Comprehensive Analysis of Scientific Output in Hip and Knee Arthroscopy.

PURPOSE OF THE STUDY A global bibliometric comparison of the level of scientific interest and output in the two research areas hip and knee arthroscopy (H-ASC and K-ASC) was carried out. In addition, the different degrees of publication activity in the countries and institutes performing this research were investigated. MATERIAL AND METHODS Publications from 1945-2020 listed in the Web of Science Core Collection were included in the study. Using the web application Science Performance Evaluation (SciPE), quantitative and qualitative aspects were evaluated. Subsequently, the date of publication, author information, and other metadata were analysed. RESULTS Since 1945, 3,924 studies have been published on K-ASC and 2,163 on H-ASC. The majority of the publications which have appeared since 2016 dealt with the topic of H-ASC (H-ASC: 241.2 publications/year; K-ASC: 217.4 publications/year). The USA published the most on both topics (H-ASC: 1,123 publications; K-ASC: 1,078 publications). More countries and institutes participated in K-ASC (3,008 institutes, 82 countries) than in H-ASC (103 institutes, 57 countries). The ten institutes with the most publications accounted for 36.71% and 12.34% of all publications on H-ASC and K-ASC, respectively. H-ASC received 78.12% of its funding from private sponsors while K-ASC was supported mainly by governmental/nonprofit sponsors (70.92%). CONCLUSIONS This study provides the first scientific comparison between H-ASC and K-ASC. Measured by qualitative and quantitative aspects, K-ASC was the most flourishing research area overall. In the last ten to five years, interest has shifted towards HASC with an increasing number of publications and a higher rate of citations. Key words: knee arthroscopy, hip arthroscopy, bibliometric comparison.

[Footballer's hip]. / Die Fußballerhüfte.

Although complaints and injuries in the knee and ankle joints are very prevalent in football, the hip has so far been given very little attention. Complaints in this area are often attributed to pathological changes in the inguinal region. However, intraarticular differential diagnoses are often not taken into consideration. This article gives an overview of possible hip pathology in footballers, as well as its diagnosis and treatment.

[Apps in clinical use in orthopedics and trauma surgery : The status quo in Germany]. / Klinischer Einsatz mobiler Applikationen in der Orthopädie und Unfallchirurgie in Deutschland : Eine Bestandsaufnahme.

In the course of digitalization the smartphone is penetrating more and more areas of life giving the user mobile and almost ubiquitous access to the internet and other web applications. The advantages of mHealth are an integral part in some areas of patient care but in contrast to other disciplines, routine integration of mobile devices into orthopedics and trauma surgery is still in its infancy. A survey among German orthopedists and trauma surgeons revealed which kind of apps have become established in everyday clinical practice to date. Apps published by representative institutions such as the AO Foundation demonstrated the highest usage rates. In summary, the number of regularly used apps is low; however, the causes of this lack of acceptance have not yet been conclusively clarified. The authors of this study proclaim a significant increase in the use of mHealth and mobile devices in daily clinical practice in the future.

[Kinematic examination of the musculoskeletal system : Use of methods of image and image sequence analyses as well as shape and motion models]. / Kinematische Untersuchungen des muskuloskelettalen Systems : Nutzung von Bild- und Bildfolgenanalysen sowie Form- und Bewegungsmodellen.

Image-based preoperative planning has become a routine component in surgery on the musculoskeletal system. In joint arthroplasty it is obligatory. Surgeons are increasingly considering new approaches with additional computer-based kinematic examinations that also generate dynamic image analyses. This article describes several of these new examination techniques and discusses their clinical relevance.

[Characteristics of elective hip replacement in the elderly]. / Besonderheiten beim elektiven Hüftgelenkersatz des älteren Menschen.

Due to demographic changes the number of elderly patients undergoing hip replacement surgery is increasing. In order to ensure safe treatment of elderly patients, age-specific medical factors must be taken into consideration. This article presents an overview of these factors. Furthermore, we evaluated our own patients treated between 2010 and 2015 regarding age-related treatment strategies and complication rates. Out of 3166 patients a total of 439 were over 80 years old (average age 84 years). It can be concluded from the scientific literature and from own data that elective hip replacement surgery in elderly patients is a technically safe procedure; however, the risk profile of each patient must be thoroughly analyzed so that in the event of even minor signs of potential complications countermeasures can be taken in good time.

