Archive | March 2021

Proximal Humeral Fractures: More Data on Nonunion Risk

Proximal humeral fractures tend to occur in a bimodal distribution, namely, in younger, primarily male patients and in older (>65 years of age), primarily female patients. In the latter population, such fractures are often related to low bone density, and we in the orthopaedic community now recognize the imperative to evaluate at-risk individuals through measures such as DXA scanning and laboratory assessments of bone health in order to institute appropriate monitoring and pharmacotherapy.

Regarding the treatment of these fractures, several large trials have demonstrated that, for select fracture patterns, nonsurgical care results in clinical and functional outcomes that are equal to or better than surgical care with open reduction and internal fixation or arthroplasty. The question for treating clinicians is: are there proximal humeral fracture patterns that have higher rates of complications (chiefly nonunion) following nonsurgical care?

In a retrospective study reported in JBJS, Goudie and Robinson evaluated the rate of nonunion among patients who were treated nonoperatively for a proximal humeral fracture at their regional trauma center in the UK. They also sought to develop and validate a prediction model to assess nonunion risk, measuring the effect of 19 patient demographic and radiographic variables on healing.

Overall, 231 (10.4%) of the 2,230 included patients experienced nonunion. Among those with valgus angulation of the humeral head (395 patients), the nonunion prevalence was <1%, and none of the other variables evaluated were associated with increased risk of nonunion in a multivariable analysis. However, among the 1,835 patients with neutral or varus angulation of the head, the prevalence of nonunion was 12.4%, and decreasing head-shaft angle, increasing head-shaft translation, and smoking were independently predictive of nonunion.

Important to note is the residual pain and diminished function that often accompanies nonunion. Still, the authors rightly point out that “surgery aimed solely at preventing nonunion exposes patients to the risk of other complications that are not encountered with nonoperative treatment.” But, based on these findings about fracture morphology, they conclude that “medically fit patients with translated and/or angulated fractures should be counseled about smoking cessation and considered for surgery to avoid the debilitating effects of subsequent nonunion.” Patients with these fracture characteristics deserve closer scrutiny in our efforts to provide the best treatment for proximal humeral fractures.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Click here for a JBJS Clinical Summary on proximal humeral fractures.

Trimming the Fat (Pad) in Knee OA

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. It has been sent to >3,000 members of the Orthopaedic Research Society (ORS). For more information about the ORS, visit http://www.ors.org

The knee joint is comprised of cartilage, fibrocartilage, bone, synovium, ligaments, a fibrous capsule, and adipose tissue, the last of which includes the large anterior infrapatellar fat pad (IFP). The role of synovial inflammatory cells and cytokines in knee osteoarthritis (OA) has been well studied. The IFP is also rich in stem cells and inflammatory cells. Because Hartley guinea pigs naturally develop a form of knee OA that is similar to human disease, researchers recently used them as a model for elucidating a possible role of the IFP in knee OA.1

Ten 3-month-old guinea pigs had a unilateral IFP excision from one knee, with sham surgery performed on the opposite knee. Hartley guinea pigs typically develop OA after three months, and this intervention sought to determine whether IFP excision protected against OA. Gait analysis data were collected prior to surgery and then monthly until the animals were harvested at 7 months of age, at which point researchers performed microcomputed tomography (microCT) and histopathology on all 20 knee joints.

In knees with IFP resection, fibrous connective tissue replaced the adipose tissue. Stride length was not statistically different for either hindlimb throughout the study. Joints with resected IFPs had a decreased microCT score compared to contralateral intact knees (p <0.0001), indicating healthier cartilage. Histopathologically, the mean modified Mankin score of knees with IFPs removed was 2.556 versus 12.56 in contralateral knees (p <0.0004).

Surgeons commonly resect the fat pad during reconstructive knee surgery in humans, with no known reports of adverse effects beyond decreased range of motion due to local fibrosis. A recent review of the contribution of the IFP and synovium to knee OA pain2 suggests that synovial tissue and adipose tissue may act as a “functional unit” and have a combined effect on OA pathogenesis and, in all probability, OA pain and progression.

