Sonication in Patients With Spinal Cord Stimulation: A New Approach for Infection Diagnostics.

INTRODUCTION: Spinal cord stimulation (SCS) offers improvement in pain and function for several chronic pain conditions. There are concerns regarding bacterial colonization of the temporary lead extensions and subsequent infection risk in a two-session implantation procedure. Although there is no standardized evaluation of SCS lead contamination, this study evaluates the infection rate and microbial colonization of SCS lead extensions with sonication, a method that is established in implant-related infection diagnostics. MATERIALS AND METHODS: This prospective observational study comprised 32 patients with a two-stage SCS implantation procedure. Microbial colonization of the lead extensions was assessed with sonication. The presence of organisms in the subcutaneous tissue was evaluated separately. Surgical-site infections were recorded. Patient demographics and risk factors including diabetes, tobacco use, obesity, trial length, and infection parameters in serum were recorded and analyzed. RESULTS: The mean age of the patients was 55 years. On average, the trial length was 13 days. In seven cases (21.9%), a microbial lead colonization was found with sonication. In contrast, there was one positive culture (3.1%) from the subcutaneous tissue samples. The C-reactive protein and leukocyte count remained at the preoperative level. One early surgical-site infection (3.1%) occurred. No other late infections occurred six months after surgery. CONCLUSIONS: There is a discrepancy between the presence of microbial colonization and the occurrence of clinically relevant infections. Although the rate of microbial colonization of the lead extensions is high (21.9%), the surgical-site infection rate remained low (3.1%). Therefore, we can conclude that the two-session procedure is a safe approach that is not associated with a higher incidence of infection. Although the sonication method cannot be used as the sole tool for detecting infections in patients with SCS, it can provide additional value in microbial diagnostics in combination with clinical and laboratory parameters and conventional microbiological methods.

APP-guided assessment of acetabular defects in hip revision arthroplasty: a structured approach to a complex situation.

INTRODUCTION: Acetabular defect recognition and classification remains a challenging field of practice for orthopedic surgeons. Recently, the Acetabular Defect Classification (ADC) has been introduced to provide a reliable, reproducible and intuitive classification system. In order to improve ease of use and efficiency of the ADC, a browser-based application has been created. We hypothesized that the ADC application can improve rating performance of non-specialists (medical students) to achieve good inter- and intra-rater agreement and will compare favorable to the results of specialists (experienced surgeons) without the help of the application. MATERIALS AND METHODS: The ADC is based on the integrity of the acetabular rim and the supporting structures. It consists of four main types of defects ascending in severity. These defects are further subdivided in A-C, narrowing down defect location. 80 randomized radiographs were graded according to ADC by three non-specialists (medical students) with help of the ADC application and by three specialists (orthopedic surgeons) without help of the application to evaluate the difference in inter-rater agreement between groups. To account for intra-rater agreement, the rating process was repeated after a reasonable wash-out period. RESULTS: Inter-rater and intra-rater agreement within the non-specialist group rated lower when compared to the specialist group while still falling into the good agreement range. The student group presented with k values of 0.61 for inter-rater agreement and 0.68 for intra-rater agreement, while the surgeon group displayed k values of 0.72 for inter-rater agreement and 0.83 for intra-rater agreement. CONCLUSION: The app-guided assessment of acetabular defects offers a promising innovative approach to simplify complex situations. It makes the challenging field of acetabular revision arthroplasty more approachable especially for less experienced surgeons and offers insight and guidance in the planning stage as well as intra-operative setting.

Femoral defects in revision hip arthroplasty: a therapy-oriented classification.

