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AAOS Now

Published 3/1/2017

Second Look-Clinical News and Views

Patient safety
These items originally appeared in AAOS Headline News Now, a thrice-weekly enewsletter that keeps AAOS members up to date on clinical, socioeconomic, and political issues, with links to more detailed information. Subscribe at www.aaos.org/news/news.asp (member login required)

TJA outcomes—Data from a study published in The Journal of Bone & Joint Surgery (JBJS; Jan. 4) attempts to develop risk-adjusted models for Medicare inpatient and post-discharge adverse outcomes in elective lower-extremity total joint arthroplasty (TJA). The authors reviewed information on 253,978 total hip arthroplasty (THA) patients and 672,515 total knee arthroplasty (TKA) patients from the Medicare Limited Data Set database. They found that the overall adverse outcome rates were 12.0 percent for THA and 11.6 percent for TKA. Z-scores for 1,483 hospitals performing THA varied from -5.09 better than predicted to +5.62 poorer than predicted, and the risk-adjusted adverse outcome rates were 6.6 percent for the best-decile hospitals and 19.8 percent for the poorest-decile hospitals. Z-scores for 2,349 hospitals performing TKA varied from -5.85 better than predicted to +11.75 poorer than predicted, and the risk-adjusted adverse outcome rates were 6.4 percent for the best-decile hospitals and 19.3 percent for the poorest-decile hospitals. The authors write that the “risk-adjusted outcomes demonstrate wide variability and illustrate the need for improvement among poorer performing hospitals for bundled payments of joint replacement surgical procedures.”

VTE prophylaxis—According to a study published in JBJS (Jan. 18), low-dose aspirin may not be inferior to high-dose aspirin for prevention of venous thromboembolism (VTE) following total joint arthroplasty (TJA). The research team reviewed data on 4,651 TJA patients, 3,192 of whom received enteric-coated 325-mg aspirin twice daily for 4 weeks and 1,459 of whom received 81-mg aspirin twice daily for 4 weeks. They found no significant difference between cohorts in incidence of VTE, gastrointestinal bleeding, or ulceration, and the 90-day mortality rate was similar in both groups. However, the incidence of acute periprosthetic joint infection was higher in the 325-mg aspirin group (0.2 percent vs. 0.5 percent).

Surgical site infection—The American College of Surgeons (ACS) and the Surgical Infection Society (SIS) have released new guidelines for the prevention, detection, and management of surgical site infection (SSI). Among other things, the guidelines note that control of high blood sugar prior to surgery may be more important than the presence of diabetes and use of diabetic medications, although both are still considered risk factors. In addition, the guidelines cite research that finds that smokers have the highest risk of SSI, and that former smokers are at greater risk of infection than nonsmokers.

OR bioburden—A study in Clinical Orthopaedics and Related Research (CORR; online) compares orthopaedic operating room (OR) surfaces contaminated with bioburden. The research team used adenosine triphosphate (ATP) bioluminescence technology to determine the degree of contamination of 13 surfaces in six orthopaedic ORs that had been cleaned and prepped for surgery, but prior to patients entering the room. They found that all tested surfaces had bioburden. Surfaces with the greatest bioburden included (in descending order) the right side of the OR table headboard, computer keyboard, tourniquet machine buttons, Bair Hugger™ buttons, Bovie machine buttons, and patient positioners used for total hip and spine positioning. The research team writes that the study did not examine correlation between ATP bioluminescence and clinical infection.

Bone cancerFindings in The Journal of the American Medical Association (Jan. 3) suggest that longer intervals between treatments with zoledronic acid may not be linked to an increased risk of short-term skeletal events among patients with bone metastases due to breast cancer, prostate cancer, or multiple myeloma. The authors conducted a randomized, open-label clinical trial of 1,822 patients with breast cancer, metastatic prostate cancer, or multiple myeloma who had at least one site of bone involvement and who were randomized to receive intravenous zoledronic acid every 4 weeks (n = 911) or every 12 weeks (n = 911). At 2-year follow-up, they found that 260 patients in the 4-week cohort and 253 patients in the 12-week cohort had experienced at least one skeletal-related event. In addition, there was no significant difference across cohorts in pain scores, performance status scores, incidence of jaw necrosis, or kidney dysfunction. The authors write that skeletal morbidity rates were numerically identical in both groups, but bone turnover was greater among patients in the 12-week cohort.

