AAOS Now

Published 7/1/2016

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)

Patient safety
Compartment syndrome—According to a study published in the Journal of Orthopaedic Trauma (JOT; online), use of an algorithm based on preoperative diastolic blood pressure (DBP) may help avoid release of posterior compartments in patients with lower leg compartment syndrome (CS). The authors conducted a prospective cohort study of 37 patients who were managed by one surgeon at a single center. After a standard anterior and lateral compartment release via a full-length lateral incision was performed, the superficial and deep posterior compartments were measured with the heel resting on a bolster. A [DELTA]P <30 mm hg from preoperative dbp was considered to be a positive finding warranting a separate medial incision for release of the posterior compartments. after full-length release of the anterior and lateral compartments, only 3 of 37 patients (8 percent) required posterior release based on the algorithm. the authors state that sequelae of a missed posterior compartment syndrome did not develop in patients who had only an anterolateral release.>

Resistant bacteria—Antimicrobial Agents and Chemotherapy reports that a strain of Escherichia coli that is resistant to all known antibiotics has been discovered in a patient in the United States. The E coli strain contains the mcr-1 gene, which confers resistance to colistin—considered by some experts to be an antibiotic of last resort.

Antibiotic stewardship—A study published in Clinical Infectious Diseases (online) reviewed data on 4,184 U.S. hospitals from the 2014 National Healthcare Safety Network Annual Hospital Survey and found that only 39 percent reported having an antibiotic stewardship program that met all seven core elements of the U.S. Centers for Disease Control and Prevention Core Elements for Hospital Antibiotic Stewardship Programs.

Septic arthritis—A study published in The Journal of Bone & Joint Surgery (JBJS; May 4) attempts to identify predictors of septic arthritis in pediatric patients. The researchers retrospectively reviewed records of 189 patients younger than age 18 years with knee effusions who underwent arthrocentesis at a single institution. Overall, 23 patients had culture-positive septic arthritis, 26 patients had culture-negative septic arthritis, and 140 patients had Lyme disease. They found that, although septic arthritis of the knee and Lyme monoarthritis may be difficult to distinguish clinically, the presence of pain with short arc motion, C-reactive protein of >4.0 mg/L, patient-reported history of fever, and age younger than 2 years were independent predictors of septic arthritis in pediatric patients. In addition, they found that an increasing number of factors present in the patient was associated with an increased risk of septic arthritis.

Preoperative preparation—According to a study published in Foot & Ankle International (May) preoperative preparation with isopropyl alcohol solution followed by chlorhexidine solution may reduce bacterial colonization compared to the reverse, although both application methods may be effective. The research team conducted a prospective, randomized trial of 95 consecutive patients undergoing orthopaedic foot and ankle surgery who received either 4 percent chlorhexidine application followed by alcohol rinse (n = 49) or alcohol followed by chlorhexidine (n = 46). Both groups had 100 percent bacterial growth from specimens obtained prior to surgical site preparation. The researchers found that culture results favored the alcohol-first group at all collection points: after draping, after completion of surgery, and after skin closure. There was one surgical site infection in the first 30 days in each cohort. There were no additional skin or wound complications during the 6-month study follow-up.

Showering—Findings from a small study published in The Journal of Arthroplasty (online) suggest there may be little advantage to delayed showering after primary total knee arthroplasty (TKA). The authors conducted a randomized, controlled trial of 32 TKA patients, 16 of whom were allowed to shower at 2 days postoperative and 16 of whom were asked to wait until 2 weeks postoperative before showering. They found no difference between cohorts in rate of colonization or bacterial type at any time point (preoperative, just after incision closure, dressing removal, and 2 weeks postoperative). In addition, infection did not develop in any patients in either group.

Antibacterial drugs—The U.S. Food and Drug Administration (FDA) advises that the serious side effects associated with fluoroquinolone antibacterial drugs generally outweigh the benefits for patients with sinusitis, bronchitis, and uncomplicated urinary tract infections who have other treatment options. An agency safety review has shown that, when used systematically, fluoroquinolones are associated with disabling and potentially permanent serious side effects that can occur together. Side effects can involve the tendons, muscles, joints, nerves, and central nervous system. As a result, FDA is requiring the drug labels and medication guides for all fluoroquinolone antibacterial drugs to be updated to reflect this new safety information. The agency states that healthcare professionals should stop systemic fluoroquinolone treatment immediately if a patient reports serious side effects and switch to a nonfluoroquinolone antibacterial drug to complete the patient's treatment course.

