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AAOS Now

Published 5/1/2018

Second Look – Clinical News and Views

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).

Spine
Nonopioid regimen—
A study in The Journal of the American Medical Association (JAMA; March 6) suggests that opioids may not be superior to nonopioid medications for moderate to severe chronic back pain or hip or knee osteoarthritis (OA) pain. The authors conducted a pragmatic, randomized trial with masked outcome assessment of 234 patients. Patients in the opioid cohort were first prescribed immediate-release morphine, oxycodone, or hydrocodone/acetaminophen. Patients in the nonopioid cohort were first prescribed acetaminophen or an NSAID. In both cohorts, medications were changed, added, or adjusted based on individual patient response. Over 12 months, the authors found that groups did not significantly differ on pain-related function. However, pain intensity was significantly better in the nonopioid group, while adverse medication-related symptoms were significantly more common in the opioid group.

Chronic opioid therapy—Data published in Spine (online) suggest that preoperative chronic opioid therapy may increase risk of complication and adverse events following primary one- to two-level posterior lumbar fusion (PLF) for degenerative spine disease. Members of the research team reviewed information on 24,610 patients (mean age 65.6 years), of whom 5,500 (22.3 percent) had documented opioid use for more than six months prior to surgery. After adjustment, they found that preoperative chronic opioid therapy was associated with an increased risk of 90-day wound complications, pain diagnoses, emergency department visits, readmission, and continued use postoperatively. In addition, long-term opioid users displayed an increased utilization of epidural/facet joint injections, risk for revision fusion, and increased incidence of new onset constipation within one-year postsurgery.

Multilevel laminectomy—Findings presented at the AAOS 2018 Annual Meeting suggest that some patients who undergo spinal decompression of three or more consecutive levels without concomitant fusion may not require subsequent arthrodesis. The researchers reviewed data on 45 patients who underwent multilevel (three or more) lumbar decompressions without concomitant fusion at a single tertiary referral hospital and who had at least 11 months of follow-up. They found that three patients (7 percent) went on to subsequent arthrodesis at a previously decompressed level at mean 21 months, three patients (7 percent) underwent revision decompression at previously decompressed levels at mean 53 months, and one patient with follow-up greater than 100 months underwent revision decompression at 130 months.

Vancomycin powder—A preliminary study published The Journal of Bone & Joint Surgery (JBJS; March 21) suggests that vancomycin powder may be effective for reducing risk of surgical site infection (SSI) following surgery for early-onset scoliosis, even when previous surgeries have been performed without it. Members of the research team performed a retrospective study of 36 patients who underwent 191 procedures for early-onset scoliosis. During the study period, they found that 14 patients (39 percent) developed one or more deep SSI, and two patients had multiple acute infections. The researchers noted 87 procedures with 12 infections in the control cohort (13.8 percent SSI rate per procedure) and 104 procedures with five infections in the vancomycin cohort (4.8 percent SSI rate per procedure).

Shoulder and elbow
Propionibacterium load—
According to a study in the Journal of Shoulder and Elbow Surgery (online), a culture of unprepared skin taken preoperatively may help predict Propionibacterium load among revision shoulder arthroplasty patients. The authors conducted a prospective study of 60 patients without clinical evidence of infection. They took a preoperative culture of each patient’s skin surface prior to skin preparation, along with multiple deep tissue and explant cultures at the time of surgery. Based on multivariate analysis, the authors found that preoperative specimen Propionibacterium value was predictive of Propionibacterium load in the revised shoulders as indicated by total and averaged shoulder Propionibacterium score.

Complication risk—Findings published in the Journal of the AAOS (April 1) suggest that discharge to a postacute care (PAC) facility may be an independent risk factor for complication and readmission after shoulder arthroplasty. Members of the research team reviewed information on 10,660 shoulder arthroplasty procedures from the California Office of Statewide Health Planning and Development discharge database. They found that 7,709 patients were discharged home, 1,858 were discharged home with home health support, and 1,093 were discharged to PAC facilities. Overall, patients discharged to PAC facilities or to home with health support tended to be older, female, and using Medicare. However, after controlling for confounders, the researchers found that patients who were discharged to PAC facilities were found more likely to experience a complication at 30- and 90-day follow-ups.

