ACL Grafts: Diameter Does Matter, Sort Of
Clinical failure of anterior cruciate ligament (ACL) reconstructions continues to be a too-common scenario. The increasing incidence of ACL revision is due to a variety of factors, including greater intensity of postsurgical physical activity, technical issues, and anatomical influences of the proximal tibia and distal femur. Registries are important sources of data for ACL-related investigations, but I think they are most useful in clarifying experimental designs for more sophisticated clinical research.
In a cohort study in the October 16, 2019 issue of The Journal, Snaebjornsson et al. examined the influence of ACL graft diameter on the risk of revision surgery over 2 years in >18,000 subjects whose data resided in the national knee ligament registries of Sweden and Norway. The vast majority of those patients (92.8%) received a hamstring autograft, with 7.2% receiving a patellar tendon autograft. Overall, the 2-year rate of ACL revision was 2.63% for patellar tendon autografts and 2.08% for hamstring autografts, a statistically nonsignificant difference in relative risk.
However, the authors found an important correlation between graft diameter in the hamstring tendon cohort, with autografts <8 mm in diameter being associated with a higher risk of revision, compared with larger-diameter hamstring autografts. Additionally, patients treated with hamstring graft diameters of ≥9 mm or ≥10 mm had a lower risk of ACL revision surgery than those treated with patellar tendon grafts of any size.
One key limitation that should influence our interpretation of this study is a lack of detail regarding how compliant surgeons were intraoperatively with the use of the measurement device that is depicted in the manuscript and shown above. In addition, the limitations of registry data did not permit the authors to adjust for postsurgical exposures, such as return to sport, the increasing intensity of which makes rerupture more likely. Additional relevant information that would have aided interpretation of the findings includes the relative size of the tibia and femur, lateral condyle size and shape, and proximal tibial slope.
Despite these limitations, this study should prompt further research that uses robust clinical designs to more fully investigate the impact of graft diameter on ACL rerupture rates.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Surgeon Volume Matters for TKA Alignment
The retrospective multicenter study of 1,570 primary total knee arthroplasties (TKAs) by Kazarian et al. in the October 2, 2019 issue of JBJS focused on evaluating the impact of surgeon volume and training status on implant alignment. But the most surprising (and concerning) finding was that even among high-volume attendings—the best-performing of the three surgeon cohorts studied—the proportion of TKA alignment “outliers” was still high.
The authors radiographically measured 3 postoperative TKA alignment parameters: medial distal femoral angle (DFA), medial proximal tibial angle (PTA), and posterior tibial slope angle (PSA). Using established thresholds for “outliers” and “far outliers” for those 3 measurements, the authors compared the radiographic findings among surgeries performed by high-volume attendings (≥50 TKAs/year), low-volume attendings (<50 TKAs/year), and trainees (supervised residents or fellows).
As has been shown in similar studies of total hip arthroplasty (THA), the group of high-volume attendings outperformed the low-volume attendings and the trainee group on nearly all measurements assessed in this study. Interestingly, in terms of TKA alignment, the low-volume attending group and the trainee group performed similarly.
Kazarian et al. express concern that “even the most accurate cohort in our study, [the high-volume attendings], placed only 69.0% of knees in optimal alignment for all 3 measurements.” While the authors admit that implant alignment is not a perfect proxy for clinical outcomes, they argue that “gross alignment outliers are likely to have an impact on knee function, kinematics, and wear characteristics.” Citing literature suggesting that the use of robotic-arm assistance may improve TKA alignment, the authors surmise that employing such technology to assist low-volume surgeons or trainees might optimize alignment and improve outcomes, despite the added up-front cost of the technology.
Surgery for Rotator Cuff Tears: The Better of Two Goods
We’re all familiar with the phrase “lesser of two evils,” but I’m an optimist and prefer the phrase “better of two goods.” In the October 2, 2019 issue of JBJS, Ramme et al. compare surgical versus nonsurgical treatment of full-thickness rotator cuff tears. Both cohorts had improved outcomes relative to baseline, but surgical management was the better of two goods.
The authors retrospectively analyzed a prospective cohort of adult patients with full-thickness rotator cuff tears who had elected either surgical or nonsurgical treatment. Ramme et al. utilized propensity score matching to pair up patients in each group according to factors thought to influence outcome, such as age, sex, tear size, chronicity, muscle atrophy, and the Functional Comorbidity Index. This matched-pair analysis is a valiant attempt to eliminate bias that is inherent in retrospective analyses, and this study design also mimics the real-world scenario of shared decision making between physician and patient.
The 2-year follow-up analysis of 107 propensity score-matched patients revealed that both groups improved in 4 patient-reported functional outcomes and pain compared to their baseline measures before treatment. However, the final outcome measurements and magnitude of improvement were statistically greater in the surgical management group (p <0.001).
This study will help shoulder surgeons have more meaningful discussions with their patients about treatment options for full-thickness rotator cuff tears. We know that with proper treatment—either surgical or nonsurgical—patients can expect improvement in pain and function. However, patients who elect surgical management may have the potential for even greater outcomes, and that definitely sounds like the “better of two goods.”
