90-Day Emergency Department Utilization and Readmission Rate After Full-Endoscopic Spine Surgery: A Multicenter, Retrospective Analysis of 821 Patients.

BACKGROUND AND OBJECTIVES: Emergency department (ED) utilization and readmission rates after spine surgery are common quality of care measures. Limited data exist on the evaluation of quality indicators after full-endoscopic spine surgery (FESS). The objective of this study was to detect rates, causes, and risk factors for unplanned postoperative clinic utilization after FESS. METHODS: This retrospective multicenter analysis assessed ED utilization and clinic readmission rates after FESS performed between 01/2014 and 04/2023 for degenerative spinal pathologies. Outcome measures were ED utilizations, hospital readmissions, and revision surgeries within 90 days postsurgery. RESULTS: Our cohort includes 821 patients averaging 59 years of age, who underwent FESS. Most procedures targeted the lumbar or sacral spine (85.75%) while a small fraction involved the cervical spine (10.11%). The most common procedures were lumbar unilateral laminotomies for bilateral decompression (40.56%) and lumbar transforaminal discectomies (25.58%). Within 90 days postsurgery, 8.0% of patients revisited the ED for surgical complications. A total of 2.2% of patients were readmitted to a hospital of which 1.9% required revision surgery. Primary reasons for ED visits and clinic readmissions were postoperative pain exacerbation, transient neurogenic bladder dysfunction, and recurrent disk herniations. Our multivariate regression analysis revealed that female patients had a significantly higher likelihood of using the ED (P = .046; odds ratio: 1.77, 95% CI 1.01-3.1 5.69% vs 10.33%). Factors such as age, American Society of Anesthesiologists class, body mass index, comorbidities, and spanned spinal levels did not significantly predict postoperative ED utilization. CONCLUSION: This analysis demonstrates the safety of FESS, as evidenced by acceptable rates of ED utilization, clinic readmission, and revision surgery. Future studies are needed to further elucidate the safety profile of FESS in comparison with traditional spinal procedures.

Perioperative complications associated with fluoroscopy C1 lateral mass screw fixation (Goel technique) versus computed tomography-guided navigation technique: A review of 202 cases from the German Spine Registry (DWG-Register).

Background: Overview of the literature - Fractures of the C1 constitute 3%-13% of all cervical spine injuries in adults. Most isolated C1 fractures are stable and can be treated nonoperatively with external immobilization. Traditional surgical options for C1 fracture treatment are occiput-to-C2 fusion or C1 with lateral mass screws (LMSs). Purpose - The aim is to assess the management and perioperative complications of C1 fractures undergoing LMS fusion between fluoroscopy and computed tomography (CT)-guided navigation. Methods: This was a retrospective multicenter study of data from the DWG-Register of patients who underwent operative treatment for C1 traumatic fracture with LMSs from January 2017 to September 2022. Inclusion criteria - traumatic injury and age > 18 years old. Results: In total, 202 patients with traumatic C1 fracture requiring spinal surgery were identified in the registry; n = 175 (Group 1) were treated conventionally without CT-guided navigation and n = 27 were treated with CT-guided navigation (Group 2). C1-LMS was principally performed by spine surgeons n = 90 (53.4%) and n = 72 (18.5%) by neurosurgeons in both the groups. Intraoperative adverse events were as follows: dural tear in group 1 n = 0 and in group 2 n = 1, vascular injury, with one case in group 1 and no cases in group 2. General complications were: cardiovasculars in group 1 n = 6 (3.4%) and Group 2 n = 4 (14.8%) (P = 0.03), pulmonary complications in group1 n = 2 (1.1%) and n = 9 in group 2 (33.3%) (P < 0.001), stroke n = 1 (0.57%) in group1 and n = 4 in group 2 (14.8%) (P < 0.001), gastrointestinal bleeding n = 1 (0.57%) in group1 and no cases in group 2, renal insufficiency n = 2 (1.1%) in group 1 and n = 3 (11.1%) in group 2 (P = 0.01). One death was recorded in group 2 (3.7%). Conclusion: This series of 404 screws placed in 202 patients over 5 years who underwent two types of C1 fracture fixation had a considerably lower incidence of screw malposition and vertebral artery injury than has previously been reported in the literature. C1 screws can be safely placed with a low risk of vertebral artery and neurologic injury with and without CT-guided navigation support.