INTRODUCTION: The complex field of femoral defects in revision hip arthroplasty displays a lack of standardized, intuitive pre- and intraoperative assessment. To address this issue, the femoral defect classification (FDC) is introduced to offer a reliable, reproducible and an intuitive classification system with a clear therapeutic guideline. MATERIALS AND METHODS: The FDC is based on the integrity of the main femoral segments which determine function and structural support. It focuses on the femoral neck, the metaphysis consisting of the greater and lesser trochanter, and the femoral diaphysis. The four main categories determine the location of the defect while subcategories a, b and c are being used to classify the extent of damage in each location. In total, 218 preoperative radiographs were retrospectively graded according to FDC and compared to intraoperatively encountered bone defects. To account for inter-rater and intra-rater agreement, 5 different observers evaluated 80 randomized cases at different points in time. RESULTS: A Cohens kappa of 0.832 ± 0.028 could be evaluated, accounting for excellent agreement between preoperative radiographs and intraoperative findings. To account for inter-rater reliability, 80 patients have been evaluated by 5 different observers. Testing for inter-rater reliability, a Fleiss Kappa of 0.688 could be evaluated falling into the good agreement range. When testing for intra-rater reliability, Cohens Kappa of each of the 5 raters has been analyzed and the mean was evaluated at 0.856 accounting for excellent agreement. CONCLUSION: The FDC is a reliable and reproducible classification system. It combines intuitive use and structured design and allows for consistent preoperative planning and intraoperative guidance. A therapeutic algorithm has been created according to current literature and expert opinion. Due to the combination of the FDC with the recently introduced Acetabular Defect Classification (ADC) a structured approach to the entire field of hip revision arthroplasty is now available.

Cervical spine injuries requiring surgery in a Level I trauma centre in a major German city.

BACKGROUND: Cervical spine injuries (CSI) are rare in trauma patients, at about 9.2-16.5/100,000 inhabitants in Scandinavia and Canada, and the annual incidence of CSI surgeries in Norway is around 3.0/100,000 inhabitants. However, despite their rarity, the incidence of CSI has increased, thereby assuming an increasing need for surgery. Outside of Scandinavia, no data about the incidence of CSI and subsequent surgeries exist. Therefore, this study aimed to analyse CSI epidemiology and surgery in a German city with a Level I trauma centre both to understand the injury and improve needs-based planning. METHODS: This retrospective, monocentre study included all patients who presented with CSI from 2012-2017 at a university hospital with a Level I trauma centre in a major German city and had permanent residency within the city. Based on the assumption that the patients represented all CSI injuries in the city, as they were treated at the only available Level I trauma centre, the annual incidence of surgeries and neurologic deficits due to CSI were calculated. RESULTS: A total of 465 patients with 609 CSI were identified. Of these patients, 61 both received surgery and resided in the city (mean age, 68.1 ± 18.3 years; 26 female, 35 male). The incidence of CSI surgeries was calculated as 3.24/100,000 person years (1.75/100,000 in the upper and 1.54/100,000 in the subaxial cervical spine). Neurologic deficits occurred in 0.64/100,000 person years. The incidence of both surgeries and neurologic deficits showed no significant changes over the 6-year study period. CONCLUSIONS: Compared to Scandinavia, an increasing annual incidence for CSI surgeries and neurologic deficits were found. For long-term demand planning with adaptability to demographic changes, cross-regional studies including long-term follow-up are necessary.

Is Prematurity a Protective Factor Against Developmental Dysplasia of the Hip? A Retrospective Analysis of 660 Newborns.

PURPOSE: In Middle Europe developmental dysplasia of the hip (DDH) has an incidence of up to 5.9 %. The rate of congenital hip dislocation as the worst complication of a growth disorder of the hip is between 1.5 % and 2.5 %. Among known risk factors of DDH are breech position, multiples, foot deformities and family history. The aim of this retrospective study was to investigate prematurity as a risk factor for developmental dysplasia of the hip (DDH). MATERIALS AND METHODS: The hips of 283 infants who were born before the 38th week of gestation or earlier, and those of 377 infants who were born after the 37th week of gestation, none of whom had other risk factors for DDH, were compared using the ultrasound technique according to Graf et al., within the first week after birth. Both hips of all infants were included in the study. RESULTS: Surprisingly, the difference in alpha angles between the two groups was statistically extremely significant, favoring the preterm infants. Moreover, we found a physiological curve of alpha angle development with a peak after the 31st week of gestation. The incidence of pathological dysplasia was not significantly different in the two groups. CONCLUSION: Our results suggest that prematurity is not a predisposing factor for DDH, but rather is protective for hip development.

