Superior Migration Of Humeral Head Research Articles

Association Between Rotator Cuff Tears and Superior Migration of the Humeral Head: An MRI-Based Anatomic Study.

Background:Superior humeral migration has been established as a component of rotator cuff disease, as it disrupts normal glenohumeral kinematics. Decreased acromiohumeral interval (AHI) as measured on radiographs has been used to indicate rotator cuff tendinopathy. Currently, the data are mixed regarding the specific rotator cuff pathology that contributes the most to humeral head migration.Purpose:To determine the relationship between severity of rotator cuff tears (RCTs) and AHI via a large sample of magnetic resonance imaging (MRI) shoulder examinations.Study Design:Cohort study; Level of evidence, 3.Methods:A search was performed for 3-T shoulder MRI performed in adults for any indication between January 2010 and June 2019 at a single institution. Three orthopaedic surgeons and 1 musculoskeletal radiologist measured AHI on 2 separate occasions for patients who met the inclusion criteria. Rotator cuff pathologies were recorded from imaging reports made by fellowship-trained musculoskeletal radiologists.Results:A total of 257 patients (mean age, 52 years) met the inclusion criteria. Of these, 199 (77%) had at least 1 RCT, involving the supraspinatus in 174 (67.7%), infraspinatus in 119 (46.3%), subscapularis in 80 (31.1%), and teres minor in 3 (0.1%). Full-thickness tears of the supraspinatus, infraspinatus, or subscapularis tendon were associated with significantly decreased AHI (7.1, 5.3, and 6.8 mm, respectively) compared with other tear severities (P < .001). Having a larger number of RCTs was also associated with decreased AHI (ρ = –0.157; P = .012). Isolated infraspinatus tears had the lowest AHI (7.7 mm), which was significantly lower than isolated supraspinatus tears (8.9 mm; P = .047).Conclusion:Although various types of RCTs have been associated with superior humeral head migration, this study demonstrated a significant correlation between a complete RCT and superior humeral migration. Tears of the infraspinatus tendon seemed to have the greatest effect on maintaining the native position of the humeral head. Further studies are needed to determine whether early repair of these tears can slow the progression of rotator cuff disease.

Arthroscopic superior capsular reconstruction of the shoulder: a narrative review.

Irreparable rotator cuff tears (IRCTs) in young and considerably active patients are difficult to treat because it is mostly associated with poor outcome which may lead to a painful and dysfunctional shoulder. Most of the IRCTs are encountered in massive size rotator cuff tears which associated with high failure rate following surgical repair. Thus, the IRCTs was considered challenging for its poor healing rate following repair which may induce the arthritic changes. Since the advent of arthroscopic superior capsular reconstruction (ASCR) of the shoulder in 2013, it has gained its popularity. The procedure has become the most popular option for joint-preserving shoulder surgery for patients with IRCTs. It works by providing a static restraint to the superior humeral head migration to optimize the rotator cuff force couples, hence improving joint kinematics. The acceptance of superior capsular reconstruction has made it rapidly evolving in terms of a wider variety of procedures and broader surgical indications. Despite the enthusiasm and widely acceptance towards the procedure, there are still many queries that exist regarding the best indications, surgical technique particularly graft of choice, the long-term outcome, and the complication and risk of the superior capsular reconstruction (SCR). This narrative review provide the current evidence of SCR in an attempt to provide a state-of-the-art knowledge.

Comparison of Different Fixation Techniques of the Long Head of the Biceps Tendon in Superior Capsule Reconstruction for Irreparable Posterosuperior Rotator Cuff Tears: A Dynamic Biomechanical Evaluation

