Tear pattern after superior capsular reconstruction using an acellular dermal matrix allograft

Effect of Medial or Lateral Graft Failure on Graft Volume and Clinical Outcomes After Superior Capsule Reconstruction for Irreparable Rotator Cuff Tears

BACKGROUND

Graft failure is a common complication after superior capsule reconstruction (SCR). The graft in SCR is fixed on the greater tuberosity and superior glenoid, and graft failure has been reported on both sides.

PURPOSE

To evaluate the clinical manifestations of patients with graft failure after SCR and identify the clinical and radiological differences between medial and lateral graft failure.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent SCR with a dermal allograft for symptomatic irreparable rotator cuff tears between March 2018 and September 2021 were retrospectively reviewed. All patients had minimum 2-year follow-up and underwent magnetic resonance imaging at 6 months postoperatively. Patients with graft failure were divided into 2 groups: those with lateral graft failure on the greater tuberosity side (group I) and those with medial graft failure on the glenoid side (group II). Patients with intact grafts were included in group III as a control group. Intergroup differences in clinical and radiological characteristics were analyzed, and multiple regression analysis was performed.

RESULTS

Among the 93 patients included, there were 18 patients in group I, 15 in group II, and 60 in group III. Overall, 11 patients (61.1%) in group I and 9 patients (60.0%) in group II had a partial graft rupture at one anchor. The postoperative graft volume was significantly lower in group I than in groups II and III (2514.0 ± 564.3 mm3, 3183.5 ± 547.1 mm3, and 3198.0 ± 584.8 mm3, respectively; P = .002 for group I vs II; P < .001 for group I vs III). The acromiohumeral distance (AHD) was significantly increased at 6 months postoperatively compared with before surgery in group I (6.6 ± 1.6 mm vs 4.3 ± 1.9 mm, respectively; P < .001) and group II (7.4 ± 1.3 mm vs 5.7 ± 1.7 mm, respectively; P = .002). However, group I exhibited a significantly greater decrease in the AHD over time than group II (P < .001) and a significantly lower AHD at the final follow-up than the other groups (P < .001). The postoperative American Shoulder and Elbow Surgeons score was significantly lower in group I than in the other groups (P < .001). On multiple regression analysis, fatty infiltration of the infraspinatus muscle, Hamada grade, and graft width were independent factors for lateral graft failure.

CONCLUSION

Patients with lateral graft failure had inferior clinical outcomes and lower postoperative graft volumes than those with medial graft failure after SCR using a dermal allograft. The AHD of patients with lateral graft failure improved postoperatively; however, it deteriorated over time.

Superior Capsular Reconstruction Using an Acellular Dermal Xenograft or Allograft Improves Shoulder Function but Is Associated with a High Graft Failure Rate

Objectives: The purpose of the present study was to evaluate clinical and functional outcomes, graft integrity rate and progression of osteoarthritis after superior capsular reconstruction (SCR) at short-term follow-up. Methods: Consecutive patients that underwent SCR using an acellular dermal xeno- or allograft between May 2018 and June 2020 for the treatment of irreparable posterosuperior rotator cuff tears were included. Shoulder function (American Shoulder and Elbow Surgeons [ASES] score), pain (Visual Analog Scale [VAS] for pain) and active shoulder range of motion (ROM) were evaluated preoperatively and after a minimum of 24 months postoperatively. Isometric strength was measured at follow-up and compared to the contralateral side. Magnetic resonance imaging was performed to evaluate graft integrity and osteoarthritis progression (shoulder osteoarthritis severity [SOAS] score). Results: Twenty-two patients that underwent SCR using a xeno- (n = 9) or allograft (n = 13) were evaluated 33.1 ± 7.2 months postoperatively. Four patients in the xenograft group underwent revision surgery due to pain and range of motion limitations and were excluded from further analysis (revision rate: 18.2%). Shoulder function (ASES score: 41.6 ± 18.8 to 72.9 ± 18.6, p < 0.001), pain levels (VAS for pain: 5.8 ± 2.5 to 1.8 ± 2.0, p < 0.001) and active flexion (p < 0.001) as well as abduction ROM (p < 0.001) improved significantly from pre- to postoperatively. Active external rotation ROM did not improve significantly (p = 0.924). Isometric flexion (p < 0.001), abduction (p < 0.001) and external rotation strength (p = 0.015) were significantly lower in the operated shoulder compared to the non-operated shoulder. Ten shoulders demonstrated a graft tear at the glenoid (n = 8, 44.4%) or humerus (n = 2, 11.1%). Graft lysis was observed in seven shoulders (38.9%). The graft was intact in one shoulder (5.6%), which was an allograft. A significant progression of shoulder osteoarthritis was observed at follow-up (SOAS score: 42.4 ± 10.1 to 54.6 ± 8.4, p < 0.001). Conclusions: At short-term follow-up, SCR using an acellular dermal xeno- or allograft resulted in improved shoulder function and pain with limitations in active external rotation ROM and isometric strength. Graft failure rates were high and osteoarthritis progressed significantly. Level of Evidence: Retrospective cohort study, Level III.

