Articular cartilage is a unique and complex tissue. The interactions among chondrocytes, water, and matrix macromolecules provide articular cartilage with its special properties, including the absorption and distribution of compressive loads and low-friction articulation of synovial joints. However, this complex, unique, and sophisticated tissue does not repair itself well and cartilage repair recently has become the target of numerous investigations. Indeed, the natural history of articular cartilage defects is not well defined and thus the development of treatment strategies has been limited. One technique that has gained some success is microfracture.
Microfracture is a commonly employed operative technique that is considered to be safe, relatively inexpensive, and minimally invasive as a first-line treatment for small, contained articular cartilage defects. The scientific basis of microfracture is that disruption of blood vessels in the subchondral bone will cause bleeding in the cartilage defect, leading to the formation of a fibrin clot. It has been suggested that if the clot is protected from loading, undifferentiated mesenchymal stem cells from the bone marrow will migrate into the defect, proliferate, and differentiate into fibrochondrocytes. These chondrocytes then synthesize a fibrocartilaginous matrix that fills the defects. Evidence has shown that microfracture has acceptable short-term clinical results, but those results can be expected to decline over time. What is most important for the surgeon is to determine which patients are the best candidates for this procedure and which patients should not be so treated.
Determining which patients and which cartilage defects are best treated with microfracture can be difficult. Moreover, as the results have been reported over the years, the indications for this technique have narrowed. Clinical experience has shown that lesions measuring >4 cm2 have been associated with worse outcomes. On the other hand, the minimum defect size for which microfracture should be used has not been clearly defined. Another factor is age, with younger patients having better clinical outcomes. Defect location also affects outcomes, with better results having been reported following the treatment of defects involving the femoral condyles. Finally, body mass index (BMI) is a potential risk factor for the failure of this procedure as patients with a BMI of >30 kg/m2 have had significantly lower outcomes scores and subjective ratings compared with those with a BMI below that threshold.
In the June 2016 issue of JBJS Reviews, Sommerfeldt et al. provide a critical overview of microfracture. The authors conclude that microfracture is likely to produce acceptable clinical results in the short term but that the results cannot be guaranteed over the long term. This is an important article for orthopaedic surgeons who perform this technique and for surgeons who seek to understand the basic mechanisms that support this treatment modality.
Thomas A. Einhorn, MD
Editor, JBJS Reviews
The Orthopaedic Trauma Association (OTA) just launched a page on its website devoted to disaster-preparedness resources for surgeons and first responders.
Titled “Get Prepared,” the page includes:
- A 93-slide PowerPoint presentation on orthopaedic blast injuries
- Courses from the National Disaster Life Support Foundation and the American College of Surgeons’ Committee on Trauma
- A bibliography with links to the JBJS Reviews article “Disaster Response Management Protocol for Departments of Orthopaedic Surgery” and the JBJS/JOSPT Special Report It Takes a Team—The 2013 Boston Marathon.
Maybe—but only if larger, longer-term studies replicate the findings from a randomized trial of 144 patients (mean age = 66 years) published recently in the Annals of the Rheumatic Diseases.
Subjects with knee osteoarthritis (OA) in the double-blind Annals study received either placebo or up to 25 mg per week of oral methotrexate over a 28-week period. At 28 weeks, researchers found greater reductions in knee pain and larger improvements in scores of physical function and activities of daily living in the methotrexate group than in the placebo group. The authors also noted a significantly greater reduction in synovitis, measured both clinically and with ultrasound, in the methotrexate group relative to the placebo group.
Methotrexate is a powerful drug prescribed to treat certain cancers and refractory rheumatoid arthritis, but it has many well-known and potentially serious side effects, such as hematopoietic suppression and liver toxicity. Nevertheless, these authors reported few adverse events; those that did occur included self-limiting mucositis, alopecia, GI disturbance, and transaminitis.
