Learning curves of robotic technology in an orthopedic teaching hospital.

BACKGROUND: In recent years there has been an increasing implementation of robotic technology in arthroplasty. Due to the unclear data situation the aim of this study was to analyze the learning curve for robotic technology in residency training. METHODS: After its introduction, the first 351 consecutive robotic knee replacements were prospectively included in the study. Surgical times, preoperative and postoperative radiographs, intraoperatively recorded alignment data and complications were analyzed. Satisfaction, revision, and referral rates were determined in a 90-day follow-up survey. Data from the last 350 navigated total knee arthroplasties were analyzed as a historical control group. RESULTS: A learning curve of between 3 and 53 procedures was identified, depending on the surgeon, with further reductions in time measured even after 1 year of use. The operative times of the navigated technique were achieved by all surgeons. With respect to precision (alignment outliers) and patient satisfaction rate, no learning curve was evident. Comparison between tutorial and non-tutorial surgery showed a 16-min increase in operating time, but no significant differences in precision, complications, and patient satisfaction rate. CONCLUSION: The study showed that there was a learning curve in terms of duration of surgery but not in terms of precision, complications, and patient satisfaction. Robotic tutorial surgery requires more time but provides the same outcome compared to experienced surgeons. Thus, the robotic surgical technique appears to be an excellent training tool in knee arthroplasty.

Status and future of modern technologies in arthroplasty : Results of a survey of the German Society for Orthopedics and Trauma Surgery (DGOU).

BACKGROUND: The orthopedic community is divided on the question of whether modern technologies in arthroplasty improve outcomes. Therefore, the aim of this initiative of the working group on intraoperative imaging and technology integration (Arbeitsgemeinschaft intraoperative Bildgebung und Technologieintegration, AGiTEC) is to initiate the collection of additional data for the scientific evaluation of modern technologies. QUESTION: To what extent are modern technologies currently used and which implementations are planned? Do the members of the German Society for Orthopedics and Trauma Surgery (DGOU) consider the acquisition of additional data for scientific assessment necessary? METHODS: Members of the DGOU were asked via an e­mail survey about the distribution and projected introduction of modern technologies in arthroplasty. They were also asked whether sufficient data were collected for scientific evaluation and whether acquisition of additional data in studies or arthroplasty registries were considered necessary. RESULTS: Of the 7923 probands surveyed, 428 completed the questionnaire in full (5.4%). It was found that individual implants and navigation are currently the most frequently used (31% and 29%, respectively). The largest increases in the next 2 years are projected for virtual reality and robotics (+30% and +23%, respectively), 85% of respondents indicated that insufficient data were collected for scientific evaluation, and 89% each requested initiation of multicenter studies and inclusion of technologies in the arthroplasty registry. CONCLUSION: The results of this study should motivate the scientific community, industry, and those responsible for the arthroplasty registries to collect and analyze data for the scientific assessment of modern technologies.

[Digital OR]. / Digitaler OP.

BACKGROUND: Numerous processes are involved in the orthopedic and trauma surgery operating room (OR). Technical progress, particularly in the area of digitalization, is increasingly changing routine surgical procedures. OBJECTIVE: This article highlights the possibilities and also limitations regarding this matter. MATERIAL AND METHODS: Based on the current literature this article provides insights into innovations in the areas of digitalization of surgical devices, hybrid OR, machine-2-machine networking, management systems for perioperative efficiency improvement, 3D printing technology and robotics. RESULTS: The technical possibilities for the use of digital applications in the surgical environment are rapidly increasing. Close cooperation with industrial partners is important in this context. Technologies from the automotive, gaming and mobile phone industries are being adopted. CONCLUSION: Digital technology in the OR can improve treatment quality, patient and staff safety and cost efficiency; however, the networking of devices, implementation of innovations in existing structures and the sometimes high acquisition costs are still limiting factors.

Patella alta and patellar subluxation might lead to early failure with inlay patello-femoral joint arthroplasty.