Hip imaging of avascular necrosis at 7 Tesla compared with 3 Tesla.

OBJECTIVES: To compare ultra-high field, high-resolution bilateral magnetic resonance imaging (MRI) of the hips at 7 Tesla (T) with 3 T MRI in patients with avascular necrosis (AVN) of the femoral head by subjective image evaluations, contrast measurements, and evaluation of the appearance of imaging abnormalities. MATERIALS AND METHODS: Thirteen subjects with avascular necrosis treated using advanced core decompression underwent MRI at both 7 T and 3 T. Sequence parameters as well as resolution were kept identical for both field strengths. All MR images (MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR) were evaluated by two radiologists with regard to subjective image quality, soft tissue contrasts, B1 homogeneity (four-point scale, higher values indicating better image quality) and depiction of imaging abnormalities of the femoral heads (three-point scale, higher values indicating the superiority of 7 T). Contrast ratios of soft tissues were calculated and compared with subjective data. RESULTS: 7-T imaging of the femoral joints, as well as 3-T imaging, achieved "good" to "very good" quality in all sequences. 7 T showed significantly higher soft tissue contrasts for T2w and MEDIC compared with 3 T (cartilage/fluid: 2.9 vs 2.2 and 3.6 vs 2.6), better detailed resolution for cartilage defects (PDw, T2w, T1w, MEDIC, DESS > 2.5) and better visibility of joint effusions (MEDIC 2.6; PDw/T2w 2.4; DESS 2.2). Image homogeneity compared with 3 T (3.9-4.0 for all sequences) was degraded, especially in TSE sequences at 7 T through signal variations (7 T: 2.1-2.9); to a lesser extent also GRE sequences (7 T: 2.9-3.5). Imaging findings related to untreated or treated AVN were better delineated at 3 T (≤1.8), while joint effusions (2.2-2.6) and cartilage defects (2.5-3.0) were better visualized at 7 T. STIR performed much more poorly at 7 T, generating large contrast variations (1.5). CONCLUSIONS: 7-T hip MRI showed comparable results in hip joint imaging compared with 3 T with slight advantages in contrast detail (cartilage defects) and fluid detection at 7 T when accepting image degradation medially.

Bilateral hip imaging at 7 Tesla using a multi-channel transmit technology: initial results presenting anatomical detail in healthy volunteers and pathological changes in patients with avascular necrosis of the femoral head.

OBJECTIVE: To evaluate 7-T MRI of both hips using a multi-channel transmit technology to compensate for inherent B1 inhomogeneities in volunteers and patients with avascular necrosis of the femoral head. MATERIALS AND METHODS: A self-built, eight-channel transmit-receive coil was utilized for B1 modification at 7 T. Two shim modes (individual shim vs. CP2+ mode) were initially compared and the best shim result was used for all further imaging. Robustness of sequences against B1 inhomogeneities, appearance of anatomic and pathologic changes of the femoral heads of MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR sequences at 7 T were evaluated in 12 subjects on a four-point scale (1-4): four male volunteers and eight patients (seven males, one female) suffering from avascular necrosis treated by advanced core decompression. RESULTS: Successful MRI of both femoral heads was achieved in all 12 subjects. CP2+ mode proved superior in ten of 12 cases. DESS proved most robust against B1 inhomogeneity. Anatomical details (labrum, articular cartilage) were best depicted in PDw, MEDIC, and DESS, while for depiction of pathological changes PDw, DESS (0.76 mm(3)) and T1w were superior. CONCLUSIONS: Our initial results of ultra-high-field hip joint imaging demonstrate high-resolution, high-contrast images with a good depiction of anatomic and pathologic changes. However, shifting areas of signal dropout from the femoral heads to the center of the pelvis makes these areas not assessable. For clinical workflow CP2+ mode is most practical. Seven-Tesla MRI of the hip joints may become a valuable complement to clinical field strengths.

Arthroscopic synovectomy and radiosynoviorthesis: a treatment option for recurrent arthritis symptoms in patients with pachydermoperiostosis.

