Percutaneous fluoroscopic removal of a knotted Swan–Ganz catheter in a patient with a persistent left‐sided superior vena cava

Knotting of intravascular catheters is an uncommon but a well‐recognized occurrence. The Swan–Ganz catheter (SGC) is the one that knots most commonly. A case of a knotted SGC is described in a patient with a persistent left‐sided superior vena cava, and we propose that the presence of a left‐sided superior vena cava is a risk factor for knot formation not previously reported. We review the published work on the risk factors for knot formation and on the techniques used to remove knotted SGC. We describe a technique using a gooseneck snare and Omni Flush catheter (Angiodynamics, Queensbury, NY, USA) to loosen and untie a knotted SGC.     

Outcome of uncemented hip arthroplasty components in patients with Paget's disease

The outcome of uncemented hip arthroplasty in patients with Paget's disease is unknown. The clinical and radiographic records of patients with Paget's disease affecting the hip who had total hip arthroplasty using uncemented components against pagetic bone were reviewed. There were 18 patients (19 hips) with an average age of 71.3 years (range, 54-85 years). Followup averaged 7 years (range, 2-15 years). Surgery often was reported to be demanding technically because of hard sclerotic bone and excessive bleeding in some patients. Estimated blood loss averaged 996 mL (range, 200-2500 mL). Harris hip scores improved significantly. There was clinical and radiographic evidence of bone ingrowth in all patients. Six of 19 hips had heterotopic bone. One hip had severe Brooker Grade IV heterotopic ossification and the patient required excision of the ossification at 5 years. One hip was unstable (subluxating) at the latest followup. There was no revision for component loosening and no recognized cases of clinical or radiographic loosening of any uncemented implants. Results of total hip arthroplasty using uncemented components in patients with Paget's disease are excellent overall, with an extremely low risk of component loosening during the first decade after implantation. These patients may be at higher risk for heterotopic bone formation and increased perioperative blood loss because of hypervascularity of the bone.     

Thirty-day mortality after total knee arthroplasty

BACKGROUND: There have been sporadic reports on perioperative mortality associated with total knee arthroplasty. The purpose of this study was to determine risk factors for such mortality. METHODS: A computer-assisted review of the records of 22,540 consecutive patients who had undergone total knee arthroplasty between 1969 and 1997 was performed to identify all patients who had died within thirty days after the procedure. A detailed analysis of the medical, surgical, anesthetic, and pathological records of the patients was performed, and the mortality was determined according to age, gender, diagnosis, and fixation method. RESULTS: The rate of mortality within thirty days after the operation was 0.21% (forty-seven of 22,540). All deaths occurred in the group of 18,810 patients who had received a cemented implant, and no deaths occurred among the 3730 patients who had received an uncemented implant (p < 0.0001). The mortality rate was 0.24% (forty-three of 18,165) after primary arthroplasty and 0.09% (four of 4375) after revision arthroplasty (p < 0.0003). Three patients (0.01%) died during the operation. Forty-three of the forty-seven patients who died had a history of preexisting cardiovascular and/or pulmonary disease. Simultaneous bilateral total knee arthroplasty was associated with a significantly higher rate of perioperative mortality (p < 0.002). CONCLUSIONS: Factors that were associated with a significantly increased mortality after total knee arthroplasty included an age of more than seventy years, primary (as compared with revision) knee surgery, use of a cemented prosthesis, preexisting cardiopulmonary disease, and simultaneous bilateral arthroplasty.     

Thirty-day mortality after elective total hip arthroplasty

BACKGROUND: Previous reports on perioperative mortality associated with hip arthroplasty have not documented, to our knowledge, patient characteristics and surgical factors that increase the likelihood of death. The purpose of this study was to determine the prevalence of and associated risk factors for perioperative death after elective hip arthroplasty. METHODS: The records of 30,714 consecutive patients who had undergone elective hip arthroplasty at our institution from 1969 to 1997 were retrospectively reviewed to identify patients who had died within thirty days after the procedure. Mortality rates were determined according to age, gender, diagnosis, implant type, and fixation mode. RESULTS: Ninety deaths occurred within thirty days after elective total hip arthroplasty, for an overall mortality rate of 0.29% (ninety of 30,714). The thirty-day mortality rate was significantly higher for patients with preexisting cardiovascular disease (p < 0.0001), male patients (p < 0.0001), and patients who were seventy years of age or older (p < 0.0002). The mortality rate was slightly, but not significantly, higher for patients with an underlying diagnosis of rheumatoid arthritis (p < 0.36) and those receiving cemented implants (p < 0.57). There was no difference in the thirty-day mortality rate for revision as compared with primary hip arthroplasty (p < 0.92). CONCLUSIONS: Factors that are associated with an increased risk of mortality within thirty days after elective hip arthroplasty include an older age, male gender, and a history of cardiorespiratory disease. There has been a significant decline in the thirty-day mortality rate after elective hip arthroplasty in the last decade (p < 0.0002); during the 1990s, the overall rate at our institution was 0.15% (twenty-three of 14,989).     

Thermal response and torque resistance of five cortical half-pins under simulated insertion technique

A model was developed that can quantitate heat generation during placement of half-pins in cortical bone. Five half-pins were tested to assess differences in insertion torque, heat generation, and microdamage at the pin-bone interface. Thin thermocouple probes were placed 0.5 mm from the track of the pin and within the pin to measure its temperature during insertion. Scanning electron microscopy was used to view the pin-bone interface to assess the microdamage during placement. The design of the tip of the pin influenced insertion torque and heat generation. Higher heat generation was measured when a thermocouple was placed within the pin itself and less was measured when thermocouple probes were placed within bone samples 0.5 mm from the impending pin track. Furthermore, insertion torque and thermal responses were related, but there were no significant differences in microdamage to bone when different pins and drilling/tapping techniques were used. Due to the significant heat generation at the pin-bone interface, proper cooling with saline irrigation should be applied during pin insertion regardless of the design of the pin. The microdamage observed at the surface of the pin track may have significant implications with regard to loosening of pins, but such effects must be studied with in vivo models.     

Age-related hip fractures in men: Clinical spectrum and short-term outcomes

Clinical spectrum, treatment and short-term outcomes were assessed among the 131 Rochester, Minnesota, men who contracted an initial hip fracture due to moderate trauma during 1978–89. Three-fourths of falls leading to hip fracture occurred indoors with little seasonality, and 91% of fractures were in men 65 years of age or older. The ratio of cervical to intertro-chanteric femur fractures was 1.4:1, and there was a tendency toward more neurological conditions among the patients with cervical fractures. Hemiarthroplasty and total hip replacement were mostly performed for cervical fractures, while internal fixation was preferred for intertrochanteric fractures. In-hospital mortality was 11.5%, and the 30-day case fatality rate was 16.0%. Age and postoperative deterioration of mental status significantly increased the risk of early death, the latter even after adjustment in a multivariate model, while comorbidity had a suggestive but not statistically significant influence on mortality. More than half the men were discharged to nursing homes, and 79% of the patients who survived at 1 year resided in nursing homes or intermediate care facilities or were attended by home care. Only 41% of survivors recovered their prefracture level of functioning and nearly 60% of patients limped and required a cane or walker. After implementation of the prospective payment system in 1984, the length of hospital stay was reduced, but there was no change in early mortality rates, in the duration of physical therapy following fracture or in attendance at nursing homes. The results of this population-based study demonstrate the strong impact of hip fractures on short-term outcomes in men.