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The Risk of Vascular Injury During Hip-Fracture Fixation

According to the orthopaedic literature, the risk of vascular injury during internal fixation of a proximal femoral fracture is low. But applying the findings from an anatomical analysis by Jaipurwala et al. in the November 6, 2019 issue of The Journal of Bone & Joint Surgery could help minimize that risk even further.

The authors examined lower-limb CT angiograms of 47 patients (mean age 69) who had the scans performed for reasons other than a femoral fracture. They then measured the distance from the tip of the greater trochanter to the profunda femoris artery and its perforators within 5 mm of the medial femoral shaft, along the length of typical placement of dynamic hip screws used for fixation of proximal femoral fractures. (The authors assumed the use of a 4-hole, 78 mm plate or a 6-hole, 110 mm plate.)

All 47 patients had 2 vessels within 5 mm of the medial femoral shaft along the line of presumed dynamic hip screw insertion. Noting that these vessels could be damaged by reduction instruments or during drilling and plate-screw insertion during actual cases of femoral-fracture fixation, Jaipurwala et al. make the following suggestions:

  • Avoid or take special care when drilling or inserting screws along the femoral shaft from 110 to 120 mm from the tip of the greater trochanter in women and from 120 to 130 mm in men.
  • If possible, avoid inserting a screw in the fourth hole of a 4-hole dynamic hip screw plate or inserting a screw in the fourth and fifth holes of a 6-hole plate.

The authors emphasize that these suggestions are based on measurements taken from patients who did not have a hip fracture and that “a femoral fracture may potentially alter local anatomy because of swelling and damage to surrounding structures.” But they conclude that the risk of vascular injuries in patients with a proximal femoral fracture would be further reduced if surgeons took these findings into account during operative planning and execution of hip-fracture fixation.

Hemi vs THA Findings Helpful, But Not Practice-Changing

OrthoBuzz occasionally receives posts from guest bloggers. In response to a recent study in The New England Journal of Medicinethe following commentary comes from Paul E. Matuszewski, MD.

A recent issue of The New England Journal of Medicine published the results from a large, multicenter randomized trial comparing the outcomes of hemiarthroplasty versus total hip arthroplasty (THA) to treat displaced femoral neck fractures in ambulatory adults.

The HEALTH investigators enrolled 1,495 patients in the study, and 85.1% of those patients had complete data for analysis after 2 years. The researchers found no significant differences between the groups with regard to the primary outcome—secondary hip procedures (7.9% in the THA group vs 8.3% in the hemi group). The risk of secondary hip procedures during the first year was higher in the THA group, but the hemiarthroplasty group had a higher risk of secondary procedures in the second year. Open/closed reductions of hip dislocations were the most common secondary procedures among the THA group, and revision to THA was the most common secondary procedure in the hemiarthroplasty group. The THA group had slightly better WOMAC scores, but the difference was not within a clinically significant range. There were no between-group differences noted in other patient-reported outcomes.

The HEALTH investigators followed these patients for only two years, which is notably the standard for many orthopaedic studies, but this short follow-up limits the practical application of these findings. The authors note that after the first year, primary THA was favorable with regard to secondary hip procedures. It is reasonable to think that this difference may become more compelling beyond 2 years, as more patients who received hemiarthroplasty are likely to be converted to THA.

The suggestion that there may not be an early benefit of THA over hemiarthroplasty in the ambulatory adult with a displaced femoral neck fracture contrasts with current recommendations from the American Academy of Orthopaedic Surgeons. However, the 2-year follow-up of this trial represents only a “snapshot” of the continuum of outcomes from these two hip-fracture treatments. The findings may add to our understanding of what our patients can expect during the first 2 years following these procedures, but I would caution surgeons against making any drastic changes to their current practice in response to this data.

Paul E. Matuszewski, MD is the Director of Orthopaedic Trauma Research and Assistant Professor of Orthopaedic Traumatology at the University of Kentucky.

Language Processing Algorithms Can Boost Orthopaedic Research

Manufacturing, farming, and shopping…These are just 3 diverse examples of how technology is advancing daily and automating tedious tasks, decreasing costs, and improving efficiencies. Orthopaedics and orthopaedic research are not being left behind in this progression. In the November 6, 2019 edition of JBJS, Wyles et al. evaluate the accuracy of natural language processing (NLP) tools in automating the extraction of orthopaedic data from electronic health records (EHRs) and registries. The findings suggest that NLP-generated algorithms can indeed reliably extract data without the labor-intensive and costly process of manual chart reviews.