Background: In the past decade, superior capsular reconstruction has emerged as a potential surgical approach in young patients with irreparable posterosuperior rotator cuff tears (RCT) and absence of severe degenerative changes. Recently, the use of locally available and biological viable autografts, such as the long head of the biceps tendon (LHBT) for SCR has emerged, with promising early results. Purpose/Hypothesis: The purpose of this study was to investigate the effect of using the LHBT for reconstruction of the superior capsule on shoulder kinematics, along with different fixation constructs in a dynamic biomechanical model. The authors hypothesized that each of the 3 proposed fixation techniques would restore native joint kinematics, including glenohumeral superior translation (ghST), maximum abduction angle (MAA), maximum cumulative deltoid force (cDF), and subacromial peak contact pressure (sCP). Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric shoulders (mean age, 53.4 ± 14.2 years) were tested using a dynamic shoulder simulator. Each specimen underwent the following 5 conditions: (1) intact, (2) irreparable posterosuperior rotator cuff tear (psRCT), (3) V-shaped LHBT reconstruction, (4) box-shaped LHBT reconstruction, and (5) single-stranded LHBT reconstruction. MAA, ghST, cDF and sCP were assessed in each tested condition. Results: Each of the 3 LHBT techniques for reconstruction of the superior capsule significantly increased MAA while significantly decreasing ghST and cDF compared with the psRCT (P < .001 and P < .001, respectively). Additionally, the V-shaped and box-shaped techniques significantly decreased sCP (P = .009 and P = .016, respectively) compared with the psRCT. The V-shaped technique further showed a significantly increased MAA (P < .001, respectively) and decreased cDF (P = .042 and P = .039, respectively) when compared with the box-shaped and single-stranded techniques, as well as a significantly decreased ghST (P = .027) when compared with the box-shaped technique. Conclusion: In a dynamic biomechanical cadaveric model, using the LHBT for reconstruction of the superior capsule improved shoulder function by preventing superior humeral migration, decreasing deltoid forces and sCP. As such, the development of rotator cuff tear arthropathy in patients with irreparable psRCTs could potentially be delayed. Clinical Relevance: Using a biologically viable and locally available LHBT autograft is a cost-effective, potentially time-saving, and technically feasible alternative for reconstruction of the superior capsule, which may result in favorable outcomes in irreparable psRCTs. Moreover, each of the 3 techniques restored native shoulder biomechanics, which may help improve shoulder function by preventing superior humeral head migration and the development of rotator cuff tear arthropathy in young patients with irreparable rotator cuff tears.

Biomechanics in an Incomplete Versus Complete Supraspinatus Tear: A Cadaveric Study.

Background:Degenerative and traumatic changes to the rotator cuff can result in massive and irreparable rotator cuff tears (RCTs).Purpose/Hypothesis:The study objective was to conduct a biomechanical comparison between a small, incomplete RCT and a large, complete RCT. We hypothesized that the incomplete supraspinatus (SS) tear would lead to an incremental loss of abduction force and preserve vertical position of the humeral head, while a complete SS tear would cause superior humeral migration, decrease functional deltoid abduction force, and increase passive range of motion (ROM).Study Design:Controlled laboratory study.Methods:Six cadaveric shoulders were evaluated using a custom testing apparatus. Each shoulder was subjected to 3 conditions: (1) intact/control, (2) 50%, full-thickness, incomplete SS tear, and (3) 100%, complete SS tear. Deltoid abduction force, superior humeral head migration, and passive ROM were measured in static conditions at 0°, 30°, and 60° of glenohumeral abduction, respectively.Results:The intact SS resulted in a mean deltoid abduction force of 2.5, 3.3, and 3.8 N at 0°, 30°, and 60° of abduction, respectively. Compared with the intact shoulder, there was no significant difference in mean abduction force seen in the incomplete tear, while the force was significantly decreased by 52% at 30° of abduction in the complete tear (P = .009). Compared with the incomplete tear, there were significant decreases in abduction force seen in the complete tear, by 33% and 48% (0.9 N and 1.1 N) at 0° and 30° of abduction, respectively (P = .04 and .004). The intact configuration experienced a mean superior humeral head migration of 1.5, 1.4, and 1.1 mm at 0°, 30°, and 60° of abduction, respectively. The complete tear resulted in a superior migration of 3.0 and 4.4 mm greater than the intact configuration at 0° and 30° of abduction, respectively (P = .001). There was a 5° and 10° increase in abduction ROM with 50% and 100% tears, respectively (P = .003 and .03).Conclusion:An incomplete SS tear does not significantly alter the biomechanics of the shoulder, while a large, complete SS tear leads to a significant superior humeral migration, a decreased deltoid abduction force, and a mild increase in passive ROM.Clinical Relevance:Our findings demonstrate the effects of large SS tears on key biomechanical parameters, as they progress from partial tears.

