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Safe Retractor Placement during Direct Anterior THA

One of my residency mentors always stressed that orthopaedic surgeons should be “masters of musculoskeletal anatomy.” During his first lecture each July, he would grill the junior residents on muscle origins and insertions, along with innervations. Knowing safe surgical planes helps us avoid complications from neural or vascular injury and increases the likelihood of a successful orthopaedic procedure. With the increased popularity of the direct anterior approach (DAA) for total hip arthroplasty (THA), it is crucial that orthopaedists understand the anatomical implications of that technique.

One key to a successful DAA hip replacement is adequate visualization, which is aided by retractors. However, malpositioned retractors can cause femoral nerve palsy, a potentially serious neurological complication that can delay postoperative rehabilitation. In the January 15, 2020 issue of The Journal, Yoshino et al. report on a cadaveric study that quantifies the distance between the femoral nerve and the acetabular rim at varying points along the rim. Knowing these precise distances could help surgeons make safer decisions about where—and where not—to place retractors.

The authors dissected 84 cadaveric hips from 44 formalin-embalmed cadavers and measured the distance from the femoral nerve to various points along the acetabular rim by using a reference line drawn from the anterior superior iliac spine (ASIS) to the center of the acetabulum. They found the femoral nerve was closest to the rim (only 16.6 mm away) at the 90° point.

In addition, at 90°, the thickness of the iliopsoas muscle and the femoral length (a probable proxy for size of the patient) were positively associated with increased distance to the nerve. Other anatomic factors such as inguinal ligament length, femoral head diameter, and thickness of the capsule were not associated with the nerve-rim distance.

The degree nomenclature used by Yoshino et al. can be correlated to a clock-face representation of the acetabulum, with the 60° point at the 3 o’clock (anterior) position; the 30° point represents a relatively safe  location for placement of the anterior inferior iliac spine retractor (see Figure above).

This important anatomic study can help us improve our mastery of musculoskeletal anatomy—and avoid, if possible, placement of retractors at 90° relative to a line drawn from the ASIS to the center of the acetabulum.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

Strong Case for Outpatient Fracture Surgery

Nobody wants to be hospitalized. Hospitals are expensive, risky, and noisy environments, providing probably the worst set-up for restorative sleep. Add to that the issue of health care costs, and it becomes imperative to investigate ways to identify patients and procedures that can be safely moved to the outpatient environment.

Addressing that imperative was the aim of a time-series study in the January 15, 2020 issue of The Journal by Wolfstadt et al. The authors report on the success of a streamlined pathway for safely shifting less-urgent fracture cases to an outpatient environment.

Using the interventions described in the study, a large, urban academic hospital in Canada increased the percentage of fracture patients managed as outpatients from 1.6% pre-intervention to 89.1% post-intervention. None of the >300 patients had a readmission during the intervention period, and there were no complications while patients waited for surgery at home. Although the average time-to-surgery increased to 48 hours after the pathway was implemented, the extra time waiting at home did not negatively affect patient-satisfaction scores.

On the cost/resource side, the hospital estimated that conversions to outpatient care in these patients led to an annual reduction in operating costs of nearly $240,000 CAD. The hospital used the bed capacity freed up by the outpatient fracture pathway to increase its volume of elective hip and knee replacements.

It has been suggested that 90% of orthopaedic procedures can be safely performed in non-hospital environments. Wolfstadt et al. emphasize that successfully doing so requires extra patient education, a team-based and patient-centered culture, and support from hospital administrators.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

More Data on Managing Distal Radial Fractures in Old Patients

Distal radial fractures are common, especially in the elderly, but the best management for these fractures in older patients remains controversial. Clinical practice guidelines issued in 2011 by the AAOS recommend operative treatment when certain angulation and shortening criteria are met. Meanwhile, some studies show that age >65 years is an independent risk factor for poor radiographic outcomes,1 while other studies suggest that older patients have acceptable functional outcomes despite radiographic loss of reduction.2 We may want to believe that anatomic reduction and normal-appearing radiographs will ensure improved outcomes, but the science has not always confirmed that connection, leaving us and our older patients in a bit of a conundrum.

