Shoulder & Elbow

Lateral acromioplasty in rotator cuff repairs

Subacromial decompression is a hot topic in arthroscopic shoulder surgery at present, following the Can Shoulder Arthroscopy Work? (CSAW) trial,¹ which reported that surgical groups had superior outcomes for shoulder pain and function, although this difference was not clinically significant. Recently, attention has turned to the importance of the morphology of the lateral acromion and its role in mechanical subacromial impingement. It has previously been suggested that a critical shoulder angle (CSA) of more than 34° is associated with rotator cuff tears. However, although widely quoted, the evidence for this is not yet strong. Some surgeons advocate removal of this lateral bone when performing a rotator cuff repair, but, while further research disentangles the multitude of factors that affect the outcome of a rotator cuff repair, it is important to know if this subacromial decompression is appropriate or not. This study from Zürich (Switzerland) reports the outcomes of 49 consecutive patients, all with a high CSA, who underwent an arthroscopic rotator cuff repair for a degenerative, full-thickness supraspinatus tear.² All of the patients underwent a lateral acromioplasty that reduced their CSA from a mean of 37.5° to 33.9° postoperatively; no patients underwent an anterior acromioplasty. At a mean follow-up of 30 months, the mean Constant shoulder score had increased from 59 to 74 points, and seven repairs had failed. Interestingly, the postoperative CSA was significantly larger in failed than in healed repairs. Patients who had a healed cuff repair and a CSA corrected to 33° or less had 25% more abduction strength than patients with a healed cuff and a CSA of 35° or more. Importantly, the deltoid integrity was unaffected on follow-up MRI scanning, with no cases of dehiscence, atrophy, or other complications of this procedure. The authors conclude that a lateral acromioplasty is safe to perform and that large, insufficiently corrected CSAs are associated with poorer outcomes in cuff repair. While further research is certainly required with respect to improving outcomes, it is useful to know that such procedures can be undertaken safely.

Glenosphere lateralization in reverse shoulder arthroplasty

Another current talking point among shoulder surgeons is the management of the subscapularis when performing a reverse total shoulder arthroplasty. Conventional wisdom was that repair was necessary to restore the force-couple with the posterior cuff, thereby balancing the prosthesis and preventing instability, while also preserving the power of internal rotation. The reverse shoulder, however, is a non-anatomical prosthesis and, as more recent designs are evolving from a traditional Grammont design towards prosthesis requiring increased lateralization of the components, the excursion required of subscapularis to reach its insertion is therefore increasing. Cadaveric studies have shown that this increases the force required by the posterior cuff and deltoid to elevate the arm, increases the joint reaction forces, and may restrict external rotation. This group from Virginia, New York, and Minnesota (USA) therefore sought to retrospectively review their patients, and to analyze the effects of lateralization and subscapularis management.³ Their study is based on the results of 109 patients and their outcomes. Participants were included in the study who underwent primary reverse shoulder arthroplasty and had both baseline and minimum two-year postoperative American Shoulder and Elbow Surgeons (ASES) shoulder scores. Like all cohort studies, there was variation in practice; of the 109 participants, 71 had undergone a subscapularis repair and 38 had not. Patients were stratified according to the presence of a subscapularis repair and then subgrouped according to lateralization of the glenosphere component. On an individual basis, subscapularis repair and lateralization had no effect on ASES scores but had a significant effect in combination. Overall, patients with a lateralized glenosphere and a repaired subscapularis had significantly less improvement in ASES scores than both those without lateralization and those without subscapularis repair. Importantly, they reported no increase in their dislocation or instability rate. Although this study has a number of methodological limitations, the results stimulate debate. Here at 360 we look forward to prospective studies that incorporate more outcome measures, including range of motion. It is also important to remember that there are many prostheses on the market, with variable lateralization of both the glenoid and humeral components, and results may not be generalizable between them.

