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Biomedical subjects

J Hassenpflug

Publications and source records attributed to J Hassenpflug.

At least 19 recordsLinked to original sources
PubMed2003

[Dislocated fracture of the lesser trochanter with malrotation of the stem after robot assisted implantation of a cementless hip prosthesis: a casuistic report].

This paper presents the case of a 63 year old female with a severe coxarthrosis. She got a robot assited implantation of a cementless hip prosthesis (Osteolock, Stryker-Howmedica, Mühlheim). As operation robot the CASPAR-System (Orto-Maquet, Rastatt) was used. Initially, the clinical progress of the patient was fine. She was nearly painfree within 14 days and showed an acceptable range of motion in the operated joint (flexion/ extension 90 degrees /05 degrees /00 degrees ). She was mobilized with crutches and 15 kg weight bearing at the operated leg. 3 weeks postoperative the patient complaint about increasing pain without trauma or intensification of the weight bearing. X-rays showed not only a dislocated fracture of the lesser trochanter, but also a sinking combined with a malrotation of the stem. A revision operation was necessary,where we implanted a cemented stem. Now clinical progress was completely satisfying.

Arthroplasty, Replacement, Hip↗
PubMed2003

[Constrained knee prostheses].

There is great controversy over constrained knee prostheses, both from a clinical and a theoretical point of view. Hinged prostheses show disadvantages such as the large implant volume, a potentially higher risk of infection, and long intramedullary stems, which are difficult to remove in cases of revision surgery. However, there are advantages as well such as simple operative procedure for implantation, primary stability without need for soft tissue balancing, and greater femorotibial congruency based on the monocentric axes for flexion/extension. Clinical long-term results remain contradictory. Implantation of a constrained prosthesis makes sense as a primary implant in elderly patients, for severe defects, deformities, and instabilities, or as a revision implant.

Age Factors↗
PubMed2003

[Biomechanical examinations of the efficacy of wrist guards in inline skating].

INTRODUCTION: Fractures of the wrist and forearm are the most frequent injuries in Inline-Skating. Clinical experience has shown that these injuries can be prevented the use of wrist protectors. But various authors have shown that fractures can also occur despite the use of wrist protectors. Aim of this study was to examine different wrist protectors in a biomechanical set up. METHOD: A standardized trauma was simulated using an artificial hand with a certain weight. The forces with or without protective devices have been recorded by a force moment sensor. The results of different protectors have been compared. RESULTS: A mean force of 956 N was measured without the use of a protective device. With the application of a wrist protector these forces were reduced between 4 and 20 %. The best values have been reached with models with a strong base plate. CONCLUSIONS: The results of the present study may explain the clinical observation that wrist and forearm fractures can occur despite the use of a wrist guard. The protective effect of a wrist protector depends highly on the model that is used.

Athletic Injuries↗
PubMed2002

[Prevention of lower extremity injuries in handball: initial results of the handball injuries prevention programme].

INTRODUCTION: Injuries of the lower extremity lead to disability to perform sports and may cause degenerative changes of the joints. Hence, we developed a specific injury prevention programme for European team handball and tested this programme in a prospective study. METHOD: One handball team (2 nd division) performed a proprioceptive and neuromuscular training during the preseason. The programme consists of 3 different components: 1. Information on injury mechanisms, 2. Proprioceptive training, and 3. Jump training. During the season the exercises have been continued with lower intensity. Another handball team which performed no injury prevention training served as control. Injuries were recorded in a prospective manner. In a retrospective arm of the study we compared the frequency of severe injuries of the training season with the frequency of severe injuries during the last season. RESULTS: In comparison to the last year no player from the prevention training team suffered a severe injury of the ankle or the knee. During the last season three athletes ruptured their anterior cruciate ligament. In the untrained control group one athlete suffered from an ACL rupture and one athlete had a rupture of the lateral ankle ligaments. These findings have no statistical significance because of the low number of individuals investigated. However, the incidence of light and medium injuries was significantly lower in the injury prevention group. CONCLUSIONS: This study demonstrates that proprioceptive and neuromuscular training is appropriate for the prevention of lower extremity injuries. Prevention strategies should be included in routine handball training programmes.

Adult↗
PubMed2002

The arterial supply of the lesser metatarsal heads: a vascular injection study in human cadavers.

