EPIPHYSIODESIS

Epiphysiodesis Explained

When the condition of the patient allows, our surgeons can perform an Epiphysiodesis. This minimally invasive surgical procedure will slow or stop the expansion of a bone. The procedure is solely for kids to equal the length of their legs.  The procedure will slow or permanently stop the longer leg from growing. Doctors refer to epiphysiodesis as growth plate fusion.  Therefore, we provide the shorter leg a chance to “catch up” with the longer leg.  This procedure does not work for adults as they have stopped growing.  Each of the long bones of the lower limb (femur, tibia, and fibula) has growth centers at the top and bottom of the bone.

Our surgeons can selectively slow bone growth by targeting one or more growth centers in the long leg bone. Epiphysiodesis is a procedure that temporarily or permanently fuses epiphyseal plates (growth plates) to slow or stop growth in a healthy leg. This does not immediately fix leg length discrepancies. Instead, the leg length discrepancy slowly diminishes as the shorter limbs catch up.

Growth Plates

Growth plates are responsible for bone growth in children. They are located near each end of the humerus (upper arm bone), ulna/radius (forearm), femur (thigh bone), and tibia/fibula (shin bones). The growth plate consists of a thin layer of cartilage (1/10 of an inch, ~3 mm) that exists at the ends of the bone. The growth plate cartilage is different from the cartilage in the joints (knee, ankle, etc.).

When to Use the Epiphysiodesis Procedure

Our doctors consider Epiphysiodesis when a child may have a limb length discrepancy between 2 and 6 cm (0.8 to 2.4 inches) at maturity. Our surgeons perform the Epiphysiodesis surgery on the long/healthy leg. Stopping the growth of the longer leg will minimize the amount of lengthening required for the shorter leg. Ultimately, patients may not reach their tallest potential height after undergoing this process. However, their legs will be of equal length. Most bone growth in the legs happens near the knees, so the growth plates that are closest to the knee in the femur (thigh bone) or tibia (shin bone) are the ones that are typically fused. To repeat, this procedure stops/slows the growth of the long healthy leg.  Therefore, the procedure gives the short leg the opportunity to “catch up” through natural growth.  Eventually, the short leg matches the length of the long leg.

Accurate Height Prediction

Timing is key for this procedure. A surgeon must accurately predict the full potential height of the child and determine when to start the procedure.  The procedure should begin so that limbs are near-equal length by the end of the child’s skeletal growth. Despite all of medicine’s technological advances, determining the exact time to perform an epiphysiodesis procedure remains an educated guess. The surgeon needs to evaluate the remaining growth potential and decide when to stop growth in order to obtain the desired correction. The surgeon also needs to choose which growth center (or centers) need to stop to obtain the correction. This evaluation process remains an inexact science. In most cases, our surgeons will accurately estimate the timing.  However, it is possible to under-correct or over-correct the leg lengths with epiphysiodesis.

Performing Epiphysiodesis Surgery

Typically, the child/adolescent will undergo general anesthesia for about an hour for this minimally invasive surgery. When the bone becomes resected or removed, a part of the longer bone gets cut and the ends are connected and held together by metal screws. During the surgery, the growth plate gets scraped or drilled to prevent it from growing further. In many cases, the surgeon will use staples to control its growth. Your doctor will remove the staples once the other leg’s length matches the corrected leg. A 1-inch (2.5-cm) incision is made and the growth plate is fused. Temporary epiphysiodesis is accomplished with eight-Plates and screws.

Permanent epiphysiodesis is more common and is accomplished with surgical removal of the growth plate using a special drill. During the actual procedure, the surgeon makes a long incision in the skin on top of the targeted bone. The surgeon will perform the necessary steps and then close the incision using sutures. The leg is then covered with a cast that remains in place until the bone is completely healed. It is expected that the patient will stay in the hospital for a few days after for close monitoring.

What happens after Epiphysiodesis Surgery?

To evaluate the procedure in the knee, the patient must visit the doctor two weeks following the procedure. After surgery, the patient can put weight on the leg and can resume regular activities in two to three weeks. Follow-up appointments are scheduled every 4 months or so.  This will allow the doctor to keep track of the development of both the long and short legs. Regular monitoring takes place since epiphysiodesis sporadically results in the leg becoming twisted.

Possible Risks and Complications

While the bone heals, the patient could feel moderate to severe pain or discomfort. Bone atrophy is a significant concern as well, but with physical therapy and the right activities, problems should not exist. Balance issues, bleeding, and scarring are examples of additional hazards or consequences. Additionally, an infection at the wound site has the potential to impede the patient’s healing. Legs can still develop unevenly if the operation to correct unequal bone length is performed at the wrong time.  This could cause the patient to undergo the treatment once again.

Permanent Epiphysiodesis

A bone bridge that anchors the growth plate and stops further development is the end result of permanent epiphysiodesis. A bone bridge between the physis and metaphysis may develop as a result of the ablation to the medial and growth plate’s peripheral edges. Though it is frequently drilled in practice, the middle portion of the physis does not, in principle, need treatment because it will naturally close. This technique is recommended for projected 2 to 6 cm longer leg length disparities. It is possible to do temporary epiphysiodesis, but permanent epiphysiodesis, which totally halts development at a specific physis, is more frequently used. The growth plate closest to the knee is where the majority of lower extremity development takes place.

Special Preparations

A common outpatient procedure with low morbidity is epiphysiodesis. Before the procedure, your kid might need to abstain from food, beverages, or some medications. To confirm that the time is appropriate and the infant is a strong candidate for epiphysiodesis, a variety of tests are necessary for advancement. For around 6 weeks following surgery, activities are often limited.

Risk Factors

Epiphysiodesis error and complication rates are unknown because there hasn’t been a significant study of patients who have undergone the procedure. These issues can include infections, damage to the nerves, or an imperfect epiphysiodesis procedure, which frequently results in an angular deformity. A sizable patient group has been studied in order to obtain information regarding the frequency of complications and characteristics linked to them. Potential side effects of epiphysiodesis include infection, hemorrhage, harm to the healthy limb, overcorrection of the disparity, and under correction of the leg length discrepancy. Research also provided information that  the temporary epiphysiodesis procedure frequently results in complications.

Hemarthrosis, knee effusion, chronic knee discomfort, and wound infection have been reported as side effects of surgery. There have been reports of screw breakage, screws not placed in the correct position, and implant-related problems such as screw loosening. Angular deformity and permanent damage were physical consequences. It was shown that 20% of cases using screws and up to 50% of cases using staples experienced an angular deformity. The risk variables for those patients who had problems were younger, congenital rather than acquired abnormalities, and higher leg length disparities at the time of the epiphysiodesis procedure.

Conclusion

However, these tendencies did not reach statistical significance. Other trends toward open curettage, epiphysiodesis involving the femoral growth plate, and male gender as risk factors were also present. In order to take extra precautions, surgeons need to recognize which patients are more vulnerable to difficulties during this treatment. In order for parents to make an informed decision, they should read about this treatment.  Also, parents should know that there is a 5% chance of surgical complications and that there are other procedures to achieve a more exact and better result.