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J Ovesen

Publications and source records attributed to J Ovesen.

At least 37 records · Page 2Linked to original sources
PubMed1987

The stability of the elbow following excision of the radial head and transection of the annular ligament. An experimental study.

The stabilizing role of the lateral ligament complex and the radial head were investigated in ten osteoligamentous elbow preparations. The annular ligament was the prime stabilizer of the lateral aspect of the elbow. Transection of the annular ligament caused maximal varus and external rotatory instability of 13.7 degrees and 32.8 degrees respectively, with an elbow flexion about 70 degrees. Isolated excision of the radial head caused slight varus and external rotatory instability of 4.8 degrees and 10.4 degrees respectively, with an elbow flexion about 40 degrees. The lateral collateral ligament had only a minor stabilizing function of the elbow. The stability of the elbow after excision of the radial head may be improved by proper preservation of the annular ligament.

Elbow Joint↗
PubMed1987

Transposition of coracoacromial ligament to humerus in treatment of vertical shoulder joint instability. Clinical applicability of experimental technique.

Treatment of experimental distal subluxation in the shoulder joint was achieved by transposition of the coracoacromial ligament and its bony attachment from the acromion to the lesser tuberosity of the humerus. This transposition also reduced external rotation in the first 40 degrees of abduction. The method, which was applied in two clinical cases of distal subluxation, proves reasonable from a biomechanical point of view and yields satisfactory primary clinical results.

Acromion↗
PubMed1987

Experimental elbow instability after transection of the medial collateral ligament.

In 12 osteoligamentous autopsy elbow preparations, the stability of the elbow was independent of the collateral ligament with flexion of less than 20 degrees and greater than 120 degrees. The anterior part of the collateral medial ligament was the prime stabilizer of the elbow in this range of motion, i.e., the flexion range of function. The maximum valgus and internal rotatory instability after transection of the medial collateral ligament, 20.2 degrees and 21.0 degrees, respectively, were found at elbow flexions from 60 degrees to 70 degrees. Selective repair or reconstruction of the anterior part of the elbow medial collateral ligament may prove to be effective in the treatment of acute or chronic elbow instability.

Biomechanical Phenomena↗
PubMed1986

Lesions in different types of anterior glenohumeral joint dislocation. An experimental study.

Three different kinds of anterior shoulder joint dislocation were studied in an experimental setup including 15 shoulder joint specimens. Lesion to the anterior-inferior part of the capsule was the most frequent finding in anterior dislocation. In anterior-superior dislocation lesions to the anterior-inferior part of the capsule and the posterior part of the cuff were equally prominent. Anterior-inferior dislocation was associated with lesions to all capsular structures including the glenohumeral ligament and both the anterior and posterior part of the cuff. From a clinical point of view, the study indicates that in some types of anterior dislocation a severe lesion of the posterior part of the capsule and cuff must also be considered.

Humans↗
PubMed1986

Anterior and posterior shoulder instability. A cadaver study.

In a cadaver study of 10 glenohumeral joint specimens, the anterior and posterior displacement of the humeral head was recorded after cutting parts of the rotator cuff and capsular structures applying a constant force to the humerus. The posterior structures were important for anterior stability in the first 40 degrees of abduction. Anterior subluxation was changed to luxation in the first half of abduction, but only after lesions to the anterior part of the rotator cuff and upper half of the anterior capsule. For posterior displacement, the posterior part of the rotator cuff was found significant from 0-90 degrees of abduction, and the posterior capsule between 40 degrees and 90 degrees of abduction. The anterior part of the rotator cuff and the upper part of the anterior capsule were essential in the first 40 degrees of abduction. Cutting the capsular structures only, we found that the entire anterior capsule resisted anterior displacement for 70-90 degrees of abduction, and the entire posterior capsule from 50-90 degrees of abduction. For posterior displacement, the entire posterior capsule was important from 60 to 90 degrees of abduction. Clinically, a large lesion to the posterior structures seems to be essential for any major anterior displacement, and posterior displacement leading to subluxation only seems possible in connection with a major anterior injury.

Biomechanical Phenomena↗
PubMed1986

Posterior instability of the shoulder. A cadaver study.

