The debate extends to economy and effectiveness
When selecting from the wide variety of options for the treatment of intertrochanteric hip fractures, orthopaedic surgeons should keep two criteria—efficacy and cost-effectiveness—in mind, according to Kenneth A. Egol, MD.
“In evaluating new implant technology, we have to ask whether the added expense to the healthcare system actually leads to improved outcomes,” he said.
Starting with screws
The sliding hip screw is currently the implant of choice for treating most intertrochanteric hip fractures. When using a sliding hip screw, the surgeon must place the screw deeply in the central position of the femoral head and have adequate screw barrel to allow for appropriate slide.
Unfortunately, this procedure has a reported 5 percent failure rate, mainly due to screw cutout, particularly in unstable screw fracture patterns. Other adverse outcomes include limb shortening and weakness resulting from impaction of the femoral shaft. Sliding hip screws should be reserved for appropriate fracture patterns; using one in an inappropriate circumstance—such as a subtrochanteric fracture—is likely to lead to excessive sliding and potential failure. Furthermore, the procedure would require a larger exposure and possibly increased surgical time and blood loss.
Other options in a similar vein include locked proximal femur plates, Medoff plates, and percutaneous compression plates. In some cases, adding a trochanteric buttress plate to the implant to control the impaction of the proximal fragment may be an option.
“Controversies with sliding plates and screws,” Dr. Egol explained, “include the optimal size of the plate; whether to use 2-, 3-, or 4-hole plates; and what angle is best for the patient. We know that 155º is best for sliding, but that angle doesn’t meet the anatomic needs of most people; utilizing a 135º plate tends to be the best compromise.”
Nailing the fracture
Intramedullary (IM) devices, according to Dr. Egol, offer advantages such as increased rigidity, more efficient load transfer, greater mechanical strength, a shorter moment arm, less intraoperative blood loss, less soft-tissue dissection, and better resistance to excessive femoral shaft medialization.
Designed to be placed through the greater trochanter, IM devices have a valgus offset. The proximal aspect of the nail is wider than the distal aspect to allow for insertion of a lag screw. The large hole through the nail, however, is a potential weak point.
Intramedullary devices, although more expensive, have been shown to be biomechanically superior to screws and slide plates. The shorter moment arm and decreased tensile strain on the implant decreases the likelihood of implant failure.
One disadvantage of IM nails is a risk of iatrogenic comminution if there are any fractures in the bone shaft distal to the intertrochanteric region.
“This can sometimes be avoided by rotating the nail 90º,” said Dr. Egol. “Once the nail is seated and is past the fracture site, it can be turned back to the proper position.”
Other potential disadvantages of IM nailing include hardware prominence; the Z effect (penetration of the head by the lag screw) caused by a “jacking” of the implant up and down within the bone; and the fact that all current nail designs are too straight for most femurs.
In his review of the costs involved in performing the various procedures, Dr. Egol noted that IM nails are more expensive and are reimbursed at a higher rate.
“The IM nail may be a better device,” he said, “but we don’t know that yet. A critical look at the literature shows no differences in outcomes between nails and screws. Length of surgery, blood loss, technical complications, union rate, revision surgery, pain, mobility, living situation, and mortality are all similar. No study has demonstrated any functional outcome difference with the use of either of these implants. Based on this analysis, the sliding hip screw remains the treatment of choice for most intertrochanteric fractures.”
Dr. Egol ended by sharing his treatment recommendations. “For stable fractures, I use a 2-hole compression hip screw, making sure that the tip apex distance is less than 25 mm.
For unstable fracture patterns, I recommend using short nails for cost-containment purposes. For a pathologic fracture, however, I would recommend a long nail,” he said.
Peter Pollack is a staff writer for AAOS Now. He can be reached at email@example.com
Controversies course takes on disk replacement, hip fractures
Our ongoing series looking at presentations from the Top Orthopaedic Controversies course continues. This month, Fabien D. Bitan, MD, looks at spinal disk replacement, and Kenneth A. Egol, MD, compares plate and intramedullary nailing as potential treatment for hip fractures.
You can weigh in on these orthopaedic controversies. E-mail your comments to firstname.lastname@example.org or submit them in writing to AAOS Now, 6300 N. River Rd., Rosemont, Ill. 60018.