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 pioneering local orthopaedic surgeons--Mr W G S Fung, Mr K H Yeoh, and Mr V K Pillay--joined the orthopaedic service in 1961. In 1967, Prof Pillay and Mr Fung took the leadership role at the University Orthopaedic Department and Government Orthopaedic Department, General Hospital, Singapore, respectively. Subspecialty services in orthopaedic surgery began in the late 1970s, and currently, at least 7 subspecialties have developed to divisional status at one or more hospitals. In 2001, there were 92 registered Orthopaedic specialists and just over a third were in private practice.

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. It was possible to raise a corticocancellous bone graft from the anterior surface of the radial styloid on a pedicle of the lower fibres of the pronator quadratus muscle. This muscle pedicle had a constant branch of the anterior interosseous artery which vascularized the bone graft. Such a vascularized pedicled bone graft may be useful in the treatment of non-union of the scaphoid and Kienböck's disease.

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. The treatment principles are continuous tube drainage, nutritional support and reduction of chyle production. In 50% of cases a surgical procedure will be required. There are a variety of techniques available. We describe a technique that uses a pedicled intercostal muscle flap, which to our knowledge, has not been described previously. Among the other techniques, video-assisted thoracoscopic surgery is the most promising because of its low morbidity.

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. Of 5167 patients who attended the Mount Elizabeth Hospital in Singapore for cervical spine complaints, 43 patients were found to have ossification of the posterior longitudinal ligament, forming the largest non-Japanese series. All but one patient were of Mongolian origin, and males were affected four times more commonly than females. Diabetes mellitus was present in 16%. There was a significant association between ossification of the posterior longitudinal ligament and calcification of other cervical paraspinal ligaments. It is suggested that a generalized tendency to calcification may be an important etiological factor in ossification of the posterior longitudinal ligament. Four of the patients required surgery, and in our experience, anterior spinal fusion with removal of the ossified ligament or multilevel laminoplasty gives satisfactory results.

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. A careful clinical assessment that includes new radiographs and, if necessary, bone scans is essential for early diagnosis in patients who have acute, incapacitating pain in the knee.

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. A vascularised bone graft can be raised on a pedicle of muscle attachment or a main axial vessel, but the mobility of the vascularised pediculated graft is limited by the length of its pedicle. The vascularised muscle-pedicle graft of the ipsilateral fibular shaft described by Chacha et al has been proved viable both in monkeys and in humans. The shaft is raised on a pedicle of the peroneal vessels and the peroneal and the anterior tibial muscles, and provides an excellent viable bone strut to bridge a large defect in the tibial shaft. Judet's quadratus femoris muscle-pedicle graft from the greater trochanter has proved superior to Phemister's tibial cortical or fibular strut graft for the treatment of non-union of the femoral neck and the silent-phase of avascular necrosis of the femoral head. The tensor fascia lata muscle-pedicle graft of the anterior iliac crest, described by Davies and Taylor, provides a good viable bone strut for anterior hip fusion and for filling defects in the acetabulum and the upper femur. The whole of the greater trochanter attached to a thick pedicle of the gluteal muscles can be used as a live extra-articular graft for hip fusion. A pedicular rib graft raised on its intercostal vessels, as described by Rose et al. and Bradford, is a very useful live bone strut for correction of kyphosis and grafting of infective lesions of the vertebral bodies. The cortical graft of the radius within the radial forearm skin flap for reconstruction of the thumb, the pronator quadratus muscle-pedicle graft of the lower radius for non-union of the scaphoid and avascular necrosis of the lunate, and the erector spinae muscle-pedicle graft of the posterior ilium for intertransverse fusion are new concepts which need to be evaluated for wider clinical application.

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. Transfer of part of the shaft of the ipsilateral fibula on a vascular and muscle pedicle was carried out in 11 patients with large tibial defects and sepsis. There was one failure because of severe infection, but the other 10 patients gained sound union in about four months. The tibia was then protected by a caliper for the 18 months of full reconstitution. The bone infection healed and there was no evidence of avascular necrosis. Although the salvaged limbs were scarred, stiff and ugly, none of the patients suffered from pain, recurrent oedema or persistent infection.

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. The use of an adequate incision for good exposure of the carpal tunnel and all its contents is recommended.

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. A beam splitter and camera equipment are essential accessories. Microsurgical instruments are delicate and expensive and must be bought with discretion and carefully protected. Fine dissecting forceps, needle holder, microscissors, microvascular clamps and clips and fine haemostats are the only essential instruments. Others are optional. Microsutures form the most expensive part of the microsurgical setup. 10-0polyamide suture mounted on a curved round bodied needle of 4 or 5 mm length is adequate for virtually all clinical and experimental microsurgical work.

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.

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. Group I patients presented with a sudden onset without any previous symptoms related to the back. Group II patients had a history of recurrent episodes of backache and sciatica, the latest episode resulting in involvement of the cauda equina. The group III patient was indistinguishable from one with a tumour as he presented with backache and sciatica slowly progressing to paralysis of the cauda equina. The prolapse was at the disc between L5 and S1 vertebrae in 50 per cent of the patients, most of whom did not have any limitation of straight leg raising. Urgent myelography and equally urgent removal of the disc within two weeks of the onset of the symptoms resulted in almost complete motor and bladder recovery within five months after the operation in most cases. However, recovery of sensation and sexual function was incomplete even four years after the operation.

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. The demonstration of nerve fiber and the presence of normal specific and non-specific cholinesterase reactions exhibited by the Meissner's corpuscles in the cholinesterase preparations were considered the histological criteria for successful reinnervation. These histological and histochemical observations may explain the reported functional sensory recovery in clinical cases when similar nerve transfers were done.

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. Displaced fractures, however, always required internal fixation with thin pins after accurate correction of displacement. The various complications of this fracture in children are discussed. Acute necrosis of articular cartilage following this fracture in children is recorded for the first time in 2 cases.