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Biomedical subjects

E Horii

Publications and source records attributed to E Horii.

At least 37 records · Page 2Linked to original sources

Scaphoid fracture as a "puncher's fracture".

We investigated 18 scaphoid fractures induced by punching. The wrist position while punching was neutral to slight palmar flexion. We postulated that the mechanism of the fracture was caused by the concentration of the external force to the second metacarpus. The forces are then dispersed to the trapezium and trapezoid, which produces shear stress at the waist of the scaphoid. In spite of the differences in mechanism, the location of the fracture was similar to fractured scaphoids caused by wrist extension injuries. Regardless of the wrist positions, the carpal scaphoid is most vulnerable to fracture due to its characteristic morphology.

Adolescent↗

Changes in carpal alignment following radial osteotomy for Kienböck's disease.

Changes in carpal alignment following radial osteotomy were studied in 30 patients with Kienböck's disease. The carpal height ratio and carpal-ulnar distance ratio were significantly less in wrists with Kienböck's disease than unaffected wrists. This observation implies proximal-ulnar translation of the capitate. In addition, the lunate-covering ratio increased significantly, reflecting radial translation of the lunate. Radial osteotomy corrected ulnar translation of the capitate and increased the radial translation of the lunate, thus increasing the lunate-covering ratio. The increased lunate-covering ratio is believed to increase the area of distribution of the axial load through the lunate by increasing the contact area with the radius. The satisfactory clinical outcome of radial osteotomy is believed to be due to this effect on carpal alignment.

Adolescent↗

Scaphoid non-union: factors affecting the functional outcome of open reduction and wedge grafting with Herbert screw fixation.

50 patients with scaphoid non-union were treated by open reduction, anterior wedge bone grafting and internal fixation using the Herbert screw. Intra-operative image intensifier control enabled us to insert the screw into the scaphoid accurately. An excellent or good functional outcome was less likely when more than 5 years had elapsed since injury, the non-union was in the proximal third, when sclerosis of the proximal fragment was present, and when reduction of carpal and scaphoid deformity was unsatisfactory. These four factors are believed to be the primary determinants affecting the functional results of the surgical treatment of scaphoid non-union, even when bony union is achieved.

Adolescent↗

The aetiological significance of work-load in the development of osteoarthritis of the distal interphalangeal joint.

The incidence of Heberden's nodes was determined in three groups of Japanese women with different occupations to investigate the role of work-load in their pathogenesis. School cooks (n = 260), each of whom prepared 150 to 450 lunches daily, pre-school cooks (n = 222), each of whom prepared 30 to 80 lunches daily, and municipal employees (n = 298) underwent physical examination and X-ray of the hand if pathology was present. The incidence of Heberden's nodes and X-ray incidence of osteoarthritis was 19.2% and 13.5%, 8.6% and 5.4%, 5.9% and 2.0% among school cooks, pre-school cooks and municipal workers, respectively. The incidence of Heberden's nodes and osteoarthritis was significantly higher among school cooks. These findings support the concept that work-load is an aetiological factor in the pathogenesis of Heberden's nodes and also support Radin's hypothesis that women's daily work pattern explains the increased incidence of DIP joint osteoarthritis in women.

Adult↗

Premature closure of the distal radial physis.

Two cases of fracture of the radius treated by pinning resulted in severe wrist joint deformity due to premature closure of the epiphysial growth plate. Inappropriate pinning through the physis damaged the growth plate in both cases. They were treated by bone bridge resection with free fat interposition. The bone bar resection was effective in correcting the wrist joint deformity, and bone growth was expected without bone grafting.

Bone Wires↗

Excursion of prime wrist tendons.

