Patient Reported and Radiographic Outcomes following the Malerba Osteotomy

Abstract

Category: Hindfoot; Other Introduction/Purpose: The Malerba calcaneal osteotomy is a step cut Z-type osteotomy with a lateral wedge resection used to treat hindfoot varus deformity. The osteotomy allows for lateral translation while the wedge resection enables lateral rotation of the calcaneal tuberosity. The technique enables a more powerful correction of hindfoot varus without excessive lateral translation of the calcaneus, which has been shown to cause tarsal tunnel syndrome. Thus far, there have been few published clinical and radiographic outcomes on the Malerba osteotomy. The purpose of this article is to report on patient reported outcome scores (PROMIS), complications, and radiographic improvement in a series of patients treated with this osteotomy. Methods: A prospectively collected foot and ankle registry was queried to retrospectively identify patients who underwent a Malerba osteotomy from February 2016 through January 2022. Patients were included if they were over 18 years of age, underwent a Malerba osteotomy, had preoperative and minimum 1-year postoperative PROMIS scores, and preoperative and postoperative radiographs. 40 patients met the inclusion criteria (average age 54.3 years). PROMIS scores from 6 domains including physical function, pain interference, pain intensity, global physical health, global mental health, and depression were compared preoperatively and postoperatively. Radiographic measures including talonavicular coverage angle (TNCA), calcaneal pitch (CP), and lateral talus-1st metatarsal angle (Meary’s angle) were measured and compared preoperatively and postoperatively. Complications and radiographic union were also recorded. Results: At a mean of 22 months, PROMIS domains including physical function, pain interference, pain intensity, global physical health, and global mental health improved significantly; the depression scale did not significantly change (Table 1). Calcaneal pitch and Meary’s angle significantly improved from 22.9 to 19.1 (p <.001) and 8.2 to 5 (p <.001), respectively. The talonavicular coverage angle did not significantly improve (p=.2). There were no delayed unions or nonunions. There was 1 case of sural neuritis but no instances of postoperative tarsal tunnel syndrome. There were 3 (8%) superficial infections treated nonoperatively and 0 deep infections. 4 patients (10%) required reoperation: 2 for removal of hardware and 2 for conversion to subtalar fusion. Conclusion: The Malerba calcaneal Z-osteotomy is an effective and safe method to treat adult hindfoot varus deformity. In our series, patients demonstrated an improvement in PROMIS and radiographic outcomes with minimal complications. In particular, the rate of neurologic complications was very low with only one case of sural neuritis and no cases of iatrogenic tarsal tunnel syndrome.