Hip Fractures: Current Review of Treatment and Management

Daniel C. Kim, MD, MS; Michael W. Honeycutt, MD; John T. Riehl, MD

Disclosures

Curr Orthop Pract. 2019;30(4):385-394. 

In This Article

Femoral Neck Fractures

Introduction

FN fractures are proximal femoral fractures located in the region between the femoral head and the trochanters. Common risk factors for FN fractures include female gender, white race, tobacco and alcohol use, history of prior fracture, poor health, history of prior falls, and low estrogen levels.[8–10] FN fractures have a bimodal distribution in which the minority are caused by a high-energy mechanism in younger patients, and the majority are caused by low-energy falls in older patients.[11]

Anatomy

The femoral neck-shaft axis forms an angle of 120 to 135 degrees. The FN has an anteversion angle of approximately 10 to 15 degrees in reference to the posterior distal femoral condyles. The blood supply to the femoral neck is tenuous and is primarily served by the medial femoral circumflex artery with contribution also from the lateral femoral circumflex artery and a minor contribution from the artery of the ligamentum teres. The circumflex arteries form an extracapsular ring that gives off the ascending cervical branches. These branches provide retrograde blood flow to the femoral head.[12] One of the treatment challenges of FN fractures is that the FN has relatively inherent poor biological healing potential; most FN fractures are intracapsular and bathed in synovial fluid that inhibits angiogenesis, have a tenuous blood supply, and lack a periosteal layer. Thus healing is endosteal without the ability to form callus.[13]

Classification

Multiple classification systems have been developed for FN fractures, with the most commonly used being the Garden and Pauwels classifications (Figures 1 and 2). The Garden classification is the most frequently used in the literature and is divided into four subtypes based on fracture displacement.[14] Type I fractures are incomplete fractures (including valgus impacted fractures), type II are complete fractures that are nondisplaced, type III are complete and partially displaced, and type IV are complete and fully displaced. However, these subtypes can be difficult to distinguish, and a simplified Garden classification system has been developed that differentiates fractures as nondisplaced (subtypes I and II) versus displaced (subtypes III and IV). Close attention must be paid to the lateral view in femoral neck fractures because many times a fracture may appear valgus impacted (Garden I) on the anteroposterior view but will have posterior displacement on the lateral view (Figure 3). These fractures can have completely different treatments; therefore, diagnosis must be made with careful evaluation of all views. Other classification systems that are not mentioned in this manuscript have been described as well. Pauwels classification is subdivided into three types based on the angle of the fracture line from the horizontal. Type I is less than 30 degrees, type II is 30–50 degrees, and type III is greater than 50 degrees.[15,16] As the angle increases, shearing forces increase, and the risk of fracture displacement and varus collapse increase.[17] Fixed-angle devices for the treatment of higher-grade Pauwels fractures may be of benefit in resisting these forces and to prevent postoperative displacement. The AO/OTA classification is based on a comprehensive classification system that is primarily used for research purposes. The most important treatment and prognostic value of these classification systems is the presence of displaced or nondisplaced fracture fragments because this consideration is critical for determining vascularity and the risk of osteonecrosis. Additionally, FN fractures may be classified based on fracture location within the FN. The FN fracture may be divided into subcapital (directly adjacent to the femoral head), transcervical (mid-neck), and basicervical (low neck) fractures. The significance of location is that subcapital and transcervical fractures are intracapsular fractures, whereas basicervical FN fractures are extracapsular and therefore can be managed similarly to intertrochanteric fractures.

Figure 1.

Garden classification. Type I and II (A and B) are considered "nondisplaced" and type III and IV (C and D) are "displaced" fractures.

Figure 2.

Pauwels classification based on the orientation of the fracture line in the femoral neck. Note increasing verticality of fracture line from type I to type III (A through C). (A) Type I<30 degrees. (B) Type II 30–50 degrees. (C) Type III>50 degrees.

Figure 3.

Femoral neck fracture that appears valgus impacted on anteroposterior view (A); however, it is seen to be displaced on lateral view (B).

Treatment

FN fracture management and surgical treatment are based on a complex algorithm that includes fracture displacement, physiologic age of the patient, bone quality, and presence of an ipsilateral femoral shaft fracture. Early operative intervention has been shown to decrease the mortality risk and the risk of perioperative complications, such as pneumonia and pressure sores.[18] Nonoperative treatment of FN fractures rarely is indicated; it can be considered in non-ambulatory patients with minimal pain and in sick patients with excessive surgical risk; however, even in these instances the risks of nonoperative care over time may be greater than the risk of operative treatment. Operative treatment options include closed reduction percutaneous fixation (CRPF), open reduction internal fixation (ORIF), total hip arthroplasty (THA), and hemiarthroplasty (HA).

