[Preoperative management in fast-track arthroplasty]. / Prästationäres Management in der Fast-Track-Endoprothetik.

BACKGROUND: Preoperative management of patients following fast-track arthroplasty protocols includes comprehensive patient information and risk stratification. IMPLEMENTATION: Fast-track protocols have implemented interdisciplinary patient seminars to explain the disease, operation, pain management, early mobilisation and each step of the patient pathway, as well as the role of a friend or relative as a "coach" during the whole process of treatment and rehabilitation to support and encourage the patient. There is strong evidence that preoperative anxiety is reduced. Digital apps can provide further information, practical tips and instructional videos to improve functional outcomes and to reduce pain levels. RISK FACTORS: Risk factors such as malnutrition, obesity, smoking, alcohol abuse, uncontrolled diabetes, and poor dental health are associated with a higher morbidity, mortality, complication rate and a longer length of stay and have to be assessed preoperatively and optimized if possible.

[Challenges of fast-track arthroplasty in Germany]. / Herausforderungen der Fast-Track-Endoprothetik in Deutschland.

BACKGROUND: While fast-track arthroplasty has been already established in many European countries and the United States, Germany still struggles to introduce appropriate programs. This is due to a variety of reasons. REASONS: From an organizational and medical scope, the fear of alteration, the adherence to restrictions rooted in historical tradition, the reluctance to interdisciplinary cooperation, and the lack of a willingness to implement externally-guided process analysis tools, stand in the foreground. This is system related, and especially the DRG-system with the continuous devaluation of lump compensation rates in primary hip and knee arthroplasty, also in 2020, hinders the implementation. The resulting fears and concerns that an additional reduction of the length-of-stay by fast-track programs is leading to a consistent reduction of the DRG returns, are understandable. On the other hand, the disconnectedness of the ambulatory, inpatient and rehabilitation sector in Germany inhibits the introduction of fast-track programs. SOLUTIONS: A well-thought-out change-management is the basic requirement for the successfull establishment of a Fast-Track-Program. Perspectively, a rethinking towards sector-comprehensive care strategies for the implantation of a total hip or knee replacement, including the required rehabilitation procedures, has to be demanded.

[Preoperative management and patient education in fast-track arthroplasty]. / Präoperatives Management und Patientenschulung in der Fast-Track-Endoprothetik.

BACKGROUND: Patient management and education are essential for successful fast-track hip/knee arthroplasty. Individual risk stratification as well as educational seminars play an important role in optimizing preoperative risk factors. OBJECTIVES: Preoperative risk factors are discussed, and optimization strategies are highlighted in the context of the current literature. Further, our own results of an interdisciplinary patient seminar and a patient information app shall be discussed. MATERIALS AND METHODS: In addition to the authors' own strategy concerning preoperative patient management and the execution of the patient information seminar and app, the essential papers from the literature will be discussed. RESULTS: Preoperative risk factors (diabetes, obesity, anaemia, etc.) bear the danger of a prolonged length-of-stay with increased morbidity and mortality. Preoperative optimization can reduce the risk of complications and minimize the failure of the fast-track pathway. Educational seminars and patient information apps may reduce anxiety and postoperative analgesic consumption. CONCLUSION: A good preoperative patient management in fast-track arthroplasty can reduce the risk of complications and a prolonged length-of-stay. A comprehensive patient education with educational seminars and an app contributes to optimally preparing the patient for surgery.

[Anesthesiological concepts in fast-track arthroplasty]. / Anästhesiologische Konzepte in der Fast-Track-Endoprothetik.

Whereas only a few years ago the only expectation of skilful anesthesia was an undisturbed execution of surgical procedures, today this has changed to a perioperative responsibility in which all physicians involved in the treatment process try to optimize the existing circumstances and risks of the patient before, during and after surgery. Thus, the tasks for the anesthesiologist have been mainly extended to a rapid recovery strategy with as few side effects as possible, such as nausea and vomiting or postoperative cognitive deficits (POCD). The establishment of evident structures and the introduction of suitable perioperative procedures with the goal of maintaining homeostasis, adequate opioid-sparing pain treatment and rapid postoperative convalescence determine the anesthesiological fast-track concept.

