Novel Fixation of Juxta-articular Fractures

Among the most demanding fractures to be fixed are those which border or involve the joints of the human body. These fractures often require the joint capsule be opened and the fracture fragments visualized such than none remain within the joint, which might inhibit ultimate function and range of motion. Nutek™ Orthopaedics, Inc. has developed a line of fixators called, NBX™ – Non- Bridging E xternal Fixation, which address peri-articular fractures, by reducing them and then uses small pins to juxta-position the fracture fragments into anatomical alignment keeping the fixation to just one side of the joint. Finally, all pins are anchored to a frame in such a way that the pins cannot advance or back out. The small pins (.062 K-wires) are placed in multiple axes and multiple directions, which give strength to the fixation, equating to or exceeding, in all planes, that of mono-lateral plates and screws, which require a surgery and an opening of the tissues surrounding a joint. Once the NBX™ is placed the patient can immediately begin a range of motion without any fear of dislodgment of the fragments, therefore no additional, supplementary splints or blocks are necessary. Nutek likens the NBX™ line more to a type of “external locking plate” than to conventional external fixators, which employ larger, threaded, sharp tipped screws and almost always have to span a joint, keeping it tensioned so the fracture fragments “settle” outside the joint. This is a huge advance in technique, when one considers that crossing the joint means joint immobilization throughout the healing process and afterwards, beginning a regimen of physical and occupational therapy.

The new thinking that was employed in developing NBX™ systems was, A) superior biomechanical consideration for the fixation (over alternative forms of internal and external fixation) with constant joint motion being the objective; B) the use of small pin (K-wire) fixation to “weave” a fracture complex together; C) the potential for a “minimally invasive” surgical technique, considering the fracture is reducible through closed indirect reduction means; D) the fact that by not bridging a joint with the fixation (and that includes a cast) allows immediate motion and function of the affected joint right after surgery; E) can be used in an outpatient setting; F) can usually be applied using a nerve block as opposed to general anesthesia, which will be meaningful for patients, who may have had to wait if they were otherwise medically compromised; and G) a device that is lightweight and may be worn, unprotected during routine bathing.

The first NBX™ fixation device was developed for distal radius fractures. Accompanying the NBX™ Wrist Fixator device itself is an optional wrist fracture reduction instrument. This fully radiolucent portable traction board assists the surgeon in stabilizing the hand and forearm, while reducing the distal radius fracture in anatomical alignment. This will now allow the surgeon to pin the fracture fragments together, while the wrist may be placed in any position atop the fluoroscope. This is a decided advantage over the fingers being placed in finger traps hung in traction because the C-arm may sit stationary in the OR suite throughout the procedure. The early clinical experience with the NBX™ Wrist Fixator suggests that it performs well in even the most difficult osteoporotic distal radius fractures so long as they are reducible. This is not to say it should be relegated to this condition alone, because all wrist fractures benefit from the fact they are unconditionally mobilized right after they are fixed. This is both a physiological and psychological boost for patients who have been treated for devastating musculoskeletal injuries.

The second NBX ™ fixator to be marketed will be one for proximal humerus fractures or shoulder fractures. Its features will be, percutaneous small pin fixation, again from multiple planes and angles, held in place by a radiolucent frame, which apparatus is contoured to the anatomy, allowing comfort while the patient sits and/or goes through a full range of motion. This device is planned to be the “easiest” course an orthopedic surgeon can take to stabilize the condition in an emergent situation, while preserving the soft tissue envelope. Of course, if the patient presents with an open fracture, external fixation is generally called for, anyway. If arthroscopic techniques need to be employed after the fracture is dealt with, the frame allows for that to happen. In this way the patient may never have to undergo an open surgery for an unstable shoulder injury and yet this will allow the patient to undertake an active range of motion, which is unprecedented.

NBX™ products were designed to be used by all orthopedic surgeons in emergent situations. Juxta-articular fractures are complex and many times are reserved for the orthopedic specialist. Therefore, the product line was designed to be easy to comprehend and place on a patient as soon as possible. If the situation was felt to demand a further reconstruction or alternative means of fixation the NBX™ product is very easy to remove and “no bridges have been burned” in putting it on in the first place. Clearly, the NBX™ System is a major advance in the treatment algorithm of fixing juxta-articular fractures.