Foot and ankle
Outpatient TAA
—According to a study in Foot & Ankle International (online), outpatient total ankle arthroplasty (TAA) may be a cost-effective and safe alternative to inpatient TAA. The researchers retrospectively reviewed data on 36 TAA patients, 21 of whom were treated as outpatients. They found that the average length of stay for the inpatient group was 2.5 days, and the overall cost differential between the groups was 13.4 percent—a savings of nearly $2,500 per case. There were no 30-day readmissions in either group, although one patient in the outpatient cohort presented for urinary retention to the emergency department on postoperative day 1. Overall, 71 percent of the outpatient group and 93 percent of the inpatient group stated that they would not change to a different postoperative admission status if they were to have the procedure again.

Spine
LDP and LBP
—According to study in The Spine Journal (February), interlaminar epidural steroid injections may help reduce pain for patients with multilevel lumbar disk pathology (LDP) and chronic low back pain (LBP). The research team conducted a randomized, controlled trial of 98 patients with multilevel LDP who received either 10 mL 0.25% bupivacaine or 10 mL 0.25% bupivacaine plus 40 mg methylprednisolone. All treatments were administered at the L4–L5 intervertebral space in prone position under the guidance of C-arm fluoroscopy. At 1-, 3-, 6-, and 12-month follow-up, they found that visual analog scale and Oswestry Disability Index scores were higher in the anesthetic-only group, compared with the anesthetic plus steroid group. The research team writes that “further studies are required to establish a robust conclusion on the dispersion of [interlaminar] epidural injections in the epidural area and the dose of steroid.”

Spine procedures—A study in CORR (online) compares the rate of certain spinal procedures under performed under a fee-for-service (FFS) system and in Department of Defense (DOD) facilities. The research team reviewed information on 28,344 patients who were surgically treated for lumbar disk herniation, spinal stenosis, or spondylolisthesis, 21,290 of whom were treated at a civilian facility with expenses covered by TRICARE insurance and 7,054 of whom were treated in Department of Defense facilities. They found that TRICARE beneficiaries treated for lumbar spinal disorders in the fee-for-service setting were 1.25 times as likely to receive interbody fusions. Overall, purchased care patients were more likely to receive interbody fusions for a diagnosis of disk herniation and for spinal stenosis. The research team noted no difference for patients with spondylolisthesis.

Hip
Periprosthetic infection
—A study in The Journal of Arthroplasty (online) attempts to identify organisms associated with poor outcomes in treatment for hip periprosthetic infection. The authors reviewed records of patients who underwent treatment for infected partial or total hip arthroplasty between 2005 and 2015. They found that, compared with patients infected with other organism(s), patients infected with Pseudomonas, methicillin-resistant Staphylococcus aureus (MRSA), and Proteus had significantly decreased infection-free rates. In addition, infection with the following certain organisms was associated with 1.13 to 2.58 additional surgeries: methicillin-sensitive Staphylococcus aureus (MSSA), coagulase-negative Staphylococcus (CoNS), MRSA, Pseudomonas, Peptostreptococcus, Klebsiella, Candida, diphtheroids, Propionibacterium acnes, and Proteus species. Finally, the following organisms were associated with 8.56 to 24.54 additional days in hospital for infection: MSSA, CoNS, Proteus, MRSA, Enterococcus, Pseudomonas, Klebsiella, beta-hemolytic Streptococcus, and diphtheroids.

Outpatient THAData published in CORR (February) suggest that outpatient THA may be safe and effective for certain patients. The researchers conducted a prospective, randomized study of 220 THA patients at two centers, 112 of whom were treated as outpatients and 108 of whom were treated as inpatients. They found that, of 112 patients randomized to outpatient surgery, 85 (76 percent) were discharged as planned, while 26 were discharged after one night in the hospital, and one was discharged after two nights. Of the 108 patients randomized to inpatient surgery with an overnight hospital stay, 81 (75 percent) were discharged as planned, 18 met discharge criteria on the day of their surgery and elected to leave the same day, and nine stayed two or more nights. On the day of surgery, the researchers noted no difference in visual analog scale (VAS) pain among patients randomized to same-day discharge or overnight stay. However, on the first day after surgery, outpatients had higher VAS pain than inpatients. Overall, the researchers found no difference between cohorts in number of reoperations, hospital readmissions without reoperation, emergency department visits without hospital readmission, or acute office visits. In addition, at 4-week follow-up, they found no difference in number of phone calls and emails with the surgeon’s office.

