The 2012 annual meeting of the American Academy of Orthopaedic Surgeons was held from February 7-11 in San Francisco. The features below highlight just some of the studies that emerged from the meeting.

>> Analyzing Deep SSIs in Total Hip Arthroplasty
>> Pain Following TKA Tied to Osteoarthritis
>> Are Antibiotics Necessary for Clean Soft Tissue Hand Surgery?
>> Defensive Medicine Costly in Orthopaedic Surgery
>> Trending Lumbar Spinal Stenosis Surgery

Analyzing Deep SSIs in Total Hip Arthroplasty

The Particulars: Deep surgical site infections (SSIs) are severe complications that may occur in total hip arthroplasty (THA). Few studies have explored patient- and surgical-related risk factors for SSIs associated with THA.

Data Breakdown: A prospective cohort study of 30,491 THA procedures found an incidence rate of 0.51% for deep SSIs. Patient factors associated with deep SSI were female gender, BMI of 30 kg/m2 or higher, and American Society of Anesthesiologist risk score of 3 or greater. Patient factors not associated with an increased risk of SSIs were age, arthritis diagnosis, diabetes, and race. Bilateral THA procedures were associated with a 5.32-times increased risk of SSIs when compared with unilateral THA procedures. Surgeon and hospital case volumes, use of antibiotic cement, fixation method, laminar flow, surgical approach, and fellowship training were not associated with SSIs.

Take Home Pearl: Female gender, obesity, chronic medical conditions, and bilateral THA procedures appear to be associated with deep SSIs.

Pain Following TKA Tied to Osteoarthritis

The Particulars: Little is known regarding the association between objective ratings of preoperative osteoarthritis (OA) and pain and dissatisfaction following total knee arthroplasty (TKA).

Data Breakdown: In a study, investigators found that the incidence of preoperative early-grade OA among patients with painful TKA of unknown etiology was significantly higher (49.0%) than that of three groups of matched cohorts with radiographically normal TKAs. These three groups consisted of a consecutive series of primary TKAs (5.5%), patients who were asymptomatic at 1 to 4 years (6.3%), and those with some degree of pain at 1 to 4 years (10.0%). Patients who were asymptomatic were more likely to have preoperative Grade 4 OA than those with some degree of pain at follow-up.

Take Home Pearls: Many patients who are referred for unexplained pain following TKA appear to have early-stage preoperative OA. Patients who are scheduled for TKA for less than Grade 4 OA should be informed of their higher risk for persistent pain and dissatisfaction after surgery.

Are Antibiotics Necessary for Clean Soft Tissue Hand Surgery?

The Particulars: Data regarding the necessity of antibiotics in common, elective hand procedures are lacking. Research on hand procedures has mostly focused on traumatic hand surgery and carpal tunnel release. Indications for prophylactic antibiotics in clean soft tissue hand surgery have not been well defined in studies.

Data Breakdown: A review of 635 consecutive elective soft tissue hand procedures found that the overall infection rate for these surgeries was 0.90%. All infections were deemed superficial. The infection rate was 1.29% among those who received prophylactic antibiotics, compared with 0.75% for those who did not. Tenolysis surgery was 8.46 times more likely to result in an infection than other procedures, including carpal tunnel release, trigger finger release, mass excision, and first dorsal compartment release.

Take Home Pearls: Following elective soft tissue hand surgery, overall rates of infection appear to be low. Antibiotics do not appear to provide additional protection from surgical site infections. Routine administration of antibiotics in this setting may not be warranted, but more research is necessary.

Defensive Medicine Costly in Orthopaedic Surgery

The Particulars: Defensive medicine is a practice used in an effort to exonerate physicians from malpractice liability. Research suggests defensive medicine oftentimes leads to poor management of patients. Studies have argued that such practices are a major cost driver in healthcare, but research is needed on the prevalence of defensive medicine in orthopaedic surgery.

Data Breakdown: A web-based survey was administered to randomly selected orthopaedic surgeons, 1,214 of whom responded. The vast majority of respondents (96%) reported having practiced defensive medicine, consisting of ordering imaging, laboratory tests, specialist referrals, or hospital admissions mostly to avoid possible malpractice liability. The estimated average cost of defensive medicine per respondent was $8,500 monthly, or roughly $100,000 annually. Study authors estimated that the national cost of defensive medicine among orthopaedic surgeons was $173 million per month and $2 billion per year.

Take Home Pearl:The practice of defensive medicine among orthopaedic surgeons appears to be a significant contributor to healthcare costs.

Trending Lumbar Spinal Stenosis Surgery

The Particulars: The number of surgeries performed for lumbar spinal stenosis (LSS) has increased significantly in the last several decades. There has been controversy, however, over which type of LSS surgery should be performed for patients with certain characteristics.

Data Breakdown: In a data review, researchers found that the annual number of inpatient discharges with a primary diagnosis of LSS increased from 91,630 in 2004 to 101,936 in 2008. While the proportion of patients aged 45 to 65 with LSS increased from 31.7% to 34.2%, proportions decreased for all other age groups. Surgical decompression alone was used for 53.1% of patients with LSS in 2004, compared with 43.7% in 2008. Rates for spinal fusion were 24.5% in 2004 but increased to 34.2% in 2008. For patients who required fusion in 2004 and 2008, hospital stays decreased from 4.60 days to 3.95 days, respectively. Mortality for LSS patients requiring fusion decreased from 0.3% to 0.1%, and average hospital charges increased from $52,996 to $84,032, respectively.

Take Home Pearls: The proportion of LSS cases that require fusion appears to have increased between 2004 and 2008, while surgical decompression use decreased. During this period, the average hospital charges for fusion increased by 56.8%.


For more information on these studies and others that were presented at the 2012 annual meeting of the American Academy of Orthopaedic Surgeons, go to