Foot and ankle
Casting vs. surgery—A research letter published in JAMA (March 27) suggests that close contact casting or surgical treatment of unstable ankle fracture may offer equivalent ankle function for older adults. The authors conducted a randomized clinical trial of 428 patients older than 60 years, 206 of whom were treated with casting and 222 of whom were treated with surgery. At median three-year follow-up, they found no significant difference across cohorts in Olerud and Molander Ankle Score, quality of life, or pain. Overall, 17 patients in the casting cohort (8 percent) and 22 patients in the surgical cohort (10 percent) underwent surgery after six months. Five patients in the casting group underwent internal fixation for nonunion after six months. In post hoc analysis, the authors found that the mean total operating room procedures per participant (per protocol) were 1.3 in the casting group and 1.2 in the surgery group, while mean total surgical procedures per participant were 0.3 in the casting group and 1.2 in the surgery group.

Hand and wrist
Anesthesia preference—According to research presented at the AAOS 2018 Annual Meeting, patients who undergo staged bilateral carpal tunnel release (CTR) may be equally satisfied with outcomes regardless of method of anesthesia. The researchers conducted a prospective, randomized, controlled trial of 48 patients aged 18 years or older who were scheduled to undergo staged bilateral CTR. Of 27 patients who completed the study, 26 (96 percent) reported they were equally satisfied with their outcome whether they were treated with local anesthesia only or local anesthesia plus sedation. However, the researchers found that wide-awake CTR with local-only anesthesia was preferred by 59 percent of patients, while sedation was preferred by 33 percent of patients.

Hip
THA complication trend—
A study conducted in the United Kingdom and published in JBJS (March 7) examines complication trends following total hip arthroplasty (THA). The researchers reviewed data on 540,623 THAs performed between January 2005 and July 2014. They found that the overall 90-day mortality rate fell over the term of the study from 0.60 percent to 0.15 percent, and reported postoperative complications (except for lower respiratory tract infection and renal failure) fell each year, despite a steady increase in the average Charlson Comorbidity Index score. However, the researchers state that the 30-day rate of lower respiratory tract infection increased from 0.54 percent to 0.84 percent and the 30-day rate of renal failure increased from 0.21 percent to 1.09 percent. They note that the observed risk of mortality was significantly higher in patients with those two conditions than for patients who developed pulmonary embolism or deep-vein thrombosis (DVT).

Revision THA trend—According to data in JBJS (March 21), the rate of revision THA significantly increased among patients 45 to 64 years of age from 2007 to 2013. The authors reviewed data on 320,496 THA revisions performed from 2007 through 2013 and found that, after adjustment for population growth, the THA revision rate increased by 30.4 percent among patients 45 to 64 years of age, while it decreased in all other age groups. Overall, the rate of surgically treated THA dislocations decreased 14.3 percent during the term of the study. The authors note that the mean length of hospital stay and hospital costs for THA revision were significantly lower in 2013 compared to 2007, and the risk of complications such as DVT, pulmonary embolism, myocardial infarction, transfusion, pneumonia, urinary tract infection, and mortality fell significantly from 2007 to 2013.

Cobalt and chromium levels—Assessment of synovial fluid levels for cobalt and chromium at the time of aspiration may help identify THA patients who are most at risk for failure or adverse local tissue reaction (ALTR), according to a study presented at the AAOS 2018 Annual Meeting. Members of the research team prospectively collected synovial, blood, and serum samples from 58 revision THA patients, 29 of whom had an adverse reaction to metal debris (ARMD) and a matched cohort of 29 patients who underwent aseptic revision without ARMD. At time of revision, the researchers found that cobalt and chromium levels were significantly elevated in patients with an ARMD compared to those in the non-ARMD group. They also found that synovial fluid cobalt levels were an accurate test for detecting pseudotumor and ALTR.

Life expectancy—A study conducted in Sweden and published in Clinical Orthopaedics and Related Research (online) suggests that elective THA may be associated with a slight increase in life expectancy for approximately 10 years after surgery, especially among patients whose diagnosis was primary OA. The authors reviewed data on 131,808 patients from the Swedish Hip Arthroplasty Register, of whom 21,755 had died at final follow-up. They found that at one year after surgery, survival in patients undergoing THA was 1 percent better than the expected survival of a matched cohort from the general population. At five years, improved survival increased to 3 percent; at 10 years, the difference was 2 percent; and at 12 years, there was no difference. The authors write that patients who underwent surgery for osteonecrosis of the femoral head, inflammatory arthritis, or secondary OA all had poorer relative survival compared to the general population. Comorbidities and the Elixhauser comorbidity index also displayed a negative association with relative survival.
THA failure—Patients who must return to the operating room for mechanical failure after THA—especially in the first two weeks after surgery—may be at increased risk of infection or wound complication requiring a subsequent operation, according to a paper presented at the AAOS 2018 Annual Meeting. Members of the research team conducted a retrospective study of 16,203 primary THA patients from a single institution and found that patients who underwent surgery for mechanical failure within 14 days after the initial THA had the highest rate of subsequent infection and wound complications, nearly five times higher than that of patients who had revision surgery 90 days or more after primary THA.