Infective endocarditis and spondylodiscitis-impact of sequence of surgical therapy on survival and recurrence rate.

OBJECTIVES: To date, there are no standardized treatment algorithms or recommendations for patients with infective endocarditis (IE) and concomitant spondylodiscitis (SD). Therefore, our aim was to analyse whether the sequence of surgical treatment of IE and SD has an impact on postoperative outcome and to identify risk factors for survival and postoperative recurrence. METHODS: Patients with IE underwent surgery in 4 German university hospitals between 1994 and 2022. Univariable and multivariable analyses were performed to identify possible predictors of 30-day/1-year mortality and recurrence of IE and/or SD. RESULTS: From the total IE cohort (n = 3991), 150 patients (4.4%) had concomitant SD. Primary surgery for IE was performed in 76.6%, and primary surgery for SD in 23.3%. The median age was 70.0 (64.0-75.6) years and patients were mostly male (79.5%). The most common pathogens detected were enterococci and Staphylococcus aureus followed by streptococci, and coagulase-negative Staphylococci. If SD was operated on first, 30-day mortality was significantly higher than if IE was operated on 1st (25.7% vs 11.4%; P = 0.037) and we observed a tendency for a higher 1-year mortality. If IE was treated 1st, we observed a higher recurrence rate within 1 year (12.2% vs 0%; P = 0.023). Multivariable analysis showed that primary surgery for SD was an independent predictor of 30-day mortality. CONCLUSIONS: Primary surgical treatment for SD was an independent risk factor for 30-day mortality. When IE was treated surgically 1st, the recurrence rate of IE and/or SD was higher.

Endoscopic Versus Traditional Thoracic Discectomy: A Multicenter Retrospective Case Series and Meta-Analysis.

BACKGROUND AND OBJECTIVES: Surgical treatment for symptomatic thoracic disc herniations (TDH) involves invasive open surgical approaches with relatively high complication rates and prolonged hospital stays. Although advantages of full endoscopic spine surgery (FESS) are well-established in lumbar disc herniations, data are limited for the endoscopic treatment of TDH despite potential benefits regarding surgical invasiveness. The aim of this study was to provide a comprehensive evaluation of potential benefits of FESS for the treatment of TDH. METHODS: PubMed, MEDLINE, EMBASE, and Scopus were systematically searched for the term "thoracic disc herniation" up to March 2023 and study quality appraised with a subsequent meta-analysis. Primary outcomes were perioperative complications, need for instrumentation, and reoperations. Simultaneously, we performed a multicenter retrospective evaluation of outcomes in patients undergoing full endoscopic thoracic discectomy. RESULTS: We identified 3190 patients from 108 studies for the traditional thoracic discectomy meta-analysis. Pooled incidence rates of complications were 25% (95% CI 0.22-0.29) for perioperative complications and 7% (95% CI 0.05-0.09) for reoperation. In this cohort, 37% (95% CI 0.26-0.49) of patients underwent instrumentation. The pooled mean for estimated blood loss for traditional approaches was 570 mL (95% CI 477.3-664.1) and 7.0 days (95% CI 5.91-8.14) for length of stay. For FESS, 41 patients from multiple institutions were retrospectively reviewed, perioperative complications were reported in 4 patients (9.7%), 4 (9.7%) required revision surgery, and 6 (14.6%) required instrumentation. Median blood loss was 5 mL (IQR 5-10), and length of stay was 0.43 days (IQR 0-1.23). CONCLUSION: The results suggest that full endoscopic thoracic discectomy is a safe and effective treatment option for patients with symptomatic TDH. When compared with open surgical approaches, FESS dramatically diminishes invasiveness, the rate of complications, and need for prolonged hospitalizations. Full endoscopic spine surgery has the capacity to alter the standard of care for TDH treatment toward an elective outpatient surgery.

Thermographic assessment of skin temperature after lumbar spine surgery: Useful method for detection of wound complications? A pilot study.