The biomechanics of the supraspinatus-deficient shoulder treated with superior capsular reconstruction vs. reverse total shoulder arthroplasty-experimental study.

Our objective was to compare biomechanical effects of superior capsular reconstruction (SCR) and reverse total shoulder arthroplasty (rTSA) on shoulder motion, in the setting of an irreparable supraspinatus (SS) tear. We hypothesized that rTSA would produce greater improvement in abduction force and shift the humerus inferiorly, while SCR would produce greater range of motion (ROM) and prevent superior migration of the humerus during abduction. Six cadaveric shoulders were evaluated using a custom biomechanical apparatus. Each shoulder underwent four experimental conditions: (1) intact/control, (2) irreparable SS tear, (3) SCR using dermal allograft, and (4) rTSA without SCR. Deltoid abduction force, superior humeral head translation, and passive range of motion were measured in static tendon loading condition at 0, 30, and 60° of glenohumeral abduction. Both rTSA and SCR restored abduction force to intact levels at all abduction angles. rTSA significantly increased abduction force compared with the SS-deficient shoulder at 0, 30, 60° (p = 0.04), while SCR produced a significant increase at 0° (p = 0.05) abduction. rTSA inferiorly shifted the humeral head by 27 mm (p = 0.002). SCR restored superior humeral head translation to intact SS levels. Compared with SCR, rTSA resulted in 25° less passive abduction (p = 0.001) without significant differences in forward flexion/extension. Compared with SCR, rTSA achieved 10° less passive internal rotation at 0° abduction (p = 0.03) and 26° and 17° greater external rotation at 30° and 60° abduction, respectively (p = 0.03, p = 0.04). Our investigation found that abduction force was restored to intact cuff levels by both procedures, without significant differences between the two techniques. SCR restored superior humeral head migration and rTSA translated the humerus inferiorly. rTSA resulted in decreased passive abduction ROM and increased external rotation, compared with SCR. Both SCR and rTSA restore key biomechanical parameters following an irreparable SS tear, although SCR offers superior passive abduction ROM.

Biomechanical effects of superior capsular reconstruction in a rotator cuff–deficient shoulder: a cadaveric study

Superior capsular reconstruction (SCR) has been gaining popularity as a treatment for irreparable rotator cuff tears (RCTs), especially in younger patients. This biomechanical study aimed to investigate how SCR affects functional abduction force, humeral head migration, and passive range of motion following an irreparable RCT. We hypothesized that SCR will restore these parameters to nearly intact shoulder levels. Six fresh-frozen cadaveric shoulders were evaluated using a custom biomechanical testing apparatus. Each shoulder was taken through 3 conditions: (1) intact (control); (2) irreparable, complete supraspinatus (SS) tear; and (3) SCR. Functional abduction force, superior humeral head migration, and passive range of motion, including axial shoulder rotation, were measured in static condition at 0°, 30°, and 60° of glenohumeral abduction. Data were analyzed using the paired Student t testor Wilcoxon signed rank test, depending on the results of normality testing. The irreparable SS tear resulted in significantly lower functional abduction force at 30° of abduction (P = .01) and a trend toward a decrease (P = .17) at 60° compared with the intact configuration. SCR shoulders produced greater functional force at 0° compared with the tear configuration (P = .046). Humeral head migration was significantly increased by 4.4 and 3.0 mm at 0° and 30° of abduction, respectively, when comparing the intact vs. SS tear configurations (P = .001). SCR decreased superior migration down to levels of intact shoulders at 0° and 30° of abduction (P = .008 and P = .013, respectively) and was not significantly different from the intact configuration at any angle. SCR decreased passive shoulder extension compared with the tear configuration and increased abduction compared with the intact configuration (P = .007 and P = .03, respectively). The overall arc of axial rotation was not significantly different between SCR and the intact configuration at any angle. In the setting of an irreparable SS tear, SCR restores key biomechanical parameters of the shoulder to intact levels. SCR should be considered for qualifying patients with irreparable RCTs.

