Published 9/1/2017

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).

—According to a study conducted in Norway and published in Clinical Orthopaedics and Related Research (online), risk of postoperative complication may be comparable whether low-molecular-weight heparin (LMWH) prophylaxis is initiated prior to or following total hip arthroplasty (THA). The authors reviewed data on 25,163 patients undergoing THA who were included in the Norwegian Arthroplasty Register and the Norwegian National Patient Register. Overall, 9,977 patients (40 percent) received preoperative LMWH and 15,186 patients (60 percent) received postoperative LMWH. After adjustment for age, sex, operation time, year of surgery, and American Society of Anesthesiologists class, the authors found no major differences across cohorts in bleeding event, thromboembolic episodes, other postoperative clinical complications, 6-month mortality, or readmission rate. The authors note that the postoperative approach reduced costs, decreased risks related to neuraxial anesthesia, and facilitated same-day admissions.

SCIP guidelinesFindings published in The Journal of Arthroplasty (August) suggest that implementation of Surgical Care Improvement Project (SCIP) guidelines may be associated with a reduction in mortality and other complications for patients who undergo elective THA. The authors reviewed data on 345,875 THA procedures from the Nationwide Inpatient Sample. They found that by following the institution of SCIP guidelines, the overall mortality following cardiac complications decreased 41 percent. There were also significant decreases in fatal cardiac complications, postoperative hypotension, myocardial infarction, and cardiac arrest. The authors note that in the wake of evidence questioning their safety and efficacy, the SCIP guidelines were retired in 2015. However, they argue that "evidence supports continuation of perioperative beta-blockade in primary elective total adult hip and knee arthroplasty."

SCFE—Data from a study conducted in the United Kingdom (U.K.) and published in Archives of Disease in Childhood (online) suggest that socioeconomic deprivation and childhood obesity may be associated with increased risk of slipped capital femoral epiphysis (SCFE) among pediatric individuals. The authors conducted a historic, cohort study of all patients younger than 16 years of age who had a diagnosis of SCFE and whose electronic medical records between 1990 and 2013 were held by one of 650 primary care practices in the U.K.. They found that over the term of the study, SCFE incidence remained constant at 4.8 cases per 100,000 patients. The authors also found a strong association between SCFE and area-level socioeconomic deprivation and predisease obesity.

ObesityData presented in The Journal of Bone & Joint Surgery (JBJS; July 19) suggest that obese patients may see pain relief and improved function following THA or total knee arthroplasty (TKA). The authors reviewed data from a national sample of 2,040 THA patients and 2,964 TKA patients. They found that increased obesity classification was linked to lower Short Form-36 Physical Component Summary (PCS) score at baseline and 6-month follow-up and that severely and morbidly obese patients displayed less postoperative functional gain compared to the other body mass index (BMI) groups. However, a greater obesity level was associated with more pain at baseline but increased postoperative pain relief, and average postoperative pain scores did not differ significantly according to BMI status. In addition, postoperative gain in PCS score did not differ by BMI level. A greater obesity level was associated with worse pain at baseline but greater pain relief at 6 months, and average pain scores at 6 months were similar across the BMI levels. The authors argue that obesity should not in itself be a deterrent to undergoing total joint arthroplasty to relieve symptoms.

Double-bundle ACL repair
Findings published in The American Journal of Sports Medicine (AJSM; online) suggest that double-bundle anterior cruciate ligament (ACL) reconstruction may be associated with reduced likelihood of graft failure compared to single-bundle ACL reconstruction. The authors conducted a randomized, controlled trial of 90 patients treated with double-bundle ACL reconstruction with bioabsorbable screw fixation (n = 30), single-bundle ACL reconstruction with bioabsorbable screw fixation (n = 30), or single-bundle ACL reconstruction with metallic screw fixation (n = 30). Of 81 patients available at 10-year follow-up, they found that one patient in the double-bundle cohort, seven patients in the single-bundle/bioabsorbable cohort, and three patients in the single-bundle/metallic cohort had experienced graft failure and undergone revision. Among the remaining 70 unrevised patients, the authors found no significant difference across cohorts in pivot-shift test, KT-1000 arthrometer measurements, or International Knee Documentation Committee and Lysholm knee scores.

