V. Quack

Morphometric Grading of Osteoarthritis by Optical Coherence Tomography — An Ex Vivo Study

Optical Coherence Tomography (OCT) yields microscopic cross‐sectional images of cartilage in real time and at high resolution. As yet, comprehensive grading of degenerative cartilage changes based on OCT has rarely been performed. This study investigated the potential of quantitative OCT using algorithm‐based image parameters such as irregularity (OII – Optical Irregularity Index), homogeneity (OHI – Optical Homogeneity Index) and attenuation (OAI – Optical Attenuation Index) in the objective grading of cartilage degeneration. Therefore, OCT was used to image and assess 113 human osteochondral samples obtained from total knee replacements. Processing included the analysis of OII (by calculation of the standard deviation with regards to a fitted surface), of OHI (by edge detection of tissue signal changes) and of OAI (by analysis of relative imaging depth). Additionally, samples were subject to macroscopic (Outerbridge grading), biomechanical (elastic stiffness), qualitative OCT and histological evaluation (Modified Mankin grading). Significant correlations were found between all outcome measures. OII and OHI were effective in assessing cartilage surface, integrity and homogeneity, while OAI could discriminate between unmineralized and mineralized cartilage, respectively. Therefore, quantitative OCT holds potential as a diagnostic tool for more reliable, standardized and objective assessment of cartilage tissue properties.

Computer-assisted navigation in total knee arthroplasty: a review of literature.

Abstract Computer-assisted navigation surgery (CAS) has been performed in total knee arthroplasty (TKA) for approximately 10 years. This technique offers experienced and inexperienced surgeons improved control and reproducible results. Currently, 30% of primary total knee replacements are performed using the CAS technique in Germany. The main problems after total knee replacement are generally aseptic loosening, instability and infection. According to various authors, the main reason for aseptic loosening is an inadequate alignment of the mechanical limb axis. Several level I and II studies have demonstrated that CAS leads to significantly less axial deviation. Nevertheless, there are critical arguments against CAS for routine use, such as longer operation times and higher costs. Additionally, there are still no long-term results available that post a definitive statement about lower revision rates, declining numbers of aseptic loosening, cost-effectiveness and clinical outcomes following CAS.

Three-dimensional imaging and analysis of human cartilage degeneration using Optical Coherence Tomography

Optical Coherence Tomography (OCT) is an evolving imaging technology allowing non‐destructive imaging of cartilage tissue at near‐histological resolution. This study investigated the diagnostic value of real time 3‐D OCT in comparison to conventional 2‐D OCT in the comprehensive grading of human cartilage degeneration. Fifty‐three human osteochondral samples were obtained from eight total knee arthroplasties. OCT imaging was performed by either obtaining a single two‐dimensional cross‐sectional image (2‐D OCT) or by collecting 100 consecutive parallel 2‐D OCT images to generate a volumetric data set of 8 × 8 mm (3‐D OCT). OCT images were assessed qualitatively according to a modified version of the DJD classification and quantitatively by algorithm‐based evaluation of surface irregularity, tissue homogeneity, and signal attenuation. Samples were graded according to the Outerbridge classification and statistically analyzed by one‐way ANOVA, Kruskal Wallis and Tukeys or Dunns post‐hoc tests. Overall, the generation of 3‐D volumetric datasets and their multiple reconstructions such as rendering, surface topography, parametric, and cross‐sectional views proved to be of potential diagnostic value. With increasing distance to the mid‐sagittal plane and increasing degeneration, score deviations increased, too. In conclusion, 3‐D imaging of cartilage with image analysis algorithms adds considerable potential diagnostic value to conventional OCT diagnostics.

Optical coherence tomography-based parameterization and quantification of articular cartilage surface integrity

Loss of articular cartilage surface integrity is considered the earliest sign of osteoarthritis; however, its reliable detection has not been established by clinical routine diagnostics. This study comprehensively assesses a set of 11 algorithm-based 2-D Optical Coherence Tomography roughness parameters and investigates their clinical impact. Histology and manual irregularity quantification of 105 human cartilage samples with variable degeneration served as reference. The majority of parameters revealed a close-to-linear correlation with the entire spectrum of degeneration. Surface integrity should therefore be assessed by a combination of parameters to improve current diagnostic accuracy in the determination of cartilage degeneration.