First, using an open-source NLP “engine,” the researchers developed NLP algorithms focused on 3 elements of >1,500 total hip arthroplasty (THA) procedures captured in the Mayo Total Joint Registry: (1) operative approach, (2) fixation technique, and (3) bearing surface. They then applied the algorithm to operative notes from THAs performed at Mayo and to THA-specific EHR data from outside facilities to determine external validity.

Relative to the current “gold-standard” of manual chart reviews, the algorithm had an accuracy of 99.2% in identifying the operative approach, 90.7% in identifying the fixation technique, and 95.8% in identifying the bearing surface. The researchers found similar accuracy rates when they applied the algorithm to external operative notes.

The findings from this study strongly suggest that properly “trained” NLP algorithms may someday eliminate the need for manual data extraction. That, in turn, could substantially streamline future research, policy, and surveillance tasks within orthopaedics. As Gwo-Chin Lee, MD predicts in his Commentary on this study, “When perfected, NLP will become the gold standard in the initial data mining of patient records for research, billing, and quality-improvement initiatives.” Dr. Lee is quick to add, however, that “no machine learning can occur…without the integral and indispensable input of the human element.”

Orthopaedic surgeons are already using robots to assist them in performing total joint arthroplasties. Wyles et al. show how we can use technology to reliably expedite research on that same subject. I believe the future holds much promise for the use of ever-advancing technologies in orthopaedic surgery and research.

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

Association ≠ Causation: Are Steroid Injections for OA Risky?

A recent report in Radiology citing possible complications from injecting steroids into painful joints with osteoarthritis (OA) has received lots of attention in the mainstream media. Radiologists from Boston, Germany, and France reviewed the existing literature and found an association between intra-articular steroid injections and a small increased risk of four adverse joint findings: accelerated OA progression, subchondral insufficiency fracture, complications from osteonecrosis, and bone loss. However, the study did not include a control group that did not receive injections, and therefore it cannot be used to assess whether injections are associated causally with the adverse joint findings.

In an interview with Boston radio station WBUR, lead author Ali Guermazi, MD stressed the point that readers should not conclude from this report that steroid injections cause these complications, adding that additional research in this area is “urgently needed.” In the same radio coverage, Jeffrey Katz, MD, a professor of orthopaedic surgery at Boston’s Brigham & Women’s Hospital and a Deputy Editor at JBJS, said patients who have received such injections or plan to should not be overly worried. However, he added that “for clinicians and patients who’ve been doing injections for several years, it’s worth it to pause and say, ‘Do we want to discuss [again] what we think are the benefits and risks of this.’”

What’s New in Hip Replacement 2019

Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries. This month, Mengnai Li, MD, co-author of the September 18, 2019 “What’s New in Hip Replacement,” selected the five most clinically compelling findings from among the more than 100 studies summarized in the article.

THA Dislocation
–Pathology involving the spinopelvic relationship has dominated the recent literature on THA dislocation. For patients presenting with a flatback deformity and stiff spine, who had the highest risk of dislocation, the authors of a recent study suggested the use of a dual-mobility implant construct with targeted 30° of anteversion relative to the functional pelvic plane, based on a standing anteroposterior radiograph.1

Preferred Implant Designs
–A study comparing data from the American Joint Replacement Registry with national registry data from other countries found that cementless stem fixation with the use of ceramic and 36-mm heads was the current US preference, while non-US registries indicated that cemented implants and metal and 32-mm heads were used most commonly.2

Opioid Use
–The ongoing effort in the orthopaedic community to reduce opioid consumption without compromising quality of life for joint-replacement patients may be aided by findings from a recent randomized controlled trial. The study found that prescribing 30 immediate-release oxycodone pills instead of 90 pills was associated with a significant reduction in unused pills and decreased opioid consumption without affecting pain scores and patient-reported outcomes.3

Penicillin Allergy
– A retrospective review of >4,900 patients who underwent THA or TKA found that 16.2% reported a history of penicillin allergy. No patients among those with a stated penicillin allergy who were given cefazolin had an adverse reaction. Also, there was no increased rate of surgical site infections among those with a stated penicillin allergy who received clindamycin or vancomycin, although the authors acknowledged that this part of the study was underpowered due to the low overall rate of infection.4

