Are Outcomes After Total Ankle Replacement Similar In Patients With Rheumatoid Arthritis And Osteoarthritis?

How might the unique characteristics of rheumatoid arthritis affect outcomes after total ankle replacement (TAR)? 

A recent study online in Foot and Ankle International compared several outcome measures over three years in 45 patients with end-stage osteoarthritis and 19 patients with rheumatoid arthritis. All patients underwent TAR with a three-component mobile-bearing system. Surgeons followed standard guidelines for perioperative management of anti-rheumatic medication modified from total hip and knee replacement surgery protocols. 

American Orthopaedic Foot and Ankle Society (AOFAS) scores, the Foot and Ankle Outcome Score (FAOS) and Foot and Ankle Ability Measure (FAAM) all showed no significant difference between the cohorts at the preoperative, postoperative and final evaluations. Perioperative complications and revision rates also were statistically similar between patients with rheumatoid arthritis and osteoarthritis. The only areas in which outcomes were significantly different were those related to sports activity. Patients with osteoarthritis exhibited higher FAOS sports and leisure and FAAM sports activity scores. 

Jeffrey E. McAlister, DPM, FACFAS shares that rheumatoid arthritis is a commonly-seen form of ankle arthritis in his practice, second only to post-traumatic arthritis. 

Stephen Brigido, DPM, FACFAS concurs, estimating that 20 to 30 percent of his patients who need ankle replacement have rheumatoid arthritis or another form seronegative arthritis. 

Christopher F. Hyer, DPM, FACFAS relates that total ankle replacement can work well in patients with rheumatoid arthritis, but notes that these patients often have more associated medical complexity. 

“One needs to have awareness of surrounding joint deformities, the use of anti-rheumatic drugs and steroids, and bone density as it relates to implant security and possible intraoperative complications,” he says. 

Elaborating on the unique challenges of joint replacement in patients with rheumatoid arthritis, Dr. McAlister says that they can vary from patient to patient, but agrees medications and bone quality are important concerns. 

“I also find that these patients typically are not quite as active and are not able to recover as quickly,” he adds. “This also makes the lower functional outcomes sports-related scores not surprising.” 

Skin structure protection is also paramount in patients with rheumatoid arthritis, Dr. Brigido goes on to say, adding that he carefully educates patients on this point, due to potential concerns for wound healing. 

“Often a rheumatology consult is necessary to see what medications one can pause or exchange to reduce healing and infection risks,” explains Dr. Hyer. “Many times these patients are older and may have lower bone density related to age or medications.” 

He goes on to add that supplemental prophylactic fixation of the malleoli during total ankle replacement may reduce the patient with rheumatoid arthritis’ chances of intra-operative fracture. 

Dr. McAlister stresses that a key point in this study is the lack of increase in complications in the cohort with rheumatoid arthritis. 

“This study highlights the fact that our rheumatoid patients and osteoarthritis patients have similar outcomes. We can now have conversations with our rheumatoid arthritis patients, giving them hope that they will have a successful surgical result,” says Dr. McAlister, in practice in Scottsdale and Phoenix, Ariz and Co-Founder of Ankle Arthritis Centers. 

Dr. Brigido, in practice in Allentown and Bethlehem, Pa., agrees, adding that surgeons can articulate to patients that their disease does not prevent them from pursuing reduced pain and improved mobility. 

“I think this study highlights that TAR is a reasonable and useful treatment option for end-stage ankle arthritis regardless of the cause and can provide lasting pain relief,” adds Dr. Hyer, in practice in Worthington, Ohio. 

Which Classification System Is Most Reliable For Diabetic Charcot Neuroarthropathy? 

By Jennifer Spector, DPM, FACFAS, Managing Editor

As multiple classification and staging systems exist, researchers set out to assess intra- and inter-reader reliability of the Sanders/Frykberg classification, the Brodsky/Trepman classification and the Eichenholtz staging systems for Charcot neuroarthropathy. In a recent study in the Journal of Foot and Ankle Surgery, five physicians underwent specific training before evaluating digital radiographic images of 55 patients with Charcot neuroarthropathy and five patients without, according to each of the systems in question. 

