Archive | May 2019

Meniscal Extrusions: Imaging and Repair

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.

Loss of hoop stress by either medial or lateral menisci can cause meniscal extrusion, which results in increased forces on articular cartilage. The degree of meniscal extrusion is typically measured as a 2-dimensional distance with MRI. However, investigators recently used 3-D MRI to analyze the relationship between medial meniscal extrusion (MME) and femoral cartilage change in patients with these tears.1

Fifteen males (mean age of 56 years) with a medial meniscal degenerative tear (grade 3 by the Mink classification) based on MRI were included. The cartilage area was reconstructed in 3-D, and the femoral cartilage was projected in 2-D by 3-D MRI analysis. The femoral cartilage of the femorotibial joint was divided into 4 segments, and the cartilage area ratio was defined as the ratio of cartilage with thickness ≥1.0 mm in each segment. The tibial MME area (mm2) and volume (cm3), excluding osteophytes, were measured by 3-D MRI.

The projected cartilage area ratio (cartilage thickness ≥1.0 mm) at the posteromedial segment was lower than the ratio at the other 3 segments. The cartilage area ratio at the posteromedial segment was not correlated with the MME distance measured by the 2-D MRI, but it was negatively correlated with MME area (r=-0.53, p=0.045) and MME volume (r=-0.62, p=0.016) as measured by 3-D MRI. Overall, the 3-D imaging more accurately reflected cartilage damage.

Both radial tears and posterior horn degeneration can lead to meniscal extrusion. When this injury is seen acutely in younger persons, repairs are often attempted. Recently efforts have been made to do repairs in older individuals. The use of cell-seeded nanofibrous scaffolds to repair radial tears and resulting hoop-structure injuries has been studied for prevention of articular cartilage degeneration using a rabbit model.2

Synovial mesenchymal stem cells were isolated and expanded into sheets that were then wrapped onto poly(e-caprolactone) scaffolds to create stable cell/scaffold tissue-engineered constructs (TECs). Scaffold-alone or TEC + scaffold constructs were then sutured into created radial meniscal defects (12 rabbits in each group).

The TEC-scaffold group maintained the structure of the hyaline cartilage with matrix staining with Safranin O up to 12 weeks after surgery. Although the cartilage coverage decreased in both groups, the TEC-scaffold group did not become significantly worse over time, suggesting stabilization of hoop structure integrity. Only the TEC-scaffold group showed repair tissue that exhibited positive Safranin O staining in the inner zone of the meniscus.

Future studies will be required to determine the role of tissue engineering in the preservation of meniscal coverage in the face of radial tears.

References

  1. Suzuki S, Ozeki N, Kohno Y, Mizuno M, Otabe K, Katano H, Tsuji K, Suzuki K, Itai Y, Masumoto J, Koga H, Sekiya I. Medial meniscus extrusion (MME) area and MME volume determined by 3D-MRI are more sensitive than MME distance determined by 2D-MRI for evaluating cartilage loss in knees with medial meniscus degenerative tears. ORS 2019 Annual Meeting Poster No. 0514.
  2. Shimomura K, Rothrauff BB, Hart DA, Hamamoto S,  Kobayashi M,  Yoshikawa H, Tuan RS, Nakamura N. Enhanced Repair of Meniscal Hoop Structure Injuries Using An Aligned Electrospun Nanofibrous Scaffold Combined with a Mesenchymal Stem Cell-derived Tissue Engineered Construct. ORS 2019 Annual Meeting Poster No. 0519.

What’s New in Foot and Ankle Surgery 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, Chad A. Krueger, MD, JBJS Deputy Editor for Social Media, selected the five most clinically compelling findings from among the 60 noteworthy studies summarized in the May 15, 2019  “What’s New in Foot and Ankle Surgery.”

Syndesmotic Injury

–In a Level-II prospective cohort study, 48 patients were reviewed 12 months after transsyndesmotic stabilization with 1 or 2 quadricortically positioned screws.1 Although malreduction of >3 mm or 15° rotation was observed in 30% of the patients, outcome scores were equivalent compared with patients in the anatomically reduced group. Age, obesity, fracture pattern, and screw configuration had no effect on functional outcomes.

Total Ankle Replacement

–A Level-II prospective cohort study compared outcomes of older-generation and newer-generation total ankle replacements (n = 170) with ankle arthrodesis (n = 103). At the 3-year follow-up, both replacement and fusion resulted in improved function and reduced pain, and a pooled comparison of all outcome scores revealed no difference between the 2 procedures. However, subset analyses showed that patients who received newer-generation implants had significantly better outcomes than those who underwent arthrodesis.