Pachydermoperiostosis as the primary form of hypertrophic osteoarthropathy is a rare hereditary disorder with a number of characteristic findings, e.g. periosteal hypertrophy, digital clubbing and pachydermia. Further typical symptoms include arthritic manifestations in all major joints. Literature review showed that therapeutical approaches usually focus on medical therapy alleviating chronic polyarthritis by controlling inflammation. In the case presented in this report anti-inflammatory therapy appeared to have been insufficient since knee arthritis persisted. Arthroscopic synovectomy and radiosynoviorthesis were performed consecutively. Postoperative and follow-up examinations indicate that this combined therapy reduces pain, increases range of motion and improves overall mobility, and is thus of lasting benefit to the patient.

The influence of chronic kidney disease on the duration of hospitalisation and transfusion rate after elective hip and knee arthroplasty.

PURPOSE: Elective hip or knee replacement is an optimal, standardised orthopaedic surgical procedure. The influence of chronic kidney disease, defined as an estimated glomerular filtration rate (eGFR) of 15-45 ml/min/1.73 m2 body surface area (BSA) (KDIGO stage G3a-G4), on the duration of hospitalisation, perioperative decrease in haemoglobin (Hb) levels, and transfusion rates after orthopaedic procedures has not been fully clarified. Our study, therefore, aimed to evaluate the impact of chronic kidney disease on the previously mentioned variables. METHODS: We conducted a retrospective multicentre analysis involving two orthopaedic centres. Patients who underwent elective total hip and knee replacement between 2010 and 2015 were included. We used descriptive methods and multivariate linear and binary regression analyses for our statistical evaluations. RESULTS: We evaluated 3301 datasets (1120 men [33.9%], 2181 women [66.1%], 2043 [61.9%], and 1258 [38.1%]) elective total hip and knee replacements, respectively. The following variables were identified as risk factors for a prolonged hospital stay: patient age, admission Hb and potassium levels, perioperative Hb level decrease, year of surgery, blood transfusion, and a preoperative eGFR of 15-45 ml/min/m2 BSA. Patients with an eGFR of > 45 ml/min/m2 BSA were discharged within 11.7 ± 3.0 days, while patients with an eGFR of 15-45 ml/min/1.73 m2 BSA remained inpatient for 13.5 ± 5.0 days (p < 0.001). Identified risk factors for postoperative blood transfusions included age, initial Hb level, perioperative Hb decrease, prosthetic hip replacement, and the presence of allergic diathesis. Blood transfusions were performed in 7.5% of patients with an eGFR of > 45 ml/min/m2 BSA compared to 24.1% of patients with an eGFR of 15-45 ml/min/1.73 m2 BSA (p < 0.001). An eGFR level of 15-45 ml/min/m2 BSA was identified as a risk factor for a postoperative decrease in Hb levels. CONCLUSION: Chronic kidney disease, defined as an eGFR level of 15-45 ml/min/1.73 m2 BSA, was a risk factor for a prolonged hospital stay after elective hip and knee arthroplasty. Further studies are necessary to better define the effect of reduced kidney function on relevant clinical and socioeconomic outcome parameters.

Effect of the stiffness of bone substitutes on the biomechanical behaviour of femur for core decompression.

Core decompression is the most common procedure for treatment of the early stages of osteonecrosis of the femoral head. The purpose of this study was to compare the biomechanical performance of four different bone graft substitutes combined with core decompression. Subject-specific finite element models generated from computed tomography (CT) scan data were used for a comprehensive analysis. Two different contact conditions were simulated representing states of osseointegration at the interface. Our results showed that the use of a low-stiffness bone substitute did not increase the risk of femoral fracture in the early postoperative phase, but resulted in less micromotion and interfacial stresses than high-stiffness bone substitutes.

Functional interest of an articulating spacer in two-stage infected total knee arthroplasty revision.