Knee
Collagen membrane—
Data in The American Journal of Sports Medicine (online) suggest that treatment with autologous cultured chondrocytes on porcine collagen membrane (MACI) may be more effective than microfracture for the treatment of symptomatic cartilage defects of the knee. The authors conducted a randomized, controlled trial of 128 patients with symptomatic cartilage defects of 3 cm2 or larger, 65 of whom were treated with MACI and 63 of whom were treated with microfracture. At five-year follow-up, they found that patients in the MACI cohort displayed significant improvement in Knee Injury and Osteoarthritis Outcome Score (KOOS) pain and function domains compared to patients in the microfracture cohort. In addition, improvements in activities of daily living were statistically significantly better in MACI patients, and quality of life and other symptoms remained numerically higher in MACI patients but lacked statistical significance compared to a similar analysis at two-year follow-up.

OCA transplantation—According to data presented at the American Orthopaedic Society for Sports Medicine Specialty Day meeting, osteochondral allograft (OCA) transplantation with dowel-type grafts may be effective for treatment of certain isolated femoral condyle cartilage lesions. Members of the research team reviewed information on 187 patients (200 knees) who underwent OCA transplantation for isolated cartilage lesions on the femoral condyle. A single graft was used in 145 knees (72.5 percent) and two grafts were used in 55 knees (27.5 percent). At mean 6.7-year follow-up (range: 1.9 to 16.5 years), they found that International Knee Documentation Committee scores improved from 5.5 to 2.7 for pain, 3.4 to 7.3 for function, and 43.7 to 76.2 for total score. Similarly, KOOS for pain improved from 66.5 to 85.3 and activities of daily living score improved from 74.5 to 91.1. Overall, 89 percent of patients reported satisfaction with their outcomes. The researchers note that further surgery was required in 52 knees (26 percent), of which 16 knees (8 percent of total cohort) were defined as OCA failures. Median time to failure was 4.9 years (range: 0.3 to 16.1 years). OCA survivorship was 95.6 percent at 5 years and 91.2 percent at 10 years.

Geniculate artery embolization—Findings from a pilot study (abstract #210) presented at the annual scientific meeting of the Society of Interventional Radiology suggest that geniculate artery embolization (GAE) may help reduce pain and disability for patients with mild to moderate knee OA. The researchers performed GAE using 75 µm or 100 µm microspheres in 13 patients with median baseline OA of Kellgren Lawrence stage III. They found that GAE was technically successful in all patients. At one-month follow-up, the researchers noted significantly improved visual analog scores and decreased global Western Ontario and McMaster Universities Osteoarthritis Index score. They identified no major adverse events related to the procedure.

Fracture
Gastric bypass surgery risk—
According to research presented at the annual meeting of the Endocrine Society, patients who undergo Roux-en-Y gastric bypass (RYGB) surgery may be at increased risk of nonvertebral fracture compared to those who undergo adjustable gastric banding (AGB) surgery. Members of the research team analyzed Medicare billing claims data for 50,649 adults, of whom 35,920 underwent RYGB and 14,729 underwent AGB. They found that 1,109 nonvertebral fractures were reported during follow-up. The estimated incidence rates of nonvertebral fractures per 1,000 person-years were 9.8 in the RYGB group and 7.1 in the AGB group. The researchers note that RYGB patients were younger than AGB patients and more likely to have diabetes and a shorter average follow-up time. However, age and diabetes status did not affect RYGB-associated fracture risk.

Tibial plateau fracture—Data published in the Journal of the AAOS (March 15) suggest no difference in functional outcomes whether patients are braced or not braced following open reduction and internal fixation (ORIF) of tibial plateau fracture. The authors conducted a prospective, comparative trial of 49 patients, 24 of whom were treated with bracing after ORIF and 25 of whom were not. They found no significant difference in most functional, subjective, and radiographic outcomes, including fracture characteristics, complications, postoperative range of motion, Medical Outcomes Study 36-Item Short Form scores, and union rates. The authors write that one patient in the nonbraced cohort had late joint collapse with valgus malalignment. In addition, two wound complications occurred in the braced group and four wound complications occurred in the nonbraced group, but the difference was not statistically significant.

