How do I use a plate for a femoral neck fracture?
Intracapsular fractures of the femoral neck are more common in older patients and occur less frequently in younger populations because of the bone quality. If not properly treated, femoral neck fractures can lead to disability and, in severe cases, death. There are many strategies available for the treatment of femoral neck fractures, and the choice of treatment option depends on the patient’s age, mobility, medical comorbidities, and other relevant conditions. Plate fixation techniques for femoral neck fractures have continued to advance in recent years, and Anthony et al. provide a detailed description of the indications for femoral neck fractures and the choice of plate type in the JOT supplement.
There are many strategies for the treatment of femoral neck fractures, including closed reduction internal fixation (CRIF), incisional reduction internal fixation (ORIF), hemi hip replacement, and total hip replacement. The choice of treatment option depends on the patient’s age, function, medical comorbidities, bone quality, and fracture characteristics. Treatment of femoral neck fractures with a plate can have a good outcome in patients with the right indication.
Indications for surgery
Indications for internal plate fixation of femoral neck fractures include patients younger than 65 years of age, or older patients with high functional requirements, or older patients without displacement or minor exostosis insertion of the femoral neck fracture. The goals of femoral neck fracture treatment are to obtain good function, preserve the joint, and prevent medical complications.
Surgical Approach Selection
Plate fixation of femoral neck fractures requires adequate exposure of the proximal femur and, in some cases, also of the fractured femoral neck. Early anatomic reduction of the femoral neck fracture is important for fracture healing and long-term hip preservation, as patients with poor reduction are more likely to have healing complications and undergo reoperation. Although satisfactory results can usually be obtained with closed reduction of the femoral neck fracture, if the femoral neck is not satisfactorily reduced, an incisional reduction should be considered to obtain a satisfactory anatomic reduction.
The direct anterior approach, the anterolateral approach, and the lateral approach are the conventional approaches for proximal femoral exposure. The anterolateral and lateral approaches provide adequate exposure of the femoral neck to facilitate fracture repositioning and placement of the lateral femoral plate. If the anatomic repositioning of the fracture cannot be accomplished with the above two approaches, an anterior approach may be added to facilitate exposure of the femoral neck. Some authors suggest that the surgical approach be chosen based on the location of the femoral neck fracture.
Transcervical or distal femoral neck fractures can be treated with a single lateral approach, while transcervical or proximal femoral neck fractures can be treated with a dual surgical approach. It is important to note that these approaches only expose the anterior aspect of the femoral neck and that the fracture cannot be determined by the flatness of the anterior femoral neck fracture line alone during surgery.
Internal fixation
Internal fixation plates for proximal femoral neck fractures include SHS, proximal femoral locking plates, power locking plates, and angular plates.
SHS Plates
SHS plates are angularly fixed, power-compression fixation devices suitable for the treatment of nondisplaced, embedded, and displaced femoral neck fractures (Figure 1). These devices can provide better mechanical stability against shear forces than tension screws. Careful preoperative measurement of the neck stem angle is required to assist in the proper intraoperative plate selection. The optimal position of the power hip screw is with the screw centered anteroposteriorly and laterally and the plate centered on the femoral stem in the lateral view. In some cases, the addition of an anti-rotation screw above the hip screw may be considered. If SHS and retrograde intramedullary nailing are used in combination to treat a combined femoral neck and stem fracture, attention should be paid to the position of the screws, either with the SHS screw tangential to the end of the intramedullary nail to avoid the intramedullary nail or with the SHS screw driven into the locking hole in the end of the intramedullary nail. A temporary anti-rotation screw can be added before the SHS head nail is placed to reduce the chance of fracture loss.
Figure 1: Anteroposterior and lateral X-rays showing SHS plate combined with anti-rotation screw for femoral neck fracture
Proximal femoral locking plate
Theoretically, an internal fixation device of a certain length, such as a proximal femoral locking plate, may reduce the likelihood of shortening of the femoral neck in SHS, improve functional prognosis, reduce the revision rate, and provide adequate mechanical stability. Cadaveric studies have shown that the best mechanical strength can be obtained with locking plate fixation for femoral neck fractures. However, the failure rate of femoral neck fractures treated with locking plates has been found to be extremely high during clinical use, which may be related to the greater stiffness of the locking plates, which hinders the favorable conditions associated with promoting fracture healing, such as the presence of micromotion and compression at the fracture end. The prolonged non-healing of the fracture eventually leads to the breakage of the internal fixation. Based on the current clinical results, proximal femoral locking plates should not be a routine option for the treatment of femoral neck fractures. A proximal femoral locking plate may be considered in cases where a fracture of the femoral stem is combined with a fracture of the femoral neck that cannot be treated with an intramedullary nail (Figure 2).
Figure 2: Proximal femoral fracture combined with a femoral neck fracture treated with a proximal femoral locking plate.
Angled plates
The angular plate type is commonly used for fixation of non-union or malunion osteotomies of the femoral neck fracture, and there is no research data to support the routine use of angular plates in cases of femoral neck fractures. A small number of clinical studies have found that 130-degree angled plates from AO are more effective in the treatment of femoral neck fractures; however, it is believed that the outcome depends more on the surgeon’s experience with the plate than on the internal fixation itself.
Proximal femoral power locking plate
The proximal femoral power locking plate is a new device (Fig. 3, e.g., Targon FN) that has shown good advantages in the treatment of femoral neck fractures. The plate is designed to incorporate the advantages of tension screws and SHS to provide better rotational stability, control collapse of the femoral head, and prevent screw cutout. Clinical follow-up results found that the proximal femoral neck locking plate can achieve similar results as SHS and tension screws, but with less femoral head collapse than SHS and lower rates of fracture non-union and revision than tension screws. More studies are needed to confirm its clinical efficacy in the future.
Figure 3: Recent Emerging Proximal Femoral Power Locking Plates
Summary
Fractures of the femoral neck can lead to more serious consequences. Treatment of femoral neck fractures with open or closed reduction internal fixation using plates can have good results in some patients who are selected appropriately. The goals of femoral neck fracture treatment are to restore the patient’s function after treatment, to preserve the patient’s hip joint, and to prevent medical complications. To reduce postoperative complications, careful preoperative evaluation and thorough planning of the patient is required. Appropriate surgical access and selection of internal fixation devices are of great importance in obtaining the best possible outcome.