BPTB autograft—According to a study published in AJSM (online), patients who undergo ACL reconstruction using hamstring autograft may be at increased risk of infection compared to those who receive bone–patellar tendon–bone (BPTB) autograft. The researchers conducted a meta-analysis of 21 level 1 and level 2 studies. They found that patients who received BPTB autograft had a 77 percent lower incidence of infection compared to those in the hamstring cohort. In addition, the incidence of infection was 66 percent lower with BPTB autografts compared with all other graft types. The researchers found no significant difference in incidence of infection after ACL reconstruction with autografts compared to ACL reconstruction with allografts.

Arthroscopic partial meniscectomy—Data from a study in JBJS (July 5) suggest there may be no benefit to arthroscopic débridement of unstable chondral lesions encountered during arthroscopic partial meniscectomy (APM). The authors reviewed information on 190 participants in the Chondral Lesions and Meniscus Procedures randomized controlled trial, 98 of whom received débridement and 92 of whom did not. At 1-year follow-up, they found no significant difference across cohorts in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), visual analog scale pain score, Short Form-36 (SF-36) health survey, range of motion, quadriceps circumference, or effusion. However, compared with patients who underwent débridement, patients who did not receive débridement displayed improvement in KOOS quality-of-life and SF-36 physical functioning scores, increased quadriceps circumference at 8 to 12 days and at 6 months, improvement in WOMAC and KOOS pain scores at 6 weeks, and improvement in SF-36 physical functioning scores at 3 months.

Minimally stabilized TKA—Data from a study conducted in Australia and published in JBJS (July 5) suggest an increased risk of revision for patients who undergo posterior-stabilized TKA compared to those who receive a minimally stabilized TKA. The researchers drew data from the Australian Orthopaedic Association National Joint Replacement Registry for two cohorts of patients: those treated by high-volume surgeons who preferred a minimally stabilized approach, and those treated by high-volume surgeons who preferred a posterior-stabilized approach. At 13-year follow-up, they found a 5 percent cumulative revision rate for surgeons who preferred minimally stabilized arthroplasty and a 6 percent cumulative revision rate for surgeons who preferred posterior-stabilized arthroplasty. In addition, they note that the revision risk for surgeons who preferred posterior-stabilized arthroplasty was significantly higher for all causes, for loosening or lysis, and for infection, irrespective of patient age. The higher revision risk was also evident with cemented fixation, and with both cross-linked polyethylene and non–cross-linked polyethylene. However, the increased risk was only evident in male patients.

Revision ACL reconstruction—A study in AJSM (online) examines factors that may affect clinical outcomes following revision ACL reconstruction. The authors conducted a case-control study of 989 patients (median age = 26 years) undergoing revision ACL reconstruction. The median time since prior ACL reconstruction was 3.4 years. Analysis revealed the following at 2-year follow-up:

  • Compared with 1-incision technique, previous arthrotomy was linked to significantly poorer outcomes for International Knee Documentation Committee (IKDC) and KOOS pain, sports/recreation, and quality of life (QOL) subscales.
  • Use of a metal interference screw for current femoral fixation was linked to significantly better outcomes for 2-year KOOS symptoms, pain, and QOL subscales, and WOMAC stiffness subscale.
  • Not performing notchplasty at revision was linked to significantly improved outcomes for IKDC, KOOS activities of daily living (ADL) and QOL subscales, and WOMAC stiffness and ADL subscales.

Factors prior to revision ACL reconstruction associated with poorer clinical outcomes at 2-year follow-up included lower baseline outcome scores, lower Marx activity score at the time of revision, higher body mass index, female sex, and a shorter time since the patient's last ACL reconstruction.

ACL outcomes—Findings presented at the 2017 annual meeting of the American Orthopaedic Society for Sports Medicine (AOSSM) suggest that many patients experience good quality of life in the long term following ACL reconstruction. The research team reviewed prospectively collected data on 1,320 ACL reconstruction patients from the Multicenter Orthopaedics Outcome Network study. They found that the IKDC score and the KOOS significantly improved after 2 years and were maintained at 6 and 10 years. The research team notes that significant drivers of poorer outcomes were lower baseline outcome scores; higher body mass index; smoker at baseline; history of medial meniscus surgery prior to ACL reconstruction; having a revision ACL reconstruction; grades 3-4 articular cartilage pathology in the medial, lateral, and patellofemoral compartments; and having any subsequent ipsilateral surgery. The research team states that graft type, medial collateral ligament or lateral collateral ligament pathology, and medial or lateral meniscus surgery at the time of ACL reconstruction were not found to be significant risk factors.