While some people are thought to have a more inflammatory phenotype of osteoarthritis than others, this study did not stratify patients along inflammatory lines, so further research will be needed to determine whether methotrexate’s clinical benefits accrue equally to OA patients generally, or mostly to those with the inflammatory subtype.
OrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation about these classics by clicking on the “Leave a Comment” button in the box to the left.
Austin Moore’s article “The Self-Locking Metal Hip Prosthesis” was published in The Journal of Bone & Joint Surgery in 1957. Dr. Moore had a lifelong professional interest in hip-fracture surgery and was well aware of the problems associated with reduction and fixation of displaced femoral neck fractures. He had previously designed an internal-fixation device for the management of these injuries and had recognized that perfect reduction, accurate placement of the hip nail, and 100% compliance with non-weight bearing were prerequisites for a satisfactory outcome. For patients in whom those criteria could not be met or those in whom reduction and fixation had failed, an alternate method of managing these fractures was required.
Fourteen years prior to the publication of this landmark article, Dr. Moore had published a case report in The Journal (July 1943) in which he documented the use of a metal prosthesis to replace the proximal end of the femur for a patient with an aggressive giant cell tumour. Some years later the patient succumbed from other causes and the femur was retrieved at autopsy. The specimens demonstrated satisfactory osseointegration of this implant in the proximal femur and encouraged Dr. Moore to experiment with a number of models of proximal femoral implants. This progression of implant design and usage is carefully outlined in this classic paper, which is amply illustrated with radiographs and autopsy specimens of the evolving prosthesis that eventually became known as the Austin Moore hip prosthesis.
This paper is notable for a number of reasons. First, Dr. Moore was able to demonstrate satisfactory fixation using an intramedullary stemmed implant—a significant departure from the early efforts of the Judet brothers and others, who used a small stem in the residual femoral neck in patients being treated for hip arthritis. Secondly, the author developed a specific surgical approach allowing for the insertion of these slightly curved stems into the femur—an approach that is still used today in a number of surgical hip procedures.
Third, Dr. Moore demonstrated the usefulness of proximal femoral replacement in acute displaced femoral neck fractures, avascular necrosis following femoral neck fracture, and non-unions of the femoral neck. He further expanded the use of this implant in the treatment of hip arthritis and documents a number of such cases in this article.
Throughout the article, Dr. Moore emphasizes the importance of meticulous surgical technique, the use of bone ingrowth fixation, careful sizing of the femoral head to the native acetabulum, and the importance of conscientious post-operative care. Finally, he recognized the importance of routine follow-up of endoprostheses and insisted on a yearly visit to ensure appropriate integration of the prosthesis.
In summary, with this article Dr. Moore started a trend of endoprosthetic treatment for displaced femoral neck fractures that is now the standard of care throughout much of the world. During the development of this technique, he demonstrated the importance of bone ingrowth as a method of stabilizing the prosthesis, the importance of good surgical technique, and the value of long-term follow-up in managing patients with hip prostheses. The fact that the implant he designed and reported on 60 years ago is still in widespread use is a reflection of his vision.
James P. Waddell MD, FRCSC
JBJS Deputy Editor
This month’s Image Quiz from the JBJS Journal of Orthopaedics for Physician Assistants (JOPA) highlights the case of an 8-year-old boy who presents with a 3-month history of in-toeing. Anteroposterior pelvic and bilateral frog-leg radiographs are included, along with measurements of the foot progression angle, medial rotation of the hip, and the thigh-foot axis.
The Image Quiz reviews the natural history of lower-extremity rotational deformities in children, and describes in detail how to make the physical-examination measurements that helped answer the clinical question of whether this patient’s in-toeing was benign or a sign of a more serious deformity.
When Verburg et al. designed their randomized clinical trial, published in the June 15, 2016 edition of The Journal of Bone & Joint Surgery, they hypothesized that a mini-midvastus (MMV) approach to total knee arthroplasty (TKA) would yield better outcomes than a conventional approach. However, during short- and mid-term follow-up (up to 5 years postoperatively) on 84 TKAs (42 in each group), the researchers found no relevant clinical or radiographic differences between the two groups, both of which received the same brand of posterior-stabilized implant.