[Fast track strategies in hip arthroplasty]. / Fast-Track-Strategien in der Hüftendoprothetik.

BACKGROUND: Fast track arthroplasty is becoming increasingly accepted in German-speaking countries. By optimizing treatment processes fast track programs promise faster recovery, increased patient satisfaction, quality improvement and reduction in the length of hospital stay. OBJECTIVES: The philosophy and treatment principles of fast track hip arthroplasty during the pre, intra and postoperative phase are described in the light of the current body of evidence. The challenges concerning fast track arthroplasty within the German health system are discussed. MATERIAL AND METHODS: Besides presenting our own data concerning a patient seminar and an opiate saving pain treatment, the most relevant literature related to fast track hip arthroplasty from a pubmed search is discussed. RESULTS: Fast track concepts can only be successfully implemented through close interdisciplinary team work. Preoperatively, a patient seminar can help to prepare patients better for surgery. Postoperatively, early mobilisation and pain treatment play a central role, whereat a clear reduction in opiate application can be achieved. CONCLUSION: Fast track hip arthroplasty makes rethinking with respect to traditional treatment principles necessary and demands a high degree of interdisciplinary team work. Particularly, as result of the specifics of the health system (DRG system and stationary rehabilitation), a nationwide establishment in Germany has not taken place so far.

[Cell-based and future therapeutic strategies for femoral head necrosis]. / Zellbasierte und zukünftige Therapieansätze der Femurkopfnekrose.

BACKGROUND: The application of cell- and growth factor-based techniques in conjunction with conventional surgical approaches has great therapeutic potential for the treatment of avascular necrosis of the femoral head (AVNFH). OBJECTIVES: This review provides an overview of new strategies for the treatment of AVNFH, with emphasis on cell and growth factor-based approaches. MATERIALS AND METHODS: The results of a literature search are summarised, the most relevant publications are presented and discussed by the authors. RESULTS: In the focus of new strategies for treatment of AVNFH are bone marrow-derived cell concentrates and ex vivo-expanded mesenchymal stem cells. Besides local application during core decompression, the systemic administration of cells via blood vessels supplying the femoral head is an interesting approach. The application of osteogenic and angiogenic growth factor-laden scaffold materials has also been clinically tested. Initial results of randomised clinical trials using cell- and growth factor-based approaches underline the potential of these innovative therapeutic strategies. Cell-based therapies are governed by EU law and generally require a manufacturing authorization. CONCLUSION: To date, only few randomized controlled clinical trials are available which additionally display a considerable diversity concerning cell parameters, cell processing, adjuvant surgical techniques and the quality outcome parameters. Therefore, a final statement about the effectiveness of new cell and growth factor-based strategies is currently not possible.

[New experimental strategies in cartilage surgery]. / Neue experimentelle Ansätze in der Knorpelchirurgie.

BACKGROUND: Cell and growth factor based strategies bear great potential to support the healing processes in cartilage repair and the therapy of osteoarthritic joints. OBJECTIVES: The following review provides an overview of novel experimental strategies for the therapy of focal cartilage defects and osteoarthritis, with emphasis on cell and growth factor based approaches. MATERIALS AND METHODS: The authors summarize their own data regarding the intraarticular injection of stem cells to treat osteoarthritis of the knee and provide a synopsis of the available literature discussing the most significant publications. RESULTS: The development of novel strategies for the treatment of focal and arthrotic cartilage lesions focuses on the application of growth factors, platelet rich plasma (PRP), bone marrow (BMSAC) or adipose derived (stromal vascular fraction - SVF) cell concentrates, and ex vivo expanded mesenchymal stem cells (MSC). First clinical data on the use of expanded MSCs show the potential of this innovative therapeutic strategy. These approaches, however, are governed by EU law and often require approval by regulatory bodies. CONCLUSION: Currently, only a limited number of published, randomized, controlled trials available. Therefore, it is not possible to finally assess the efficacy of these strategies at this point in time.

S3-Guideline non-traumatic adult femoral head necrosis.