In the January 2, 2020 issue of The Journal, DeGeorge et al. tackle this subject in a large retrospective analysis of data from patients ≥65 years old who had been managed for a distal radial fracture between 2009 and 2014. Among >13,000 distal radial fractures analyzed, 9,973 were treated nonoperatively and 3,740 were treated operatively. The average age of the entire cohort was 75.4 years, but the authors found that the operative group was significantly younger, and that nonoperative treatment was more commonly performed in patients with a greater number and severity of medical comorbidities, including cardiovascular disease, diabetes, cancer, and dementia.

At 90 days, the overall complication rate was low (36.5 complications per 1,000 fractures), and the authors found no significant differences between the operative and nonoperative groups. However, the complication rate at 1 year was significantly higher in the operative group (307.5 per 1,000 fractures) compared to the nonoperative group (236.2 complications per 1,000 fractures). Stiffness was the most common complication across both groups, but it was significantly more common in the group that underwent operative management (occurring in 16% of that cohort). Also of note: approximately 10% of patients in each group developed chronic regional pain syndrome.

Despite the inherent weaknesses in retrospective database analyses (including, in this case, the inability to analyze indications for surgery), this study reveals some important facts that may help us better counsel older patients. Operative management of distal radial fractures in the elderly may yield better radiographic outcomes than nonoperative treatment, but that comes with a significantly increased risk of 1-year complications. Accepting a less-than-perfect reduction on radiographs and casting the fracture may be more beneficial than surgery for many of our elderly patients.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

References

  1. Mackenny PJ, McQueen MM, Elton R. Prediction of instability in distal radius fractures. J Bone Joint Surg Am. 2006 Sep; 88(9):1944-1951.
  2. Grewal R, MacDermid JC. The risk of adverse outcomes in extra-articular distal radius fractures is increased with malalignment in patients of all ages but mitigated in older patients. J Hand Surg Am. 2007 Sep; 32(7):962-70.

Editor’s Note: Here is a list of previous OrthoBuzz posts about managing distal radial fractures:

Whence SCFE? More Hints Here

Pediatric orthopaedists have long been searching for anatomic, mechanical, and metabolic causes of slipped capital femoral epiphysis (SCFE). Adolescent obesity has been a recognized SCFE risk factor for 50 years. (Interestingly, high BMI is a consistent risk factor in males, but females who experience SCFE are often thin.) Possible racial risk factors have been examined as well, with no clear conclusions.

Because the incidence of SCFE is relatively low (1 in 10,000 children according to this JBJS Clinical Summary) and the risk of bilaterality is high (in the range of 30% to 40%), it seems likely that anatomic risk factors are at play. In the January 2, 2020 issue of The Journal, Novias et al. home in on the 3-D anatomy of the epiphyseal tubercle (a small, round protuberance thought to stabilize the epiphysis) and peripheral “cupping” of the epiphysis in patients with and without SCFE.

They found a smaller epiphyseal tubercle and more extensive epiphyseal cupping in patients with SCFE compared with normal hips. The authors encourage further investigation of the first finding to determine whether smaller tubercles are a consequence of the slip process or an anatomic variant that predisposes the epiphysis to slip.

A major strength of this study is that all measurements were made by a single observer blinded to the diagnosis of SCFE and other potentially confounding clinical and demographic data. Also, the measurement processes used in this study have been previously validated.

Investigation into the anatomic features of this disease should continue, along with development of minimally invasive, safe, and inexpensive ways to screen for possible anatomic risk factors. The most pertinent clinical goals are to  continue evolving minimally invasive methods of epiphyseal stabilization to prevent and/or treat SCFE and to more accurately identify hips at risk of SCFE.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Vancomycin-Soaked ACL Grafts Cut Already-Low Infection Rates

The word “infection” contains 9 letters, but it’s a four-letter word for orthopaedic surgeons. Postoperative infections are complications that we all deal with, but we try hard to avoid them. Infections after elective sports surgeries can have especially devastating long-term consequences. Thankfully, scientific advances such as  improved sterile techniques and more powerful prophylactic antibiotics have helped us decrease the rates of perioperative infections. But more can always be done in this arena.

