Elizabeth Hofheinz, M.P.H., M.Ed
New work from Hospital for Special Surgery (HSS) in New York has looked at eight patients who had a limb deformity and end-stage ankle osteoarthritis (OA) and underwent staged deformity correction and total ankle arthroplasty (TAA).
The study, “A Staged Approach to Combined Extra-articular Limb Deformity Correction and Total Ankle Arthroplasty for End-Stage Ankle Arthritis,” appears in the March 2021 edition of Foot & Ankle International.
Co-author Scott J. Ellis, M.D., a foot and ankle surgeon at HSS, told OSN, “We were performing cases in which we were successfully combining the expertise of the limb lengthening and the foot and ankle services at HSS to achieve successful results in cases where we had to align the leg before carrying out a total ankle replacement.”
The cases (2016 to 2019), retrospectively identified from the HSS database, had an average age of 58.5 years (average followup 2.6 years). Limb reconstruction was either conducted with a tibial osteotomy with a circular frame (n=6) or an intramedullary nail (n=2). Limb deformities were: posttraumatic tibial malunion (2), limb length discrepancy (1), acquired tibial deformity (1), genu varum (2), or genu valgum (2).
The pre- and postoperative parameters examined on 51-inch standing and ankle radiographs: limb length discrepancy (LLD), genu varum/valgum deformity, recurvatum deformity, mechanical axis deviation, medial proximal tibial angle, lateral distal tibial angle, anterior distal tibial angle, and tibiotalar alignment.
As for pre- and postop patient-reported outcomes, the researchers used two metrics: the Limb Deformity–Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) scores (Physical Function, Pain Intensity, Pain Interference, Global Physical Function, and Global Mental Function).
Dr. Ellis commented to OSN: “It was fascinating to find that we could have Drs. S. Robert Rozbruch (chief of Limb Lengthening and Complex Reconstruction Service at HSS) and Austin Fragomen (limb lengthening surgeon at HSS) correct a wide variety of deformity in the tibia, as well as limb length discrepancy prior to total ankle replacement in patients with severe ankle arthritis.”
“Successful results in total ankle replacement can be achieved only when correct alignment is obtained at the time of surgery. Sometimes, however, when there are deformities of the tibia or femur (either from congenital problems or previous trauma), much more complex correction of the deformity is required above the level of the ankle before a total ankle replacement can even be considered.”
Asked why this is a new topic in the literature, Dr. Ellis told OSN: This has not been studied before because this work can generally only occur at a center with expertise in both tibial osteotomy alignment and total ankle replacement. The study required collaboration between the two services. Also, these cases are not very common, making such a large number of cases not readily accessible.