INTRODUCTION: Deep periprosthetic infection is one of the most serious complications after total knee replacement. The two-stage procedure with implantation of a temporary cement spacer and later re-implantation of a revision total knee prosthesis is an accepted procedural standard. The use of articulating spacers has been proposed to enhance ease of revision and functional results. PATIENTS AND METHODS: Twenty-three patients treated with an articulating spacer were retrospectively studied. All patients had undergone a two-stage surgery. The infected prosthesis was explanted and the femoral component was sterilized and re-implanted. On the tibial side a block of gentamicin-loaded bone cement was produced intraoperatively using specially manufactured templates. Eighteen total knee arthroplasty revisions and 5 arthrodesis were finally performed. RESULTS: A total of three (13%) re-infections occurred 5-20 months after revision total knee arthroplasty in a mean follow-up period of 47 months. Prior to re-implantation, flexion with the articulating spacer ranged between 15 and 100° (mean 68±28°). The average postoperative flexion after re-implantation of total knee replacement was 105±11°. CONCLUSION: The articulating spacer used in this study appears to be as effective as the standard procedures in terms of re-infection risk rate and postoperative range of motion recovery. LEVEL OF EVIDENCE: Level IV.

Experimental and computational studies on the femoral fracture risk for advanced core decompression.

BACKGROUND: Two questions are often addressed by orthopedists relating to core decompression procedure: 1) Is the core decompression procedure associated with a considerable lack of structural support of the bone? and 2) Is there an optimal region for the surgical entrance point for which the fracture risk would be lowest? As bioresorbable bone substitutes become more and more common and core decompression has been described in combination with them, the current study takes this into account. METHODS: Finite element model of a femur treated by core decompression with bone substitute was simulated and analyzed. In-vitro compression testing of femora was used to confirm finite element results. FINDINGS: The results showed that for core decompression with standard drilling in combination with artificial bone substitute refilling, daily activities (normal walking and walking downstairs) are not risky for femoral fracture. The femoral fracture risk increased successively when the entrance point is located further distal. The critical value of the deviation of the entrance point to a more distal part is about 20mm. INTERPRETATION: The study findings demonstrate that optimal entrance point should locate on the proximal subtrochanteric region in order to reduce the subtrochanteric fracture risk. Furthermore the consistent results of finite element and in-vitro testing imply that the simulations are sufficient.

The distribution of nociceptive innervation in the painful hip: a histological investigation.

Our understanding of the origin of hip pain in degenerative disorders of the hip, including primary osteoarthritis, avascular necrosis and femoroacetabular impingement (FAI), is limited. We undertook a histological investigation of the nociceptive innervation of the acetabular labrum, ligamentum teres and capsule of the hip, in order to prove pain- and proprioceptive-associated marker expression. These structures were isolated from 57 patients who had undergone elective hip surgery (44 labral samples, 33 ligamentum teres specimens, 34 capsular samples; in 19 patients all three structures were harvested). A total of 15,000 histological sections were prepared that were investigated immunohistochemically for the presence of protein S-100, 68 kDa neurofilament, neuropeptide Y, nociceptin and substance P. The tissues were evaluated in six representative areas. Within the labrum, pain-associated free nerve ending expression was located predominantly at its base, decreasing in the periphery. In contrast, the distribution within the ligamentum teres showed a high local concentration in the centre. The hip capsule had an almost homogeneous marker expression in all investigated areas. This study showed characteristic distribution profiles of nociceptive and pain-related nerve fibres, which may help in understanding the origin of hip pain.

Measurement of the silver ion concentration in wound fluids after implantation of silver-coated megaprostheses: correlation with the clinical outcome.

BACKGROUND: Tumor patients and patients after traumas are endangered by a reduced immune defense, and a silver coating on their megaprostheses may reduce their risks of infection. The aim of this study was to determine the silver ion concentration directly measured from the periprosthetic tissue and the influence on the clinical outcome. MATERIAL AND METHODS: Silver ions were evaluated in 5 mL wound fluids two days postoperatively and in blood patients 7 and 14 days after surgery using inductively coupled plasma emission spectrometry in 18 patients who underwent total joint replacement with a silver-coated megaendoprosthesis. RESULTS: The concentration of silver ions averaged 0.08 parts per million. Patients who showed an increased silver concentration in the blood postoperatively presented a lower silver concentration in the wound fluids and a delayed decrease in C-reactive protein levels. There were significantly fewer reinfections and shorter hospitalization in comparison with a group that did not receive a silver-coated megaprosthesis. CONCLUSION: An increased concentration of silver in the immediate surroundings of silver-coated prostheses was demonstrated for the first time in cohorts of patients with trauma or tumors. An elevated concentration of silver ions in the direct periprosthetic tissue may have reduced the infection rate.