Operative or nonoperative? The evidence for treatment of full-thickness rotator cuff tears

Rotator cuff pathology is common and there are many people at large in the community with asymptomatic cuff tears. Some would argue that the common ‘shoulder arthropathy’ seen in the elderly is almost a ubiquitous process. Others would argue that most symptomatic tears are traumatic and, as such, there is a specific pathology here. Many patients do experience symptoms and do present for treatment, but there is not a firm consensus on how this large volume of patients should be managed. This group from Washington DC (United States) performed a systematic review and meta-analysis of randomized controlled trials comparing operative and nonoperative management of full-thickness, atraumatic rotator cuff tears.⁴ Despite an extensive search, there were only three trials meeting their inclusion criteria, with 269 patients having a minimum one-year follow-up; the mean age of these patients was between 59 and 65 years. The Constant score and visual analogue scale (VAS) for pain were selected for comparison, as these were reported in all included studies. Both Constant and VAS scores were significantly improved at one year, with mean differences of 5.64 and -1.08, respectively. However, neither of these differences met the minimally clinically important difference values. In common with most studies of cuff treatments, there are methodological differences between the included studies, which may potentially have more of an impact than one might anticipate. For example, one study included only supraspinatus tears and another had no limit on cuff tear size. Acromioplasty and biceps management were also left to the discretion of the treating surgeon. The nonoperative management was not uniform either, with only one study having a standardized physical therapy protocol. The number of corticosteroid injections in this group was variable too. Advocates for repair would point to the opportunity cost of failure to repair with respect to the halting of tear progression, and the development of fatty infiltration and muscle atrophy. From this study and the evidence synthesis it provides, however, the answer is still not clear. In common with the majority of systematic reviews and meta-analyses, all the authors can do is offer the now familiar advice that more high-quality studies with longer follow-up are required.

Is arthroscopically assisted latissimus dorsi tendon transfer feasible for irreparable posterosuperior rotator cuff tears?

The management of irreparable rotator cuff repairs is a matter of great debate within the shoulder community, with many techniques on offer, ranging from extensive debridement through the varieties of ‘patches’ and even extending to arthroplasty. One option, although not widely in use, is that of a latissimus dorsi tendon transfer. This is thought to act in a number of ways, including: as a spacer between the humeral head and the acromion; as a depressor of the head, which allows the recreation of the fulcrum for elevation; and by rebalancing the force-couples acting within the shoulder, which acts to improve remaining cuff function. However, the procedure is lengthy, complex, and invasive, and is a challenge for the occasional surgeon. A surgeon from Fuki (Japan) sought to evaluate his personal results and learning curve with an arthroscopically assisted technique for latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears.⁵ In this clinical report, a partial repair of the remainder of the posterior cuff was performed arthroscopically in all patients, followed by arthroscopic assistance to create the tunnel for the latissimus transfer. The tendon itself was harvested through an axillary mini-open incision and passed into position with arthroscopic assistance. The reported series included the outcomes of 30 patients with a mean follow-up of 34 months. Significant improvements were seen in a range of outcome measures, with University of California, Los Angeles (UCLA) scores (from 16 preoperatively to 29 postoperatively), active forward elevation (improved from 105° to 149°), and active external rotation (improved from 22° to 32°) all superior at nearly three years of postoperative follow-up. After statistical transformation, a linear correlation was seen between operative time and cumulative number of cases, indicating improved surgical efficiency with experience. The mean operative time itself was 145 minutes. While this is clearly not an operation for the occasional shoulder surgeon, the results here are promising for an otherwise very challenging-to-treat pathology. It appears from this data that those surgeons committing to performing a sizeable number should expect a long learning period for this technically demanding operation, which does, however, seem to improve outcomes in a select cohort.

Polyethylene: the glenoid of choice in young patients

The treatment of osteoarthritis of the shoulder in patients under 60 years old is controversial, due to high functional demands. Given the patient’s expected lifespan, the longevity of arthroplasty presents an ongoing difficulty. A particular challenge in this group is revision of the glenoid; the components can loosen, leading to extensive bone loss and difficult revision. The optimal type of glenoid fixation in these patients is not entirely clear, and surgeons must take into account the more likely need for revision surgery in this group of patients. These authors from Nice, Toulouse, Brest, and Lyon (France) and Wahroonga (Australia) examined their results of 69 consecutive anatomic total shoulder arthroplasties (46 using a cemented polyethylene component and 23 using a cementless metal-backed component) in patients aged under 60 years.⁶ These subgroups were comparable in terms of demographics, including age, gender, preoperative function, mobility, and premorbid glenoid erosion. One of the strengths of this series was the long mean follow-up of 10.3 years. Overall, 26 patients (38%) underwent revision surgery in this time. This was significantly more likely in the metal-backed group (16 of 23 patients, 70%) compared with the polyethylene group (ten of 46 patients, 22%). Survival rates for the polyethylene component at 12 years’ follow-up was 74%, whereas for metal-backed components this was significantly (and potentially catastrophically) lower at 24%. In the polyethylene group, the reason for revision was predominantly glenoid loosening, whereas indications for revision in the metal-backed group were polyethylene wear leading to metal-on-metal contact, instability, and insufficiency of the rotator cuff. It was also identified that Walch B2 glenoids had an adverse effect on the survival of the metal-backed components. Difficulties with two of the theoretical arguments for using a metal-backed glenoid were also highlighted by the authors. These include the ease of exchange of a worn polyethylene insert, which they found was often precluded by loosening, glenoid bone loss, or damage to the tray, and the ease of revision, which in the authors’ experience was often precluded by osteolysis and bone loss. The metal-backed glenoid is therefore not in favour with the authors. It should be noted that some designs have been withdrawn from the market due to high revision rates and that evolutions in design have taken place. However, the authors’ conclusion – that they will be using a cemented polyethylene component until better options are available – seems sound to us here at 360.