INTRODUCTION: The treatment of adult non-traumatic avascular necrosis of the femoral head (AVN; N-ANFH) within an estimated incidence of 5000-7000 cases per annum in Germany remains a challenge. Risk factors include steroids, alcohol abuse, chemotherapy and immunosuppressive medication, but a genetic predisposition has been suggested. Early diagnosis of this often bilateral disease process is essential for successful conservative or joint preserving surgical management. In this review, we present the update German consensus S3 guideline "diagnosis and management for N-ANFH" as a concise summary. MATERIALS AND METHODS: This systematic review is based on the published literature from January 1, 1970 to April 31, 2013 (German and English language). Inclusion criteria were systematic reviews, meta-analyses and relevant peer review publications. We identified a total of 3715 related publications, of which 422 were suitable according to the SIGN criteria, but only 159 fulfilled our inclusion criteria. RESULTS AND CONCLUSIONS: Clinical suspicion of N-ANFH mandates radiographic evaluation. If radiographs are normal MRI scans are recommended, which should be evaluated according to the ARCO-classification. Differential diagnoses include transient osteoporosis, bone bruise, insufficiency fracture and destructive arthropathy. Untreated, subchondral fractures commonly occur within 2 years, during which the risk for contralateral involvement is high-thereafter unlikely. Conservative management with Ilomedin and Alendronat can be tried, but other pharmacological or physical treatments are inappropriate. No specific joint preserving procedure can be recommended, but core decompression should be considered in early stages if necrosis is <30 %. In ARCO stages IIIc or IV total hip arthroplasty (THA) should be contemplated, which offers similar outcome compared to osteoarthritis. Young age is the main risk factor for higher revision rates after THA for N-ANFH.

[Extensor mechanism complications in revision total knee arthroplasty : Joint exposure and prevention of extensor mechanism complications]. / Komplikationen am Streckapparat in der Revisionsknieendoprothetik : Exposition und Vermeidung von Komplikationen am Streckapparat.

BACKGROUND: Revision total knee arthroplasty is complex surgery that has to be well planned from its indication to the actual surgical procedure. OBJECTIVES: To review surgical techniques that allow a secure exposure of the joint in revision total knee arthroplasty. MATERIALS AND METHODS: The authors summarize a review of the literature and present their own experience in knee joint exposure aiming to minimize extensor mechanism complications in revision TKA. RESULTS: The choice of adequate skin incision, detailed scar removal and a systematic soft tissue release are inevitable prerequisites for an optimal joint exposure and the minimization of extensor mechanism complications. In most patients, a medial parapatellar arthrotomy is sufficient to expose the knee joint and, if necessary, allows a proximal extension using a quadriceps snip or VY-quadricepsplasty, or a distal extension via a tibial tubercle osteotomy. Whether the quick and easy quadriceps snip or a tibial tubercle osteotomy has to be performed depends in each case on the extent of scar formation, the extensor mechanism contracture and the preoperative position of the patella. In general, a parapatellar and lateral release has to be executed; therefore, a partial lateral facetectomy ensures a secure eversion of the patella. Alternative approaches to access the joint do not reveal significant advantages and play a minor role in revision total knee arthroplasty. CONCLUSION: Revision total knee arthroplasty is a challenging surgical procedure. In addition to the regular soft tissue release techniques and joint approaches, the surgeon has to be aware of proximal and distal extension procedures to securely expose the joint and minimize the risk of extensor mechanism complications.

[Patellar tendon injuries after total knee arthroplasty : Classification and management]. / Rupturen der Patellarsehne nach Kniegelenkersatz : Klassifikation und Management.

