[Patient safety during endoprosthetic training : Does the training of surgeons in primary hip arthroplasty at certified endoprosthesis centres lead to increased complications?] / Patientensicherheit in der endoprothetischen Weiterbildung : Führt die Weiterbildung von Operateuren in der primären Hüftgelenkendoprothetik in zertifizierten Endoprothesenzentren zu vermehrten Komplikationen?

BACKGROUND: The aim of the study was to investigate whether the perioperative outcome and the operation-specific process variables in patients with total hip arthroplasty (THA) significantly deteriorate when the operation is performed by an inexperienced surgeon assisted by an experienced one in the context of a certified endoprosthesis center. MATERIAL AND METHODS: 1480 patients who received primary THA for primary coxarthrosis between 2013 and 2016 were included. The relevant data were retrospectively documented from the hospital information system, the discharge letter and the EndoCert form. The surgeons were divided according to their qualifications into experienced (senior surgeon, > 50 THA per year) and inexperienced surgeons (junior surgeon, < 50 THA per year). The collected data and measured variables were then compared based on this subdivision. RESULTS: Inexperienced surgeons showed a significant increase in the duration of the operation by 20.7 min (senior 62.6 ± 20.4 min; junior 83.3 ± 19.5 min; p ≤ 0.001), as well as the length of hospital stay by 0.25 days (senior 8.8 ± 0.9 days; junior 9.0 ± 0.9 days; p ≤ 0.001). The frequency of transfusions of red cell concentrates was significantly increased with inexperienced surgeons (senior 0.6 ± 1.1 items; junior 0.9 ± 1.4 items; p ≤ 0.001). In contrast, there was no difference in perioperative complications (p = 0.682) or in perioperative blood loss (senior 1.3 ± 0.5 l; junior 1.3 ± 0.5 l; p = 0.097). However, there was a positive correlation between the duration of the operation and blood loss (senior r = 0.183; junior r = 0.214; each p ≤ 0.01). CONCLUSION: The training of inexperienced surgeons at a certified endoprosthesis center does not lead to a reduction in patient safety or increased complications when inexperienced surgeons are assisted by experienced surgeons. Due to the extended operating time, however, there is an additional burden on the clinics in competition with non-training clinics, which is not mapped in the DRG system.

[Recommendations for unicondylar knee replacement in the course of time : A current inventory]. / Empfehlungen zur unikondylären Schlittenendoprothetik im Wandel der Zeit : Eine aktuelle Bestandsaufnahme.

BACKGROUND: A higher patient satisfaction stands in contrast to higher revision rates of unicondylar knee joint endoprosthetics (UKE) compared to total knee joint endoprosthetics (TKE). Furthermore, old "dogmas" regarding indications and contraindications persist, which is still reflected in the significantly different case numbers. AIM: The aim of this article is to provide an overview of the current literature regarding 1. indication and contraindication (BMI, age, sport, arthrosis of other compartments, ligament status) and 2. the "eternal rival" fixed or mobile bearing for UKE. RESULTS: The choice of the right patient remains essential, even if all the old "dogmas" of contraindications have been relativized or even outdated. Arthroses of the contralateral (in medial UKE correspondingly lateral) compartment and advanced arthroses of the lateral patella facet remain the only persistent contraindications. In contrast, a high BMI, age, chondrocalcinosis, medial patella facet and a defective (but particularly functionally stable) ACL are not contraindications; however, severe obesity is responsible for a significantly higher complication rate and probably a higher rate of loosening. Rather, the experience and thus the number of UKEs of the individual surgeon is decisive for the outcome, to which the discussion about mobile or fixed inlays must also be completely subordinated. CONCLUSION: The indications for UKE can, therefore, be extended with a clear conscience on the basis of literature, and the current 1:10 UKE:TKE ratio in Germany can be shifted significantly.

[Implantation of a tantalum patella during revision surgery]. / Implantation einer Tantalpatella in der Revision.