PURPOSE: With the growing interest in resurfacing procedures, several new implants have been recently introduced for isolated patello-femoral joint arthroplasty (PFA). However, not much data are available for these new techniques or about the right indications for each type of implant. METHODS: Out of a retrospective cohort of 20 inlay PFA, 11 PFA with an elevated Insall-Salvati index and an increased patello-femoral congruence angle showed an initial satisfactory result, but presented thereafter with recurrent pain and "clunk" phenomena. They were all revised after a median time of 25 months (range 8-28 months) into an onlay technique PFA and analyzed for their failure mode and revision technique. RESULTS: Clinical symptoms such as clunking, as well as abraded areas craniolateral of the inlay implant found intraoperatively, were the main observations of this study. The modified Insall-Salvati index (mISI) was significantly higher in the revised knees compared to the unrevised (median 1.8 versus 1.6; p = 0.041). VAS and KSS significantly improved after revision (median VAS reduction in pain of 4.0 points, median KSS improvement of 20.0 points; p < 0.05). CONCLUSION: Patients with high-normal patellar height index or patella alta, as well as a craniolateral type of arthritis with additional lateralization, should be considered contra-indicated for an inlay technique PFA. They could be considered for a PFA system reaching further proximal into the distal femur. An onlay PFA can be an option for early revision of failed inlay implants. The clinical relevance of this study is that patella alta and patellar subluxation are more difficult to adjust for with an inlay PFJ component. LEVEL OF EVIDENCE: Level IV.

Periarticular injections with continuous perfusion of local anaesthetics provide better pain relief and better function compared to femoral and sciatic blocks after TKA: a randomized clinical trial.

PURPOSE: Combined femoral and sciatic nerve blocks for post-operative pain management following total knee arthroplasty (TKA) improve patient satisfaction, decrease narcotic consumption and improve pain. However, accompanying motoric weakness can cause falls and related complications. We wonder whether peri-capsular injections in combination with intra-articular perfusion of local anaesthetics would result in equal or less pain without the related complications of nerve blocks. The objective of the study was to verify these aspects in a prospective randomized trial comparing both treatments. METHODS: Fifty TKA patients randomly received either a femoral (continuous) and a sciatic (single-shot) nerve block (CFNB group, 25 knees) or periarticular infiltrations and a continuous post-operative intra-articular infusion (PIAC group, 25 knees). VAS for pain, pain medication consumption, functional assessment, straight leg raising as well as KSS were recorded post-operatively for 6 days. RESULTS: VAS (p < 0.001) and KSS (p = 0.05) were significantly better for PIAC. There was increased pain following CFNB compared to PIAC. Catheters stayed for 4 days, a pain 'rebound' occurred after removing in CFNB but not after PIAC. There was no difference in regard to knee function (n.s.), but straight leg raising was significant better following PIAC. There were two falls in patients with CFNB. CONCLUSION: Peri-capsular injections combined with an intra-articular catheter provide better pain control, no rebound pain with better function and might decrease the risk of complications related to motor weakness. LEVEL OF EVIDENCE: I.

[Should we use hip-ankle radiographs to assess the coronal alignment after total knee arthroplasty?]. / Ist die postoperative Ganzbeinaufnahme nach Knie-TEP-Implantation notwendig?

BACKGROUND: There is no consensus on whether hip-ankle radiographs or rather standardized a­p knee-radiographs should be used to assess implant position and coronal alignment after total knee arthroplasty (TKA). This study investigates whether implant position and alignment after TKA can reproducibly be assessed using a­p knee-radiographs rather than hip-ankle radiographs. MATERIALS AND METHODS: This study was performed on 100 weight-bearing hip-ankle radiographs after conventional primary TKA. The true mechanical and anatomical femorotibial angle as well as coronal implant position was assessed on hip-ankle radiographs. The radiographs were then cropped to 80, 60 and 40 % of the leg-length and tibial coronal implant position, and the anatomical axis and a surrogate mechanical axis were obtained. The difference in the alignment parameters between the hip-ankle radiographs were statistically compared with the cropped radiographs and the inter-observer correlation coefficient (ICC) was calculated. RESULTS: The ICC for measurement of the mechanical femorotibial angle was higher in hip-ankle radiographs (0.95) when compared with a radiograph cropped to 40 % (0.61). There was a significant difference in the mechanical femorotibial angle between hip-ankle radiographs and any cropped radiograph. However, there were no significant differences in coronal implant position and the anatomical femorotibial angle between hip-ankle radiographs and any cropped radiograph. CONCLUSIONS: We conclude that standard a­p knee-radiographs are insufficient to assess the mechanical alignment following TKA. However, standard a­p knee-radiographs are appropriate to assess the implant position when referenced against the anatomical axes. Weight-bearing hip-ankle radiographs should be questioned as a routine after TKA.

[Partial replacement of the knee joint with patient-specific instruments and implants (ConforMIS iUni, iDuo)]. / Patientenspezifische Instrumente und Implantate beim Teilgelenkersatz des Kniegelenkes (ConforMIS iUni, iDuo).

