Osteosarcoma: A rare cause of painful enlargement of the hallux.

Malignant osseous and soft-tissue tumors of the foot are rare. We report a case of osteosarcoma in the proximal phalanx of the hallux in a 45-year-old man. In patients with foot-related symptoms, a high index of suspicion for pedal osteosarcoma is required. Delayed or inappropriate diagnosis may compromise limb-sparing surgery and survivorship.

Surgical and immediate post-release mortality of harlequin ducks (Histrionicus histrionicus) implanted with abdominal radio transmitters with percutaneous antennae.

Radiotelemetry is an essential tool in the study of free-ranging bird populations, and a variety of transmitter-attachment methods have been developed. A promising new method is abdominal implantation of a transmitter with a percutaneous antenna. Researchers using this technique should be concerned about and aware of mortality during surgery and during the immediate post-release period (the 14-day period following surgery). Of 307 radio-implant surgeries performed between 1995 and 1997 in harlequin ducks (Histrionicus histrionicus), 7 (2.3%) deaths were documented during surgery or anesthetic recovery. Of 295 birds released with implanted radios, 10 (3.4%) died during the immediate post-release period. Modifications to anesthetic procedures used in the 204 surgeries performed in 1996 and 1997 reduced mortality to 1.5% during surgery and 1.5% during the immediate post-release period. Anesthetic modifications included intubation of all birds, placement of birds on an elevated platform that allowed the head to rest at a level lower than the body during surgery, placement of a heated water blanket under the birds during surgery, monitoring of body temperature, and use of electrocardiogram and Doppler ultrasound to monitor heart rates and arrhythmias. Low levels of mortality associated with abdominal implantation of radio transmitters may be unavoidable, but mortality can be minimized with adjustments to anesthetic technique.

Subcutaneous implantation of satellite transmitters with percutaneous antennae into male polar bears (Ursus maritimus).

Male polar bears (Ursus maritimus) have not been successfully instrumented with satellite transmitters because they readily shed collar-mounted transmitters. Seven male polar bears were captured on the pack ice off the northern coast of Alaska and surgically implanted with satellite transmitters with percutaneous antennae into the subcutaneous space of the dorsal cervical region. Transmitters failed prematurely with lifetimes of 30-161 days (mean = 97 days). Efforts to relocate implanted bears after transmitters failed were not successful. The mean number of location solutions per transmitter was 204 (range 118-369). An average of 10% and 19% of the locations were accurate to <150 m and to 150-350 m, respectively. Our successful tracking of male polar bears, the high quality of locations obtained from transmitters with percutaneous antennae implanted in the subcutaneous space, and the low visibility of such units make further technical development worthwhile if the reason for premature failure of the transmitters can be determined.

Intra-articular calcaneal fractures: effect of open reduction and internal fixation on the contact characteristics of the subtalar joint.

Intra-articular calcaneal fractures are associated with significant long-term morbidity, and considerable controversy exists regarding the optimum method of treating them. The contact characteristics in the intact subtalar joint were determined at known loads and for different positions of the ankle and subtalar joint, using pressure-sensitive film (Super Low; Fuji, Itochu Canada Ltd, Montreal, Quebec). We measured the contact area to joint area ratio (pressure > 5 kg force/cm2 [kgf/cm2]) which normalizes for differences in joint size and the ratio of high pressure zone (>20 kgf/cm2) as a reflection of overall increase in joint pressure. Three simulated fracture patterns were then created and stabilized with either 1 or 2 mm of articular incongruity. Eight specimens were prepared with a primary fracture line through the posterior facet, eight with a joint depression-type fracture, and six with a central joint depression fracture. A measure of 1 to 2 mm of incongruity in the posterior facet for all three fracture patterns produced significant unloading of the depressed fragment, with a redistribution of the overall pattern of pressure distribution to parts of the facet that were previously unloaded.

Osteochondritis dissecans of the head of the talus.

We present a case of osteochondritis dissecans of the head of the talus, without a history of trauma. The clinical and radiological features and a 2-year and 3-month follow-up are discussed.

Aspiration arthrography of the hip joint. Its uses and limitations in revision hip surgery.

Seventy-one patients undergoing revision hip surgery over a 5-year period from 1988 to 1993 had aspiration arthrography of the hip as a preoperative investigation. Sixteen hips were found to be infected at operation. Preoperative aspiration yielded positive cultures in 11 of these 16 hips. There was identical correlation between the organisms isolated on aspiration and during surgery. There were 5 false positive cultures from the aspirates of the remaining 55 noninfected hips. All of the hips from which a true positive culture was obtained had either clinical or radiologic evidence suggestive of infection. Aspiration arthrography does not have a major role to play as a routine investigation prior to all revision hip surgery. It is recommended that its use be reserved for those hips in which there is either clinical, hematologic, or radiologic evidence of infection.

One stage surgical management of deep infection of total hip arthroplasty.

Nineteen patients underwent one stage surgical management of infected hip prostheses over a five year period. Thirteen were male and six were female. The mean age was 64 years (Range 49-82). The mean time interval between primary and revision surgery was 26 months (Range 6 months-16 years). One stage re-implantation was performed in 15 patients and excision arthroplasty in 4 patients. The mean duration of follow up was 4 years, 5 months (Range 2-7 years). Patients were assessed, radiologically and clinically using the Harris hip score. Staph. aureus(7) and Slaph. epidermidis(10) were the most frequent organisms isolated. Patients who underwent excision arthroplasty had discharging sinuses, extensive soft tissue and bone involvement or were poor anaesthetic candidates. Three of these patients had a poor outcome in terms of pain function and deformity. Five of the patients who underwent one stage re-implantation had an excellent clinical result, seven had a good result, one had a fair result and one a poor result. There was no recurrence of infection in either group of patients. One stage re-implantation can result in a good clinical outcome and eradication of infection. Resection arthroplasty is a necessary option in a minority of patients, however, while successful in eradicating infection may result in a poor functional outcome.

Intraoperative suction catheter tip contamination.

Suction catheter tip contamination is a potential source of intraoperative inoculation of wounds with bacteria. The continuous passage of large quantities of air through a blood-soaked catheter tip during the course of surgical procedures can lead to significant contamination. This in turn may contribute to late wound infection due to inoculation of the deeper recesses of the wound via the contaminated suction catheter tip. We have conducted a prospective clinical study to confirm the incidence of suction catheter tip contamination during orthopaedic trauma surgery and propose changes to current practice to reduce the incidence.