Chicago Orthopaedic Surgery PGY1 Journal Club Commentary

I was pleasantly surprised and excited when I first heard about the citywide Chicago PGY1 journal club. This journal club was funded by the Robert Bucholz Resident Journal Club Grant through The Journal of Bone and Joint Surgery. The premise of this program was for all of the orthopedic surgery PGY1s from around the city to meet and discuss landmark articles specific to a certain orthopedic topic. The event that I attended was the first meeting of the program, and the focus of our discussion revolved around four orthopedic trauma articles. I recognized all of the articles as the guidelines established from these papers are still used in our trauma practice every day.

Although I knew the general principles derived from this literature, I found reading the full text beneficial as it helped provide a more thorough background into the reasoning behind the decisions we make in the management of various fracture patterns. What I found most educational however was the discussions we had with residents at various programs, specifically in regards to our institutions’ management of common orthopedic fractures. We each went around the table and discussed our ED management of injuries including humeral shaft fractures, femoral shaft fractures, open fractures, and our intraoperative technique for intramedullary nailing of tibial shaft fractures.

While there were small differences in our management of these injuries, we all seemed to abide by the general guidelines that were set into motion after the publication of these landmark articles. It brought into focus how influential this literature has been, and also gave me additional insight into possible alternative management algorithms that could produce similar outcomes. When working at one institution throughout your residency, that institutions protocols often become the “normal” for you. I now better recognize that it is important to keep an open mind and that there can be many methods to achieve a desired result.

Our meeting allowed for a low stress environment to both appreciate and constructively criticize how we think about orthopedic trauma. At our specific institution the discussion of articles occurs in a large group setting with attendings and senior residents, and usually focuses on more recent literature. I think it is essential to understand where we came from, and this citywide journal club provides that history while also encouraging open critical discussion. I think any junior resident would benefit from this type of educational open forum with their colleagues.

You can apply for your own Robert Bucholz Resident Journal Club Grant by clicking this link.

Jeremy Adler

Orthopaedic Surgery, PGY-2

University of Chicago

Jeremy.adler@uchospitals.edu

Elite Reviewer Spotlight: Antonia Chen

In celebration of Peer Review Week, JBJS is pleased to present the first in a series of profiles highlighting our Elite Reviewers. The Elite Reviewers Program recognizes our best reviewers for their outstanding efforts. All JBJS reviewers help us maintain the highest standards for quality orthopaedic publishing.

Name: Antonia F. Chen, MD, MBA

Affiliation: Brigham and Women’s Hospital / Harvard Medical School, Boston, MA

Years in practice: 5

How did you begin reviewing for other journals and for JBJS in particular?

As a resident, one of my attendings asked me to review for a different journal given my interest in research.   The guidelines for reviewers were incredibly helpful, and I initially spent days reviewing a study trying to critically analyze it and provide constructive feedback. Subsequently, I met Dr. Tom Bauer at a meeting, and given my research interests, he invited me to review an article for JBJS. It’s been an incredible privilege to review for JBJS, and the critical thinking skills developed as a reviewer have helped me become a better writer.

What is your top piece of advice for those reviewers who aspire to reach Elite status?

The more you practice reviewing, the more intuitive it becomes; try to do as many reviews as possible. I like to read an article twice – once to get the general gestalt of an article to understand if/how everything ties together, then a second time to critically analyze the article and try to find loopholes in the article. By doing so, I am able to understand the big picture before getting into the details of a manuscript.

Aside from orthopaedic manuscripts, what have you been reading lately?

I recently read The Life Changing Magic of Tidying Up. I have so many changes to make!

Learn more about the JBJS Elite Reviewers program.

Mehta Casting for Early-Onset Scoliosis: Predictors of Success

The treatment of early-onset scoliosis with Mehta casting is a long process, but if successful, it can delay or obviate the need for surgery. In the September 4, 2019 issue of JBJS, Fedorak et al. examine outcomes among 38 patients (mean age of 24 ± 15 months at time of first casting) who were treated with Mehta casting and followed for a mean of 8 ± 2 years. The retrospective review identified differences between patients who had a Cobb angle ≤15° (improvement group) at the most recent follow-up and those who had a Cobb angle of >15° (no-improvement group).

Forty-nine percent of children had achieved and maintained scoliosis of ≤15° at the time of the most recent follow-up, and 73% were improved by at least 20°, although 3 children ended up relapsing after meeting recommended criteria for discontinuation of casting. There was no significant difference in thoracic-height gain between the groups, demonstrating that even when scoliosis was not corrected, growth was maintained during cast treatment.

Patients in the improvement group had a mean age of 18.9 ± 12 months and scoliosis of 48.2° ± 14° at the initiation of treatment. Here are 3 additional factors that were associated with a greater likelihood of scoliosis of ≤15°:

  • A lower pre-treatment Cobb angle and traction Cobb angle
  • A smaller rib-vertebral angle difference on first-in-cast radiograph
  • A lower Cobb angle on first-in-cast radiograph

The authors note that although this study analyzed longer-term follow-up data than most other similar investigations, “treatment of early-onset scoliosis is not truly finished until skeletal maturity has been reached.”

