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Date of Graduation


Degree Type

Capstone Project (On-Campus Access Only)

Degree Name

Master of Science in Physician Assistant Studies

First Advisor

Judy Ortiz, PA-C, MHS, MS


OBJECTIVE: Treatment options for recurrent dislocations for patients with total hip arthroplasty are limited and have not been considered to be very successful in the past. This study will show that the use of constrained hip liner is a useful and successful treatment option to prevent recurrent dislocations. This study will also show the effectiveness of constrained hip liners for use in primary total hip arthroscopy, in conjunction with traditional implants, for patients in which non-constrained total hip arthroplasties are not favored.

STUDY DESIGN: Patients who have had a total hip arthroplasty and who were treated surgically with a constrained hip liner in clinics in Portland, Oregon and Salt Lake City, Utah were studied to analyze the success rates of their liners in preventing dislocations. The data was collected and analyzed to find the rate of failure of the constrained hip liner in preventing dislocation. Failure is defined as one or more dislocation after surgical placement of constrained hip liner.

RESULTS: 32 patients with constrained hip liners and total hip arthroplasties were studied 9 were in conjunction with primary total hip arthroplasty and 23 were used as means of prevention ofre-dislocation after prior total hip arthroplasty and subsequent dislocations. 2 patients were lost to follow-up. Of the total number of 30 patients, only 2 dislocations after placement of constrained liner were found, both of these in patients who have had previous total hip arthroplasties and subsequent dislocations. This correlates to a dislocation rate of 2 out of 30, 6.6%. None of the nine patients who had constrained liners placed with their primary total hip arthroplasty experienced any dislocations. Of the 22 patients who received constrained hip liners after a total hip arthroplasty and subsequent recurrent dislocations, 2 suffered dislocations after the revision surgery. This correlates to 2 out of 22, 9.1 % dislocation rate.

CONCLUSION: This shows, on a small scale, which is not statically Significant, that constrained hip liners are an effective treatment to prevent dislocations in patients with total hip arthroplasties.


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