Dr. Paley Institute Stature Lengthening Center The Paley Institute uses the most cutting-edge technology available in the world today. In 2014, Ellipse Technologies began a new project to create the STRYDE full weight-bearing nail with Dr. Paley. The impetus was specifically for stature lengthening. Biodur 108 alloy stainless steel was chosen for its strength. In comparison to the Precice 2 nail the STRYDE nail was significantly stronger and allowed for full weight bearing. The STRYDE nail was first implanted by Dr. Paley in May 2018. Dr. Paley and Robbins implanted more than 400 STRYDE nails between 2018 and 2021.
Unfortunately the Nuvasive company decided to remove this nail from the market in 2021 due to concerns re corrosion of the stainless steel at the junction of the male and female parts of the nail. Despite this corrosion, the nail performed remarkably and lived up to its promise as a full weight bearing nail and no long-term harm was seen from this corrosion. Dr. Paley is currently working with Nuvasive to develop a titanium full weight bearing nail. Since this new nail will be made of titanium, it will not suffer from corrosion at the junction site.
We anticipate the launch of this new nail at the Paley Institute sometime in 2024. In the meanwhile the tried and true Precice 2.2 nail is the mainstay for stature lengthening at the Paley Orthopedic and Spine Institute and remains the gold standard for implantable limb lengthening today. Drs. Paley and Robbins have implanted more than 2000 Precice 2.2 nails with outstanding results.
THE ERC DEVICE GIVEN TO EACH PATIENT
The PRECICE is the most safe lengthening device available today. The PRECICE has excellent rate control and patients report minimal pain associated with lengthening.The PRECICE is the only devices on the market that has a reverse mechanism, which is a very important safety feature. The device lengthens similar to the way an antenna extends. An external remote control (ERC) is used to rotate a magnet inside the nail. This in turn rotates gears which turn a drive screw, which extends the telescopic nail.
HEIGHT GAINS WITH PRECICE
Most patients desire 3 inches (8 cm) of stature gain and some more than that. The PRECICE can lengthen 8 cm. Patients who desire more length should consider a second lengthening of the other bone. For maximum length with two lengthening, we recommend femurs first and tibias second. The total height gain with two separate lengthening is as high as 13 cm (8 cm in the femurs and 5 cm in the tibias). Greater length is not as well tolerated in the tibia and Dr. Paley highly recommends not to exceed 5 cm in the tibias, as it can lead to serious complications. Of course the cost of two lengthening is twice that of one lengthening. Although the device can lengthen as high as 8 cm, not every patient can safely achieve that much length. We will only allow lengthening to the tolerance of the patient’s bone and soft tissues. Our dictum is to never sacrifice safety and function for greater length.
The limiting factor to lengthening is usually the soft tissues. The risk of complications from lengthening increase dramatically with increased length. In a previous study we performed it showed that lengthening up to 5 cm is a low-risk lengthening; between 5 and 8 cm is medium risk; over 8 cm is a high-risk lengthening. If a patient desires more than 8cm of lengthening, it is much safer to lengthen the femur and the tibia each by 5 cm than to lengthen either bone by 8cm. It is also much better for appearance and proportions.
HISTORY OF IMPLANTABLE NAILS
While it is commonly recognized that the Soviet Union produced the greatest limb lengthening contributions through the innovations of Ilizarov, few realize that implantable limb lengthening also takes its origin in the Soviet Union. Alexander Bliskunov from Simferopol, Ukraine first published his method in 1983. This was before most of the world had heard of Ilizarov. Bliskunov developed a telescopic lengthening nail that used a crank shaft connected to the pelvis to drive his mechanism and lengthen the femur. His technology was not available outside of the Soviet Union. Others soon developed other mechanisms to drive telescopic lengthening nails. Baumgart et al, from Germany developed a motorized nail in 1991 called the Fitbone. It lengthens in one direction only. Guichet and Grammont from France, developed a telescopic nail in 1994 using a ratchet mechanism which rotated the two segments of the nail through the callus of the bone. This was called the Albizzia system and later named the Guichet Nail or Betz Bone by the two surgeons who continued to use this first generations system that could also only lengthen but not go reverse.
Cole from the US used this concept to develop a double clutch mechanism to lengthen the ISKD (Intramedullary Skeletal Kinetic Distractor) device marketed by Orthofix. This was the first FDA-approved device in 2001 but was removed from the market in 2011 due to a high frequency of rate control problems. Soubieran from France developed the Phenix nail which was acquired by Smith and Nephew and renamed the Novus. Problems with its mechanism not generating enough force caused them to abandon this project. Ellipse developed the Precice nail with Stuart Green. It became the second FDA-approved implantable lengthening nail. It had the ability to go forward and reverse. The P1 nail was first implanted by Dr. Paley on Dec. 1, 2011.
Breakage of the nail and the mechanism were identified by Dr. Paley leading to the redesign of the nail by Dr. Paley and Ellipse to create the P2 which is used to this date. In 2016 Ellipse was acquired by Nuvasive.