ABSTRACT
BACKGROUND: Percutaneous fixation of proximal humeral fractures places the axillary nerve and posterior humeral circumflex artery at risk for injury. Safe operative zones for the axillary nerve are described based on external measurements from anatomic landmarks, but no study to date has incorporated advanced imaging to help guide surgical procedures in the region of the axillary neurovascular bundle (ANVB). We sought to define the location and trajectory of the ANVB in relation to osseous landmarks using magnetic resonance imaging (MRI) measurements. METHODS: Retrospective review of 750 consecutive MRI studies was performed with 55 imaging studies meeting inclusion criteria for patient positioning, image alignment, and quality. Five measurements were performed including the distance from mid-lateral acromion to lateral ANVB, mid-lateral acromion to medial ANVB, greater tuberosity to lateral ANVB, vertical distance between inferior anatomic neck and lateral ANVB, and angle the ANVB crosses the humerus. Height, gender, and age were recorded. Analysis was performed using ANOVA and Pearson correlation tests. RESULTS: The lateral ANVB was below the inferior articular margin of the humeral head by an average of 12.9 ± 3.9 mm and within a 22 mm window. It was an average of 57.4 ± 5.1 mm from the lateral mid-acromion, and 34.7 ± 4.3 mm below the greater tuberosity. The angle formed by the ANVB crossing the humerus averaged 19.5 ± 3.9 degrees upward from medial to lateral. Height and gender directly impacted measurements. CONCLUSIONS: The use of the inferior humeral head articular margin provides a radiographic landmark to aid intraoperative lateral ANVB assessment which may be helpful during percutaneous fracture fixation.
ABSTRACT
INTRODUCTION: Pathologic fractures often contribute to adverse events in metastatic bone disease, and prophylactic fixation offers to mitigate their effects. This study aims to analyze patient selection, complications, and in-hospital costs that are associated with prophylactic fixation compared with traditional acute fixation after completed fracture. MATERIALS AND METHODS: The Nationwide Inpatient Sample database was queried from 2002 to 2014 for patients with major extremity pathologic fractures. Patients were divided by fixation technique (prophylactic or acute) and fracture location (upper or lower extremity). Patient demographics, comorbidities, complications, hospitalization length, and hospital charges were compared between cohorts. Preoperative variables were analyzed for potential confounding, and χ2 tests and Student's t tests were used to compare fixation techniques. RESULTS: Cumulatively, 43,920 patients were identified, with 14,318 and 28,602 undergoing prophylactic and acute fixation, respectively. Lower extremity fractures occurred in 33,582 patients, and 10,333 patients had upper extremity fractures. A higher proportion of prophylactic fixation patients were white ( P = .043), male ( P = .046), age 74 years or younger ( P < .001), and privately insured ( P < .001), with decreased prevalence of obesity ( P = .003) and/or preoperative renal disease ( P = .008). Prophylactic fixation was also associated with decreased peri- and postoperative blood transfusions ( P < .001), anemia ( P < .001), acute renal failure ( P = .010), and in-hospital mortality ( P = .031). Finally, prophylactic fixation had decreased total charges (-$3,405; P = .001), hospitalization length ( P = .004), and extended length of stay (greater than 75th percentile; P = .012). CONCLUSION: Prophylactic fixation of impending pathologic fractures is associated with decreased complications, hospitalization length, and total charges, and should be considered in appropriate patients.
