AAOS Now

Published 7/1/2011

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.

ALTR uncommon after MOM hip resurfacing
According to a study in the Journal of Bone & Joint Surgery—American (May 4 supplement), adverse local tissue reactions (ALTRs) are uncommon after metal-on-metal (MOM) hip resurfacing. A survey of nine centers covering 3,432 MOM hip resurfacing arthroplasties found four ALTRs at mean 3.4-year follow-up (range 2 to 9 years), for a prevalence of 0.10 percent. The reactions remain a concern and MOM hip resurfacing patients should be monitored.

Diabetes patients and fracture risk
A study in the Journal of the American Medical Association (June 1) on the relationship between femoral neck bone mineral density (BMD) T score, World Health Organization Fracture Risk Algorithm (FRAX) score, and fracture risk in diabetes mellitus (DM) patients, based on data from 9,449 women and 7,436 men who participated in three prospective observational studies with adjudicated fracture outcomes, found that, of 770 women with DM, 84 experienced a hip fracture and 262 had a non-spine fracture during a mean follow-up of 12.6 years. Of 1,199 men with DM, 32 experienced a hip fracture and 133 had a non-spine fracture during a mean follow-up of 7.5 years. FRAX score was associated with fracture risk in participants with DM.

Bariatric surgery and fracture risk
Data presented at the annual meeting of the Endocrine Society suggest that patients who have undergone bariatric surgery are at increased risk of fracture. The retrospective study of fracture incidence in 277 patients who underwent a first bariatric surgery between 1985 and 2004 at a single center found that, following bariatric surgery, 82 patients sustained a total of 138 fractures, with a mean time to first fracture of 5.9 years (range, 0.2 to 18.6 years). The standardized incidence ratio (SIR) for any fracture was 2.1. The SIR for a first fracture at hip, wrist, spine, or humerus was 1.9, compared to 2.3 (CI, 1.8 to 2.9) for a first fracture at all other sites.

Prostate cancer drug shows promise against bone tumors
Information from a paper presented at the annual meeting of the American Society of Clinical Oncology suggests that the anti-cancer drug cabozantinib may reduce tumor growth in men with metastatic prostate cancer. The trial enrolled 171 men with metastatic prostate cancer, more than three quarters of whom had bone metastases. Tumors shrank in 76 percent of patients treated with cabozantinib. Among patients who were on narcotics because of bone pain, 67 percent reported less pain and 56 percent either stopped taking narcotics or reduced the dosage.

Asymptomatic FAI and OA
A study published in the Journal of Bone & Joint Surgery–British (May) suggests that the risk of developing osteoarthritis (OA) may not be as high as expected for patients with femoroacetabular impingement (FAI). The retrospective examination of 96 asymptomatic hips in 96 patients with a mean age of 49.3 years (range 16 to 65 years) who had radiological evidence of FAI found that overall, 79 hips (82.3 percent) remained free of OA for a mean 18.5 years (range 10 to 40 years). OA developed in 17 hips (17.7 percent) at a mean of 12 years (range 2 to 28 years). No statistically significant difference was found in the rates of development of osteoarthritis among groups of patients identified with cam, pincer, or mixed impingement. Only the presence of idiopathic osteoarthritis of the contralateral diseased hip was predictive of osteoarthritis developing on the asymptomatic side.

TEA injection may reduce blood loss after minimally invasive TKA
A study in Clinical Orthopaedics and Related Research (July) suggests that a single intraoperative injection of tranexamic acid (TEA) may decrease total blood loss after minimally invasive total knee arthroplasty (TKA). The prospective study involved 100 patients who underwent minimally invasive TKA, 50 who received one intravenous TEA injection before deflation of the tourniquet, and 50 who received an equivalent volume of placebo. Both total blood loss and rate of blood transfusion were less for patients in the TEA group than for patients in the control group.

Smoking and clogged leg arteries
According to a study in the Annals of Internal Medicine (June 7), smoking is a potent risk factor for symptomatic peripheral artery disease (PAD). The prospective cohort study involved 39,825 women with no cardiovascular disease who were followed for a median of 12.7 years. Among all patients, there were 178 confirmed PAD events. Age-adjusted incidence rates increased across 4 smoking categories (never, former, fewer than 15 cigarettes per day, and 15 or more cigarettes per day). Additionally, lifetime exposure to cigarette smoke showed a strong dose-response relationship.

Obese patients at greater risk of SSI
Obese patients are at greater risk of developing a surgical site infection (SSI), according to a study in Archives of Surgery (online). The retrospective cohort study of 7,020 patients who underwent total or segmental colectomy for colon cancer, diverticulitis, or inflammatory bowel disease between Jan. 1, 2002, and Dec. 31, 2008 found that obese patients had an increased rate of SSI compared with nonobese patients. Independent risk factors for infections were obesity and open operation (as compared with a laparoscopic procedure). The mean total cost was $31,933 in patients with infection, while the mean total cost for patients without infection was $14,608.

Effectiveness of low-dose zoledronate
According a paper presented at the annual meeting of the Endocrine Society, zoledronic acid may improve bone mineral density (BMD) at lower doses than are commonly used in clinical practice. The randomized trial involved 180 osteopenic postmenopausal women who were allocated to receive a single dose of placebo or 1 mg, 2.5 mg, or 5mg of intravenous zoledronate. At 12-month follow-up, the change in spine BMD and hip BMD was significantly greater for participants in each experimental group, compared to those in the placebo group. The findings also suggest that annual administration of doses of intravenous zoledronate of either 1 mg or 2.5 mg may produce substantial anti-resorptive effects that approximate those of a 5 mg dose, and that such doses may confer significant anti-fracture efficacy.

Variation in cost of spinal fusion
A study in Spine (May 15) finds wide variation in total hospital charges for performing single-level anterior cervical diskectomy/fusion (1-ACDF). A review of hospital charge information from 102 patients undergoing 1-ACDF procedures with no comorbidities at a single institution found that the total hospital charges per patient ranged from $26,653 to $129,220. Inpatient hospital charges ranged from $15,113 to $76,687 and were largely influenced by differing lengths of stay (range 1–11 days). Surgical charges varied, largely because of the choice of instrumentation; instrumentation charges per patient ranged from $4,062 to $40,409.