Bony Mallet Thumb Treated With the Ishiguro Extension Block Technique: A Case Report.

A bony mallet thumb is an extremely rare injury. An 82-year-old man fell from a standing height and injured his right thumb. Imaging examinations revealed a rare intra-articular fracture at the dorsal side of the base of the distal phalanx of the thumb called the bony mallet thumb. Conservative treatment was adopted initially; however, surgery was deemed necessary because of the redislocation of the bone fragment. Thus, the Ishiguro extension block technique was used, and three months later, satisfactory thumb function was achieved. The Ishiguro technique is a relatively simple procedure often performed for bony mallet fingers. The current case indicated that it can also be used to treat cases of bony mallet thumbs successfully.

An uncommon midfoot injury, naviculocuneiform and calcaneocuboid fracture dislocation: a case report.

A 57-year-old man fell from a height of 6 m and injured his right foot. Imaging studies showed an uncommon injury; naviculocuneiform and calcaneocuboid joint fracture dislocations. He underwent a temporary fixation with Kirschner wires (K-wires), and the injured foot was immobilized with a below-knee splint. Weight-bearing was started gradually. The K-wires were removed at 8 weeks. Full weight-bearing was achieved 14 weeks after the operation. At 19 weeks, he returned to his carpentry job. At 1 year, he had no marked limitation of daily activities. Early recognition of these injuries is required to prevent persistent foot pain and long-term dysfunction.

Pathogenesis and surgical correction of dynamic lower scleral show as a sign of disinsertion of the levator aponeurosis from the tarsus.

The purpose of this study was to confirm whether lower scleral show is caused by the disinsertion of the levator aponeurosis from the tarsus. Aponeurotic advancement by vascular clips or by surgery involving the orbital septum significantly lowered the global position in the orbit and significantly diminished the degree of retraction of the lower eyelid, resulting in satisfactory improvement of lower scleral show in 100 patients with various aponeurotic blepharoptosis. Therefore, we propose the pathogenesis of lower scleral show as follows: additional contraction of the levator muscle to compensate for the disinsertion of the levator aponeurosis from the tarsus for maintenance of an adequate visual field is accompanied by additional contraction of the superior rectus muscle through the strong intermuscular fascia, resulting in upward rotation of the globe. To maintain the horizontal visual axis and foveation without inclination of the head in the primary gaze position, additional contraction of the inferior rectus muscle is induced, which pulls upon the inferior suspensory ligament of Lockwood and the capsulopalpebral fascia. The former displaces the globe upwards and the latter retracts the lower eyelid, resulting in dynamic lower scleral show as a sign of disinsertion of the levator aponeurosis from the tarsus, which can be surgically corrected.

Efferent and afferent innervations of Mueller's muscle related to involuntary contraction of the levator muscle: important for avoiding injury during eyelid surgery.

Because stretching of Mueller's muscle induces involuntary contraction of the levator muscle, we hypothesised that Mueller's muscle functions as a serial kind of muscle spindle of the levator muscle. To confirm the presence and location of efferent and afferent innervations of Mueller's muscle, cadavers' eyelids were microscopically and macroscopically examined, and the resultant findings were physiologically confirmed in patients' eyelids during surgery. Fine neural myelinated structures acting as a mechanoreceptor were found in the proximal Mueller's muscle. Mueller's muscle is doubly innervated by the unmyelinated sympathetic efferent nerve and the myelinated trigeminal proprioceptive afferent nerve, both of which run transversely on the proximal Mueller's muscle to join the lacrimal nerve. Electrical stimulation of the transverse nerve fibres induced involuntary contraction of both the levator muscle as the Hoffmann reflex and Mueller's muscle. Surgical injury to these nerve fibres should be avoided to preserve involuntary contraction of the levator muscle.