Use of TXA
–Recent guidelines on the use of tranexamic acid (TXA) state that no specific routes of administration, dosage, dosing regimen, or time of administration have been shown to provide clearly superior blood-sparing properties.5

References

  1. Luthringer TA, Vigdorchik JM. A preoperative workup of a “hip-spine” total hip arthroplasty patient: a simplified approach to a complex problem. J Arthroplasty.2019 Jan 18. [Epub ahead of print].
  2. Heckmann N, Ihn H, Stefl M, Etkin CD, Springer BD, Berry DJ, Lieberman JR. Early results from the American Joint Replacement Registry: a comparison with other national registries. J Arthroplasty.2019 Jan 5.
  3. Hannon CP, Calkins TE, Li J, Culvern C, Darrith B, Nam D, Gerlinger TL, Buvanendran A, Della Valle CJ. The James A. Rand Young Investigator’s Award: large opioid prescriptions are unnecessary after total joint arthroplasty: a randomized controlled trial. J Arthroplasty.2019 Feb 4. [Epub ahead of print].
  4. Stone AH, Kelmer G, MacDonald JH, Clance MR, King PJ. The impact of patient-reported penicillin allergy on risk for surgical site infection in total joint arthroplasty. J Am Acad Orthop Surg.2019 Feb 27. [Epub ahead of print].
  5. Fillingham YA, Ramkumar DB, Jevsevar DS, Yates AJ, Bini SA, Clarke HD, Schemitsch E, Johnson RL, Memtsoudis SG, Sayeed SA, Sah AP, Della Valle CJ. Tranexamic acid use in total joint arthroplasty: the clinical practice guidelines endorsed by the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society. J Arthroplasty.2018 Oct;33(10):3065-9. Epub 2018 Aug 7.

Who’s at Risk for Prolonged Opioid Use after THA?

Much has been written in recent years about the orthopaedist’s predilection for prescribing opioids, most of which has been aimed at helping us become better stewards of these medications. It is imperative that we continue learning how best to prescribe opioids to maximize their effectiveness in postoperative pain management, while minimizing their many harmful and potentially lethal effects. With some patients, finding that balance is much easier than with others. Learning to identify which patients may struggle with achieving that equilibrium is one way to address the current opioid epidemic.

In the September 18, 2019 issue of The Journal, Prentice et al. identify preoperative risk factors that are associated with prolonged opioid utilization after total hip arthroplasty (THA) by retrospectively evaluating the number of opioid prescriptions dispensed to >12,500 THA patients. Many of the findings are in line with those of previous studies looking at this question. Prentice et al. found that the following factors were associated with greater opioid use during the first postoperative year:

  • Preoperative opioid use
  • Female sex
  • Black race
  • Anxiety
  • Higher BMI
  • Substance abuse
  • Back pain
  • AIDS
  • Chronic pulmonary disease

For me, the most noteworthy finding was that almost 25% of all patients in the study were still using opioids 271 to 360 days after their operation. That is a much higher percentage than I would have guessed prior to reading this study. Somewhat less surprising but also concerning was the finding that 63% of these patients filled at least 1 opioid prescription in the year prior to their THA, leading the authors to suggest that orthopaedic surgeons “refrain from prescribing opioids preoperatively” or “decrease current opioid users’ preoperative doses.”

Although some readers may be suffering from “opioid fatigue” in the orthopaedic literature, I encourage our community to  continue addressing our role in the current opioid crisis. While I believe that we have changed our prescribing practices since the data for this study were collected (2008 through 2011), we cannot dismiss these findings. The opioid epidemic is multifactorial and has many deep-rooted tendrils in our healthcare system. We owe it to our patients and to the public at large to be as significant a part of the solution as possible.

Chad A. Krueger, MD
JBJS Deputy Editor for Social Media

Let’s Continue Improving Hip-Implant Longevity

In October 2017, JBJS published results from a 10-year randomized controlled trial by Devane et al. documenting the dramatic reduction in polyethylene wear in total hip arthroplasties (THAs) using highly cross-linked polyethylene (HXLPE). This followed decades of research documenting that wear debris was implicated in macrophage activity that was ultimately responsible for implant loosening. In the September 4, 2019 issue of The Journal, Hart and colleagues produce further evidence of the improved performance of HXLPE, this time showing revision rates among THA patients with osteonecrosis that rival the rates among patients with osteoarthritis.

