Allogeneic blood transfusion raised complication risk for THA

Procedure length and age also found to increase risk of postoperative complications.

WASHINGTON, D.C. — An analysis of almost 30,000 total hip replacements in Germany found that allogeneic blood transfusion significantly increased the postoperative complication risk. Lengthy procedures and older patients also produced higher complication rates in this cohort.

Researchers in Mannheim, Germany conducted a study based on data collected from one region of Germany from 2000 to 2002. The data set included 29,994 primary total hip replacements; 29,737 were available for full statistical analysis. Since 1996, hospitals in Germany have been required to collect anonymous patient- and procedure-related data on all THA operations.

“The majority of the procedures [were performed] using cementless fixation. More than 50% of the patients did not require any transfusion; about one-third required autologous transfusion and 15% required allogeneic transfusion. Only 3.3% required both,” said Alexandra M. Claus, MD, here at the American Academy of Orthopaedic Surgeons 72nd Annual Meeting.

Individual risk factors determined

Claus and colleagues used logistic regression to determine individual risk factors for postoperative complications, followed by univariate analysis to determine the influence of risk factors on each specific major complication. Finally, ANOVA analysis helped assess and quantify the influence of age and duration of surgery on complications.

“For the logistic regression, potential risk factors for postoperative complications were chosen from a clinical standpoint. They included patient-related factors, procedure-related factors such as qualification of the surgeon and time of surgery, as well as management related risk factors such as type of anesthesia or transfusion,” Claus said.

Patients had a mean age of 67.64 years, and mean duration of surgery was 81.93 minutes. Most patients received cementless implants.

Researchers found an overall major complication rate of 7.26%. Hematoma was the most common complication, occurring in 3.22% of patients, followed by cardiovascular complications (1.55%), joint infections (0.94%), neurovascular injuries (0.63%), DVT (0.37%), pneumonia (0.28%) and pulmonary embolism (0.26%).

Significant risk factors

“From the logistic regression, we found that age, regional anesthesia, allogeneic transfusion, time of surgery and fixation type were significant risk factors for suffering of postoperative complications,” Claus said. She noted that allogeneic blood transfusion increased risk the most, by 60%. Interestingly, epidural anesthesia actually decreased the risk for postoperative complications.

Allogeneic blood transfusions raised the cardiovascular complication risk 3.9-fold, which Claus said was “not surprising.” She noted that the transfusions also raised the infection risk by 3.17-fold.

Patients aged 70 and older also had an increased risk of general postoperative complications, and an increased risk for all specific complications except neurovascular injuries. Similarly, procedures taking longer than 78 minutes raised the risk of general complications and all specific complications except hematoma.

While the study has disadvantages — lack of clear definitions for all complications, underestimation of total complications, and lack of explanation for causal connections – it clearly shows that certain risk factors such as age, procedure length and allogeneic blood transfusion increase the chances of postoperative complications.

For more information:
Claus AM, Bosing-Schwenklengs M, Scharf HP. Risk-profiling in hip arthroplasty based on Perioperative complications of 29,994 hip replacements. #316. Presented at the American Academy of Orthopaedic Surgeons 72nd Annual Meeting. Feb. 23-27, 2005. Washington.