Clinical and radiological outcomes between superior capsule reconstruction using allografts or xenografts: a 2-year retrospective comparison study

BACKGROUND

Treating symptomatic, massive, irreparable rotator cuff tears remains challenging and controversial. Superior capsule reconstruction (SCR) using the tensor fascia lata has shown promising clinical results; however, due to donor site morbidity, interest in SCR using other grafts has increased. Yet, no studies have compared allografts with xenografts. In addition, the clinical results of graft tears remain controversial. This study compared the clinical and radiological outcomes of SCR between those with allografts and xenografts.

METHODS

Sixty-seven patients who had undergone SCR with allografts or xenografts between January 2016 and December 2020 were included in this retrospective study. Furthermore, 62 patients were evaluated 2 years postsurgery, with five patients excluded due to loss to follow-up or conversion to reverse shoulder arthroplasty. The Constant, American Shoulder and Elbow Surgeons, and visual analog scale scores, range of motion, and radiological outcomes were evaluated before the surgery and at 6 and 24 months after surgery.

RESULTS

The graft tear rate was 23.08% in the allograft group and 42.86% in the xenograft group at 6 months after surgery; at 2 years postsurgery, the gap further widened to 32.43% and 64%, respectively, showing a significant difference. The graft in the allograft group was thicker than that in the xenograft group, and there were significant differences on the humeral side and in the midsubstance area. The allograft group showed significantly better visual analog scale, Constant, and American Shoulder and Elbow Surgeons scores than the xenograft group 2 years postsurgery. However, the difference in clinical outcomes between the two groups did not surpass minimal clinically important differences.

CONCLUSION

Although arthroscopic SCR using xenografts had significantly lower clinical outcome than allografts, this difference did not reach minimal clinically important differences. Arthroscopic SCR using xenografts showed higher graft tear rates than allografts. Even with partial tears, better results were obtained if the graft continuity was maintained. Additionally, after surgery, the xenograft showed less thickness than the allograft and resulted in more tears, specifically in the midsubstance area.

Postoperative Graft Volume Reduction Is Associated With Inferior Clinical Outcomes of Superior Capsule Reconstruction Using an Acellular Dermal Matrix Allograft

PURPOSE

To evaluate whether postoperative graft volume reduction is associated with clinical outcomes after superior capsule reconstruction (SCR) and to identify factors related to graft volume change.

METHODS

Between May 2018 and June 2021, patients who underwent SCR with acellular dermal matrix allograft for irreparable rotator cuff tear with a minimum 1-year follow-up and who had intact graft continuity in postoperative 6-month magnetic resonance imaging were retrospectively reviewed. The lateral half to the medial half of the graft volume ratio was defined as lateral half graft volume ratio. The difference between the preoperative and postoperative lateral half graft volume ratio was defined as lateral half graft volume change. Patients were divided into 2 groups: those with preserved graft volume (group I) and those with reduced graft volume (group II). Intergroup differences in clinical and radiological characteristics were analyzed.

RESULTS

A total of 81 patients were included, with 47 (58.0%) in group I and 34 (42.0%) in group II. Group I showed significantly lower lateral half graft volume change (0.018 ± 0.064 vs 0.370 ± 0.177; P < .001) than group II. Group II showed significantly greater preoperative Hamada grade (1.3 ± 0.5 vs 2.2 ± 0.6, P < .001), an anteroposterior distance of the graft at the greater tuberosity (APGT) (30.3 ± 4.8 vs 35.2 ± 3.8, P < .001), and fatty infiltration of infraspinatus (2.3 ± 0.9 vs 3.1 ± 0.8, P < .001) and subscapularis (0.9 ± 0.9 vs 1.6 ± 1.3, P = .009) than group I. Group II had a significantly lower proportion of patients achieving MIC in Constant score than group I (70.2% vs 47.1%, P = .035). The Hamada grade, APGT, and fatty infiltration of infraspinatus and subscapularis were independent factors of graft volume change.

