Femoral neck fractures Published: July 2013 Revised: 2018 Reviewer: Friedrich Baumgaertel

Learning objectives Classify femoral neck fractures Outline indications for internal fixation versus arthroplasty Describe reduction and surgical techniques for internal fixation Describe potential complications after treatment of femoral neck fractures Teaching points: Timing of intervention, rationale for arthrotomy, and patient considerations.

Incidence and causes Elderly: Majority (most commonly in the eighth decade) Low-energy trauma; simple falls Osteoporosis Women 1.7 million hip fractures annually worldwide Femoral neck = 53% of all proximal femoral fractures Young: Very rare High-energy trauma Men

Geriatric patients are problem patients Disturbed physiological equilibrium Reduced cognitive functions Reduced mobility Disturbed microcirculation Substance abuse (eg, alcohol, antidepressants) Pathological bone stock, especially osteoporosis High morbidity

Problem patients High complication rates with femoral neck fractures: Nonunion Avascular necrosis (AVN) Fixation failure/loss of reduction All are related to vascularity

Vascular anatomy Ascending cervical arteries (retinacular arteries) Artery of the ligamentum teres Intraosseous cervical vessels Blood supply of the femoral head is at risk of damage Femoral neck fracture

AO/OTA Fracture and Dislocation Classification AO/OTA Fracture and Dislocation Classification (31B) B1—Subcapital, with slight displacement B2—Transcervical B3—Basicervical, unimpacted, displaced Classification implies vascularity

AO/OTA Fracture and Dislocation Classification 31B1.1 Subcapital, valgus impacted 31B1.1 Perfusion potential is good

AO/OTA Fracture and Dislocation Classification 31B2.1 Transcervical 31B2.1 or basicervical 31B3 displacement Perfusion potential is good 31B3

AO/OTA Fracture and Dislocation Classification 31B1.3 Subcapital displaced, no impaction 31B1.3 Perfusion potential is poor

Garden Classification I II III IV Displaced or nondisplaced

What determines the outcome? Perfusion of the femoral head correlates with stability Undisplaced, stable versus Displaced, unstable

Diagnosis X-rays: AP and lateral views Postfall hip pain in the elderly patient with normal x-rays  wait and see or order computed tomography (CT) or magnetic resonance imaging (MRI)? 15 days later 79-year-old woman, simple fall

Diagnostic imaging Hip pain after a fall with normal x-rays MRI or CT Bone scan?

Timing of surgery In young patients Reduction and fixation as quickly as possible: In young patients In medically stable, elderly patients Surgical urgency: Trend toward better outcome with earlier surgery

Choice of treatment Internal fixation: Arthroplasty: Cannulated cancellous screws Screw and side plate (dynamic hip screw [DHS]) Arthroplasty: Hemiarthroplasty (HA) (unipolar/bipolar) Total hip arthroplasty (THA)

Undisplaced fractures Internal fixation: Prevent secondary displacement Safe and simple (only 10–15% failure rate) Cannulated screws  implant of choice

Impacted Valgus Stable Fix without reduction Prevent secondary displacement

Displaced fracture In unstable, displaced fractures the choice of treatment depends mainly on the general and biological conditions Can the patient tolerate failure? One chance Internal fixation Arthroplasty

Internal fixation Internal fixation is the treatment of choice for patients with high functional demands and good bone stock Patients less than 65 years old and do not have a chronic illness Early reduction and internal fixation  Decrease AVN of the femoral head

Internal fixation Internal fixation is quicker and often simpler than arthroplasty Operative time Blood loss Risk of mortality

Fracture reduction Reduction of the fracture: Closed reduction with gentle traction/internal rotation Open reduction, if required

Anterolateral approach Fracture reduction In cases that are not reduced easily: Avoid repeated and vigorous attempts at closed reduction Open reduction is indicated Anterolateral approach Anterior capsulotomy In cases that are not reduced easily, repeated and vigorous attempt must be avoided and open reduction through the anterolateral approach is indicated.

Implants—cannulated screws Usually adequate for most femoral neck fractures Insertion of three screws: In inverted triangular configuration Parallel to each other to allow compression

Screw placement Must be placed at or above the lesser trochanter to prevent stress risers References: Oakey JW, Stover MD, Summers HD et al. Does screw configuration affect subtrochanteric fracture after femoral neck fixation? Clin Orthop Relat Res. 2006 Feb;443:302–306.

Screw placement Must be placed at or above the lesser trochanter to prevent stress risers Screw placement below the lesser trochanter: Increased risk of subtrochanteric fracture

Four screws Biomechanical data shows four screws are more stable in fractures with posterior comminution Consider DHS in cases with posterior comminution While biomechanically there is some benefit to a fourth screw placed for posterior comminution. Those with severe posterior comminution generally are better treated with a dynamic hip screw (DHS).

Implants—dynamic hip screw Usually used in fractures of the femoral neck base Helpful in fractures with severe osteoporosis and posterior comminution

Implants—dynamic hip screw A 2-hole plate is sufficient for shaft fixation The tip-apex distance rule ensures adequate fixation of the screw thread in head Insertion of a derotation screw: Prevent rotation of the femoral head Achieve good buttressing at the fracture site

Dynamic hip screw versus screws If a DHS is used: Increased AVN rate Increased nonunion rate High AVN incidence if screw is positioned superolaterally in the neck Implant of choice for internal fixation? No differences between screws and DHS References: Linde F, Andersen E, Hvass I, et al. Avascular femoral head necrosis following fracture fixation. Injury. 1986 May;17(3):159–163. Madsen F, Linde F, Andersen E, et al. Fixation of displaced femoral neck fractures. A comparison between sliding screw plate and four cancellous bone screws. Acta Orthop Scand. 1987 Jun;58(3):212–216. Vail TP, Urbaniak JR. Outcomes in surgical treatment of femoral neck fracture: analysis of failures secondary to osteonecrosis. J South Orthop Assoc. 1995 Summer;4(2):83–90. Parker MJ, Blundell C. Choice of implant for internal fixation of femoral neck fractures. Meta-analysis of 25 randomised trials including 4,925 patients. Acta Orthop Scand. 1998 Apr;69(2):138–143.