To allow continuous and simultaneous measurements of tendon excursion and joint rotation angles, we developed a system using an electric potentiometer and an electromagnetic tracking device. Instantaneous moment arms of each tendon could then be calculated on the basis of the slope of the curve between tendon excursion and joint angular displacement. Five prime wrist motor tendons were studied on freshly frozen cadavers. Calculated tendon moment arms were found to be consistent throughout a full range of flexion-extension wrist motion and radioulnar deviation and corresponded closely to the anatomic location and orientation of the tendons. The flexor carpi ulnaris tendon provided the largest moment contribution to the wrist joint. Forearm rotation did not affect the function of the wrist tendon except for the extensor carpi ulnaris. During flexion-extension motion, the excursion of the extensor carpi ulnaris decreased significantly from 10 to 4 mm, with the forearm in neutral and pronated positions. During radioulnar deviation, the excursion of the extensor carpi ulnaris increased from 14 to 17 mm with the forearm in supinated and pronated positions.

Aged↗

Biomechanical analysis of radial wedge osteotomy for the treatment of Kienböck's disease.

Biomechanical analysis of force transmission through the lunate was performed with the use of a two-dimensional mathematical model to evaluate the usefulness of radial wedge osteotomy, a procedure that decreases radial inclination, in the treatment of Kienböck's disease. The forces acting on the carpal bones were compared before and after radial wedge osteotomy in 29 patients with Kienböck's disease. The average osteotomy angle was 9.6 degrees. The total force through the lunocapitate joint at the midcarpal level was decreased by 23%, while the total force through the radiolunate and ulnolunate joints at the radioulnocarpal level was decreased by 10% and 36%, respectively. These changes correlated directly with the osteotomy angle and demonstrate decompression of the lunate by radial wedge osteotomy.

Biomechanical Phenomena↗

Stability and constraint of the proximal interphalangeal joint.

The kinematics of the intact proximal interphalangeal joint of 12 fresh cadaver index fingers were measured by means of an electromagnetic tracking system. The specimens were then randomly divided into two groups for ligament sectioning in two different sequences and for testing under lateral stress. Lateral stress of the intact proximal interphalangeal joints produced an average of 5 degrees of adduction and 9 degrees of supination motion throughout the arc of flexion/extension. Maximum lateral angulation was 15 degrees under 1 kg of force (30 N cm) applied at the distal end of the middle phalanx. Joint angulation increased to 20 degrees after total sectioning of the collateral ligament. Joint laxity was greatly reduced in full extension, in full flexion, and when the muscles were loaded. The proximal interphalangeal joint remained stable when one half of the collateral ligament was left intact. The results indicate that lateral stability of the proximal interphalangeal joint is provided primarily by the collateral ligament. When the lateral stress test is normal in proximal interphalangeal joint extension, an additional test in 20 to 30 degrees of flexion should be considered to avoid a false-negative result. Angulation greater than 20 degrees is abnormal and indicates a loss of collateral ligament integrity.

Electromagnetic Phenomena↗

[Posterolateral rotatory instability of the elbow--a case report and anatomical study of the lateral collateral ligament].

A 20-year-old woman was referred to our clinic complaining of recurrent subluxation of her right elbow. A posterolateral rotatory instability test revealed that she had insufficiency of the lateral collateral ligament. She was surgically treated; the ligament was reconstructed by using the palmaris longus tendon. A year after operation, she had no pain in her elbow, and regained full range of elbow motion. The function of the lateral collateral ligament is often overlooked. We, therefore, dissected 24 elbow joints and studied anatomically in order to confirm the origin and insertion of the lateral collateral ligament. The ligament originates from the lateral epicondyle, and runs distally in fan shape. It further inserts partly to the annular ligament and partly to the supinator crest. After complete sectioning of the ligament, the forearm was fixed in supination, then flexed with valgus moment. This maneuver elicited subluxation of the radio-humeral joint, which was similar to what we observed in the clinical case. From these observations, we have concluded that the ligament is important for stability of elbow joint as well as the medial collateral ligament.

Adult↗

The Sauvé-Kapandji procedure for chronic dislocation of the distal radio-ulnar joint with destruction of the articular surface.

