Biomedical subjects

K Herrlin

Publications and source records attributed to K Herrlin.

24 records · Page 2Linked to original sources

PubMedDate not supplied

Trochanteric fractures. Classification and mechanical stability in McLaughlin, Ender and Richard osteosynthesis.

Four hundred and thirty trochanteric fractures operated upon with McLaughlin, Ender or Richard's osteosynthesis were divided into 6 different types based on their radiographic appearance before and immediately after reposition with special reference to the medial cortical support. A significant correlation was found between the fracture type and subsequent mechanical complications where types 1 and 2 gave less, and types 4 and 5 more complications. A comparison of the various osteosyntheses showed that Richard's had significantly fewer complications than either the Ender or McLaughlin types. For Richard's osteosynthesis alone no correlation to fracture type could be made because of the small number of complications in this group.

Bone Nails↗

PubMedDate not supplied

Digital radiography of the spine, large bones and joints using stimulable phosphor. Early clinical experience.

The value of digital radiography in musculoskeletal disorders was investigated by assessing its ability to depict anatomic structures and common radiologic features as compared with the conventional film-screen combination. The digital image that was frequency modified was superior to conventional films in delineating soft tissue structures and for areas with large attenuation differences. The conventional film-screen system was superior in depicting small anatomic structures and in identifying the zone close to prostheses. This was explained by the high spatial resolution of the conventional film system and the disturbing halo effect around the prosthesis seen with digital images. The halo effect is an overshoot caused by the unsharp masking operator, which was in this series not changed for individual examinations. The exposure (radiation dose) could be reduced to 50 per cent using the digital system, without any loss of information.

Arthrography↗

PubMedDate not supplied

Comparison of two- and three-dimensional methods for assessment of orientation of the total hip prosthesis.

A comparison of two- and three-dimensional methods for the determination of the orientation of total hip prostheses was made in a group of 57 patients. The acetabular inclination and the collum-diaphyseal angle measured on a.p. projections (2-D) were adequate in most cases for assessing how vertically the prosthetic component was inserted, but in individual cases with a high degree of version these measurements could be misleading. Anteversion measured in the transverse plane (2-D) was more sensitive to errors than planar anteversion measured as a rotation around the longest diameter of the ellipsoid projection of the acetabular opening, but it gave a rough estimate of the relation of the prosthetic components. Determination of the spatial (3-D) orientation of the components provides a precise estimate of the component relations.

Acetabulum↗

PubMedDate not supplied

Femoral anteversion and restricted range of motion in total hip prostheses.

Impingement of the neck of the stem on to the rim of the socket may cause dislocation of the total hip prosthesis. The role of femoral anteversion in the occurrence of such impingement was analyzed in a clinical material of total hip prostheses with and without dislocation. A low femoral anteversion was linked to a clinically relevant reduction of the range of motion due to impingement and dominated in the group with dislocations. Impingement is minimized by inserting the femoral component in 10 degrees to 20 degrees of anteversion.

Aged↗

PubMedDate not supplied

Range of motion caused by design of the total hip prosthesis.

In a clinical material of total hip prostheses, a study was performed of the range of femoral motion until impingement occurred between the neck of the femoral stem and the rim of the acetabular socket. The results were compared with the physiologic range of motion, and the clinically relevant motion restriction was measured. Restriction was most common in flexion. There was a correlation between the prosthetic design and the restriction due to impingement.

Aged↗

PubMedDate not supplied

Position, orientation and component interaction in dislocation of the total hip prosthesis.

The position, orientation in space and interaction of prosthetic components was determined in 15 patients with known episodes of dislocation after total hip replacement. The same calculations were performed in a reference group of 44 patients without dislocation. In the group with dislocations, there was a significantly decreased femoral anteversion, and a decreased femoral flexion permitted by the prosthetic components. There were no further significant differences of clinical relevance between the groups concerning all other examined parameters of component position, orientation and interaction. It is concluded that the decreased range of flexion, caused by impingement of the prosthetic components with ensuing leverage effect is one cause of dislocation.

Aged↗