Periarticular infiltration—A study conducted in the U.K. and published in JBJS (online) suggests that periarticular infiltration may be a viable and safe alternative to femoral nerve block for the early postoperative relief of pain following TKA. The authors conducted a pragmatic, single patient-blinded, randomized controlled trial of 230 TKA patients treated with either periarticular infiltration or femoral nerve block. They found no significant difference across cohorts in the visual analogue score for pain on postoperative day 1. Compared with patients in the femoral nerve block group, patients in the periarticular group used less morphine in the first postoperative day. The authors note that, at 6-week follow-up, the femoral nerve block group had reported 39 adverse events (27 serious) in 31 patients, while the periarticular group reported 51 adverse events (38 serious) in 42 patients. However, none of the adverse events was directly attributed to either of the interventions under investigation.

Minimally invasive lumbar spine fusion
—A study published in The Spine Journal (July) examines the use of minimally invasive lumbar spine fusion compared to an open approach. The research team conducted an observational analysis of prospective data on 1,947 patients who underwent elective interbody lumbar fusion using either a minimally invasive technique (n = 467) or a traditional open approach (n = 1,480). They found that patients in the minimally invasive cohort had reduced blood loss and a shorter length of stay for one-level fusion but an equivalent length of stay for two-level fusion compared to patients in the open cohort. However, in both unadjusted and propensity-matched comparisons, patients in both groups experienced similar return to work, patient-reported pain, physical disability, and quality of life at 3- and 12-month follow-ups.

Intermittent cervical tractionData published in Spine (July 1) suggested that intermittent cervical traction (ICT) may offer short-term relief of neck pain. The researchers conducted a meta-analysis of seven randomized, controlled trials and found that treatment with ICT was associated with significantly lower pain scores immediately after treatment compared to placebo. They also note that pain scores during the follow-up period and the neck disability index scores immediately after treatment as well as during the follow-up period did not differ significantly. However, they highlight some risks of bias in the included studies and argue that additional high-quality trials are needed to clarify the long-term effects of ICT on neck pain.

Radiofrequency denervationFindings published in The Journal of the American Medical Association (JAMA; July 4) suggest that radiofrequency denervation may not reduce pain for patients with chronic low back pain who are treated with a standardized exercise program. The research team reviewed data on 681 participants from three pragmatic, multicenter, nonblinded, randomized clinical trials on the effectiveness of minimal interventional treatments for participants with chronic low back pain who were treated with either a 3-month standardized exercise program or radiofrequency denervation plus the standardized exercise program. At 3- and 12-month follow-ups, the research team found either no improvement or no clinically significant improvement in chronic low back pain for patients who received radiofrequency denervation compared to the standardized exercise program alone. The research team states that the findings do not support the use of radiofrequency denervation to treat chronic low back pain from the sources studied (facet joint, sacroiliac joint, or a combination of facet joints, sacroiliac joints, or intervertebral disks).

Shoulder and elbow
Displaced midshaft clavicle fracture
—A study in JBJS (July 19) compares surgical and nonsurgical treatment approaches for displaced midshaft clavicle fracture. The authors conducted a prospective, randomized, controlled trial of 117 patients who received either nonsurgical treatment with a figure-of-eight harness or surgical treatment with anteroinferior plate osteosynthesis. At 6-week, 6-month, and 1-year follow-ups, they found no difference across cohorts in Disabilities of the Arm, Shoulder and Hand score, visual analog scale pain level, time to return to previous activities, or cosmetic dissatisfaction. However, the authors note that nonunion developed in seven nonsurgical patients (14.9 percent), compared to none in the surgical group. Further, nonsurgically treated patients displayed radiographic evidence of greater clavicle shortening compared with those in the surgical cohort, and more patients in that group answered "yes" when asked if their clavicle felt short and if they felt bone prominence. In the surgical group, more patients answered "yes" when asked if they felt paresthesia.