Aktuelle Behandlungsstrategien der Spondylodiszitis in deutschen Akutkliniken

BACKGROUND Spondylodiscitis is a rare disease which is associated with high mortality. No guidelines for treatment exist and the available studies are not homogeneous. Attempts have been made in recent years to structure therapy using algorithms. Early recognition of the disease is above all important for its later outcome. Therapy takes place in not only orthopaedic/trauma surgery clinics but also in neurosurgical clinics. MATERIAL AND METHOD We sent an online survey on this subject to orthopaedic clinics, trauma surgery and neurosurgery clinics in Germany. The aim was to ascertain current care strategies in Germany. A further objective was to elicit differences between the specialist fields. RESULTS A total of 164 clinics responded to the survey. The response rate was 16% of the orthopaedic/trauma surgery clinics and 32% of the neurosurgical clinics. Differences between the two specialist fields can be found particularly in the use of systemic and local antibiotics, in the choice of surgical access to the thoracic spine and the lumbar spine and in post-operative imaging. In both specialist fields, patients with neurological dysfunctions are treated primarily in clinics with high case numbers. In terms of surgery, 2/3 of the responding clinics choose a one-stage operative treatment. Minimally invasive procedures and the use of cages are widespread. The participants estimate that, on the whole, a better outcome and higher patient satisfaction tend to exist after operative treatment. CONCLUSIONS The lack of homogeneity regarding treatment strategies which is indicated here clearly shows the need for therapy guidelines as an aid to orientation. This will be a challenge for the future due to the low incidence and the situation regarding currently available studies.

Strahlenfreie Diagnostik bei Skoliosen

BACKGROUND Scoliosis is a complex three-dimensional deformity of the spine, which usually occurs during childhood and adolescence. Up to now, whole spine X-rays have been the therapeutic gold standard in the diagnosis and follow-up of scoliosis. AIM This review gives a brief overview of the history, technical background and possible fields of use for video-rasterstereography METHODS Alternative measurement systems have been developed over the past few years for the treatment of scoliosis, because of the risk of radiation exposure of X-rays. The rasterstereographic system Formetric (Diers International GmbH, Schlagenbad) allows a radiation-free, three-dimensional analysis of the back surface and the spine. OUTLOOK Even dynamic measurements can now be conducted with this rasterstereographic system, which will help to further understand and analyze the human spine.ZusammenfassungHintergrundSkoliosen sind komplexe dreidimensionale Deformitäten der Wirbelsäule, die häufig im Kindes- und Jugendalter auftreten. Bis heute stellen Wirbelsäulenganzaufnahmen den therapeutischen Goldstandard in der Diagnose und Verlaufskontrolle von Skoliosen dar. Aufgrund der hiermit verbundenen Strahlenbelastung wurde bereits früh nach alternativen Messmethoden gesucht.ZielEin Überblick über die Geschichte, den technischen Hintergrund sowie über die Einsatzmöglichkeiten der Videorasterstereographie wird präsentiert.MethodeDas rasterstereographische System Formetric (Diers International GmbH, Schlagenbad, Deutschland) ermöglicht die dreidimensionale und strahlungsfreie Darstellung der Rückenoberfläche und der darunterliegenden Wirbelsäule.AusblickDurch technische Weiterentwicklungen kann diese Technik auch unter dynamischen Bedingungen eingesetzt werden, wodurch sich in der Zukunft zusätzliche Einsatzmöglichkeiten ergeben.AbstractBackgroundScoliosis is a complex three-dimensional deformity of the spine, which usually occurs during childhood and adolescence. Up to now, whole spine X-rays have been the therapeutic gold standard in the diagnosis and follow-up of scoliosis.AimThis review gives a brief overview of the history, technical background and possible fields of use for video-rasterstereographyMethodsAlternative measurement systems have been developed over the past few years for the treatment of scoliosis, because of the risk of radiation exposure of X-rays. The rasterstereographic system Formetric (Diers International GmbH, Schlagenbad) allows a radiation-free, three-dimensional analysis of the back surface and the spine.OutlookEven dynamic measurements can now be conducted with this rasterstereographic system, which will help to further understand and analyze the human spine.