Litigations in orthopedics and trauma surgery: reasons, dynamics, and profiles.

BACKGROUND: In recent literature, the increasing number of medical litigations, both in terms of the number of cases being filed and the substantive costs associated with lawsuits, has been described. This study aims to provide an overview of the profile of litigation for orthopedic and trauma surgery to describe the differences and the development of the number of cases over time. PATIENTS AND MATERIALS: A retrospective review of all litigations between 2000 and 2017 was conducted using the institutional legal database. The causes of litigation were documented and classified into seven major categories. In addition to plaintiff characteristics, the litigation outcomes and the differences between emergency and elective surgery were analyzed. RESULTS: A total of 230 cases were evaluated. The mean age of the plaintiffs was 44.6 ± 20.1 years, and 56.8% were female. The main reasons for litigation were claimed inappropriate management (46.1%), misdiagnosis (22.6), and poor nursing care (8.3%). Significantly more litigations were filed against surgeons of the orthopedic subspecialty compared with trauma surgeons (78%; p ≤ 0.0001). There were significantly fewer litigations per 1000 cases filed overall in 2009-2017 (65% less; p = 0.003) than in 2000-2008. CONCLUSION: Our results could not confirm the often-stated trend of having more litigations against orthopedic and trauma surgeons. Although the absolute numbers increased, the number of litigations per 1000 patients treated declined. Patients who underwent elective surgery were more likely to file complaints than emergency patients.

Cervical spine injuries in spinal ankylosing disorders: results of single-stage posterior stabilization without posterolateral fusion.

Patients with long-segment cervical spinal fusion resulting from spinal ankylosing disorders (SADs) are at high risk for highly unstable cervical spine fractures necessitating surgery as the treatment of choice; however, without an existing gold standard. Specifically, patients without concomitant myelo- pathy, representing a rare entity, may benefit from a minimized surgical approach of a single-stage posterior stabilization without bone grafting for posterolateral fusion. This retrospective monocenter study in a Level I trauma center included all patients treated with navigated posterior stabilization without posterolateral bone grafting between January 2013 and January 2019 for cervical spine fractures in preexisting SADs without myelopathy. The outcomes were analyzed based on complication rates, revision frequency, neurologic deficits, and fusion times and rates. Fusion was evaluated by X-ray and computed tomography. 14 patients (11 male, 3 female) with a mean age of 72.7 ± 17.6 years were included. Five fractures were at the upper and nine at the subaxial cervical spine (predominantly C5-7). There was one surgery-specific complication of postoperative paresthesia. There was no infection, implant loosening, or dislocation, and no revision surgery necessary. All fractures healed after a median time of 4 months and 12 months being the latest time of fusion in one patient. Single-stage posterior stabilization without posterolateral fusion is an alternative for patients with SADs and cervical spine fractures without myelopathy. They can benefit from a minimization of surgical trauma while having equal times of fusion and no increased rate of complications.

Acetabular defects in revision hip arthroplasty: a therapy-oriented classification.

INTRODUCTION: The treatment of severe acetabular bone loss remains a difficult challenge. No classification system is available that combines intuitive use, structured design and offers a therapeutic recommendation according to the current literature and modern state of the art treatment options. The goal of this study is to introduce an intuitive, reproducible and reliable guideline for the evaluation and treatment of acetabular defects. METHODS: The proposed Acetabular Defect Classification (ADC) is based on the integrity of the acetabular rim and supporting structures. It consists of 4 main types of defects ascending in severity and subdivisions narrowing down-defect location. Type 1 presents an intact acetabular rim, type 2 includes a noncontained defect of the acetabular rim ≤ 10 mm, in type 3 the rim defect exceeds 10 mm and type 4 includes different kinds of pelvic discontinuity. A collective of 207 preoperative radiographs were graded according to ADC and correlated with intraoperative findings. Additionally, a randomized sample of 80 patients was graded according to ADC by 5 observers to account for inter- and intra-rater reliability. RESULTS: We evaluated the agreement of preoperative, radiographic grading and intraoperative findings presenting with a k value of 0.74. Interobserver agreement presented with a k value of 0.62 and intraobserver at a k value of 0.78. CONCLUSION: The ADC offers an intuitive, reliable and reproducible classification system. It guides the surgeon pre- and intraoperatively through a complex field of practice.