References

  1. Afzali MF, Radakovich LB, Pixler ZC, Campbell MA, Sanford JL, Marolf AJ, Donahue T, Santangelo, Kelly S. Early removal of the infrapatellar fat pad beneficially alters the pathogenesis of primary osteoarthritis in the Hartley guinea pig ORS 2020 Annual Meeting Paper No.0166
  2. Belluzzi E, Stocco E, Pozzuoli A, Granzotto M, Porzionato A, Vettor R, De Caro R, Ruggieri P, Ramonda R, Rossato M, Favero M, Macchi V. Contribution of Infrapatellar Fat Pad and Synovial Membrane to Knee Osteoarthritis Pain. Biomed Res Int. 2019 Mar 31;2019:6390182. doi: 10.1155/2019/6390182. eCollection 2019.PMID: 31049352

Outpatient Knee/Hip Arthroplasty Yields Fewer Adverse Events

The National Surgical Quality Improvement Program (NSQIP) database contains more than a half-million records of patients who received a total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), or total hip arthroplasty (THA) from 2009 through 2018. Fewer than 4% of those procedures were done in an outpatient setting, but patient demand for outpatient arthroplasty is rising rapidly.

With retrospective data like that from NSQIP, the most meaningful comparisons between inpatient and outpatient procedures come through a propensity score-matched analysis. Propensity score matching pairs up patients in each group according to multiple factors thought to influence outcome. In a recent study in The Journal of Bone & Joint Surgery, Lan et al. used propensity score matching to compare inpatient and outpatient arthroplasty in terms of adverse events and readmissions.

What the Researchers Did:

  • Matched each outpatient case of TKA, UKA, and THA from the database with 4 unique inpatient cases based on age, sex, ASA class, race, BMI, type of anesthesia, and history of hypertension, smoking, congestive heart failure, and diabetes
  • Compared inpatient vs outpatient rates of 30-day adverse events (both minor and severe) and readmissions
  • Identified risk factors for adverse events and readmissions

What the Researchers Found:

  • For all 3 arthroplasty types, patients who underwent an outpatient procedure were less likely to experience any adverse event, when compared with those who underwent an inpatient procedure.
  • The above adverse-event findings held true when TKAs, UKAs, and THAs were analyzed separately.
  • Outpatient procedure status was an independent protective factor against the risk of adverse events.
  • For all 3 procedures, readmission rates were similar among inpatients and outpatients. (The 2 most common reasons for readmission were infections and thromboembolic events.)
  • Clinicians are probably (and reasonably) selecting healthier patients to undergo outpatient procedures, but 42% of the outpatient cohort had an ASA class ≥3, and 55% had a BMI ≥30 kg/m2.

In their abstract, the authors cited “increased case throughput” as one rationale for outpatient arthroplasty, but this study provides convincing evidence that adverse-event reduction is another compelling reason for certain patients to consider outpatient knee and hip procedures.

Machine Learning Algorithm May Predict Postfracture Infection

Infection after surgery to treat a tibial shaft fracture can have devastating consequences, with significant associated costs and burdens. Although research has identified general risk factors that increase the likelihood of infection (including complexity of injury and fracture patterns and patient-related factors such as smoking and diabetes), predicting risks for individual patients remains difficult.

In a recent study in The Journal, investigators from the Machine Learning Consortium reported on an algorithm they developed to predict the risk of  infection in specific patients who receive operative treatment for a tibial shaft fracture. To develop their model, the researchers used high-quality data from the SPRINT (Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures) and FLOW (Fluid Lavage of Open Wounds) randomized controlled trials.

The Australian researchers “trained” 5 machine learning algorithms and tested them against various performance measures to evaluate 1,822 fractures, including 170 (9%) that developed an infection. Based on predictive performance in that derivation portion of the study, 3 algorithms were validated and 1 prediction model was found to be superior. In that model, Gustilo-Anderson Type IIIA and IIIB fractures, age, AO/OTA type 42C3 fractures, crush injuries, and falls were the strongest predictors of infection.

