AAOS Now

Published 11/1/2016

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
Vancomycin powder—According to a study in the Journal of Orthopaedic Trauma (JOT; October), early application of vancomycin powder may help prevent infection in traumatic wounds. The authors used an established segmental defect rat femur model contaminated with Staphylococcus aureus UAMS-1 followed by treatment at 6 or 24 hours postinfection. They evaluated three treatments: débridement and irrigation alone, and in combination with either vancomycin powder or vancomycin-impregnated polymethyl methacrylate beads. They found that locally applied vancomycin powder and impregnated beads significantly reduced bacteria within both the bone and implant when treatment was performed at 6 hours. However, delaying treatment to 24 hours significantly reduced the therapeutic efficacy of locally applied vancomycin in both groups. They note that at 14 days, vancomycin was detectable in the surrounding musculature of all animals and in serum of 20 percent of those treated with vancomycin powder.

Nonunion—A study published in JAMA Surgery (online) examines the relationships among fracture characteristics, patient-related risk factors, and risk of fracture nonunion. The authors reviewed data from a large payer database on 309,330 fractures across 18 bones. They found that the overall nonunion rate was 4.9 percent. Increased risk of nonunion was associated with severe fracture (eg, open fracture, multiple fractures), high body mass index, smoking, and alcoholism. Overall, women experienced more fractures, but men were more prone to nonunion. Scaphoid, tibia plus fibula, and femur fractures were most likely to experience nonunion. Additional risk factors for nonunion included use of nonsteroidal anti-inflammatory drugs plus opioids, surgical treatment, anticoagulant use, osteoarthritis (OA) with rheumatoid arthritis, anticonvulsant use with or without benzodiazepines, opioid use, diabetes or insulin use, osteoporosis with or without medication use, antibiotic use, vitamin D deficiency, diuretic use, and renal insufficiency.

Hip and knee
Hip arthroscopy—A study published online in The American Journal of Sports Medicine (AJSM; online) examines survival and clinical outcomes for patients who undergo hip arthroscopy. The authors prospectively collected data on 931 primary hip arthroscopy procedures and 107 revision hip arthroscopy procedures at a single center. At 2-year follow-up, they found significant improvement in outcome scores (modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sport-Specific Subscale, and visual analog scale) for patients in both cohorts. Overall, patient-reported outcome scores were higher at all time points for the primary group compared with the revision group, and mean satisfaction was 7.7 in the primary cohort and 7.2 in the revision cohort. Of 931 primary arthroscopic procedures, 52 (5.6 percent) were converted to total hip arthroplasty (THA) or hip resurfacing (HR), and the relative risk of THA/HR was 2.0 after revision procedures compared with primary procedures. The researchers write that the overall complication rate was 4.3 percent.

Hyaluronic acid—A study published in The Journal of Bone & Joint Surgery (JBJS; Sept. 7) finds that hyaluronic acid (HA) injections continue to be used to treat knee OA in patients with end-stage OA, despite concerns regarding their efficacy and cost-effectiveness. The researchers reviewed information on 244,059 patients with end-stage OA who underwent total knee arthroplasty (TKA) from 2005 to 2012. Of those, 35,935 (14.7 percent) had at least one HA injection in the 12 months preceding TKA. They note that HA injections were responsible for 16.4 percent of all knee OA-related payments, and that HA injections accounted for 25.2 percent of treatment-specific payments—a rate higher than that of any other treatment. "A decrease in the use of HA injections in end-stage knee osteoarthritis could reduce the overall health-care cost burden," the researchers write, "potentially without causing an adverse effect on outcomes."

Computer-assisted surgery—Findings from a study published in Clinical Orthopaedics and Related Research (CORR; October) suggest that computer-assisted surgery (CAS) for cup placement may not be associated with substantial advantage in function, wear rate, or survivorship at 10 years after THA. The authors conducted a randomized, controlled trial of 60 patients who underwent THA using either CAS or conventional technique for cup placement. At 10-year follow-up, no significant differences were found between cohorts in Harris Hip Score, acetabular linear wear, or survivorship free from aseptic loosening.