OBJECTIVE: The reconstruction or restoration of a functioning patella for active extension and flexion by implantation of a tantalum patella. In spite of larger osseous defects of the patella, the goal is to achieve sufficient extensor mechanism function. INDICATIONS: Patients who have such a large bone defect in the area of the patella that implantation of a traditional patella replacement is not possible. In addition, patients with a peri-implant fracture of the patella can be treated with a tantalum patella and additional plate osteosynthesis. CONTRAINDICATIONS: Absence of a cortical basic structure of the patella. Complete loss of the patella or the extensor mechanism. Periprosthetic infection. SURGICAL TECHNIQUE: The patella is completely excised. Subsequently, the back surface of the patella is milled to anchor the tantalum structure as accurately as possible without cement. This is fixed circularly after desired positioning by means of nonresorbable suture. Finally, the polyethylene back surface replacement is cemented onto the back surface of the tantalum structure. POSTOPERATIVE MANAGEMENT: The patients have a limitation of flexion of 0-0-90° at 20 kilogram partial weight bearing for 12 weeks after surgery. RESULTS: A total of 10 patients who received a tantalum patella between 2013 and 2019 were retrospectively included. A tantalum patella was implanted in 9 patients with a large patellar defect. In one case a tantalum patella with additional plate osteosynthesis was implanted to treat a peri-implant fracture of the patella. Loosening of the tantalum patella was observed in 1 patient, while in another patient postoperative arthrofibrosis was observed. In 2 cases a postoperative superficial wound healing disorder was detected. Two patients had a persistent infection with subsequent complete explantation of the prosthesis.

Sodium hypochlorite is more effective than chlorhexidine for eradication of bacterial biofilm of staphylococci and Pseudomonas aeruginosa.

PURPOSE: Periprosthetic infection is a common reason for surgical revision. Given the increasing resistance of bacteria to antibiotics (e.g., VRE, 4-MRGN) local antiseptic treatment is gaining in importance. However, no standard guideline-based treatment recommendation is yet available. The aim of this study was to investigate the effectiveness of sodium hypochlorite and chlorhexidine against bacterial biofilms. Furthermore, the toxicity of both antiseptics towards human chondrocytes was examined. METHODS: Human chondrocytes were isolated, cultivated and treated with sodium hypochlorite and chlorhexidine. The viability of cultures was assessed by determination of cell count, XTT and MTT ELISAs, and fluorescent staining with propidium iodide. Bacterial strains of Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa were added to liquid media and incubated overnight. After determination of bacterial concentrations polyethylene (PE) devices were inoculated with bacteria for 48 h until biofilms formed. The devices were then washed, treated with antiseptics for 2 and 5 min and subsequently spread on agar plates. RESULTS: Sodium hypochlorite is more effective than chlorhexidine in penetrating biofilms of S. aureus, S. epidermidis and P. aeruginosa. Both antiseptics are chondrotoxic, but sodium hypochlorite damages human chondrocytes less than chlorhexidine in vitro. CONCLUSIONS: The findings confirm the effectiveness of sodium hypochlorite and chlorhexidine against bacterial biofilms. Both antiseptics can be recommended for the treatment of periprosthetic infections. The toxic effects of sodium hypochlorite and chlorhexidine towards chondrocytes may mean there is a risk of damage to cartilage tissue. LEVEL OF EVIDENCE: Controlled experimental study.

Low-grade infections as a possible cause of arthrofibrosis after total knee arthroplasty.

PURPOSE: Arthrofibrosis after total knee arthroplasty represents a considerable burden for the patient and a therapeutic challenge for the practitioner. One possible cause discussed in the literature is a low-grade infection. This hypothesis should be examined within the scope of this retrospective study. PATIENTS AND METHODS: Nineteen patients with clinical symptoms of arthrofibrosis after primary total knee arthroplasty were examined between January, 1999 and January, 2012. Incorrect positioning was radiologically ruled out. All patients were examined clinically (score of Freeman as well as Blauth and Jäger), radiologically (component and leg alignment, patella height according to Insall and Salvati), microbiologically (culture-based procedures), molecular biologically (PCR) and histologically in the course of an open revision of the prosthesis. RESULTS: According to the score of Freeman et al. (1977), a highly significant improvement in pain (p = 0.007) and in the overall score (p = 0.003) was shown. The knee joint mobility did not change significantly (p = 0.795). PCR was negative in 17 patients. One patient showed a PCR-positive result of the synovial membrane for Corynebacterium spp., while Staphylococcus warneri was detected in the culture. Another patient had a positive result of synovia PCR for Enterococcus cecorum as well as Corynebacterium spp. However, this culture was sterile. In 16 patient samples, no bacterial growth was detectable. Two samples were not evaluable. The main histopathological findings were synovialitis and fibrosis. CONCLUSION: The hypothesis of low-grade-infection-induced arthrofibrosis after total knee arthroplasty could not be confirmed in this study. However, based on this small study population the conclusion needs to be confirmed by new and larger studies, ideally prospectively designed including a control group.

