Does Patient Age Matter in Revision THA?

Revision procedures may fail more often in younger patients compared to primary THA

Jennie McKee

Revision total hip arthroplasty (THA) has a significantly higher failure rate in patients who are 55 years and younger when compared to primary THA in the same age group, according to research presented yesterday.

“Younger, more active patients are undergoing primary THA, increasing the risk of implant failure and subsequent revision surgery,” noted Muyibat A. Adelani, MD, of the Washington University School of Medicine (WUSM), in St. Louis, Mo. Dr. Adelani and her colleagues sought to determine mid-term clinical outcomes of revision THA in these younger patients.

Digging into the data
The researchers searched their institution’s joint replacement registry to identify all the revision THA procedures performed there between 1996 and 2006. Their definition of revision THA included one or more components of an existing THA being exchanged, ranging from the exchange of an isolated head and liner to revision of all the components.

From a cohort of 569 consecutive hip revisions, the investigators identified 130 patients (145 hips) who were followed for 4 or more years, or until re-revision or death. Of these hips, 103 hips in 93 patients (71 percent) had satisfactory clinical follow-up or were re-revised.

The investigators defined failure as additional surgical procedures after primary THA that consisted of exchange or removal of components, including resection arthroplasty. They assessed surgical reports for type of revision performed, implant information, and type of polyethylene liner (conventional or highly crosslinked). They also examined clinical charts for data such as demographic information, primary hip disease, and body mass index (BMI). Complications considered included periprosthetic fracture, wound complication, dislocation, infection recurrent instability, or venous thromboembolism (pulmonary embolus or deep vein thrombosis).

To compare the revision THA patients to a control group, the researchers identified a group of 99 patients (103 hips) who underwent primary THA from the same database. These patients also were 55 years or younger and had been followed for at least 4 years, or until undergoing re-revision surgery. The patients in the control group were matched to those in the revision THA group based on BMI, primary hip diagnosis, Charnley classification, and selected comorbidities.

Re-revision rates, clinical outcomes, and complications of the two groups were compared. Dr. Adelani noted that the primary group was followed for an average of 6.6 years, while the revision group was followed for an average of 6.7 years.

Studying the results
Revision THA patients had a considerably higher rate of failure, with 32 hips (31 percent) in the revision group failing and requiring re-revision. In contrast, only 1 hip (1 percent) in the primary THA group required revision.

Revision THA patients also showed less improvement in Harris Hip Scores, with an average improvement of 19.2 points, versus the average 34.4-point improvement in primary THA patients (P=0.0003). Although UCLA Activity Scores for the revision patients improved an average of 0.87 points, scores for primary THA patients improved an average of 2.36 points (P=0.0008). Revision patients had a complication rate of 29 percent, while a much smaller percentage—6 percent—of primary THA patients had complications following surgery (P=0.00001).

Implications for young revision patients
Dr. Adelani concluded that “at mid-term follow-up, patients who are 55 years and younger who undergo revision THA have markedly higher failure rates.”

She emphasized that revision THA patients showed modest clinical improvement and higher complication rates compared to patients who underwent the primary procedure.

“These data are important in setting patient and surgeon expectations when contemplating revision THA in young patients,” asserted Dr. Adelani.

“Perhaps revision THA is to be avoided in this patient population,” she said. “Delayed primary THA or hip preserving procedures could be a means to this end.”

Dr. Adelani added that more study is needed to clarify the outcomes of revision THA in younger patients.

Dr. Adelani’s coauthors for Scientific Paper 170, “Revision Total Hip Arthroplasty in Patients 55 Years and Younger” include Robert L. Barrack, MD; William J. Maloney, MD; Karla Crook, BS; and John C. Clohisy, MD.

Disclosure information: Dr. Adelani and Ms. Crook—no conflicts. Dr. Barrack—Stryker Orthopaedics; Biomet; EOS Imaging; Medical Compression Systems; National Institutes of Health (NIAMS & NICHD); Smith & Nephew; Wright Medical Technology, Inc.; The McGraw-Hill Companies Inc; Wolters Kluwer Health–Lippincott Williams & Wilkins; American Association of Hip and Knee Surgeons; American Orthopaedic Association; Hip Society; Knee Society. Dr. Maloney—Wright Medical Technology, Inc.; Pipeline Orthopaedics; Abbott; Gilead; ISTO Technologies; Johnson & Johnson; Merck; Moximed; Pfizer; Pipeline Orthopaedics; TJO; Journal of Orthopaedic Research; Journal of Orthopaedic Science; American Joint Replacement Registry; Knee Society; Western Orthopaedic Association. Dr. Clohisy—Biomet; Pivot Medical; Wright Medical Technology, Inc.; Zimmer; Journal of Bone and Joint Surgery–American.

2013 Annual Meeting News
Tuesday through Friday, February 19 – 23, 2013.
http://www.aaos.org/news/acadnews/2013/AAOS11_3_21.asp