Neuronal identities derived by misexpression of the POU IV sensory determinant in a protovertebrate.

The protovertebrate type A (sometimes called ) contains a series of sensory cell types distributed across the head-tail axis of swimming tadpoles. They arise from lateral regions of the neural plate that exhibit properties of vertebrate placodes and neural crest. The sensory determinant is known to work in concert with regional determinants, such as and , to produce palp sensory cells (PSCs) and bipolar tail neurons (BTNs), in head and tail regions, respectively.

History of the orthopaedic specialty in Singapore.

The Orthopaedic specialty service in Singapore began in 1952 with the appointment of J A P Cameron to the chair of Orthopaedics at the University of Malaya and the simultaneous establishment of the Department of Orthopaedic Surgery at the General Hospital, Singapore. A second department--a government department of orthopaedic surgery was established in 1959, under the headship of Mr D W C Gawne also at the General Hospital, Singapore to cater to the increasing workload. Although orthopaedic services were already available at Alexandra Hospital, Tan Tock Seng Hospital and Toa Payoh Hospital from as early as 1974, the formal establishment of a Department of Orthopaedic Surgery in these hospitals took place only in 1977.

The anatomical basis of the vascularized pronator quadratus pedicled bone graft.

The vascular supply of the pronator quadratus was studied in 25 cadaveric dissections following coloured latex injections. This showed that the main blood supply of the pronator quadratus came from the anterior interosseous artery. There was, however, a rich anastomosis between the branches of the anterior interosseous artery and those of the radial and ulnar arteries.

Massive chylothorax after anterior fusion of the thoracic spine.

We report a case of massive chylothorax occurring postoperatively in a patient with Potts paraplegia who underwent transthoracic anterior debridement and fusion of the T7 and T8 vertebrae. This is an uncommon complication of anterior spinal surgery but has a significant morbidity and mortality. Diagnosis of the condition and the institution of the appropriate therapy will reduce this significantly.

Ossification of posterior longitudinal ligament of the cervical spine in non-Japanese Asians.

"The Japanese disease," ossification of the posterior longitudinal ligament, is not confined to the Japanese only. A similar incidence of 0.8% was found in this study among non-Japanese Asians.

Stress fractures around the knee in elderly patients. A cause of acute pain in the knee.

A review of the cases of sixteen elderly patients who had eighteen stress fractures around the knee revealed that thirteen fractures had been misdiagnosed, which led to inappropriate management of six. The most frequent factor contributing to misdiagnosis was the presence of other abnormalities of the knee for which the patient had previously consulted the physician. Conservative treatment with rest, walking aids, and, for some patients, splinting of the extremity resulted in relief of pain and healing of the fracture.

Vascularised pedicular bone grafts.

When a massive free bone graft has to be incorporated into a large bone defect in the presence of a poor vascular recipient bed, the risks of absorption and failure of the graft to revascularise are high. Experimental studies have confirmed that a bone graft transferred to its recipient site with an intact pedicle of blood supply remains viable, and unites directly with the recipient bone without having to be revascularised and replaced by creeping substitution. It also provides a live bone bridge for reconstruction of a massive bone defect, and is a ready source of vascular osteogenic tissue which sprouts new outgrowths to revascularise avascular recipient bone.

Vascular pedicle graft of the ipsilateral fibula for non-union of the tibia with a large defect. An experimental and clinical study.

Failure of union of the tibia with a large defect is difficult to treat, especially in the presence of sepsis and adherent scars. Conventional methods of fixation and bone grafting are not easily applicable. Experiments on Macaca monkeys showed that a vascularised pedicle graft of the shaft of the ipsilateral fibula could be fixed across a defect in the tibia and remain viable, even if it was isolated from surrounding soft tissues.

Acute carpal tunnel syndrome secondary to thrombosis of a persistent median artery (with high division of the median nerve). A case report.

An unusual case of median nerve compression due to thrombosis of a persistent median artery with a high division of the median nerve is described. The most probable case of the thrombosis is probably the repeated stretch and vibration that is associated with the use of a stiff clutch in a new motor cycle. This report serves to emphasise the need for early diagnosis and in immediate decompression in such cases.

Replantation of digits using microvascular technique.

This paper reports our experience of replantation of 31 digits. The operative technique and sequence of replantation is described. We have attempted to classify the functional results into three groups: near normal, useful and useless digits.

Operating microscope, microsurgical instruments and microsutures.

A comprehensive knowledge of operating microscope, microsurgical instruments and microsutures is most essential for any beginner in this field. Magnification provided by an operation microscope is higher and variable to suit microsurgical procedures. Although zoom magnification and focussing are preferable for convenience, microscopes with manual controls can be used for clinical and experimental work.

Rerouting vessels and nerves from other digits in replanting an avulsed and degloved thumb.

In avulsion and degloving injuries of amputated thumbs, we have rotated nearby neurovascular bundles and dorsal digital vessels to restore circulation and sensation. This has been done in 5 patients, and 3 thumbs survived with preservation of length and good function.

Midline prolapse of a lumbar intervertebral disc with compression of the cauda equina.

Midline prolapse of a disc causing compression of the cauda equina is rare but needs urgent diagnosis and surgical treatment. The onset of bladder and rectal paralysis with saddle anaesthesia should be viewed with a high index of suspicion in a patient with backache and sciatica. Eight cases were seen over a period of five years, and they fell into three clinical groups.

Primary repair of flexor tendons within the digital theca of the hand.

The results of primary repair of the flexor tendons within the digital theca of the hand in twenty-three fingers have been very encouraging. Eighty-seven percent of the fingers had excellent to good results. Primary tenorrhapy by the technique described in selected cases offers the patient a shorter period of disablement with functional results as good or even better than those after a free tendon graft.

Experimental sensory reinnervation of the median nerve by nerve transfer in monkeys.

Anastomosis of the superficial radial nerve, the dorsal cutaneous branch of the ulnar nerve, or both to the distal cut end of a widely resected median nerve in monkeys was followed by successful sensory reinnervation of the thumb, index finger, and long finger within thiry-five to forty weeks. Success was ascertained by the presence of an intact anastomosis as observed grossly without any evidence of spontaneous regeneration of the median nerve. Reinnervation was confirmed by histological and histochemical reactions observed in the Meissner's corpuscles in the skin innervated by the median nerve.

Fractures of the neck of the femur in childhood and adolescence.

Twenty cases of fracture of the neck of the femur in children and adolescents below the age of 20 were reviewed. The most important single prognostic factor was the degree of displacement of the fracture at the time of injury. Undisplaced fractures, whether treated conservatively or by internal fixation, did well.