Baron et al. discuss one additional infection-fighting approach in the December 18, 2019 issue of JBJS, where they report on findings from a retrospective cohort study that looked at 90-day infection rates after >1,600 anterior cruciate ligament (ACL) reconstructions. Specifically, they investigated whether the rates of infection differed when the ACL grafts were prepared with or without a vancomycin irrigant. The average patient age was 27 years old, and all the surgeries (84.1% of which were primary reconstructions) were performed by 1 of 6 fellowship-trained surgeons. The graft was soaked in vancomycin solution in 798 cases (48.7%), while the remaining 51.3% did not use vancomycin.

Baron et al. found that 11 of the reconstructions were complicated by infection within 90 days, but only 1 of those 11 infections occurred in the vancomycin group (p=0.032). After controlling for various confounding factors, the authors found that increased body mass index and increased operative time were also significantly associated with postoperative infection, while age, sex, smoking, surgeon, and insurance type were not.

These results reveal an 89.4% relative risk reduction in postoperative infections after ACL reconstructions when grafts are bathed in vancomycin solution, although the absolute rate of infection among non-soaked grafts (1.2%) was still quite low. Time and more rigorous study designs will tell us whether this is a big step forward in the evolution of infection prevention, but these results should at least prompt further investigation.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

Total Ankle Arthroplasty: Maybe Not as Finicky as We Thought?

As the orthopaedic community continues to solve complex issues related to joint replacement, it has become apparent that deformity correction and component positioning are keys to long-term success. In terms of hip, knee, and shoulder arthroplasty, we have progressed throughout the last 50 years with improved functional outcomes and component longevity. Elbow arthroplasty development has lagged somewhat because indications for that procedure are much less common.

Meanwhile, total ankle arthroplasty (TAA) experienced a short-lived decade of enthusiasm in the late 1970s and early 1980s before it became apparent that improved component designs and surgical techniques were needed. Progress with TAA stalled until the late 1990s, but TAA has now become more predictable, and several successful designs are available with reasonable revision rates demonstrated during 10-plus years of follow-up. As with all arthroplasties, component alignment in TAA is critical, and we have therefore assumed that significant preoperative frontal plane deformity is a contraindication for this procedure.

However, in the December 18, 2019 issue of The Journal, Lee et al. challenge that assumption with midterm follow-up data on 146 TAAs that suggest patients with frontal plane deformities >20° should not necessarily be disqualified from having this procedure. In this study, prior to surgery, 107 ankles had moderate frontal plane deformity (5° to <15° of varus or valgus) and 41 ankles had severe deformity (>20° to 35° of varus or valgus). The authors found no difference between these groups in terms of functional outcomes, complications, or implant survival at a mean follow-up of 6 years. Lee et al. conclude that frontal malalignment >20° in patients with end-stage ankle osteoarthritis may not be a contraindication to proceeding with TAA. However, the authors emphasize that concomitant realignment procedures at the time of index arthroplasty (including ligament releases and corrective osteotomies) were much more common in the severe group.

These findings need confirmation from other groups and with longer-term follow-up so that data from lower-volume surgeons can be analyzed and later complications can be investigated. Still, it just may be that ankle arthroplasty is not as finicky as we have been thinking.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

RCT: Single IV Dose of TXA Is Safe, Effective for TKA

Along the spectrum of early and late adopters in medicine, most orthopaedic surgeons fall in the middle. They wait for science to prove the efficacy and safety of an innovation, carefully review the published studies regarding that innovation, and adopt it if it will improve their patients’ outcomes.

In the December 4, 2019 issue of JBJS, Jules-Elysee et al. compare tranexamic acid (TXA) administered intravenously (IV) versus topically in a double-blinded, randomized controlled trial (RCT) of patients undergoing primary total knee arthroplasty (TKA).  Level-I evidence is rare in the orthopaedic literature, so when a well-performed RCT comes out, we should closely evaluate its findings.