CONCLUSIONS

Although SCR improved pain and shoulder function, postoperative graft volume reduction was related to a lower rate of minimal important change achievement in the Constant score compared with preserved graft volume. The preoperative Hamada grade, APGT, and fatty infiltration of infraspinatus and subscapularis were associated with graft volume reduction.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Editorial Commentary: Superior Capsule Reconstruction: Acellular Allograft at 45° of Glenohumeral Abduction Improves Glenohumeral Stability, but Fascia Lata Autograft Remains Superior

Originally, fascia lata autograft was used for superior capsule reconstruction (SCR) to restore glenohumeral stability in irreparable rotator cuff tears. Consistently excellent clinical outcomes with low graft tear rates have been reported, without repair of tears in the supraspinatus and infraspinatus tendons. On the basis of our experience and studies published in the 15 years since the first SCR using fascia lata autograft in 2007, we can say that this technique is the gold standard. SCR using fascia lata autograft can cover all irreparable rotator cuff tears (Hamada grade 1-3; although the indication for SCR using other grafts, including dermal allograft, biceps, and hamstrings, is only Hamada grade 1 or 2); creates excellent clinical outcomes with low graft tear rates in short-term, long-term, and multicenter studies; regenerates the fibrocartilaginous insertions at both the greater tuberosity and superior glenoid according to histological study; and enables complete restoration of shoulder stability and subacromial contact pressure in cadaveric biomechanical studies. In some countries, dermal allograft is preferred for SCR. However, high rates of graft tear and complications have been reported after SCR using dermal allografts, even in limited indications of irreparable rotator cuff tears (Hamada grade 1 or 2). This high failure rate results from the lack of stiffness and thickness of the dermal allograft. Dermal allografts in SCR can be elongated by 15% after only a couple of physiological shoulder movements, whereas fascia lata graft cannot. This 15% graft elongation, which creates less glenohumeral stability and high graft tear after SCR, is a fatal problem of dermal allograft for SCR in irreparable rotator cuff tears. Current research suggests that SCR using dermal allografts is not strongly recommended for the treatment of irreparable rotator cuff tears. Dermal allograft probably should be used only for augmentation of rotator cuff complete repair.

Factors influencing clinical outcomes in superior capsular reconstruction: A scoping review

Background

It is undetermined how effective superior capsule/capsular reconstruction (SCR) is, and which factors influence clinical outcomes.

Questions/purposes

(1) To identify which factors influence outcomes in SCR, (2) to evaluate the effect of graft integrity on clinical outcomes, and (3) to compare SCR to other procedures for irreparable rotator cuff tears.

Methods

PubMed and EMBASE databases were searched for clinical SCR studies. Data on specific factors that influenced outcomes, that compared outcomes between intact/torn graft groups, or compared SCR to alternative treatments for irreparable tears were extracted by two investigators. Random-effects meta-analysis was performed to compare outcomes between intact vs torn SCR grafts.

Results

394 articles were identified. 100 full-text articles were screened. 13 studies were included for scoping review. Eight studies were meta-analyzed. Better clinical scores were found in younger patients, with intact/repairable subscapularis, without acetabulization/arthritis, who played sports. In patients with irreparable tears without arthritis, SCR produced similar clinical scores at 2 years as shoulder arthroplasty and partial infraspinatus repair, and greater improvements in ASES and Constant scores than latissimus dorsi tendon transfer. Intact grafts produced better VAS (mean difference [MD] = 0.97, 95% confidence interval [-1.45-0.50], P < 0.0001, I 2 = 67%, n [patients] = 261), ASES (MD = 8.29, [2.89-13.70], P = 0.003, I 2 = 74%, n = 281), external rotation (MD = 4.49, [0.36-8.61], P = 0.03, I 2 = 0%, n = 240), and acromiohumeral distance (MD = 2.45, [0.96-3.94], P = 0.001, I 2 = 92%, n = 260) than torn grafts.

Conclusions

Patients who underwent SCR for irreparable rotator cuff tears were more likely to have better clinical outcomes if they were younger, had intact/repairable subscapularis, without acetabulization/arthritis, played sports and had intact grafts.