BACKGROUND: Wound complications after lumbar spine surgery may result in prolonged hospitalization and increased morbidity. Early identification can trigger appropriate management. OBJECTIVE: The aim of this study was to investigate the efficacy of infrared-based wound assessment (FLIR) after lumbar spine surgery in the context of identifying wound healing disorders. METHODS: 62 individuals who underwent lumbar spine surgery were included. The immediate postoperative course was studied, and the patient's sex, age, body mass index (BMI), heart rate, blood pressure, body temperature, numeric rating scale for pain (NRS), C-reactive protein (CRP), leukocyte, and hemoglobin levels were noted and compared to thermographic measurement of local surface temperature in the wound area. RESULTS: Measurement of local surface temperature in the wound area showed a consistent temperature distribution while it was uneven in case of wound healing disorder. In this instance, the region of the wound where the wound healing disorder occured had a lower temperature than the surrounding tissue (p> 0.05). CONCLUSIONS: This study demonstrates the ongoing importance of clinical wound assessment for early detection of complications. While laboratory parameter measurement is crucial, FLIR may serve as a cost-effective supplemental tool in clinical wound evaluation. Patient safety risks appear minimal since local ST is measured without touch.

An investigation into the quality of life improvements after vertebral osteomyelitis depending on the status of pathogen detection.

OBJECTIVE: This study aimed to compare clinical characteristics and quality of life (QoL) after vertebral osteomyelitis (VO) based on the status of pathogen detection in microbiological sampling. METHODS: We conducted a post hoc data analysis from a prospective single-center study in a tertiary referral hospital, including VO patients from 2008 to 2020. Data were collected preoperatively (T0) and 1-year post surgery (T1). The primary outcome was QoL, assessed with the Oswestry Disability Index and Core Outcome Measures Index. RESULTS: Data from 133 patients with surgically treated thoracic or lumbar VO were evaluated. The pathogen was detected from cultured intraoperative samples in 100 (75.2%) patients (group 1). Culture remained negative in 33 (24.8%) patients (group 2). Quality of life did not differ significantly between the groups at T1. We observed higher preoperative C-reactive protein values and higher rates of spinal empyema at T0 in group 1. CONCLUSION: Quality of life improved significantly for all patients at T1, but scores remained comparable to those reported by patients with chronic back pain. Quality of life was not affected by pathogen detection. However, attempts to detect pathogens are still indicated due to the concomitant findings, including bacteremia and epidural abscesses, along with the advantages of targeted antibiotic therapy. The most critical step for detection may be avoiding pre-sampling antibiotic administration. Cite this article as: Beyer F, Wenk B, Jung N, Bredow J, Eysel P, Yagdiran A. An investigation into quality of life improvements after vertebral osteomyelitis depending on the status of pathogen detection. Acta Orthop Traumatol Turc., 2024; 10.5152/j.aott.2024.23073 [Epub Ahead of Print].

Preoperative Performance Status Threshold for Favorable Surgical Outcome in Metastatic Spine Disease.

BACKGROUND AND OBJECTIVES: Surgical treatment is an integral component of multimodality management of metastatic spine disease but must be balanced against the risk of surgery-related morbidity and mortality, making tailored surgical counseling a clinical challenge. The aim of this study was to investigate the potential predictive value of the preoperative performance status for surgical outcome in patients with spinal metastases. METHODS: Performance status was determined using the Karnofsky Performance Scale (KPS), and surgical outcome was classified as "favorable" or "unfavorable" based on postoperative changes in neurological function and perioperative complications. The correlation between preoperative performance status and surgical outcome was assessed to determine a KPS-related performance threshold. RESULTS: A total of 463 patients were included. The mean age was 63 years (range: 22-87), and the mean preoperative KPS was 70 (range: 30-100). Analysis of clinical outcome in relation to the preoperative performance status revealed a KPS threshold between 40% and 50% with a relative risk of an unfavorable outcome of 65.7% in KPS ≤40% compared with the relative chance for a favorable outcome of 77.1% in KPS ≥50%. Accordingly, we found significantly higher rates of preserved or restored ambulatory function in KPS ≥50% (85.7%) than in KPS ≤40% (48.6%; P < .001) as opposed to a significantly higher risk of perioperative mortality in KPS ≤40% (11.4%) than in KPS ≥50% (2.1%, P = .012). CONCLUSION: Our results underline the predictive value of the KPS in metastatic spine patients for counseling and decision-making. The study suggests an overall clinical benefit of surgical treatment of spinal metastases in patients with a preoperative KPS score ≥50%, while a high risk of unfavorable outcome outweighing the potential clinical benefit from surgery is encountered in patients with a KPS score ≤40%.