The Sauvé-Kapandji procedure has been performed in 15 non-rheumatoid patients with chronic distal radio-ulnar joint dislocation accompanied by joint damage or deformity. The clinical results were favourable; wrist pain improved in all patients, wrist flexion-extension was increased by more than 10 degrees in nine patients, grip strength of at least 80% of the contralateral wrist was achieved in 11 patients, and forearm rotation was more than 150 degrees in 12 patients. However, X-ray examination revealed an unstable proximal ulnar stump and radio-ulnar convergence in all patients similar to that associated with the Darrach procedure. Although the Sauvé-Kapandji procedure can preserve ulnar support of the wrist and is believed to yield more satisfactory results than the Darrach procedure, its extensive use is not recommended for non-rheumatoid distal radio-ulnar joint disorders, but it is recommended for chronic distal radio-ulnar joint dislocation with articular injury or deformity.

Adult↗

The relationship between wrist position, grasp size, and grip strength.

In the first part of this study, the position assumed by a normal wrist during unconstrained maximal grip and the relationship between wrist position and grip strength were investigated in 20 healthy subjects. Grip strength and wrist position were recorded in the self-selected position and then again while the subjects voluntarily deviated the wrist randomly into flexion, extension, or radial or ulnar deviation of 10 to 15 degrees. The self-selected position was 35 degrees of extension and 7 degrees of ulnar deviation. Grip strength was significantly less in any position of deviation from this self-selected position, even after accounting for fatigue. With the wrist in only 15 degrees of extension or in neutral radio-ulnar deviation, grip strength was reduced to two thirds to three fourths of normal. Sex did not affect wrist position. The dominant wrists were within 5 degrees of the nondominant ones but were relatively less extended and in more ulnar deviation. Grip strength is significantly reduced when wrist position deviates from this self-selected optimum position. In the second part of the study, the effect of grasp size on this self-selected position was studied in 21 subjects. The degree of wrist extension was inversely and linearly related to how large a setting on the Jamar dynamometer was used. This was true regardless of hand size, although the effect was more significant for smaller hands. Radial and ulnar deviations were not affected by handle position. A minimum of 25 degrees of wrist extension was required for optimum grip strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Comparative flexor tendon excursion after passive mobilization: an in vitro study.

Two experimental studies were conducted to investigate flexor tendon excursions. In the first study, tendon excursions due to passive joint motion in various loading condition were evaluated. In the second study, the efficacy of a new technique that used synergistic wrist motion (S-splint) was compared with the traditional dorsal splinting methods: the Kleinert splint (K-splint) and the Brooke Army Hospital/Walter Reed modified Kleinert splint with a palmar bar (P-splint). The results of these studies question the anticipated tendon excursion associated with postoperative splinting. They demonstrated that the measured tendon excursion under a condition of low tendon tension was almost half that of theoretically predicted values. In zone II, the magnitude of excursion introduced by the three mobilization methods were in descending order: S-splint, P-splint, K-splint (p less than 0.05). Differential tendon excursion between the flexor digitorum profundus and the flexor digitorum superficialis had a mean value of 3 mm and was not significantly different among the three methods. Passive proximal interphalangeal joint motion was the most effective means of providing increased amplitude of tendon gliding in zone II. Passive distal interphalangeal joint motion did not increase excursion in zone II as much as had been predicted.

Cadaver↗

Force distribution across wrist joint: application of pressure-sensitive conductive rubber.

A new pressure-sensitive conductive rubber sensor was used for investigation of the pressure distribution through the radio-ulno-carpal joint. Twelve of these transducers were placed in the radio-ulno-carpal joint. Pressure was measured in seven different wrist positions under loads incrementally increasing from 0 to 12 kg. Half of the sensors showed less than 0.5 MPa, even at maximum load, while a high-pressure area was located palmary in each fossa. The peak pressure measured in the wrist neutral position was 2.4 MPa on the scaphoid fossa, 1.5 MPa on the lunate fossa, and 1.1 MPa on the triangular fibrocartilage with a 10 kg load. The peak pressure ratio between the scaphoid and the lunate was 1.7 in the neutral wrist position. This increased in radial deviation to 2.9 and decreased in ulnar deviation to 0.8. The force-transmission ratio was 50% through the scaphoid fossa, 35% through the lunate fossa, and 15% through the triangular fibrocartilage in the neutral position. The advantage of this sensor is that it is thin and flexible and provides reliable reproducible quasi-instantaneous measurements.

