- Clinical and radiographic outcomes of patients treated with non-spanning external fixation are comparable to those treated with open reduction and internal volar locked plate fixation.
- Non-spanning external fixation can lead to satisfactory outcomes based on the following features: fragment specific fixation, subchondral support, fixed angle strength, limited dissection, distraction/length adjustment, joint distraction avoidance, and ability to perform early rehabilitation.
- Non-spanning external fixation should be considered as a treatment option for complicated unstable comminuted intra-articular distal radius fractures, specifically in the elderly.
In the United States, distal radius fractures (DRFs) are among the most common fractures, comprising about 15% of all extremity fractures. 1 With a DRF, the primary treatment goal is anatomical reduction with restoration of radiographic parameters and stable fixation of the fracture to restore wrist function.
This fracture type has a variety of treatment alternatives, including nonoperative closed reduction and casting of stable fractures, open reduction and internal fixation (ORIF) with dorsal or volar locking plates, and external fixation. Optimal surgical management of unstable DRFs remains controversial. 2 Closed reduction with percutaneous pinning or external fixation has become less common with a trend toward using volar locking plates for internal fixation. 3
External fixation of DRFs traditionally has involved either spanning or simple nonspanning devices. Spanning fixation is particularly useful in open or highly comminuted fractures with an unstable soft-tissue envelope. In the past, nonspanning external fixation typically was reserved for fractures with a noncomminuted extra-articular distal fragment to which several large pins or Kirschner wires (K-wires) could be secured. The Non-Bridging External Fixator (NBX; Nutek Orthopaedics) may be used in cases that traditionally might be treated with locked plating or fragment-specific fixation. Specifically, this device is indicated for comminuted intra-articular DRFs in which bone quality may be less than ideal. The NBX, also suitable in open fractures with a stable soft-tissue envelope, can restore and maintain articular alignment by providing subchondral support and stability with fragment-specific fixation. A key advantage of this type of external fixation is that it involves percutaneous fixation and allows for early postoperative range of motion (ROM).
Numerous studies have found excellent outcomes of treating unstable DRFs with ORIF with volar locking plates. 4-6 However, few studies have compared the clinical and radiographic outcomes of ORIF with those of nonspanning external fixation in the treatment of unstable comminuted intra-articular DRFs. Windolf and colleagues 7 found that, in cadaveric unstable intra-articular DRFs, nonspanning external fixation with multiplanar K-wires had biomechanical characteristics comparable to those of volar locking plates. Other suitable DRF treatment options have been found: an alternative nonbridging external fixator with multiplanar K-wires (Gradl and colleagues 8) and the Cross-Pin Fixation system (A.M. Surgical) (Mirza and colleagues 9).
We conducted a study to compare functional and radiographic outcomes of unstable comminuted intra-articular DRFs treated with a nonspanning external fixation device (NBX) with outcomes achieved with volar locking plates in a historical control group.
Materials and Methods
This retrospective case-control study was approved by our Institutional Review Board and conducted at 2 institutions. Included in the study were 25 consecutive patients (2 institutions) who underwent closed reduction and external fixation (CREF) with NBX as treatment for unstable DRFs (diagnosis based on radiographic parameters or inability to maintain acceptable alignment after closed reduction and casting). Of these 25 patients, 11 were available for clinical follow-up and medical records review; the other 14 were not available for followup but had their charts reviewed for radiographic data and treatment details. Six of the 14 patients declined to participate in the study, and the other 8 were lost to follow-up because of nonstandardized follow-up protocols. Patients were excluded from the study if their final follow-up had not occurred, or if it occurred before 6 months. For their participation in clinical follow-up, patients received nominal time compensation and mileage reimbursement through a grant from the NBX manufacturer.
The 25 patients underwent CREF with NBX between November 2008 and March 2013. Indications for external fixation consideration were intra-articular extension or significant comminution in patients with poor soft tissue or in patients who wanted to avoid invasive surgery or a permanent implant. Of the 11 patients who agreed to participate in the study, 7 were women and 4 were men; mean age was 64 years (range, 15-81 years). Of the 14 patients unable to follow up, 11 were women and 3 were men; mean age was 63 years (range, 26-89 years). At the last available follow-up, each of the 25 patients was doing well, was satisfied with treatment