What if any are the term effects of repeated injections of…

What if any are the long term effects of repeated injections of Durolane in my hip for osteo arthritis? I am trying to avoid surgery and have had at this point in time 3 Durolane injections approximately 4 months apart. Other than some severe pain in the hip joint for about 1-2 days after the injection I have found that I get considerable relief from pain during day to day activities such as walking and stair climbing for about 4 months.
The radiologist who does these "guided" injections has said in his experience most people get about 3 months of benefit. He also said in his experience I am the only patient who has used Durolane to try to avoid surgery rather than using it to mitigate pain while waiting for hip replacement surgery as do his other patients. Being in Canada, it is not uncommon for fairly long waits for a surgery date for this type of procedure.
I am 61 years old and likely contributed to the OA in my hip by running quite a bit many years ago.
If it is considerd safe practice I am fine having these injections every 4 months or so and not have to face hip surgery for as long as possible. I know any major surgery like that has its own risks.
The doctor who has prescribed the Durolane (and refers me to the radiologist at a local hospital) for the injection is a sports medicine doctor and he advised me that he has seen some preliminary reports that hint at problems with sustained use of Durolane but he was uncertain as to the validity of these studies and indeed it was unclear to me what the potential risks might be.
Any advice you could provide would be greatly appreciated.
Thanks for your anticipated help,
Arnold Permut