Irreparable Rotator Cuff Tears: A Biomechanical Comparison of Superior Capsuloligamentous Complex Reconstruction Techniques and an Interpositional Graft Technique
Abstract:Background: Irreparable rotator cuff tears lead to superior translation of the humeral head. Numerous surgical management options are available to treat the condition. Purpose: To compare superior capsule stability among different types of patch grafting in irreparable rotator cuff tears. Methods: Six cadaveric shoulders were tested in a custom-designed shoulder testing system. Superior translation of the humerus and subacromial contact pressure were quantified in an intact condition (condition 1), after cutti… Show more
“…Along with the rotator cuff, the superior capsule is seen as an important static stabilizer of the shoulder joint, preventing superior migration of the humeral head. 3,4,9,24,34,46 In massive rotator cuff tears, repair of these structures often remains challenging due to atrophy, retraction, and fatty infiltration of the remaining rotator cuff. 5,22,27 Although arthroplasty and muscle tendon transfers have been described, clinical outcomes have been mixed and significant complications have been reported.…”
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.
“…Along with the rotator cuff, the superior capsule is seen as an important static stabilizer of the shoulder joint, preventing superior migration of the humeral head. 3,4,9,24,34,46 In massive rotator cuff tears, repair of these structures often remains challenging due to atrophy, retraction, and fatty infiltration of the remaining rotator cuff. 5,22,27 Although arthroplasty and muscle tendon transfers have been described, clinical outcomes have been mixed and significant complications have been reported.…”
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.
BackgroundIrreparable 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 methodsThe 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.ResultsAfter 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.ConclusionWith 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.
“…There was also a less superior translation of the humerus with three-point fixation than with two-point fixation. This suggests that to better restore glenohumeral stability, SCR graft fixation to the glenoid with three suture anchors instead of two suture anchors is necessary ( 75 ). Figure 2 Intraoperative arthroscopic view of the superior part of the glenoid.…”
The treatment of rotator cuff tears (RCTs) has evolved. Nonsurgical treatment is adequate for many patients; however, for those for whom surgical treatment is indicated, rotator cuff repair provides reliable pain relief and good functional results. However, massive and irreparable RCTs are a significant challenge for both patients and surgeons.
Superior capsular reconstruction (SCR) has become increasingly popular in recent years. It works by passively restoring the superior restriction of the humeral head, thus restoring the pair of forces and improving the kinematics of the glenohumeral joint. Early clinical results using fascia lata (FL) autograft were promising in terms of pain relief and function.
The procedure has evolved, and some authors have suggested that FL autografts could be replaced by other methods. However, surgical techniques for SCR are highly variable, and patient indications remain undefined. There are concerns that the available scientific evidence does not support the popularity of the procedure.
This review aimed to critically evaluate the biomechanics, indications, procedural considerations, and clinical outcomes associated with the SCR procedure.
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