Key points

Introduction

In 1972, Neer first described acromioplasty and reported on its utility in treating chronic impingement syndrome. He postulated acromial morphology as the initiating factor leading to dysfunction of the rotator cuff and eventual tearing. This tenet is the basis for the extrinsic theory of rotator cuff degeneration and has had a profound impact on surgical practice, with several investigators advocating for concomitant acromioplasty during surgical repair of rotator cuff tears. According to Neer’s original description of the acromioplasty procedure, the anterior edge and undersurface of the anterior acromion is removed as well as the coracoacromial ligament. Since then, various modifications have been proposed. For example, in 1987, Ellman described an arthroscopic technique to accomplish coracoacromial ligament release, resection of the anterior acromion undersurface, and bursal débridement, which he termed, arthroscopic subacromial decompression (SAD) . McCallister and colleagues as well as Matsen and Lippitt described a “smooth and move,” which involves an extensive bursectomy and smoothing of the undersurface of the acromion without altering acromial morphology. A potential complication of acromioplasty is postoperative avulsion of the deltoid origin due to its weakening by the procedure. In order to avoid this, the smoothing procedure does not involve resection or release of the coracoacromial ligament.

In contrast to the extrinsic theory, the intrinsic theory of rotator cuff pathology proposes that abnormalities of the rotator cuff occur secondary to intratendinous degeneration or tendinosis, which in turn results when eccentric tensile overload occurs at a rate greater than the ability of the cuff to repair itself. According to this perspective, acromioplasty as a form of treatment fails to address the aforementioned primary problem of intratendinous degeneration.

Recent epidemiologic studies have clearly demonstrated a rapid rise in the number of acromioplasty procedures performed in the United States on an annual basis. Vitale and colleagues reviewed the records from the New York Statewide Planning and Research Cooperative System (SPARCS) ambulatory surgery database from 1996 to 2006 and the American Board of Orthopaedic Surgery (ABOS) database from 1999 to 2008 to identify patients who had an acromioplasty. The investigators found a 254.4% increase in the SPARCS group versus 142.3% in the ABOS group for the number of acromioplasties over their respective time-periods. Yu and colleagues reviewed the records of 246 patients identified from the Rochester Epidemiology Project, cataloging medical records of residents in Olmsted County, Minnesota, who had an isolated acromioplasty performed between 1980 and 2005. They found a 575.8% increase over this time period, further demonstrating the widespread popularity of this procedure. Although there are many possible explanations for the observed increase in the annual number of acromioplasties, there is a need to evaluate whether this observed rise is associated with sound clinical indications supported by high-level clinical evidence.

At the present time, the 2 most common indications for performing an acromioplasty are subacromial impingement refractory to nonoperative care and during arthroscopic or open rotator cuff repair. The purpose of this article is to summarize and review the current evidence regarding the efficacy of acromioplasty both for subacromial impingement syndrome (SAIS) and during arthroscopic repair of rotator cuff tears.

Introduction

In 1972, Neer first described acromioplasty and reported on its utility in treating chronic impingement syndrome. He postulated acromial morphology as the initiating factor leading to dysfunction of the rotator cuff and eventual tearing. This tenet is the basis for the extrinsic theory of rotator cuff degeneration and has had a profound impact on surgical practice, with several investigators advocating for concomitant acromioplasty during surgical repair of rotator cuff tears. According to Neer’s original description of the acromioplasty procedure, the anterior edge and undersurface of the anterior acromion is removed as well as the coracoacromial ligament. Since then, various modifications have been proposed. For example, in 1987, Ellman described an arthroscopic technique to accomplish coracoacromial ligament release, resection of the anterior acromion undersurface, and bursal débridement, which he termed, arthroscopic subacromial decompression (SAD) . McCallister and colleagues as well as Matsen and Lippitt described a “smooth and move,” which involves an extensive bursectomy and smoothing of the undersurface of the acromion without altering acromial morphology. A potential complication of acromioplasty is postoperative avulsion of the deltoid origin due to its weakening by the procedure. In order to avoid this, the smoothing procedure does not involve resection or release of the coracoacromial ligament.

In contrast to the extrinsic theory, the intrinsic theory of rotator cuff pathology proposes that abnormalities of the rotator cuff occur secondary to intratendinous degeneration or tendinosis, which in turn results when eccentric tensile overload occurs at a rate greater than the ability of the cuff to repair itself. According to this perspective, acromioplasty as a form of treatment fails to address the aforementioned primary problem of intratendinous degeneration.

