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AAOS Now

Published 10/1/2016

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)

Hip and knee
ACL reconstruction—A study in The American Journal of Sports Medicine (AJSM; online) compares long-term outcomes for patients who undergo isolated endoscopic anterior cruciate ligament (ACL) reconstruction using either hamstring (HT) or patellar tendon (PT) autograft. The authors conducted a cohort study of 180 patients who underwent isolated ACL reconstruction. At 20-year follow-up, they found that 16 patients (18 percent) in the HT cohort and 9 patients (10 percent) in the PT cohort had experienced ACL graft rupture. However, they also noted improved International Knee Documentation Committee scores, reduced kneeling pain, and less radiographic osteoarthritic change in the HT cohort compared to the PT cohort. Increased likelihood of ACL graft rupture was associated with male sex, non-ideal tunnel position, and age younger than 18 years at the time of surgery.

Return to sport—Data published in AJSM (online) finds no significant difference in return-to-sport rates between primary and revision ACL reconstruction. The authors conducted a single-center, prospective, cohort study of 552 patients who underwent either primary (n = 497) or revision (n = 55) ACL reconstruction. At 1-year follow-up, they found no significant difference in return-to-sport rate across cohorts. However, patients in the primary reconstruction group resumed their usual sport significantly more often compared to those in the revision group. In addition, at 1 year, functional scores were significantly better in the primary reconstruction group for subjective International Knee Documentation Committee score; Knee injury and Osteoarthritis Outcome Score Symptoms/Stiffness, Activities of Daily Living, Sport, and Quality of Life subscales; and ACL–Return to Sports after Injury scores. Overall, there were eight retears during a new sport-related injury within a mean 8.9 months: seven (1.4 percent) in the primary reconstruction group and one (1.8 percent) in the revision reconstruction group.

Minority patients—Findings published in The Journal of Bone & Joint Surgery (JBJS; Aug. 3) suggest that minority patients may be less likely to undergo total knee arthroplasty (TKA), but are more likely to experience adverse outcomes. The research team reviewed 8 years of data across eight racially diverse states and found that, in comparison with whites, black, Hispanic, Asian, Native American, and mixed-race populations had significantly lower rates of TKA utilization. Overall, patients from minority groups were less likely to undergo TKA in high-volume hospitals. In addition, mortality rates were significantly higher for blacks, Native Americans, and mixed-race patients, and blacks and mixed-race patients saw increased complication rates compared to white patients.

Intertrochanteric fracture—According to a study in the Journal of Orthopaedic Trauma (August), subfascial administration of tranexamic acid (TXA) around the fracture site may be associated with a significant reduction in blood loss in older patients who undergo intramedullary (IM) nailing for intertrochanteric fractures. The researchers conducted a prospective, randomized trial of 200 patients older than 65 years who had an intertrochanteric fracture treated by IM nail. They found that subfascial administration of 3g of TXA around the fracture site at the end of the surgical procedure was linked to a 43 percent reduction in transfusion requirements compared to the control cohort, which did not receive TXA. The researchers found no difference between cohorts in terms of late complications and overall mortality rate.

Gabapentinoids—Findings from a study in JBJS (Aug. 17) suggest little evidence to support the routine use of gabapentinoids in the management of acute pain following TKA. The researchers conducted a meta-analysis of 12 randomized, controlled trials of patients who underwent elective primary TKA, and which compared the use of the gabapentinoid class of drugs or pregabalin against placebo. They found no difference in pain scores across cohorts at 12, 24, 48, or 72 hours following surgery. The researchers note that use of pregabalin was associated with reduced pain scores at 24 and 48 hours following surgery, although the difference was minor and determined to be not clinically important. Similarly, gabapentinoids were associated with a small, but not clinically important, reduction in cumulative opioid consumption at 48 hours postoperative. The researchers state that there was no difference in knee flexion at 48 hours following surgery or in incidence of chronic pain at 3 months or 6 months after surgery associated with the use of gabapentinoids. In addition, they state that gabapentinoids were associated with a significant reduction in the incidence of nausea, but pregabalin was also associated with a clinically relevant increase in the risk of sedation.

Cartilage and osteochondral lesions—A study in JBJS (Aug. 17) compares autologous chondrocyte implantation (ACI) with microfracture for the treatment of cartilage and osteochondral lesions in the knee. The authors report on long-term follow-up of a randomized trial of 80 patients who had a single symptomatic chronic cartilage defect on the femoral condyle without general osteoarthritis (OA). At 15-year follow-up, no significant difference across treatment cohorts were found in International Cartilage Repair Society, Lysholm, Short Form-36, and Tegner forms. However, the authors noted 17 failures and 6 TKAs in the ACI group, compared to 13 failures and 3 TKAs in the microfracture group. In addition, 57 percent of surviving patients in the ACI group and 48 percent of surviving patients in the microfracture group had radiographic evidence of early OA, although the difference was not determined to be significant.

