Superior capsular reconstruction with a porcine xenograft

Abstract

Background

Short-term clinical and radiographical results after surgical treatment of irreparable rotator cuff rupture with superior capsular reconstruction. A prospective study to examine the functional outcome and radiographical shoulder findings after superior capsular reconstruction using a porcine extracellular matrix dermal graft.

Methods

Clinical results were evaluated using the Constant Score and Western Ontario Rotator Cuff Index over a 2-year follow-up period. Twenty-seven of 29 operated shoulders had magnetic resonance imaging of the injured shoulder after one year with a qualitative radiographic evaluation of graft integrity.

Results

A total of 28 patients were operated with 29 superior capsular reconstructions. Over a 5-year period, 27 patients were included for a 2-year follow-up in which 24 patients completed. The mean age was 59 years at the time of surgery. At the final follow-up for 24 patients (mean 24 months) the mean Constant Score had improved from an average of 25.3 points to 56.5 points. The mean Western Ontario Rotator Cuff Index had increased from a percentage average of 30.2%-59.4%. Five out of 27 grafts were ruptured on follow-up magnetic resonance imaging. The clinical failure rate was 6 patients out of 28.

Conclusions

No certain correlation between functional outcome scores and graft durability was found. No certain correlation between functional outcome and single tendon vs. 2 tendon defects was proven. There was a positive correlation between an inferior functional outcome and advanced stages of glenohumeral arthropathy. This study suggests that a superior capsular reconstruction can yield results that are comparable to other known salvage treatment options in patients with large-to-massive, irreparable rotator cuff defects with no significant cuff tear arthropathy. With these results, selected patients can be considered for treatment with superior capsular reconstruction rather than reverse shoulder arthroplasty, débridement, or tendon transfer.

A chronic irreparable defect in the superior rotator cuff is associated with pain and a reduced shoulder function.^2,38 In many irreparable superior cuff tears, only a rigid tendon remnant is found at the glenohumeral joint line with significant fatty degeneration and muscle atrophy of the rotator cuff muscle below the tangent line.^17,19,31 This leaves a large defect in the upper part of the rotator cuff which contributes to an unstable and superiorly displaced glenohumeral fulcrum resulting in painful impaction of the humeral head against the undersurface of the acromion during shoulder abduction.^23,31 Often, surgical release, tension free reinsertion, and closure of such defects are impossible and such patients are left with significant symptoms of pain, and loss of strength, and active range of motion (AROM). Patients under 70 years often attain less satisfying results with physiotherapy.^{8,9,21,23,31,38}

Current surgical options are débridement and smoothening of the underside of the acromion without violating the coracoacromial ligament, tenotomy of the long head of the biceps, or partial rotator cuff repair to reduce the size of a tendon defect. Surgical procedures such as transposition of the latissimus dorsi tendon or a reverse shoulder arthroplasty (RSA), even though the glenohumeral cartilage is intact, have been used.^{1,7,15,23,28,29} In recent years, several publications on superior capsular reconstruction (SCR) have emerged and some studies show improvements in attaining a stable glenohumeral articular fulcrum.^{7,10,13,27,26,33,35}

Various types of graft material have been used.^11,22,37 The porcine graft is cheaper than a human dermal graft, the price of a porcine xenograft in the authors’ country being considerably less than for a human allograft. In a recent study, the authors presented promising results after SCR using a porcine dermal extracellular matrix xenograft (Extracellular Matrix Surgical Mesh: Arthrex DX Reinforcement Matrix; Arthrex, Naples, FL, USA) in a series with relatively few patients included.³⁵ Our hypothesis in this prospective study was to examine if the outcome following SCR with an extracellular matrix porcine xenograft in patients with a chronic irreparable superior or posterosuperior defect in the rotator cuff in a larger series of patients would significantly increase function and limit pain. Results with functional scores and postoperative magnetic resonance imaging (MRI) scan findings are presented.