The projected increase of vertebral osteomyelitis in Germany implies a demanding challenge for future healthcare management of aging populations.

PURPOSE: Since an increase in the occurrence of native vertebral osteomyelitis (VO) is expected and reliable projections are missing, it is urgent to provide a reliable forecast model and make it a part of future health care considerations. METHODS: Comprehensive nationwide data provided by the Federal Statistical Office of Germany were used to forecast total numbers and incidence rates (IR) of VO as a function of age and gender until 2040. Projections were done using autoregressive integrated moving average model on historical data from 2005 to 2019 in relation to official population projections from 2020 to 2040. RESULTS: The IR of VO is expected to increase from 12.4 in 2019 to 21.5 per 100,000 inhabitants [95% CI 20.9-22.1] in 2040. The highest increase is predicted in patients over 75 years of age for both men and women leading to a steep increase in absolute numbers, which is fourfold higher compared to patients younger than 75 years. While the IR per age group will not increase any further after 2035, the subsequent increase is due to a higher number of individuals aged 75 years or older. CONCLUSIONS: Our data suggest that increasing IR of VO will seriously challenge healthcare systems, particularly due to demographic change and increasing proportions of populations turning 75 years and older. With respect to globally fast aging populations, future health care policies need to address this burden by anticipating limitations in financial and human resources and developing high-level evidence-based guidelines for prevention and interdisciplinary treatment.

How Preoperative Closed Reduction and Time to Surgery Impact Postoperative Palmar Inclination in Distal Radius Fractures.

Background: The anatomical reconstruction of the wrist is the aim when treating distal radius fractures. Current literature on the importance of preoperative reduction in fractures that are treated operatively is limited. Methods: This study investigated the effect of the preoperative closed reduction of distal radius fractures on the day of trauma and the time to surgery on postoperative palmar inclination. A total of eighty patients (48 females and 32 males, mean age 55.6 years) were studied retrospectively. All patients were treated with an open reduction and internal fixation. The palmar inclination angle was measured using X-rays by two investigators, and the interobservers and pre- and post-reduction parameters were compared. Results: When the surgical management of closed distal radius fractures is required, neither initial repositioning nor a delay of up to 14 days to the surgical treatment influences postoperative palmar inclination. Conclusions: The significance of preoperative reduction of distal radius fractures without neurovascular or extensive soft tissue damage is limited and is not leading to improved outcomes. When surgery is about to be performed, surgeons should carefully consider if reduction is really vital preoperatively. Level of evidence: III.

Torque forces of expandable titanium vertebral body replacement cages during expansion and subsidence in the osteoporotic lumbar spine.

BACKGROUND: The application of expandable titanium-cages has gained widespread use in vertebral body replacement for indications such as burst fractures, tumors and infectious destruction. However, torque forces necessary for a satisfactory expansion of these implants and for subsidence of them into the adjacent vertebrae are unknown within the osteoporotic spine. METHODS: Six fresh-frozen human, osteoporotic, lumbar spines were dorsally instrumented with titanium implants (L2-L4) and a partial corpectomy of L3 was performed. An expandable titanium-cage was inserted ventrally and expanded by both residents and senior surgeons until fixation was deemed sufficient, based on haptic feedback. Torque forces for expansion were measured in Nm. Expansion was then continued until cage subsidence occurred. Torque forces necessary for subsidence were recorded. Strain of the dorsal rods during expansion was measured with strain gauges. FINDINGS: The mean torque force for fixation of cages was 1.17 Nm (0.9 Nm for residents, 1.4 Nm for senior surgeons, p = .06). The mean torque force for subsidence of cages was 3.1 Nm (p = .005). Mean peak strain of the dorsal rods was 970 µm/m during expansion and 1792 µm/m at subsidence of cages (p = .004). INTERPRETATION: The use of expandable titanium-cages for vertebral body replacement seems to be a primarily safe procedure even within the osteoporotic spine as torque forces required for subsidence of cages are nearly three times higher than those needed for fixation. Most of the expansion load is absorbed by straining of the dorsal instrumentation. Rod materials other than titanium may alter the torque forces found in this study.