Bone density in massive rotator cuff tears and possible implications in superior capsular reconstruction

Superior capsular reconstruction (SCR) by using either the fascia lata autograft or a dermal allograft patch are newly described solutions that could prevent superior humeral head migration and restore the anteroposterior shoulder muscle force couple. However, despite initially promising clinical and radiographic outcomes, the more recent literature shows disparity in the results. Possible predisposing factors for SCR structural failure is poor bone quality in the humeral and glenoid fixation points. The purpose of this study was to assess bone density at these points using computed tomography. We retrospectively assessed the CT-scans of 26 patients with chronic massive rotator cuff tears (MRCTs). We used the CT-scans of 10 patients without rotator cuff pathology, arthritis or fractures as a control group. Using Horos software, we performed 3D-multiplanar reconstruction of the images and we established the possible anchor placements on the glenoid and humerus. Therefore, we recognized two fixation points on the glenoid (anterior and posterior), approximately 5 mm medial to the articular surface. Respectively we established four fixation points on the humerus, two medially at the limit of the articular surface (anteriorly in the bicipital groove and posteriorly at the level of the infraspinatus) and two laterally (at the same level with medial points in the coronal plane and 1 cm lateraly in the axial plane). The Hounsfield units (HU) were measured at these points. Healthy control patients at the selected glenoid fixation points one density in HU of 235 ± 53 anteriorly and 287 ± 98 posteriorly. The respective values in patients with MRCTs were 125 ± 36 and142 ± 42, and the differences were statistically significant (p > 0.001 and p = 0.001). Medial humeral fixation points in HU were 115 ± 33 anteriorly and 178 ± 58 posteriorly in healthy patients. The respective values in MRCTs were 78 ± 40 and 77 ± 38 (p = 0.034 and p > 0.001). Finally, for the lateral humeral fixation points in the control group, the HU were 111 ± 22 anteriorly and 130 ± 45 posteriorly. In patients with MRCTs the respective values were 68 ± 40 and 69 ± 41 (p = 0.006 and p = 0.002). Assessment with computer tomography shows that bone density is severely affected in patients with MRCTs, compared to healthy controls. Additionally, the glenoid and the posterior humerus seem to be the weakest fixation points for SCR with 50 % less bone density.

Long Head Biceps Tendon as Superior Capsular Reconstruction (LHBT-SCR) augmentation for Massive rotator cuff repair: “The Chinese Way

Massive or irreparable rotator cuff tears remain a challenging with a high failure rates of the tendon re-tear after surgical treatment in sports medicine practice. Superior capsular reconstruction with either fascia lata autograft or a dermal allograft patch has been described to prevent superior humeral head migration and restore the shoulder muscle force couples to achieve the promising results. A modified and simplified surgical procedure using long head biceps tendon (LHBT) autograft as superior capsular reconstruction (LHBT-SCR) to facilitate the massive rotator cuff repair has been descripted as ”Chinese Way” by a team of French surgeons and Chinese surgeons. The surgical technic has been used in China more than 300 cases. The procedure of this LHBT-SCR has been approved with the advantage of least technical demands, simplifies the original demanding, short the surgical time, satisfy the results and patient acceptance. A multi-center prospective studies with large cohort populations and long-term follow-up has been established in China for its effectiveness. The present will introduce the technic in detail.

Biomechanical analysis of latissimus dorsi tendon transfer with and without superior capsule reconstruction using dermal allograft

