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Since the beginning of time, our ancestors have been plagued by illnesses and injuries that are not too different from today's diseases. Evidence from prehistoric times and ancient civilisations have shown man's attempts at trying to understand the nature and treatment of these conditions. It was not till the early 19th century that the scientific basis of modern medicine was firmly established when microorganisms were discovered and found to be the cause of many of these illnesses. The 20th century saw quantum leaps made in the understanding of the function of the human body and the therapeutic measures aimed at restoration of any such malfunction. The end of the last millennium was marked by historic achievements made in the Life Sciences, in particular the completion of the sequencing of the Human Genome--the code of life. The beginning of the 21st century has already seen many breakthroughs in medical sciences, especially in the fields of stem cell technology and gene therapy. The number of known illnesses directly related to genetic defects or abnormalities have increased exponentially. Many of today's scourges can be prevented or more effectively treated. Our ability to utilise this new knowledge to combat the ravages of the ageing process and its associated illnesses--degenerative diseases and cancers offer much hope for the future.

Introduction: The prevalence of deep vein thrombosis after total knee replacement has been quoted to be between 46% and 84% in the Western literature. The aims of this study were to determine its prevalence in the Singapore population and to assess the need for prophylaxis against deep vein thrombosis., Materials and Methods: We examined data on 100 consecutive patients undergoing total knee replacement at the Adult Reconstructive Service, Department of Orthopaedic Surgery, Singapore General Hospital and assessed the possible risk factors: age, sex, weight, previous surgery, unilateral or bilateral surgery, postoperative rehabilitation, tourniquet and operating time. Functional and knee scores based on the Knee Society Clinical Rating System were also assessed. No prophylaxis was given to these patients. These patients underwent a duplex scan of both lower limbs on the seventh postoperative day. Treatment was instituted only if proximal deep vein thrombosis was detected., Results: The overall incidence of deep vein thrombosis was 14% with 64.3% of it occurring distally. Deep vein thrombosis was more common in bilateral total knee replacement (22.2%) compared to unilateral total knee replacement (13.2%). Partial thrombosis was present in 71.4% and occurred predominantly in the ipsilateral leg. There was no evidence of propagation. Only 1 patient developed pulmonary embolism and was treated successfully but there was no evidence of deep vein thrombosis on duplex scan in this patient., Conclusion: There was no significant difference in the risk factors between patients who did and those who did not develop deep vein thrombosis.

Resection of a vertebral body for spine tumour or fracture results in a vertebral gap which has to be bridged by autogenous graft, allograft, bone cement or metal spacer. Recently, there have been several metal spacers in the market. We have designed a titanium vertebral spacer which is extensible by way of a threaded mechanism. Coating with hydroxyapatite enables bone ingrowth onto the surface of the titanium spacer. Biomechanical analysis, using the Instron biaxial electro-servohydraulic testing machine, showed that the segment bridging the spacer was rigid and stiffer than the adjacent vertebral body motion segment. Histological study showed that there was bone growth across the vertebral gap indicating fusion had taken place.

A retrospective study was made between July 1988 and March 1992, of 171 patients (223 knees) who had high tibial osteotomy at the Singapore General Hospital. Seventy-four cases (97 knees) had buttress plate fixation and 97 cases (126 knees) had staple fixation. The mean postoperative Hospital for Special Surgery Knee Score was 87.0 for the buttress plate group and 87.4 for the staple group. The difference was statistically not significant (P > 0.05). The hospitalisation stay was shorter in the staple fixation group as compared to the buttress plate group (P < 0.05). However, the mean rehabilitation time was shorter in the buttress plate group as compared to the staple fixation group (P < 0.05). The incidence of wound infection was higher among those fixed with buttress plate (9 cases) as compared to those fixed with staple (1 case). The difference was statistically significant (P < 0.05). Buttress plate fixation did not seem to eliminate the risk of non-union of the osteotomy (4 out of 126 osteotomies compared to 3 out of 97 in the staple group), neither did it prevent recurrence of varus deformity (2 out of 126 osteotomies). Overall it would appear that buttress plating did not have any significant advantage over staple fixation for high tibial osteotomy.

