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AAOS Now

Published 6/1/2018

Second Look - Clinical News and Views

Patient safety

BMI criteria—A study in The Journal of Bone & Joint Surgery (JBJS; Apr. 4) attempts to assess various body mass index (BMI) criteria for total joint arthroplasty (TJA). The authors conducted a retrospective, cohort study of 27,671 TJAs to determine if various BMI eligibility criteria had been enforced, how many short-term complications would have been avoided, how many complication-free surgical procedures would have been denied, and the positive predictive value of BMI eligibility criteria as tests for major complications.

They found that with a BMI criterion of ≥ 40 kg/m2, 1,148 patients would have been denied a surgical procedure free of major complications, and 83 patients would have avoided a major complication. They write that the positive predictive value of a complication based on a BMI of ≥ 40 kg/m2 as a test for major complications was 6.74 percent, while the positive predictive value of a complication using a BMI criterion of ≥ 30 kg/m2 was 5.33 percent. “Although the acceptable balance between avoiding complications and providing access to care can be debated,” they write, “such a quantitative assessment helps to inform decisions regarding the advisability of enforcing a BMI criterion for [TJA].”

Synthetic cannabinoids—The U.S. Centers for Disease Control and Prevention (CDC) has issued an alert regarding potential life-threatening vitamin K-dependent antagonist coagulopathy associated with the use of synthetic cannabinoids. The agency states that, since Mar. 8, 2018, at least 160 people have presented to healthcare facilities with serious unexplained bleeding, with the preponderant number of presentations in Illinois, with other cases reported in Florida, Indiana, Kentucky, Maryland, Missouri, Pennsylvania, Virginia, and Wisconsin. CDC recommends that providers, including orthopaedic and trauma specialists, “should be aware that patients with a history of synthetic cannabinoids (e.g., K2, Spice, and AK47) use may be anti-coagulated without clinical signs of coagulopathy. These patients should be screened for vitamin K-dependent anti-coagulant coagulopathy prior to their procedure.”

Benzodiazepines and opioids—Findings published in JAMA Psychiatry (online) suggest that patients who are prescribed benzodiazepines may be more likely than the general population to also be prescribed opioids, despite an increased risk of overdose.

The researchers reviewed data on 13,146 patient visits from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey from Jan. 1, 2005, through Dec. 31, 2015. They found that rates of new opioid prescriptions among adults using a benzodiazepine increased from 189 to 351 per 1,000 persons between 2005 and 2010, then decreased to 172 per 1,000 persons by 2015. Over the same period, new opioid prescriptions in the general population not using benzodiazepines increased nonsignificantly from 78 to 93 per 1,000 persons from 2005 to 2010 and decreased nonsignificantly to 79 per 1,000 persons by 2015.

After adjustment for demographic characteristics, comorbidities, and diagnoses associated with pain, the researchers found that, compared with the general population, the likelihood of receiving a new opioid prescription during an ambulatory visit remained higher for patients concurrently using benzodiazepines.

Supracondylar humeral fracture—A study in the Journal of Pediatric Orthopaedics (April) suggests that a removable long-arm soft cast may be appropriate for children with nondisplaced supracondylar humeral fracture. Members of the research team conducted a randomized, controlled trial of 100 consecutive pediatric patients who presented with a closed, nondisplaced, type I supracondylar humeral fracture or an occult, closed, acute elbow injury. Among the 100 patients, 50 were treated with a long-arm, traditional (hard) fiberglass cast and 50 were treated with a long-arm, soft fiberglass cast. At latest follow-up, patients in both groups displayed similar mean arc of motion and had achieved similar relative arc of motion to that of the contralateral side. The researchers write that pain scores were low and comparable across cohorts over the study period, and all patients in both groups reported the highest rate of satisfaction at eight-week follow-up.

Fracture and fall prevention recommendations—The U.S. Preventive Services Task Force (USPSTF) has released two final recommendation statements and evidence summaries on the prevention of fractures and falls in older adults. Among other things, the task force states that:

Lower doses of vitamin D and calcium do not prevent fractures. USPSTF recommends against daily supplementation at lower doses in women who have gone through menopause.

Evidence is unclear about whether higher doses of vitamin D and calcium may help prevent fractures in women who have gone through menopause.

There is not enough evidence to recommend for or against vitamin D and calcium supplementation, alone or combined, to prevent fractures in men or in women who have not gone through menopause.

Regarding fall prevention, USPSTF recommends exercise or physical therapy (PT) for adults aged 65 years and older who live at home and are at increased risk of falls, and states that based on an individual’s circumstances, clinicians should selectively check older adults’ risks for falls and offer tailored interventions that address those specific risks.

Trauma

Distal radial fracture malunion—A study published in JBJS (April 18) examines the long-term effects of distal radial fracture malunion. The authors conducted a prospective, cohort study of 63 adult patients with distal radial fracture who were treated with casting or percutaneous fixation. At 12- to 14-year follow-up, they found that 25 patients had malunion, 38 patients had osteoarthritis (OA), and nine patients had styloid nonunion. Compared to patients without malunion, the authors found that those with malunion had significantly worse Disabilities of the Arm, Shoulder and Hand (DASH) scores, and visual analog scale (VAS) pain and satisfaction scores.