Gait Analysis before and after Cycle Training Using a 3D Pedal System.

PURPOSE OF THE STUDY In this pilot study, gait analysis was performed before and after training with a 3D pedal system (BIUS1), in order to clarify whether these differences are detectable by gait analysis after a short period of training. MATERIAL AND METHODS Two female and three male subjects were included in a prospective case-control pilot study. The patient and training characteristics were determined. Objective measurement data of the gait were obtained by using a three-dimensional motion analysis system with six infrared cameras and three force plates before and after training with the 3D pedal system. RESULTS The mean age was 36.7 ± 8.7 years and the subjects had a BMI of 21.8 ± 2.4 kg/m 2 . The training time per year was an average of 36.0 ± 11.2 days, with a training workload of 511.4 ± 36.7 km. For time-distance parameters, improvements for the left and right side were obtained for cadence and cycle time after training. In total, there was a reduction in hip abduction angle, and an increase in hip inward rotation, knee outward rotation, and range of the frontal knee angle. CONCLUSIONS Changes in parameters in the gait analysis after a short training interval demonstrate that a 3D pedal system is suitable to produce changes in the gait pattern detectable by gait analysis. Training effects on the supposedly weaker left side can be explained after a brief application of the BIUS1 system. Key words:cycle training, 3D pedal system, gait analysis.

Long-Term Effects of Intravenous Iloprost Therapy in Patients with Bone Marrow Oedema of the Knee Joint.

PURPOSE OF THE STUDY Bone marrow oedema (BMO) syndrome is a multifactorial condition. Various conservative treatment options include analgesic therapy, immobilisation of the affected joint and/or systemic intravenous iloprost therapy. Many studies have confirmed the positive effect of iloprost therapy, but only after short-term follow-up. The purpose of this study was to show that treatment with iloprost leads to positive long-term functional and radiological outcomes for BMO of the knee. MATERIAL AND METHODS Fifteen patients with BMO of the knee joint, ARCO stage 1-2, were included in this study. Various questionnaires, the Lysholm Score, the SF-36, WOMAC, Knee Society Score, and a visual analogue pain scale (VAS), were evaluated before and after iloprost therapy. All patients underwent MRI for radiological follow-up three months after treatment. RESULTS Significant improvements were found in the Lysholm Score, SF-36, WOMAC and KSS. In 80% of patients, follow-up MRI after three months showed complete regression of the oedema. Three patients received additional surgery after a follow-up period of 33 ± 7 months. CONCLUSIONS Based on the positive results of our study, we recommend treatment with iloprost for BMO of the knee in ARCO stage 1-2 patients. Key words:iloprost, bone marrow oedema, knee joint.

Calcaneal Displacement Osteotomies - Less Soft Tissue Irritation in Lateral Compression Plate than Screws.

PURPOSE OF THE STUDY With the concept of the lateral compression plate (LLCP) a technique has been available designed to combine the advantages of a fixed-angle fixation with a complete sinking of the implant into the proximal bone. The objective of the present study was to investigate the results of the LLCP compared with classical screw osteosynthesis (SO). MATERIAL AND METHODS 31 patients with pes planovalgus who received calcaneal displacement osteotomy and osteosyntheses with screws (n = 17) or LLCP (n = 14) between 2010 and 2015 were investigated retrospectively.The ankle-hindfoot scale, Kaikkonen score, VAS, and the SF-36 were determined preoperatively as well as at the last clinical follow-up. In addition, a radiological control of osseous integration was performed in all patients 12 weeks after surgery. RESULTS With regard to clinical scores both methods depicted significant improvement. In the overall cohort there were no pseudarthroses. In the SO group 5 cases (29%) showed hardware irritation, in the LLCP group there were none. Results in the LLCP group were significantly superior in the area of the physical section of the SF 36. CONCLUSIONS Based on the results of our study, surgical treatment of stage II pes planovalgus by means of calcaneal displacement osteotomy using the LLCP is equivalent to SO with a lower incidence of hardware irritation. Key words:pes planovalgus, lateral compression plate, osteosynthesis, screw, hardware irritation. LEVEL OF EVIDENCE: Level IV, retrospective case serie.