Researchers have made their model available in an online, open-access prediction tool. Although the authors emphasize that this preliminary tool is intended for research and not for widespread clinical use, I think it has profoundly positive potential. Being able to risk-stratify a patient with a tibial shaft fracture at or near the time of admission could allow surgeons to closely monitor—and intervene sooner—in fracture cases at risk for infection, thereby possibly preventing devastating complications. This prediction tool certainly needs external validation prior to “prime-time” adoption, but when it comes to exploring artificial intelligence and machine learning in orthopaedics, the future is now.

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

What’s New in Hand and Wrist Surgery 2021

Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 14 specialty areas. Click here for a collection of all such OrthoBuzz Guest Editorial summaries.

This month, author Christopher J. Dy, MD, MPH summarizes the 5 most compelling findings from the 40 studies highlighted in the most recent What’s New in Hand and Wrist Surgery.”

Carpal Tunnel Syndrome

–Corticosteroid injection is one modality for managing carpal tunnel syndrome, and a recent study examined the accuracy of needle placement1. Of 756 simulated injections, correct placement was noted for 572 (76%). The needle was placed in the median nerve 66 times (8.7%), and the carpal tunnel was missed 118 times (15.6%). As noted by the study authors, “safety of carpal tunnel injection remains an important concern.”

Cubital Tunnel Syndrome

–One recent study evaluating patient-reported outcomes of in situ decompression for cubital tunnel syndrome found that 66 (86%) of 77 patients were satisfied2. All of the patients who were not satisfied had preoperative weakness of the muscles innervated by the ulnar nerve.

Distal Radial Fracture

–A retrospective radiographic analysis of 273 uninjured adult distal radii found that the volar cortical angle (VCA) ranged from 23° to 43° (mean, 32°)3. With most volar locking plates having a fixed angle of 18° to 30°, there is a strong possibility of a mismatch between the patient’s VCA and the implant. If the patient’s VCA exceeds the implant’s fixed angle, undercorrection of sagittal tilt may result if the plate is used to guide reduction in treating a distal radial fracture.

Dupuytren Contracture

–A recent report presented a single surgeon’s experience over an 11-year time frame with 3 common treatments of Dupuytren contracture4. The rates of reintervention after needle aponeurotomy were 24% at 2 years and 61% at 5 years; after collagenase injection at the same time points, 41% and 55%; and after surgical fasciectomy, 4% at both 2 and 5 years. When factoring in cost, needle aponeurotomy appeared to be a high-value intervention.

Scapholunate Dissociation

–Among 203 patients who underwent  3-ligament tenodesis for scapholunate injury, improvement in patient-reported outcomes at 1 year was noted for 79%, but 10% had no change, and 11% had worse patient-reported outcomes5. Indications for 3-ligament tenodesis may need further clarification.

References

  1. Green DP, MacKay BJ, Seiler SJ, Fry MT. Accuracy of carpal tunnel injection: a prospective evaluation of 756 patients. Hand (N Y). 2020 Jan;15(1):54-8. Epub 2018 Jul 13.
  2. Yeoman TFM, Stirling PHC, Lowdon A, Jenkins PJ, McEachan JE. Patient-reported outcomes after in situ cubital tunnel decompression: a report in 77 patients. J Hand Surg EurVol. Vol 2020 Jan;45(1):51-5. Epub 2019 Oct 30.
  3. Gandhi RA, Hesketh PJ, Bannister ER, Sebro R, Mehta S. Age-related variations in volar cortical angle of the distal radius. Hand (N Y). 2020 Jul;15(4):573-7. Epub 2018 Dec 31.
  4. Leafblad ND, Wagner E, Wanderman NR, Anderson GR, Visscher SL, Maradit Kremers H, Larson DR, Rizzo M. Outcomes and direct costs of needle aponeurotomy, collagenase injection, and fasciectomy in the treatment of Dupuytren contracture. J Hand Surg Am. 2019 Nov;44(11):919-27. Epub 2019 Sep 17.
  5. Blackburn J, van der Oest MJW, Poelstra R, Selles RW, Chen NC, Feitz R; Hand-Wrist Study Group. Three-ligament tenodesis for chronic scapholunate injuries: short-term outcomes in 203 patients. J Hand Surg EurVol. Vol 2020 May;45(4):383-8. Epub 2019 Nov 11.