Pain Management

–A prospective study analyzing opioid utilization among 988 patients following an outpatient foot and ankle surgical procedure found that only 50% of prescribed opioids were utilized.2 Risk factors for increased opioid consumption included continuous infusion catheter or regional-block anesthesia, age <60 years, high preoperative pain levels, and surgery involving the ankle or hindfoot.

Hallux Rigidus

–Authors of a prospective multicenter series followed 80 patients who underwent a first metatarsophalangeal joint arthroplasty with a 3-component, unconstrained, cementless implant.3 They reported significant improvement in AOFAS Ankle-Hindfoot Scale scores and range of motion at a median follow-up of 11.5 years, with 91.5% implant survival at 15 years. Two patients had periprosthetic cysts on the metatarsal side and 13 patients had phalangeal cysts, but the presence of cysts did not influence clinical results. Multivariate analysis showed a correlation between reduced AOFAS scores and arthrosis of the metatarsosesamoid junction, prompting the authors to suggest that the sesamoid should be enucleated in the presence of substantial arthrosis, fracture, or chondromalacia.

Clubfoot

–Deformity recurrence following Ponseti casting is often treated surgically. However, a comparative cohort study of 35 patients found that repeat casting and bracing for recurrent clubfoot resulted in acceptable 7-year outcomes in 26 (74%) of the patients. The authors suggest that in many children repeat casting should be the first-line intervention in relapsed deformity.

References

  1. Cherney SM, Cosgrove CT, Spraggs-Hughes AG, McAndrew CM, Ricci WM, Gardner MJ. Functional outcomes of syndesmotic injuries based on objective reduction accuracy at a minimum 1-year follow-up. J Orthop Trauma.2018 Jan;32(1):43-51.
  2. Saini S, McDonald EL, Shakked R, Nicholson K, Rogero R, Chapter M, Winters BS, Pedowitz DI,Raikin SM, Daniel JN. Prospective evaluation of utilization patterns and prescribing guidelines of opioid consumption following orthopedic foot and ankle surgery. Foot Ankle Int.2018 Nov;39(11):1257-65. Epub 2018 Aug 19.
  3. Kofoed H, Danborg L, Grindsted J, Merser S. The Rotoglide™ total replacement of the first metatarso-phalangeal joint. A prospective series with 7-15 years clinico-radiological follow-up with survival analysis. Foot Ankle Surg.2017 Sep;23(3):148-52.

Electrocautery Damages Metal Hip Implants in 2 Ways

In the setting of revision total hip arthroplasty (THA), the use of electrocautery—and contact between the thermal device and retained components—cannot always be avoided. In the May 15, 2019 issue of The Journal of Bone & Joint Surgery, Sonntag et al. perform two implant-retrieval analyses and a separate in vitro investigation to determine what kinds of damage take place when electrocautery energy meets titanium femoral stems.

The components for retrieval analyses were removed from patients who experienced a fracture of the femoral stem or femoral neck after revision THA. The authors found superficial discoloration and melting marks on the retrieved components, and elemental analysis indicated that material had been transferred from the electrocautery tip. During in vitro testing of 6 titanium alloy femoral stems, the authors found that electrocautery surface damage reduced load-to-failure by up to 47% when compared to undamaged femoral neck specimens. Microscopic analysis revealed notable changes in metal microstructure in electrocautery-exposed components, whereby certain zones exhibited higher strength than others, which, the authors speculate, might result in lower overall fatigue resistance.

Both the retrieval and in vitro analyses showed that electrocautery damage to femoral implants, particularly in the anterolateral region at the base of the neck, reduced implant fatigue resistance. However, the authors say their results need to “be carefully interpreted,” because they are based on only 2 retrievals and a limited number of test specimens. Nevertheless, they conclude that “electrocautery device contact [with femoral implants] should be avoided and the use of conventional scalpels is recommended, where reasonable.”

NYT Cites Hype of Stem-Cell Treatments for Joint Problems

An active, 71-year old man who declined joint replacement in favor of stem-cell treatment is quoted in a recent New York Times article as saying, “They’re really quick to try to give you fake joints and make a bunch of money off you.” But the NYT article goes on to suggest that making money may be the main objective of some of the many hundreds of clinics that have sprung up around the US to offer cell-based injections to people with aging or damaged joints who want relief without surgery.

The article points out that the FDA has “taken an industry-friendly approach toward companies using unproven cell cocktails” and that the scant scientific evidence about these treatments, which include injections of platelet-rich plasma, is inconclusive.

For OrthoBuzz readers who want to dive more deeply into the scientific underpinnings (or lack thereof) related to cell therapies for joint problems, please peruse the following JBJS and JBJS Reviews articles, which have been made openly available for a limited period of time:

The main message running through all these articles is this: Effective clinical assessment and safe, optimized use of cell-based therapies demands greater attention to study methods; standards for cell harvesting, processing, and delivery; and standardized reporting of clinical and structural outcomes.