Economic Implications of Dural Tears in Lumbar Microdiscectomies: A Retrospective, Observational Study.

OBJECTIVE: Dural tears (DTs) are a frequent complication after lumbar spine surgery. We sought to determine the incidence of DTs and the related impact on health care expenditures after lumbar discectomies. METHODS: In this retrospective cohort study, all patients with first-time single-level lumbar discectomies at our institution who underwent minimally invasive surgery from 2015 to 2019 were reviewed. Age, sex, weight, height, body mass index, costs, revenues, length of stay, American Society of Anesthesiologists score, Charlson Comorbidity Index, and operative time (OT) were assessed. Exclusion criteria were age <18 years, previous spine surgery, multiple or traumatic disc herniations, and malignant and infectious diseases. RESULTS: The follow-up time was at least 12 months postoperatively. Of 358 patients identified with lumbar discectomies, 230 met the inclusion criteria. Incidence of DTs was 3.5%. Mean costs (P < 0.001), economic loss (P < 0.01), and OT (P < 0.0001) were found to be significantly higher in the DT group compared with the control group of patients without a DT. The revenues were not statistically different between the 2 groups (P > 0.05). Further analysis of the control group by profit and loss revealed significantly higher body mass index (P < 0.05), length of stay (P < 0.0001), and OT (P < 0.0001) in the loss group. CONCLUSIONS: DTs represent a significant socioeconomic burden in lumbar spine surgery and cause severe secondary complications. The impact of DTs on health care expenses is primarily based on significantly higher OT and a higher mean length of stay.

Smartphone applications for remote patient monitoring reduces clinic utilization after full-endoscopic spine surgery.

INTRODUCTION: The rising number of outpatient spine surgeries creates challenges in postoperative management and care. Telemedicine offers a unique opportunity to reduce in-person clinic visits and improve resource allocation. We aimed to investigate the impact of a validated smartphone application on clinic utilization following full-endoscopic spine surgery (FESS). METHODS: We evaluated patients undergoing FESS from 2020 to 2022 and a pre-COVID control group (CG) from 2018 to 2019. Subsequently, we divided the patients into three groups: one using the application (intervention group, IG), and two CGs (2020-2022, CG and 2018-2019, historical control group (HG)). We analyzed the post-surgical hospitalization rate, all follow-ups, and virtually transmitted patient-reported outcomes. RESULTS: A total of 115 patients were included in the IG. The CG consisted of 137 and the HG of 202 patients (CG and HG in the following). Group homogeneity was satisfactory regarding patient age (p = 0.9), sex (p = 0.88), and body mass index (p = 0.99). IG patients were treated as outpatients significantly more often [14.78% vs. 29.2% vs. 37.62% (p < 0.001)]. Additionally, IG patients showed significantly higher follow-up compliance [74.78% vs. 40.14% vs. 37.13% (p < 0.001)] 3-month post-surgery and fewer in-patient follow-up visits [(0.5 ± 0.85 vs. 1.32 ± 0.8 vs. 1.33 ± 0.7 (p < 0.001)]. CONCLUSION: Our results underline the feasibility, efficacy, and safety of remote patient monitoring following FESS. Furthermore, they highlight the opportunity to implement a virtual wound checkup, and to substantially improve postoperative follow-up compliance via telemedicine.

Pain alleviation and functional improvement: ultra-early patient-reported outcome measures after full endoscopic spine surgery.

