The incidence of flare reaction and short-term outcome following steroid injection in the shoulder

Local and Systemic Side Effects of Corticosteroid Injections for Musculoskeletal Indications

Corticosteroid injections can be associated with a range of potential side effects, which may be classified as local or systemic and further stratified as immediate or delayed in onset. Radiologists performing image-guided musculoskeletal injections should recognize the potential side effects of corticosteroid medication when counseling patients before injection and consider such side effects in planning individual injections. This Review summarizes the available evidence regarding the local and systemic side effects of corticosteroid injections performed for musculoskeletal indications. Local side effects include postinjection flare, skin hypopigmentation and atrophy, infection, tendon rupture, accelerated progression of osteoarthritis, and osseous injury. Systemic side effects include adrenal suppression or insufficiency, facial flushing, hypertension, hyperglycemia, and osteoporosis. Additional targeted counseling is warranted regarding side effects that are specific to certain patient populations (i.e., premenopausal women, patients with diabetes, athletes, and pediatric patients). Corticosteroid injections are contraindicated in the presence of superficial or deep infection, fracture, or a prosthetic joint. Guidelines on the frequency, duration, and maximal lifetime use of corticosteroid injections are currently lacking. Further research is needed regarding the long-term complications of continuous corticosteroid use, particularly with regard to osseous effects.

Comparing the Intensity of Pain and Incidence of Flare Reaction Following Trigger Finger Injections Using Betamethasone and Methylprednisolone: A Double-Blinded, Randomized Controlled Trial

BACKGROUND

Considerable evidence supports corticosteroid injection as an effective treatment for trigger finger. One common side effect, the flare reaction, is a well-documented phenomenon of increased pain following steroid injections. Its incidence and intensity may be related to steroid composition. The purpose of this study was to determine whether betamethasone and methylprednisolone injections for trigger fingers have differing intensity of pain or incidence flare reaction.

METHODS

Patients with symptomatic trigger finger were recruited during their hand surgery visits. Patients were randomized into 2 treatment groups: betamethasone (40 mg) and methylprednisolone (6 mg) mixed with lidocaine 1%. Treatment group assignment was blinded to the patients and investigators. Visual analog scale pain measurements were taken prior to injection, 5 minutes postinjection, and daily thereafter for 7 days.

RESULTS

Sixty-four patients were randomized into the 2 treatment groups. Patients in the betamethasone group reported slightly higher baseline pain compared with the methylprednisolone group, but lower pain on day 1. None of the following days showed a statistically significant difference.

CONCLUSIONS

The incidence of flare and severe flare reactions of betamethasone injections for trigger finger management was roughly double that of methylprednisolone, but this difference was not statistically significant. Further studies are required to evaluate the relative course of nonflare postinjection pain for different corticosteroid injections for trigger finger injections.

Comparison of triamcinolone and methylprednisolone efficacy and steroid flare reaction rates after shoulder corticosteroid injection: a prospective interrupted time series study

BACKGROUND

A corticosteroid flare reaction is a well-described phenomenon that causes significant pain and dysfunction. The paucity of literature impedes decision making regarding which corticosteroid to use for shoulder injection. The purpose of this study was to compare methylprednisolone acetate (MPA) and triamcinolone acetonide (TA) injections in the glenohumeral joint and/or subacromial space in terms of efficacy and the incidence of steroid flare reactions.

METHODS

In this prospective, interrupted time series, parallel study, patients received injections in the glenohumeral joint and/or subacromial space. MPA and TA were used during 2 discrete 3-month periods. The injections consisted of 2 mL of lidocaine, 2 mL of bupivacaine, and 80 mg of either MPA or TA. Visual analog scale (VAS) pain scores were recorded immediately before injection; 1-7 days after injection; and 3, 6, and 12 months after injection. The primary outcome was the incidence of a steroid flare reaction, defined as a post-injection increase in the VAS score by ≥2 points. The secondary outcome was injection failure, defined as a post-injection VAS score greater than the baseline score or the need for another intervention. We used linear mixed models with a patient-level random intercept to identify the mean VAS score change for TA injections in the first week after injection.

RESULTS

MPA or TA shoulder injections were administered in 421 patients; of these patients, 15 received bilateral-joint injections whereas 406 received a single-joint injection, for a total of 436 injections (209 MPA and 227 TA injections). Pain scores in the first week after injection were available for 193 MPA and 199 TA injections. Significantly more patients in the MPA cohort reported flare reactions compared with the TA cohort (22.8% vs. 4.0%, P < .001) during the first week after injection. In the first week after injection, the mean VAS score of patients receiving TA injections was 1.05 (95% confidence interval, 0.47-1.63) lower than that of patients receiving MPA injections when adjusted for age, sex, race, pain type, surgeon type, and injection site. At 3 months, surveys for 169 MPA and 172 TA injections were completed, with no significant difference in the rate of injection failure for MPA vs. TA (42.6% vs. 36.1%, P = .224). Treatment failure rates were significantly higher for MPA than for TA at 6 months (78.44% vs. 62.5%, P < .001) but not at 12 months (81.18% vs. 81.42%, P = .531.) CONCLUSION: TA injections resulted in a >5-fold reduction in steroid flare reactions, with statistically superior 6-month efficacy rates, compared with MPA injections. This study supports TA as a more viable corticosteroid option for shoulder injection.