The possibility of avascular changes of the metatarsal heads following forefoot surgery has been previously documented. The aim of this study was to investigate the arterial supply of the lesser metatarsal heads with regard to osteotomies of these bones. We used epoxy resin injections and a modified Spalteholz technique in human cadaveric specimens to demonstrate the intraosseous and extraosseous blood supply of the lesser metatarsals. The metatarsal heads had two arterial sources: 1. The dorsal metatarsal arteries, which arose from the dorsalis pedis artery, and 2. The plantar metatarsal arteries, which are branches of the posterior tibial artery. These two vessels typically anastomosed at two sites about the metatarsal heads, forming a vascular ring and provided an extensive extraosseous arterial network around the metatarsal heads. Small arterial branches of this network run distally on the metatarsal cortex to enter the bone of the metatarsal head. The nutrient arteries traversed the cortex of the metaphysis close to the capsular and ligamentous insertions to provide multiple branches for the supply of the subchondral bone. Extensive capsular stripping during metatarsal head osteotomies results in damage to the medial and lateral head vessels.

Aged↗
PubMed2001

Magnetic resonance arthrography of the acetabular labrum: value of radial reconstructions.

The intention was to compare the sensitivity and specificity of radial planes with oblique coronal and oblique axial planes for the detection of labral abnormalities of the acetabulum on magnetic resonance arthrography (MRa). Twenty cadaveric hip joints were examined by radiography and MRa. For MRa, 15 ml of a solution of iodinated contrast material and gadolinium diethylene triamine tetra-acetic acid (Gd-DTPA; 100:1) were injected under fluoroscopic guidance. MRI was performed on a 1.5-T MR scanner with a fat-suppressed 3D-FLASH sequence (TR/TE/flip-angle 42 ms/10 ms/40 degrees; field of view 16 cm, matrix 256 x 256, section thickness 1.5 mm, pixel size 0.7 x 0.7 mm). Multiplanar image reconstructions were done perpendicular to the acetabulum in oblique coronal and oblique axial planes and in radial planes. Macroscopic and histopathologic examination of the labral specimens was performed. Labral lesions were found in 15/20 hips (75%) on pathologic examination. Six hips demonstrated labral degeneration. The labrum was partially detached in 7 hips and completely detached in 2 hips. A flap-like labrum was found in 2 cases, 1 with partial detachment of the labrum and 1 with a degenerated labrum. Using oblique coronal and oblique axial reconstructions, pathologic findings were confirmed by MRa in 9/15 specimens (sensitivity 60%). There were no false-positive findings (specificity 100%, accuracy 70%). Also, 3/6 labral degenerations without detachment, 4/7 partial detachments, and 2/2 complete detachments were correctly diagnosed. Two flap-like labra were not recognized. With radial reconstructions, pathologic findings were correctly confirmed in 12/15 specimens (sensitivity 80%) without false-positive findings (specificity 100%, accuracy 85%). Also, 3/6 labral degenerations without detachment, 6/7 partial detachments, 2/2 complete detachments, and 1/2 flap-like labra were correctly diagnosed. MRa of the acetabular labrum using radial reconstructions is well suited to delineate the acetabular labrum and to diagnose labral detachments. Radial reconstructions allow for perpendicular display of the whole acetabular circumference and are more accurate for the diagnosis of acetabular labral lesions, when compared with oblique coronal and oblique axial reconstructions.

Acetabulum↗
PubMed2001

Combination of reduced oxygen tension and intermittent hydrostatic pressure: a useful tool in articular cartilage tissue engineering.

Cartilage cells are normally studied under atmospheric pressure conditions and without loading. However, since cartilage exists in a condition of reduced oxygen and intermittent hydrostatic pressure we hypothesized lower partial oxygen pressures (PO2) and different intermittent hydrostatic pressures (IHP) would increase articular chondrocyte proliferation and matrix production and to stabilize chondrocyte phenotype in vitro. Monolayers of adult bovine articular chondrocytes were cultured under 5% or 21% PO2 in combination with IHP (0.2 MPa amplitude, frequencies 5/5s = 0.1 Hz, 30/2 or 2/30 min on/off loading). We measured proliferation (3H-thymidine incorporation) and collagen secretion (protein-binding assay, collagen type II-ELISA and immunocytochemical staining of pericellular collagen types I, II and IX). Reduced PO2 stimulated proliferation and collagen type II and IX secretion of chondrocytes in comparison to 21% PO2. Additionally, collagen type I expression was delayed by low PO2, indicating a stabilization of the cell phenotype. IHP 5/5s and 30/2 min inhibited proliferation but increased collagen secretion (pericellular collagen type IX was decreased). IHP 30/2 min delayed first expression of collagen type I. In contrast, IHP 2/30 min increased proliferation, but lowered collagen expression. All stimulating or inhibiting effects of PO2 and IHP were additive and vice versa. Reduced PO2 and different settings of IHP increased proliferation, collagen secretion, and phenotype stability of chondrocytes. The oxygen- and IHP-induced effects were additive, suggesting that a combination of these parameters might be a useful tool in cartilage tissue engineering.