BACKGROUND: Ruptures of the patellar tendon after total knee arthroplasty represent a rare but severe complication, which in general requires surgical therapy. OBJECTIVES: To implement a classification and correspondent therapy algorithm in consideration of the current literature for the treatment of patellar tendon ruptures after TKA. MATERIAL AND METHODS: A review of the recent literature and the author's experience are summarized in a classification and correspondent therapy algorithm for the treatment of patellar tendon ruptures after TKA. RESULTS: Ruptures of the patella tendon can be classified as avulsions (Type I), acute (Type II) and chronic ruptures (Type III). Avulsions are often of iatrogenic nature and can be sufficiently treated by transosseous refixation prior to implantation of the revision TKA. Acute ruptures of the patellar tendon can originate from trauma or intraoperative injury. The rupture can be restored by primary suture in combination with a wire cerclage in the case of good tendon quality and the absence of patient comorbidities (Type IIA). In the case of poor tendon quality or existing comorbidities (Type IIB) additional augmentation of the ruptured tendon, utilizing the autologous semitendinosus/gracilis tendon, is recommended. Chronic ruptures revealing a good patellar bone stock (Type IIIA) can be treated by a combination of a semitendinosus augmentation and a turndown quadriceps tendon flap. In the case of a poor patellar bone stock (Type IIIB) transpatellar fixation of the semitendinosus tendon is virtually impossible, so that an allograft augmentation or the use of a soft tissue muscle flap (i. e. the gastrocnemius flap) has to be considered. A failed complex reconstruction with or without infection (Type IIIC) is an invidious surgical task and needs to be addressed by the utilization of a muscle flap, an allograft or a patellectomy with or without arthrodesis.

Functional cartilage repair capacity of de-differentiated, chondrocyte- and mesenchymal stem cell-laden hydrogels in vitro.

OBJECTIVE: The long-term performance of cell-seeded matrix-based cartilage constructs depends on (1) the development of sufficient biomechanical properties, and (2) lateral integration with host tissues, both of which require cartilage-specific matrix deposition within the scaffold. In this study, we have examined the potential of tissue-engineered cartilage analogs developed using different cell types, i.e., mesenchymal stem cells (MSCs) vs chondrocytes and de-differentiated chondrocytes, in an established "construct in cartilage ring" model. DESIGN: Cell-laden constructs of differentiated chondrocytes, de-differentiated chondrocytes after two, five or eight population doublings, and MSCs were either implanted into a native cartilage ring immediately after fabrication (immature group) or pre-treated for 21 days in a transforming growth factor-ß3 (TGF-ß3) containing medium prior to implantation. After additional culture for 28 days in a serum-free, chemically defined medium, the extent of lateral integration, and biochemical and biomechanical characteristics of the implants as hybrid constructs were assessed. RESULTS: The quality of integration, the amount of accumulated cartilage-specific matrix components and associated biomechanical properties were found to be highest when using differentiated chondrocytes. De-differentiation of chondrocytes negatively impacted the properties of the implants, as even two population doublings of the chondrocytes in culture significantly lowered cartilage repair capacity. In contrast, MSCs showed chondrogenic differentiation with TGF-ß3 pre-treatment and superior integrational behavior. CONCLUSIONS: Chondrocyte expansion and de-differentiation impaired the cell response, resulting in inferior cartilage repair in vitro. With TGF-ß3 pre-treatment, MSCs were able to undergo sustained chondrogenic differentiation and exhibited superior matrix deposition and integration compared to de-differentiated chondrocytes.

[Post-treatment rehabilitation after autologous chondrocyte implantation: State of the art and recommendations of the Clinical Tissue Regeneration Study Group of the German Society for Accident Surgery and the German Society for Orthopedics and Orthopedic Surgery]. / Nachbehandlung bei der autologen Chondrozytentransplantation: Eine Bestandsaufnahme und Empfehlung der AG Klinische Geweberegeneration der DGU/DGOOC.

BACKGROUND: Over the course of the past two decades autologous chondrocyte implantation (ACI) has become an important surgical technique for treating large cartilage defects. The original method using a periostal flap has been improved by using cell-seeded scaffolds for implantation, the matrix-based autologous chondrocyte implantation (mb-ACI) procedure. MATERIAL AND METHODS: Uniform nationwide guidelines for post-ACI rehabilitation do not exist. A survey was conducted among the members of the clinical tissue regeneration study group concerning the current rehabilitation protocols and the members of the study group published recommendations for postoperative rehabilitation and treatment after ACI based on the results of this survey. RESULTS: There was agreement on fundamentals concerning a location-specific rehabilitation protocol (femoral condyle vs. patellofemoral joint). With regard to weight bearing and range of motion a variety of different protocols exist. Similar to this total agreement on the role of magnetic resonance imaging (MRI) for postsurgical care was found but again a great variety of different protocols exist. CONCLUSIONS: This manuscript summarizes the recommendations of the members of the German clinical tissue regeneration study group on postsurgical rehabilitation and MRI assessment after ACI (level IVb/EBM).