Materials and methods

During a 5-year period from October 2015 to December 2020, we used the Extracellular DX Reinforcement Matrix Mesh for patients not older than 70 years of age with a chronic irreparable superior or posterosuperior tendon defect which included either a total defect of the supraspinatus tendon or a larger defect including the supraspinatus as well as the infraspinatus tendons. There were no preoperative radiographical changes more severe than acetabularization and no narrowing of the glenohumeral joint.¹⁹ The extent of a tendon defect and its irreparability was verified either from a prior shoulder arthroscopy that documented the defect and irreparability or from an MRI scan displaying a retracted rotator cuff remnant, Goutallier grade 3 or 4 fatty degeneration and posterosuperior muscle atrophy with a positive tangent sign.^19,33,35

All patients had failed to improve following a 3 month training program to strengthen the anterior deltoid muscle and remaining posterior rotator cuff supervised by a physiotherapist.^24,30,32 The patients had considerable pain and functional impairment and desired a surgical treatment option. None other than the 3 authors assessed the patients. Included patients had no history of alcohol or drug abuse, mental inhibition, and stated they would be compliant with the rehabilitation program and follow-up scheme.

A total of 31 patients were eligible for an SCR. In 2 patients, a closure of the entire defect could be performed. These patients were not included in this study, leaving 29 patients who had an SCR. During the follow-up period, one patient died within 6 months after the operation and was excluded. Another patient with a two-tendon defect developed a subacute postoperative infection where the graft had to be removed 10 days after the index operation as an emergency procedure. Therefore, this patient was excluded, leaving 27 patients to be followed up for more than a year, see the flow chart in Figure 1.

Figure 1.

Flow chart detailing patient selection, drop out patients, and patients who completed the 2-year follow-up period. MRI, Magnetic resonance imaging.

The operation was performed either purely arthroscopically (28 patients) or arthroscopically with mini-open lateral fixation of the graft through a minor deltoid split (one patient). Before a xenograft was implanted, all tendon remnants were released and it was examined whether a tension free tendon reinsertion could be performed. All patients were scheduled for a prospective follow-up at 6, 12, and 24 months with functional outcome scores and an MRI scan, see Table I, in order to evaluate graft durability and glenohumeral joint stability, see Figures 2 and 3. If an MRI scan was performed preoperatively, this was done maximally 6 months prior to the operation.

Table I.

Outcome evaluation plan.

	Preoperative	Postoperative, 6 mo	Postoperative, 12 mo	Postoperative, 24 mo
MRI scan	x and/or prior arthroscopy		x
Constant Score	x	x	x	x
WORC Index	x		x	x

MRI, Magnetic resonance imaging; WORC, Western Ontario Rotator Cuff.

Figure 2.

A postoperative magnetic resonance imaging scan slide of a right shoulder at 1 year follow-up illustrating the intact xenograft positioned between a superiorly positioned humeral head and the acromion.

Figure 3.

A postoperative magnetic resonance imaging scan slide of a left shoulder at 1 year follow-up illustrating the intact xenograft positioned between a superiorly positioned humeral head and the acromion.

All written surveys were given in at each visit to the outpatient clinic. When calculating strength for the Constant Score (CS), this was measured at 90° of scaption over a period of 5 seconds and repeated 3 times using the best score. If the arm could not be abducted to 90°, strength was measured in a position of maximal abduction.^9,18 An Isobex isometric dynamometer (Cursor, Bern, Switzerland) was used. Thus, AROM in flexion and abduction was measured for all patients and CS was calculated for both arms for comparison. The Western Ontario Rotator Cuff (WORC) Index reflects the patient’s own perception of changes in health status, and thus is an indicator of the success of treatment. The questionnaire contains 21 items each with a visual analog response option for the following 5 domains: pain and physical symptoms (6 questions), sport and recreation (4 questions), work (4 questions), lifestyle function (4 questions), and emotions (3 questions). The index values are reported as a percentage reflecting shoulder function.³⁵ The WORC index offers a subjective evaluation of quality of life following treatment and we found it to be useful as a supplement to the CS.

A power calculation was made by comparing the preoperative CSs and WORC indices, respectively, of the 24 patients that completed the follow-up period to their scores at 2 years follow-up. Therefore, a paired samples t test was used. P values were 2-tailed with an alpha-coefficient of 0.05, which indicates significance. When power was set at 80%, the effect size of the CSs was 1.47 and for WORC indices, the effect size was 1.41. Thus, the measured effect sizes reflect a uniquely positive effect on our results following the SCR procedure. With 24 patients completing the follow-up period, the study was adequately powered.

Operative technique and after treatment

The patients were operated by a team of 3 surgeons, 2 surgeons per procedure, the first author being the primary surgeon in all cases. The surgical procedure was performed according to the recommendations published by Hirahara²¹ and Burkhart⁵ At first, any infraspinatus tendon rupture was released and repaired with anchor fixation if possible. This was done in 12 of 19 patients. In 7 out of 19 cases, the infraspinatus tendon was irreparable. In the remaining 10 out of 29 cases, an irreparable defect of the supraspinatus tendon was found.