Establishing an Interdisciplinary Compulsory Elective Subject 'Spine' in the Curriculum of the University Study Course of Human Medicine.

PURPOSE OF THE STUDY Back pain and pathologies of the spine are among the main reasons why people consult a doctor, both general practitioners and paediatricians, as well as, specifically, orthopaedists, surgeons, and neurosurgeons. This involvement of different faculties calls for a high degree of interdisciplinary co-operation. In order to mediate these aspects of spine-specific diagnostics, therapy, and research to students during their studies and to promote up-and-coming specialists, the compulsory elective subject 'Spine' was established. MATERIAL AND METHODS From the winter semester of 2013 to the winter semester of 2014, the compulsory elective subject 'Spine' was offered to interested students in the 7th semester of their studies of human medicine. The maximum number of participants per course was 16. Each course lasted four weeks. The subjects taught covered the fields of degeneration, deformities, and destruction in the specialist disciplines of orthopaedics, traumatology, neurosurgery, and rehabilitation medicine. In addition, orthopaedic technology and the local musculoskeletal and biomechanical research institute were integrated into the course. Various teaching methods were applied, including problem oriented learning, seminars, observation or consultation, and internship. At the end, the course was evaluated with regard to subjective learning success, knowledge gain, satisfaction, and interdisciplinarity. Participants were compared with all students of the semester employing an objectively structured clinical examination (OSCE). RESULTS Forty-eight students took part in the compulsory elective subject 'Spine'. The compulsory elective subject was given a positive rating in all fields. In the learning success control, all of the students had good to very good results. Students attending the elective subject performed significantly better in the objective structured clinical examination (OSCE) (p ≤ 0.001). The compulsory elective course continues to be offered in the curriculum with a slightly altered schedule. CONCLUSIONS In view of the high prevalence of patients with back pain and its associated importance in terms of healthcare policy and social relevance, our experience leads us to recommend the general integration of such a compulsory elective subject in the study of human medicine. Key words:elective subject, spine, students, spinal disorders.

A simple method of measuring the wear of explanted acetabular component inserts.

AIMS: The determination of the volumetric polyethylene wear on explanted material requires complicated equipment, which is not available in many research institutions. Our aim in this study was to present and validate a method that only requires a set of polyetheretherketone balls and a laboratory balance to determine wear. METHODS: The insert to be measured was placed on a balance, and a ball of the appropriate diameter was inserted. The cavity remaining between the ball and insert caused by wear was filled with contrast medium and the weight of the contrast medium was recorded. The volume was calculated from the known density of the liquid. The precision, inter- and intraobserver reliability, were determined by four investigators on four days using nine inserts with specified wear (0.094 ml to 1.626 ml), and the intra-class correlation coefficient was calculated. The feasibility of using this method in routine clinical practice and the time required for measurement were tested on 84 explanted inserts by one investigator. RESULTS: In order to get the mean for all investigators and determinations, the deviation between the measured and specified wear was -0.08 ml (sd 0.12; -0.21 to 0.11). The interobserver reliability was 0.989 ml (95% confidence interval (CI) 0.964 to 0.997) and the intraobserver reliability was 0.941 for observer 1 (95% CI 0.846 to 0.985), 0.983 for observer 2 (95% CI 0.956 to 0.995), 0.939 for observer 3 (95% CI 0.855 to 0.984), and 0.934 for observer 4 (95% CI 0.790 to 0.984). The mean time required to examine the samples was two minutes (sd 2; 1 to 5). CONCLUSION: The method presented here was shown to be sufficiently precise for many settings and is a cost-effective and quick method of determining the volumetric wear of explanted acetabular components. However, the measurement of wear for scientific purposes will probably continue to involve more accurate and dedicated laboratory equipment.Cite this article: Bone Joint Res 2017;6:530-534.

