Published 5/1/2010

Second Look – Clinical News and Views

If you missed these Headline News Now items the first time around, AAOS Now gives you a second chance to review them. Headline News Now—the AAOS thrice-weekly, online update of news of interest to orthopaedic surgeons—brings you the latest on clinical, socioeconomic, and political issues, as well as important announcements from AAOS.

Suture closure may be safer than stapling
A review published online in the British Medical Journal finds a significantly higher risk for infection when a wound is closed with staples rather than with sutures after orthopaedic surgery, with the greatest risk to patients undergoing hip surgery. In six randomized and nonrandomized controlled trials covering 332 patients undergoing suture closure and 351 undergoing staple closure (some of which had major methodologic limitations), the risk of superficial wound infection after orthopaedic procedures was more than three times greater after staple closure. In a subgroup analysis of hip surgery alone, the risk of developing a wound infection was four times greater after staple closure. No significant differences between sutures and staples were found in the development of inflammation, discharge, dehiscence, necrosis, and allergic reaction.

Potential toxic effects of bupivacaine injection difficult to detect
A rat study published in the Journal of Bone & Joint Surgery—American (JBJS-A) suggests that any potential toxic effects of a single injection of bupivacaine may be difficult to detect clinically. The authors injected 48 Sprague-Dawley rats with 100 µL of sterile 0.9 percent saline solution (negative control) in one stifle joint and 100 µL of either preservative-free 0.5 percent bupivacaine (experimental group) or 0.6 mg/mL of monoiodoacetate (positive control) in the contralateral joint. Rats injected with bupivacaine had intact chondral surfaces under gross and histologic examination, and no differences in superficial chondrocyte viability or modified Mankin scores were observed between the saline-solution and bupivacaine groups at any location or time point (p > 0.05). At 6 months, however, quantitative histologic analysis of the bupivacaine-treated knees found up to 50 percent reduction in chondrocyte density compared with that of the saline-solution–treated knees (p = 0.01). Injection with monoiodoacetate resulted in death of up to 87 percent of superficial chondrocyte cells at one week and chondrolysis at 6 months.

Patient-reported height loss
According to a French study published online in the Canadian Medical Association Journal, vertebral fracture and thoracic kyphosis may be strong determinants of height loss among postmenopausal women. Researchers asked 1,779 randomly selected general practitioners to survey the first 5 female patients older than 60 years of age, regardless of the reason for the consultation. The patients were measured for height, as well as surveyed as to tallest recalled height in early adulthood and estimated current height. Among a cohort of 8,610 patients with a mean age of 70.9 years, the mean loss of height was 4.5 cm. The best predictors of a loss of height of 3 cm or more were age, previous vertebral fracture, previous nonvertebral fracture, thoracic kyphosis, scoliosis, back pain, and osteoporosis. The authors conclude that measurement of height loss could be an accurate method for detecting vertebral fractures.

Tissue-engineered bones hold promise
An article in the New York Times focused on growing replacement bones by using digital images to create a three-dimensional scaffold, placing the scaffold in a chamber molded to the exact shape, and adding human cells. The mold allows nourishment to penetrate the pores of the scaffold and enable the cells to grow within the pores, rather than on the outer surface of the scaffold.

HRT for OA?
A German study in Arthritis & Rheumatism (April) indicates that the use of sex hormones (testosterone in men and estrogen in women) may have a positive impact on the regenerative potential of cartilage tissue. An analysis of tissues samples from 372 total knee arthroplasty (TKA) patients found 17-beta estradiol in the joint fluid of all study participants and chondrogenic progenitor cells positive for both estrogen and androgen receptors. Both sex hormones influenced the expression of the receptor genes and regulated gene expression, leading researchers to hypothesize that hormone replacement in the synovial fluid might have beneficial effects on the regenerative potential of arthritic cartilage tissue.

Sliding hip screws for proximal femur fractures
A prospective, randomized, controlled trial of 210 patients presenting with an AO/OTA 31-A2 fracture of the proximal part of the femur finds that the sliding hip screw performs similarly to the long gamma nail, but at a lower cost. No significant difference was found between reoperation rates, quality of life outcome scores, mortality rates, or any secondary outcome measures for patients who received either sliding hip screws or long gamma nails. The study appeared in JBJS-A (April).

Deep infections after internal fixation
A study in JBJS-A (April) finds that surgical débridement, antibiotic suppression, and retention of hardware can be a successful approach to treatment of deep infection after internal fixation. A retrospective review of 121 patients with 123 postoperative wound infections from three centers found that 86 patients (87 fractures; 71 percent) had fracture union with surgical débridement, retention of hardware, and culture-specific antibiotic treatment and suppression. Open fracture and the presence of an intramedullary nail were predictors of treatment failure.

C. difficile infections increasing
Data presented at the 2010 International Conference on Healthcare-Associated Infections indicate hospital-onset, healthcare facility-associated Clostridium difficile infections may be more frequent and more severe than methicillin-resistant Staphylococcus aureus (MRSA). In a cohort study of patients at 30 community hospitals from Jan. 1, 2008, to June 30, 2009, researchers found 612 cases of C. difficile infection (0.26 cases/1,000 patient-days), 650 cases of bloodstream infection (0.28/1,000 patient-days), and 505 cases of infection due to MRSA (0.22/1,000 patient-days) during the 2,322,293 patient days within the study period. C. difficile infections were 21 percent more common than MRSA infections and approximately as common as bloodstream infections.