The Sanders/Frykberg classification showed the best inter-reader performance, rated as “excellent reliability,” based on the 95 percent confidence interval of the intraclass correlation coefficient estimate. The Trepman/Brodsky classification revealed “good to excellent” reliability and the Eichenholtz staging system exhibited “moderate to good” reliability. 

Dane K. Wukich, MD, lead author on the study, relates that ideally, a classification system helps guide treatment and prognosis. “In regards to Charcot neuroarthropathy, there is still debate on multiple aspects including the timing of surgical intervention and methods of fixation. There is no consensus on these topics and the available classification systems do not address this.” 

Katherine M. Raspovic, DPM, FACFAS, another author on the study, adds that the two commonly used anatomic classifications for Charcot are more than two decades old and Eichenholtz staging is greater than five decades old. 

“These systems are based on conventional radiographs,” she explains. “Conventional radiographs do not identify patients in Stage 0 and may miss subtle findings in Stage 1.” 

“Classification systems are an important means of communication among physicians,” elaborates Dr. Wukich, Professor and Chair of the Department of Orthopaedic Surgery at the University of Texas Southwestern Medical Center in Dallas, Tx. “The ideal classification system must have high reproducibility and prognostic value and can help guide treatment.” 

Drs. Wukich and Raspovic share that the level of reliability of each of the systems was better than expected, so they feel that these classification systems can still be useful to help communicate between physicians treating these patients. 

“All investigators in this study are fellowship-trained foot and ankle surgeons at an academic medical center who routinely treat patients with Charcot. Because of this, the results may not be generalizable to providers who do not routinely evaluate and treat this condition, which is one of the main limitations of the study,” says Dr. Raspovic, who is an Associate Professor in the Departments of Orthopaedic and Plastic Surgery at the University of Texas Southwestern Medical Center in Dallas, Tx. 

What Do We Know About The Cutaneous Microbiome Of The Diabetic Foot? 

By Jennifer Spector, DPM, FACFAS, Managing Editor 

Aposter abstract accepted for the upcoming Symposium on Advanced Wound Care Spring/ Wound Healing Society Wound Care Week took a closer look at the composition of the pedal cutaneous microbiomes of patients with and without diabetes to see if differences could be a contributor to diabetic foot infections. 

In 30 patients so far, a single-center, analytical, cross-sectional study compared swab cultures of the right plantar forefoot and interdigital spaces using next generation sequencing for bacterial and fungal species. The data collected revealed the most prevalent bacterial species as Staphylococcus pettenkoferi and Staphylococcus hominis. Ascomycota sp. and Fungi sp., although only identifiable at the phylum and kingdom levels, respectively, were the most abundant fungal species. 

All samples revealed bacterial dermal pathogens, and 90 percent exhibited fungal pathogens at different levels of prevalence. Citing the complexity of the human cutaneous microbiome, the abstract concludes that further study may enhance treatment and management strategies to prevent diabetic foot infections. 

Windy Cole, DPM, author of the abstract, notes the contrast between the pedal cutaneous microbiome observed in this study and that of the gastrointestinal tract. 

“Unlike the diverse microbes seen in healthy gastrointestinal tracts, our data set obtained from intact skin in both study groups showed lack of diversity with 73 percent of samples showing either a bacterial or fungal overgrowth, where one species represented more than 50 percent of the bacterial or fungal composition,” she explains. 

When asked about what providers can learn from the data so far, Dr. Cole relates that simply detecting a pathogen present in the microbiome did not always indicate a disease state or warrant antibiotic treatment. 

“This abstract represents an interim analysis of data collected in an ongoing study. We plan to publish final findings once the study enrolls and processes specimens on 100 subjects, 50 with diabetes and 50 without,” says Dr. Cole, an Adjunct Professor and Director of Wound Care Research at the Kent State University College of Podiatric Medicine.