[Nerve lesions after minimally invasive total hip arthroplasty]. / Nervenläsionen nach minimal-invasiver Hüftendoprothetik.

Although there is no clear evidence, minimally invasive hip arthroplasty seems to be associated with slightly higher complication rates compared to standard procedures. Major nerve palsy is one of the least common but most distressing complications. The key for minimizing the incidence of nerve lesions is to analyze preoperative risk factors, accurate knowledge of the anatomy and minimally invasive techniques. Once clinical signs of nerve injury are evident, the first diagnostic steps are localization of the lesion and quantification of the damage pattern. Therefore, clinical assessment of the neurological deficits should be performed as soon as possible. Apart from rare cases of isolated transient conduction blockade or complete transection, the damage pattern is mostly combined. Thus, there can be evidence for dysfunction of nerve conduction (neuropraxia) and structural nerve damage (axonotmesis or neurotmesis) simultaneously. Because the earliest signs of denervation are detectable via electromyography after 1 week, it is not possible to make any reliable prognosis within the first days after nerve injury using electrophysiological methods. This review article should serve as a guideline for prevention, diagnostics and therapy of neural lesions in minimally invasive hip arthroplasty.

[MRI-based measurement of muscle damage after minimally invasive hip arthroplasty]. / MRT-basierte Messung des Muskelschadens nach minimal-invasiver Hüftprothesenimplantation.

Muscle trauma in minimally invasive hip arthroplasty using a direct anterior approach was assessed by magnetic resonance imaging (MRI) in 25 patients preoperatively, as well as 6 months after total hip replacement. The MRI evaluation included the measurement of changes in muscle cross-sectional area (CSA = atrophy) and fatty infiltration of the muscles. Using MRI, preoperatively existing and operatively caused muscle tissue damage could be detected by assessing changes in muscle CSA and fatty infiltration. Even preoperatively, a muscular atrophy and fatty infiltration could be demonstrated in the diseased hip. Using the minimally invasive direct anterior approach, a postoperative significantly reduced CSA and significantly increased fatty degeneration was detected for the M. tensor fasciae latae and the M. glutaeus minimus. No increased damage of the M. glutaeus medius could be detected.

[Minimally invasive anterior approach]. / Der minimal-invasive anteriore Zugang.

The minimally invasive direct anterior approach for total hip arthroplasty (THA) was first published in 1985. Since then the technique has been further improved and the indications have been extended. The approach utilizes the muscle gap between the tensor fasciae latae muscle on the lateral side and the sartorius muscle on the medial side. This muscle gap allows a direct and quick approach to the hip joint with good muscle preservation. During preparation of the femur the tensor fasciae latae muscle is at risk of being damaged. The lateral cutaneous nerve of the thigh (NCFL) and its branches are also in danger of being damaged during skin incision and dissection of the subcutaneous tissue. In this article the technique, risks and current clinical results of THA using the minimally invasive direct anterior approach are described. The results from the literature, as well as own results are compared to the traditional transgluteal lateral Bauer approach and discussed. Reviewing the literature, special attention has been given to the incidence of NCFL lesions, damage of the tensor fasciae latae muscle and positioning of the cup. Especially for the latter, the general view is hindered in the minimally invasive technique.

[Reconstruction of osteochondral defects with a collagen I hydrogel. Results of a prospective multicenter study]. / Rekonstruktion von Gelenkknorpeldefekten mit einem Kollagen-I-Hydrogel. Ergebnisse einer prospektiven Multicenterstudie.