Aktuelle diagnostische und therapeutische Vorgehensweise bei der primären und rezidivierenden Patellaluxation – Analyse einer bundesweiten Umfrage und der aktuellen Literatur

AIM Patellar dislocations are a common injury of the knee joint. During patella dislocations injuries of soft-tissue structures can occur that can destabilise the patella and lead to recurrent dislocations. There are also congenital pathologies that predispose to patella dislocations. In the current literature, diagnostics and treatment of patellar dislocations are frequently discussed. Therefore the aim of our survey was to analyse and summarise actual diagnostic and therapeutic strategies regarding primary and recurrent patella dislocations. METHODS An online questionnaire form was sent to 735 orthopaedic and/or trauma departments in Germany. The departments were invited to participate in an anonymous survey concerning diagnostics and treatment of primary and recurrent patellar dislocations. The questionnaire consisted of multiple choice questions and was divided into three sections. The first section included questions concerning the department structure. The second part contained questions regarding diagnostics and treatment of primary patella dislocations. The third part involved diagnostic and treatment strategies for recurrent patella dislocations. A systematic review of outcome after treatment of patellar dislocation was performed and discussed with the results of the survey. RESULTS 245 hospitals (33.3 %) returned the questionnaire. Among the participants were 23 % orthopaedic surgery departments, 32 % trauma surgery departments and 45 % combined departments. 12 % were university hospitals and 53 % academic teaching hospitals. Clinical examination was performed by nearly all participants after primary and recurrent patella dislocations. MRI was used as diagnostic tool in 81 % after primary patella dislocation and in 85 % after recurrent patella dislocation. Conventional X-rays were performed in 58 % (primary) and 51 % (recurrent patella dislocations). Computed tomography scans for measurement of the tuberositas tibiae-trochlea groove distance were used in 35 % after recurrent dislocations and in 20 % after primary patella dislocations. 69 % of the participating departments performed non-operative therapies after primary patella dislocations, especially when no associated injuries and no congenital pathologies were observed. Reconstruction of the medial retinaculum was the most frequent surgical therapy (52 %) followed by the reconstruction of the medial patellofemoral ligament (36 %) after primary patella dislocation. Following recurrent patella dislocations reconstruction of the medial patellofemoral ligament (58.5 %) was the most performed surgery and a tuberositas transfer was done in 58 % of participating departments after recurrent patella dislocation. CONCLUSION The results of our survey showed diagnostic and therapeutic procedures in the participating departments which are in accordance with recommendations in recent publications. The clinical importance of the MPFL reconstruction was observed for primary and recurrent patella dislocation. In addition, conservative treatment is still the most common treatment after primary dislocation of the patella.

Behandlungsalgorithmus der periprothetischen Infektionen am Kniegelenk

ZusammenfassungDie periprothetische Infektion am Kniegelenk ist eine seltene Komplikation. Allerdings stellt sie den Patienten und den Arzt vor große Herausforderungen. Die vergangenen Jahre haben neue Erkenntisse zur periprothetischen Infektion am Kniegelenk gebracht, die in neue Klassifikationen münden. In der vorliegenden Arbeit wird die aktuelle Literatur zur Thematik aufgearbeitet und ein neuer Therapiealgorithmus vorgeschlagen.AbstractPeriprosthetic knee joint infection is a rare complication. However, patients as well as surgeons have to deal with severe problems. The past years have brought new knowledge on periprosthetic knee joint infections which have resulted in new classifications. The present manuscript evaluates the current literature on this topic and presents a new therapeutic algorithm.Periprosthetic knee joint infection is a rare complication. However, patients as well as surgeons have to deal with severe problems. The past years have brought new knowledge on periprosthetic knee joint infections which have resulted in new classifications. The present manuscript evaluates the current literature on this topic and presents a new therapeutic algorithm.