Surgeon volume—Findings from a study in the Journal of Shoulder and Elbow Surgery (July) suggest that low surgeon volume may be linked to increased surgical complications, length of stay, surgical time, and surgical cost for patients who undergo shoulder arthroplasty and rotator cuff repair. The researchers conducted a systematic review of 10 studies covering 88,740 shoulder arthroplasties and 63,535 rotator cuff repairs. For arthroplasty, they found that fewer than five cases per year met the criteria for a low-volume surgeon and that the cases were associated with increased length of stay, longer operating room time, increased in-hospital complications, and increased cost, but no significant increase in mortality. For rotator cuff surgery, fewer than 12 surgeries per year met the criteria for low volume and were associated with increased length of stay, increased operating room time, and increased reoperation rates.

RCR—A study published online in the journal Arthroscopy assesses risk of adverse events and return to the operating room (OR) during the initial 30-day postoperative period for patients undergoing open or arthroscopic rotator cuff repair (RCR). The research team reviewed information on 16,472 RCR patients from the American College of Surgeons National Surgical Quality Improvement Program database. They found that patients undergoing open RCR were more likely to be aged 65 years or older and have comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease, smoking, and alcoholism. Overall, patients undergoing open RCR had a higher risk of any adverse event when compared with arthroscopic RCR patients and were at increased risk of return to the OR within 30 days. The research team notes that open RCR was associated with a longer average hospital stay, while arthroscopic RCR was linked to a longer average operative time.

Hand and wrist
Distal radius fracture
—According to a study published in Hand (online), prompt surgery, effective fracture reduction, and careful plate positioning may help avoid volar prominence for patients who undergo volar locking plate fixation for distal radius fracture. The researchers reviewed data on 616 patients who underwent fixation for distal radius fracture. They found that mean time to surgery was 6 days. At mean 17.5-week follow-up, the researchers classified quality of reduction as anatomic (46 percent), good (36.3 percent), moderate (13 percent), or poor (3.9 percent). They found complications in 109 patients (17 percent) and observed plate prominence in 133 patients (21 percent). Flexor tendon complications were related to plate prominence, and inferior reduction was associated with increased time to surgery.

Femoral shaft fracture fixation
—A study published in PLoS Medicine (online) examines trends in the timing of femoral shaft fracture fixation following major trauma. The researchers conducted a retrospective, cohort study of 17,993 patients who underwent definitive fixation across 216 trauma centers. They found that the median time to fixation was 15 hours, with delayed fixation (≥ 24 hours) performed in 26 percent of patients. After adjustment, the researchers identified 57 hospitals (26 percent) as outliers, reflecting significant practice variation unexplained by patient case mix. Compared to hospitals in the lowest quartile of delayed fixation, patients treated at hospitals in the highest quartile experienced 2-fold higher rates of pulmonary embolism and required longer length of stay, but saw no significant difference with respect to mortality. The researchers write that "trauma centers should strive to minimize delays in fixation and quality improvement initiatives should emphasize this recommendation in best practice guidelines."

Atypical femur fracture—Findings from a study in the Journal of Orthopaedic Trauma (July) suggest that intramedullary nailing with bone marrow aspirate concentrate (BMAC) may be an effective treatment option for atypical femur fractures (AFFs). The research team conducted a retrospective case-control study of 33 AFFs treated surgically with antegrade intramedullary nails, 11 of which were treated with BMAC. They found that the overall 1-year union rate (86.2 percent) was not significantly higher in the BMAC group compared with control patients. However, BMAC use significantly decreased time to union (3.5 months versus 6.8 months), and multivariate analysis identified BMAC and varus malreduction as independent predictors of time to union. The research team note no complications linked to use of BMAC.

