Knee Fractures- Causes, Signs and Healing Time

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Knee Fractures- Causes, Signs and Healing Time

What happens next when you have a fracture in or around your knee? What is a fracture ? A fracture is a complete or incomplete disruption of the osseous integrity of a bone. Tibial condyle fractures, patellar fractures, femur fractures and fracturesknee fracture - of the shafts of the tibia and fibula are some of the more common fractures around the knee.

It is important to understand the classification of fractures by anatomical location such as the femur, tibia, etc. and the direction of the fracture whether it be spiral or oblique. It is also important to understand the mechanism of the injury such as how it occurred, was it open or closed, complete or incomplete, was the angulation posterior vs medial, and what is the joint or epiphyseal involvement.

Causes of Knee Fractures

There are also many causes of fractures such as: 

- Trauma like falling on an outstretched hand (FOOSH)
- Compression
- Avulsion
- Overuse or fatigue can also cause fractures such as stress fractures.

A pathological bone fracture is a fracture through a bony area which has been weakened due to some abnormality such as a stress which would not break a normal bone. An example of this could be severe osteoporosis where the bones become more brittle and are prone to fractures. Many types of fractures are possible such as transverse, oblique, impacted, compound, comminuted and many more.

How Can You Tell If You Have a Fracture?

Knee Fracture- SportsBraces.comSo how can you tell if you have a fracture? Sharp, localized pain, swelling, a deformity, bruising, reluctance to move the injured limb or area, and cradling or supporting the injured area are all possible signs. Additionally, when palpating, there is pain with compression or vibration (use a tuning fork) and there can be muscle spasm and crepitus (creaking noise). Passive movements can elicit pain and often times the joint is restricted. Finally, an x-ray would be positive but for more obscure fractures a bone scan, CT scan or MRI may be indicated

How Long Will It Take For My Fracture To Heal?

You may ask yourself how long it will take for my fracture to heal. Here are some of the factors that influence the healing.  Circulation is a huge factor. Bones that have inadequate circulation often heal slowly. Luckily in the knee this often isn’t the case. Bones that have an articular surface have little area for periosteal circulation and are at risk of developing avascular necrosis.

Segmented or badly comminuted fractures may have avascular fragments which delay healing.  Severe dietary restrictions can delay healing. Also age is a factor. The younger you are the faster you heal. With increasing age, bone becomes more brittle and less stiff.  So, less strong and more porous material with fewer, thinner and longer trabeculae develop. The upper limb also heals faster than the lower limb.

Fracture shape plays a role. For example the transverse fracture takes longer to heal than a spiral fracture. The amount of of displacement of the fractures is something to take note of also. Fractures with greater displacement and comminution will take longer to heal than a simple undisplaced fracture.

Infection, anemia and hypoxia will slow fracture healing. Health and fitness is critical. Vitamin C is required for normal collagen matrix formation and proper exercise shown by a licenced physical therapist will increase fracture healing.

Finally the type of bone plays a role in the healing time. Intra-articular fractures take longer to heal than extra-articular fractures due to the presence of synovial fluid hindering the formation of granular tissue. So if you have a fracture within the knee joint, then it is likely that your fracture will take longer to heal than outside of the joint.  Depending upon your specific fracture, you may be allowed to bear weight on your leg while wearing a cast or brace. With some fractures, however, weight bearing is not allowed for 6 to 8 weeks.

Author: Avi Bregman, PT, MPT

Avi Bregman


Avi Bregman is a licensed Physical Therapist in the state of Florida.  He received his education at the University of Western Ontario in London, Ontario, Canada where he graduated with Honors with a Bachelor of Science Degree in Kinesiology. Later, he completed his Master of Physical Therapy Degree at Western University. 

Avi holds a Manual Therapy Certification and has practiced in Florida for over 10 years in the field of outpatient orthopedics and neurological rehabilitation. 

Avi is a Credentialed Clinic Instructor for PT and PTA students through the American Physical Therapy Association. He has also earned additional specialized training in Golf Rehabilitation, Acupuncture and is Mckenzie Certified. Avi’s love for the field of golf rehabilitation led him gain TPI Certified expert status through the Titleist Performance Institute.

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