Irreparable rotator cuff tears (ICTs) remain a challenging treatment dilemma. Superior capsule reconstruction (SCR) acts as a static stabilizer to decrease superior humeral head migration. Latissimus dorsi tendon transfers (LDTs) dynamically decrease superior humeral head migration and improve external rotation. We hypothesized that the dynamic stabilizing effect of the latissimus transfer plus the static stabilizing effect of SCR would improve shoulder kinematics in shoulders with ICTs. Eight fresh-frozen cadaveric shoulders were tested in 5 conditions: (1) intact, (2) ICT (supraspinatus plus anterior half of infraspinatus), (3) SCR with dermal allograft, (4) SCR plus LDT, and (5) LDT alone. Rotational range of motion, superior translation, anteroposterior translation, and peak subacromial contact pressure were measured at 0°, 30°, and 60° of glenohumeral abduction in the scapular plane. Statistical analysis was performed using a repeated-measures analysis of variance test, followed by a Tukey post hoc test for pair-wise comparisons. ICTs increased total shoulder rotation, superior translation, posterior translation, and peak subacromial contact pressure. SCR plus LDT significantly decreased internal rotation only at 60° of abduction. The effect of SCR plus LDT was most evident at lower levels of abduction. At the mid range of abduction (30°), the static stabilizing effect diminishedbut the dynamic stabilizing effect remained, allowing SCR plus LDT to reduce superior translation more effectively than SCR with dermal allograft alone. Adding SCR to LDT adds static stabilization to a dynamic stabilizer. Therefore, SCR plus LDT may provide additional stability at the low to mid ranges of abduction.

Correlation analysis between rotator cuff tear and the superior migration of humeral head

To evaluate the association between rotator cuff tear and the proximal migration of humeral head. In this research, we retrospectively selected 30 patients with unilateral rotator cuff tear in Peking University People's Hospital from September 2015 to May 2016, who received magnetic resonance imaging (MRI) and X-ray of the painful shoulder before enrollment in this study, the duration between the two examinations was no longer than 1 week, and also there was no past history of surgery in the selected shoulders. There was no other exclusion criteria. Upward migration index (UMI) was the ratio between the distance of humeral head center to the lower surface of acromion, and the radius of humeral head circle, which could help to minimize the effect of anatomy difference and imaging magnification, compared with the traditional acromiohumeral distance (AHD). Then we introduced this index to stratify the selected 30 patients into 3 groups, and each group contained 10 patients, UMI of group 1 was >1 and ≤1.2, UMI of group 2 was >1.2 and ≤1.4, UMI of group 3 was >1.4. As the supraspinatus was most commonly affected by pathological change among the four rotator cuff tendons, we took it as the research object. Then we used the Spearman correlation analysis to evaluate the relationship between UMI and fatty degeneration, rotator cuff tear size and the thickness of ruptured supraspinatus tendon from X-ray and MRI. In the A-P view, the average UMI was 1.33 (1.02-1.51, SD: ±0.22). UMI and the tear size had a significant negative correlation (R=-0.584, P<0.01), and also there was a negative correlation between the fatty degeneration of the supraspinatus (R=-0.312, P=0.033). However, there was no correlation between UMI and the thickness of ruptured supraspinatus (R=0.127, P=0.071). UMI is related with the fatty degeneration of supraspinatus and the tear size. The reduction of UMI is a predictable and reliable mark of rotator cuff tear and degeneration in clinic. Physicians can use physical examination and X-ray first when facing the patients with shoulder pain, which is convenient and helpful for evaluating rotator cuff tears.

Pre-operative factors correlated with arthroscopic reparability of large-to-massive rotator cuff tears

BackgroundThe purpose of this study is to determine the pre-operative factors that are associated with reparability of the large-sized and massive rotator cuff tears.MethodsSixty-six patients were included in this prognostic study. Demographic data, radiographic and MRI parameters were collected. Arthroscopic rotator cuff repair was performed for all included patient. Complete rotator cuff repair was achieved when the tendon covered up at least 50% of the anatomical footprint. The receiver operating characteristic (ROC) curve was analysed to define the cut-off level of each significant factor.ResultsEleven large-sized rotator cuff tears and fifty-five massive rotator cuff tears were defined from MRI. Fifty-four patients were in the complete repair group, and twelve patients were in the partial repair group. The mean duration between MRI and surgery of 5.5 weeks. Reparability was correlated with age, mediolateral (ML) and anteroposterior (AP) tear size, rotator cuff arthropathy, superior migration of humeral head, fatty infiltration and atrophy of the supraspinatus muscle, and fatty infiltration of infraspinatus muscle (p < 0.05). The ROC curve defined a cut-off level of each predicting factor which included age of ≥65 years, mediolateral tear size of ≥36 mm, anteroposterior tear size of ≥22 mm, Hamada’s rotator cuff arthropathy of ≥class2, acromiohumeral interval of ≥6 mm, ≥stage3 supraspinatus fatty infiltration, the presence of supraspinatus muscle atrophy, and ≥ stage1 infraspinatus fatty infiltration. In multivariated regression analysis, age, acromiohumeral interval, and anteroposterior tear size were statistically associated with the reparability. The intra- and inter-observer reliabilities were moderate to excellent.ConclusionAge, ML tear size, AP tear size, rotator cuff arthropathy, superior migration of humeral head, fatty infiltration of supraspinatus and infraspinatus muscles and supraspinatus muscle atrophy all correlate with reparability of large to massive rotator cuff tear.