When handling the xenograft, the 1.5 mm thick graft was folded into 2 layers and whipstitched on the remaining 3 sides with a nonresorbable suture, FiberWire 0 (Arthrex, Naples, FL, USA). Thus, the graft was 3 mm in thickness. To avoid brittleness of the material, glue was not applied between the layers. Soft anchors were used medially on the glenoid and the medial anchor sutures were threaded extracorporeally, pulling the graft into place superiorly on the glenoid neck as a single-row fixation. The lateral fixation was then performed using a retrograde suture passing device and completed as a double-row fixation using the Speedbridge anchor system (Arthrex, Naples, FL, USA). One or more nonresorbable convergence sutures were then placed between the graft and the posterior cuff tissue. The graft medially covers a sagittal area from the base of coracoid process to the posterior cuff and laterally from the top of the intertubercular sulcus to the posterior cuff. Any torque of the graft was minimized to avoid graft rupture and the graft was held manually to avoid damage from metal instruments. The graft was secured with the arm in neutral position at the side of the chest wall, which entails some abduction of the upper arm due to the size of the body trunk but with no additional abduction.

An abduction sling was used for 4 weeks. The shoulder was passively mobilized for the first 6 weeks postoperatively, after which the patients started AROM. The shoulder was unloaded for 4 months. The patients were advised that external loading was not the aim of the operation. The patients were referred to rehabilitation supervised by local municipal physiotherapists near the patients’ home. The rehabilitation program was designed according to the recommendations by Burkhart.⁵ At follow-up, clinical results were evaluated using the CS and WORC Index. Postoperative MRI scans were evaluated by 2 authors, AU and MR, with each author separately describing the integrity of the graft, any superior displacement of the humeral head, and the thickness of the graft. A 100% interobserver consistency was found in their evaluation of graft integrity.

Results

A total of 29 shoulders were operated on in 28 patients. There were 23 men and 5 women. The mean age was 59 years (range, 45-70) at the time of surgery. Of which, 19 shoulders had a total rupture of the supraspinatus with a total or subtotal infraspinatus tendon rupture and 10 shoulders had an isolated total rupture of the supraspinatus tendon. Furthermore, 24 patients completed the follow-up period, 5 patients did not. Of those 5 patients, one with a two-tendon defect developed a subacute postoperative infection where the graft had to be removed as an emergency procedure. Later on, this patient had a second successful SCR procedure. One patient died one year after his operation. These 2 patients did not have postoperative MRI scans. Thus, the remaining group included 27 patients who all had an MRI scan approximately 12 months after the operation. Three patients with a two-tendon defect had significant pain and deteriorating function during the first year following SCR. Of these patients, one had a total nontraumatic rupture of the graft, another had a large subtotal rupture, and the third patient had an intact xenograft on MRI scans at the 1-year follow-up visit. All 3 had developed significant glenohumeral arthropathy, that is, Hamada stage >3, and were offered a RSA which was implanted 12, 15, and 16 months after the index procedure.

Twenty-four patients completed their follow-up schedule, 9 with a one-tendon defect and 15 with a two-tendon defect. Of the two-tendon defects, 9 infraspinatus tendon ruptures were repaired, whereby the implanted graft covered a one-tendon defect. In the remaining 6 patients, the defect thus included both tendons. All 24 patients were available at all times of follow-up for a clinical and radiologic review to evaluate the effect of the operation. The mean follow-up period was 24 months (range, 23-32).

On follow-up MRI scans or during a secondary operative procedure we found 3 total and 2 large subtotal graft ruptures out of 27 grafts (19%), 2 on the glenoid side and 3 on the humeral side. In 19 out of the remaining 22 patients with an intact graft the humeral head was positioned superiorly (86%) toward the undersurface of the acromion. The graft thickness was 3-4 mm in all cases. No arthropathy with joint narrowing or other radiographical features of progressive joint degeneration was seen on follow-up MRI scans in the group of 24 patients that completed the follow-up period.