Prospective Evaluation of Pain Flares and Time Until Pain Relief Following Musculoskeletal Corticosteroid Injections

BACKGROUND

Corticosteroid injections are used ubiquitously within musculoskeletal medicine. One of the most common side effects is a postinjection pain flare, though little is known regarding this phenomenon.

HYPOTHESIS

Some risk factors are related to postinjection pain flare following an ultrasound-guided corticosteroid injection.

STUDY DESIGN

Prospective clinical research study.

LEVEL OF EVIDENCE

Level 2.

METHODS

Patients undergoing ultrasound-guided corticosteroid injections in an academic orthopaedic and sports medicine clinic were approached to participate. Patients completed a survey immediately following their injection and again 2 weeks later, asking them about their pain and side effects. A postinjection pain flare was defined as an increase in pain, as defined by the patient.

RESULTS

A total of 140 patients completed the entirety of the study, with 29 (20.7%) patients reporting a flare of pain. There was a significant effect of younger age on the development of a pain flare after the injection, estimated as 5.5% decreased odds of developing a flare per year of age (P < 0.01). Gender, injection location, body mass index (BMI), preinjection pain, and corticosteroid type had no contributing effect. When patients obtained relief following the corticosteroid injection, 60.4% had improved pain within 3 days, whereas over 93.7% obtained relief within a week.

CONCLUSION

Pain flares seem to affect approximately 1 in 5 patients. With increasing age, the likelihood of postinjection pain flare becomes less likely. Sex, injection location, BMI, preinjection pain, and corticosteroid type do not seem to significantly relate to an increase in pain following injection.

CLINICAL RELEVANCE

Corticosteroid injections are common procedures in the orthopaedic and sports medicine settings. Younger patients can be counseled on the higher likelihood of a pain flare following a corticosteroid injection.

Shoulder Impingement Syndrome

Shoulder impingement is the most common diagnosis for shoulder pain. Shoulder impingement syndrome has been scrutinized as a misleading "umbrella" term, due to its vague and nonspecific context. It is better subcategorized into subacromial, internal, and subcoracoid impingement. The evaluation and treatment algorithm for each is grossly similar. A thorough history, focused physical examination, and standard radiographs are the first steps. Advanced imaging with MRI or ultrasound may be useful. The mainstay of treatment includes physical therapy, anti-inflammatory medications, and injections. Surgical treatment is reserved for refractory cases, and includes decompression, debridement, and/or repair of injured structures.

Intra-articular Administration of Allogeneic Adipose Derived MSCs Reduces Pain and Lameness in Dogs With Hip Osteoarthritis: A Double Blinded, Randomized, Placebo Controlled Pilot Study

This study was conducted to investigate the therapeutic effect of allogeneic adipose-derived MSCs on dogs with hip osteoarthritis (OA). Twenty dogs with bilateral osteoarthritis of the coxofemoral (hip) joint, diagnosed by a veterinarian through physical examination and radiographs were randomly allocated into four groups. Group 1 served as a placebo control and were injected with 0.9% sodium chloride (saline) (n = 4). Group 2 were injected with a single dose of 5 million MSCs (n = 5). Group 3 received a single dose of 25 million MSCs (n = 6) and Group 4 received a single dose of 50 million MSCs (n = 5). Intra-articular administration of allogeneic MSCs into multiple joints did not result in any serious adverse events. The average lameness score of the dogs in the placebo control group (−0.31) did not show improvement after 90 days of intra-articular saline administration. However, the average lameness score of the all MSC-treated dogs was improved 2.11 grade at this time point (P < 0.001). Overall, sixty five percent (65%) of the dogs that received various doses of MSCs showed improvement in lameness scores 90 days after intra-articular MSC administration. Our results showed that intra-articular administration of allogeneic adipose derived MSCs was well-tolerated and improved lameness scores and reduced pain in dogs associated with hip OA. All doses of MSCs were effective. Subsequent studies with more animals per group are needed to make a conclusion about the dose response. The improved lameness effect was present up to 90 days post-injection. Serum interleukin 10 was increased in a majority of the dogs that received MSCs and that also had improved lameness.