Evidence for benefit with ACS intra-articular injections in shoulder OA

Osteoarthritis

By Mardi Chapman

9 Mar 2021

Intra-articular injections with autologous conditioned serum (ACS) reduce pain and disability in glenohumeral (GH) osteoarthritis, an Australian study has found.

A Victorian study published in the ANZ Journal of Surgery reported outcomes from 36 patients and 40 shoulders at 3-6 months and >2 years after a series of six weekly injections.

Participants were over 30 years of age, had radiographic evidence of osteoarthritis (Kellgren-Lawrence Grade 2-3), and relevant clinical symptoms of pain, stiffness and disability.

Their blood was collected into dedicated Orthokine syringes containing CrSO4-coated glass beads for induction of Interleukin-1 receptor antagonist (IL-1Ra). After 24 hours incubation, the serum is filtered and divided into 2ml aliquots which are frozen until use. The usual 3 injections were delivered under ultrasound guidance by a radiologist.

The study found statistically significant improvements overall in the Shoulder Pain and Disability Index  (SPADI), Constant score, and American Shoulder and Elbow Surgeons (ASES) score at the first follow-up assessment. Patients also reported a significant reduction in pain based based on a 0-10 visual analogue scale.

“The overall scores for range of motion improved significantly for passive external rotation (p< 0.001), passive GH abduction (p < 0.01) and active elevation (p < 0.01),” the study said.

However a total of 10 patients had deteriorated in some of the outcome measures.

By the second follow-up, 16 of 40 shoulder joints had progressed to a total shoulder replacement (TSR). In the no-TSR group, improvements in SPADI were found at the second follow-up.

The researchers said they had shown promising clinical improvement in 62% of patients with an average improvement duration of 3.2 years.

“There were 13 patients (38%) considered to have little clinical improvement, but only nine of these cases (27%) required a TSR with an average time of 1.2  1.8 years after injections.”

They said ACS injections can produce short-term clinical benefit in almost all patients and postpone a TSR in 75% of patients.

“These results demonstrate that ACS injections may have a role in the conservative management of GHOA, particularly in patients who wish to delay surgery or are at increased risk with a surgical procedure,” they concluded.

While the study’s limitations include the lack of a control group, the findings were consistent with benefit previously demonstrated from use of autologous conditioned serum on knee OA.

Senior investigator of the study and orthopaedic surgeon Associate Professor Simon Bell told the limbic that some other intra-articular injections such as stem cells were somewhat controversial.

However he said Orthokine, a German product, had more evidence behind it in Europe and especially in knees where it had been shown superior to hyaluronic acid and placebo.

“This product has very increased amounts of IL-1 inhibitor compared with normal serum and IL-1 is certainly the cytokine recognised as causing inflammation.”

“I’ve generally found people tend to come back after 18 months to two years and ask for another Orthokine injection, and the second one seems to work just as well.”

Associate Professor Bell, from the Melbourne Shoulder and Elbow Centre and Monash University, said the study found no correlation between any specific predisposing factor and clinical improvement.

Accordingly, any decision between Orthokine injections and surgery required the clinical judgment of an orthopaedic surgeon.

“There is certainly some osteoarthritis in the shoulder that looks as if it is rapidly progressive and [patients] would be better off having a shoulder replacement now rather than later. There are others with no major bone loss who would then be more suitable for Orthokine.”

“Surgery is a painful experience and has risks. If I had arthritis in my shoulder that wasn’t too troublesome, if I could have an injection and not have pain for two years, I’d be pretty happy with that.”

He said there was no reimbursement for the Orthokine kit or radiology procedure.

Commenting on the study, rheumatologist Professor Rachelle Buchbinder told the limbic the results of this open single arm study are not able to confirm or refute the value of platelet-rich plasma (PRP).

“The most valid method of determining efficacy of this treatment would be to perform a randomised placebo-controlled trial. Previous RCTs of this treatment for a range of conditions including osteoarthritis have yielded conflicting results but mounting evidence based upon the most high quality trials suggests it is unlikely to be of benefit,” she said.

Disclosures: Associate Professor Bell and his colleagues reported no conflicts of interests. Professor Buchbinder declared potential conflicts of interests as she has completed two RCTs for this treatment (yet to be published) and is also completing a Cochrane review of the treatment in knee OA.

 

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