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Vancomycin Powder May Thwart Spinal Fusion
Prompted by relatively high infection rates associated with surgical treatment of pediatric spinal conditions such as scoliosis and spinal-deformity surgery in immunocompromised adults, spine surgeons have led “deep dive” clinical research into the possible benefits of local, intrawound antibiotic therapy. Consequently, the administration of antibiotic powder around the spine’s posterior elements and internal-fixation devices has become fairly widespread. But are there possible downsides to this approach that can impact patient outcomes?
This important question is addressed in the basic-science study by Ishida et al. in the October 2, 2019 issue of The Journal. The authors analyzed the fusion-specific impact of varying concentrations of intrawound vancomycin and tobramycin in a well-characterized rat model of posterolateral fusion performed with syngeneic iliac-crest allograft plus clinical bone-graft substitute. Ishida et al. found that a high dose of vancomycin (71.5 mg/kg, about 5 times higher than spine surgeons typically use) but not tobramycin had detrimental effects on fusion-mass formation in this model, as demonstrated by micro-computed tomography and histological analysis.
We now need further clinical research from the spine community to determine the optimal doses and types of intrawound antibiotics in this setting. Based on the currently available data, power calculations should be performed when designing future trials focused on this question. There seems to be little remaining doubt that locally delivered antibiotics help limit surgical-site and deep infections in spinal surgery. The impact of antibiotics on fusion rates must now be investigated further.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Expanded Indications for Medial UKA?
Along with recently renewed interest in unicompartmental knee arthroplasty (UKA) has come debate as to whether the preoperative presence of patellofemoral osteoarthritis (OA) and/or abnormal patellofemoral alignment should be considered UKA contraindications. Findings from a retrospective review of 639 knees by Burger et al. in the September 18, 2019 issue of The Journal of Bone & Joint Surgery strongly suggest that the answer is “no.”
After examining preoperative radiographic OA and alignment characteristics and postoperative patient-reported outcomes among patients who underwent fixed-bearing medial UKA, the authors concluded that “neither the [radiographic] presence of preoperative mild to moderate [patellofemoral] osteoarthritis nor abnormal patellar tilt or congruence compromised [patient-reported knee and patellofemoral-specific] outcomes at intermediate-term follow-up [mean of 4.3 ±1.6 years].”
Expanding the surgical inclusion criteria for UKA based on these findings could increase the number of patients eligible for UKA by 20% to 40%, estimated Burger et al. In the practice of the senior author (Andrew D. Pearle, MD), patients with symptoms of patellofemoral OA (such as anterior knee pain with prolonged sitting or stair-climbing) are considered ineligible for UKA, prompting the authors to suggest that “the presence of such symptoms may be better than radiographic criteria for determining which patients are eligible for medial [UKA].”
Seeking Trauma Section Head for JBJS Clinical Classroom
JBJS is currently seeking a Trauma Section Head for the JBJS Clinical Classroom learning system. Clinical Classroom is an interactive, adaptive learning tool featuring more than 3,500 questions and comprehensive responses across 10 orthopaedic specialties. Questions and responses are clinically relevant, peer reviewed, and authored by orthopaedic surgeons. The platform also provides substantive Learning Resources that enhance the user experience.
The Section Head is responsible for leading a team of authors and developing new trauma-related content on a yearly basis. In addition, the Section Head will address user challenges and feedback. Ideally, candidates should be fellowship trained, in orthopaedic practice for at least 5 years, and have a passion for clinical education.
Click here for more information on the Clinical Classroom product.
If you are interested in this opportunity, please contact Chris Chiodo, Editor, JBJS Clinical Classroom at cchiodo@jbjs.org. Please include your CV and a short statement describing your interest and experience in orthopaedic education.
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
Stop Adding Antibiotics to Irrigation Solutions
The rate of adoption of knowledge gleaned from multiple well-done randomized clinical trials into medical practice is disappointingly slow. This has been well-documented in cardiovascular medicine, and the examples in orthopaedic surgery are embarrassingly similar. A corollary phenomenon exists with the slow rate of transfer of information from basic science studies to orthopaedic clinical practice.
These “disconnects” occur largely because we tend to adopt the practices of our residency faculty, often without any rational inquiry. Having been an oral examiner for the Part II ABOS Oral Boards, I frequently asked, “Why did you decide on that approach to the patient’s problem?” And I often heard in response, “That’s the way it was done in my residency.”
In the September 18, 2019 issue of The Journal, Goswami et al,. report findings from a well-designed in vitro study demonstrating that the common practice of adding the antibiotics polymyxin and bacitracin to irrigation solution to lower the risk of infection is not based on sound evidence. While adding antibiotics might make intuitive sense, according to these authors, it is “a futile exercise.”
After testing 8 different irrigation solutions for efficacy against S. aureus and E. coli and for toxicity to musculoskeletal cells, Goswami et al. concluded that “our results provide further support for the use of dilute povidone-iodine because of its bactericidal properties, relatively limited toxicity,… and modest cost.” They go on to say that their findings bring into question the widespread usage of polymyxin-bacitracin.
Certainly, we need to assemble more evidence from additional research to identify the optimal irrigation solution for orthopaedic surgery, but in the interim, we should probably stop using polymyxin-bacitracin. Doing so would have the added benefits of lowering costs and not exacerbating the serious problem of antimicrobial resistance. There are many areas of clinical practice where we have no evidence either for against a particular approach. But when we do have solid evidence, even if it’s from an in vitro study, we should work together to improve the rates of adoption into clinical practice.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
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!
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