Extensor Retinaculum Syndrome of the Ankle: An Adult Case Series.

Background: Extensor retinaculum syndrome (ERS) is a relatively rarely diagnosed compartment syndrome-like entity caused by elevated pressures in the tissues deep to the superior extensor retinaculum (SER). ERS is identified as out-of-proportion anterior ankle pain, pain with passive toe plantarflexion, elevated SER pressures (>40 mm Hg), and ultimately toe extension weakness and first web space numbness. Although previously described in a pediatric population, this case series is the first to our knowledge in an adult population. Methods: Seven nonconsecutive cases over 18 years from 2 surgeons are reported who underwent complete SER release for ERS either through the direct lateral approach to the fibula or the anterolateral approach to the distal tibia. All were associated with traumatic injuries including 3 bimalleolar ankle fractures, 3 tibial pilon fractures, and 1 distal tibial/fibular shaft fracture. All patients developed writhing anterior ankle pain worsened with passive toe plantarflexion. SER compartment pressures ranged from 50 to >135 mm Hg. Five cases displayed decreased first web space sensation. Results: The diminished or absent first web space sensation uniformly improved post-release. Complications included 1 patient with complex regional pain syndrome type 1, 1 patient required hardware removal, and 2 had persistent but improved first web space sensation changes. Conclusion: Clinical suspicion for possible ERS should arise after distal tibial/fibular fractures when the excruciating pain localizes to the ankle instead of the classic anterior leg muscle bellies. If pain is worsened with passive toe plantarflexion, this diagnosis should be considered. Recommended treatment involves complete release of the SER anywhere on the anterior surface between the tibia and fibula depending on the approach needed for fixation of the associated fracture. Level of Evidence: Level IV, case series.

Predicting Prolonged Length of Hospital Stay and Identifying Risk Factors Following Total Ankle Arthroplasty: A Supervised Machine Learning Methodology.

Ankle osteoarthritis (OA) is a debilitating condition that arises as a result of trauma or injury to the ankle and often progresses to chronic pain and loss of function that may require surgical intervention. Total ankle arthroplasty (TAA) has emerged as a means of operative treatment for end-stage ankle OA. Increased hospital length of stay (LOS) is a common adverse postoperative outcome that increases both the complications and cost of care associated with arthroplasty procedures. The purpose of this study was to employ four machine learning (ML) algorithms to predict LOS in patients undergoing TAA using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. The ACS-NSQIP database was queried to identify adult patients undergoing elective TAA from 2008 to 2018. Four supervised ML classification algorithms were utilized and tasked with predicting increased hospital length of stay (LOS). Among these variables, female sex, ASA Class III, preoperative sodium, preoperative hematocrit, diabetes, preoperative creatinine, other arthritis, BMI, preoperative WBC, and Hispanic ethnicity carried the highest importance across predictions generated by 4 independent ML algorithms. Predictions generated by these algorithms were made with an average AUC of 0.7257, as well as an average accuracy of 73.98% and an average sensitivity and specificity of 48.47% and 79.38%, respectively. These findings may be useful for guiding decision-making within the perioperative period and may serve to identify patients at increased risk for a prolonged LOS.