Leg-length inequality linked to risk of knee OA
According to a study in the Annals of Internal Medicine (March 2), radiographic leg-length inequality may be associated with knee osteoarthritis (OA). A prospective, observational cohort study of 3,026 participants aged 50 to 79 years who had knee OA or were at high risk for knee OA found that leg-length inequality of 1 cm or greater was associated with prevalent radiographic and symptomatic OA in the shorter leg and incident symptomatic OA in both legs.

Tendon integrity linked to fatty degeneration
A study in JBJS-A (April) finds that the integrity of the anterior supraspinatus tendon may be associated with fatty degeneration of rotator cuff muscles. Ultrasonograms of both shoulders of 262 patients with rotator cuff injury found 251 shoulders with full-thickness tears. Of those, 87 (34.7 percent) were found to have fatty degeneration in the supraspinatus, infraspinatus, or both. Additionally, 90 percent of the full-thickness tears with fatty degeneration in both muscles had a distance of 0 mm posterior from the biceps, whereas only 9 percent of those without fatty degeneration had a distance of 0 mm. Tears with fatty degeneration had significantly greater width and length and a significantly shorter distance posterior from the biceps than those without fatty degeneration. The distance posterior from the biceps was the most important predictor for supraspinatus fatty degeneration. Tear width and length were the most important predictors for infraspinatus fatty degeneration.

ASC ownership issues
According to a study in the April issue of Health Affairs, physician ownership of ambulatory surgery centers (ASCs) may be associated with higher surgical volume. The authors analyzed data collected by the state of Florida regarding five common surgical procedures and found that, on average, ASC owners operated on twice as many patients as non-owners. Additionally, although caseloads increased over time for all physicians, the increases were more rapid and dramatic among ASC owners.

In response, the Ambulatory Surgery Center Advocacy Committee states that “the study authors make inaccurate statements about the relationship between physician ownership of ASCs and higher surgical volume, inferring that physician owners are driven to refer patients to their facility by financial incentives. […] Volume is not a valid method for identifying which physicians have ownership interests in ASCs.”

FDA statement supports bisphosphonate use
The U.S. Food and Drug Administration (FDA) states that the agency has reviewed no data showing a clear connection between oral bisphosphonates and atypical subtrochanteric femur fractures. The FDA is working closely with outside experts, including members of the recently convened American Society of Bone and Mineral Research Subtrochanteric Femoral Fracture Task Force, to gather additional information that may provide more insight into this issue.

An FDA safety announcement states that “healthcare professionals should continue to follow the recommendations in the drug label when prescribing oral bisphosphonates,” and that patients should continue taking their medication unless recommended otherwise by their physician. The National Osteoporosis Foundation (NOF) supports the FDA position, saying that the benefits of bisphosphonates “outweigh the risks of these unusual but serious conditions that appear to be associated with them.”

Some physicians giving up on private practice
According to the New York Times, an increasing number of physicians are taking positions at hospitals and health systems instead of in private practice. Data from the Medical Group Management Association find that physicians owned more than two-thirds of medical practices in 2005, but less than half in 2008. The trend may be driven by a number of factors, including pressure to transition to expensive electronic medical records systems, concerns over medical liability and government reimbursement, high medical school debts, and a desire for stable work hours. A decline in private practice, however, may alter the enduring and intimate physician/patient relationships that have long been a part of medical practice.

Patient safety incidents not declining
According to the 7th Annual HealthGrades Patient Safety in American Hospitals Study, between 2006 and 2008, nearly 1 million total patient safety events occurred among Medicare beneficiaries, and approximately 1 in 10 Medicare patients who experienced an event died. In all, these incidents were associated with nearly $9 billion in excess costs. Postoperative sepsis ranked among the top 5 events. Of the indicators studied, six showed improvement and eight, including postoperative hip fractures, postoperative pulmonary embolism or deep venous thrombosis, and postoperative sepsis, worsened.

Use of complex back surgery rising
A study in the Journal of the American Medical Association (April 7) finds that the frequency of complex fusion procedures for spinal stenosis is increasing while the frequency of decompression surgery and simple fusions is decreasing. Both simple fusion and complex fusion are associated with increased risk of major complications, 30-day mortality, and resource use.

A retrospective cohort analysis of Medicare claims for patients who underwent surgery for lumbar stenosis between 2002 and 2007 found that overall surgical rates declined slightly, but the rate of complex fusion procedures increased from 1.3 per 100,000 beneficiaries in 2002 to 19.9 per 100,000 beneficiaries in 2007. Life-threatening complications increased with increasing surgical invasiveness, from 2.3 percent among patients having decompression alone to 5.6 percent among those having complex fusions. Adjusted mean hospital charges for complex fusion procedures were $80,888 compared with $23,724 for decompression alone.