Knee arthroplasty is a successful standard procedure in orthopedic surgery; however, approximately 20 % of patients are dissatisfied with the clinical results as they suffer pain and can no longer achieve the presurgery level of activity. According to the literature the reasons are inexact fitting of the prosthesis or too few anatomically formed implants resulting in less physiological kinematics of the knee joint. Reducing the number of dissatisfied patients and the corresponding number of revisions is an important goal considering the increasing need for artificial joints. In this context, patient-specific knee implants are an obvious alternative to conventional implants. For the first time implants are now matched to the individual bone and not vice versa to achieve the best possible individual situation and geometry and more structures (e.g. ligaments and bone) are preserved or only those structures are replaced which were actually destroyed by arthrosis. According to the authors view, this represents an optimal and pioneering addition to conventional implants. Patient-specific implants and the instruments needed for correct alignment and fitting can be manufactured by virtual 3D reconstruction and 3D printing based on computed tomography (CT) scans. The portfolio covers medial as well as lateral unicondylar implants, medial as well as lateral bicompartmental implants (femorotibial and patellofemoral compartments) and cruciate ligament-preserving as well as cruciate ligament-substituting total knee replacements; however, it must be explicitly emphasized that the literature is sparse and no long-term data are available.

[Soft tissue balanced navigation of total knee arthroplasties]. / Navigierte Implantation weichteilbalancierter Knieendoprothesen.

OBJECTIVE: Implantation of a total knee arthroplasty with a correct mechanical axis, a rectangular joint gap and a reconstructed joint line by use of an imageless computer navigation device INDICATIONS: Symptomatic gonarthrosis if non operative treatment or joint preserving operations remains ineffective CONTRAINDICATIONS: Infections; soft tissue damage in the approach area; massive instability of the collateral ligaments SURGICAL TECHNIQUE: Medial parapatellar approach to the knee joint; diminution of the patella; fixation of the reference arrays in tibia and femur; registration of leg axis, ligament balance and surface of the knee joint by use of the navigation system; tibial resection perpendicular to the mechanical axis; ligament balancing to achieve a rectangular extension gap; femoral implant planning to maintain the original joint line and reconstruct an equal joint gap in extension and flexion; femora resection perpendicular to the mechanical axis; reconstruction of the rectangular flexion gap by rotation of the femoral resection; two stage cementing technique for fixation of the original implants; check of the final mechanical axis and symmetry of the joint gap over the whole range of motion; wound closure. POSTOPERATIVE MANAGEMENT: Physiotherapy; continuous passive motion treatment; mobilization with 20 kg weight bearing with 2 crutches for 2 weeks, thereafter with 2 crutches and incremental full weight bearing for 4 weeks. RESULTS: The analysis of 582 consecutive navigated total knee arthroplasties showed one case of extension gap instability > 3 mm (0.2%) and 8 patients with flexion gap instability > 3 mm (1.4%). A too tight flexion gap was registered in 23 patients (4.4%), a too wide flexion gap in 13 cases (2.5%). The joint line was reconstructed with an average inaccuracy of 0 mm, in 17 patients the joint line was elevated > 3 mm (2.9%).

Anti-inflammatory role of glycine in reducing rodent postoperative inflammatory ileus.

BACKGROUND: Inflammatory events within the intestinal muscularis, including macrophage activation and leukocyte recruitment, have been demonstrated to participate in causing postoperative ileus. Recently, glycine has gained attention due to its beneficial immunomodulatory effects in transplantation, shock and sepsis. METHODS: Muscularis glycine receptors were investigated by immunohistochemistry. Gastrointestinal motility was assessed by in vivo transit distribution histograms with calculated geometric center analysis and jejunal circular smooth muscle contractility in a standard organ bath. The impact of glycine on the muscularis inflammatory responses to surgical manipulation of the intestine were measured by real-time PCR, nitric oxide Griess reaction, prostaglandin ELISA, Luminex and histochemistry. KEY RESULTS: Glycine-gated chloride channels were immunohistochemically localized to muscularis macrophages and postoperative infiltrating leukocytes. Preoperative glycine treatment significantly improved postoperative gastrointestinal transit and jejunal circular muscle contractility. Preoperative glycine injection significantly reduced the induction of interleukin-6 (IL-6), tumor necrosis factor-α, inducible nitric oxide synthase and intercellular adhesion molecule-1 mRNAs, which was associated with the attenuation in postoperative leukocyte recruitment. Nitric oxide and prostanoid release from the postsurgical inflamed muscularis was diminished by glycine. The secretion of the inflammatory proteins IL-6, monocyte chemotactic protein-1/chemokine ligand 2 and macrophage inflammatory protein-1α/chemokine ligand 3 were also significantly decreased by glycine pretreatment. CONCLUSIONS & INFERENCES: The data indicate that preoperative glycine reduces postoperative ileus via the early attenuation of primal inflammatory events within the surgically manipulated gut wall. Therapeutic modulation of resident macrophages by glycine is a potential novel pharmacological target for the prevention of postoperative ileus.

