Management of the Failed Arthroscopic Subacromial Decompression: Causation and Treatment

Os acromiale: a review of its incidence, pathophysiology, and clinical management

An os acromiale occurs when any of the primary ossification centres of the acromion fail to fuse with the basi-acromion. It is present in approximately 8% of individuals, and whilst the majority of these individuals are unaffected it can cause significant pain and disability. It can impact seemingly unrelated surgical intervention in the region such as subacromial decompression and reverse shoulder arthroplasty. A painful os acromiale can be both a diagnostic challenge, and difficult to manage. There remain a wide variety of surgical practices with variable outcomes achieved. We present an evidence-based discussion of the surgical techniques described to date in the literature, alongside a comprehensive review of the incidence and pathophysiology of os acromiale.

This review was written after a comprehensive analysis of the literature to date relating to os acromiale. Particular focus was given to material examining surgical management techniques, and the condition’s incidence across different population groups.

Open reduction and internal fixation using cannulated screws, or tension band wiring have superior outcomes in the literature in the treatment of symptomatic os acromiale. There may be a biomechanical advantage of combining the two techniques. Preservation of large anterior deltoid attachment is necessary, with consideration being given to the local blood supply. There is likely no additional benefit from iliac crest vs local bone grafting. Research in this area remains of a low evidence level with small samples sizes. Appropriately powered clinical research of a higher-level evidence methodology is needed in order to differentiate further in the choice of surgical intervention.

Cite this article: EFORT Open Rev 2019;4:525-532. DOI: 10.1302/2058-5241.4.180100

High prevalence of persistent pain 6 months after arthroscopic subacromial decompression and/or acromioclavicular joint resection

Purpose: The aims of this prospective study were to determine the prevalence of pain 6 months after arthroscopic subacromial decompression (ASD) and/or acromioclavicular joint resection (AC resection), to reveal causes of the pain, and to identify risk factors for persistent pain.

Methods: Preoperatively, patients were tested for their endogenous capacity to modulate pain and completed questionnaires concerning psychological vulnerability. Patients with pain 6 months after surgery were examined by an experienced orthopaedic surgeon to reveal any shoulder pathology responsible for the pain.

Results: Data from 101 patients were available for analysis 6 months after surgery. Thirty-six patients had persistent pain: 32 underwent examination by the surgeon who identified shoulder pathology in ten patients, but not in the remaining 22 in whom ongoing insurance case, unemployment, and a general tendency to worry were risk factors for persistent pain.

Conclusion: The prevalence of persistent pain 6 months after ASD and/or AC resection was 35.6% (95% CI 26.1–45.8%) and the proportion of patients with shoulder pathology was 9.9%. An association between ongoing insurance case, unemployment, general tendency to worry (t-STAI), and unexplained persistent pain 6 months after surgery was found.

Is fibromyalgia a cause of arthroscopic subacromial decompression failure?

Isolated arthroscopic subacromial decompression (IASD) is a widely used surgical procedure with high success rates. However, up to 25% of patients experience residual pain. It is unclear whether aberrant central nervous system processing of pain as described in fibromyalgia (FM) could have a detrimental effect on outcomes. To test this hypothesis, the authors conducted a retrospective case- control study of patients undergoing IASD.

MATERIAL AND METHODS

Between 2008 and 2015, 26 patients with preoperative diagnosis of fibromyalgia and an IASD procedure were identified. Six patients were lost to follow-up. Each fibromyalgia patient was matched with one control patient (n=20) recruited from the remainder with IASD. Outcomes were assessed by DASH score (Disability Arm Shoulder and Hand), Constant (CS), relative Constant score (rCS) and Visual Analogue Scale (VAS). Patient satisfaction was determined with a single 2-level question. Failure of the IASD was defined as persistent pain (VAS>3) at last follow-up.

RESULTS

The average age of the sample was FM/Control group 51/48, with a mean follow-up of 36/42 months respectively. Both groups exhibited significant clinical improvement in the pain VAS, DASH and rCS at final follow-up (P<.001) compared with the preoperative scores. Mean postoperative scores FM/Control group were: Constant 63.5/74 (P=.07), rCS 82/88 (P=.18), DASH 38.9/20.7 (P=.009), VAS 3.8/2.8 (P=.2). Eighty-five percent of patients in the control group were satisfied with the surgery compared with 55% in the FM group (P=.03). Failure of the procedure was 60% in the FM group, and 30% in the control group (P=.056).

CONCLUSIONS

Fibromyalgia can be considered a prognostic factor of a poor postoperative outcome after an IASD. However the clinical improvement experienced by these patients over their preoperative situation leads us to recommend their surgical treatment when indicated.

The effect of coracoacromial ligament excision and acromioplasty on the amount of rotator cuff force production necessary to restore intact glenohumeral biomechanics

HYPOTHESIS AND BACKGROUND

Coracoacromial ligament (CAL) excision and acromioplasty increase superior and anterosuperior glenohumeral translation. It is unknown how much of an increase in rotator cuff force production is required to re-establish intact glenohumeral biomechanics after these surgical procedures. We hypothesized that, after CAL excision and acromioplasty, an increase in rotator cuff force production would not be necessary to reproduce the anterosuperior and superior translations of the intact specimens.

METHODS

Nine cadaveric shoulders were subjected to loading in the superior and anterosuperior directions in the intact state after CAL excision, acromioplasty, and recording of the translations. The rotator cuff force was then increased to normalize glenohumeral biomechanics.