Cementless Total Hip Arthroplasty in Primary Myelofibrosis - a Case Report.

There is a great deal of data available, in part contradictory, on the best fixation technique to use for total hip arthroplasty (THA) in hip osteoarthritis. Both the cementless and the cemented versions offer excellent long-term outcomes - if the respective technique is applied correctly. However, as far as we know, no recommendation has been made regarding cemented vs. cementless THA in primary myelofibrosis. The case described here concerns a very active 76-year-old patient with primary myelofibrosis. This is a rare hematological disease. It develops from clonal hematopoiesis with impaired blood formation and progressive bone marrow fibrosis. An MRI scan of the patients pelvis showed a marked spotted change over all of the imaged bone. Ultimately, in preoperative planning we decided in favor of a proven cementless implant (Allofit Alloclassic cup and the CLS Spotorno stem from Zimmer). Complication-free osseous integration of the cementless implants was observed. Histologic analysis of the bone showed a focally sclerotically altered bone structure. Neither osteoporosis nor osteopenia were found. In our opinion, taking into account all other indication criteria, there is no reason not to perform a cementless THA implantation in the presence of primary myelofibrosis. Key words: hip, primary myelofibrosis, cementless, THA, total hip replacement.

[Use of dual mobility cups for revision hip arthroplasty]. / Einsatz von Dual-Mobility-Pfannen beim Hüftprothesenwechsel.

The dual mobility cup (DMC) is an increasingly important tool not only in primary but also in revision total hip arthroplasty to prevent dislocation and eventually reduce postoperative complication rates. Various studies have shown survival rates with DMCs of up to 100% with an average dislocation rate of less than 1.5% after primary hip arthroplasty and a follow-up of 10 years. In revision surgery, survival rates of up to 99% were reported with dislocation rates between 0 and 10% after an average of 5 years after implantation. This article is intended to provide an overview of the principle and function of DMCs. Furthermore, indications as well as complications are presented.

[Complications and costs in primary knee replacement surgery in an endoprosthetics centre : Influence of state of training]. / Komplikationen und Kosten in der primären Knieendoprothetik in einem Endoprothetikzentrum : Einfluss des Weiterbildungsstandes.

BACKGROUND: This work examines the hypothesis that in endoprosthesis implantation there are differences between experienced primary and senior caregivers (S-Op) and less experienced follow-up assistants (T-Op) with respect to process-relevant parameters. The main hypothesis is that compared to S­Op, T­Op cause significantly longer surgery times and thus additional operating theatre costs. As sub-hypotheses, differences in various perioperative (p-o) parameters between T­Op and S­Op were examined. MATERIALS AND METHODS: The status of the operator (senior and/or senior main operator [S-Op]) and/or postoperative CRP, perioperative blood loss, the amount of transfused erythrocyte concentrates, patient age, gender, ASA risk classification (American Society of Anesthesiologists), duration of surgery and blood transfusion, duration of inpatient stay, as well as the rates of early revision surgery and complications were recorded. A comparison of patients who had been operated by an S­Op and those who had been operated by a T­Op was made for all parameters. RESULTS: Significant differences were found with respect to the duration of surgery, the duration of the hospital stay, and CRP on the third p­o day. The T­Op required an average of 11 min more than the S­Op. CRP was significantly higher in the T­Op group only on the third p­o day, by 18 mg/l. In contrast, in the T­Op group, a blood loss of 181 ml was lower than in the S­Op group. This corresponded to a reduction of 0.26 transfused erythrocyte concentrates. There were no significant differences in complication rates between S­Op and T­Op. DISCUSSION: In the setting of a certified endoprosthetics centre, the comparison of T­Op with S­Op showed that the use of the former with at a non-increased complication rate led to a significant extension of the operating time. This leads to additional training costs in the amount of an estimated 3% of the current DRG remuneration. These additional costs are not represented adequately in the current remuneration system.

[Functional Comparison of the Outcome after Midvastus and Medial Parapatellar Surgical Approach in Total Knee Arthroplasty]. / Vergleich funktioneller Ergebnisse zwischen medialem parapatellarem und Midvastus-Zugang in der Knieendoprothetik.