Alendronate—A study conducted in Sweden and published in JAMA (July 11) suggests that, for older patients using medium to high doses of prednisolone, alendronate treatment may be associated with reduced likelihood of hip fracture. The authors conducted a retrospective, cohort study of 3,604 patients with a mean age of 79.9 years. At 1.32-year median follow-up, they found that the incidence of hip fracture was 9.5 per 1,000 person-years in the alendronate cohort and 27.2 per 1,000 person-years in the no-alendronate cohort. In addition, alendronate treatment was not associated with increased risk of mild upper gastrointestinal tract symptoms or peptic ulcers. The authors state that there were no cases of incident drug-induced osteonecrosis and one case of femoral shaft fracture in each cohort.

Fracture history assessment—According to data published in the Journal of Bone and Mineral Research (online), a single bone mineral density (BMD) and fracture history assessment may help predict fracture risk over 20 to 25 years. The research team reviewed data on 7,959 women aged 67 years or older from the Study of Osteoporotic Fractures, which followed patients with hip fracture for 25 years and patients with any nonvertebral fracture for 20 years. They found that the 25-year cumulative incidence of hip fracture was 17.9 percent, and the 20-year incidence of any nonvertebral fracture was 46.2 percent. The research team notes that a single femoral neck BMD measurement strongly predicted long-term hip fracture risk to 25 years, while history of hip fracture predicted hip fractures only slightly better than history of nonvertebral fracture.

Patient safety
—A study in PLoS Medicine (online) finds no association between use of combination antimicrobial prophylaxis and a reduction in incidence of surgical site infection (SSI) for joint arthroplasty procedures. The research team reviewed data on 70,101 surgeries from a multicenter, U.S. Veterans Affairs cohort of patients who underwent cardiac, orthopaedic joint arthroplasty, vascular, colorectal, and hysterectomy procedures. Overall, 52,504 patients underwent antimicrobial prophylaxis with beta-lactam only, 5,089 with vancomycin only, and 12,508 received combination prophylaxis with both beta-lactam and vancomycin, with 2,466 incidences of SSI. After adjustment for SSI risk, the research team found that, compared to single-agent prophylaxis, combination prophylaxis was associated with a lower incidence of SSI only for cardiac surgery patients. For all other types of surgery—including joint arthroplasty—they found no link between receipt of combination prophylaxis and reduced likelihood of SSI.

Recurrent CDI—A study published in The Annals of Internal Medicine (online) notes an increase in rates of multiply recurrent Clostridium difficile infection (mrCDI). The authors conducted a retrospective cohort study of 38,911,718 commercially insured patients, 45,341 of whom developed C difficile infection (CDI). They found that, from 2001 to 2012, the annual incidence of CDI and mrCDI per 1,000 person-years increased by 42.7 percent and 188.8 percent, respectively. The increase in mrCDI incidence was independent of known risk factors for CDI. Patients in whom mrCDI developed were older, more likely to be female, and more likely to have used antibiotics, proton-pump inhibitors, or corticosteroids within 90 days of CDI diagnosis. In addition, chronic kidney disease and diagnosis in a nursing home were also associated with increased risk for mrCDI.

Antibiotics—An opinion piece published in The BMJ (online) argues that policy makers, educators, and physicians should refrain from stating that failing to complete a prescribed antibiotic course may contribute to antibiotic resistance. "[T]he idea that stopping antibiotic treatment early encourages antibiotic resistance is not supported by evidence," the writers state, "while taking antibiotics for longer than necessary increases the risk of resistance. Without explicitly contradicting previous advice, current public information materials from the U.S. Centers for Disease Control and Prevention (CDC) and Public Health England have replaced 'complete the course' with messages advocating taking antibiotics 'exactly as prescribed.'"

Sports medicine
Sport specialization
—According to findings presented at the 2017 AOSSM annual meeting, increased sport specialization may be associated with increased likelihood of lower extremity injury among younger patients. The authors recruited a diverse sample of 1,544 interscholastic high school athletes during the 2015/2016 school year, covering 2,843 athletic seasons and 167,349 athletic exposures. Overall, 60 percent of participants were classified as low specialization (based on a previously published three-item specialization scale), 27 percent moderate specialization, and 13 percent high specialization. The authors note that 235 participants (15 percent) sustained a total of 276 lower extremity injuries that caused them to miss a median of 7 days. Compared to participants with low specialization, the hazard ratio for moderately specialized participants was 1.51 and the hazard ratio for highly specialized participants was 1.85.