Malnutrition and hip fracture—According to research published in the Journal of Orthopaedic Trauma (April), malnutrition identified by increasing severity of hypoalbuminemia may be associated with poorer outcomes in the 30 days following hip fracture surgery. The researchers reviewed data on 12,373 patients from the National Surgery Quality Improvement Project. They found that 6,506 patients (52.6 percent) had normal albumin levels (albumin ≥ 3.5 g/dL), 3,205 (25.9 percent) patients were mildly malnourished (albumin 3.1–3.49 g/dL), 2,265 patients (18.3 percent) were moderately malnourished (albumin 2.4–3.1 g/dL), and 397 patients (3.2 percent) were severely malnourished (albumin < 2.4 g/dL). The researchers found that severe malnutrition was associated with a two-fold increase in the odds of postoperative complications and mortality compared with mild malnutrition and that increasing severity of malnutrition was associated with significantly longer lengths of stay and higher likelihood of related readmission.

Patient safety
Multimodal analgesia—
Findings published in Anesthesiology (online) suggest that, compared to opioids alone, a multimodal analgesia regimen may help reduce opioid prescribing and complications for joint arthroplasty patients. The researchers reviewed data on 512,393 THAs and 1,028,069 total knee arthroplasties (TKAs) and found that 85.6 percent of patients (n = 1,318,165) received multimodal analgesia. Compared to patients who received opioids-only, they found that patients who received multimodal analgesia experienced 19 percent fewer respiratory complications and 26 percent fewer gastrointestinal complications. They also found that there was up to 18.5 percent decrease in opioid prescriptions and a 12.1 percent decrease in length of stay. The researchers state that TKA analyses displayed similar patterns. They write that NSAIDs and cyclooxygenase-2 inhibitors appeared to be the most effective modalities used, but further study will be required to determine an optimized multimodal regimen.

DVT risk—According to a study conducted in Taiwan and published in JAMA (Feb. 27), varicose veins may be associated with a significantly increased risk of incident DVT. Members of the research team conducted a retrospective, cohort study of 212,984 patients with varicose veins and 212,984 matched controls. Over 7.3-year to 7.8-year follow-up, they found that patients diagnosed with varicose veins were at increased risk for DVT, pulmonary embolism (PE), and peripheral artery disease (PAD) compared to controls. However, they state that the findings for PE and PAD are less clear due to the potential for confounding. “Whether the association between varicose veins and DVT is causal or represents a common set of risk factors requires further research,” the researchers write.

Surgical antiseptics—Certain surgical antiseptics may yield potentially toxic byproducts when mixed, according to study data presented at the AAOS 2018 Annual Meeting. The investigators mixed all combinations of four antiseptic solutions commonly used in total joint arthroplasty: 4 percent chlorhexidine gluconate (CHX), Dakin’s solution (0.5 percent sodium hypochlorite, or NaOCl), povidone-iodine (BTD), and hydrogen peroxide (H2O2). They found that combinations of CHX and NaOCl, CHX and H2O2, and CHX and BTD reacted instantly and formed a precipitate, while NaOCl and H2O2 reacted to produce a gas. NaOCl and BTD did not react initially, but when additional NaOCl was added, a reaction (color change) was observed. At least two of the reactions tested—CHX + NaOCl and NaOCl + H2O2—yielded byproducts that could be toxic to human beings. Only H2O2 and BTD did not react in a visible manner.

Triamcinolone injection—A study in Clinical Orthopaedics and Related Research (online) suggests that triamcinolone injection of the knee may be linked to an increase in intraocular pressure. The authors conducted a prospective, cohort study of 62 patients with primary OA of the knee, of whom 31 (50 percent) were treated with triamcinolone and 31 (50 percent) were treated with hyaluronic acid. At one-week follow-up, they found that mean intraocular pressure increased by 2.79 mm Hg in the triamcinolone cohort, but did not change among patients in the hyaluronic acid cohort. Overall, nine of 29 patients in the triamcinolone cohort displayed a ≥ 7 mm Hg intraocular pressure elevation at one week, and of those, four of five triamcinolone patients available at one-month follow-up remained elevated > 7 mm Hg from baseline. “Further larger scale randomized investigations are warranted to determine the longevity of this pressure elevation as well as long-term clinical implications, including optic nerve damage and visual field loss,” the authors write.