OBJECTIVE: Questions regarding anticipated pain improvement and functional recovery postsurgery are frequently posed in preoperative consultations. However, a lack of data characterizing outcomes for the first postoperative days only allows for anecdotal answers. Hence, the assessment of ultra-early patient-reported outcome measures (PROMs) is essential for patient-provider communication and patient satisfaction. The aim of this study was to elucidate this research gap by assessing and characterizing PROMs for the first days after full endoscopic spine surgery (FESS). METHODS: This multicenter study included patients undergoing lumbar FESS from March 2021 to July 2023. After informed consent was provided, data were collected prospectively through a smartphone application. Patients underwent either discectomy or decompression. Analyzed parameters included demographics, surgical details, visual analog scale scores for both back and leg pain, and the Oswestry Disability Index (ODI) score. Data were acquired daily for the 1st postoperative week, as well as after 2 weeks, 3 months, and 6 months. RESULTS: A total of 182 patients were included, of whom 102 underwent FESS discectomy and 80 underwent FESS decompression. Significant differences between the discectomy and decompression groups were found for age (mean 50.45 ± 15.28 years and 63.85 ± 13.25 years, p < 0.001; respectively), sex (p = 0.007), and surgery duration (73.45 ± 45.23 minutes vs 98.05 ± 46.47 minutes, p < 0.001; respectively). Patients in both groups reported a significant amelioration of leg pain on the 1st postoperative day (discectomy group VAS score: 6.2 ± 2.6 vs 2.4 ± 2.9, p < 0.001; decompression group: 5.3 ± 2.8 vs 1.9 ± 2.2, p < 0.001) and of back pain within the 1st postoperative week (discectomy group VAS score: 5.5 ± 2.8 vs 2.8 ± 2.2, p < 0.001; decompression group: 5.2 ± 2.7 vs 3.1 ± 2.4, p < 0.001). ODI score improvement was most pronounced at the 3-month time point (discectomy group: 21.7 ± 9.1 vs 9.3 ± 9.1, p < 0.001; decompression group: 19.3 ± 7.8 vs 9.9 ± 8.3, p < 0.001). For both groups, pain improvement within the 1st week after surgery was highly predictive of later benefits. CONCLUSIONS: Ultra-early PROMs reveal an immediate pain improvement after FESS. While the benefits in pain reduction plateaued within the 1st postoperative week for both groups, functional improvements developed over a more extended period. These results illustrate a biphasic rehabilitation process wherein initial pain alleviation transitions into functional improvement over time.

Assessing the impact of obesity on full endoscopic spine surgery: surgical site infections, surgery durations, early complications, and short-term functional outcomes.

OBJECTIVE: An increasing number of obese patients undergoing elective spine surgery has been reported. Obesity has been associated with a substantially higher number of surgical site infections and a longer surgery duration. However, there is a lack of research investigating the intersection of obesity and full endoscopic spine surgery (FESS) in terms of functional outcomes and complications. The aim of this study was to evaluate wound site infections and functional outcomes following FESS in obese patients. METHODS: Patients undergoing lumbar FESS at the participating institutions from March 2020 to March 2023 for degenerative pathologies were included in the analysis. Patients were divided into obese (BMI > 30 kg/m2) and nonobese (BMI 18-30 kg/m2) groups. Data were collected prospectively using an approved smartphone application for 3 months postsurgery. Parameters included demographics, surgical details, a virtual wound checkup, the visual analog scale for back and leg pain, and the Oswestry Disability Index (ODI) as a functional outcome measure. RESULTS: A total of 118 patients were included in the analysis, with 53 patients in the obese group and 65 in the nonobese group. Group homogeneity was satisfactory regarding patient age (obese vs nonobese: 55.5 ± 14.7 years vs 59.1 ± 17.1 years, p = 0.25) and sex (p = 0.85). No surgical site infection requiring operative revision was reported for either group. No significant differences for blood loss per level (obese vs nonobese: 9.7 ± 16.8 ml vs 8.0 ± 13.3 ml, p = 0.49) or duration of surgery per level (obese vs nonobese: 91.2 ± 57.7 minutes vs 76.8 ± 39.2 minutes, p = 0.44) were reported between groups. Obese patients showed significantly faster improvement regarding ODI (-3.0 ± 9.8 vs 0.7 ± 11.3, p = 0.01) and leg pain (-4.4 ± 3.2 vs -2.9 ± 3.7, p = 0.03) 7 days postsurgery. This effect was no longer significant 90 days postsurgery for either ODI (obese vs nonobese: -11.4 ± 11.4 vs -9.1 ± 9.6, p = 0.24) or leg pain (obese vs nonobese: -4.3 ± 3.9 vs -3.5 ± 3.8, p = 0.28). CONCLUSIONS: The results highlight the effectiveness and safety of lumbar FESS in obese patients. Unlike with open spine surgery, obese patients did not experience significant increases in surgery time or postoperative complications. Interestingly, obese patients demonstrated faster early recovery, as indicated by significantly greater improvements in ODI and leg pain at 7 days after surgery. However, there was no difference in improvement between the groups at 90 days after surgery.