Outcome evaluation of new calcium titanate schanz-screws for external fixators. First clinical results and cadaver studies.

OBJECTIVE: External fixators are important for correcting length discrepancies and axis deformities in pediatric or trauma orthopedic surgery. Pin loosening is a common pitfall during therapy that can lead to pain, infection, and necessary revisions. This study aims to present clinical data using calcium titanate (CaTiO3) Schanz screws and to measure the fixation strength. PATIENTS AND METHODS: 22 titanate screws were used for external fixators in 4 pediatric patients. Therapy was initiated to lengthen or correct axial deformities after congenital abnormalities. The maximum tightening torque was measured during implantation, and the loosening torque was measured during explantation. In addition, screws of the same type were used in a cadaver study and compared with stainless steel and hydroxyapatite-coated screws. 12 screws of each type were inserted in four tibias, and the loosening and tightening torque was documented. RESULTS: The fixation index in the in vivo measurement showed a significant increase between screw insertion and extraction in three of the four patients. The pins were in situ for 91 to 150 days, and the torque increased significantly (P = 0.0004) from insertion to extraction. The cadaveric study showed lower extraction torques than insertion torques, as expected in this setting. The calculated fixation index was significantly higher in the CaTiO3 group than in the other groups (P = 0.0208 vs. HA and P < 0.0001 vs. steel) and in the HA group vs. plain steel group (P = 0.0448). CONCLUSION: The calcium titanate screws showed favorable fixation strength compared to HA and stainless steel screws and should be considered in long-term therapy of external fixation.

Comparison of two-stage revision arthroplasty and intramedullary arthrodesis in patients with failed infected knee arthroplasty.

BACKGROUND: Failed total knee arthroplasty (TKA) with significant bone loss and compromised soft-tissues is challenging and the final results are often inferior to patient's expectation. The objective of this study was to present a comparison of outcomes in patients with failed infected TKA treated with two-stage revision TKA or knee arthrodesis and to assess clinical and functional results, implant survival and infection recurrence. The hypothesis was that an arthrodesis may result in beneficial effects on patients' outcome. METHODS: Clinical data of 81 patients with periprosthetic joint infection (PJI) of the knee joint were collected and analyzed retrospectively. Between 2008 and 2014, a total of 36 patients had been treated within a two-stage exchange procedure and reimplantation of a modular intramedullary arthodesis nail and 45 patients with revision TKA. Patients were treated according to the same structured treatment algorithm. Clinical and functional evaluation was performed using the Oxford knee score (OKS) and the visual analogue scale (VAS). RESULTS: The mean follow-up was 32.9 ± 14.0 months. The rate of definitely free of infection at last follow-up in the arthrodesis group was 32 of 36 (88.9%) and 36 of 45 (80.0%) in the revision TKA group (p = 0.272). Mean VAS for pain in the arthrodesis group was 3.1 ± 1.4 compared to 3.2 ± 1.6 in the revision TKA group (p = 0.636). The OKS in the arthrodesis group was 38.7 ± 8.9 and 36.5 ± 8.9 (p = 0.246) in patients with revision TKA. Rate of revisions in the revision-TKA group was 2.8 ± 3.7 compared to 1.2 ± 2.4 in the arthrodesis group (p = 0.021). CONCLUSION: Treatment of PJI needs a distinct therapy with possible fallback strategies in case of failure. A knee arthrodesis is a limb salvage procedure that showed no significant benefits on the considered outcome factors compared to revision TKA but is associated with significantly lower revision rate. After exhausted treatment modalities, a knee arthrodesis should be considered as an option in selected patients. LEVEL OF EVIDENCE: Level III, retrospective cohort study.