Study Shows Low Nonunion Rate For Arthrodesis

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By Brian McCurdy, Associate Editor

A new study on Lapidus arthrodesis presents some encouraging results. In a retrospective study of over 200 patients who underwent the Lapidus arthrodesis procedure, the researchers found only a 5.3 percent nonunion rate. The study, which was recently published in The Journal of Foot And Ankle Surgery (JFAS), assessed the results of a modified procedure, which emphasized joint curettage with subchondral plate preservation and screw fixation. The low nonunion rate is the most significant finding in the study, according to study co-author Lawrence Ford, DPM. “A lot of people believe that removing the subchondral plate is necessary to increase likelihood of union,” says Dr. Ford, a Fellow of the American College of Foot and Ankle Surgeons. "Our study shows that preserving the subchondral plate not only limits the amount of shortening of the first ray, but may facilitate union." Postoperatively, Dr. Ford and his co-authors used a standard nonweightbearing protocol of six to eight weeks and tracked the patients for at least six months. Out of the 227 feet (in 211 patients) treated for forefoot pathology, only 12 feet had nonunion. Dr. Ford notes the JFAS study concurs with a cadaveric study by Ronald Ray, DPM. He says Dr. Ray’s study concluded that fixation across the subchondral plate may increase the fusion site’s stability. How one prepares joint surfaces for fusion “may be a significant factor” in shaping the outcome of the Lapidus arthrodesis, according to the study. The authors note their curettage procedure preserved the subchondral plate. They say this results in increased stability. Even in the 12 cases of nonunion, Dr. Ford and his co-authors note that only two of these feet “lost correction of the first ray.” The study also notes that appropriate screw placement can optimize the dispersion of force through the length of the screws and help facilitate union. Emphasizing Appropriate Patient Education And Patient Selection The authors of the study emphasized the importance of educating patients about nonweightbearing, noting that noncompliance with the nonweightbearing instructions contributed to four of the 12 nonunions. Dr. Ford also points out that they considered smoking a contraindication for Lapidus arthrodesis. He says this may also explain the low rate of nonunion. Despite the findings of the study, Dr. Ford cautions that one must still weigh the risk of nonunion when considering the Lapidus arthrodesis. “It is important to understand that nonunion is inherent to the procedure,” he notes. “Although the rate of 5.3 percent compares favorably to the literature, it is still a real potential complication of the Lapidus.” New Study Sheds Light On Detecting Peroneus Brevis Tendon Tears By Brian McCurdy, Associate Editor Diagnosing peroneus brevis tendon tears can be difficult. In a new retrospective study on the subject, researchers have found that these tears rarely present as isolated injuries. The study, which was recently published in the JFAS, reviewed preoperative MRIs and intraoperative findings for 32 patients who underwent surgery for longstanding peroneus brevis tendon pathology. The authors found an array of coexistent conditions with peroneus brevis tendon tears. These conditions included: • low-lying muscle belly/peroneus quartus in 44 percent of the cases; • anterior talofibular ligament rupture in 50 percent of the cases; • a flattened/hypertrophic peroneus longus tendon in 53 percent of the cases; and • a flat/convex fibular groove in 78 percent of the patients. “(Peroneus brevis tendon tears) are part of a constellation of pathologies that coexist when patients suffer from lateral ankle pain and instability,” says study co-author Alan Catanzariti, DPM, a Fellow of the American College of Foot and Ankle Surgeons. The authors of the study also noted that magnetic resonance imaging (MRI) successfully diagnosed peroneus brevis tendon tears in 26 of the 32 patients. “In conjunction with a careful physical examination, (MRI) plays a valuable role in the preoperative assessment of the peroneal tendons and the entire lateral ankle complex,” the researchers note in the study. However, even with the MRI, the peroneus brevis tendon tears remain difficult to detect according to the study authors, who note that there were four false positives and two false negatives. Specifically, they point out in the study that the peroneus brevis was flat in two cases and they encountered a hypertrophic peroneus longus in three cases, making detection of the tendon tears more difficult. Given the strong possibility of coexisting conditions and the difficulty in detecting the peroneus brevis tendon tears even with MRI, one should pursue a thorough diagnostic work-up prior to surgery, notes Dr. Catanzariti, the Director of Residency Training Programs for the Division of Foot and Ankle Surgery at the Western Pennsylvania Hospital in Pittsburgh, Pa. “Physicians should consider a work-up for concomitant lateral ankle pathology before instituting treatment for peroneus brevis tendon tears,” says Dr. Catanzariti. International Conference Joins DPMs And Orthopedic Surgeons By Brian McCurdy, Associate Editor Podiatric surgeons and orthopedic surgeons will come together for the first International Foot and Ankle Congress later this month. Organizers and lecturers have hailed the upcoming meeting for its historical significance. “This meeting is the first that has this kind of representation of the two professions that virtually have the same scope of practice,” says Lowell Scott Weil, Sr., a Fellow and Past President of the American College of Foot and Ankle Surgeons. Foot and ankle surgeons will speak on a wealth of topics, including forefoot pathology, hallux valgus and primary first ray pathology, new techniques in heel pain surgery and limb salvage. Dr. Weil adds that one lecture will discuss the idea of transplanting an entire ankle from a cadaver to a patient who is suffering from ankle arthritis. Another highlight of the meeting will be a lecture by Lowell Scott Weil, Jr., DPM, who will be presenting the results of three FDA double-blind, randomized, placebo-controlled studies on extracorporeal shockwave therapy. While the lectures and research presented at the meeting will be major draws, Dr. Weil Sr. says the sharing of ideas between the two professions may have a lasting impact beyond any individual topic or lecture. “Meetings such as this will only lead to better cooperation between these groups that will ultimately lead to greater acceptance and credibility for podiatric physicians to practice within the mainstream of medicine,” explains Dr. Weil, who will be lecturing on adult-acquired flatfoot. “In the long run, the beneficiaries will be the patients, who will be better served by both professions.” The International Foot and Ankle Congress will be held from April 28 to May 1 at the New Orleans Marriott in New Orleans. For more information, call (770) 939-0393 or check out www.ifacneworleans.com. Clarifications The following company listing was omitted from the 2004 Commercial Desk Reference: Fine Surgical Instruments, Inc. 741 Peninsula Boulevard Hempstead, N.Y. 11550 Phone: (516) 292-7400 or (800) 851-5155 Fax: (516) 292-7484 E-mail: sales@finesurgical.com www.finesurgical.com In regard to the Practice Builders column, “How To Establish And Maintain A Diabetic Shoe Program,” in the October 2003 issue, the American Diabetes Association does not provide mailing lists of patients with diabetes. In regard to the Diabetes Watch column, “What The ADA Says About Pre-Diabetes And Exercise,” in the February 2004 issue, guest author Steven Miller, DPM, notes: “The American Diabetes Association has officially adopted the recommendation to change the range of impaired fasting glucose from 110-125 mg/dL to 100-125 mg/dL. Thus, any fasting glucose value of 100 or greater is considered abnormal and may require additional testing.”

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