Increased stability due to symmetric cement volume in augmented pedicle screws? A biomechanical study.

Pedicle screw instrumentation has become "state of the art" in surgical treatment of many spinal disorders. Loosening of pedicle screws due to poor bone mineral density is a frequent complication in osteoporotic patients. As prevalence of osteoporosis and spinal disorders are increasing with an aging demographic, optimizing the biomechanical properties of pedicle screw constructions and therefore outcome after spinal surgery in osteoporotic patients is a key factor in future surgical therapy. Therefore, this biomechanical study investigated the stability of polymethylmethacrylate (PMMA)-augmented pedicle screw-rod constructions under a deviating distribution of PMMA applied to the instrumentation in osteoporotic human cadaveric vertebrae. We showed that PMMA-augmented pedicle screw-rod constructions tend to be more stable than those with non-augmented pedicle screws. Further, there appears to be a larger risk of screw loosening in unilateral augmented pedicle screws than in non-augmented, therefore a highly asymmetrically distributed PMMA should be avoided.

Detection of Cutibacterium (Propionibacterium) acnes in orthopaedic surgery: serious problem or contamination?

PURPOSE: Bone and joint infections are an important and increasing problem. Whether intraoperatively detected bacteria should be considered relevant or not is often difficult to assess. This retrospective cohort study analyzes the relevance of C. acnes cultured from deep intraoperative specimens. METHODS: All deep tissue samples collected intraoperatively between 2015 and 2020 from a quartiary care provider were evaluated for detection of C. acnes and its therapeutical consequences. Infection rates were determined according to a standardized definition and protocol and analyzed in dependence of patient's demographic data (age and gender), operative parameters (type of surgery, body region/location of surgery, and impression of the surgeon), and initiated therapy. RESULTS: In 270 cases of more than 8500 samples, C. acnes was detected. In 30%, the detection was considered an infection. The number of samples taken and tested positive for C. acnes correlated significantly with its classification as a cause of infection. If more than one sample of the patient was positive, the detection was significantly more likely to be treated as infection (p < 0.001). In 76% of cases, a consultation to the infectious diseases (ID) department took place regarding the classification of the pathogen detection and the therapy to be carried out. Almost all of the tested isolates demonstrated the wild-type susceptibility for penicillin and clindamycin. CONCLUSION: Intraoperative detection of skin-colonizing bacteria such as C. acnes is not always synonymous with infection. In particular, if other examination results contradict an infection (pathological sample without evidence of an infectious event, detection of malignant cells, etc.), the situation must be considered in a very differentiated manner. Interdisciplinary boards, for example, are suitable for this purpose. Care should be taken to obtain a sufficiently large number of tissue samples for microbiological examination to be able to better classify the result.

Impact of the blood group on postoperative CRP and leukocyte levels after primary total hip and knee arthroplasty.