On average, the MMV procedure took 6 minutes longer, and those in the MMV group had better range of motion on postoperative day 3. On the downside, more wound-healing problems such as blisters were observed in the MMV group, especially in large male patients, which the authors attribute to soft-tissue interactions caused by the use of necessarily large components with small incision lengths.
Verburg et al. concluded that “the advantage of the MMV approach was merely a smaller scar,” and they do not recommend MMV or other minimally invasive/quadriceps-sparing approaches for “larger patients or muscular men.”
Late last summer, JBJS began offering KUDOS as a free service to authors. KUDOS is an easy-to-use tool that helps authors boost and measure the impact of their published work.To date, 159 JBJS authors have registered with KUDOS.
Recently, KUDOS applauded Dr. Alejandro Marquez-Lara, co-author of a JBJS Reviews article about the effects of NSAIDs on bone healing, for his exemplary job summarizing and explaining the importance of his study.
On KUDOS, Dr. Marquez-Lara said the article “provides insight into the disconnect between basic science and clinical literature” on this controversial topic. He explained the predicament this way: “There is no clear evidence to support that NSAIDs inhibit bone healing in the clinical setting…but there is also no good evidence confirming the safety of NSAIDs with regards to bone healing.” He concluded by encouraging orthopaedists “to read this review to improve the quality of ongoing and future clinical studies.”
Click here to learn more about how KUDOS works and how it can help JBJS authors enhance the visibility and influence of their published research.
New subspecialty CME exams are now available from The Journal of Bone & Joint Surgery in the following topic areas:
- Adult Hip Reconstruction
- Adult Knee Reconstruction
- Shoulder and Elbow
- Sports Medicine
Each exam consists of 10 questions based on articles published in JBJS within the past 12 months. Exams can be used for study purposes at no cost. Each exam activity may be submitted for a maximum of 5 AMA PRA Category 1 Credits™.
Despite the relative rarity of necrotizing fasciitis (NF), orthopaedists can expect to see at least 1 case of NF in their career. This month’s “Case Connections” springboards from a recent case report about necrotizing fasciitis in which the infectious source was highly unusual, followed by three additional case reports related to NF from the JBJS Case Connector archives
- In the June 8, 2016, edition ofJBJS Case Connector, Connor et al. reported on the case of a 70-year-old man who developed necrotizing fasciitis of the thigh and calf through a colon perforation caused by sigmoid diverticulitis.
- Zani and Babigian described a case of NF in the shoulder of a 53-year-old woman following acromioplasty and open rotator cuff repair.
- The bacteriumAeromonas hydrophila caused NF in a 58-year-old non-immunocompromised man, as described in a case report by Borger van der Burg et al.
- Cheng et al. described 3 fatal cases of necrotizing fasciitis caused by methicillin-resistant Staphylococcus aureus(MRSA).
Time and teamwork are of the essence in the management of necrotizing fasciitis. To hasten diagnosis, clinicians are advised to submit blood and tissue samples for pathological analysis as soon as possible. A multidisciplinary team that includes an infectious-disease specialist should be assembled in cases of suspected NF.
James H. Beaty, MD—chair of the JBJS, Inc. Board of Trustees and past president of the AAOS—is the new chairman of the Department of Orthopaedic Surgery and Biomedical Engineering at the University of Tennessee-Campbell Clinic. Dr. Beaty joined the Campbell Clinic in 1982 as a specialist in pediatric orthopaedics and pediatric trauma and served as the renowned institution’s chief of staff from 2001 to 2010.
A past president of the American Board of Orthopaedic Surgery and the Pediatric Orthopaedic Society of North America, Dr. Beaty has also authored 58 book chapters and nearly 70 peer-reviewed scientific articles.
In an interview with Orthopedics This Week, Dr. Beaty said,”My initial goal is to continue our progress in building both translational and basic research in our department.”