Hip
Computer navigation—Data from a study published online in the journal Clinical Orthopaedics and Related Research suggest that computer-assisted surgery (CAS) used for cup placement may not confer any substantial advantage in function, wear rate, or survivorship following total hip arthroplasty (THA). The authors conducted a randomized controlled study of 60 patients who underwent THA using CAS (n = 30) or conventional technique (n = 30) for cup placement. At 10-year follow-up, of 28 available patients in the CAS cohort and 27 in the conventional cohort, the authors found no significant difference between groups as assessed by Harris Hip Score, mean acetabular wear, or survivorship free from aseptic loosening.
Complications—Findings from a study published online in The Journal of Arthroplasty (online) suggest that malnutrition may increase with obesity and, compared with obesity, may be an improved predictor of complications following THA. The authors reviewed data on 20,210 THA patients for whom preoperative albumin measurements were available. They found that malnutrition (albumin <3.5 g dl) incidence increased from 2.8 percent in obese i patients (body mass index [bmi] 30 to 34.9) to 5.7 percent in obese iii patients (bmi ≥40). the authors noted that malnutrition was a more robust predictor than any obesity class for any postoperative complication, major complication, respiratory complication, blood transfusion, and extended length of stay.>

IF fixation—Findings from a study published in JOT (online) suggest similar 5-year outcomes for two devices designed for fixation of intertrochanteric fracture (IF). The researchers conducted a prospective, randomized study of 104 patients with mean age of 81.2 years, who were treated for IF using either an integrated two-screw cephalomedullary nail or a single-screw device. Based on 33 patients available at 5-year follow-up, they found that neither group had significant implant-related complications or differences in terms of functional outcome. However, patients in the two-screw cohort had shorter hospital stays and were more likely to have returned to prefracture status at 6 months.

Osteoporosis—Research presented at the annual scientific meeting of the American Geriatrics Society suggests that more than 70 percent of older hip fracture patients may not be informed of the potential for osteoporosis, despite that condition's association with hip fracture. The research team conducted a telephone survey of 42 hip fracture patients aged 75 years or older and found that 57 percent reported that their hospital physicians had not suggested osteoporosis medication following hip fracture, and 25 percent said they would reject taking such prescribed drugs. Overall, 36 percent of respondents said they hadn't received a prescription for osteoporosis medication. For many of the remainder, treatment consisted simply of calcium and vitamin D.

Acetabular labral tears—Data from a study published in The American Journal of Sports Medicine (online) suggest that, for appropriate patients, hip arthroscopy may be more cost-effective and associated with improved outcomes compared to structured rehabilitation alone for patients with acetabular labral tears. The authors used a Markov decision model and cost estimates from national averages of Medicare reimbursements for a cohort representative of patients undergoing hip arthroscopic surgery at a single center. Compared to rehabilitation alone, they estimated that arthroscopy cost an additional $2,653 in 2014 dollars, but was associated with an additional 3.94 quality-adjusted life-years (QALYs) over a patient's lifetime. Overall, arthroscopic surgery was cost-effective for 94.5 percent of patients. In addition, although arthroscopic surgery decreased in cost-effectiveness with increasing age, it remained more cost-effective than rehabilitation for patients in the second to seventh decades of life. The lifetime incidence of symptomatic hip osteoarthritis was more than twice as high for patients treated with rehabilitation compared with arthroscopic surgery.

FAI—A study published in JBJS (May 18) examines age and sex factors that may affect outcomes of hip arthroscopy for femoroacetabular impingement (FAI). The authors conducted a prospective study of 150 patients who were treated with hip arthroscopy for FAI by a single surgeon. At minimum 2-year follow-up, they found that across six patient categories based on sex and age, all groups demonstrated significant improvements in the Hip Outcome Score Activities of Daily Living Subscale, Hip Outcome Score Sport-Specific Subscale, and modified Harris hip score. However, patients older than age 45 years scored significantly worse on all outcomes compared with patients younger than age 30 years and patients age 30 to 45 years. Overall, female patients older than age 45 years demonstrated the lowest outcome scores. In the age group of 45 years or younger, female patients performed as well as male patients in terms of hip clinical outcome scores.

Knee
ACL reconstruction—A study published in The American Journal of Sports Medicine (AJSM; online) examines predictors of clinical outcome after revision anterior cruciate ligament (ACL) reconstruction. The research team conducted a cohort study of 1,205 patients who underwent revision ACL reconstruction by 83 surgeons at 52 hospitals. Of 989 patients surveyed at 2-year follow-up, they found that previous meniscal injury and current articular cartilage damage were associated with the poorest outcomes in terms of decreased sports participation, more pain, more stiffness, and more functional limitation. The research team states that prior lateral meniscectomy and current grade 3 to 4 trochlear articular cartilage changes were linked to the worst outcome scores.

TXA—Data from a study published in JBJS (May 18) suggest that combined administration of intravenous (IV) and intra-articular (IA) tranexamic acid (TXA) may be associated with reduced blood loss compared to IV TXA alone for patients who undergo TKA. The authors conducted a randomized, double-blind, placebo-controlled trial of 60 TKA patients treated with either combined administration of TXA consisting of 1 g administered intravenously preoperatively and 3 g diluted in 100 mL of saline solution administered intra-articularly after closure of the capsule, or 1 g of TXA administered intravenously only and 100 mL of saline solution administered intra-articularly. They found that the mean 24-hour blood loss was 466 mL in the TXA IV and IA group and 743 mL in the TXA IV and placebo group. In addition, second-day blood loss was 644 mL in the TXA IV and IA cohort and 1,017 mL in the TXA IV and placebo cohort.