The Subacromial Balloon Spacer Versus Superior Capsular Reconstruction in the Treatment of Irreparable Rotator Cuff Tears: A Biomechanical Assessment

To compare the subacromial balloon spacer with superior capsular reconstruction (SCR) for the treatment of massive irreparable rotator cuff tears. Eight male cadaveric shoulders were mounted on a custom shoulder simulator that permitted quasistatic deltoid and rotator cuff muscle loading. Four shoulder conditions were tested: intact, irreparable rotator cuff tear (torn), subacromial balloon spacer, and SCR. The primary outcomes were superior humeral head migration and functional shoulder abduction force, which were measured at 0°, 30°, 60°, and 90° of shoulder abduction. In comparison to the intact condition, the torn condition resulted in a significant increase in superior humeral head migration at 0° (P= .03) and 30° (P= .02) of abduction. Insertion of the subacromial balloon spacer restored the humeral head position such that it was not significantly different from the intact condition (P= .18). Similarly, SCR restored the humeral head position such that it was not significantly different from the intact condition (P= .99). No significant differences were found between the balloon and SCR (P= .99). The functional abduction force was significantly decreased after tear creation (P= .01); however, the subacromial balloon (P= .40) and SCR (P= .99) restored functional abduction force comparable to the intact shoulder state. On the basis of the results, both techniques function to decrease superior humeral head migration and to restore more normal glenohumeral joint position and forces during various abduction positions. No substantial differences were identified between techniques at timezero. The results of this laboratory study indicate that the balloon and SCR both provided mechanical effects that restored the humeral head position from the superiorly migrated location. As such, similar clinical effects can be expected at time zero in patients with massive rotator cuff tears.

Relationship Between Deltoid and Rotator Cuff Muscles During Dynamic Shoulder Abduction: A Biomechanical Study of Rotator Cuff Tear Progression