A retrospective study of the arthroscopic treatment of osteochondral lesions of the talus in 25 patients was conducted. The follow-up period ranged from 1 to 4 years with an average of 2 years. Of the 25 patients, 20 could recall a history of injury. The diagnosis could be made by standard anteroposterior and lateral X-rays in 22 out of 25 patients. The standard anteromedial and anterolateral portals were usually sufficient. Patients with stage I and II lesions did well uniformly. In the 16 patients with stage III and IV lesions, good results were obtained in 12 and fair in 4. Morbidity was minimal.

Injuries of the tarsometatarsal (Lisfranc's) joint are uncommon and are potentially associated with chronic disability. The aim of our study was to review retrospectively the results of open reduction with Kirschner wire internal fixation of tarsometatarsal injuries. In this study, 12 patients with Lisfranc's injuries treated between January 1986 and March 1993 were reviewed at an average of 36 months after the injuries. Majority of the patients suffered from type B injuries (Hardcastle's classification, 1982). There were 9 closed and 3 open injuries. All were high energy injuries sustained in motor vehicle accidents, fall from a height or crush force. All were treated with open reduction and internal fixation with Kirschner wires. Anatomical reduction was achieved and maintained. There was no postoperative redisplacement. During follow-up, most patients developed radiological evidence of post-traumatic osteoarthritic changes. However, majority of the patients were pain-free or had very little foot pain, and were able to return to their previous occupation. Our study showed that open reduction with Kirschner wire internal fixation offered satisfactory anatomical and functional results.

The accessory navicular is a known cause of foot pain. When symptomatic and conservative measures have failed, surgical intervention may be required. Simple excision of the ossicle or the Kidner procedure with transplantation of tibialis posterior tendon to the undersurface of the navicular bone may be done. Eighteen patients with symptomatic accessory navicular were reviewed at the Singapore General Hospital, Department of Orthopaedic Surgery 'O' Unit. All 18 patients had foot pain and restriction of activities. Thirteen noticed a prominence on the medial side of the affected foot and 7 had difficulty with shoe fitting. Nine underwent simple excision of the ossicle while the other 9 had the Kidner procedure done. The average follow-up period was 3.1 years. Both the simple excision and the Kidner procedure were equally successful in relieving symptoms in 15 out of the 18 cases. The Kidner procedure did not confer any particular advantage over simple excision.

The lack of effectiveness of growth hormone in stimulating the healing of fresh fractures has been attributed to the presence of insufficient precursor osteogenic cells at the fracture site for the growth hormone to exert its influence. We tested the effect of growth hormone on healing in a rabbit non-union model after injection of autogenous marrow cells into the fracture gap. Two millilitres of bone marrow were injected percutaneously into 1 cm diaphyseal defects of rabbit radii. The test group was given subcutaneous human recombinant growth hormone at 0.3 IU/kg/day in divided doses for 2 weeks, while the control group received subcutaneous saline injections. Biomechanical, radiological and callus calcium content assessments were carried out at 4 and 7 weeks. There was significantly increased tensile strength and callus calcium concentration in the group given growth hormone both at 4 and 7 weeks but there was no significant difference in stiffness or in callus volume in the 2 groups. These data suggest that growth hormone can enhance the osteogenic potential of bone marrow as a graft in the treatment of fracture non-union.

Between January 1992 to June 1993, 93 ankle fractures underwent surgical treatment, of which, 10 patients were diabetic and 83 were non-diabetic. Infection occurred in 5 patients and all belonged to the diabetic group. The average follow-up period of the infected cases was 16.2 months. Wound infection occurred in 4 patients treated with open reduction and internal fixation. An infected pressure sore developed in the other patient treated initially in a below-knee cast for which arthrodesis of the ankle was performed. Infection was resistant to treatment in 2 patients and they ended up with below-knee amputation. Infection resolved in 3 patients with treatment. Of these, 1 developed neuropathic ankle joint and the other 2 achieved fracture union.