 

Outcomes of Joint-Preserving Surgery in RA-Affected Feet

Dramatic improvements in medical treatment of rheumatoid arthritis (RA) have led to marked reductions in joint damage and deformities. Consequently, surgical methods for treating RA-related foot problems have gradually evolved from joint-sacrificing to joint-preserving procedures. In a recent issue of The Journal of Bone & Joint Surgery, Yano et al. reported on outcomes of 105 feet in RA patients treated with joint-preserving methods followed up for a mean of 6 years.

What the Researchers Did:

  • Performed a proximal rotational closing-wedge osteotomy of the first metatarsal and modified shortening oblique osteotomies of the lesser metatarsals
  • Recorded Self-Administered Foot Evaluation Questionnaire (SAFE-Q) scores preoperatively and at latest follow-up
  • Measured hallux valgus angle (HVA), intermetatarsal angle (IMA), and medial sesamoid position before surgery, 3 months after surgery, and at the latest follow-up
  • Tracked delayed wound healing, hallux valgus recurrence, nonunion, and reoperations
  • Calculated Kaplan-Meier survivorship with reoperation as the endpoint

What the Researchers Found:

  • Surgery was associated with significantly improved median SAFE-Q scores, relative to preoperative values.
  • The average HVA, IMA, and grade of medial sesamoid positioning decreased significantly, compared with preoperative measurements.
  • Kaplan-Meier survivorship at 7 years was 89.5%.
  • Delayed wound healing was found in 20% of the feet (all wounds healed with nonoperative treatment), hallux valgus recurrence in 10.5% of the feet, and reoperation in 10.5% of the feet.

Yano et al. emphasize several advantages of joint-sparing over joint-sacrificing surgery: preserved range of motion, stability of the metatarsophalangeal joint, and improved plantar-pressure distribution. However, these advantages and the “satisfactory” long-term outcomes noted above come with substantial complications that foot-and-ankle surgeons will strive to address in the future.

Long-Term Patient Follow-up: Not Easy but Worth the Effort

Longer-term follow-up of orthopaedic patients is instrumental to research and the advancement of patient care. One simply cannot understand the impact of surgical decision-making and technique without examining the patient, assessing images, and evaluating function over time. However, in all areas of orthopaedic surgery, we struggle to get patients to return for evaluation when they feel mostly recovered. If patients are doing well in terms of pain and function, they may understandably see little or no clinical imperative to return for follow-up. This is particularly true among younger, more active patients—the primary group involved in higher-energy trauma and those who are perhaps the most resistant to follow-up visits.

Conversely, the orthopaedic research community and the journals that publish their findings have a widely embraced expectation of 1-year minimum follow-up. Agel et al. closely scrutinize this expectation/reality disconnect in a recent JBJS report. Reviewing 293 patients treated surgically for acute orthopaedic trauma injuries (mean age, 47.5 years), the authors observed a 29% rate of 1-year follow-up. Evaluating potential risk factors for patients not following up, they identified tobacco use, final appointment status (follow-up as needed vs request to return), isolated vs. multiple fractures, and distance from the trauma center as significant predictors.

While the authors ultimately concluded that a 1-year follow-up requirement “may not be feasible,” I think treating physicians can play a critical role in improving follow-up, even in trauma cases, where a physician-patient relationship may not exist prior to treatment. In addition to cementing a relationship with all our patients, we should clearly articulate that returning for evaluation will help subsequent patients with similar injuries or conditions.

