The femoral neck, connecting the thigh bone’s shaft to the hip joint’s ball, is crucial for hip movement and stability. Fractures in this region are serious injuries that severely impact mobility. The femoral neck system (FNS) is a surgical solution designed to address these fractures, aiming to restore function and facilitate healing through internal fixation.
Understanding the Femoral Neck System
The femoral neck system (FNS) is an internal fixation device for femoral neck fractures. It includes a central compression screw or bolt, an anti-rotation screw, and a small plate. The bolt provides angular stability and carries the load for the femoral head fragment, while the anti-rotation screw enhances rotational stability. These components interconnect, forming a fixed-angle construct that allows for controlled dynamic compression.
The FNS stabilizes specific femoral neck fractures, promoting bone healing and preserving the natural hip joint. It is indicated for various femoral neck fractures, including subcapital, transcervical, and basicervical types, whether displaced or undisplaced. Its design allows for controlled fracture site collapse (up to 20 millimeters) without lateral implant protrusion, reducing soft tissue irritation. This compact design, combined with resistance to varus collapse, maintains stability during healing.
The Surgical Procedure
The FNS surgical procedure is performed under general or regional anesthesia. Patients are positioned supine on a fracture table, enabling precise alignment and imaging during surgery. Proper re-alignment (reduction) of fractured bone fragments is essential for healing.
The surgeon makes a small incision (around 6 centimeters) on the lateral side of the thigh. This incision provides access to the femoral shaft, enabling precise insertion of the FNS components. A single central guide wire guides implant placement. The main components (bolt, anti-rotation screw, and locking screw) are then inserted to fix the fracture.
Post-Surgical Recovery
Recovery following FNS surgery begins immediately in the hospital, where patients stay for one to two days. Pain is managed with medication to facilitate early mobilization. Early movement is encouraged, with many patients beginning gentle range-of-motion exercises and assisted walking with a walker or crutches within 24 to 48 hours after surgery.
Physical therapy is a part of the rehabilitation process, focusing on regaining strength, improving balance, and retraining gait. Over the following weeks and months, therapy progresses to more intensive muscle-strengthening exercises. While individual recovery times vary, most patients can expect the bone to heal within three to four months. However, regaining pre-injury range of motion and strength can take up to 12 months, and consistent adherence to rehabilitation protocols is important for achieving optimal results.
Weight-bearing progression is guided by the surgeon and physical therapist. Younger patients may initially have restricted weight-bearing, which is reassessed around six weeks post-surgery. Elderly patients, however, may be encouraged to bear weight as tolerated with walking aids from the day after surgery to promote early independence. Follow-up appointments, including wound checks at 10 to 14 days and X-rays at two weeks, six weeks, and three months, are scheduled to monitor healing and implant position.
Choosing the Right Approach
The femoral neck system is one of several surgical options for treating femoral neck fractures. Other common methods include the use of multiple cannulated screws, hemiarthroplasty (partial hip replacement), or total hip arthroplasty (total hip replacement). The selection of treatment depends on several factors.
A surgeon considers the patient’s age, the specific type and displacement of the fracture, and the quality of their bone, particularly in cases of osteoporosis. The patient’s pre-injury activity level and overall health also influence the decision. The FNS is often favored for its ability to preserve the native hip joint, which is a significant advantage, especially for younger or more active individuals with certain fracture patterns. This approach aims to provide stable fixation while allowing for controlled compression at the fracture site, promoting healing without the need for joint replacement in appropriate cases.