BACKGROUND: C-reactive protein (CRP)- and leukocyte levels are common parameters to evaluate the inflammatory response after orthopaedic surgery and rule out infectious complications. Nevertheless, both parameters are vulnerable to disturbing biases and therefore leave room for interpretation. OBJECTIVE: Since blood groups are repeatedly discussed to influence inflammatory response, our aim was to observe their impact on CRP and leukocyte levels after total hip and knee arthroplasty (THA/TKA). METHODS: Short term postoperative CRP and leukocyte levels of 987 patients, who received either primary TKH (n= 479) or THA (n= 508), were retrospectively correlated with their blood group. ABO, Rhesus and a combination of both blood groups were differentiated. RESULTS: CRP levels after TKA were significantly higher in blood type AB than in type A and O on day 2-4 and also than in type A on day 6-8. Leukocyte levels after THA were significantly higher in blood group type O than in type A on day 6-8 while still remaining in an apathological range. We observed no significant differences between Rhesus types and Rhesus types and CRP or leukocyte levels. CONCLUSION: We observed significantly increased CRP levels after TKA in patients with blood group AB. Since the elevated CRP levels do not account for early periprosthetic infection, surgeons should include this variation in their postoperative evaluation.

A correction factor is needed for the intraoperative measurement of cup inclination in total hip arthroplasty.

BACKGROUND: The cup inclination in total hip arthroplasty is key to minimising complications. Stereometric effects (parallax) in two-dimensional projections can alter angle measurements. Even for different approaches, fluoroscopy causes different results in the measurement of inclination. A previous study has introduced a corrective factor for intraoperative radiographic cup inclination measurements compared to the postoperative standing radiographs. OBJECTIVE: The aim of this study was to find out whether, first, the correction factor is reproducible and second, whether the correction factor is independent of the surgical approach and C-arm model used. METHODS: A series of 377 cases of primary total hip arthroplasty was reviewed. We compared the cup inclination angle in the intraoperative and postoperative radiographic images. Based on this, it was possible to specify a standard of correction factor in defined ranges. RESULTS: The mean cup inclination in intraoperative images was 37.47∘ and the mean angle in postoperative images was 41.42, resulting in a mean difference of 3.95∘ with a strong correlation (r= 0.706). CONCLUSION: An added correction factor of 4∘ should be respected in intraoperative inclination measurements to adapt for parallax. An increased correction factor of 6∘ in particularly low-positioned cups (< 31∘) and a decreased correction factor of 2∘ in particularly steeply positioned cups (> 43∘) is recommended.

Surgery for Vertebral Osteomyelitis Lowers 1-Year Mortality and Failure Rates Compared with Nonsurgical Treatment: A Propensity-Matched Analysis.

BACKGROUND: The aim of this study was to determine differences between patients who underwent surgical treatment and those who underwent nonsurgical treatment of vertebral osteomyelitis (VO) and to identify potential factors influencing treatment failure (death and/or recurrence within 1 year). METHODS: We performed a retrospective analysis of clinical data prospectively collected from patients treated for VO between 2008 and 2020. The decision between surgical and nonsurgical treatment was made for each patient based on defined criteria. A 1:1 propensity score matching was performed to exclude confounders between the 2 treatments. Univariate and multivariable analyses were performed to identify potential risk factors for death and/or recurrence within the first year after VO diagnosis. RESULTS: Forty-two patients (11.8%) were treated nonsurgically and 313 patients (88.2%) underwent surgery. A higher percentage of the surgically treated patients than the nonsurgically treated patients had an American Society of Anesthesiologists score of >2 (69.0% versus 47.5%; p = 0.007), and the thoracic spine was affected more often in the surgical group (30.4% versus 11.9%; p = 0.013). Endocarditis was detected significantly more often in the nonsurgically treated patients (14.3% versus 4.2%; p = 0.018). The recurrence rate was 3 times higher in the nonsurgically treated patients (16.7% versus 5.4%; p = 0.017), but this difference was no longer detectable after propensity matching. After matching, the nonsurgically treated patients showed an almost 7-fold higher 1-year mortality rate (25.0% versus 3.7%; p = 0.018) and an almost 3-fold higher rate of treatment failure (42.9% versus 14.8%; p = 0.022). Multivariable analysis revealed nonsurgical treatment and bacteremia to be independent risk factors for treatment failure. CONCLUSIONS: In our matched cohort of patients with VO, surgical intervention resulted in a significantly lower rate of treatment failure (death and/or recurrence within 1 year) compared with nonsurgical intervention. Furthermore, nonsurgical treatment was an independent risk factor for treatment failure. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.