The Economics of Revision THA for Fractures: Sustainable?

At the risk of  economic oversimplification, it is difficult to sustainably provide a service when payment for it is less than the cost to perform it. But that is one reality exposed by Hevesi et al. in the May 15, 2019 issue of The Journal. Using National Inpatient Sample and ACS-NSQIP data, the authors compared the average costs and 30-day complication rates for revision total hip arthroplasties (THAs) performed for 3 different indications—fractures, wear/loosening, and instability—at both a local and national level. They found that the average hospitalization costs associated with a revision THA related to a fracture were 33% to 48% higher (p < 0.001) than the cost of revision THAs related to wear or instability.

However, the authors emphasize that all 3 of these indications for revision THA are reimbursed at the same rate based on Medicare Diagnosis-Related Group (DRG) codes. DRGs take into account patient comorbidities to determine reimbursement levels—but they do not adjust payments for THA revision according to indication. Hevesi et al. note that the only DRG reimbursement level that would cover the average cost of a revision THA for a fracture would be one performed on a patient with severe medical comorbidities or a major complication. Not surprisingly, patients who underwent a revision THA to treat a fracture were found to have a higher age and more medical comorbidities than those undergoing a revision for wear or instability.

The authors use this data to make a very compelling case that DRGs for revision THA should be changed so they are indication-specific, taking into account the underlying reason for the revision. They observe that “a DRG scheme that does not distinguish between indications for revision THA sets the stage for disincentivizing the care of fracture patients and incentivizing referrals to other facilities.” Those “other facilities” usually end up being large tertiary-care centers, which the authors claim “perform a higher percentage of the costlier revision THA indications.”

This problem of reimbursement inequality is not unique to revision THAs and requires further investigation in many fields. Unless “the system” addresses these subtle but important differences, tertiary referral centers may be inundated with patients who need procedures that cost more to perform than the institutions receive in reimbursement—an unsustainable scenario.

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

May 2019 Article Exchange with JOSPT

In 2015, JBJS launched an “article exchange” collaboration with the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) to support multidisciplinary integration, continuity of care, and excellent patient outcomes in orthopaedics and sports medicine.

During the month of May 2019, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “Cervical Muscle Endurance Performance in Women With and Without Migraine.”

The authors of this cross-sectional laboratory study found that a group of 26 female patients with migraine exhibited a lower holding time for both neck-extensor and neck-flexor endurance than a group of 26 women without migraine. Both groups reported a similar level of neck pain, but only individuals in the migraine group reported pain referred to the head during testing.

Trauma in the Developing World: A Call to Action

Over the past decade and a half, the problem of musculoskeletal trauma has been identified as impacting more individuals in developing countries than HIV, drug-resistant tuberculosis, and other infectious diseases that are commonly recognized as public health crises. The need for access to surgical treatment for patients who sustain traumatic injuries has recently garnered more attention. Yet funding from nongovernmental organizations and other national/international foundations has not reached the levels necessary to appropriately address this important public health issue.

In the May 15, 2019 issue of The Journal, Agarwal-Harding et al. document the issue of patients experiencing delayed access to musculoskeletal trauma care in the sub-Saharan country of Malawi. Thanks to the development of a trauma-care registry serving both rural and urban health centers in Malawi, the authors were able to clarify the factors associated with delayed presentation for care.

Not surprisingly, those factors included distance from treatment centers and sustaining an injury during a weekend. These issues are likely widespread throughout Africa and in many other developing countries, where EMS services are sparse at best and treatment facilities are generally under-resourced. Although an increasing number of people in developing countries are being injured in road/vehicle-related accidents, many of the patients evaluated in this study did not experience high-energy trauma, but were instead injured from falls and during sporting activities. In short, they experienced the types of injuries that are likely to occur to everyday people doing everyday activities anywhere in the world.

The issue of delayed access to care is addressable if we continue to acknowledge the incredible public health burden that musculoskeletal trauma places on individuals and society within the developing world. These injuries not only affect patient quality of life, but they also have large impacts on families and communities due to a loss of income or disability-imposed restrictions on community engagement. Addressing this issue is of great interest to the readers of JBJS, who are volunteering to serve the orthopaedic needs of the developing world in ever-increasing numbers.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Which Germs Cause Pelvic Prosthesis Infections?

Prosthetic infections involving total hip or knee implants are bad enough, but infections involving pelvic endoprostheses following tumor resection can be particularly devastating, often necessitating multiple surgical interventions. And, such infections are disconcertingly common, affecting an estimated 11% to 53% of pelvic endoprostheses.

Findings from a retrospective multisite cohort study by Sanders et al. in the May 1, 2019 issue of The Journal of Bone & Joint Surgery reveal more about the specific microorganisms underlying those infections—and may offer insight into how to prevent them.