Shoulder and elbow
Rotator cuff tear—Data published in the Journal of Orthopaedic Research (September) emphasize a need for care in performing subacromial lidocaine injections to treat rotator cuff tears. The researchers examined the effect of lidocaine on torn rotator cuff tendons in vitro (human tendons) and in vivo (rat tendons). They found that cell viability decreased after exposure to 0.1 percent lidocaine for 24 hours. At 2 and 4 weeks following surgery, the ultimate load to failure decreased more in the lidocaine group than in the control group, with significantly reduced stiffness in the lidocaine group 2 weeks after surgery. In addition, collagen organization significantly decreased in the lidocaine group by 4 weeks after surgery but returned to baseline at 8 weeks. Further, lidocaine caused cytotoxicity to tenocytes under both conditions, decreased biomechanical properties, and induced apoptosis and delay of collagen organization.
Foot and ankle
Total ankle arthroplasty—A study published in JBJS (Sept. 7) suggests lower complication rates for total ankle arthroplasty (TAA) compared to primary ankle arthrodesis. The authors reviewed a state database of hospital discharges and identified 8,491 ankle arthrodesis procedures and 1,280 TAAs. They found that short-term complication risk was low for both procedures, but that patients who received TAA had significantly lower rates of readmission and periprosthetic infection compared with patients who had ankle arthrodesis. Overall, TAA patients were more likely to be female, white, and older, and to have Medicare or private health insurance compared to fusion patients.

Hand and wrist
Dupuytren disease—A study conducted in Sweden and published in The Journal of Hand Surgery (September) finds no significant difference in outcomes between collagenase and needle fasciotomy treatment for contracture of the metacarpophalangeal (MCP) joint in Dupuytren disease. The authors conducted a prospective, single-blinded, randomized study of 140 patients with an MCP contracture of 20 degrees or more in a single finger, who were treated with collagenase (n = 69) or needle fasciotomy (n = 71). At 1-week follow-up, the authors found that 88 percent of patients in the collagenase cohort and 90 percent of patients in the needle fasciotomy cohort displayed a reduction in MCP contracture to less than 5 degrees, and median gains in passive MCP movement were 48 degrees and 46 degrees, respectively. Overall median visual analog scale score for procedural pain was 4.9 of 10 in the collagenase group and 2.7 of 10 in the needle fasciotomy group. At 1-year follow-up, 90 percent of patients in both groups had full extension of the treated MCP joint, and one patient in each group had a recurrence of the contracture.

Sports medicine
Concussion—According to a study in Pediatrics (August), younger athletes may recover from sport-related concussion more quickly if they are removed from participation. The research team conducted a prospective study of 35 athletes who were immediately removed from play and 34 athletes who continued to play following concussion. They found that patients who continued to play took significantly longer to recover and were 8.8 times more likely to demonstrate protracted recovery (defined as 21 days or longer). Overall, return to play status was associated with the greatest risk of protracted recovery compared with other predictors. In addition, athletes who continued to play exhibited significantly worse neurocognitive and greater symptoms than those who were removed from play.

Return-to-play—A study published in AJSM (online) examines the career effect of certain orthopaedic procedures performed on National Football League (NFL) athletes. The researchers conducted a case series study of 559 NFL players who underwent procedures for anterior cruciate ligament (ACL) tear, Achilles tendon tear, patellar tendon tear, cervical disk herniation, lumbar disk herniation, sports hernia, knee articular cartilage repair (microfracture technique), forearm fracture, tibial shaft fracture, or ankle fracture. They found that 79.4 percent of athletes returned to play following the procedure. The researchers note that forearm open reduction and internal fixation (ORIF), sports hernia repair, and tibia intramedullary nailing (IMN) were associated with significantly higher return-to-play rates, compared to patellar tendon repair. Overall, athletes who underwent ACL reconstruction, Achilles tendon repair, patellar tendon repair, and ankle fracture ORIF displayed significant declines in games played at 1 year, but recovered to baseline at 2 to 3 years following surgery. Athletes undergoing ACL reconstruction, Achilles tendon repair, patellar tendon repair, and tibia IMN displayed decreased performance in postoperative season 1; athletes in the Achilles tendon repair and tibia IMN cohorts recovered to baseline performance, while those in the ACL reconstruction and patellar tendon repair cohorts did not.

Trauma
Warfarin—Findings published in CORR (online) suggest that warfarin therapy at time of injury may be linked to increased time to surgery, length of stay, and decreased survival for certain femur fracture patients. The authors reviewed data on 1,979 patients who presented with a fractured neck of the femur at a single center. Compared to patients not taking warfarin, the authors found that those taking warfarin were less likely to go to surgery by 36 hours and by 48 hours. In addition, patients taking warfarin had a longer median length of stay and increased risk of 12-month mortality.

IMN insertion technique—According to a study published in JOT (October), use of the suprapatellar intramedullary nail insertion technique may be linked to a lower rate of malalignment compared with the infrapatellar IMN technique. The researchers conducted a retrospective cohort study of 266 skeletally mature patients with distal tibia fracture who were seen at one of two centers; 132 patients were treated through a suprapatellar technique. Cohorts were matched with respect to age, gender, fracture grade, and presence of open fracture. The researchers found that primary angular malalignment of ≥ 5 degrees occurred in 26.1 percent of patients (n = 35) with infrapatellar IMN insertion and in 3.8 percent of patients (n = 5) who underwent suprapatellar IMN insertion.