Arthroplasty Indications: Primary: Secondary: Elderly patients ( > 75 years) Low functional demands Chronic illness Severe osteoporosis Secondary: Failed fixation Nonunion

Arthroplasty Advantages: Allows immediate weight bearing Eliminate AVN and nonunion Significantly reduces the incidence of reoperation References: Bhandari M, Devereaux PJ, Swiontkowski MF, et al. Internal fixation compared with arthroplasty for displaced fractures of the femoral neck. A meta-analysis. J Bone Joint Surg Am. 2003 Sep;85(9):1673–1681. Keating JF, Grant A, Masson M, et al. Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty. Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am. 2006 Feb;88(2):249–260.

Arthroplasty Disadvantages: Greater infection rates More blood loss and longer operative time Possible increase in early mortality rates References: Bhandari M, Devereaux PJ, Swiontkowski MF et al. Internal fixation compared with arthroplasty for displaced fractures of the femoral neck. A meta-analysis. J Bone Joint Surg Am. 2003 Sep;85-A(9):1673-81. Keating JF, Grant A, Masson M et al. Randomized comparison of reduction and fixation, bipolar hemiarthroplasty, and total hip arthroplasty. Treatment of displaced intracapsular hip fractures in healthy older patients. J Bone Joint Surg Am. 2006 Feb;88(2):249-60.

Hemiarthroplasty versus total hip arthroplasty Less pain with THA Greater mobility with THA Lower revision rate with THA More frequent dislocation in early stage with THA THA : Patients with preexisting hip disease Active, healthy patients without preexisting hip disease References: Acute intracapsular hip fractures. Hemiarthroplasty (HA) versus total hip arthroplasty (THA). Orthopedic Trauma Directions. 2005;3(5):1–8. [https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-2005-919128]

Internal fixation versus arthroplasty—metaanalysis Internal fixation versus arthroplasty for displaced fractures of the femoral neck: Early mortality: a trend toward increased mortality 4 months after arthroplasty Revision surgery: significantly reduced risk of revision surgery with arthroplasty Infection: significantly increased risk of infection with arthroplasty References: Bhandari M, Devereaux PJ, Swiontkowski MF et al. Internal fixation compared with arthroplasty for displaced fractures of the femoral neck. A meta-analysis. J Bone Joint Surg Am. 2003 Sep;85-A(9):1673-81.

Factors that influence decision making Patient factors: Osteoporosis Medical comorbidities Preinjury functional status Fracture factors: Displacement Comminution Some factors can not be controlled by surgeons

Osteoporosis The most common reason of failure following fixation Bone cut-out rather than implant failure References: Gardner MJ, Lorich DG, Lane JM. Osteoporotic femoral neck fractures: management and current controversies. Instr Course Lect. 2004;53:427–439. Review. Bray TJ. Femoral neck fracture fixation. Clinical decision making. Clin Orthop Relat Res. 1997 Jun(339):20–31. Review.

Medical comorbidity Diabetes, heart disease, cerebral dysfunction, visual abnormality, prior skeletal injury, depression Elderly patients with a displaced femoral neck fracture and multiple comorbidities At higher risk for outcome failure References: Richmond J, Aharonoff GB, Zuckerman JD et al. Mortality risk after hip fracture. Geriatric Hip Fracture Research Group, Department of Orthopaedic Surgery, Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA. Richmond J, Aharonoff GB, Zuckerman JD, et al. Mortality risk after hip fracture. J Orthop Trauma. 2003 Jan;17(1):53–56. Zuckerman JD, Skovron ML, Koval KJ, et al. Postoperative complications and mortality associated with operative delay in older patients who have a fracture of the hip. J Bone Joint Surg Am. 1995 Oct;77(10):1551–1556.

Preinjury functional status and age Patients 65 years old or younger  urgent anatomical reduction/internal fixation Patients older than 75 years  arthroplasty Patients between 65 and 75 years (gray zone) Decision must be based individually on patient factors Physiological age is a better criterion than chronological age in deciding on HA References: Gardner MJ, Lorich DG, Lane JM. Osteoporotic femoral neck fractures: management and current controversies. Instr Course Lect. 2004;53:427–439. Review. Bray TJ. Femoral neck fracture fixation. Clinical decision making. Clin Orthop Relat Res. 1997 Jun(339):20–31. Review.

Displacement and comminution Undisplaced fractures: Fixation candidate: to prevent secondary displacement Displaced fractures or posterior comminution: Patients younger than 65 years  urgent reduction/internal fixation Elderly patients  arthroplasty

Decision-making criteria Fixation versus hip replacement: Age and fitness of the patient Level of activity Comorbid diseases (including hip osteoarthritis) Displacement of the fracture Quality of bone Time since injury Available implants Surgeon’s experience

Take-home messages Valgus impacted heads require fixation in situ Displaced heads have higher rate of complications Closed reduction achieved in most cases Fixation options are three screws or DHS plus antirotation screw Arthroplasty is indicated in the elderly when fracture is displaced