The authors analyzed 70 patients who underwent pelvic endoprosthetic reconstruction following a tumor resection. Eighteen patients (26%) developed an infection, and in 14 out of those 18 cases, the infection was determined to be polymicrobial. Cultures from 12 of the 18 patients (67%) were positive for a member of the Enterobacteriaceae family of gram-negative bacteria, which includes Escherichia coli. More generally, microorganisms associated with intestinal flora appeared 32 out of the 42 times that any microorganism was isolated.

At the latest follow-up (median follow-up was 66 months), 9 of the 18 patients still had the original implant, although 2 of those patients had a fistula and another 2 were receiving suppressive antibiotics. Of the remaining 9 patients who had the original implant removed, 3 had a second implant in situ.

The authors emphasize how different these pelvic endoprosthetic infections are from infections related to joint arthroplasty. The close proximity of incisions for periacetabular tumor resection to the gut and other highly colonized areas might contribute to these infections, they speculate. Sanders et al. say the findings of this study may prompt surgeons to employ additional surgical-site antiseptic measures before and during these surgeries and “may justify the use of a broader spectrum of [systemic] antibiotic prophylaxis aimed at gram-negative bacteria.”  They also suggest that investigations into “selective gut decontamination” might yield additional information about how to prevent infections in this surgical setting.

Whole-Slide View of Rare Orthopaedic Tumor

JBJS Case Connector debuted digital whole-slide images back in 2016, and the February 27, 2019 case report by Lans et al. put that ability to link to and navigate an entire microscope slide to good use again.

The 27-year-old man described in this case report presented with a progressively painful right forearm. Conventional radiographs and MRI led clinicians to suspect a rare desmoplastic fibroma of the proximal aspect of the radius, but it was not until a CT-guided core biopsy was analyzed histologically that the diagnosis could be confirmed. The histologic findings, depicted in a digital whole-slide image, revealed a fibrous to fibro-osseous lesion composed of fibroblast-like cells with varying degrees of hypercellularity.

The patient subsequently underwent a wide-margin resection that preserved the radial head but created an 8.5-cm defect, which surgeons reconstructed with a vascularized fibular autograft. At the 2-year follow-up, the patient’s QuickDASH score was 2.7 and his PROMIS Upper Extremity and Physical Function Short Form score was 42.

For more information about JBJS Case Connector, watch this video featuring JBJS Editor-in-Chief Dr. Marc Swiontkowski.

Physician Practice Changes After Paying Malpractice Claims

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

Malpractice. The word itself causes a visceral reaction for many of us in medicine. Although the vast majority of physicians will not pay a malpractice claim during their careers, there is still concern about the quality of care provided by doctors with multiple claims paid, either through out-of-court settlements or through court verdicts. The National Practitioner Data Bank (NPDB) was created, in part, to help prevent a doctor with a long list of malpractice claims paid from moving to a new geographic area for a “fresh start” without full disclosure of his or her claims history.

In the March 28, 2019 issue of The New England Journal of Medicine, Studdert et al. examined changes in practice characteristics among physicians who had paid malpractice claims from 2003 through 2015. By linking the NPDB to Medicare data, the authors identified a cohort of >480,000 physicians, 89.0% of whom had paid no malpractice claims. Nearly 9% of physicians had one paid claim, while the remaining 2.3% of physicians had two or more paid claims. That 2.3% accounted for 38.9% of all the claims paid during the study period.

A total of 19,098 (4%) of claims paid were in orthopaedic surgery, which made it the seventh most-sued specialty studied. When evaluating the subgroup of all physicians with ≥3 claims paid, the authors noted that they were more likely to be male, 50 years of age or older, and to practice in surgical specialties. In multivariate analysis, physicians with at least one paid claim were more likely to leave the practice of medicine than those with none. Finally, physicians with multiple paid claims were more likely to switch into small or solo practices, but the study found “no clear association between the number of claims and the propensity to relocate, within or between states.”

To be clear, the number of malpractice claims paid by a doctor is not necessarily a reliable indicator of quality of care, though many patients arrive at that conclusion. Just as important, this study doesn’t conclude that solo practitioners—in orthopaedics or any other specialty—are more likely to have paid a higher number of claims. There are many excellent physicians in solo practices across the United States.

Ultimately, this study shows that the majority of physicians have not paid a single malpractice claim and that physicians who have paid multiple claims are not more likely than other doctors to relocate their practice. These findings should help patients trust the various procedures that are in place to prevent the exceedingly small number of physicians with a long list of malpractice payouts from relocating in an attempt to leave their history behind them. From the physician viewpoint, the findings emphasize that the impact of malpractice claims goes beyond the emotional and personal into the realm of prompting changes in practice environment.

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.