News in 10

The 10 items below are the most significant elements of recent editions of Headline News Now—the AAOS thrice-weekly, online update of news of interest to orthopaedic surgeons. Check this page regularly for updates.
Updated on April 1, 2014

1. Study: Patellar retraction and eversion linked to similar short-term outcomes for TKA patients.
Data from a study published in the Feb. 5 issue of The Journal of Bone & Joint Surgery suggest no early clinical benefit to retracting rather than everting the patella during total knee arthroplasty (TKA). The authors conducted a prospective, randomized, double-blinded trial of 68 patients who underwent TKA using a standard medial parapatellar approach. At 3-month and 1-year follow-ups, the authors found no significant clinical difference between retraction or eversion groups in Oxford knee score, SF-12, visual analog scale pain scores, extension, or alignment. They did note an increased percentage of lateral tibial overhang in the retraction group, but it did not correlate with functional outcome. In addition, at 1 year after surgery, no difference was found between the two groups in Insall-Salvati ratio, although a correlation between the percentage reduction in the ratio and functional outcome was noted. Finally, two partial divisions of the patella tendon occurred in the subluxation group, but no patella-related complications occurred in the eversion group.
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2. Study examines incidence rates for infection-related reoperation after arthroscopic shoulder surgery.
A study published in the February issue of The American Journal of Sports Medicine looks at infection rates associated with reoperation after arthroscopic shoulder surgery. The researchers reviewed data on 165,820 arthroscopic shoulder surgeries from a single insurer’s database. They found that 450 infections requiring additional surgery occurred, for an overall infection rate of 0.27 percent. The incidence of infections varied significantly across age groups, with the highest infection rate (0.36 percent) in patients 60 years or older, and the lowest infection rate (0.18 percent) in the 10- to 39-year age group. Incidence of infection also varied by region, with the highest incidence in the South (0.37 percent) and the lowest in the Midwest (0.11 percent). Likelihood of reoperation for infection was highest for rotator cuff repair (0.29 percent) and lowest for capsulorrhaphy (0.16 percent). Incidence did not significantly vary by year or sex.
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3. Study: Spines of children with ILBP react differently from other children under backpack load.
Data published in the Feb. 1 issue of the journal Spine suggest that typical backpack loads have a different impact on the lumbar spine of children with idiopathic low back pain (ILBP) than in children without ILBP. The authors conducted upright magnetic resonance imaging on 15 pediatric and adolescent patients with ILBP, and compared data against previously published findings. They found that, compared to normal children, children with ILBP experienced significantly less disk compression at T12–L1 to L4–L5, less lumbar lordosis, and more pain with increasing load.
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4. Study: As many as 32 percent of patients who undergo MAT may require reoperation.
A study published online in The American Journal of Sports Medicine finds a 32 percent reoperation rate for meniscal allograft transplantation (MAT) at mean 5-year follow-up (minimum 2 years). The authors conducted a retrospective review of a prospectively collected database of 172 patients who underwent MAT performed by a single surgeon between 2003 and 2011. They found that 64 patients (32 percent) had undergone surgery after their index procedure. Mean time to subsequent surgery was 21 months (range, 2-107 months), with 73 percent of subsequent surgeries occurring within 2 years of the index procedure. Simple arthroscopic debridement was the most common subsequent surgical treatment, performed in 38 of 64 patients (59 percent). Overall, eight of the 172 patients (4.7 percent) eventually required either revision MAT or total knee arthroplasty. Patients who required secondary surgery within 2 years had an odds ratio of 8.4 for future arthroplasty or MAT revision.
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5. Inpatient stay costs explain almost all of the wide variation in costs for hip, knee arthroplasty.
A research brief issued by the National Institute for Health Care Reform finds that hospital inpatient price differences account for the vast majority of spending variation on “episodes of care” rather than differences in spending on physician and other non-hospital services during and after discharge or spending on readmissions. Researchers found wide variation across institutions in the cost for hip and knee arthroplasty, with total spending for such procedures ranging from $17,000 to more than $35,000. "These spending variations appear even though the procedure and the recuperative process are fairly standardized, the population is fairly uniform (nonelderly manufacturing workers and retirees), and payments are adjusted for local input prices," the authors write. The data is based on detailed 2011 facility, professional and prescription drug claims data for current and retired autoworkers and their dependents under age 65 years, across nine markets.
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6. Study: Statins may reduce incidence of VTE in TKA, THA patients.
When statins are combined with conventional prophylactic therapy for venous thromboembolism (VTE), they significantly reduce the risk of VTE after total knee arthroplasty (TKA) and total hip arthroplasty (THA), according to data presented on Scientific Poster P204, currently on display at the AAOS Annual Meeting. Of 417 randomly selected patients who underwent TKA or THA during a 7-year period at a single institution, the control group (n = 221) was not on statin therapy, while the statin group (n = 196) had already been taking statins before surgery and continued taking hypercholesterolemia medications at the same dosage after surgery. At minimum 11-month follow-up, VTE events had occurred in 32 patients (14.5 percent) in the control cohort compared to just 15 patients (7.7 percent) in the statin group.
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7. Study: Disk herniation surgery may yield societal savings in the medium- to long-term.
Data from a study published in the April issue of the journal Clinical Orthopaedics and Related Research suggest that increased worker earnings after disk herniation surgery may offset increased medical costs associated with that surgery. The authors drew data from the National Health Interview Survey to assess the effects of lower back pain associated with disk herniation on earnings and missed workdays. They estimate that patients who undergo disk herniation surgery earn an average of $1,925 more per year than those who don’t, and miss 3 fewer days of work per year than those who are treated nonsurgically. After accounting for the effects on productivity, the authors find that disk herniation surgery yields net societal savings if the benefits of outpatient and inpatient surgery persist beyond 6 and 12 years, respectively.
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8. Study: Aseptic protocol may reduce incidence of SSI among hip arthroplasty patients.
Data from Scientific Poster P001, presented at the AAOS Annual Meeting, suggest that use of a comprehensive aseptic protocol may reduce the likelihood of surgical site infection (SSI) for high-risk patients undergoing hip arthroplasty. The researchers conducted a prospective cohort study of 774 patients undergoing primary or revision hip arthroplasty at a single center. All patients were treated with the same aseptic protocol, consisting of preoperative mupirocin nasal ointment and surgical-site chlorhexidine wipes, modified instrument care, perioperative prophylactic vancomycin and cefazolin, and surgical site skin preparation with chlorhexidine, alcohol, and iodophor. They found that the overall SSI rate among protocol patients was 0.39 percent—significantly lower than the institution’s historic rate and significantly lower than that of six previously published reports.
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9. Study: Blood biomarkers appear to indicate concussion.
According to data from a Swedish study published online in the journal JAMA Neurology, blood biomarkers may indicate concussion in athletes. The authors conducted a multicenter, prospective cohort study of 228 players in the Swedish Hockey League. They found that concussed players had increased levels of the axonal injury biomarker total tau and the astroglial injury biomarker S-100 calcium-binding protein B, compared against baseline, preseason values. The highest biomarker concentrations of total tau and S-100 calcium-binding protein B were measured immediately after a concussion, and decreased during rehabilitation. The authors detected no significant changes in levels of neuron-specific enolase from preseason to post-concussion values. The authors suggest that such factors may be developed into clinical tools to guide sports medicine physicians in return-to-play decisions.
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10. Study: ACL reconstruction associated with increased risk of OA in the long term.
Study data presented at the Specialty Day meeting of the American Orthopaedic Society for Sports Medicine suggest that adolescents who undergo anterior cruciate ligament (ACL) reconstruction may be at long-term increased risk of osteoarthritis (OA) in their injured knees. The research team evaluated 29 patients aged 12 years to 16 years who underwent reconstruction for symptomatic unilateral ACL rupture using bone-patellar bone-tendon or hamstring tendon autograft. At a mean follow-up of 14 years, 7 months, they found that reconstructed knees displayed significantly more osteoarthritic changes compared to the non-involved contralateral knee.
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