[Computer-assisted joint replacement surgery]. / Navigation in der Endoprothetik.

Wrong alignment of hip and knee prosthesis is a known risk factor for early loosening and revision. Meta-analyses have shown that, by use of computer navigation, outliers can be reduced significantly. Our analysis of 200 implanted knee prostheses (100 navigated procedures, 100 conventional procedures) and 60 implanted hip resurfacings (30 navigated procedures, 30 conventional procedures) yielded the same result: In total knee arthroplasty and hip resurfacing, the numbers of outliers were significantly reduced by use of computer navigation. Furthermore, in total knee arthroplasty a significantly reduced blood loss and need for blood transfusions were noted if computer navigation was used. Long term studies are required to verify if computer navigation may be an economically cost-saving procedure. So far, in our clinic every navigated operation produced extra costs of 442 Euros. In our current healthcare system no reimbursement for these additional charges exist.

Anterior dislocation of the shoulder associated with Bankart lesion in a patient with Poland's syndrome: a case report and review of the literature.

Poland's syndrome is a rare congenital entity characterized by unilateral partial or total hypoplasia of the major pectoralis muscle, breast and/or ipsilateral hand abnormalities. It has been reported in association with various structural and functional abnormalities. We report about a 23-year-old male kick-boxer with Poland's syndrome who presented in our department the history of two traumatic anterior shoulder dislocations due to boxing and self-reductions. Physical examination showed an instability of the left shoulder, and the MRI scans demonstrated a Bankart lesion. The patient had been treated with an arthroscopic Bankart repair; reattachment of the detached antero-inferior labrum down to the glenoid and repairing of the inferior gleno-humeral ligament complex. To our knowledge this is a first case report of a patient presenting with traumatic anterior shoulder dislocations due to kick-boxing associated with Poland's syndrome.

How accurate is image-free computer navigation for hip resurfacing arthroplasty? An anatomical investigation.

BACKGROUND: The existing studies concerning image-free navigated implantation of hip resurfacing arthroplasty are based on analysis of the accuracy of conventional biplane radiography. Studies have shown that these measurements in biplane radiography are imprecise and that precision is improved by use of three-dimensional (3D) computer tomography (CT) scans. To date, the accuracy of image-free navigation devices for hip resurfacing has not been investigated using CT scans, and anteversion accuracy has not been assessed at all. Furthermore, no study has tested the reliability of the navigation software concerning the automatically calculated implant position. The purpose of our study was to analyze the accuracy of varus-valgus and anteversion using an image-free hip resurfacing navigation device. The reliability of the software-calculated implant position was also determined. METHODS: A total of 32 femoral hip resurfacing components were implanted on embalmed human femors using an image-free navigation device. In all, 16 prostheses were implanted with the proposed position generated by the navigation software; the 16 prostheses were inserted in an optimized valgus position. A 3D CT scan was undertaken before and after operation. RESULTS: The difference between the measured and planned varus-valgus angle averaged 1 degrees (mean +/- SD: group I, 1 degrees +/- 2 degrees ; group II, 1 degrees +/- 1 degrees ). The mean +/- SD difference between femoral neck anteversion and anteversion of the implant was 4 degrees (group I, 4 degrees +/- 4 degrees ; group II, 4 degrees +/- 3 degrees ). The software-calculated implant position differed 7 degrees +/- 8 degrees from the measured neck-shaft angle. These measured accuracies did not differ significantly between the two groups. CONCLUSIONS: Our study proved the high accuracy of the navigation device concerning the most important biomechanical factor: the varus-valgus angle. The software calculation of the proposed implant position has been shown to be inaccurate and needs improvement. Hence, manual adjustment of the implant position in the software-planning step is frequently required.

Is a valgus position of the femoral component in hip resurfacing protective against spontaneous fracture of the femoral neck?: a biomechanical study.