Recent epidemiologic studies have clearly demonstrated a rapid rise in the number of acromioplasty procedures performed in the United States on an annual basis. Vitale and colleagues reviewed the records from the New York Statewide Planning and Research Cooperative System (SPARCS) ambulatory surgery database from 1996 to 2006 and the American Board of Orthopaedic Surgery (ABOS) database from 1999 to 2008 to identify patients who had an acromioplasty. The investigators found a 254.4% increase in the SPARCS group versus 142.3% in the ABOS group for the number of acromioplasties over their respective time-periods. Yu and colleagues reviewed the records of 246 patients identified from the Rochester Epidemiology Project, cataloging medical records of residents in Olmsted County, Minnesota, who had an isolated acromioplasty performed between 1980 and 2005. They found a 575.8% increase over this time period, further demonstrating the widespread popularity of this procedure. Although there are many possible explanations for the observed increase in the annual number of acromioplasties, there is a need to evaluate whether this observed rise is associated with sound clinical indications supported by high-level clinical evidence.

At the present time, the 2 most common indications for performing an acromioplasty are subacromial impingement refractory to nonoperative care and during arthroscopic or open rotator cuff repair. The purpose of this article is to summarize and review the current evidence regarding the efficacy of acromioplasty both for subacromial impingement syndrome (SAIS) and during arthroscopic repair of rotator cuff tears.

Acromioplasty for management of subacromial impingement syndrome

Rotator cuff disease with subacromial impingement has been described in 3 stages: stage 1, acute inflammation and either tendonitis or bursitis; stage 2, chronic inflammation with or without degeneration; and stage 3, full rupture of the cuff. Subacromial impingement occurs when the normal sliding mechanism, while lifting the arm, is disrupted by compression of the soft tissues between the coracoacromial arch and the greater humeral tuberosity. Patients complain of pain over the anterolateral shoulder, radiating down the lateral humerus. They also report pain when laying on the affected extremity, oftentimes awakening them at night. Activities of daily living, such as combing hair or reaching for an item in a cupboard, are painful. Neer and Hawkins tests are 2 provocative examination maneuvers that are highly sensitive but not specific to subacromial impingement. Combined, they have a negative predictive value of 90%.

Initial conservative management for SAIS includes nonsteroidal antiinflammatory drugs, physical therapy (PT), and corticosteroid injections. Few studies have looked at each of these modalities separately to determine their respective efficacy. Desmeules and colleagues performed a systematic review evaluating the effectiveness of PT in treating impingement syndrome. In their review of 7 studies, they found that evidence did not support PT as an effective modality. More recently, however, Hanratty and colleagues performed a systematic review and meta-analysis that included 16 studies (4 high quality, 7 medium quality, and 5 low quality) regarding PT in patients with subacromial impingement. They concluded that there was strong support for exercise in decreasing pain and improving function at short-term follow-up. There was also moderate evidence that exercise results in short-term improvement in mental well-being and a long-term improvement in function.

The current belief is that SAD is the gold standard surgical treatment. Several studies, however, have brought this into question. Brox and colleagues (level 4, grade B-C) compared the outcomes of patients with stage 2 impingement, dividing them into 3 groups—PT, SAD, and placebo. They found that PT and SAD were each better than placebo but found no difference between the PT and SAD groups at 6 and at 30 months. Haahr and colleagues (level 4, grade C) performed a randomized control study with 1-year follow-up comparing exercise to SAD. They found no statistically significant difference in the mean change in Constant scores between groups at 3, 6, and 12 months or in the Project on Research and Intervention in Monotonous Work (PRIM) scores (aggregated pain and dysfunction score) at 12 months. Rahme and colleagues (level 4, grade C) compared open SAD to a physiotherapy regimen. At 6 and 12 months, there was no statistically significant difference between groups. Thus, these 3 studies, albeit of low quality, found no difference between SAD and conservative therapy.

More recently, Ketola and colleagues (level 1) performed a 2-year randomized controlled trial (RCT) comparing a supervised exercise program with arthroscopic acromioplasty followed by a supervised exercise program, with the main outcome measure self-reported pain on a visual analog scale (VAS). Although both groups showed an improvement, there was no statistically significant difference in the degree of improvement between groups on the VAS nor in secondary outcome measures of disability, pain at night, shoulder disability questionnaire score, number of painful days, and proportion of pain-free patients. The investigators note, however, that it seemed the operative group recovered faster in all parameters when assessed from the initiation of the treatment. At this time, the evidence does not seem to support acromioplasty over therapy and exercise and places in question its status as the gold standard of treatment of SAIS.

A study by Magaji and colleagues (level 3) investigated the efficacy of SAD in patients with SAIS refractory to conservative therapy for 6 months. They found that patients with all of the following 4 criteria were excellent candidates for SAD: pain in the shoulder with overhead activity or in the midarc of abduction; a repeatedly positive Hawkins test; temporary pain relief (minimum 2 weeks) after subacromial steroid injection; and radiologic evidence of impingement with sclerosis, cysts, or osteophytes at the greater tuberosity and acromion. Perhaps the key to obtaining successful outcomes with surgical intervention lies in using strict criteria for identifying appropriate patients for SAD—that is, patients who have failed a prolonged nonoperative regimen for a minimum of 6 months, including supervised physical therapy, injections, and activity modification.