Animals↗
PubMed2001

Immunohistochemical detection of estrogen receptor alpha in articular chondrocytes from cows, pigs and humans: in situ and in vitro results.

Clinical observations suggest that estrogens are involved in the pathogenesis of postmenopausal osteoarthritis, but only little is known about the influence of these hormones on articular cartilage cells. The effect of estradiol is mediated by estrogen receptors alpha and beta. The goal of the present study was to search for estrogen receptor alpha in articular tissue from cows, pigs and humans by immunohistochemistry to form a basis for in vitro studies. In addition, we also tried to detect estrogen receptor alpha in cultivated articular chondrocytes from cows and bulls under certain culture conditions. Estrogen receptor alpha is detected by the use of antibody 13H2 in articular chondrocytes from cows, bulls, pigs and humans. Chondrocytes are physiologically exposed to reduced oxygen tension. In isolated articular chondrocytes from cows and bulls incubated either with 21% O2 or with 5% O2 positive cells were also found. These positive results therefore encourage testing the influence of estradiol on cultivated articular cartilage cells in these species under different culture conditions.

Aged↗
PubMed2000

Evaluation of water content by spatially resolved transverse relaxation times of human articular cartilage.

Non-invasive assessment of cartilage properties, specifically water content, could prove helpful in the diagnosis of early degenerative joint diseases. Transverse relaxation times T(2) of human articular cartilage (34 cartilage slices of three donors) were measured on a pixel-by-pixel basis in a clinical whole body MR system in vitro. In vivo feasibility to measure quantitative T(2) maps was shown for human patellar cartilage. The relaxation times of cartilage with collagen in the radial zone oriented perpendicular to the magnetic field increased from approximately 10 ms near the bone to approximately 60 ms near the articular surface. Cartilage water content of the tibial plateau and femoral condyles could be determined from the correlation with T(2) (R(2) = 0.71) with an error of approximately 2 wt.%. In vivo, directional variation would need to be considered. If confirmed in vivo, T(2) measurements could potentially serve as a non-invasive tool for the evaluation of the status and distribution of water content in articular cartilage.

Adult↗
PubMed2000

Magnetic resonance arthrography of the acetabular labrum. Macroscopic and histological correlation in 20 cadavers.

We studied the sensitivity and specificity of magnetic resonance arthrography (MRa) for the diagnosis of lesions of the acetabular labrum in 20 cadaver hips. The MRa results were compared with macroscopic and histological findings. We found that the labrum could be satisfactorily delineated by MRa and that large detachments could be identified satisfactorily. The diagnosis of small detachments and degeneration of the labrum was less reliable.

Acetabulum↗
PubMed1999

[MR arthrography of the labrum acetabulare--a radiological-anatomical correlation in 20 cadaveric hips].

PURPOSE: To investigate frequency of acetabular labral lesions in elderly hip joints, and to determine sensitivity and specificity of MR arthrography (MRa) for the detection of these abnormalities. MATERIALS AND METHODS: Twenty cadaveric hip joints were examined by MRa. For MRa, 15 ml of a solution of iodinated contrast solution (Solutrast 300) and Gd-DTPA (100:1) were injected under fluoroscopic guidance. MR imaging was performed on a 1.5 T MR scanner (Vision, Siemens; FOV 16 cm, matrix 256 x 256, fat-suppressed 3D-FLASH). Multiplanar image reconstructions were done perpendicular to the acetabulum in the oblique-coronal, oblique-axial, and radial planes. The labral specimens were examined macroscopically. RESULTS: In 12/20 hips (60%), a labral lesion was found on pathologic examination. In 7 specimens, the labrum was partially or completely detached in the weight-bearing superior region. One flap-like variant of the labrum was seen; in 4 hip joints, the labrum was degenerated (one cystic degeneration). Pathologic findings were confirmed by MRa in 8/12 specimens (sensitivity 67%). All degenerated labra were correctly diagnosed on MRa. Three small labral detachments and the flap-like variant were misinterpreted as being normal. There were no false positive findings (specificity 100%). The accuracy was 80%. Labral lesions were seen in 6/8 and in 6/12 of hips with and without osteoarthritis, respectively. CONCLUSION: MRa is well suited to delineate the acetabular labrum and to diagnose labral abnormalities. Detection of small labral detachments and anatomic variants is difficult and requires some experience. Labral lesions are correlated to osteoarthritis of the hip, but may be frequently seen in the elderly without underlying osteoarthritis.