Between 1988 to 1991, 80 cases of de Quervain's disease were managed at the Department of Orthopaedic Surgery, Singapore General Hospital. Six of them had an associated ganglion over the first dorsal retinacular compartment. Five out of 6 cases had intracompartment injections of hydrocortisone and lignocaine but the treatment was not effective in relieving the pain of de Quervain's tenosynovitis. All 6 cases had excision of the ganglion and decompression of the first extensor compartment. All the lumps were found arising from the dorsal aspect of the retinaculum and no intracompartment extension of the ganglion was found.

Between January 1989 and December 1990, a study was conducted on the social aspects of 123 patients admitted to the Singapore General Hospital, Department of Orthopaedic O, with proximal femoral fractures. Twenty-three patients passed away, leaving 100 patients for review at 2 years post-fracture. Of the 20 social functions evaluated, less than 60% improvement was observed in 6 lower limb dependent activities. Before fracture, 82 patients were independent and 83 were ambulating without aids. After fracture, improvement occurred progressively and reached a plateau at 1 year with 62 (75.6%) patients independent and 41 (49.4%) patients ambulating normally. All the patients stayed in their own home before fracture and 90 (90%) patients returned to their home after their discharge. Of the 59 patients who were unable to ambulate without aids, 21 had visual problems, 9 had cerebrovascular accident and 8 had both problems.

This study allows the establishment of a protocol for standardizing the technical methodology of canine surgery for mechanical testing. Twenty mongrels were divided into 4 groups of 5 dogs each. All dogs had one femur selected as the test bone and the contralateral as paired control. The test femur was osteotomized and plated. The dogs were sacrificed at 7, 10, 13 and 16 weeks according to their group designation to determine healing of the osteotomy. Both test and control femora were tested to fracture in torsion using a computerized torsion machine. Various mechanical parameters were studied with the age of osteotomy union. The study found that all bones sustained spiral fractures through the osteotomy site. The maximum torque capacity and stiffness increased with age of union. There is an apparent biphasic pattern in the remodelling process. Up till the 13th week there was a decline in the polar moment of inertia and a rise in the torsional stress with an increase in strength. We postulate that this was due to a reduction of the outer diameter of the external bridging callus. After the 13th week, there was a reversal in the process and the outer diameter of the callus increased. The findings provide a baseline reference for future studies involving osteotomy healing as is necessary in bone allograft reconstruction and bone transport.

Between May 1985 and December 1990, 20 patients with rheumatoid arthritis had 34 total knee replacements performed. The mean follow-up period was 4.1 years and the range was 2.3 to 7.8 years. Five knees with total knee replacements (74.7%) in 4 patients were affected by activation of the rheumatoid process at an average postoperative interval of 28.6 months while the other 29 knees with total knee replacements (85.3%) remained in remission. Factors that appeared to have an influence on post total knee replacement rheumatoid activation included the activity of the disease preoperatively, and whether synovectomy was undertaken at surgery. Whether patella replacement was undertaken appeared not to have influenced postoperative reactivation of the disease. Using the Hospital for Special Surgery Knee score, total knee replacement in our cases gave excellent results. The complications included one knee with dislocation of the patella and another with infection.

A total of 109 consecutive total condylar knee replacements in 73 patients were assessed at one to eight years postoperatively. The average age at surgery was 66.9 years and the range was from 52 to 84 years. The primary disease was rheumatoid arthritis in 12 and degenerative osteoarthritis in 97 knees. Out of the 109 prostheses; 101 were Miller-Galante kinematic condylar type I or II prostheses, seven were Insall-Burstern type I or II and one was a Whiteside prosthesis. The fixation technique was hybrid (only the tibial prosthesis cemented) in 63, both components uncemented in two and both components cemented in 44 knees. One hundred and five (96.3%) knees showed significant improvement in the Hospital for Special Surgery score postoperatively. The average preoperative score was 48.1 and the postoperative score was 85.4. Sixty-four patients (100 knees) were satisfied or very satisfied with the result of surgery. One hundred and four (95.4%) knees had achieved either an improvement in the range of motion and/or deformity. Complications included loosening in four (3.7%) knees, infection in three (2.8%), dislocation of the patella in four (3.7%), periprosthetic fracture in one (0.9%) and severe lateral collateral ligamentous laxity in one (0.9%).