Knee
ACL reconstruction
Findings in The American Journal of Sports Medicine (online) compares outcomes for patients who undergo anterior cruciate ligament (ACL) reconstruction and surgical or nonsurgical treatment of stable ramp lesions of the medial meniscus. The authors conducted a randomized, controlled trial of 91 consecutive patients with complete ACL injuries and concomitant stable ramp lesions of the medial meniscus. During ACL reconstruction, 50 patients underwent surgical repair of the stable ramp lesions and 41 were treated with abrasion and trephination alone. Among 73 patients available with minimum 2-year follow-up, the authors found no significant difference across cohorts in mean Lysholm score, mean subjective International Knee Documentation Committee score, pivot-shift test results, Lachman test results, KT-1000 arthrometer side-to-side difference, or KT-1000 arthrometer grading. In addition, at final follow-up, the authors found no significant difference between groups in healing status of the ramp lesions.

Supplements—According to data published in the journal Arthritis & Rheumatology (January), combination therapy with chondroitin sulfate (CS) and glucosamine sulfate (GS) may not be superior to placebo for the treatment of symptomatic knee osteoarthritis (OA). The authors conducted a randomized, double-blind, placebo-controlled trial of 164 patients with Kellgren/Lawrence grade 2 or grade 3 radiographic knee OA and moderate-to-severe knee pain. Patients received a 6-month course of treatment consisting of a single, oral, daily dose of placebo or combined treatment with CS (1,200 mg) and GS (1,500 mg). In a modified intent-to-treat population, they found that CS/GS combination therapy was inferior to placebo in the reduction of joint pain, but found no between-group differences in per-protocol completers. Overall, both placebo treatment and CS/GS combination treatment improved to a similar extent the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores and function WOMAC subscale scores.

Shoulder and elbow
Rotator cuff disease
—Findings published in CORR (online) cast doubt on the relationship of critical shoulder angle (CSA) to rotator cuff disease. The researchers retrospectively compared data on 313 patients with asymptomatic rotator cuff tear who underwent ultrasonography and standardized anteroposterior radiographs at enrollment and yearly thereafter during a median of 4 years. Of 1,552 radiographs evaluated, they found that 326 (21 percent) were of sufficient quality to measure CSA. The researchers noted that CSA was higher among patients with cuff tears than control patients, but CSA did not correlate with baseline tear length or width, and CSA was not different between tears that enlarged and those that were stable. In addition, CSA did not change over time.

Clavicle fracture—According to a study published in JBJS (Jan. 18), certain patients with a diaphyseal fracture of the clavicle may be more likely to heal when treated with plate fixation than nonsurgical treatment. The authors conducted a randomized, controlled trial of 160 patients aged 18 to 60 years who were treated with open reduction with internal plate fixation or nonsurgically. At 1-year follow-up, they found that the rate of nonunion was significantly higher in the nonsurgical cohort compared to the plate fixation cohort. They note that the rate of secondary operation was 27.4 percent in the surgical group (16.7 percent for elective plate removal) and 17.1 percent in the nonsurgical group. Overall, 19 percent of patients in the surgical group had persistent loss of sensation around the scar. The authors found no difference across cohorts with respect to Constant shoulder and Disabilities of the Arm, Shoulder and Hand scores at any time point.

Fracture
Bisphosphonates
—A position paper presented by the International Osteoporosis Foundation and the European Calcified Tissue Society recommends measuring bone turnover markers Procollagen I intact N-terminal Propeptide (PINP) and C-terminal telopeptide (CTX) at baseline and 3 months after starting oral bisphosphonate therapy to identify patients with low adherence to treatment. The writers cite data from the TRIO study specifically addressing the question of adherence and recommend that clinicians check for a decrease above the least significant change (decrease of more than 38 percent for PINP and 56 percent for CTX). “If a significant decrease is observed,” they write, “the treatment can continue, but if no decrease occurs, the clinician should reassess to identify problems with the treatment, mainly low adherence.”

Menopause—A study published in the Journal of Bone and Mineral Research (online) suggests that areal bone mineral density (aBMD) may not predict bone changes for women transitioning through menopause. The research team analyzed hip dual-energy X-ray absorptiometry images acquired longitudinally over 14 years for 198 mid-life women who were transitioning through menopause. They observed a 14-year change in bone mineral content (BMC) and bone area, but not aBMD, across tertiles based on baseline bone area-height residuals. The research team found that women with narrow femoral necks showed smaller changes in BMC “but greater increases in bone area compared to women with wide femoral necks who showed greater losses in BMC but without large compensatory increases in bone area.” They note that the finding is “opposite to expectations that periosteal expansion acts to mechanically offset bone loss. Thus, changes in femoral neck structure and mass during menopause vary widely among women and are predicted by baseline external bone size but not aBMD.”