Acetabulum↗
PubMed1999

Sonographic hip screening and early management of developmental dysplasia of the hip.

The reliability of Graf's technique in diagnosing developmental dysplasia of the hip (DDH) is investigated in this report. In a prospective study, 6,548 neonates were examined clinically and sonographically; 470 children were reexamined at least once. Sonographic alpha angles and radiographic acetabular index (AI) angles were followed up and compared. Results were as follows: 84.6% of the hips were mature; 14.3% were physiologically immature; 1.1% were dysplastic. Of the sonographically dysplastic hips, 63% were clinically normal. Neonatal sonographic hip status was affected by family history, breech delivery, birth weight, and gestational age. At follow-up, none of the primarily mature hips had worsened. Of the type IIa hips, 89% matured spontaneously, and 11% needed abduction. The 68 dysplastic hips had matured after a maximum of 80 days' abduction, with normal alpha and AI angles by the end of treatment. At 1 year, the pitch had deteriorated again in six children. Graf's sonographic technique reliably diagnoses infantile DDH. Regular orthopedic checkups are needed to detect secondary deterioration of dysplastic hips.

Birth Weight↗
PubMed1992

[The femoropatellar gliding motion during active knee stretching. Imaging using motion-triggered MR tomography].

By means of motion-triggered MRT it has been possible for the first time to demonstrate movements in the patello-femoral joint by means of MRT. Patello-femoral movement was studied during active extension of the knee between 30 degrees flexion and complete extension. The knees of 5 normal females and 7 normal males were studied together with 2 women with recurrent lateral patellar luxation. In normal women there was an average 16 degrees (10 to 18 degrees), in men an average of 12 degrees (10 to 14 degrees) of lateralisation of the patella during complete extension of the knee. In 1 patient there was 10 degrees medial displacement of the patella before extension. In 2 knees with recurrent lateral subluxation there was a 20 and 24 degrees displacement of the patella.

Adolescent↗
PubMed1991

[Hinge endoprosthesis of the knee joint. Long-term results based on the Blauth prosthesis].

Knee prostheses of the condylar or hinge type have constructional features that have both advantages and disadvantages. Both types are compromises as a result of different demands. Here we report long-term results with the Blauth prosthesis as an example of the efficiency of the hinge concept. The Blauth prosthesis is constructed according to the low-friction principle without a weight-bearing axis. Load transmission to the bone is accomplished by large interface areas. The sliding bearing of the patella is oriented perpendicular to the transverse axis of rotation. A prospective multicentric study reports on 511 prosthesis with a follow-up between 1 and 15 years. Aseptic loosenings were confirmed in 1.2% of the patients, deep infections in 3.3%. The survival analysis showed a probability of 89% that a prosthesis would not have a deep infection or loosen. A hinged knee prosthesis shows positive long-term results even compared with the condylar types if the relevant principles of construction are adequately considered.

Aged↗
PubMed1991

[CPM treatment of the shoulder joint].

Since Salter's results about experimental continuous passive motion (CPM) there are remarkable, generally positive experiences on CPM-treatment of the knee-joint. Now CPM-experiences on shoulder joints are described based on data from 150 patients during the last six years. Three types of motorized CPM-machines are presented for the treatment of the shoulder joint. At the present time they are components of the so-called "Artromot-System." Indications and applications of the CPM-devices are described. Patients are accepting the new way of treatment promptly, because they could apply the devices during the early postoperative period for hours in a selected range of motion, causing no pain. The duration of the CPM-treatment should be two to four hours a day. As shown by Salter's experimental studies the continuous passive motion enhances the metabolism of a joint, improves the resorption of effusions, and may prevent joint stiffness as well as secondary arthrosis. CPM-treatment can especially be prolonged for outpatients; thus CPM treatment can contribute to shorten the hospital stay and the time of treatment in general showing an economic factor.

Humans↗