Hemi-epiphysiodesis: Definition, Purpose, Preparation, Procedure, and Results
Children and adolescents can sometimes develop pathological angular deformities in their lower extremities and this can cause them pain whenever they are off playing or doing activities. These deformities can also sometimes cause altered gait as well as joint instability and can be made worse by the children’s continued growth.
These deformities, however, can simply be corrected by using hemi-epiphysiodesis. Although the correction involved is gradual and is done with growth, hemi-epiphysiodesis effectively allows the patients to achieve equal limb-lengths, neutral axial posture and equally horizontal knees with skeletal maturity. As opposed to most corrections involving surgery, hemi-epiphysiodesis allows for these results without destruction of any part of your bone structure, physis or without involving any kind of major surgery.
What is Hemi-epiphysiodesis?
Hemi-epiphysiodesis is also known by the term guided growth, and is generally a surgical technique involving the gradual correction of an angular limb deformity, most commonly in skeletally immature patients or those patients who have not yet fully developed their skeletal system, such as in kids.
What is the Purpose of Undergoing Hemi-epiphysiodesis?
Hemi-epiphysiodesis is a surgical option for people that are seeking an alternative to corrective osteotomies (osteotomies are surgical operations whereby a bone is cut to either shorten or lengthen it or change its alignment). Hemi-epiphysiodesis provides a surgical operation wherein the patient feels less pain, shorter immobilization, an overall lesser surgical risk and a generally decreased cost, hence providing an ideal alternative to most surgical procedures involving the bone, like osteotomies.
Types of Hemi-Epiphysiodesis
There are generally two types of hemi-epiphysiodesis procedures, one is known as Temporary Hemi-epiphysiodesis, and the other involves the extraperiosteal, 2-hole plate method.
- Temporary Hemi-epiphysiodesis involves plating or stapling but can be generally complicated by the premature physeal closure (physeal closure involves bony bridges developing the epiphysis and the metaphysis that can lead to many bone deformities), and also a rebound period of accelerated growth within the bones of those areas, as well as migration of the hardware used. There are much lesser complications involved with another form of hemi-epiphysiodesis, the 2-hole plate method.
- The 2 hole-plate method hemi-epiphysiodesis mostly involves a parallel screw configuration but can also be done using a divergent screw configuration. Although the parallel screw configuration has been proven to be much more efficient than the divergent screw, both forms of 2-hole plate method hemi-epiphysiodesis are controversial in the medical literature.
How to Prepare for Hemi-Epiphysiodesis
Hemi-epiphysiodesis generally begins with preoperative assessment done by a physician on you. Most commonly, preoperative assessment for hemi-epiphysiodesis involves measurement of your limb lengths as well as clinical angular and rotational deformities you may have. A physical exam will also be included, that will sometimes involve assessment of various functions in your body involving the bone including long bone torsion, gait pattern, patellar tracking and ligamentous laxity. Your doctor can also subject you to radiographic assessment of leg lengths as well as other deformities in your body, and this will involve x-ray or other imaging medical procedures.
When your doctor deems you physically fit and with low enough surgical risk, you will then undergo the surgical procedure after having been set with a schedule.
Hemi-epiphysiodesis: How is the Procedure Performed?
Hemi-epiphysiodesis usually involves placing bone clamps or staples around the growth plate of the bone affected. As the procedure is surgical in nature, the doctor (or specialist) will do this on a surgical table, and you will be anesthetized accordingly so as to not feel pain. The bone clamps will be placed at the appropriate time, months before the bone will complete its growth phase and over the next 1 to 2 years, the bone’s growth will be redirected from its normal deformed growth and will proceed to a straightening of the legs. Depending upon your physician’s assessment, the bone staples or clamps can be left in place once the goal is achieved and the bone deformity is made straight.
Hemi-epiphysiodesis: Results and Post-operative Care
As mentioned before, results involving hemi-epiphysiodesis will generally show in 1-2 years, during the continued growth phase of the child or adolescent. The bone clamps will either be left in place to further prevent deformities or will be removed when the physician or specialist deems the deformity to be permanently cured.
Physical therapy will be necessary in order to regain the range of motion and strength required in most normal day to day activities, especially right after the operation. Radiographs and follow-up imaging tests will sometimes be required every 3 to 6 months in order to monitor the corrected growth and activity of the deformity.
Sometimes the deformity may not be corrected with the use of hemi-epiphysiodesis, and this can be corrected by cutting, straightening or allowing the bone involved to heal in the new and corrected position. During this process, there will be continued use of bone screws, clamps, and plates in order to keep the bone straight during the whole process.
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