Shoulder and elbow
Rotator cuff tear—A study in the Journal of Shoulder and Elbow Surgery (JSES; online) examines trends in surgical and nonsurgical treatment of rotator cuff tears among Medicare patients. The researchers reviewed data on 878,049 patients diagnosed with rotator cuff tear, 397,116 of whom underwent rotator cuff repair. From 2005 through 2012, the percentage of patients treated initially with physical therapy fell from 30.0 percent to 13.2 percent, and the percentage who received subacromial/glenohumeral injections decreased from 6.00 percent to 4.19 percent. Over the same period, the percentage of patients who underwent rotator cuff repair increased from 33.8 percent to 40.4 percent from 2005 to 2012. The researchers note that overall, Charlson Comorbidity Indexes were significantly lower in surgically treated patients compared with each nonsurgical treatment examined.

Shoulder arthroplasty—Findings from a study in Clinical Orthopaedics and Related Research (online) suggest six preoperative patient factors that may be associated with improved outcomes following shoulder arthroplasty. The authors conducted a prospective study of 294 patients who underwent hemiarthroplasty, arthroplasty for cuff tear arthropathy, ream and run arthroplasty, total shoulder, or reverse total shoulder arthroplasty. At 2-year follow-up, they found that the following factors were significantly associated with better outcomes: American Society of Anesthesiologists Class I, shoulder problem not related to work, lower baseline Simple Shoulder Test score, no prior shoulder surgery, humeral head not superiorly displaced on the anteroposterior radiograph, and glenoid type other than A1. The authors note that neither preoperative glenoid version nor posterior decentering of the humeral head on the glenoid were associated with the outcomes.

Radiography—Data published in the JSES (August) suggest that postdiagnosis radiographs may not alter treatment of radial head fractures that do not have any associated ligament injuries or fractures. The researchers identified 415 adult patients with nonsurgical treatment for isolated Broberg and Morrey modified Mason type 1 or 2 fractures at a single center. Of 255 patients (262 fractures) with subsequent radiographs, they found that just one patient (0.4 percent) was offered surgery but declined. Based on multivariable analysis, the researchers note that surgeon-to-surgeon variation was the most influential factor in likelihood of subsequent radiography.

Spine
Spine OA—According to a study conducted in Canada and published in the Journal of Clinical Investigation Insight (online), two biomarkers may be linked to increased likelihood of spine osteoarthritis (OA). The researchers identified a cohort of 55 patients being treated with compression or diskectomy for facet joint (FJ) cartilage degeneration. From those, they screened 2,100 microRNAs and identified two (miR-181a-5p and miR-4454) that were significantly elevated in FJ OA cartilage compared with control facet cartilage.

Scoliosis—A study in JBJS (Aug. 3) examines the influence of the Risser sign on the need for surgery in children wearing orthoses for the treatment of adolescent idiopathic scoliosis (AIS). The research team conducted a prospective study of 168 pediatric patients with a curve magnitude between 25° and 45°; a Risser stage of 0, 1, or 2; and who had been prescribed bracing. All patients were followed until the cessation of bracing or the need for surgery. The research team found that prevalence of surgery or progression to a curve magnitude of ≥ 50° was 44.2 percent for patients at Risser stage 0 (n = 120), 6.9 percent for patients at Risser stage 1 (n = 29), and 0 percent for patients at Risser stage 2 (n = 19). They note that patients at Risser stage 0 are at risk for surgery, even if they wear a brace for 12.9 hours per day—the number of hours linked with a successful outcome in the Bracing in Adolescent Idiopathic Scoliosis Trial. In addition, patients with open triradiate cartilage were at highest risk, especially those with curves of ≥ 30°. The research team writes that "Risser stage-0 patients should be prescribed a minimum of 18 hours of brace wear," and that "bracing should be initiated for curves of < 30° in patients at Risser stage 0, especially those with open triradiate cartilage."

Vertebroplasty—Findings from a study conducted in Australia and published in The Lancet (online) suggest that vertebroplasty may be an appropriate intervention for patients with acute osteoporotic spinal fractures of less than 6 weeks duration. The authors conducted a multicenter, randomized, double-blind, placebo-controlled trial of 120 patients with one or two osteoporotic  vertebral fractures of less than 6 weeks duration and Numeric Rated Scale (NRS) back pain greater than or equal to 7 out of 10, 61 of whom were treated with vertebroplasty and 59 with placebo. At 14-day follow-up, they found that 44 percent (n = 24) of patients in the vertebroplasty group and 21 percent (n = 12) of patients in the control group had an NRS pain score below 4 out of 10. Overall, there were two serious adverse events in each cohort, and three patients in each cohort died from causes judged unrelated to the procedure.
Patient safety

Bariatric surgery—According to a study conducted in Canada and published in The BMJ (online), patients who undergo bariatric surgery may be more likely to experience fractures than obese or nonobese patients. The researchers conducted a retrospective, nested, case-control study of 12,676 patients who underwent bariatric surgery, and 38,028 obese and 126,760 nonobese age- and sex-matched controls. They found that, prior to surgery, patients undergoing bariatric surgery were more likely to fracture than obese or nonobese controls. This remained true at mean 4.4-year follow-up. The researchers note that prior to surgery, the risk of distal lower limb fracture was higher, upper limb fracture risk was lower, and risk of clinical spine, hip, femur, or pelvic fractures was similar in the bariatric and obese groups compared with the nonobese group. Following surgery, risk of distal lower limb fracture decreased, while risk of upper limb, clinical spine, pelvic, hip, or femur fractures increased. The researchers state that the increase in risk of fracture reached significance only for biliopancreatic diversion.