STUDY GOALS: The aim of the study was to evaluate the therapeutic benefit of CaReS®, a type I collagen hydrogel-based autologous chondrocyte implantation technique, for the treatment of osteochondral defects of the knee (Outerbridge grades III and IV) within a prospective multicenter study. MATERIAL AND METHODS: A total of 116 patients in 9 clinical centers were treated with CaReS between 2003 and 2008. The Cartilage Injury Evaluation Package 2000 of the International Cartilage Repair Society (ICRS) was employed for data acquisition and included the subjective International Knee Documentation Committee score (IKDC score), the pain level (visual analog scale, VAS), the physical and mental SF-36 score, the overall treatment satisfaction and the functional IKDC status of the indexed knee. Follow-up evaluation was performed 3, 6 and 12 months after surgery and annually thereafter. RESULTS: The mean defect size treated was 5.4 ± 2.7 cm(2) with 30% of the cartilage defects being ≤4 cm(2) and 70% ≥4 cm(2). The mean follow-up period was 30.2 ± 17.4 months (minimum 12 months and maximum 60 months). The mean IKDC score significantly improved from 42.4 ± 13.8 preoperatively to 70.5 ± 18.7 (p < 0.01) in the mean follow-up period. Global pain level significantly decreased (p < 0.001) from 6.7 ± 2.2 preoperatively to 3.2 ± 3.1 at the latest follow-up. Both the physical and mental components of the SF-36 score significantly increased. At the latest follow-up 80% of the patients rated the overall treatment satisfaction as either good or very good. The functional IKDC knee status clearly improved from preoperative to the latest follow-up when 23.4% of the patients reported having no restriction of knee function (I), 56.3% had mild restriction (II), 17,2% had moderate restriction (III) and 3.1% revealed severe restriction (IV). CONCLUSIONS: The CaReS technique is a clinically effective and safe method for the reconstruction of isolated osteochondral defects of the knee joint and reveals promising clinical outcome up to 5 years after surgery. A longer follow-up period and larger patient cohorts are needed to evaluate the sustainability of CaReS treatment.

[Bone tissue engineering. Reconstruction of critical sized segmental bone defects in the ovine tibia]. / Knochen-Tissue-Engineering. Rekonstruktion segmentaler Knochendefekte kritischer Größe in der Schafstibia.

Well-established therapies for bone defects are restricted to bone grafts which face significant disadvantages (limited availability, donor site morbidity, insufficient integration). Therefore, the objective was to develop an alternative approach investigating the regenerative potential of medical grade polycaprolactone-tricalcium phosphate (mPCL-TCP) and silk-hydroxyapatite (silk-HA) scaffolds.Critical sized ovine tibial defects were created and stabilized. Defects were left untreated, reconstructed with autologous bone grafts (ABG) and mPCL-TCP or silk-HA scaffolds. Animals were observed for 12 weeks. X-ray analysis, torsion testing and quantitative computed tomography (CT) analyses were performed. Radiological analysis confirmed the critical nature of the defects. Full defect bridging occurred in the autograft and partial bridging in the mPCL-TCP group. Only little bone formation was observed with silk-HA scaffolds. Biomechanical testing revealed a higher torsional moment/stiffness (p < 0.05) and CT analysis a significantly higher amount of bone formation for the ABG group when compared to the silk-HA group. No significant difference was determined between the ABG and mPCL-TCP groups. The results of this study suggest that mPCL-TCP scaffolds combined can serve as an alternative to autologous bone grafting in long bone defect regeneration. The combination of mPCL-TCP with osteogenic cells or growth factors represents an attractive means to further enhance bone formation.

[Total hip replacement in developmental dysplasia: anatomical features and technical pitfalls]. / Hüftgelenkendoprothetik bei kongenitaler Dysplasie: Anatomische Besonderheiten und technische Stolpersteine.

Total hip arthroplasty is the procedure of choice for most patients with advanced, symptomatic osteoarthritis due to congenital dysplasia of the hip. However, the complexity of arthroplasty is significantly increased because of anatomic abnormalities associated with dysplasia of the hip. In addition the relatively young age of patients may affect survival of the implant. From a biomechanical standpoint the primary surgical objective is reconstruction of the anatomical center of rotation. Independent of the pelvic bone stock the socket should be located as near as possible to the anatomical acetabular location. There are various operative strategies to ascertain sufficient stability of the socket. The anterolateral deficiency of the acetabulum can be reconstructed by bulk femoral autografting or bone impaction grafting. Furthermore controlled perforation of the medial wall or implantation of reinforcement rings and oval sockets have been described. Cementless, biological socket fixation shows superior long-term results compared to cemented cups, especially in these young patients. The location of the reconstructed acetabulum and the desired leg length influence the type of femoral reconstruction and in some cases femoral shortening is required. In this article endoprosthetic reconstructive options for developmental dysplasia of the hip are discussed depending on the femoral and acetabular deformity.