Eighty-four consecutive cases of ankle arthroscopy performed between 1985 and 1990 were reviewed. These patients had all undergone conservative treatment for at least six months for chronic ankle pain. This consisted of non-steroidal anti-inflammatory agents, physiotherapy and/or immobilisation. Arthroscopy was performed when there was no response to conservative treatment. Eighty-one percent (68) of the patients were between the ages 20 and 29 years. Eighty-nine percent (75) were male. The most common lesions identified were transchondral fractures, localised synovitis, osteoarthritis and loose bodies. These were treated by arthroscopic surgery which included debridement, removal of loose bodies and abrasive chondroplasty. All the patients were followed up for at least one year or until they were asymptomatic. Excellent results were observed in transchondral fracture, localised synovitis associated with chronic lateral ligament instability, loose bodies, anterior impingement syndrome, osteochondritis dissecans and meniscoid syndrome. Good to fair results were obtained in osteoarthritis and fibroarthrosis. There were no intra-operative or postoperative complications.

We describe a case of localised amyloidosis of the distal ureter in a 66-year-old lady who presented with intermittent haematuria. Ureteric transitional cell carcinoma was strongly suspected from the clinical and radiological features, and subsequent nephroureterectomy was performed. Histology revealed nodular eosinophilic deposits in the ureteric wall, with the staining characteristics of amyloid. The literature is reviewed, and conservative surgery is advocated, based on a greater awareness together with improved intraoperative diagnosis of this rare lesion.

A rare case of an unruptured ovarian ectopic pregnancy is reported. This patient had a dilatation and curettage for an incomplete abortion and no products of conception were revealed in the histology specimen. A repeat ultrasound scan detected an ectopic pregnancy. Laparotomy confirmed the diagnosis of an unruptured ovarian pregnancy. The problems with the diagnosis and the management of this case are discussed.

Immunoprecipitation assays for antibodies to the nicotinic acetylcholine receptor are a specific test for the diagnosis of myasthenia gravis. However, testing has largely been confined to reference laboratories because the preparation of the reagents is laborious, making it less accessible to practising clinicians locally. We recently acquired a test kit produced by RSR Ltd (Avenue Park, Pentwyn, Cardiff) which makes testing of serum samples practicable in smaller centres. We describe our experience in establishing normal and control values in 30 separate samples. We also assayed the sera of ten patients with thyroid disease, some of whom had ophthalmopathy and/or weakness due to periodic paralysis, and none of these tested positive. Three additional patients with thyroid disease and concurrent myasthenia gravis were also inadvertently included in the latter assay and two had high titres and one had equivocal titres. The assay is now run regularly every quarter of the year.

Granular cell tumour is a rare tumour of undetermined origin. Fewer than 1000 cases have been reported and less than 40 cases of malignant forms of this tumour have been described in the literature. We report a single case of the malignant form of granular cell tumour in the lower limb and review the literature regarding the possible origin of this tumour. Presently, wide surgical excision is the only modality of treatment for this lesion.

Fine needle aspiration (FNA) is a relatively new technique in the investigation of head and neck masses in Singapore. We present our initial experience with 123 neck masses; 82 were lymph nodes, 33 were salivary gland masses and eight were others. The inadequacy rate (percentage of hypocellular yields) was 12.2% with a cytology: histology accuracy rate of 82.6%. The aspiration trolley set-up and improvements in tissue handling reduced the number of inadequate smears. A study of nasopharyngeal carcinoma (NPC) with neck recurrence showed the difficulty encountered with FNA in irradiated necks. In "occult" (clinically normal nasopharynx) NPC with a neck mass as the first presentation, FNA guided us to re-search the nasopharynx.

