What is the treatment for an avulsion fracture of the knee?

From the Guidelines

Avulsion knee fractures should be treated with conservative management for small, minimally displaced fractures, while larger or more displaced fractures require surgical fixation to ensure optimal outcomes in terms of morbidity, mortality, and quality of life. An avulsion knee fracture occurs when a tendon or ligament pulls a piece of bone away from the main bone structure, commonly affecting the tibial tuberosity, patella, or femoral attachments of the cruciate ligaments. The treatment approach depends on the size of the bone fragment and the degree of displacement. For small, minimally displaced avulsion fractures (less than 1-2 cm and displaced less than 2-3 mm), conservative treatment is typically recommended, including immobilization with a knee brace or cast for 4-6 weeks, followed by progressive weight-bearing and physical therapy, as suggested by the American College of Radiology 1.

Pain management involves NSAIDs like ibuprofen (400-600 mg three times daily) or naproxen (500 mg twice daily) for 1-2 weeks. Larger fragments or those displaced more than 2-3 mm generally require surgical fixation using screws, sutures, or wires to reattach the bone fragment. After surgery, patients typically wear a brace for 2-4 weeks, followed by 3-6 months of rehabilitation. Physical therapy focuses on restoring range of motion, strengthening the quadriceps and hamstrings, and gradually returning to normal activities. Surgical intervention is particularly important for athletes and active individuals to restore knee stability and function, as emphasized in the context of acute trauma to the knee 1. Complete healing typically takes 6-12 weeks, though return to sports may take 3-6 months depending on the severity of the injury and the patient's progress in rehabilitation.

Key considerations in the treatment of avulsion knee fractures include:

• The size and displacement of the bone fragment
• The patient's activity level and functional goals
• The potential benefits and risks of surgical versus conservative management
• The importance of prompt and accurate diagnosis to facilitate adequate management and prevent potential complications, as highlighted in the evaluation of acute knee injuries 1. In general, the treatment approach should prioritize minimizing morbidity, mortality, and optimizing quality of life, with a focus on restoring knee function and facilitating return to normal activities, as guided by the principles of managing acute traumatic knee injuries 1.

From the Research

Avulsion Knee Fracture

An avulsion knee fracture occurs when a fragment of bone is pulled away from the main mass of bone as a result of physical trauma, often due to a sudden contraction of the muscle or tendon attached to the bone.

Causes and Types

Avulsion fractures can occur in various parts of the knee, including the tibial spine, posterior cruciate ligament, and popliteus tendon. The treatment approach may vary depending on the location and severity of the fracture.

Treatment Options

• Surgical treatment: Open reduction and internal fixation is a common approach for treating avulsion fractures, especially for displaced fractures 2.
• Arthroscopic treatment: This minimally invasive approach can be used for certain types of avulsion fractures, such as tibial eminence avulsion fractures, and may involve suture tensioning techniques to achieve anatomic reduction and maintain appropriate tensioning 3.
• Conservative management: Nonsurgical treatment, including immobilization and physical therapy, may be considered for nondisplaced or minimally displaced fractures.
• Surgical excision: In cases of chronic avulsion fractures, surgical excision of the nonunited bone fragment may be necessary to alleviate symptoms such as knee locking and pain 4.

Postoperative Management

• Immediate postoperative range of motion and muscle-strengthening exercises in a functional brace can help achieve satisfactory results and prevent complications such as knee stiffness and limited range of motion 2.
• Prompt imaging with computed tomography (CT) or magnetic resonance imaging (MRI) can help characterize the degree of injury and guide treatment decisions 4, 5, 6.

Complications

• Residual laxity, knee stiffness, and nonunion or malunion are potential complications of avulsion fractures and their treatment 5.