Patient Discharge after Knee Replacement: How Soon Is Safe?

For most patients and payers, getting out of the hospital quickly after a knee replacement is very important. For orthopaedic surgeons, excellent patient outcomes are the top priority. The latest one-hour complimentary webinar from JBJS on Tuesday, October 1, 2019 at 8:00 pm EDT will reveal clinical practices that increase the odds of achieving both of those goals.

Co-authors Nelson SooHoo, MD and Armin Arshi, MD will explore data from their JBJS study comparing complication rates after outpatient and inpatient knee-replacement, emphasizing that outpatients must receive the same attention to infection prevention, thromboprophylaxis, and rehabilitation as inpatients.

Kurt Spindler, MD and Robert Molloy, MD will then delve into their JBJS study, which suggests that hospital site, surgeon, and day of the week are more accurate predictors of length of hospital stay after knee replacement than patient age, BMI, and comorbidities.

Moderated by Daniel Berry, MD of the Mayo Clinic, the webinar will also feature expert commentaries by Joseph Moskal, MD and Ronald Delanois, MD. The webinar will conclude with a 15-minute live Q&A session during which attendees can ask questions of all the panelists.

Seats are limited, so Register Now!

Plate–Tendon Contact: How Important Is It?

There are few things more discouraging for an orthopaedic surgeon than a late postoperative complication after what was an otherwise successful surgery. One such scenario occurs when patients who have undergone open reduction/internal fixation (ORIF) for a distal radial fracture subsequently experience a flexor pollicis longus (FPL) tendon rupture. While previous literature has suggested that plate positioning plays a role in that complication, no studies have evaluated whether newer plate designs decrease contact with the FPL tendon and therefore reduce the risk of rupture.

With that question in mind, Stepan et al. evaluated two cohorts of patients who had undergone ORIF for a distal radial fracture. In the September 4, 2019 issue of JBJS, they report on findings from 40 patients, 20 of whom received a standard distal radial volar locking plate, and 20 of whom received a plate designed with a distal cutout to afford the FPL more room to traverse.

Ultrasound analysis revealed that similar percentages of patients in each group had FPL–plate contact (65% in the FPL-plate group and 79% in the standard-plate group), and there were no differences between groups in terms of FPL tendon degeneration as seen on ultrasound. However, patients who received the FPL plate had significantly less of the tendon come in contact with the plate at 0° and 45° of wrist extension. The authors noted, however, that this difference may have been influenced by the fact that patients with the FPL-specific plate also had significantly lower volar tilt than patients with the standard locking plate. It is therefore not possible to determine whether it was the plate design or the bone position (or both) that led to these results.

It is also noteworthy that the two senior authors of this study work as consultants for the company that manufactures the plates that were evaluated. It is also important to note that because all the patients in this study were asymptomatic, further research is needed to determine the clinical importance of reduced tendon–plate contact area. We should temper our excitement about specially designed volar plates until we have more clinical data supporting their success in avoiding the problem for which they were designed.

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

Not Your Grandparent’s Journal Club

OrthoBuzz occasionally receives posts from guest bloggers. The following commentary comes from Matthew R. Schmitz, MD, FAOA.

Medical education is a constant need, but how it’s delivered is always changing. When my grandfather was a surgeon, medical trainees brought their dusty textbooks and print journals to “fireside chats” at an attending’s home. Today, we have online journals, tablets and smartphones, podcasts, and “virtual” discussions on social media platforms. Although the technologies evolve, the need to discuss present and past literature remains constant.

These discussions often taken place nowadays through journal clubs. Medical residents across the continent routinely get together in formal or informal settings to discuss journal articles, not only to acquire the knowledge contained in the articles themselves, but also to learn how to properly read, critique, and digest the information.

JBJS provides medical education across multiple platforms, several of which I participate in. I strongly encourage residency programs to submit an application for the 2019-2020 JBJS Robert Bucholz Resident Journal Club Grant Program before the deadline of September 30, 2019. The grant allows medical educators to support their journal clubs in many ways:

  • Investigating new and innovative alternatives to the traditional journal club.
  • Bringing an author to your institution to discuss his or her articles.
  • Hosting a virtual journal club with multiple authors via teleconference or social media.
  • Purchasing food and refreshments within the “old school” method of a fireside chat at an attending’s home.

No matter the platform or methodology, journal clubs are a vital part of orthopaedic education, not only for interpreting literature, but also for incorporating knowledge into future clinical practice and for the joy and excitement of lifelong learning.

Matthew R. Schmitz, MD, FAOA is an orthopaedic surgeon specializing in adolescent sports and young adult hip preservation at the San Antonio Military Medical Center in San Antonio, TX. He is also a member of the JBJS Social Media Advisory Board.

Who Doesn’t Have a Screw Loose?

This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.