There are various approaches for total knee arthroplasty (TKA). On the basis of an analysis of the clinical results, it has been demonstrated that the midvastus approach (MV) is advantageous in the early postoperative period compared to the medial parapatellar surgical approach (MPP). The aim of this investigation was therefore to investigate whether the clinical advantage of MV is reflected in the functional outcome. This single blinded, prospective, randomised study was based on a power analysis. Selected randomised patients (MPP = 10, MV = 11) were examined using an instrumental gait analysis system (VICON) preoperatively, and 5 weeks (5 W) and 6 months (6 M) after implantation. The results were compared to a healthy control group (CG = 53). Besides clinical parameters, the primary objective of this study was to measure objective gait parameters; the secondary objective was to record self-assessment (Knee Society score, WOMAC). In both treatment groups, the measurements improved during the investigation period, although most parameters did not reach the CG levels. MV gave better values for the kinetic parameters sagittal knee moment (5 W) and knee power (5 W, 6 M), as well as self-assessment (WOMAC, 6 M). Other clinical parameters were similar in the two groups. In summary, in the early postoperative period, MV led to advantages in function and in subjective behaviour in daily life. From the biomechanical point of view, the MV approach is preferable.

[Arthritis of the Medial Knee Joint Compartment]. / Die mediale Gonarthrose.

23 % of all persons older than 65 years suffer from osteoarthritis of the medial compartment of the knee joint, a very common situation in orthopaedic practice 1. As a result of the demographic trend the number of patients is expected to increase in the future. Based on specific joint biomechanics and kinematics the medial knee joint compartment is more frequently affected than the lateral. Only an understanding of the functional anatomy and underlying pathology allows a critical evaluation of different available conservative and operative treatment options. This article gives an overview of diagnostic and therapeutic strategies of osteoarthritis of the medial knee joint. Frequently performed surgeries, e.g. high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) will be presented in a comparative manner. The actual scientific evidence will be given with the goal of an evidence based therapy that is adopted to stage and pathology of osteoarthritis of the medial compartment of the knee joint.

[Total knee arthroplasty in 2014 : Results, expectations, and complications]. / Knietotalendoprothese 2014 : Ergebnisse, Erwartungen und Komplikationen.

BACKGROUND: Aseptic loosening seems to have become a minor problem in total knee arthroplasty. In contrast to that, new challenges are defined by changing patients' expectations. Beside reduction of pain and improving mobility, modern implants should not be noticed as such and should not limit sports activities. OBJECTIVES: In this paper, a summary of the development and the current situation of total knee arthroplasty (e.g., implantation numbers, hospitality, operation time, and infection rates) are provided. The data are compared in an international context. In addition, current trends and developments from recent years are shown and rated according to the literature. MATERIALS AND METHODS: The paper is based on a literature search (PubMed) and analyses of published official statistical data and expert recommendations. RESULTS: Implantation numbers have been declining gradually in Germany since 2009. In 2013, 127,077 total knee arthroplasties were implanted. In contrast, the number of revision operations has increased gradually during the last decade. In addition, hospital stay and operation time have declined. CONCLUSION: The development of implants, instruments, and operation techniques results from changing patients' expectations. All innovations must be compared against the results of well-proven techniques. The arthroplasty register may be an instrument to evaluate the results of new techniques and implants in a broad clinical application in terms of survival.

[How to determine the rotation of the femoral component]. / Rotationsbestimmung der Femurkomponente - Wie mache ich das?

The different landmarks for determination of the rotation of the femoral component are shown and specific pros and cons are discussed. The videos demonstrate how to identify them intraoperatively.

Arthroscopic-Assisted Intraosseous Balloon-Assisted Repositioning of a Tibial Plateau Fracture: A Case Report.

This is the first description of an arthroscopic-assisted intraosseous balloon-assisted repositioning and defect filling of a tibial plateau fracture. The bone defect was filled with calcium phosphate cement in a liquid/paste form. The described technique was therefore introduced in order to allow an arthroscopic control of reposition and intra-articular cement escape during defect filling. X-rays showed an exact reposition without cement escape and the clinical outcome was satisfactory.