) had treatment failure, including 5 patients who failed to undergo THA, 2 interim re-debridement for persistent infection, and 4 patients who developed PJI after an average of 7 months (0.3-13) following THA. The most common identified pathogen was Staphylococcus aureus (42.4%). No aseptic revision was recorded following THA. Leg-length and offset were successfully restored. Mean mHHS improved from 35.2 points to 73.4 points. Conclusion: Two-stage THA without spacer placement is a viable treatment option for destructive septic arthritis of the hip, demonstrating comparable rates of infection control and functional outcome. However, definitive resection arthroplasty is not uncommon in these often critically ill patients

Comparison of three validated systems to analyse spinal shape and motion

The assessment of spinal shape and mobility is of great importance for long-term therapy evaluation. As frequent radiation should be avoided, especially in children, non-invasive measurements have gained increasing importance. Their comparability between each other however stays elusive. Three non-invasive measurement tools have been compared to each other: Idiag M360, raster stereography and Epionics SPINE. 30 volunteers (15 females/15 males) have each been assessed by each system, investigating lumbar lordosis, thoracic kyphosis and spinal range-of-motion in the sagittal plane. Lumbar lordosis differed significantly (p < 0.001) between measurement devices but correlated significant to each other (Pearson's r 0.5-0.6). Regarding thoracic kyphosis no significant difference and a high correlation (r = 0.8) could be shown between Idiag M360 and raster stereography. For lumbar mobility resulting measurements differed significantly and correlated only moderate between Idiag M360 and Epionics SPINE. Although the different measurement systems are moderate to high correlated to each other, their absolute agreement is limited. This might be explained by differences in their angle definition for lordotic and kyphotic angle, their measurement placement, or their capturing of mobility (static vs. dynamic assessment). Therefore, for long-term evaluation of the back profile, inter-modal comparison of values between different non-invasive devices should be avoided