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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 MHS, MS, PA-C

Second Advisor

Jonathan W. Gietzen, MS PA-C


Objective: Retrospective descriptive analysis comparing Synvisc and Hyalgan hyaluronic acid intra-articular injections for osteoarthritis of the knee. Synvisc is a higher molecular weight viscosupplement than Hyalgan. The studies comparing the various hyaluronic acids disagree on which hyaluronic acid is more effective. Design: Patients at Mountain Vista Orthopedics with a diagnosis of osteoarthritis who received series' of Hyalgan or Synvisc injections to the knee between January 1st 2000 and December 31 st 2004 were selected for chart review. The patient's decision to obtain a total knee replacement or an additional series of injections was used to compare the effectiveness of each hyaluronic acid. The time frame between series of hyaluronic acid injections was calculated in weeks as was the number of weeks between last injection and total knee replacement.. Statistical analyses of the mean, median, mode and standard deviation were used to compare length of effectiveness of Hyalgan and Synvisc. Results: Of the 238 patients selected, 120 received Hyalgan and 82 received Synvisc. There were more females than males with equal percentages in each group evaluated. In the Hyalgan group, 50 knees received a TKA, and 40 knees received a TKA in the Synvisc group. The average number of weeks difference between last set of injections and TKA was larger for the Synvisc group than for the Hyalgan group. The average difference, in weeks, between series' of injections was also greater for the Synvisc group than it was for the Hyalgan group. All results suggesting patients who receive Synvisc wait longer than patients who receive Hyalgan before obtaining another treatment. Conclusions: The results indicate that Synvisc is a more effective hyaluronic acid for treatment of osteoarthritis of the knee when compared to Hyalgan. On average, patients waited longer after having a series of Synvisc injections before receiving an additional treatment option. However, Synvisc was used prior to Hyalgan at this particular site allowing Synvisc more time to be judged as effective. Even so, within the parameters of this study, Synvisc can be labeled as a more effective hyaluronic acid injection for treatment of osteoarthritis of the knee than Hyalgan from the results obtained.


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