In this matched cohort of 922 THAs performed from 1999 to 2007 that used an HXLPE bearing, the 15-year cumulative rate of revision was 6.6% among patients treated for osteonecrosis and 4.5% among patients treated for osteoarthritis (p = 0.09). There were no radiographic signs of component loosening in the entire cohort, and, despite a lower median preoperative Harris hip score (HHS) among patients with osteonecrosis, both groups had marked improvements in HHS score. These findings are especially noteworthy because patients with osteonecrosis typically undergo THA at an earlier age and have much higher functional demands than the typical 70- or 80-year-old osteoarthritis patient.

However, the 15-year revision rate—even with HXLPE—remains at 4.5% for osteoarthritis patients, which should provide impetus to continue our work identifying all possible factors and mechanisms that lead to THA revision. A partial list would include bearing-surface wear, reliability of implantation, biomechanics, biomaterials, and patient perception of postoperative pain. Also, in a subgroup analysis, Hart et al. found that the 15-year rate of any reoperation among osteonecrosis patients ranged from 0% for hips with radiation-induced osteonecrosis to 25% for hips with idiopathic osteonecrosis. These findings add to the list of factors for THA success that need further investigation.

The work list for improvements in THA will remain substantive for at least the next few decades, and we may never get to 0% revisions for all patients. But we have certainly demonstrated that our research can produce very worthwhile results.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Dual-Mobility Cups Lower Revision Risk in Some THAs

OrthoBuzz occasionally receives posts from guest bloggers. In response to a recent study in The Journal of Bone & Joint Surgerythe following commentary comes from Matthew Deren, MD.

Early or late dislocation after total hip arthroplasty (THA) is a dreaded complication, and performing a THA to treat a hip fracture is known to increase the risk of postoperative prosthetic joint dislocation. Large-diameter femoral heads, like those used in metal-on-metal implants, offered the prospect of decreased risk of dislocation. Unfortunately, their promise of improved stability was subsequently offset by serious issues with wear. Orthopaedics is notable for technology that promised to solve one problem but led to another, and some wonder whether the increasing popularity of THA using dual-mobility cups to reduce dislocation risk might lead to another example of this paradoxical problem.

However, in the July 17, 2019 issue of The Journal, Jobory et al. published a population-based prospective cohort analysis based on data from the Nordic Arthroplasty Register Association. That study demonstrated a reduced revision risk with dual-mobility acetabular components when THA was performed to treat hip fracture in elderly patients. The authors propensity-score matched 4,520 hip fractures treated with dual-mobility THA to 4,520 hip fractures treated with conventional THA. The study included surgeries from 2001 to 2014, and the median follow-up was 2.4 years for all patients.

Dual-mobility constructs had a lower overall risk of any-component revision (hazard ratio of 0.75), which persisted after authors adjusted for surgical approach (hazard ratio of 0.73). Additionally, the dual-mobility construct had a lower risk of revision due to dislocation (hazard ratio of 0.45), but there was no difference in risk of deep infection between the cohorts. There was no significant difference in risk of any-component revision for aseptic loosening (hazard ratio of 0.544, p=0.052) until the authors adjusted for approach, which resulted in a decreased risk of any-component revision for aseptic loosening (hazard ratio of 0.500, p=0.030). When the authors compared revision of the acetabular component only, they found a reduced risk of revision for any cause as well as revision for dislocation in the dual-mobility cohort using both unadjusted data and data adjusted for surgical approach. Mortality was higher in the dual-mobility group compared with the conventional-component group (hazard ratio of 1.5).

Overall, this study gives us more information regarding the short-term revision risks of an implant design that is gaining popularity in the US. Although dual-mobility constructs seem to be associated with a decreased risk of revision for dislocation in a population of older adults with hip fracture, this data tells us little about this design and technology when used in younger, more active patients, who are at higher risk of polyethylene wear.

Matthew Deren, MD is an orthopaedic surgeon at UMass Memorial Medical Center, an assistant professor at University of Massachusetts Medical School, and a member of the JBJS Social Media Advisory Board.

Good Outcomes and Savings with Preferred-Vendor Program

It has been said that outcomes of total joint arthroplasty are 90% related to surgeon factors (such as prosthetic alignment and fit and soft-tissue management), and only 10% to the implant itself. Historically, surgeon choices of implants for primary total hip and total knee arthroplasty have been based on influences such as the prostheses used during training, prior vendor relationships, specific patient characteristics, and findings in published literature. Absent evidence that the selection of prosthesis vendor affects patient outcomes to any significant degree, and with the universal focus on lowering health care costs, surgeon implant/vendor preferences have come under close scrutiny.