ACL autograft—A study published in AJSM (online) finds minor differences in long-term outcomes for patients who undergo ACL reconstruction using a patellar tendon (PT) autograft compared to a hamstring tendon (HT) autograft. The research team conducted a randomized, controlled trial of 147 patients who underwent unilateral primary ACL reconstruction using either a PT autograft (n = 61) or an HT autograft (n = 86). At mean follow-up of 202.6 months for the PT group and 191.9 months for the HT group, they found no significant differences across cohorts according to the manual Lachman test, KT-1000 arthrometer manual maximum test, radiographic osteoarthritis, patient-reported outcomes, or range of motion. However, the research team notes that knee laxity measurements revealed significantly more patients with a normal pivot-shift test finding in the HT group compared with the PT group and that patients in the PT group had significantly more difficulty knee walking.

Shoulder and elbow
UCL reconstruction—According to data published in AJSM (online), six key performance factors may present significant risk factors for ulnar collateral ligament (UCL) reconstruction among Major League Baseball (MLB) pitchers. The authors conducted a case control study of 104 MLB pitchers who underwent UCL reconstruction surgery and 104 age- and position-matched control participants. They found that fewer days between consecutive games, smaller repertoire of pitches, less-pronounced horizontal release location, smaller stature, greater mean pitch speed, and greater mean pitch counts per game were all significant predictors of UCL reconstruction.

Spine
Provocative diskography—Findings from a study published in The Spine Journal suggest that disk puncture and pressurized injection performed during provocative diskography may be linked to increased risk of clinical disk problems. The researchers conducted a prospective, matched cohort study of 75 patients without current low back pain who underwent provocative diskography at the L3–S1 disks, and 75 matched controls who underwent a similar evaluation except for diskography injections. At 10-year follow-up, 57 diskography participants and 53 control participants had completed all interval surveillance evaluations. The researchers found that there were 16 lumbar surgeries in the diskography group and four in the control group. In addition, medical visits, computed tomography and magnetic resonance imaging examinations, work loss, and prolonged back pain episodes were all more frequent in the diskography group compared with controls.

Acute LBP—Data published in JAMA Internal Medicine (online) suggest a lack of evidence regarding the efficacy of opioid analgesics for relief of acute low back pain (LBP). The researchers conducted a meta-analysis of 20 randomized, placebo-controlled trials covering 7,925 patients. Overall, 13 trials covering 3,419 participants evaluated short-term effects on chronic LBP, while no placebo-controlled trials enrolled patients with acute LBP. In half of the 13 trials, at least 50 percent of participants withdrew due to adverse events or lack of efficacy. The researchers noted moderate-quality evidence that opioid analgesics reduce pain in the short-term, but clinically important pain relief was not observed within the dose ranges evaluated (40.0- to 240.0-mg morphine equivalents per day).
Hand and wrist
Revision scaphoid nonunion surgery—Data from a small study published in The Journal of Hand Surgery (May) examines complications associated with the use of recombinant human bone morphogenetic protein (rhBMP-2) in revision scaphoid nonunion surgery. The research team retrospectively reviewed six cases of scaphoid nonunion revision surgery comprising open reduction and internal fixation (ORIF). All patients were treated with revision screw fixation, bone graft, and rhBMP-2, with union determined by computed tomography. The research team found that notable heterotopic ossification developed in four patients, one of which required revision surgery. In addition, one patient had a loss of functional motion following revision surgery. Only one of the 6 patients healed without complications. "In this case series, the use of rhBMP-2 in scaphoid nonunions was associated with a higher complication rate than reported in previous studies," the research team writes. "Surgeons performing off-label use of rhBMP-2 should be aware of the potential for complications including heterotopic ossification."

Concussion
Recovery time—A study published in the Journal of Athletic Training (April) suggests that athletes who delay treatment for concussion may risk increased recovery time. The authors conducted a cross-sectional study of 97 college athletes with concussion, 50 of whom were not immediately removed from activity. They found that athletes with concussion who continued to play missed an average of 4.9 more days of playing time compared to those who were immediately removed. In addition, athletes who continued playing were approximately 2.2 times more likely to experience a prolonged recovery (8 or more days) compared with those who were immediately removed.

Concussion rates—According to a study published in JAMA Pediatrics (online), estimates of pediatric concussion incidence based solely on emergency department (ED) visits may underestimate the true incidence of injury. The authors reviewed data on 8,083 patients aged 17 years or younger who had one or more in-person clinical visits for concussion at a single center. They found that 81.9 percent (n = 6,624) presented at primary care, 5.2 percent (n = 418) within specialty care, and 11.7 percent (n = 947) within the ED. Overall, healthcare entry varied by age, with 52 percent of children aged 0 to 4 years entering via the ED, and more than three-quarters of patients aged 5 to 17 years entering via primary care. In addition, Medicaid patients were more likely than private payer and self-pay patients to use the ED for concussion care.