While most fractures and surgical repairs heal normally, bone healing can be affected by disease and other patient factors. A commonly occuring result of poor healing is a nonunion.
Interbody Spine Fusions
Anterior Lumbar Interbody Fusion (ALIF)
ALIF surgery treats lower spine instability or disc disease. Anterior means "from the front". In other words, the surgeon approaches the spine through the abdomen rather than from the back. The purpose of this approach is to treat the front of the spinal segment being corrected. One advantage of ALIF is avoidance of nerves and back muscles during surgery. However, surgeons need to avoid the aorta and vena cava when approaching the spine from the anterior.
When treating collapsed disc spaces using the ALIF procedure, bone graft materials or titanium cages are inserted into the vertebral space to reinforce the spine and relieve pressure from the nerve roots.
Posterior Lumbar Interbody Fusion (PLIF)
PLIF approaches spinal instability or degenerative disc disease from the back. In this operation, bone graft materials or cages are inserted into the disc space, while cutting away bone to free up the nerve roots. However, the posterior approach (PLIF) is more difficult than the ALIF, due to difficulty with exposure, available surface area for healing and the fact that a posterior approach is used to treat an anterior part of the spine. PLIF has a greater chance of nonunion than ALIF.
Transforaminal Lumbar Interbody Fusion (TLIF)
Difficulties encountered with PLIF lead to the development of TLIF. More of the vertebra is removed to increase the exposure and allows for a larger implant to be used in the vertebral space. TLIF and all lumbar interbody fusions run the risk of nonunion. The chance of a nonunion is affected by cigarette smoking, nutrition, obesity and a history of previous surgery.
Foot Nonunions
Nonunion, or failure of the bone to fully heal, is one of the most common complications of foot fractures and surgery. A patient's health and lifestyle choices can affect bone healing following injury or surgery. Diabetes and obesity are two factors. The heavier a patient is, the more weight the feet need to support, thus making it difficult to avoid weight bearing on the affected limb. Diabetes affects healing in the lower extremities, therefore, careful attention to insulin levels is crucial to heal bones.
Surgeons may use immobilization n order to prevent nonunions. This keeps weight off of the foot. External fixation is a newer alternative to casting and may be suggested. External electrical bone growth stimulation is often recommended for foot nonunions. Often, bone stimulation is begun during initial healing to prevent nonunion, or in the case of nonunion, to encourage healing.
If surgery is required to repair a nonunion, metal hardware and bone grafting are typically used.
Humeral Nonunions
A broken arm is one of the most common orthopedic injuries, especially in children and in athletes. The upper arm bone, called the humerus, is less commonly injured and accounts for approximately 3% of all fractures. Most humeral fractures are treated with immobilization, a cast. However due to the inability to fully immobilize the upper arm, surgeons may consider surgery for a greater chance of healing properly. A nonunion may occur, requiring repeat surgery, external fixation, or electrical bone growth stimulation.
Leg Nonunions
Most leg fractures will heal normally either with immobilization, internal or external fixators, or surgery. However, depending upon patient condition and other risk factors such as obesity or smoking, a nonunion may occur. Nonunions occur when the healing bone lacks adequate blood supply and/or stability. Nicotine is thought to interfere with bone healing. Diabetes and the use of certain medications such as prednisone, aspirin or ibuprofen can also negatively impact bone healing. Adequate dietary nutrition is also essential.
If a bone has a nonunion, your physician will recommend treatment, either surgical or non-surgical. An external bone growth stimulator is an effective way to help the bone heal. The stimulator produces electrical or ultrasound energy which encourages the natural bone healing process.
If non-surgical treatments are not effective, surgery may be required to repair the nonunion. Bone graft materials, either from the patient or from a cadaver, or enhanced bone graft products such as DBM, can help the body heal by providing fresh bone cells and nutrients needed by the bones. In addition to bone grafts, your surgeon will often place internal screws and plates to hold the bone together.
External fixation may also be used.