What is Callotasis Lengthening?
Callotasis is a new method of limb lengthening (upper or lower limbs) that involves slow, controlled distraction (stretching) of the callus (hardened tissue around bone segments) formed in response to a proximal submetaphyseal corticotomy.
In orthopedics, proximal refers to situated closer to the midsection of the bone (shaft) or to the point of attachment, submetaphyseal refers to below the upper or lower portion of the bone shaft, and corticotomy is a surgical procedure in which the cortex of the bone is cut to stimulate bone formation. The cortex is the tough mineralized part of the bone that provides the bone its rigidity. The medulla is the soft inner part that contains the bone marrow.
Callotasis lengthening involves utilizing a dynamic axial fixator with telescoping potentiality with distraction beginning after two weeks. When the needed length is achieved, the fixator is held in the rigid mode until radiographic evidence of callus is noted. The locking screw is then released, and dynamic axial loading is initiated to assist corticalization.
Indications for Callotasis Lengthening
Your physician may recommend a callotasis lengthening procedure for upper or lower limb conditions such as:
- Traumatic amputation
- Congenital anomalies
- Osteotomy (cutting and reshaping the bone)
- Limb-length discrepancy
Preparation for Callotasis Lengthening
Preoperative preparation for callotasis lengthening will involve the following steps:
- A review of your medical history and physical examination are performed by your doctor to check for any medical issues that need to be addressed prior to surgery.
- Depending on your medical history, social history, and age, you may need to undergo tests such as blood work and imaging to determine your treatment plan and help detect any abnormalities that could compromise the safety of the procedure.
- You will be asked if you have allergies to medications, anesthesia, or latex.
- You should inform your doctor of any medications or dietary supplements that you are taking or any conditions you have such as heart or lung disease.
- You may be asked to avoid medications such as blood thinners, aspirin, or anti-inflammatories for a specific period prior to surgery.
- You should refrain from alcohol or tobacco at least a few days prior to the surgery and several days after as it can hinder the healing process.
- You should not consume any solids or liquids at least 8 hours prior to surgery.
- You should arrange for someone to drive you home after surgery.
- Signed informed consent will be obtained from you after the pros and cons of the surgery have been explained.
Procedure for Callotasis Lengthening
Most current methods of bone lengthening are based on the common principles of osteotomy/corticotomy and subsequent slow progressive distraction using an external fixation device. Distraction osteogenesis (callotasis) has become an established option for reconstruction in congenital anomalies and after traumatic amputation. In general, callotasis lengthening of the upper or lower limbs commonly involves the following steps:
- You will be asked to lie down on the procedure table in a position most suitable for performing callotasis lengthening.
- General or regional anesthesia is administered to keep you comfortable and relaxed during the surgery.
- The treatment area is thoroughly cleaned with an antiseptic solution.
- The bone is sectioned at the diaphysis (central part of the bone) or at the attachment, stabilized for 2 weeks, and then subjected to gradual distraction utilizing a rigid external fixation device.
- Your physician may perform percutaneous subperiosteal “corticotomy” with the premise that preservation of the intramedullary blood supply is important to the quality of new bone formation, or a subperiosteal osteotomy in a low energy fashion with multiple drill holes and osteotome.
- Gradual lengthening involves the common principles of a low-energy periosteum sparing osteotomy and subsequent slow progressive distraction of the bone ends. The type of osteotomy, rate of distraction, timing, and distraction device can differ widely. Devices used for gradual limb lengthening can be external, internal, or a combination of both.
- The rate of callus distraction in the callotasis method is 1 mm/day divided into 4 increments (0.25 mm every 6 hours). Smaller diameter bones such as digits may be lengthened at slower rates.
- Finally, the incision is closed with sutures and a sterile dressing is applied.
Postoperative Care and Recovery
In general, postoperative care instructions and recovery after callotasis lengthening may involve the following:
- You will be transferred to the recovery area where your nurse will closely observe you for any allergic or anesthetic reactions and monitor your vital signs as you recover.
- You may notice pain, swelling, and discomfort in the treatment area. Pain and anti-inflammatory medications are provided as needed for comfort.
- Antibiotics are also prescribed to address the risk of surgery-related infection.
- Assistive devices such as splints may be utilized with instructions on restricted weight-bearing for a specified period of time.
- Instructions on surgical site care and bathing will be provided to keep the wound clean and dry.
- Refrain from strenuous activities for the first few months and lifting heavy weights for at least 6 months. A gradual increase in activities over a period of time is recommended.
- An individualized physical therapy protocol will be designed to help strengthen bones and muscles and optimize their function.
- You should be able to resume your normal activities in a couple of months, but with certain activity restrictions. Return to sports or high-intensity activities may take at least 6 months or longer.
- Refrain from driving until you are fully fit and receive your doctor’s consent.
- A periodic follow-up appointment will be scheduled to monitor your progress.
Risks and Complications
Callotasis lengthening is a relatively safe procedure; however, as with any surgery, some risks and complications may occur, such as the following:
- Neurovascular injury
- Incomplete osteotomy
- Poor regenerate bone formation
- Regenerate bone fracture
- Joint subluxation
- Joint contracture
- Muscle weakness