SLR - October 2020 - Isaac Wilhelm

Treating AO/OTA 44b Lateral Malleolar Fracture in Patients Over 50 Years of Age: Periarticular Locking Plate Versus Nonlocking Plate

References: Shih, Chien-An, I.-Ming Jou, Pei-Yuan Lee, Chin-Li Lu, Wei-Ren Su, Ming-Long Yeh, and Po-Ting Wu. Treating AO/OTA 44B Lateral Malleolar Fracture in Patients over 5 Years of Age: Periarticular Locking Plate versus Non-Locking Plate. Journal of Orthopaedic Surgery and Research 15, no. 1 (March 20, 2020): 112.

Scientific Literature Review

Reviewed By: Isaac Wilhelm, DPM
Residency Program: St. Mary’s Medical Center  - San Francisco CA

Podiatric Relevance: Ankle fractures are a common injury and become more prevalent in the older population. Using an interfragmentary screw with a nonlocking one-third tubular neutralization plate has been a common method for treating AO/OTA 44B fractures. Surgical treatment of ankle fractures in the older population with osteoporosis can lead to complications. Locking plates have biomechanically performed better in cadaveric osteoporotic bone, but the use of periarticular locking plates for older patients is unclear. Being able to maintain anatomic alignment with stable fixation is critical in promoting good outcomes and prevent risks of post-traumatic arthritis. This study seeks to compare surgical results using periarticular locking plates (PLP) and one-third tubular nonlocking plates (TP) for lateral ankle fractures.

Methods: The authors retrospectively reviewed 72 patients with AO/OTA 44B ankle fractures who were treated with TP or PLP from 2006 through 2017. Thirty-four patients (mean age 63.7 years, 51-80) were treated with PLP and 38 patients (mean age 60.2 years, 51-79) were treated with TP, with a one-year follow-up. The majority of the patients in both groups were female. The authors evaluated radiologic outcomes immediately postoperatively and at the one- year follow-up, reviewing distal fibular length, talar tilt angle > 2 degrees (TTA), fibular shortening, and ankle osteoarthritis grades. Patients’ functional outcomes were obtained using the FAOS and VAS scores. Osteoporosis was determined by previous dual-energy X-ray absorptiometry or by a preoperative lateral radiograph of the calcaneus. 

Results: There were no significant differences in the proportion of osteoporosis, initial ankle OA grade, initial distal fibular length, and initial reduction accuracy between the two groups. All fractures achieved union. The PLP group performed significantly better in the one year FAOS total scores and VAS scores. Comparing radiographic findings immediately postoperatively and at the one year follow-up, the PLP group did significantly better than the TP group with distal fibula shortening (1.1 millimeters versus 1.9 millimeters), TTA > 2 degrees (5.9 degrees versus 26.3 degrees), fibula shortening > 2 millimeters (14.7 percent versus 42 percent), and distal screw loosening (0 percent versus 36 percent). OA grades were significantly higher in the TP group at the one year follow-up.

Conclusions: Overall, this study showed patients treated with a periarticular locking plate for AO/OTA 44B fracture over 50 years of age had better radiographic and functional outcomes at one year follow-up than adults treated with a one-third tubular plate. There were several limitations to this study: it was a retrospective study, osteoporosis was diagnosed by a lateral calcaneal radiograph, follow-up was only one year and long-term postoperative radiographs and functional outcomes were not evaluated. Although locking plates performed better, the cost is much higher than that of a TP. Further studies need to be performed to evaluate the cost-effectiveness. 

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