Femoral Neck Fractures

Transcription

1 Femoral Neck Fractures Michael Monge, Harvard Medical School

2 Agenda Epidemiology Normal anatomy of the femur Garden classifications Patients Summary 1

3 Epidemiology 1 250,000 yearly hip fractures in the US This is expected to double by % occur to those over the age of fifty 25% mortality at one year Of patients who survive to six months, 60% will regain their pre-fracture walking ability and 50% will regain their pre-fracture activities of daily living 2

4 Epidemiology 2 Falls account for 90% hip fractures for those over fifty years of age 15% of falls result in hip fracture The most common cause in young patients is high energy trauma Pathologic fracture may occur at any age ex. metastasis, hyperparathyroidism, osteogenesis imperfecta, steroids, Pagets disease, infection 3

5 Epidemiology 3 Risk doubles every decade after fifty Risk factors include osteoporosis, female gender, age, excessive caffeine or alcohol consumption, smoking, dementia, visual impairment, physical inactivity, arthritis, certain psychotropic medications, low BMI, and residence in an institution 4

6 Femoral Anatomy 1 An imaginary line can be drawn between the Greater and Lesser Trochanter called the Intertrochanteric Line This is important for classification of fractures 5

7 Femoral Anatomy 2 Lines correlating torque and mathematical expressions to endure loads follow closely to the trabecular matrix 6

8 Femoral Anatomy 3 Trabeculae are arranged in a matrix that allows maximal dissipation of vertical and horizontal forces This network is compromised in the elderly due to osteoporosis 7

9 Femoral Anatomy 4 A fracture proximal to the Intertrochanteric line is considered intraarticular and distal is extraarticular Important with respect to vascular complications 8

10 Types of hip fractures Acetabulum Greater Trochanter Head Lesser Trochanter 1. Subcapital fracture 2. Intertrochanteric Fracture 3. Subtrochanteric fracture 9 Images from BIDMC Hospital

11 Femoral Vessels Three vessels feed the femoral head The Medial is considered the most important Individual variation and/or anastomosis still exists between them all 1. Medial femoral circumflex artery 2. Lateral femoral circumflex artery 3. Artery of Ligamentum Teres 10

12 RT Femoral Angiogram 1. Medial Femoral Circumflex Artery 2. Ascending LFCA 3. Transverse LFCA 4. Descending LFCA Femoral Artery Lateral Femoral Circumflex Artery Superficial Femoral Artery Profunda Femoris 11

13 Role of imaging Evaluation for chronic or sub acute hip pain based on physical exam, history Trochanteric bursitis, OA, Lumbar radiculopathy, Meralgia paresthesia, Osteonecrosis, hip fracture Plain radiograph (AP, AP with internal rotation of about 15 degrees, Lateral) MRI, Bone scan, CT Prognosis, planning of medical and surgical intervention 12

14 Garden Classifications I III II IV Studies indicate that Radiologist agree in diagnosing garden types only 22% of the time The important distinction is I/II versus II/IV because risk of avascular necrosis jumps from 7% to 37% respectively This distinction is clear 13 McGraw Hill

15 Garden Type I/II Type I Incomplete fracture No displacement Type II Complete fracture No displacement Internal rotation causes hip pain Sometimes able bear weight Ecchymoses Stinchfield test 14

16 Garden Type 1 Fracture Incomplete femoral neck fracture Uptake in femoral neck on bone scan 15 Images from BIDMC Hospital

17 Garden Type II Fracture T1 MRI complete femoral neck fracture 16

18 Garden Type III/IV Garden III Complete Partial displacement Garden IV Complete Total displacement Unable to bear weight Groin pain External rotation Short limb 17

19 Garden Type III Fracture T1 MRI complete femoral neck fracture with partial displacement 18

20 Patient 1 79 year old female with history of CVA in 2002, aphasia, dementia, and COPD Admitted for a fall in her kitchen Unable to acquire a verbal history due to her aphasia Found by her son who was visiting 19

21 P1 Hip Radiograph 1 Type IV 20 Images from BIDMC Hospital

22 P1 Hip Radiograph 2 Femoral head replacement 21 Images from BIDMC Hospital

23 Patient 2 35 year old male s/p motorcycle accident High energy mechanism of trauma Multiple soft tissue injuries and fractures 22

24 P2 Radiograph 1 Sacroiliac fracture and widened pubic symphysis Images from BIDMC Hospital Type IV fracture s/p external reduction 23

25 P2 CT 1 Superomedial pubic ramus fracture Femoral neck fracture 24 Images from BIDMC Hospital

26 P2 CT 2 Sacroiliac joint fracture 25 Images from BIDMC Hospital

27 P2 CT 3 Kidney laceration 26 Images from BIDMC Hospital

28 P2 CT 4 Subcutaneous emphysema Images from BIDMC Hospital Inferior pubic ramus fracture 27

29 Michael Monge, HMS IV P2 Radiograph 2 Internal fixation with screw 28 Images from BIDMC Hospital

30 Summary Femoral neck fractures have a high associated mortality and morbidity Falls are the major cause in elderly and high energy trauma in younger patients Radiological assessment is critical for prompt surgical and medical intervention 29

31 Acknowledgements Thanks to Dr. Gillian Lieberman and Pamela Lepkowski for their help and inspiration Cristina Cavazos, MD for her help with patient cases and images Thanks for all the help from the Radiology service and my classmates! 30

32 References Zuckerman JD. Hip Fracture. NEJM 1996; Guyton JL. Fracture of hip, acetabulum, and pelvis. Campbell s Operative Orthopaedics Fox KM, Magaziner J, Hebel JR, et el. Intertrochanteric versus femoral neck fractures: differential characteristics, treatments, and sequelae. J Gerontol A Biol Sci 1999;54:M Hernandez-Avila M, Colditz GA, Stampfer MJ, et al. Caffeine, moderate alcohol intake, and risk of fractures of the hip and forearm in middle-aged women. Am J Clin Nutr 1991;54: McGrory BJ. Stinchfield resisted hip flexion test. Hosp Physician 1999;35(9):41-2 Koval KJ, Zuckerman JD. Hip fractures I. Overview and evaluation and treatment of femoral-neck fractures. J Am Acad Orthop Surg 1994;2: Cummings SR, Nevitt MC, Browner WS, et al. Risk factors for hip fracture in wh ite women. Study of Osteo-porotic Fractures Research Group. NEJM 1995; 332: