Rekonstruktion des Lig.patellofemorale mediale bei patellofemoraler Instabilität

Zusammenfassung: Obwohl Instabilitäten und mechanische Fehlbelastung im patellofemoralen Gelenk sehr häufig auftreten, besteht immer noch ein ungenügendes Verständnis der Interaktionen zwischen den einzelnen mechanischen Faktoren, die die Kinematik und Stabilität des Patellofemoralgelenks beeinflussen. Die patellofemorale Stabilität wird von passiven und aktiven Faktoren beeinflusst: Der Geometrie des patellofemoralen Gelenks und den medialen und lateralen Weichteilkräften wie z.B. dem Lig.patellofemorale mediale (LPFM, passive Stabilisatoren) sowie den Muskelkräften des Streckapparats (aktive Stabilisatoren). Neben den knöchernen Strukturen sind die medialen passiven Stabilisatoren wesentlich für die patellofemorale Stabilität verantwortlich. Die Verletzung des LPFM stellt die essenzielle Verletzung im patellofemoralen Gelenk dar, ohne die eine Luxation der Patella nahezu unmöglich ist und die in ca. 90% aller erstmaligen Patellaluxationen auftritt. Da klinisch und biomechanisch gezeigt werden konnte, dass die Rekonstruktion des LPFM eine höhere Stabilität erreicht als die bisher vornehmlich durchgeführten konventionellen Eingriffe am Streckapparat, ohne gleichzeitig ein Schmerzsyndrom zu verursachen, gilt dieser Eingriff heute als Mittel der Wahl zur Patellastabilisierun

Clinical and radiological outcome of medial patellofemoral ligament reconstruction with a semitendinosus autograft for patella instability

Background: Recurrent patellar instability is a common problem after dislocation. The medial patellofemoral ligament (MPFL) contributes 40-80% of the total medial restraining forces. This study assessed the clinical and radiological outcome after a follow-up of 4years after linear MPFL reconstruction using an ipsilateral Semitendinosus tendon autograft. Study design and methods: 15 knees in 12 patients were examined with a mean of 47months after linear reconstruction of the MPFL at a mean age of 30years. 3 knees underwent previous surgery. 3 patients had mild trochlear dysplasia grade I or II, according to the classification of Dejour. If preoperative tibial tuberosity-trochlear groove distance (TTTG) was more than 15mm, patients underwent additional medialisation of the tibial tuberosity (n=8) creating a similar postoperative situation for all patients. All patients were available for a postoperative evaluation, which consisted of a subjective questionnaire, the Kujala score, and the recording of potential patellar redislocation and apprehension. Patellar height and tilt was measured on plain radiographs. Postoperative CT scans were performed in patients with an additional tibial tuberosity-transfer. Results: Postoperatively, one patient reported on recurrent bilateral redislocation. Physical examination however revealed no findings. Three knees presented with persistent patellar apprehension. Thirteen knees had improved subjectively after surgery. The mean Kujala score improved significantly from 55.0 to 85.7 points. The patellar tilt decreased significantly from 11.3° to 9.2°. Four knees had patella alta preoperatively, but only two at the latest follow-up visit. Previous surgery or additional trochlear dysplasia had no influence on the clinical outcome. Conclusion: MPFL reconstruction improves clinical symptoms, reduces the patellar tilt substantially, and may correct patella alta. Additional mild trochlear dysplasia did not compromise the outcome; however, this fact needs further attention in a larger study grou

CT changes after trochleoplasty for symptomatic trochlear dysplasia

Trochlear dysplasia is an important risk factor for patellar instability. Because of a decreased trochlear depth in combination with a low lateral femoral condyle, the patella cannot engage properly in the trochlea. Trochleoplasty is a surgical procedure, which strives to correct such bony abnormalities. The aim of this study was to describe morphological features of trochlear dysplasia and the corrective changes after trochleoplasty on CT scan. The study group consists of 17 knees with trochlear dysplasia having undergone trochleoplasty for recurrent patellofemoral dislocation at a mean age of 22.4years. The evaluation consisted in pre- and postoperative measurements on the proximal and distal trochlea on transverse CT scans in order to determine the morphological features. We measured the transverse position and depth of the trochlear groove, the transverse position of the patella, the ratio between the posterior patellar edge and the trochlear groove, the lateral patellar inclination angle, the sulcus angle, and the lateral trochlear slope. The trochlear groove lateralised a mean of 6.1mm in the proximal aspect and 2.5mm in the distal aspect of the trochlea, while the patella medialised a mean of 5mm. Preoperatively the patella was lateral in relation to the trochlear groove in 13 cases, neutral in two cases, and medial in two cases. Postoperatively it was lateral in four cases, in neutral position in seven cases, and medialised in six cases, referenced to the trochlear groove. The trochlear depth increased from 0 to 5.9mm postoperatively in the proximal aspect of the trochlea, and from 5.5 to 8.3mm postoperatively in the distal trochlea. The lateral patellar inclination angle decreased from a mean of 21.9° to a mean of 7.8°. The sulcus angle decreased from a mean of 172.1° to a mean of 133° in the proximal trochlea and from a mean of 141.9° to a mean of 121.7° in the distal trochlea. The lateral trochlear slope changed from 2.8° to 22.7° in the proximal and from 14.9° to 26.9° in the distal part of the trochlea. In the CT scan patients with trochlear dysplasia demonstrated a poor depth, or even a flat or convex trochlea with a greater sulcus and lateral trochlear slope angle, a lateralised patella to the trochlear groove with poor congruency, and a greater lateral patellar inclination angle. Trochleoplasty can correct the pathological features of trochlear dysplasia by surgically creating more normal anatomy. The goal of this surgical procedure is to steepen and lateralise the trochlear groove for a better engagement of the patell