Nondisplaced FN fractures (including valgus impacted) commonly are treated with in situ fixation via CRPF using cancellous lag screws. In nondisplaced fracture patterns, the primary surgical goals are to provide stability, prevent fracture displacement, and allow for early mobilization.[19] CRPF with cancellous lag screws provides a stable construct, a minimally invasive approach, and decreased operative time. Typically, three cannulated cancellous screws are placed in an inverted triangle, with the inferior screw along the calcar on the posterior-inferior neck to prevent inferior fracture displacement. Operative pearls while performing CRPF include: ensuring the screw threads are past the fracture site to create a lag effect, maintaining a starting point at or above the level of the lesser trochanter to avoid a ST stress riser, and adding a washer for osteoporotic bone to decrease risk of screw penetration.[6,20]

In displaced fracture patterns in physiologically young patients, ORIF with a sliding hip screw (SHS) is frequently the treatment of choice. Adjunct fixation with an antirotation lag screw or a minifragment locking plate can be considered as well (Figure 4). In displaced fracture patterns, the primary treatment goal is anatomic reduction because malreduction has been shown to lead to poor clinical results, malunion, and increased reoperation rates.[21] If an attempt is made to close reduce a displaced FN fracture, the operating surgeon should have a low threshold for ORIF if an adequate reduction cannot be achieved with closed, indirect methods. SHS constructs are biomechanically superior to cannulated cancellous screws and are indicated in basicervical fractures or vertical fracture patterns (Pauwels 3) in a young patient.[22]

Figure 4.

Displaced femoral neck fracture (A) treated with a fixed-angle sliding hip screw and antirotation screw (B).

In displaced fracture patterns in older individuals, hip arthroplasty is the primary treatment of choice because it allows early mobilization and return to function. The treatment decision for THA versus HA is based on the patient's activity level and the presence of preexisting hip osteoarthritis (OA). Older patients who are active and those with preexisting symptomatic hip OA are ideal candidates for THA. However, there is increased surgical morbidity and higher rates of dislocation with THA.[23] Older patients who are less active are generally well suited for HA. This highlights the multifaceted decision-making process in the treatment of all FN fractures. Optimal treatment involves a complex understanding of patient and fracture-specific characteristics, awareness of potential complications, and technical skill.

Current Controversies

The FAITH (Fixation Alternatives in Treatment of Hip Fractures) trial published in 2017 compared 1079 patients ages 50 or older with both displaced and nondisplaced femoral neck fractures to either cancellous screw fixation versus SHS. This international multicenter trial showed no difference in outcomes in reoperation rate; however, basicervical neck fractures and more vertical fracture patterns trended towards better outcomes with sliding hip screw fixation, consistent with results of prior biomechanical studies.[24] A Cochrane review of over 6,000 patients also found no difference in outcomes between cancellous screws and SHS, although SHS fixation resulted in longer operative times and increased blood loss.[25] This systematic review, however, included 30 different trials of varying quality with heterogeneity in patient selection and inclusion of both displaced and nondisplaced fractures.

Recent observational studies have recommended expedited fixation of hip fractures to decrease associated morbidity and mortality;[18,26,27] however, no large standardized studies currently exist comparing early with delayed surgery. Some inherent bias may be present in these studies, however, as patients with increased acute comorbidities and risk are more often medically delayed from surgery and result in poorer outcomes. Currently, the newest American Academy of Orthopaedic Surgeons (AAOS) guidelines on elderly hip fractures state a moderate recommendation for surgery within 48 hr to improve outcome.[26] A large Canadian multicenter trial is currently in progress, which may further elucidate appropriate timing of surgery.[27]

Newer implant designs may increase stability of fixation and decrease collapse compared to current hardware. A dynamic locking plate (Targon Femoral Neck, B-Braun AG, Melsungen, Germany) with sliding partially threaded cancellous screws locked into a side plate on the proximal femur has shown lower rates of nonunion and collapse over other contemporary fixation devices in a recent British cohort study.[28] The theoretic benefit of this device is rotational advantage over SHS and axial load stability advantage over cancellous screws alone. In addition to new implants, modifications of existing implant use may provide improved biomechanical stability and functional outcomes for patients. In young patients with vertical fracture patterns, studies have shown the use of a medial buttress plate across the anterior inferior femoral neck in addition to cannulated screws or SHS may improve stability[29] and fracture union rates.[30,31]

Controversy still exists regarding hemiarthroplasty versus total hip arthroplasty in some elderly patients with displaced femoral neck fractures.[32] Quality outcomes studies are needed to determine cost efficacy, long-term outcomes, and overall impact on health systems.

In the choice of femoral stem fixation, practices are generally changing from cemented to uncemented press-fit stems.[6] Cemented stems offer more stability in severely osteoporotic bone and have been shown to have fewer reoperation rates than uncemented stems in a large Norwegian study.[33] However, the cemented group in this study had nearly 10 times the mortality risk as well as more than double the perioperative serious complication rate.[33] Recent studies have supported uncemented stems to reduce complications including embolization events, increased surgical time, and intraoperative blood loss.[34–36]

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