Bone formation during limb lengthening is divided into 3 phases: the distraction, consolidation and remodeling phases. So far, limb lengthening involved the use of fully implantable intramedullary nails. On average, how long is the recovery time for patients with intramedullary nails compared to patients with the new orthopedic implants?
The distraction phase is the critical phase because it requires the most experience. In this setting, the bone is usually lengthened 1 mm per day. That is to say, if you want to achieve 30 mm in length, the distraction phase lasts 30 days. There is no change during this phase, except that unlike patients with conventional implants, our patients are soon able to walk without the aid of crutches. The consolidation phase is next. Previously, the normal length of the consolidation phase is either as long or twice as long as the distraction phase. That is to say, limb lengthening of 30 mm takes 30 - 60 days of consolidation. A major characteristic of this phase is much faster bone regeneration and significantly improved general recovery. I am certain the faster recovery is a result of full weight-bearing. Remodeling takes several months. Patients are barely restricted during this phase. In my view, this phase is comparable to the time required by earlier implant models. In your opinion, what are the features of a perfect orthopedic implant?
A perfect intramedullary lengthening nail should have a safe and strong actuator, that is to say, it should not shorten when subjected to weight-bearing. The actuator should also facilitate a controlled shortening. The shortening of the intramedullary nail should not require anesthesia or need for surgery
for the patient. What’s more, the actuator should also be robust and prevent uncontrolled backtracking. Full weight-bearing is likewise an important characteristic, which is now a feature of our approved new implant
. Miniaturization is equally important because not every bone is big enough to place an earlier implant model. In this case, we would appreciate intramedullary nails that are thinner and possibly shorter but still ensure the same lengthening capacity. This would allow us to use intramedullary nails in bones that were previously too small for these types of procedures. Having said that, it is important to take static, structural and material limitations into account.