They found no significant difference across cohorts in range of motion or grip strength, and no significant association for OA and styloid nonunion with DASH scores, VAS pain or satisfaction scores, or grip strength.

Home therapy—Findings in JBJS (Apr. 18) suggest home exercise may offer benefits over formal PT for patients with a nondisplaced or minimally displaced fracture of the radial head or neck. Members of the research team conducted a prospective, randomized trial of 51 patients treated with either a home-exercise program (n = 25) or formal, outpatient PT (n = 26). At six-week follow-up, they found that patients in the home-exercise cohort had significantly improved DASH scores compared to those in the PT cohort. At three-month, six-month, and average 16.6-month final follow-ups, they found no significant differences across cohorts for any DASH outcome measure (pain, time to clinical healing, and range of motion).

Spine

Chronic neck pain—Data in the journal Spine (online) suggest that transcutaneous electrical nerve stimulation (TENS) and interferential current (IFC) therapies may be effective for the treatment of chronic neck pain but confer no additional benefit over neck stabilization exercise (NSE) alone. The researchers conducted a prospective, randomized, single-blind study of 81 patients with chronic neck pain, who were randomly assigned to receive NSE, TENS + NSE, or IFC + NSE. All patients received 15 sessions of PT, with group exercise accompanied by a physiotherapist for three weeks and an additional three weeks of home exercise.

An intra-group assessment found that the study achieved its purpose of pain reduction, increase in range of motion,
reduction in drug use, and improvement of disability, quality of life, and mood in all three treatment groups. However, at six- and 12-week follow-up, the researchers noted no difference in clinical outcomes across cohorts.

Hip and knee

PJI of the hip—Findings published in the European Journal of Epidemiology (online) suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating periprosthetic joint infection (PJI) of the hip. The researchers conducted a meta-analysis of 1,856 patients with PJI of the hip from 44 cohorts across four continents. They identified 222 reinfections at median 3.7-year follow-up.

The researchers found that one-stage revision was associated with a reinfection rate of 16.8 per 1,000 person-years of follow-up, while two-stage revision was linked to 32.3 reinfections per 1,000 person-years of follow-up. Compared with one-stage revision, the age- and sex-adjusted hazard ratio of reinfection for two-stage revision was 1.70.

Return to sport—A study published in The American Journal of Sports Medicine (online) examines predictors of return to knee-strenuous sports after anterior cruciate ligament (ACL) reconstruction. The researchers conducted a case-control study of 272 patients with a mean age of 25 years. In multivariable analysis at 12-month follow-up, they found that male sex, younger age at time of ACL reconstruction, higher preinjury score on the Tegner Activity Scale, and absence of injury to the meniscus and medial collateral ligament were associated with higher likelihood of return to sport. In addition, a univariable analysis suggested that absence of cartilage injury was also linked to an increased likelihood of return to sport.

Shoulder and elbow

Pseudoparalysis—A study published in The American Journal of Sports Medicine (online) seeks to identify risk factors for postoperative new-onset pseudoparalysis (PONP) after arthroscopic repair of large to massive rotator cuff tears. The authors conducted a case-control study of 430 consecutive arthroscopic rotator cuff repairs, stratified according to the occurrence of PONP. They found that the incidence of PONP was 6.0 percent (n = 26). Predictors of PONP included torn subscapularis, ≥ 30 mm retraction of the torn supraspinatus, age ≥ 65 years, and preoperative stiffness. The reversal rate of PONP was 65.4 percent (17 of 26), and the mean time to PONP reversal was 10 months. The authors write that the occurrence and reversal of PONP were not related to retear, and that fatty infiltration of the supraspinatus lower than Goutallier grade 3 was the sole predictor of reversal.

Chronic lateral epicondylitis—Data from a small study in The American Journal of Sports Medicine (April) suggest that surgical excision of the degenerative portion of the extensor carpi radialis brevis (ECRB) may offer little benefit to patients with chronic lateral epicondylitis.

The researchers conducted a randomized, double-blind, placebo-controlled trial of 26 patients treated with either surgical excision of the macroscopically degenerated portion of the ECRB (n = 13) or sham surgery consisting of skin incision and exposure of the ECRB alone (n = 13). At six-month and 2.5-year follow-up, they found similar improvement in both cohorts in patient-rated pain frequency and severity, elbow stiffness, difficulty with picking up objects, difficulty with twisting motions, and overall elbow rating. In addition, both procedures were associated with improved epicondyle tenderness, pronation-supination range, grip strength, and modified Orthopaedic Research Institute–Tennis Elbow Testing System at six months.

The researchers observed no significant difference across groups in any parameter at any stage. They write that a post hoc futility analysis showed, based on the magnitude of the differences between the groups, that more than 6,500 patients would be needed per cohort to demonstrate a significant difference in primary outcome—patient-rated frequency of elbow pain with activity—at 26 weeks.