Delayed gadolinium enhanced MRI of cartilage (dGEMRIC): Molekulare MRT-Bildgebung des Hüftgelenkknorpels [Delayed gadolinium enhanced MRI of cartilage (dGEMRIC): molecular MRI of hip joint cartilage]

Factors such as instability and impingement lead to early cartilage damage and osteoarthritis of the hip joint. The surgical outcome of joint-preserving surgery about the hip joint depends on the preoperative quality of joint cartilage.For in vivo evaluation of cartilage quality, different biochemically sensitive magnetic resonance imaging (MRI) procedures have been tested, some of which have the potential of inducing a paradigm shift in the evaluation and treatment of cartilage damage and early osteoarthritis.Instead of reacting to late sequelae in a palliative way, physicians could assess cartilage damage early on, and the treatment intensity could be adequate and based on the disease stage. Furthermore, the efficiency of different therapeutic interventions could be evaluated and monitored.This article reviews the recent application of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and discusses its use for assessing cartilage quality in the hip joint. dGEMRIC is more sensitive to early cartilage changes in osteoarthritis than are radiographic measures and might be a helpful tool for assessing cartilage quality.

How accurately can the acetabular rim be trimmed in hip arthroscopy for pincer-type femoral acetabular impingement: a cadaveric investigation

PURPOSE: The purpose of this study was to evaluate the precision of central hip arthroscopy in the assessment and treatment of pincer-type femoroacetabular impingement (FAI) avoiding the posterolateral portal, with its close proximity to the main arterial blood supply of the femoral head, the medial circumflex femoral artery. METHODS: Seven human cadaveric hips underwent arthroscopic trimming of the acetabular labrum and rim along a preoperatively defined 105 degrees arc of resection for treatment of a presumed pincer-type lesion. After the arthroscopic procedure, all specimens were dissected and measured for evaluation of the location, quantity, and quality of the area undergoing resection. RESULTS: The difference between the actual and planned arc of resection was 18.7 degrees +/- 4.7 degrees (range, 2 degrees to 34 degrees). This was mainly because of a lack of accuracy in the presumed posterior starting point (PSP), with a mean deviation of 19 degrees +/- 3.4 degrees (range, 10 degrees to 36 degrees). Correlation analysis showed that variance in the arc of resection was mainly dependent on the PSP (r = 0.739, P = .058). CONCLUSIONS: Central hip arthroscopy is a feasible option in treating anterosuperior pincer-type FAI by use of the anterior and anterolateral portals only. This cadaveric study showed that there is a significant risk of underestimating the actual arc of resection compared with the planned arc of resection for posterosuperior pincer-type lesions because of the modest accuracy in determining the PSP of the resection. CLINICAL RELEVANCE: Accurate preoperative planning and arthroscopic identification of anatomic landmarks at the acetabular side are crucial for the definition of the appropriate starting and ending points in the treatment of pincer-type FAI. Whereas anterosuperior pincer-type lesions can be addressed very precisely with our technique, the actual resection of posterosuperior lesions averaged 19 degrees less than the planned resection, which may have clinical implications.

The effects of impingement and dysplasia on stress distributions in the hip joint during sitting and walking: a finite element analysis

Soft tissue damage has been observed in hip joints with pathological geometries. Our primary goal was to study the relationship between morphological variations of the bony components of the hip and resultant stresses within the soft tissues of the joint during routine daily activities. The secondary goal was to find the range of morphological parameters in which stresses are minimized. Computational models of normal and pathological joints were developed based on variations of morphological parameters of the femoral head (Alpha angle) and acetabulum (CE angle). The Alpha angle was varied between 40 degrees (normal joint) and 80 degrees (cam joint). The CE angle was varied between 0 degrees (dysplastic joint) and 40 degrees (pincer joint). Dynamic loads and motions for walking and standing to sitting were applied to all joint configurations. Contact pressures and stresses were calculated and crosscompared to evaluate the influence of morphology. The stresses in the soft tissues depended strongly on the head and acetabular geometry. For the dysplastic joint, walking produced high acetabular rim stresses. Conversely, for impinging joints, standing-to-sitting activities that involved extensive motion were critical, inducing excessive distortion and shearing of the tissue-bone interface. Zones with high von Mises stresses corresponded with clinically observed damage zones in the acetabular cartilage and labrum. Hip joint morphological parameters that minimized were 20 degrees

Exercise for osteoarthritis of the hip

BACKGROUND: Current international treatment guidelines recommending therapeutic exercise for people with symptomatic hip OA report are based on expert opinion only. OBJECTIVES: To determine whether land-based therapeutic exercise is beneficial for people with hip OA in terms of reduced joint pain and/or improved physical function. SEARCH STRATEGY: Five databases were searched from 1966 up until August 2008. SELECTION CRITERIA: All randomised controlled trials (RCTs) recruiting people with hip OA and comparing some form of land-based therapeutic exercise (as opposed to exercises conducted in the water) with a non-exercise group. DATA COLLECTION AND ANALYSIS: Three reviewers independently extracted data and assessed methodological quality. All analyses were conducted on continuous outcomes. MAIN RESULTS: Combining the results of the five included RCTs demonstrated a small treatment effect for pain, but no benefit in terms of improved self-reported physical function. Only one of these five RCTs exclusively recruited people with symptomatic hip OA. AUTHORS' CONCLUSIONS: The limited number and small sample size of the included RCTs restricts the confidence that can be attributed to these results. Adequately powered RCTs evaluating exercise programs specifically designed for people with symptomatic hip OA need to be conducted.

Valved stents for transapical pulmonary valve replacement

OBJECTIVES: Pulmonary valve insufficiency remains a leading cause for reoperations in congenital cardiac surgery. The current percutaneous approach is limited by the size of the access vessel and variable right ventricular outflow tract morphology. This study assesses the feasibility of transapical pulmonary valve replacement based on a new valved stent construction concept. METHODS: A new valved stent design was implanted off-pump under continuous intracardiac echocardiographic and fluoroscopic guidance into the native right ventricular outflow tract in 8 pigs (48.5 +/- 6.0 kg) through the right ventricular apex, and device function was studied by using invasive and noninvasive measures. RESULTS: Procedural success was 100% at the first attempt. Procedural time was 75 +/- 15 minutes. All devices were delivered at the target site with good acute valve function. No valved stents dislodged. No animal had significant regurgitation or paravalvular leaking on intracardiac echocardiographic analysis. All animals had a competent tricuspid valve and no signs of right ventricular dysfunction. The planimetric valve orifice was 2.85 +/- 0.32 cm(2). No damage to the pulmonary artery or structural defect of the valved stents was found at necropsy. CONCLUSIONS: This study confirms the feasibility of direct access valve replacement through the transapical procedure for replacement of the pulmonary valve, as well as validity of the new valved stent design concept. The transapical procedure is targeting a broader patient pool, including the very young and the adult patient. The device design might not be restricted to failing conduits only and could allow for implantation in a larger patient population, including those with native right ventricular outflow tract configurations.