At the final follow-up, the mean CS and WORC Index values for the group of 24 patients that completed the follow-up period had increased from 25 (range, 10-56) to 57 (range, 15-82) and from 30% (range, 8%-51%) to 59% (range, 22%-87%). Average subscores of pain and elevation from the CS improved from 9 of 15 decreasing to 2 of 15 and increased from 4 of 10 to 7 of 10, respectively. Fifteen of 24 patients had undergone a prior operation, 9 of 24 patients had not. The results for patients with no previous operation were better than results for patients who had undergone an operation before SCR, see Table II.

Table II.

Results for 24 patients after completed follow-up.

Average scores	Graft integrity, 21 patients	No graft integrity, 3 patients	No prior operation, 9 patients	Prior operation, 15 patients	No infraspinatus tendon defect, 9 patients	Infraspinatus tendon defect, 15 patients	Total, 24 patients
Constant Score increase during FU	26-57	24-48	23-62	27-50	26-42	25-56	25-57
Constant pain score decrease during FU	9/15-2/15	10/15-5/15	10/15-0/15	9/15-3/15	11/15-3/15	8/15-2/15	9/15-2/15
Constant elevation score increase during FU	4/10-7/10	4/10-7/10	3/10-7/10	5/10-7/10	6/10-8/10	4/10-7/10	4/10-7/10
WORC Index increase during FU	30%-61%	29%-47%	25%-65%	30%-56%	38%-67%	29%-60%	30%-59%

WORC, Western Ontario Rotator Cuff; FU, Follow-up.

Complications

In the group of 24 patients, shoulder improvement was gradual and some patients conveyed that they felt this slow improvement was mentally and emotionally taxing. Meanwhile, they were encouraged by a fairly expedient relief of pain while improvements in function were gradual and slow. In 2 patients, both with a one-tendon defect, the graft failed due to heavy lifting between 2 and 6 months after SCR. In the first case the graft failed on the glenoid side and in the second case on the humeral side. However, after an initial setback in pain and elevation, these 2 patients went on to improve obtaining good results functionally and in pain reduction.

Including the patient with an infected graft, 6 of 28 patients experienced clinical failure (18%), 5 of 27 because of lack of pain relief and functional improvement, and 2 of these in the group of 24 patients. Due to an unsatisfactory result one patient had an RSA following the 2-year follow-up. During the operation an intact graft and no significant arthopathy was found. The other patient developed significant arthropathy and was not satisfied. On an MRI scan, we found a large subtotal graft rupture on the humeral side but the patient declined further surgery. Comparing the preoperative scores to the scores at 2 years follow-up for the 22 of 24 patients that completed the follow-up period and were satisfied with their outcome, all registered scores exceeded recognized minimal clinically important difference levels.^20,23 This indicates that the procedure precipitated a significant positive clinical difference in all patients except for the above mentioned patients with clinical failures. No vascular or neurological complications were registered. No clinically significant shoulder capsulitis was seen. The relevant data on the 24 patients with a completed follow-up period are summarized in Table II.

Discussion

Overall, 29 shoulders were operated on in 28 patients with no preoperative radiographical joint narrowing or humeral head changes, corresponding to maximally Hamada stage 3 arthropathy. One patient died before the end of the follow-up period, leaving 28 patients. Six patients had a clinical failure, including one with an early deep infection. Five of these patients either had or were offered an RSA. Discounting the infection, 5 of the remaining 27 patients had a graft rupture, 3 of which were clinical failures, 2 of which were not. Twenty-four patients completed the follow-up period and for this group, the effect size for CSs and WORC indices was relatively large when performing a power calculation.

All patients had undergone a 3 month physiotherapy program and the majority had undergone at least one prior shoulder operation (17 of 29). The patients had pain which could be ascribed to continuous anterosuperior instability of the joint with subluxation and impaction of the humeral head against the undersurface of the acromion leading to a substantial lack of elevation with unacceptable dysfunction. They had either a single tendon or massive rotator cuff defect and minimal to no rotator cuff arthropathy. It was not found that our patients realistically would benefit from any minor surgical procedure such as a biceps tenotomy, partial tendon repair, or débridement or from local steroid injections or more analgesics to predictably limit their pain and increase their function. In the literature, an indication for an SCR can be a single tendon supraspinatus tendon defect or a massive superoposterior tendon defect.³⁷ The authors found that the patients should primarily be offered treatment based on their pain and dysfunction and not on the exact extent of the posterosuperior tendon defect. If an SCR procedure had not been an option, these patients would have been offered an RSA or a latissimus dorsi transfer.^{1,5,7,12,14,28}

Improvements in functional scores were generally satisfying if there was no narrowing of the glenohumeral joint line or other radiographical features of progressive joint degeneration corresponding to Hamada stages 4 and 5 and no infection. For these patients, increases in score aggregates are equal to or better than in several published studies describing SCR with an interpositional dermal graft.^{2,10,6,13,17,16,20,21,27,25,31,32,38} The improvements for these patients were generally sustainable over a 2-year follow-up period. Our results indicate that the SCR procedure in selected patients operatively treated by a dedicated surgical team may experience sustainable short-term good results, particularly when the degree of glenohumeral arthropathy is limited.

