Irreparable Rotator Cuff Tears: A Biomechanical Comparison of Superior Capsuloligamentous Complex Reconstruction Techniques and an Interpositional Graft Technique

Biomechanical outcomes of superior capsular reconstruction for irreparable rotator cuff tears by different graft materials-a systematic review and meta-analysis

Background

Irreparable rotator cuff tears (IRCT) are defined as defects that cannot be repaired due to tendon retraction, fat infiltration, or muscle atrophy. One surgical remedy for IRCT is superior capsular reconstruction (SCR), which fixes graft materials between the larger tuberosity and the superior glenoid.

Patients and methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria were followed for conducting the systematic review and meta-analysis. From their inception until February 25, 2022, Pubmed, Embase, and Cochrane Library's electronic databases were searched. Studies using cadavers on SCR for IRCT were also included. The humeral head's superior translation and subacromial peak contact pressure were the primary outcomes. The humeral head's anteroposterior translation, the kind of graft material used, its size, and the deltoid load were the secondary outcomes.

Results

After eliminating duplicates from the search results, 1,443 unique articles remained, and 20 papers were finally included in the quantitative research. In 14 investigations, the enhanced superior translation of the humeral head was documented in IRCTs. In 13 studies, a considerable improvement following SCR was found, especially when using fascia lata (FL), which could achieve more translation restraints than human dermal allograft (HDA) and long head of bicep tendon (LHBT). Six investigations reported a subacromial peak contact pressure increase in IRCTs, which could be rectified by SCR, and these studies found a substantial increase in this pressure. The results of the reduction in subacromial peak contact pressure remained consistent regardless of the graft material utilized for SCR. While there was a statistically significant difference in the change of graft material length between FL and HDA, the change in graft material thickness between FL and HDA was not significant. The humeral head's anterior-posterior translation was rising in IRCTs and could be returned to its original state with SCR. In five investigations, IRCTs caused a significant increase in deltoid force. Furthermore, only one study showed that SCR significantly decreased deltoid force.

Conclusion

With IRCT, SCR might significantly decrease the glenohumeral joint's superior and anterior-posterior stability. Despite the risks for donor-site morbidity and the longer recovery time, FL is still the best current option for SCR.

Arthroscopic Biologic Interpositional Tuberosity Graft for the Treatment of Irreparable Rotator Cuff Tears

Massive, irreparable rotator cuff tears in younger, more active patients present a unique treatment challenge to shoulder surgeons. In the past few years, new techniques continue to emerge to address this challenging problem. The superior capsular reconstruction technique has been accepted as an option for addressing this problem. While initial results are encouraging, pitfalls remain regarding technical challenges, healing and protracted rehabilitation due to delayed motion protocols. We present an alternative approach to the massive, irreparable rotator cuff tears using a biologic interpositional humeral -based graft.

Superior Capsular Reconstruction: A Systematic Review of Surgical Techniques and Clinical Outcomes

PURPOSE

To evaluate surgical techniques and clinical outcomes of arthroscopic superior capsular reconstruction (SCR) for the treatment of massive irreparable rotator cuff tears.

METHODS

A systematic review was registered with PROSPERO and performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The PubMed, Scopus, and Cochrane databases were searched. Studies investigating SCR with reported surgical techniques were included. Animal studies, cadaveric studies, review studies, and letters to the editor were excluded. The technical aspects of the surgical techniques for SCR were analyzed in each article, which included graft type, glenoid fixation method, greater tuberosity fixation method, graft passage technique, suture management, margin convergence, concomitant procedures, and postoperative rehabilitation protocol. Clinical outcomes, when available, were also analyzed.

RESULTS

We screened 365 articles, of which 29 described surgical techniques for SCR. According to the Modified Coleman Methodology Score, 24 articles were rated as poor (score < 55), 4 were rated as fair (score between 55 and 69), and 1 was rated as good (score between 70 and 84), with an average score of 25.8 ± 20.9. The most commonly performed technique for SCR used the following: an acellular dermal allograft, 2 biocomposite suture anchors for glenoid fixation, transosseous-equivalent double-row suture anchor fixation for greater tuberosity fixation with 2 biocomposite medial-row anchors and 2 biocomposite lateral-row anchors, the double-pulley technique combined with an arthroscopic grasper and/or pull suture to pass the graft into the shoulder, the performance of both anterior and posterior margin convergence, and a native rotator cuff repair when possible. Only 8 studies reported clinical outcomes, and they showed that SCR provides significant improvement in patient-reported outcomes, significant improvement in shoulder range of motion, variable graft failure rates, low complication rates, and variable reoperation rates. There were no studies comparing outcomes among the various surgical techniques.

CONCLUSIONS

Many surgical techniques exist for arthroscopic SCR. However, no superior technique was shown because there were no studies comparing clinical outcomes among these various techniques.

LEVEL OF EVIDENCE

Level V, systematic review of Level III, IV, and V studies.

Graft Tensioning in Superior Capsular Reconstruction Improves Glenohumeral Joint Kinematics in Massive Irreparable Rotator Cuff Tears: A Biomechanical Study of the Influence of Superior Capsular Reconstruction on Dynamic Shoulder Abduction

Background:

Superior capsular reconstruction (SCR) for massive, irreparable rotator cuff tears has become more widely used recently; however, ideal tensioning of the graft and the influence on joint kinematics remain unknown.

Purpose/Hypothesis:

The purpose of this study was to assess the effects of graft tensioning on glenohumeral joint kinematics after SCR using a dermal allograft. The hypothesis was that a graft fixed under tension would result in increased glenohumeral abduction motion and decreased cumulative deltoid forces compared with a nontensioned graft.

Study Design:

Controlled laboratory study.

Methods:

A total of 10 fresh-frozen cadaveric shoulders were tested using a dynamic shoulder simulator. Each shoulder underwent the following 4 conditions: (1) native, (2) simulated irreparable supraspinatus (SSP) tear, (3) SCR using a nontensioned acellular dermal allograft, and (4) SCR using a graft tensioned with 30 to 35 N. Mean values for maximum glenohumeral abduction and cumulative deltoid forces were recorded. The critical shoulder angle (CSA) was also assessed.

Results:

Native shoulders required a mean (±SE) deltoid force of 193.2 ± 45.1 N to achieve maximum glenohumeral abduction (79.8° ± 5.8°). Compared with native shoulders, abduction decreased after SSP tears by 32% (54.3° ± 13.7°; P = .04), whereas cumulative deltoid forces increased by 23% (252.1 ± 68.3 N; P = .04). The nontensioned SCR showed no significant difference in shoulder abduction (54.1° ± 16.1°) and required deltoid forces (277.8 ± 39.8 N) when compared with the SSP tear state. In contrast, a tensioned graft led to significantly improved shoulder abduction compared with the SSP tear state (P = .04) although abduction and deltoid forces could not be restored to the native state (P = .01). A positive correlation between CSA and maximum abduction was found for the tensioned-graft SCR state (r = 0.685; P = .02).

Conclusion:

SCR using a graft fixed under tension demonstrated a significant increase in maximum shoulder abduction compared with a nontensioned graft; however, abduction remained significantly less than the intact state. The nontensioned SCR showed no significant improvement in glenohumeral kinematics compared with the SSP tear state.

Clinical Relevance:

Because significant improvement in shoulder function after SCR may be expected only when the graft is adequately tensioned, accurate graft measurement and adequate tension of at least 30 N should be considered during the surgical procedure. SCR with a tensioned graft may help maintain sufficient acromiohumeral distance, improve clinical outcomes, and reduce postoperative complications.