Yoshiaki Morito

NON-TRAUMATIC PARALYSIS OF THE POSTERIOR INTEROSSEOUS NERVE

We treated 31 patients with non-traumatic paralysis of the posterior interosseous nerve over 15 years. There were 10 men and 21 women of mean age 40.3 years (17 to 71). Six were managed conservatively, and 25 by operation. In 14 patients entrapment occurred at the supinator, including three who had double compression at both the entrance and exit from the muscle. In four it was caused by a ganglion, in one by a lipoma, in one by a dislocated radial head and in two by a marked constriction in the nerve of unknown cause. The remaining three patients were retrospectively diagnosed as having neuralgic amyotrophy, the only observable change at operation being slight oedema of the nerve. Paralysis recovered in 24 out of the 25 patients at between 2 to 18 months (mean 5.6) after operation, and the one failure was treated later by tendon transfer.

Anatomic and histologic studies of lateral collateral ligament complex of the elbow joint.

We studied the gross and histologic anatomic characteristics of the lateral collateral ligament complex of the elbow joint from 15 cadavers to demonstrate its cross-sectional anatomy. The lateral ulnar collateral ligament adheres closely to the supinator, the extensor muscles, its intermuscular fascia, and the anconeus muscle and lies posterior to the radial collateral ligament. The lateral ulnar collateral ligament itself was identified with microscopy as a slender, poor structure consisting of the thick area of the posterolateral capsuloligamentous layer and a poorer structure than the anterior bundle of the medial collateral ligament as the primary stabilizer of the elbow joint. We believe that the lateral ulnar collateral ligament contributes to rather than is a major constraint to the posterolateral rotatory instability as part of the lateral collateral ligament complex with the surrounding tissues.

Fractures of the Base of the Middle Phalanx of the Finger

We classified fractures of the base of the middle phalanx into five types: 1) single palmar fragment; 2) single dorsal fragment; 3) two main fragments; 4) not involving the articular surface, including epiphyseal separation in children; and 5) all others. Types 1 and 2 were subclassified into avulsion, split and split-depression. Surgery is recommended for unstable type-1 avulsion fractures, type-2 avulsions which may develop buttonhole deformities, and all fractures which displace articular cartilage surfaces. Long-term follow-up showed that surgical treatment which produced good stability and congruity gave good results. These should be the primary aims of treatment.

The Central Slip Attachment Fracture

Eight displaced central slip attachment fractures were treated by open reduction and internal fixation to avoid boutonnière deformity, to reduce the fracture anatomically and to allow early mobilization of the joint. This injury should be recognized as a disruption of the dynamic extensor mechanism associated with an intraarticular fracture, fracture-dislocation or soft tissue injury of the PIP joint. We have grouped central slip attachment fractures into three types according to the mechanism of injury, with suggested methods of treatment.

The Galeazzi-Equivalent Lesion in Children Revisited

A fracture at the medial end of the distal third of the radius with an epiphyseal separation of the distal ulna in a 16-year-old boy is described. This injury, known as the Galeazzi-equivalent lesion in children, is characterized by complete distal ulnar epiphyseal separation without rupture of the distal ligamentous stabilizing system between the radius and ulna, which includes the triangular fibrocartilage complex, interosseous ligaments and periosteal tube of the ulnar. The Galeazzi fracture-dislocation and the Galeazzi-equivalent lesion appear to be completely dissimilar in their pathological anatomy. We suggest calling the latter a “pseudo-Galeazzi injury”.

FRACTURES OF THE BASE OF THE MIDDLE PHALANX OF THE FINGER

We classified fractures of the base of the middle phalanx into five types: 1) single palmar fragment; 2) single dorsal fragment; 3) two main fragments; 4) not involving the articular surface, including epiphyseal separation in children; and 5) all others. Types 1 and 2 were subclassified into avulsion, split and split-depression. Surgery is recommended for unstable type-1 avulsion fractures, type-2 avulsions which may develop buttonhole deformities, and all fractures which displace articular cartilage surfaces. Long-term follow-up showed that surgical treatment which produced good stability and congruity gave good results. These should be the primary aims of treatment.

Acute posterolateral rotatory subluxation of the elbow joint. A case report.

The elbow joint has become increasingly recognized as a very important joint for all sports activities. Players in some sports cannot compete at all with an unstable elbow due to ligament injuries. Thus, professional sports players and heavy laborers, as in our case, should find the excellent results of primary ligament repair preferable. This technique is less invasive than secondary ligament reconstruction and can result primarily in an accurate, stable elbow with full range of motion for mobilizing the joint and muscles at an early stage.