Knee plates are orthopedic implants used in surgical procedures to stabilize bone fragments. They support the skeletal structure, aiding bone healing. These implants maintain the alignment of fractured bones, allowing them to mend properly. They serve as internal fixation devices, holding bones in place.
Why Knee Plates Are Used
Knee plates are commonly used for complex fractures around the knee joint, including the distal femur, patella, and tibial plateau. For tibial plateau fractures, where the top of the shinbone breaks, plates and screws reassemble bone fragments and hold them in proper alignment. This stabilization allows the knee to heal correctly, preventing dislocation of bone fragments and minimizing the risk of limb deformity.
Distal femur fractures, occurring just above the knee joint, often require plates and screws for stable fixation, particularly in complex or comminuted fractures. These fractures can cause significant pain and limit knee function if not properly treated. Knee plates are also used in corrective osteotomies, such as high tibial osteotomy (HTO), a procedure that involves cutting and reshaping the tibia or femur to relieve pressure on a damaged knee joint. HTO is performed to correct varus (bow-legged) or valgus (knock-kneed) deformities and to manage early-stage osteoarthritis by realigning the weight-bearing axis and redistributing forces across the joint.
Different Types of Knee Plates
Knee plates come in various designs, each suited for specific fracture patterns and bone characteristics. Locking plates feature threaded screw holes that securely fasten the screw head to the plate, creating a fixed-angle construct. This design provides angular stability, especially beneficial for fractures in areas with poor bone quality, such as osteoporotic bone, as it minimizes the risk of screws pulling out. Unlike non-locking plates, which rely on compression between the plate and bone for stability, locking plates do not require tight contact with the bone, preserving the periosteal blood supply important for bone healing.
Non-locking plates, also known as conventional plates, achieve stability through frictional compression between the plate and the bone. While effective for straightforward fractures in healthy bone, their stability is more dependent on bone quality and precise anatomical reduction. Anatomical plates are pre-contoured to match the bone’s specific shape, ensuring a precise fit and optimal alignment. These pre-shaped plates aid in indirectly reducing fracture fragments and maintaining the biological microenvironment for healing.
Common materials for knee plates include stainless steel and titanium alloys, chosen for their biocompatibility, strength, and corrosion resistance within the body. Titanium alloys are lighter and have an elastic nature that more closely matches bone, which is advantageous for load-sharing implants.
The Surgical Process and Initial Recovery
Knee plate surgery begins with anesthesia (general or regional), ensuring the patient is comfortable and pain-free during the procedure. An incision is made to expose the fractured bone, allowing the surgeon to realign the bone fragments, a process known as open reduction. Once the bone fragments are correctly positioned, the knee plate is secured to the bone using screws, holding the fracture in place while it heals. The surgical wound is then closed with stitches or staples, and a drain may be inserted to remove any excess fluid.
In the immediate post-operative period, pain management is a primary focus, often involving medications such as non-steroidal anti-inflammatory drugs (NSAIDs) and, if necessary, opioids. Local anesthetics and nerve blocks may also be used to provide targeted pain relief. Patients are encouraged to begin early mobility, often within 24 hours of surgery, with physical therapist assistance. This early movement, including gentle ankle pumps and knee bends, helps to reduce swelling, improve circulation, and prevent stiffness. Weight-bearing restrictions are common and depend on the fracture type and stability, with many patients initially using crutches or a walker.
Life After Knee Plate Surgery
Life after knee plate surgery involves a structured rehabilitation process to restore full function and mobility. Physical therapy begins soon after surgery, focusing on exercises that improve range of motion, strengthen muscles around the knee, and enhance balance. These exercises are progressively challenging, moving from simple movements to resistance training and balance exercises, tailored to the individual’s progress. Full recovery can take several months, with many patients feeling significantly stronger and steadier around six weeks post-surgery, and nearing full recovery by three months.
Activity modifications are necessary during the healing period, with high-impact activities like running often discouraged to protect the implant and promote long-term durability. Low-impact activities such as walking, swimming, and cycling are recommended to maintain joint flexibility and muscle strength. Regular follow-up appointments with the surgeon monitor bone healing and the implant’s stability, typically continuing for at least the first year after surgery. Knee plates are often designed to remain permanently, as their removal is a separate surgical procedure that carries its own risks. However, removal may be considered if the plate causes persistent pain, discomfort due to prominence under the skin, infection, or other complications like non-union of the bone.