Fragility fracture—A study in JAMA Internal Medicine (online) suggests that many patients continue to take medications linked with increased fracture risk following a fragility fracture. The authors conducted a retrospective cohort study of 168,133 patients with a fragility fracture. They found that most patients were exposed to at least one nonopiate drug associated with increased fracture risk during the 4 months prior to fracture (77.1 percent of hip, 74.1 percent of wrist, and 75.9 percent of shoulder fracture patients). About 7 percent of such patients discontinued this drug exposure after the fracture, but this was offset by new users after fracture, leaving the proportion of the cohort exposed following fracture effectively unchanged. In addition, the authors note that less than 25 percent of patients used drugs to strengthen bone density both before and after fracture.

Opioids—According to a study in the Journal of General Internal Medicine (online), opioid prescribing patterns during the initiation month may affect the likelihood of long-term opioid use. The authors conducted a retrospective, cohort study of 536,767 opioid-naïve patients who filled an opioid prescription, of whom 26,785 (5.0 percent) became long-term users. They found that higher numbers of fills and cumulative morphine milligram equivalents (MME) during the initiation month were associated with increased risk of long-term use. Among patients younger than 45 years who used short-acting opioids and who did not die in the follow-up year, the adjusted odds ratio (OR) for long-term use among those receiving two fills versus one was 2.25. In addition, compared to those who received less than 120 total MMEs, those who received between 400 and 799 total MMEs had an OR of 2.96 for long-term use. Finally, the authors note that patients who initially received long-acting opioids had a higher risk of long-term use than those who received short-acting drugs.

Zika virus—Findings published in The BMJ (online) suggest that Zika virus infection in a pregnant woman may increase the risk of arthrogryposis in the baby. The researchers conducted a retrospective case series study of seven children with arthrogryposis and a diagnosis of congenital infection presumably caused by Zika virus during the Brazilian microcephaly epidemic. They found that the brain images of all seven children were characteristic of congenital infection and arthrogryposis, and that two children tested positive for IgM to Zika virus in the cerebrospinal fluid. Five of the children underwent brain computed tomography (CT) and magnetic resonance imaging (MRI) and the remaining two CT only. The researchers found that all the infants had malformations of cortical development, calcifications predominantly in the cortex and subcortical white matter, reduction in brain volume, ventriculomegaly, and hypoplasia of the brainstem and cerebellum. In addition, in four children, MRI of the spine displayed apparent thinning of the cord and reduced ventral roots.

FRAX—A study in the Archives of Osteoporosis (online) examines intervention thresholds for the World Health Organization Fracture Risk Assessment Tool (FRAX). The researchers conducted a systematic review of 82 guidelines or academic papers that incorporated FRAX. Of those, 58 recommended a fixed intervention threshold, 22 recommended an age-dependent threshold, and 2 adopted both fixed and age-dependent thresholds. The researchers found that fixed probability thresholds ranged from 4 percent to 20 percent for a major fracture and from 1.3 percent to 5 percent for hip fracture. Overall, 39 of 58 publications used a threshold probability of 20 percent for a major osteoporotic fracture, and many also mentioned a hip fracture probability of 3 percent as an alternative intervention threshold. The researchers state that, across various countries, fixed probability thresholds were determined to match the prevalence of osteoporosis or to align with preexisting guidelines or reimbursement criteria. The researchers note that FRAX appears to be more effective overall than bone mineral density (BMD) for identifying individuals at high risk of osteoporosis; however, setting of intervention thresholds needs to be country-specific.

Fluoroquinolones—The U.S. Food and Drug Administration (FDA) has approved changes to the warning labels of fluoroquinolone antibacterial drugs intended for systemic use. The agency has determined that "fluoroquinolones should be reserved for use in patients who have no other treatment options for acute bacterial sinusitis, acute exacerbation of chronic bronchitis, and uncomplicated urinary tract infections because the risk of these serious side effects generally outweighs the benefits in these patients." Fluoroquinolone labels already contain a Boxed Warning for tendinitis, tendon rupture, and worsening of myasthenia gravis, as well as warnings regarding risks of peripheral neuropathy and central nervous system effects, and cardiac, dermatologic, and hypersensitivity reactions.