RESULTS

After CAL excision at 150 and 200 N of loading, an increase in the rotator cuff force by 25% decreased anterosuperior translation to the point where there was no significant difference from the intact specimen's translation. After acromioplasty (and CAL excision) at 150 and 200 N, an increase in the rotator cuff force of 25% and 30%, respectively, decreased superior translation to the point where there was no significant difference from the intact specimen's translation.

CONCLUSIONS

At 150 to 200 N of loading, CAL excision and acromioplasty increase the rotator cuff force required to maintain normal glenohumeral biomechanics by 25% to 30%.

CLINICAL RELEVANCE

After a subacromial decompression, the rotator cuff has an increased force production requirement to maintain baseline glenohumeral mechanics. Under many circumstances, in vivo force requirements may be even greater after surgical attenuation of the coracoacromial arch.

LEVEL OF EVIDENCE

Basic Science Study; Biomechanics.

Failed subacromial decompression. Risk factors

BACKGROUND

Arthroscopic subacromial decompression (acromioplasty) is widely held to be effective, although pain may persist after the procedure. The objective of this study was to evaluate the proportion of patients with residual pain (i.e., the failure rate) after isolated subacromial decompression and to look for predictors of failure.

MATERIAL AND METHOD

We conducted a retrospective multicentre study of 108 patients managed with isolated arthroscopic subacromial decompression between 2007 and 2011, for any reason. We excluded patients in whom surgical procedures on the rotator cuff tendons were performed concomitantly. Data were collected from the medical records, a telephone questionnaire, and radiographs obtained before surgery and at last follow-up. Failure was defined as persistent pain (visual analogue scale score>3) more than 6 months after surgery and at last follow-up.

RESULTS

The failure rate was 29% (31/108). Two factors significantly predicted failure, namely, receiving workers' compensation benefits for the shoulder condition and co-planing. Heterogeneous calcific tendinopathy and deep partial-thickness rotator cuff tears were also associated with poorer outcomes, but the effect was not statistically significant.

DISCUSSION

Co-planing may predict failure of subacromial decompression, although whether this effect is due to an insufficient degree of co-planing or to the technique itself is unclear. Nevertheless, in patients with symptoms from the acromio-clavicular joint, acromio-clavicular resection is probably the best option. Receiving workers' compensation benefits was also associated with treatment failure, as a result of well-known parameters related to the social welfare system.

CONCLUSION

Isolated arthroscopic subacromial decompression is effective in 70% of cases. We recommend the utmost caution if co-planing is considered and/or the patient receives workers' compensation benefits for the shoulder condition, as these two factors are associated with a significant increase in the failure rate.

LEVEL OF EVIDENCE

IV (retrospective study).

Arthroscopic subacromial decompression and predictors of long-term sick leave benefit and permanent benefits

BACKGROUND

Shoulder impingement syndrome is a common musculoskeletal complaint leading to reduced work ability. The aim of the present study was to identify predictors of long-term sick leave benefit and permanent benefits/permanently reduced work ability after arthroscopic subacromial decompression (ASD).

MATERIALS AND METHODS

The study included 615 individuals undergoing ASD (2003 to 2009). Data were linked to the 3 state registries concerning employment/benefits, medication, and industrial injuries. All individuals were monitored for 1 year, and 155 obtained complete 5-year follow-up. Risks were estimated in multivariate logistic regression models.

RESULTS

At 1 year after ASD, 16.6% were receiving sick leave benefit. The reduced multiple logistic regression model (odds ratio [95% confidence interval]) included painkillers (2.18 [1.37-3.46]), strong painkillers/opioids (3.78 [2.32-6.16]), and age (0.97 [0.94-0.995]). At 5 years after ASD, 35 (22.6%) were receiving permanent benefit. Predictors (odds ratio [95% confidence interval] were transfer income 2 years before ASD (3.44 [1.20-9.86]), use of opioids at any time during a 1-year period after ASD (24.80 [7.05-87.18]), or other work claims not due to shoulder disease (5.99 [1.34-26.72]).

CONCLUSION

A high percentage were receiving sick leave benefit 1 year after ASD, and nearly a quarter were receiving a permanent benefit 5 years after ASD. Medication before ASD was not a predictor of outcome. The strongest predictor of long-term sick leave benefit and permanent benefit was opioid use during the first year after ASD. This may indicate that pain after surgery may be an issue that needs further attention.

Is fibromyalgia a cause of failure in the treatment of a painful shoulder?

PURPOSE

This study aims to review the incidence of fibromyalgia in a cohort of patients who were treated for shoulder pain and address whether a concomitant fibromyalgia could have had detrimental effect on outcomes.

METHODS

The treatment of 286 consecutive patients for shoulder pain was reviewed.

RESULTS

Eighteen patients (6.3 %) were diagnosed as having fibromyalgia, but in 13 of them (72 %), the diagnosis was initially missed. Five patients received a total of 11 surgeries for treatment of the shoulder. At an average follow-up of 15 months (range 12-27), the average new Oxford shoulder score (OS score) was 49 % (range 6-87 %). The average physical component of the Short-Form-12 Healthy Survey (SF-12) was 36 (range 21-55), and the mental component 30 (range 15-46). The Summary Outcome Determination score (SOD score) was 1.3 (range-3 to 6).

CONCLUSIONS

Fibromyalgia occurs relatively frequently in patients who complain of shoulder pain and it can be a cause of failure in the treatment of concomitant painful shoulder conditions.