The aim of our study was to investigate whether placing of the femoral component of a hip resurfacing in valgus protected against spontaneous fracture of the femoral neck. We performed a hip resurfacing in 20 pairs of embalmed femora. The femoral component was implanted at the natural neck-shaft angle in the left femur and with a 10 degrees valgus angle on the right. The bone mineral density of each femur was measured and CT was performed. Each femur was evaluated in a materials testing machine using increasing cyclical loads. In specimens with good bone quality, the 10 degrees valgus placement of the femoral component had a protective effect against fractures of the femoral neck. An adverse effect was detected in osteoporotic specimens. When resurfacing the hip a valgus position of the femoral component should be achieved in order to prevent fracture of the femoral neck. Patient selection remains absolutely imperative. In borderline cases, measurement of bone mineral density may be indicated.

Imageless navigation of hip resurfacing arthroplasty increases the implant accuracy.

Surface arthroplasty of the hip is increasingly popular. Optimising the position of the femoral component is essential to avoid early implant failures such as femoral neck fractures. Sixty hip surface replacements were retrospectively analysed. In 30 patients imageless navigation was used, and 30 patients were operated upon using conventional jigs. Accuracy, implant position, operating time, and complications have been recorded. The navigation device improved the implant position with high accuracy. Implant-shaft angles <130 degrees and uncovered cancellous bone of the superior femoral neck could be safely avoided. After a significant learning curve, navigation took 15 minutes longer than conventional implantation. No complications were found in either group. Computer-assisted navigation allowed accurate implantation of the femoral component avoiding pitfalls of hip surface replacement. From our point of view the optimal placement of the femoral component outweighs the disadvantage of a longer operating time.

[Computer-assisted joint replacement surgery. Financial and clinical impact for a specialised orthopaedic hospital]. / Navigation in der Endoprothetik. Die Kosten-Nutzen-Analyse einer orthopädischen Fachklinik.

AIM: Incorrect alignment is a known risk factor for early loosening of implants. Computer-assisted joint replacement surgery (CAS) improves the positioning of the used implants. So far there is no study comparing the improvement of radiological implant position and the extra costs for the CAS. METHOD: We therefore analysed 200 (100 navigated procedures versus 100 conventional operations) total knee replacements and 60 (30 navigated procedures versus 30 conventional operations) hip resurfacing procedures. Evaluation criteria were radiological alignment and costs produced by using computer-assisted navigation tools. RESULTS: In our series of total knee and hip resurfacing arthroplasties the number of outliers could be significantly reduced by using CAS. Patients receiving a navigated total knee replacement had a significantly lower blood loss and need for blood transfusion. The financial calculation for CAS for our specialised orthopaedic hospital showed that every CAS operation produced 442 euro extra costs per operation. So far these extra costs are not reimbursed. CONCLUSIONS: By using CAS the implant positioning is significantly improved. Total knee replacements have a lower blood loss. Due to the prolonged operation time, the leasing costs and the single use navigation tools of every navigated operation produced costs for our hospital of 442 euro. As there is so far no reimbursement of these costs, long-term survival studies are needed to reveal the superiority of the navigation method and to show an impact on the medical budget.

Reduced liver apoptosis after venous systemic oxygen persufflation in non-heart-beating donors.

Graft injury caused by warm ischemia in livers from non-heart-beating donors (NHBDs) strongly affects posttransplantation outcome and is associated with liver apoptosis, which is mediated by death receptors, such as Fas, a surface receptor of the tumor necrosis factor (TNF)-alpha family. The aim of this study was to test the ability of venous systemic oxygen persufflation (VSOP) to reduce apoptotic changes and Fas activation in the liver after warm ischemic insult in vivo. Livers of male Wistar rats were harvested 30 min after cardiac arrest from non-heart-beating donors (NHBD) with (NHBD + O2) or without (NHBD) application of gaseous oxygen during the cold storage period via the suprahepatic caval vein. After 24 h of storage in University of Wisconsin solution at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. Conventional signs of tissue damage like enzyme release and bile production showed a significantly elevated nonspecific cell injury in the NHBD group. TUNEL staining revealed increased DNA fragmentation of sinusoidal endothelial cells in the NHBD group and more apoptotic hepatocytes than in the control group. All these alterations could be almost abrogated by the use of VSOP in the NHBD + O2 group. The immunohistochemical staining of Fas antigen expression showed a significantly elevated Fas receptor expression in the NHBD and NHBD + O2 groups, in accord with an eightfold increase of Fas receptor mRNA detected by real-time reverse-transcription polymerase chain reaction (RT-PCR). These results demonstrate that the postischemic apoptotic rate of sinusoidal endothelial cells in NHBD livers can be reduced by the use of VSOP. A significant improvement in liver integrity and viability was obtained with this technique, without influencing the expression of Fas expression.