In a cadaver study of 15 shoulder specimens, the internal rotation of the joint was measured applying a constant internal torque of 1.5 Nm to the humerus. The specimens were suspended with the medial border of the scapula in vertical position. A lever fixed to the humerus was fitted with strain gauges for measurement of internal torque and sensors for measurement of internal rotation at different degrees of abduction from 0-90 degrees. Cutting the teres minor and infraspinatus muscle tendons increased internal rotation in the first 40 degrees of abduction. Internal rotation was further increased in this range by cutting also the proximal half of the posterior capsule. Lesion to the posterior capsular structures alone increased internal rotation from 40 degrees of abduction. In conclusion, among the posterior structures of the shoulder joint, the teres minor and the infraspinatus muscle tendons stabilize the joint for internal rotation in the first half of abduction, and the lower half of the capsule in the last part.

Biomechanical Phenomena↗
PubMed1986

Posterior shoulder dislocation. Muscle and capsular lesions in cadaver experiments.

In 10 cadaver shoulders, a posterior subspinous dislocation of the humeral head was provoked. All specimens showed total rupture of the posterior capsule and teres minor muscle, in most cases together with partial lesion in the infraspinatus muscle. In the majority of the specimens, lesions were also seen in the lower part of the subscapular muscle and in the proximal part of the anterior capsule.

Cadaver↗
PubMed1985

Knee-joint arthroplasty according to Stanmore. A clinical and radiographic follow-up.

Of a total of 56 knee arthroplasties according to Stanmore, a clinical and radiographic follow-up was performed on 38, with mean follow-ups of 36 months for rheumatoid arthritis and 34 months for osteoarthritis. Early complications occurred in nine of 56 cases. Clinically satisfactory results were obtained in 71%. Radiolucent zones of 3 mm or more were found to be associated with clinically verified loosening.

Aged↗
PubMed1985

The posterior cruciate ligament and rotatory knee instability. An experimental study.

The importance of the posterior cruciate ligament in relation to valgus-varus and axial rotatory stability in the knee joint was investigated. Mobility patterns were drawn from 20 osteoligamentous preparations after successive transection of the posterior cruciate ligament (PCL), the medial and lateral collateral ligaments, and the posterior joint capsule. The knee joint remained grossly stable after isolated transection of the PCL, and further cutting of either one of the collateral ligaments or of the posterior capsule yielded no greater instability than one should expect from isolated cutting of each of these structures. The posterior cruciate ligament was the stabilizing factor in flexion and external rotation after injury to the lateral collateral ligament and the posterolateral capsule, and it restricted internal rotation after cutting of the medial cruciate ligament and the posteromedial capsule. Valgus instability was markedly increased during the whole range of movement when PCL was included in injury to the medial compartment ligaments, and when included in a lateral compartment injury a further varus instability was found, though only in the flexed or semiflexed knee. No hyperextension could be demonstrated after these injuries.

Biomechanical Phenomena↗
PubMed1985

Experimental distal subluxation in the glenohumeral joint.

In an experimental set-up including ten shoulder specimens, increments in the acromiohumeral distance (the subacromial space) were measured on an X-ray radioscope after the vertical stabilizing structures of the glenohumeral joint had been cut. It was found that when only the supraspinatus tendons were cut, the acromiohumeral space only increased by a few millimeters. When first the coracohumeral ligament and then the proximal one-third of the anterior capsule were cut, the acromiohumeral distance was doubled in each case. Distal subluxation did not occur when only the anterior capsule was cut. When the coracohumeral ligament was also cut, the acromiohumeral distance was more than doubled. It is concluded that the most important structures in the pathogenesis of distal subluxation are first the coracohumeral ligament and then the proximal part of the glenohumeral capsule.

Acromion↗
PubMed1985

Prosthesis position in shoulder arthroplasty. A cadaver study of the humeral component.

In six cadaver shoulder joints, the external rotation was measured applying a constant external torque to the humerus before and after insertion of a non-constrained shoulder joint prosthesis at different degrees of retroversion. At 35-45 degrees of retroversion there was no difference between the external rotation of the inserted prosthesis and the external rotation of the joint before arthroplasty.

Biomechanical Phenomena↗
PubMed1985

Stability of the shoulder joint. Cadaver study of stabilizing structures.

In 10 cadaver shoulder joints, the increments in external rotation were measured after successive cutting of the anterior stabilizing structures while a constant external torque was applied to the humerus, abducted in the scapula plane. The subscapularis muscle prevented anterior subluxation in the lower range of abduction. As abduction increased, the lower part of the capsule was the most important stabilizing structure. The findings suggest that it may be possible to perform more selective repairs in the treatment of recurrent anterior instability.

Biomechanical Phenomena↗