A vascular necrosis of the femoral head associated with steroid immunosuppression is a cause of significant morbidity in renal transplant recipients. We review the results of 30 total hip replacements in 20 renal transplant recipients with a mean follow-up of 6.3 years. The mean age at the time of surgery was 35 years. The average Hospital for Special Surgery Hip Score was 17 points before operation and 32 points after operation. Fourteen hips were rated excellent and 12 hips rated good. There were four failures--one hip was revised for symptomatic loosening and three prosthesis were removed for infection. Twenty-seven of the hip replacements were subjectively rated as satisfactory by the patient. There was no significant difference in post-operative hip scores between cemented and uncemented prostheses. Total hip replacement in renal transplant recipients in this study has shown good long term result with a revision rate of about 3%. Late infection was a major problem with an incidence of 13%. Prophylactic antibiotics must be used whenever there is a risk of haematogenous seeding from transient bacteremia in these immunosuppressed patients. Use of uncemented prosthesis may make future revision arthroplasty easier.

Risk of malignant transformation in a dysgenetic gonad is high. This is a report of a 23 year-old female who presented with symptoms and signs of ovarian neoplasm which was histologically confirmed as embryonal carcinoma. She had features of Turner's syndrome and was found to have XO chromosomal constitution. Embryonal carcinoma arising in a dysgenetic gonad is uncommon. It is even rarer when it arises in a patient with pure 45 XO. The following is a case report which highlights the role of chemotherapy and surgery in the management. It includes a literature review on the clinical features, genetic variants and malignant transformation in dysgenetic gonad. The role of prophylactic removal of dysgenetic gonad is discussed.

A rare case of extraskeletal osteogenic sarcoma of the right groin in a 50 year old Chinese lady is being presented. A wide excision of the tumour was done. The differential diagnosis are discussed. This is an extremely rare tumour and is just as malignant and aggressive, if not more so than its counterpart in the bone.

Chondrosarcoma arising from the spine is a rare malignant tumour, associated with a poor outlook due to inadequate excision in the majority of the cases. We report two cases arising from the cervical and the thoracic spine. Both survived 15 and eight years respectively. This condition carries with it a grave prognosis because of its proximity to the vital structures, making complete extirpation of the tumour frequently difficult if not impossible. Recent developments and progress in adjuvant radiation therapy has improved the prognosis significantly.

A case of osteosarcoma in a 14 month old girl is reported. The child presented with a history of difficulty in standing for 2 months and x-rays revealed an osteolytic lesion in the upper third of the femur associated with widening of bone and periosteal reaction. Osteosarcoma was diagnosed by biopsy. Treatment was refused and the child died 13 weeks later. Only one other case of osteosarcoma in a child as young as 14 months has been reported. A review of literature showed 22 cases of osteosarcoma in children aged 5 years or younger.

Cancers of the scalp are uncommon. Owing to their unique site they pose problems in surgical treatment. A retrospective study of all scalp cancers notified to the Singapore Cancer Registry over 17 years has shown that squamous cell carcinoma is the most common cancer followed by basal cell carcinoma. Other cancers are sweat gland carcinoma, angiosarcoma, dermatofibrosarcoma protruberans, liposarcoma, fibrosarcoma and malignant lymphoma. Scalp cancers are more common in Chinese and very rare in Indians. There is no difference in the incidence between the sexes. The surgical treatment and reconstructive techniques employed in 52 patients are described. When localised, scalp cancers are managed like other skin cancers but once they invade bone, they become aggressive and are difficult to eradicate. Wide radical excision provides cure and the skull bone if involved should be removed.

A patient, with two previous term deliveries, presented with post-partum haemorrhage and spontaneous uterine perforation due to choriocarcinoma, requiring emergency laparotomy. Choriocarcinoma following term pregnancy is a rare form of gestational trophoblastic disease. Such tumour appears to follow a more aggressive course with a more extensive metastatic spread and is less responsive to chemotherapy resulting in a poorer prognosis. Choriocarcinoma presenting as postpartum haemorrhage, and spontaneous tumour perforation with intra-abdominal haemorrhage is even rarer. Early diagnosis is an important factor for the patient's survival. A high index of suspicion is required as the tumour may be overlooked. An aggressive chemotherapeutic regime has improved the overall survival.