Data presented at the 2012 annual meeting of the American Association of Hip and Knee Surgeons suggest that using a cephalomedullary nail (CMN) for fixation of an intertrochanteric hip fracture may increase the risk of complications during conversion total hip arthroplasty (THA), compared to prior fixation with sliding hip screw and side plate (SHS) devices.
“CMN devices have become increasingly popular in the treatment of intertrochanteric hip fractures,” explained presenter Christine M. Pui, MD. “But if fixation fails, or if degenerative disease of the hip develops, conversion to a THA may be needed.”
Dr. Pui noted that conversion THA surgery is considered technically more difficult than primary THA, may require significantly more operating room time, and may be associated with a greater risk of complications.
Retrospective review study
The study, a retrospective review of computerized databases from several institutions, covered the period 1999–2009. Researchers identified 91 hips (91 patients) who underwent conversion surgery to THA following treatment of intertrochanteric hip fracture with either SHS or CMN devices. Sixty patients had been treated with SHS devices and 31 had been treated with CMN devices.
The average follow-up after conversion to THA was 37 months for patients in the SHS group and 35 months for patients in the CMN group. The research team found no significant difference in Harris Hip Scores between the groups at final follow-up. In the SHS group, Harris Hip Scores improved from a mean 41.6 preoperatively to 83.6 at final follow-up; in the CMN group, scores improved from 41.6 preoperatively to 78.6 at final follow-up.
“We did note, however, that the complication rate—at 41.9 percent—in converted CMN patients was significantly higher than the 11.7 percent complication rate among converted SHS patients,” said Dr. Pui. “And when we looked specifically at orthopaedic complications, the CMN group sustained twice as many complications as the SHS group.”
According to Dr. Pui, orthopaedic complications included periprosthetic fractures, dislocations, infection, intraoperative nerve injury, and heterotopic ossification. Medical complications included pulmonary embolism, postoperative atrial fibrillation, acute renal failure, cerebral vascular accident, postoperative gastrointestinal bleeding, and urinary tract infections.
Conversion a good option
“Conversion to THA is a good option for failed fixation of intertrochanteric fractures,” said Dr. Pui. “However, prior fixation with CMN may be associated with significantly higher total and orthopaedic complication rates during conversion THA, as compared to prior fixation with SHS devices.”
Dr. Pui’s coauthors for “Increased Complications Following Total Hip Replacement after Cephalomedullary Fixation for Intertrochanteric Hip Fracture” include Mathias P. G. Bostrom, MD; Geoffrey H. Westrich, MD; Craig J. Della Valle, MD; William B. Macaulay, MD; Michael A. Mont, MD; and Douglas E. Padgett, MD.
Disclosures: Dr. Pui—no conflicts. Dr. Bostrom—Smith & Nephew; Springer; Orthopaedic Research Society. Dr. Westrich—DJ Orthopedics; Exactech; Stryker; Eastern Orthopaedic Association. Dr. Della Valle—Biomet; Convatec; Smith & Nephew; CD Diagnostics; Stryker; Journal of Bone and Joint Surgery–American (JBJS–A); Orthopedics Today; Arthritis Foundation; Knee Society. Dr. Macaulay—Pfizer; Wright Medical Technology; Clinical Orthopaedics and Related Research; Journal of Arthroplasty (JOA). Dr. Mont—Stryker; Wright Medical Technology; Biocomposites; DJ Orthopedics; Janssen; Joint Active Systems; Medtronic; Sage Products; TissueGene; National Institutes of Health; American Journal of Orthopedics; JOA; JBJS–A; Journal of Knee Surgery; Surgical Techniques International. Dr. Padgett—Mako; Stryker; JOA.
Peter Pollack is a staff writer for AAOS Now. He can be reached at firstname.lastname@example.org
- Conversion to THA is a “good option” for failed fixation of intertrochanteric fractures.
- The risk of complications is higher, however, when the fracture was treated with CMN fixation, compared to SHS fixation.
- Risk of orthopaedic complication in patients treated with CMN fixation was twice that in patients treated with SHS fixation.