A potent antifibrinolytic, TXA has been shown in multiple studies to decrease blood loss associated with major orthopaedic procedures. However, there are persistent (but not necessarily evidence-based) concerns about its potential to cause thrombogenic complications,  and the safest and most effective route of TXA administration remains an open question.

In this study, the IV group received TXA once before tourniquet inflation and again 3 hours later, along with a topical placebo given 5 minutes before tourniquet release.  The topical group received an IV placebo at the same time intervals as the IV group, along with TXA delivered topically in the wound prior to tourniquet release. The authors found lower systemic levels of plasmin-anti-plasmin (PAP, a measure of fibrinolysis) in both groups 1 hour after tourniquet release, but PAP levels remained significantly lower in the IV group (indicating higher antifibrinolytic activity) 4 hours after tourniquet release, which was likely related to the second IV dose of TXA.

The authors also found no between-group difference in systemic or wound levels of prothrombin fragment 1.2 (PF1.2, a marker of thrombin generation), indicating there was no increase in thrombogenicity in the IV group.  Interestingly, Jules-Elysee also found that the IV group had significantly higher hemoglobin and hematocrit levels 1 and 2 days after surgery, and those patients had a significantly shorter hospital stay.

Finding no major between-group differences in the mechanism of action, coagulation, or fibrinolytic profile, the authors concluded that a single IV dose of TXA may be the most simple protocol for hospitals to adopt if they are still concerned about TXA safety. Perhaps these Level-I findings will help some of the late adopters get over their fears about the safety of IV TXA.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

Meta-Analysis Quality Improving, But Issues Remain

Hip and knee arthroplasty are common procedures worldwide and are increasing annually as demographics change and the technical aspects of these surgeries become more accessible to a broader swath of surgeons. The sheer number of these procedures makes them an appropriate focus for randomized controlled trials (RCTs). The aggregation of RCT data into more powerful statistical frameworks is the job of a meta-analysis.

Not surprisingly, we have seen an increasing number of meta-analyses related to hip and knee replacement published across all major orthopaedic journals during the last two decades. Authors have two common motivations for conducting meta-analyses. The first, to summarize data from carefully conducted RCTs into clinically relevant and important recommendations, is hopefully the most common motivation—and certainly the most justifiable. The second, to merely use previously published data as an analytic exercise to advance one’s academic career without investing the time and effort to do prospective research, is not justifiable, in my estimation.

In the December 4, 2019 issue of The Journal, Park et al. conduct quality and usefulness assessments of 114 published meta-analyses about hip and knee arthroplasty that appeared in 3 major orthopaedic journals (one of which was JBJS) from 2000 to 2017. They document a nearly 4-fold increase in the number of meta-analyses published on these topics when comparing 2000 to 2009 with 2010 to 2017. Based on Oxman-Guyatt Index scores of overall study quality, only 12 of the 114 studies were assessed as high quality, 87 as moderate quality, and 15 as low quality.

Here are some additional findings:

  • The majority of these meta-analyses were not performed in accordance with established PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.
  • Only 39% of these articles showed the risk of bias.
  • Many of these meta-analyses covered redundant topics within the same year or within a few years of each other.
  • A review by expert attending surgeons of the 24 studies determined to be high quality per PRISMA found that 71% were either clinically unimportant or inconclusive.

It is a positive step to highlight for our readers the important quality issues surrounding meta-analyses, and I agree with James Stoney, who commented on these findings: “The onus is on surgeons to carefully scrutinize meta-analyses…and come to individual conclusions about the quality of the research rather than accept the conclusions at face value.”

But I am discouraged to see the number of problematic meta-analyses that have appeared in our literature, and I suspect most of these quality problems arise from the second, unjustifiable motivation noted above. We need to do better as a research community, as peer reviewers, and as journal editors to improve the quality of published meta-analyses so that we can favorably impact patient care and advance the clinical practice of hip and knee arthroplasty.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

“Homemade” Negative-Pressure Wound Device Works as Well as Commercial NPWT

Innovation in medicine has brought innumerable improvements in patient care. For example, as late as the Vietnam War era, femoral shaft fractures were frequently treated with prolonged periods of traction—until intramedullary rods gained popularity because they helped patients mobilize soon after the injury. Similarly, negative-pressure wound therapy (NPWT) gained popularity in the 1990s because it was so helpful with treating open wounds in orthopaedics. NPWT has been a mainstay in the treatment of Wounded Warriors with blast injuries during the last 18 years of conflicts in Afghanistan, Iraq, and other war zones. But medical innovations such as NPWT often come with a high cost, which has made access to commercial NPWT unfeasible in many low-income, resource-challenged countries. Sadly, those places are also home to many patients who sustain devastating soft-tissue injuries.

In the November 20, 2019 issue of JBJS, Cocjin et al. from the Philippines report results from a randomized controlled trial that compared 7-day outcomes from a commercially available NPWT system to those from an innovative, low-cost system that the authors developed locally and have been using at their institution since the mid-2000s. This home-grown system consists of an aquarium pump converted into a reusable vacuum source, along with basic hospital supplies such as surgical gauze, tubing, and plastic food wrap. The authors also compared the cost of the two systems.

For most of the measured clinical outcomes, Cocjin et al. found that their innovative NPWT system was noninferior to the commercially available system. It was actually better (but not significantly so) in terms of time of application, pain during dressing changes, and wound-contraction percentages. There were no complications with either system, and the system made from the aquarium pump and hospital supplies cost 7 times less than the commercial device ($63.75 compared to $491.38 USD).  The converted aquarium-pump system can be used up to 20 times, making its per-use cost as low as $3.

Innovation is vital to advancing orthopaedics. But we must also remember that low-cost innovation is equally important for a large portion of the worldwide patient and provider population that is resource-constrained. I applaud Cocjin et al. for sharing their locally developed innovation with the wider orthopaedic community. Although further validating studies are needed, this “homemade” NPWT system has the potential to bring to a large portion of the world a cost-effective alternative to a wound-management technique that has become a mainstay in more affluent settings over the past 2 decades.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

The Evolution of Orthopaedic Surgical Skills Simulation

Surgical skills education in orthopaedics has changed dramatically from the “see one, do one, teach one” process of 30 years ago. These changes have come with a greater degree of supervision and formal skills assessments, and they have been aided by the visionary leadership at the Accreditation Council for Graduate Medical Education (ACGME) and our own orthopaedic Residency Review Committee. These skill-acquisition enhancements have benefited both our trainees and the patients we collectively care for.

A decade ago, we entered a new phase of skill development and enhancement with computer-based surgical simulators. With advances in software and widespread interest across North America in goal-driven learning through simulation, great progress has been made. In the November 20, 2019 issue of JBJS, Weber et al. report on the further validation of a surgical simulator focused specifically on percutaneous, fluoroscopically guided pin placement for femoral neck fractures. The simulator was developed in partnership between the AAOS and OTA.

This study sought to determine whether novice practitioners (medical students, in this case) who completed 9 training modules before using the simulator (the “trained” group) would perform the simulated pinning task better than peers who did not complete the presimulation training (the “untrained” group). It was no surprise to me that the trained group had a significantly higher overall performance score on the simulator. In addition, relative to the untrained group, the trained students also showed improved performance on 4 specific measures—3 of which were related to the angle between the placed pins.

These findings are clearly supportive of continued development of this and additional simulation environments. But at the same time, we need to move forward with improved documentation of surgical skill acquisition among orthopaedic residents and fellows. As simulator technology continues to improve, the next decade should yield even more positive results in skills acquisition than we saw in the last decade. We are clearly on the right path with the use of advanced technology for surgical skill development among orthopaedic trainees.

Marc Swiontkowski, MD
JBJS Editor-in-Chief