Osteochondrosen des kindlichen Fußes

Osteochondrosis is a heterogeneous group of self-limiting conditions characterized by disturbance of enchondral ossification caused by a lack of circulation. Foot pain is a relatively common problem in children and adolescents and may be due to osteochondrosis. Osteochondrosis of the growing foot shows painful radiological alterations including increased density, fragmentation and irregularity of the epiphyses, physes and apophyses. Lacking etiologic and pathophysiologic information, ostoechondroses have been documented in almost every bone of the foot and therefore should be considered in the differential diagnosis when evaluating pediatric foot pain. The most common localizations of osteochondroses of the growing foot include the navicular as Kohlers syndrome, the metatarsal as Freibergs infraction and calcaneal apophysitis as Severs disease. Prognosis and final outcome vary considerably between the different localizations. Physicians should therefore be informed about the etiology, clinical presentation and treatment options for osteochondroses of the growing foot.ZusammenfassungOsteochondrosen sind eine heterogene Gruppe symptomatischer, selbstlimitierender Knorpel-Knochen-Veränderungen, die durch eine Störung der enchondralen Ossifikation verursacht werden. Die Ursache dieser Veränderungen an Epi-, Dia- oder Apophysen ist nicht abschließend geklärt. Es werden passagere Durchblutungsstörungen multifaktorieller Genese als Grund für die aseptische Osteochondrose diskutiert. Fußschmerzen bei Kindern und Jugendlichen sind ein häufiger Konsultationsgrund und können durch eine Osteochondrose bedingt sein. Die schmerzhaften Veränderungen der Füße gehen mit typischen radiologischen Alterationen einher. Die häufigsten Lokalisationen für Osteochondrosen am Fuß sind das Os naviculare als Morbus Köhler, die Metatarsaleköpfchen und -diaphyse als Morbus Köhler-Freiberg und die Apophysitis calcanei als Morbus Sever. Verlauf und Prognose sind je nach Lokalisation unterschiedlich. Die Aufgabe des behandelnden Arztes besteht darin, die Symptome zeitnah richtig zu deuten und eine gezielte Diagnostik einzuleiten. Der Verlauf und die erforderlichen therapeutischen Maßnahmen sind in Abhängigkeit von Lokalisation, Patientenalter und Stadium der Veränderung zu erfassen. Therapeutische Ziele sind die Reduktion von Beschwerden und bleibende, präarthrotische Deformitäten zu verhindern.AbstractOsteochondrosis is a heterogeneous group of self-limiting conditions characterized by disturbance of enchondral ossification caused by a lack of circulation. Foot pain is a relatively common problem in children and adolescents and may be due to osteochondrosis. Osteochondrosis of the growing foot shows painful radiological alterations including increased density, fragmentation and irregularity of the epiphyses, physes and apophyses. Lacking etiologic and pathophysiologic information, ostoechondroses have been documented in almost every bone of the foot and therefore should be considered in the differential diagnosis when evaluating pediatric foot pain. The most common localizations of osteochondroses of the growing foot include the navicular as Kohler’s syndrome, the metatarsal as Freiberg’s infraction and calcaneal apophysitis as Sever’s disease. Prognosis and final outcome vary considerably between the different localizations. Physicians should therefore be informed about the etiology, clinical presentation and treatment options for osteochondroses of the growing foot.

A comparative study of mechanical properties of fresh and frozen-thawed porcine intervertebral discs in a bioreactor environment

Limited availability of fresh intervertebral discs (IVDs) necessitates the use of frozen-thawed samples in biomechanical investigations. Several authors have reported the mechanical properties of frozen-thawed IVDs, but few studies have investigated the effects of storage temperature and cooling rate. The validity and reliability of the applied freezing-thawing procedures are still relatively unknown. The study aims to compare the mechanical responses of fresh porcine IVDs and porcine IVDs, which were frozen at different freezing temperatures with a controlled-rate cooling process and then thawed. The specimens were obtained from pigs aged 6 months. A total of 18 functional spine units (FSUs) were taken from seven porcine lumbar spines (L1-L6). The specimens were then split into three groups. The first group was tested fresh immediately and the other two groups were frozen at the same cooling rate and stored at -20°C and -80°C, respectively, before testing. The period of storage ranged between 12 and 43 days. The frozen specimens were thawed for 9h at room temperature before the tests. A special IVD bioreactor, which maintained the realistic behaviour of IVDs under various loading conditions, was developed. The analysis of variance (ANOVA) was used to determine if the observed results were statistically significant. The results indicated that frozen storage at -20°C decreases the comprehensive stiffness. In contrast, freezing to -80°C did not seem to have any effect on the mechanical properties of IVDs. No significant differences in outcome were observed for the samples, which had different spine levels. The study confirmed the reliability and usability of frozen-thawed samples stored at -80°C for biomechanical investigations.