Volar Plate vs. Conventus DRS Fixation
Condition: Fractures, Closed
MeSH terms: Fractures, Closed
Study type: Interventional

Summary: 
      Open reduction and internal fixation (ORIF) of unstable distal radius fractures is performed
      using a variety of fixation techniques. The most common method is fixed angle volar plate
      application. The investigators plan to compare the outcomes of fixed angle volar plating with
      a novel FDA approved intramedullary fixation device, Conventus DRS.
    

Detailed description: 
      Distal radius fractures are the most common fractures in the upper extremity. While a widely
      used method of fracture fixation, numerous studies have shown that locked volar plate
      fixation is associated with soft tissue irritation, flexor and extensor tendon rupture, and
      screw penetration of the radiocarpal or the distal radioulnar joint (DRUJ). Prominent
      hardware mandates hardware removal in 5-18% of cases.

      Intramedullary fixation has recently received more attention in the literature because of the
      minimally invasive procedure required for device implantation. Additionally, because
      intramedullary fixation places the implant within the bone instead of onto it, the lack of
      implant exposure, as well as decreased soft tissue dissection, carries the potential for
      decreased inflammation at the surgical site. This prospective randomized case series will
      evaluate the clinical and functional outcomes of an expandable intramedullary fixation device
      and compare the complication profile with traditional fixed angle volar locked plating in a
      single-surgeon case series at a single hospital.

      The wide variety of distal radius fractures demand customized treatment, and a number of
      different surgical treatments methods are available.(1) While percutaneous/external fixation,
      dorsal plating, fragment specific fixation, and intramedullary rod fixation have been
      studied, volar locked plate fixation has emerged over the past decade as the most common and
      versatile method of fracture fixation. Unfortunately, soft tissue and hardware complications
      continue to plague volar plate fixation, including digital stiffness, loss of forearm
      rotation, tendinopathy and tendon rupture, nerve injury and compression, hardware irritation,
      screw prominence, CRPS, and malunion.

      Tarallo et al performed a retrospective review of 303 patients who had undergone volar plate
      fixation and found that implant-related complications had occurred in 5% of the patients (2).
      Of these, common complications seen were tendon rupture, screw loosening, and penetration
      into the articular space. While Tarallo et al studied only hardware related complications,
      other studies have reported complications associated of volar locking plate fixation as high
      as 22-27% (3,4). The flexor pollicis longus in particular is vulnerable to rupture, as
      hardware prominence at the watershed line of the distal radius exposes the FPL and other
      flexor tendons to frictional forces which result in fraying and rupture (5). Prominent pegs
      or screws dorsally threaten the extensor pollicis longus and neighboring extensor tendons.

      Intramedullary fixation has limited data to date, and the current methods are applicable to a
      relatively narrow subset of radial fracture types. In a case series of three patients,
      Gunther and Lynch have shown that intramedullary fixation performed with a partially flexible
      rod that can be locked into rigid position once implanted in the bone resulted in good
      functional outcomes (6). Patients returned to their daily lives and at one-year
      post-operatively no adverse effects were reported. A prospective study analyzing the
      comparative functional outcomes between intramedullary nail versus volar plate fixation
      similarly found that functional recovery was comparative between the two groups, and that
      complication rates were slightly lower in the intramedullary fixation cohort (7). The authors
      of this study however noted the continued potential for screw penetration into the distal
      radioulnar joint (DRUJ).

      The Conventus DRS expandable intramedullary fixation device used in this proposed study is
      FDA approved. A cadaveric study compared the fixation strength of the Conventus DRS with
      fixed angle volar plate fixation and demonstrated equivalency between the two for axial
      compression mean stiffness and dorsal bend mean stiffness (8). The Conventus DRS has been
      used in Europe where over 250 patients have been treated with the device. A safety and
      efficacy 'white paper' of the first 60 patients treated for a wide variety of fractures
      demonstrated excellent improvements in DASH scores with few hardware related events and an
      overall adverse event profile of 8.3%. (9) There was one re-operation for loss of fixation
      and four minor cases of neuritis that resolved. The device is FDA-approved in the US, and is
      being used across the country.
    

Intervention name(s): Conventus DRS; Volar Plate
Intervention type(s): Device; Device
Intervention description(s): The Conventus DRS (TM) is an intramedullary device intended to treat distal radius fractures. The device remains flexible during placement, but is made rigid at the completion of the surgical implant procedure. The implant is made from titanium alloy (Ti-6A1-4V) and Nitinol.; A volar plate is a metallic plate fastened directly to the fractured bone with screws, to hold the fracture fragments in proper position. Volar plate fixation is the traditional surgical method for distal radius fractures.
Other intervention name(s): Conventus DRS Intramedullary Fixation Device
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment