Tuesday, May 25, 2021


Blog Topic:          ApiFix MID-C                                                                  5-25-2021


Non-fusion technologies for the treatment of scoliosis in the growing patient, has garnered increasing interest from patients and surgeons over the last 10 years.  The advantages have been touted as being a minimally invasive procedure, rapid postoperative recovery, faster resumption of normal activities, less postoperative pain and preservation of more spine motion, when compared to spinal fusions. 


The first system used for Anterior Vertebral Body Tethering (AVBT) was the Zimmer Biomet Dynesys system.  This system was originally designed for use in adult patients and in the posterior spine, and was used in an off-label/unlabeled manner in the anterior spine in the growing patient.  This was the precursor system to their current system which achieve FDA approval for use on the anterior spine in growing patients in August 2019.  The pluses and minuses of this surgical treatment has been previously posted on this blog, so I will refer those interested to scroll back through the blog to those posts (May 2017, November 2017, January 2018 x 2, and February 2018).

Another growth modulation system, the ApiFix Minimally Invasive Deformity Correction (MID-C) system, was also approved in August 2019.  Unlike the AVBT system, there was no similar device which could be used in the U.S. prior to the FDA approval.  Most of the clinical experience with this system, which was used for FDA approval, was from outside the U.S.  This means there is much less clinical experience with this device, when compared to AVBT, in the U.S.

As opposed to the AVBT system, which is placed on the front of the spine and compresses the convex side of the curve, the MID-C system is placed posteriorly and distracts on the convex side of the curve.

As you see above, there are two pedicle screws on the top and one at the bottom.  The mechanism is in the middle, which ratchets apart with bending. 


At present the current indications for the use of the ApiFix MID-C are:

               Lenke 1 (thoracic) or 5 (lumbar) curve patterns

               35-60 degrees coronal deformity

               SB to </= 30 degrees

               T5-T12 < 55 degrees




The surgical technique looks similar to a posterior spinal fusion, due its skin incision.  However there is not as much dissection or blood loss, so recovery is faster


At present the MID-C and AVBT have similar indications


To learn more about ApiFix MID-C:




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