Other reconstructive salvage procedures are RSA and latissimus dorsi tendon transfer. In RSA for rotator cuff arthropathy, several studies have found comparable improvements in functional scores. However, the infection rates and revision rates are considerable, varying from 5% to 52%.^12,14,15 In latissimus dorsi transfer for rotator cuff arthropathy, several studies have found significant relief of pain. The improvement in function based on a variety of functional scores varies between 25% and 130% after varying follow-up periods. Also, the tendon rupture rate is reported as fairly high, from 10% to 44%.^1,7,15,28,36

SCR is purported to have potential biomechanical benefits by reconstructing a static stabilizing capsular fulcrum optimizing function of the remaining intact cuff tissue acting as a check rein to dynamically stabilize the lever arm of the joint.^4,16,37 In our study, follow-up MRI scans were performed 1 year postoperatively in all included patients to document the integrity and position of the xenograft. The graft was found to be intact in 22 of 27 patients (81%), which is within ranges of graft rupture rates in the literature.³⁴ In the group of 24 patients that completed the follow-up period, only 3 of the postoperative MRI scans displayed an anatomically stabilized glenohumeral joint. In the remaining 21 cases, the humeral head was superiorly displaced in relation to the glenoid joint surface with the xenograft directly interposed between the humeral head and the undersurface of the acromion. Thus, in our material, judged from postoperative MRI scans, the SCR graft radiographically seemed to be an interpositional graft and not a structure that yielded stability to the glenohumeral joint. However, at the end of each operation, we observed in all patients a bounce-back (“anti-trampoline”) effect of the graft. Hence, the graft seemed to stabilize the joint in a passive setting. With the observations described, the authors find that the graft might add to stability in a dynamic setting as well as functioning as an interpositional graft.

The xenograft used in this study is about 3 mm thick. Other authors have proposed that a graft thickness of 6 mm or greater should be used.³ If it is thought that the graft only functions as a cushion, an increased graft thickness might yield better results than from studies with thinner grafts, absorbing more pressure and possibly yielding more stability. However, if the graft also functions as a dynamic joint stabilizer as seen in previous laboratory studies^21,33 increased graft thickness might not yield superior results per se. The use of a thicker graft could carry the risk of increased graft tearing and subacromial erosion rates.

The graft seems primarily to function as an interpositional graft, yet secondarily the graft could possibly also function as a stabilizer in a dynamic setting. Our patients achieved a considerable gain in AROM and we, therefore, find it difficult to conclude that the only function of the graft is that of an interpositional graft only yielding pain relief. When evaluating the patients at the various times of follow-up, the authors had no reason to believe other than that the graft improved the dynamic function of the shoulders.

Our contention was that a successful SCR procedure would lead to a correction of anatomical joint features, and thus provides significant improvement in functional scores. The radiographic features did, however, not improve toward centering the humeral head in the glenoid cavity as seen on MRI scans with an intact, functioning rotator cuff. We believe that these radiographic findings could be explained as a chronic dysfunction of the remaining rotator cuff unit in a relaxed shoulder with the patient in the supine position during an MRI scan. Our patients were scanned lying in the supine position. This passive state does not necessarily reflect the true position of the humeral head or the stability of the joint during activities of daily living.

The clinical failure rate was 6 of 28 patients including the infection (21%). In 5 of 27 (19%) patients excluding the infection the graft failed with a complete or almost complete rupture. Nevertheless, 2 of these 5 patients with a graft rupture were satisfied with their functional results. The remaining 3 patients either declined further surgery or had a RSA. Thus, a verified graft rupture did not necessarily have a negative impact correlation on functional scores. Five of 28 procedures were associated with a secondary procedure after the SCR index operation (18%). Four of the 5 graft ruptures were identified within the first 15 of 29 procedures, and the remaining one case developed significant arthropathy later on during the follow-up period. No graft ruptures were found among procedures 16-29. These results might reflect the learning curve of the surgical team. Patients with no prior operation had better results than patients who had been operated on previously.

