Knee Fractures

How Knee Fractures Occur

Knee fractures can happen in many ways, from lower-energy incidents to high-force trauma.

Impact or Direct Blow

A fall directly onto the front of the knee may cause a patella fracture, especially if the knee is flexed at the time of impact. This mechanism is common during slips, stair falls, or contact sports.

Twisting or Rotational Forces

Twisting the leg while bearing weight can lead to fractures of the tibial plateau or the outer structures of the knee. These injuries may involve the cartilage surfaces or supporting ligaments.

High-Energy Trauma

Motor vehicle accidents or significant falls can cause complex fractures of the tibial plateau or distal femur. These often require a structured assessment, additional imaging, and consideration of overall limb alignment.

Stress or Insufficiency Fractures

Although less common around the knee, repetitive load or underlying bone health concerns may lead to small fractures in areas such as the tibial plateau. These may present gradually rather than suddenly.

Understanding the mechanism helps guide which areas of the knee require careful assessment.

Classification of Knee Fractures

Fractures are often described based on location, pattern, and whether they affect the joint surface. These details guide treatment choices.

Displaced vs Non-Displaced

A displaced fracture occurs when bone fragments shift out of position. These may cause alignment problems or joint surface irregularities. Non-displaced fractures maintain bone alignment and may be suitable for non-surgical management.

Intra-Articular vs Extra-Articular

Intra-articular fractures extend into the knee joint surface. These require precise assessment, as the cartilage and joint congruency may be affected. Extra-articular fractures occur outside the joint and may have different stability considerations.

Comminuted Fractures

These involve multiple small pieces of bone. They often result from higher-force trauma and may require surgical stabilisation to restore alignment.

Depression or Split Patterns (Common in Tibial Plateau Fractures)

A depression fracture involves the joint surface being pushed downward. A split pattern involves a crack that separates part of the tibial plateau. Some fractures combine both patterns.

These classifications help determine whether alignment can be maintained with bracing or whether surgical intervention may support safer healing.

Effects of Knee Fractures on Joint Function

Knee fractures can influence movement, stability, and load transfer in several ways.

Joint Stability

If the fracture affects an area where ligaments attach, such as the fibular head or tibial spine, stability may be impacted. This can create feelings of knee giving way or uneven control during movement.

Weight-Bearing and Distribution of Load

Fractures involving the tibial plateau or distal femur may alter how load passes through the knee. Small changes can influence comfort and may contribute to symptoms such as early fatigue or stiffness.

Knee Extension and Flexion Strength

Patella fractures may interfere with the quadriceps mechanism, making it difficult to straighten the knee fully. This affects everyday tasks such as standing, walking, or climbing stairs.

Surrounding Soft Tissues

Muscles, tendons, and the joint capsule may also be affected by swelling, bruising, or associated injury. These factors can temporarily limit movement, even after the bone begins to heal.

Understanding these effects helps set realistic expectations for the phases of recovery.

Recognising Symptoms After a Possible Knee Fracture

Not all knee fracture symptoms are obvious, and some may resemble soft-tissue injuries.

You may notice:

• Sharp pain immediately after the incident
• Increasing discomfort with weight-bearing
• Swelling that develops quickly or continues to worsen
• Bruising around the front, inner, or outer knee
• Difficulty bending or straightening the leg
• Visible changes in knee shape or alignment
• Sensitivity when touching the kneecap or joint line
• A sensation of instability, heaviness, or weakness

If these symptoms follow a fall or twisting injury, it may be helpful to arrange a medical review.

How Knee Fractures Are Diagnosed

A thorough knee fracture diagnosis helps identify which structures are affected and guides the next steps.

Physical Examination

Your clinician may assess swelling, range of motion, strength, and areas of localised tenderness. They may also check for stability, nerve function, and circulation around the knee.

X-Rays

These are typically the first imaging tools used. X-rays identify fracture lines, displacement, and alignment. They can also reveal if the break involves the joint surface.

CT Scans

CT may be recommended when more detail is needed, especially for tibial plateau, distal femur, or complex patella fractures. It provides 3D information about the exact fracture pattern.

MRI Scans

MRI can be helpful when soft-tissue injuries, cartilage damage, or stress fractures are suspected. It also allows assessment of meniscal or ligament structures that may influence treatment decisions.

Follow-Up Imaging

Follow-up imaging for knee fractures is often used during recovery to check that the break remains stable and is healing as expected.

Treatment Options for Knee Fractures

Knee fracture treatment varies depending on stability, displacement, and your activity level.

Non-Surgical Management

Non-surgical care may be appropriate for fractures that are stable and well-aligned. This may include:

• A brace or cast to limit motion
• Crutches or protected weight-bearing
• Gradual return to movement with physiotherapy
• Regular imaging to ensure alignment is maintained

This approach forms part of knee fracture management and aims to support natural healing while protecting the joint.

Surgical Management

Surgery may be considered when the fracture is displaced, unstable, or affects the joint surface. Surgical goals may include restoring bone alignment, supporting joint function, and reducing long-term stiffness or deformity.

Procedures may involve:

• Plates and screws to stabilise the fracture
• Tension band constructs for certain patella injuries
• Fixation techniques that respect cartilage and soft-tissue structures
• Reconstruction of ligaments if they are affected and clinically appropriate

Dr Jonathan Negus will explain the risks and benefits of each approach based on your imaging and personal circumstances.

Rehabilitation and Recovery Expectations

Recovery after a knee fracture takes time. Healing depends on bone quality, overall health, and the specific fracture pattern.

Early Protective Phase

You may need a period of reduced weight-bearing or immobilisation. This protects the bone while the initial healing occurs.

Restoring Range of Motion

Physiotherapy often focuses on gentle movement once it is safe to begin. Early mobility may help reduce stiffness, depending on your treatment plan.

Strengthening and Functional Training

As healing progresses, knee rehabilitation and strengthening can help restore gait, balance, and confidence with daily tasks. Your physiotherapist may guide exercises tailored to your needs.

Long-Term Considerations

Some people notice periods of stiffness, swelling, or sensitivity long after the bone has healed. These changes can often be managed with a gradual return to activity, alignment assessment, and load management strategies.

Recovery timelines vary, and your team will guide you based on clinical review.

When to Seek Further Review

Additional assessment may be helpful if you experience:

• Persistent pain after an injury
• Ongoing difficulty bearing weight
• Locking or catching sensations
• Recurrent swelling
• Numbness or tingling in the leg
• Concerns about your imaging or diagnosis
• Slower-than-expected progress during rehabilitation

A knee specialist or orthopaedic knee surgeon in Sydney can help identify contributing factors and outline treatment options.

Next Steps

Knee fractures can create uncertainty, especially when swelling or movement changes occur during the early stages of healing. A clinical review may help clarify the extent of the injury and the options available to support recovery.

If you are unsure how your fracture may affect your activity or rehabilitation, you can arrange a consultation with Dr Jonathan Negus to discuss your condition and treatment options.

This information is intended as a general guide and may not apply to every situation. Assessment and treatment recommendations vary depending on individual circumstances. Please speak with a qualified health professional for advice specific to your condition.