Right Temporoparietal Gray Matter Predicts Accuracy of Social Perception in the Autism Spectrum

Individuals with an autism spectrum disorder (ASD) show hallmark deficits in social perception. These difficulties might also reflect fundamental deficits in integrating visual signals. We contrasted predictions of a social perception and a spatial–temporal integration deficit account. Participants with ASD and matched controls performed two tasks: the first required spatiotemporal integration of global motion signals without social meaning, the second required processing of socially relevant local motion. The ASD group only showed differences to controls in social motion evaluation. In addition, gray matter volume in the temporal–parietal junction correlated positively with accuracy in social motion perception in the ASD group. Our findings suggest that social–perceptual difficulties in ASD cannot be reduced to deficits in spatial–temporal integration

Origin and insertion of the medial patellofemoral ligament: a systematic review of anatomy.

PURPOSE: The medial patellofemoral ligament (MPFL) is the major medial soft-tissue stabiliser of the patella, originating from the medial femoral condyle and inserting onto the medial patella. The exact position reported in the literature varies. Understanding the true anatomical origin and insertion of the MPFL is critical to successful reconstruction. The purpose of this systematic review was to determine these locations. METHODS: A systematic search of published (AMED, CINAHL, MEDLINE, EMBASE, PubMed and Cochrane Library) and unpublished literature databases was conducted from their inception to the 3 February 2016. All papers investigating the anatomy of the MPFL were eligible. Methodological quality was assessed using a modified CASP tool. A narrative analysis approach was adopted to synthesise the findings. RESULTS: After screening and review of 2045 papers, a total of 67 studies investigating the relevant anatomy were included. From this, the origin appears to be from an area rather than (as previously reported) a single point on the medial femoral condyle. The weighted average length was 56 mm with an 'hourglass' shape, fanning out at both ligament ends. CONCLUSION: The MPFL is an hourglass-shaped structure running from a triangular space between the adductor tubercle, medial femoral epicondyle and gastrocnemius tubercle and inserts onto the superomedial aspect of the patella. Awareness of anatomy is critical for assessment, anatomical repair and successful surgical patellar stabilisation. LEVEL OF EVIDENCE: Systematic review of anatomical dissections and imaging studies, Level IV

Stronger Neural Modulation by Visual Motion Intensity in Autism Spectrum Disorders

Theories of autism spectrum disorders (ASD) have focused on altered perceptual integration of sensory features as a possible core deficit. Yet, there is little understanding of the neuronal processing of elementary sensory features in ASD. For typically developed individuals, we previously established a direct link between frequency-specific neural activity and the intensity of a specific sensory feature: Gamma-band activity in the visual cortex increased approximately linearly with the strength of visual motion. Using magnetoencephalography (MEG), we investigated whether in individuals with ASD neural activity reflect the coherence, and thus intensity, of visual motion in a similar fashion. Thirteen adult participants with ASD and 14 control participants performed a motion direction discrimination task with increasing levels of motion coherence. A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5. Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD. Response gain is controlled by excitatory-inhibitory interactions, which also drive high-frequency oscillations in the gamma-band. Thus, our data suggest that a disturbed excitatoryinhibitory balance underlies enhanced neural responses to coherent motion in ASD

Assessing composition in modeling approaches

Modeling approaches are based on various paradigms, e.g., aspect-oriented, feature-oriented, object-oriented, and logic-based. Modeling approaches may cover requirements models to low-level design models, are developed for various purposes, use various means of composition, and thus are difficult to compare. However, such comparisons are critical to help practitioners know under which conditions approaches are most applicable, and how they might be successfully generalized and combined to achieve end-to-end methods. This paper reports on work done at the 2nd International Comparing Modeling Approaches (CMA) workshop towards the goal of identifying potential comprehensive modeling methodologies with a particular emphasis on composition: (i) an improved set of comparison criteria; (ii) 19 assessments of modeling approaches based on the comparison criteria and a common, focused case study