The shoulder scores and patient scores improved significantly in all patients that completed the follow-up period except for 2. If the presented tendency could be supported by results from a longer term study including a larger population, this could point surgeons toward choosing SCR as a surgical option for patients with the proposed inclusion criteria.

From our MRI scans it cannot be assessed whether there was a biological integration of the xenograft to bone. Perhaps the xenograft will integrate, but to prove this a graft-to-bone biopsy is necessary. Doppler-sonography or an advanced angiographic study might also show vascular activity in the interface between graft and bone indicating biological integration. A second look procedure with a biopsy for such a purpose is not found to be ethically justified on a routine basis.

Based on the scores in this group, patient satisfaction was generally high. Possible reasons for disappointing results in studies with high rates of graft rupture and/or low rates of graft healing could be a relatively small number of procedures performed per surgeon, a higher number of massive rotator cuff defects or too aggressive rehabilitation.^10,12,13,34 Inferior results could be due to inclusion of a large proportion of patients with massive rotator cuff defects, where the posterior cuff tissue could not be repaired or was of a functionally inferior quality. In our study, all 29 patients had their procedures performed by the same primary surgeon and in a majority of the massive cuff defects; the infraspinatus tear was fully repaired (12 of 19). The infection rate was 1 of 29 procedures (3.4%). The rate of infection in pooled series in the literature is 0%-5%.³⁴

SCR is relatively costly utilizing many anchors besides the graft implant. The porcine graft probably does not have any superior mechanical or histological properties compared to human allografts or autografts. The xenograft is cheaper than a human dermal allograft and by choosing to use it, donor site-related morbidity from human autografts with harvest site pain and other changes is avoided.³⁴ The expense for the hardware equipment used during an SCR procedure is cheaper than for an RSA operation. SCR is a technically demanding procedure. Particularly in osteopenic bone, surgeons need experience for intraoperative technical challenges in order to achieve a stable fixation of the dermal graft. Surgical technique, patient compliance and understanding, medical morbidity, and the quality of rehabilitation are all crucial factors for a successful result.

There are several limitations to this study. First, the sample size is fairly limited, yet it is comparable to other studies in size and follow-up period, especially with the described technique using a xenograft. We are continuing to follow these patients and will soon be able to gather results at a 5-year follow-up point. Those patients who reached the 2-year point of follow-up showed maintenance of clinical improvement at that point except for two. We had clear inclusion criteria and included all patients who had a postoperative MRI scan, thus minimizing bias as well as visualizing the structural state of the operated shoulder joint approximately after one year. Second, it could be criticized that we included patients both with a prior operation and no prior operation and, third, that we included patients with a one-tendon defect as well as patients with a two-tendon defect. However, the inclusions reflect the composition of the patient group opting for surgery in our practice and we have separated the results of the 4 subgroups so that differences are clearly presented. Fourth and likewise, there might be a difference in results for patients who had a traumatic tendon defect compared to a nontraumatic defect. Fifth, early onset of correct postoperative rehabilitation is important to obtain a good outcome.^20,35 In our study the rehabilitation was supervised by local primary care physiotherapists. The included patients qualitatively reported a high level of compliance, but the quality of the rehabilitation was unknown, and therefore questionable that it can introduce bias to the results.

Conclusions

Our study presents short-term follow-up and it is, therefore, not possible to draw any certain conclusions or recommendations concerning the long-term treatment effect after this procedure. However, this study suggests that SCR can be a viable solution to obtain pain relief and functional improvement for patients with large irreparable rotator cuff defects with limited or no arthropathy. The group of patients had limited or no pain and a fair range of motion when infection or significant glenohumeral joint arthropathy did not occur. Patients with no development of further glenohumeral arthropathy had satisfactory results and no secondary procedures. The results in our study suggest that SCR can yield considerable functional score gains that can be comparable to results following a RSA or a latissimus dorsi tendon transfer and with a low rate of infection. Also, should the SCR fail, there is still the possibility of offering those patients an established salvage procedure. In most cases, SCR can be performed arthroscopically in a minimally invasive fashion which has potential benefits for postoperative rehabilitation.

Disclaimers

Funding: No funding was disclosed by the authors.

Conflicts of interest: The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.