Body mass index and rotator cuff repair

We are in the midst of an obesity epidemic, and the challenges that this represents in orthopaedic surgery are significant. If we are to commit obese patients to surgeries in which the risks of anaesthetic are higher, we must be sure that the benefit of the procedure justifies this risk. Multiple previous studies have found conflicting conclusions about the influence of obesity on outcomes after rotator cuff repair. Although there is already a sizeable volume of literature available, this paper from a group from Ann Arbor, Michigan (USA) certainly has something to add to the debate.⁷ The study team hypothesized, not unreasonably, that obesity would lead to adverse functional outcomes and more complications. The authors report their retrospective series of rotator cuff repairs, having reviewed their single-centre database for patients fulfilling the inclusion criteria. They were able to analyze the outcomes of 213 arthroscopic rotator cuff repair of full-thickness tears, comparing the results of patients with a body mass index (BMI) of over 30 and under 30 with non-obese patients. Remarkably, in this data set, 40% of patients had a BMI in this higher range. Baseline characteristics of the two groups were compared, showing no significant difference in other possible confounders, such as smoking rates or diabetes. The data was collected for patients operated on over a three-year period; a minimum final three-year follow-up of outcome scores was required. Data analysis, including regression analyses, was performed. When controlling for covariates, the obese and non-obese groups had no significant difference at baseline and at three years in their Western Ontario Rotator Cuff, American Shoulder and Elbow Surgeons, or visual analogue scale pain scores. Furthermore, there was no difference in the incidence of postoperative complications. Obese patients were more likely to require an inpatient hospital stay, but this was booked before surgery in the majority of patients, with sleep apnoea being the most common reason. There are weaknesses in this study, and the results in the extremely obese (those with a BMI over 40) were not subanalyzed. A prospective study would therefore be helpful but, at present, there seems no specific surgical issue that would prevent surgery being offered, aside from the fact that an inpatient stay should be anticipated.

Reverse shoulder arthroplasty following fracture of the proximal humerus

Is nonoperative management of partial distal biceps tears really successful?

Partial distal biceps ruptures are often managed nonoperatively but the literature base is sparse regarding the success of this approach and the outcomes of those who undergo delayed repair. We were therefore pleased to see this study of a large cohort of patients reported by a team from Philadelphia (USA).⁹ They retrospectively identified 132 patients presenting to their unit with a partial distal biceps rupture treated in their institution. Given the retrospective nature of the design, it is not surprising that the authors were only able to successfully contact 74 of these patients with an outcome survey. In this population, 56% of the contacted patients who tried an initial nonoperative course (34 of 61 patients) ultimately underwent surgery, meaning that 27 patients had completely nonoperative treatment, 34 patients failed nonoperative management and underwent delayed repair, and 13 patients underwent immediate surgery after their injury. There was no difference in satisfaction scores between patients who tried a nonoperative course before surgery and those who underwent immediate surgery. The only preoperative factor identified as being predictive of having a delayed repair was an MRI-diagnosed tear of greater than 50% of tendon width. Perhaps most importantly in this study, there were no differences in complication rates between those patients who underwent acute and delayed repairs. This study is useful for the initial counselling of these patients and they can be advised that, although there is a sizeable chance that they will fail nonoperative management, there is no lost opportunity and a delayed repair is not likely to incur a disadvantage. Higher-demand patients and those with a tear width over 50% should also be advised of their increased risk of need for delayed repair.