Fracture fixation with a plate and screws has been around for a century—and so has the problem of screw loosening. Part of the cause of screw loosening seems to be toggling caused by radial forces arising from plate micromotion. Several decades ago, locked screws were designed to prevent loosening and provide better fixation, but screws still loosen.

Two tests can predict screw loosening associated with bone microfracture and absorption: axial pullout stress and toggling radial stress. Recent studies have investigated two hypotheses: radial stress is a predominant cause of screw loosening, and bone resorption is triggered by high radial stress.

Finite Element Analyses

A finite elemental model was used to replicate fixation of a tibial fracture with a 3-mm gap using either a dynamic compression plate (DCP) or locking compression plate (LCP).1 The model included contact with bone, tension on screw insertion, and the placement of two inner screws and one outer screw on either side of the fracture for an 8-hole plate. Axial loading, torsional loading, and bending were applied. Forces exceeding 55 megapascal (MPa) were considered adequate to cause microfracture, whether by radial or axial force. (For reference, 55 MPa is just about 8,000 pounds per square inch.)

The principal finding was that more bone was damaged by radial than by axial stress in both types of plates. Both plate types had more bone damaged by radial stress at the central two screws than at the two end screws for all bending models.

Radiographic Analyses

A separate study evaluated clinical radiographs of fixation for humeral, radial, ulnar, femoral, and tibial shaft fractures. Researchers looked for screw migration or bone absorption of  ≥1 mm around the screw. Both DCPs and LCPs were reviewed.

Researchers found that the outer screws loosened only after the inner screws loosened. There were 3 cases of bone loss with no loosening, 17 cases of bone loss with screw displacement, and no cases of screw loosening without bone loss. This strongly suggests that bone loss must occur for loosening to take place and that the earliest screw loosening occurs closer to the facture site.

Taken together, these results imply that the use of larger inner screws and/or the use of a different angle of fixation might reduce bone absorption that leads to loosening. In addition, radial stress testing might be more important than axial testing. Still, LCPs remain superior at resisting axial loading and bending moments, while DCPs remain superior at resisting torsional loading of unstable fractures.

Reference

  1. Feng X, Lin G, Fang CX, Lu WW, Chen B, Leung FKL. Bone resorption triggered by high radial stress: The mechanism of screw loosening in plate fixation of long bone fractures. J Orthop Res. 2019 Jul;37(7):1498-1507. doi: 10.1002/jor.24286. Epub 2019 Apr 8 PMID: 30908687

What’s New in Limb Lengthening and Deformity Correction 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, Mark T. Dahl, MD, co-author of the August 21, 2019 What’s New in Limb Lengthening and Deformity Correction,” selected the five most clinically compelling findings from among the 40 noteworthy studies summarized in the article.

Congenital Pseudarthrosis
–Authors of a retrospective study of 119 patients with Crawford type-II congenital pseudarthrosis of the tibia found a 69% union rate at maturity. They did not identify specific factors influencing rates of union or refracture, however.1

3-Dimensional Printing
–The models created with this technology can help surgeons preoperatively assess specific anatomical geometries. Corona et al.2 used 3-D-printed titanium truss cages, along with the Masquelet technique, to treat massive infected posttraumatic defects.

Growth Prediction in Limb Lengthening
–A comparative evaluation of the predictive accuracy of 4 methods to correctly time epiphysiodesis in 77 patients found the multiplier method to be the least accurate. In a separate study of 863 epiphysiodeses, authors reported a 7% complication rate.3 The most common complication was incomplete arrest that resulted in angular deformities; half of those cases required reoperation.

Congenital Limb Deficiencies
–Over 16 years, Finnish children born with lower-limb deficiencies had 6 times the number of hospital admissions and 10 times the number of days in hospital per child, compared with children born without a limb deficiency.4

References

  1. Shah H, Joseph B, Nair BVS, Kotian DB, Choi IH, Richards BS, Johnston C, Madhuri V, Dobbs MB, Dahl M. What factors influence union and refracture of congenital pseudarthrosis of the tibia? A multicenter long-term study. J Pediatr Orthop. 2018 Jul;38(6):e332-7.
  2. Corona PS, Vicente M, Tetsworth K, Glatt V. Preliminary results using patient-specific 3D printed models to improve preoperative planning for correction of post-traumatic tibial deformities with circular frames. Injury. 2018 Sep;49(Suppl 2):S51-9.
  3. Makarov MR, Dunn SH, Singer DE, Rathjen KE, Ramo BA, Chukwunyerenwa CK, Birch JG. Complications associated with epiphysiodesis for management of leg length discrepancy. J Pediatr Orthop. 2018 Aug;38(7):370-4.
  4. Syvänen J, Helenius I, Koskimies-Virta E, Ritvanen A, Hurme S, Nietosvaara Y. Hospital admissions and surgical treatment of children with lower-limb deficiency in Finland. Scand J Surg. 2018 Nov 19:1457496918812233. [Epub ahead of print]

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.