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Biomedical subjects

R Johner

Publications and source records attributed to R Johner.

At least 19 recordsLinked to original sources
PubMed2000

The point of view of the clinician: a prospective study of the mechanism of accidents and the morphology of tibial and fibular shaft fractures.

In a prospective study of 210 tibial shaft fractures, the accident mechanisms and the resultant fracture morphologies were analyzed. 86 fractures occurred due to indirect impact. The fracture morphology in this group consisted of short and long spiral fractures resulting from rotational injuries complicated by anterior torsion butterfly fragments if the person fell forward, posterior torsion butterfly fragments if they fell backwards and complicated by multiple torsion butterfly fragments if it was a high velocity injury. 124 fractures occurred due to direct impact. The fracture morphology in this group consisted of transverse, oblique segmental or crush fractures, complicated by one or more butterfly fragments due to bending, the injury depending on whether it was pure, one-point, three-point, or four-point-bending and on additional axial loading and velocity. In the indirect impact group, there were a few soft tissue injuries and fibular fractures at a different level to the tibial fracture. In the direct group, a large number of soft tissue injuries and fibular fractures at the level of impact were found.

Accidents↗
PubMed2000

The epidemiology of diaphyseal fractures of the tibia.

AO Documentation collected reports of nearly five thousand diaphyseal tibial fractures occurring in the 1980s. The following conclusions can be drawn: i. The number of fractures affecting men is twice that affecting women. ii. These fractures occurred mainly in younger people (under 40 years of age) and no increase occurred in elderly people. iii. Most bending fractures occurred in young men (20-30 yrs) and the torsion fractures affected men and women of about 40 equally. iv. The number of simple fractures (type A) is about the same as for fractures with one fragment (type B).

Adolescent↗
PubMed2000

The mechanical strength of bones in torsion application to human tibiae.

How strong is a long bone in torsion? The principle of mechanical engineering of torsion on a beam is applied to the cylindrical tube model of a bone. The deformation and the strength of the tube are calculated. The calculated strength is about twice that of a real, not circular bone (human tibia) with the same cross-sectional area.

Biomechanical Phenomena↗
PubMed1989

[Distal radius fracture; fixation using Kirschner wire or only a cast? A retrospective comparative study].

56 distal radius fractures were followed for a median period of 54 months (31-88 months) following the accident. Conservative treatment (immobilisation in a plaster alone) was compared to percutaneous K-wire fixation. The two groups of patients were matched in regard to type of fracture, age (+/- 5 years) and sex. The functional end result was assessed according to the scoring system of Gartland/Werley, which was modified by Solgaard. The operative treatment modality showed better functional end results, especially for intraarticular fractures, when compared to the conservatively treated fractures.

Aged↗
PubMed1983

Classification of tibial shaft fractures and correlation with results after rigid internal fixation.

A classification of tibial shaft fractures based on etiology, morphology, and clinical features is documented in a series of 291 fractures treated by AO/ASIF rigid internal fixation. The fractures were placed in nine main fracture groups, each with three subgroups according to location in the proximal, middle, or distal segment of the shaft. Group A includes all simple fractures, and Group B includes fractures with butterfly fragments and cortical contact between the main proximal and distal fragments. In Group C there is no such contact. For all degrees of comminution, Group 1 includes the spiral fractures and Groups 2 and 3 the nonspiral bending fractures. Group C2 contains segmental and Group C3 crush and high-velocity projectile fractures.

Adolescent↗
PubMed1983

Rigidity of pure lag-screw fixation as a function of screw inclination in an in vitro spiral osteotomy.

The rigidity of lag-screw fixation of experimental tibial fractures was tested in 27 anatomic specimens. Spiral osteotomies with a 60 degree angle of ascent were produced using a Gigli saw. Three screws with an axial force of 100 kp were inserted at 90 degree, 80 degree, or 70 degree of longitudinal inclination. The 70 degree group was stable in axial compression up to 88 kp and the 80 degree group up to 151 kp. Rigidity in bending was 50% in the 70 degree and 80 degree groups and 27% in the 90 degree group, while rigidity in torsion was 20% as compared with the intact bone. Screws tightened with 50 kp and 150 kp showed increased rigidity as axial screw force increased. There were only small gains in torsion and bending, whereas there was a 200% gain in compression. This confirms the view that in long spiral fractures of the tibia three lag screws alone can maintain sufficient stability to permit early limb mobility. If the screws are inserted perpendicular to the bone, the high resistance to axial compression may permit early partial weight-bearing.

Biomechanical Phenomena↗
PubMed1981

[The primary reconstruction of the skin of the lower extremity].

Regarding the usual procedures for closure of defects of the lower extremity, the author prefers the primary procedure, if possible. Skin closure should be achieved by scarification. In cases with larger defects, the cross leg flap procedure is the way of treatment.

Humans↗
PubMed1979

[The combination of fractures of the lower extremity and lesion of the posterior cruciate ligament].

In 400 fractures of the upper and lower leg, 7 patients had an additional lesion of the posterior cruciate ligament. This combination occurs in people, who had a high energy frontal impact in the sitting position. The ligamenteous injury is often overlooked because of multiple injuries and difficulty in examination of a knee joint on a fractured leg. In high velocity injuries of the lower extremity, knee and hip joint injuries must not be overlooked. The diagnosis of knee injury can be made by inspection and palpation of a joint effusion and by a knee joint X-ray, which shows an avulsion fracture of the dorsal tibial spine. Repair is recommended within the first 3 weeks if possible. Later, scarring in the subluxed position and osteoporosis of the fragment will make a reconstruction very difficult.

Adult↗