In the August 7, 2019 issue of The Journal, Boylan et al. study the impact of a voluntary preferred single-vendor program at a large, high-volume, urban orthopaedic hospital with >40 (mostly hospital-employed) arthroplasty surgeons. The hospital’s use of hip and knee arthroplasty implants from the preferred vendor rose from 50% to 69% during the program’s first year. In addition, the mean cost per case of cases in which implants from the preferred vendor were used were 23% lower than the mean cost-per-case numbers from the previous year (p<0.001). Boylan et al. noted that low-volume surgeons adopted the initiative at a higher rate than high-volume surgeons, and that surgeons were more compliant with using the preferred vendor for total knee implants than for total hip implants.

Why is it that some higher-volume surgeons seem resistant to change? It is not clear from the data presented in this study whether the answer is familiarity with an instrument system, loyalty to local representatives, or relationships with manufacturers based on financial or personal connections. The authors observed that “collaboration between surgeons and administrators” was a critical success factor in their program, and interestingly, the 3 highest-volume surgeons in this study (who performed an average of ≥20 qualifying cases per month) all used total knee implants from the preferred vendor prior to the initiation of this program.

The provocative findings from this and similar studies lead to many questions ripe for further research. Because hospitals are highly motivated to reduce implant costs in the bundled-payment environment, preferred-vendor programs are gathering steam. We need to better understand how they work (or don’t) for specific surgeons, within surgical departments, and within hospital/insurance systems in order to evaluate their effects on patient outcomes and maximize any cost benefits.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

What’s New in Musculoskeletal Infection 2019

Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.

This month, Thomas K. Fehring, MD, co-author of the July 17, 2019 What’s New in Musculoskeletal Infection,” selected the five most clinically compelling findings—all focused on periprosthetic joint infection (PJI)—from among the more than 90 noteworthy studies summarized in the article.

Preventive Irrigation Solutions
–An in vitro study by Campbell et al.1 found that the chlorine-based Dakin solution forms potentially toxic precipitates when mixed with hydrogen peroxide and chlorhexidine. The authors recommend that surgeons not mix irrigation solutions in wounds during surgery.

PJI Diagnosis
–A clinical evaluation by Stone et al. showed that alpha-defensin levels in combination with synovial C-reactive protein had high sensitivity for PJI diagnosis, but the alpha-defensin biomarker can lead to false-positive results in the presence of metallosis and false-negative results in the presence of low-virulence organisms.

–In an investigation of next-generation molecular sequencing for diagnosis of PJI in synovial fluid and tissue, Tarabichi et al. found that in 28 revision cases considered to be infected, cultures were positive in only 61%, while next-generation sequencing was positive in 89%. However, next-generation sequencing also identified microbes in 25% of aseptic revisions that had negative cultures and in 35% of primary total joint arthroplasties. Identification of pathogens in cases considered to be aseptic is concerning and requires further research.

Treating PJI
–A multicenter study found that irrigation and debridement with component retention to treat PJI after total knee arthroplasty had a failure rate of 57% at 4 years.2

–Findings from an 80-patient study by Ford et al.3 challenge the assumption that 2-stage exchanges are highly successful. Fourteen (17.5%) of the patients in the study never underwent reimplantation, 30% had a serious complication, and of the 66 patients with a successful reimplantation, only 73% remained infection-free. Additionally 11% of the patients required a spacer exchange for persistent infection.

References

  1. Campbell ST, Goodnough LH, Bennett CG, Giori NJ. Antiseptics commonly used in total joint arthroplasty interact and may form toxic products. J Arthroplasty.2018 Mar;33(3):844-6. Epub 2017 Nov 11.
  2. Urish KL, Bullock AG, Kreger AM, Shah NB, Jeong K, Rothenberger SD; Infected Implant Consortium. A multicenter study of irrigation and debridement in total knee arthroplasty periprosthetic joint infection: treatment failure is high. J Arthroplasty.2018 Apr;33(4):1154-9. Epub 2017 Nov 21.
  3. Ford AN, Holzmeister AM, Rees HW, Belich PD. Characterization of outcomes of 2-stage exchange arthroplasty in the treatment of prosthetic joint infections. J Arthroplasty.2018 Jul;33(7S):S224-7. Epub 2018 Feb 17.