Biophysical Phenomena↗

Analysis of scaphoid fracture displacement by three-dimensional computed tomography.

Scaphoid fracture displacement was studied in twenty-five patients using three-dimensional computed tomography. Fracture displacement was more readily detected and distinct in three-dimensional computed tomography images than in plain radiography. Two different types of offset of the distal fragment with respect to the proximal fragment are described on three dimensional computed tomography; volar type and dorsal type. In the volar type, the distal fragment overhung in the volar direction relative to the proximal fragment and was frequently accompanied by humpback deformity and axial rotation. In the dorsal type, the distal fragment slipped dorsal on the proximal fragment and was commonly accompanied by humpback deformity. The volar type had a transverse or vertical fracture line on both the volar and dorsal surfaces of the scaphoid, while the dorsal type had a horizontal fracture line. The volar type was frequently found when the fracture was distal, whereas the dorsal type was noted more frequently for proximally located fracture.

Adolescent↗

A kinematic study of luno-triquetral dissociations.

An analysis of carpal motion after sectioning the ligamentous support of the luno-triquetral joints was done by use of stereoradiographic methods. The ligaments were sectioned in two stages. In stage I, a complete sectioning of both the dorsal and palmar luno-triquetral ligaments and the interosseous membrane was done. Stage II consisted of further sectioning of both the dorsal radio-triquetral and dorsal scapho-triquetral ligaments. After both stage I and stage II ligament sectioning, all of the intercarpal joints exhibited altered kinematics. The changes were especially marked at the luno-triquetral joint where motion was increased in all planes of wrist motion. The essential lesion in producing a static palmar flexed intercalated segment instability was division of the dorsal radio-triquetral and dorsal scapho-triquetral ligaments in association with the luno-triquetral ligaments and interosseous membrane sectioning.

Cadaver↗

The cubital tunnel and ulnar neuropathy.

The anatomy of the cubital tunnel and its relationship to ulnar nerve compression is not well documented. In 27 cadaver elbows the proximal edge of the roof of the cubital tunnel was formed by a fibrous band that we call the cubital tunnel retinaculum (CTR). The band is about 4 mm wide, extending from the medial epicondyle to the olecranon, and perpendicular to the flexor carpi ulnaris aponeurosis. Variations in the CTR were classified into four types. In type 0 (n = 1) the CTR was absent. In type Ia (n = 17), the retinaculum was lax in extension and taut in full flexion. In type Ib (n = 6) it was tight in positions short of full flexion (90 degrees to 120 degrees). In type II (n = 3) it was replaced by a muscle, the anconeus epitrochlearis. The CTR appears to be a remnant of the anconeus epitrochlearis muscle and its function is to hold the ulnar nerve in position. Variations in the anatomy of the CTR may explain certain types of ulnar neuropathy. Its absence (type 0 CTR) permits ulnar nerve displacement. Type Ia is normal and does not cause ulnar neuropathy. Type Ib can cause dynamic nerve compression with elbow flexion. Type II may be associated with static compression due to the bulk of the anconeus epitrochlearis muscle.

Biomechanical Phenomena↗

Excessive radial shortening in Kienböck's disease.

Two patients with Kienböck's disease who had been treated by radial shortening developed ulnar wrist pain post-operatively due to excessive radial shortening. In both cases, ulnar shortening was required to improve symptoms and function. Excessive radial shortening can cause ulnar wrist pain and compromise the improvement of grip strength and range of motion of the wrist.

Adult↗