In their “Author Insights” video about this study, co-authors Conor P. Kleweno, MD and Avrey A. Novak, MD cite new technologies for contacting patients for follow-up evaluations. I believe that, given convenient opportunities to do so, many patients will want to help us improve care for those who come after them.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Mouse Paws Good for Investigating Pyogenic Flexor Tenosynovitis

Although an infected finger may not sound like a big deal, the closed-space bacterial infection known as pyogenic flexor tenosynovitis (PFT) has been described as “one of the most devastating infections in the upper extremity.” PFT can rapidly spread from one digit to another, and the incidence of posttreatment complications—including adhesions and tendon tears—has been reported to be as high as 38%.

In a recent issue of JBJS, Qiu et al. report on a mouse model that could help us better understand the pathophysiology of PFT—and more efficiently test established and novel ways of treating it. Previous basic-science investigations into PFT have relied on avian models, but those have proven to be expensive and hard to scale and maintain.

What the Researchers Did:

  • Inoculated the tendon sheath of 36 male mouse hind-paws with bioluminescent forms of either Staphylococcus aureus or sterile saline
  • Monitored the infected and control cohorts for bioluminescence values and clinical signs such as digit swelling and body-weight reduction
  • Performed histological analysis of control and infected paws

What the Researchers Found:

  • A significant increase in bioluminescence in the infected group for the first 2 days after infection
  • Significantly lower weights in the infected animals compared with controls
  • Swelling, scar formation, collapse of the intrasheath space, and thickening of the tendon sheath itself in the infected group

Qiu et al. say this mouse model “could serve as a platform in further understanding the pathophysiology of PFT” and could help evaluate therapies aimed at reducing scarring and stiffness.

Click here to read the JBJS Clinical Summary on Infections of the Hand by Ryan Calfee, MD.

Strengthening Our Residency Programs through Robust Research

Residency training is an essential pipeline to keeping the field of orthopaedics strong. As I tell the surgeons in my department, we should always be looking for our replacement. Who is going to carry the flag of orthopaedics after our time has passed?

Research related to education and training helps guide us. Continuing a collaboration between the American Orthopaedic Association’s (AOA) Council of Orthopaedic Residency Directors (CORD) and JBJS, the top abstracts from research presented at the 2019 CORD Summer Conference are now available in an article by Weistroffer and Patt on behalf of the CORD/Academics Committee.

Ten studies are featured, with a number looking at aspects of resident screening and selection. For instance, Pacana et al. evaluated use of the standardized letter of recommendation (SLOR) form; while widely adopted, it may not be a cure-all in evaluating applicants, as most applicants were “highly ranked” or “ranked to match.” Work by Secrist et al. suggests that 59 is the number of programs that medical students should target in order to obtain 12 residency interviews (with previous work showing that the average matched applicant attends 11.5 interviews). Alpha Omega Alpha status was the strongest determinant of an applicant’s interview yield. Crawford et al. surveyed residency applicants to find out which characteristics they felt were important to success in an orthopaedic residency. Hard work, compassion, and honesty made the top-10 list each year.

The importance of diversity within orthopaedics is also echoed in the included research. It is well documented that orthopaedic surgery falls far behind other specialties in this area. Among topics explored: potential differences in descriptive terms used in letters of recommendation for male and female candidates, and perceptions of pregnancy and parenthood during residency. Illustrating the importance of exposure and access to role models in orthopaedics, Samora and Cannada found that 80% of female medical students who received a scholarship to attend the Ruth Jackson Orthopaedic Society/AAOS annual meeting eventually pursued a career in orthopaedic surgery. I agree with the authors, who stated, “We must work on diversifying our field and providing opportunities for women and underrepresented minorities to consider a career in orthopaedics.”

I know we will continue to make positive change as a profession. Moreover, I am convinced that the future of orthopaedics is strong, with many with top-notch candidates ready and able to help shape our path.

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