Background: Previous biomechanical studies regarding deltoid function during glenohumeral abduction have primarily used static testing protocols. Hypotheses: (1) Deltoid forces required for scapular plane abduction increase as simulated rotator cuff tears become larger, and (2) maximal abduction decreases despite increased deltoid forces. Study Design: Controlled laboratory study. Methods: Twelve fresh-frozen cadaveric shoulders with a mean age of 67 years (range, 64-74 years) were used. The supraspinatus and anterior, middle, and posterior deltoid tendons were attached to individual shoulder simulator actuators. Deltoid forces and maximum abduction were recorded for the following tear patterns: intact, isolated subscapularis (SSC), isolated supraspinatus (SSP), anterosuperior (SSP + SSC), posterosuperior (infraspinatus [ISP] + SSP), and massive (SSC + SSP + ISP). Optical triads tracked 3-dimensional motion during dynamic testing. Fluoroscopy and computed tomography were used to measure critical shoulder angle, acromial index, and superior humeral head migration with massive tears. Mean values for maximum glenohumeral abduction and deltoid forces were determined. Linear mixed-effects regression examined changes in motion and forces over time. Pearson product-moment correlation coefficients (r) among deltoid forces, critical shoulder angles, and acromial indices were calculated. Results: Shoulders with an intact cuff required 193.8 N (95% CI, 125.5 to 262.1) total deltoid force to achieve 79.8° (95% CI, 66.4° to 93.2°) of maximum glenohumeral abduction. Compared with native shoulders, abduction decreased after simulated SSP (–27.2%; 95% CI, –43.3% to –11.1%, P = .04), anterosuperior (–51.5%; 95% CI, –70.2% to –32.8%, P < .01), and massive (–48.4%; 95% CI, –65.2% to –31.5%, P < .01) cuff tears. Increased total deltoid forces were required for simulated anterosuperior (+108.1%; 95% CI, 68.7% to 147.5%, P < .01) and massive (+57.2%; 95% CI, 19.6% to 94.7%, P = .05) cuff tears. Anterior deltoid forces were significantly greater in anterosuperior (P < .01) and massive (P = .03) tears. Middle deltoid forces were greater with anterosuperior tears (P = .03). Posterior deltoid forces were greater with anterosuperior (P = .02) and posterosuperior (P = .04) tears. Anterior deltoid force was negatively correlated (r = −0.89, P = .01) with critical shoulder angle (34.3°; 95% CI, 32.0° to 36.6°). Deltoid forces had no statistical correlation with acromial index (0.55; 95% CI, 0.48 to 0.61). Superior migration was 8.3 mm (95% CI, 5.5 to 11.1 mm) during testing of massive rotator cuff tears. Conclusion: Shoulders with rotator cuff tears require considerable compensatory deltoid function to prevent abduction motion loss. Anterosuperior tears resulted in the largest motion loss despite the greatest increase in deltoid force. Clinical Relevance: Rotator cuff tears place more strain on the deltoid to prevent abduction motion loss. Fatigue or injury to the deltoid may result in a precipitous decline in abduction, regardless of tear size.

Long Head of the Biceps as a Suitable Available Local Tissue Autograft for Superior Capsular Reconstruction: “The Chinese Way”

Massive irreparable rotator cuff tears remain a challenging condition during daily clinical practice. Irreversible fatty infiltration of muscles and excessive chronic retraction of tendons predispose to high failure rates of their surgical treatment. Superior capsular reconstruction with either fascia lata autograft or a dermal allograft patch is a newly described solution that could prevent superior humeral head migration and restore the anteroposterior shoulder muscle force couples. The purpose of this article is to propose a technical modification of superior capsular reconstruction using long head of the biceps tendon autograft. The tendon's insertion into the glenoid is left intact, whereas laterally, it is tenotomized, transferred, and sutured with anchors onto the footprint of the supraspinatus tendon acting as a superior static stabilizer of the shoulder joint. Although this surgical modification has theoretical biological advantages, could be performed with the least technical demands, and simplifies the original demanding procedure, further prospective studies with large cohort populations and long-term follow-up are necessary to establish its effectiveness.

Biceps Tendon Tenodesis without Tenotomy: A Method of Augmenting Partial Repairs of Massive Rotator Cuff Tears

To determine if biceps tendon tenodesis without tenotomy , when used in addition to partial repairs of massive rotator cuff tears, allowed for improved patient satisfaction outcomes without significant loss of motion. 15 patients with massive cuff tears(>5 sq. cm.) underwent repair in addition to tenodesis of the long head biceps tendon. The long head origin was not cut and therefore left intact. The follow up period was a minimum of 12 months with a maximum of 24 months. Preoperative and follow up results were measured by Oxford Pain Scores, American Shoulder and Elbow Surgeons Score (ASES), and Constant Shoulder Score. Range of motion loss was measured as a percentage of the combined range of motion of the opposite shoulder. The averaged Constant Score improved from 17.8 to 75.3. ASES improved from 16.3 to 77.4. Oxford Pain Score improved from 14 to 33. The average combined loss of motion was 9 degrees. No patient had pain in the biceps tendon groove at final evaluation. Tenodesis without tenotomy of the biceps tendon long head when used in addition to partial repair of massive rotator cuff tears, may help to improve patiient satisfaction scores. The tenodesed long head may act as a restraint to superior humeral head migration, thereby reducing some of the stresses on the competed partial rotator cuff repair. This construct however, could result in a tethering of the shoulder and thereby result in significant loss of motion. The average combined loss of only 9 degrees had minimal clinical significance.

Rotator cuff tears after total shoulder arthroplasty in primary osteoarthritis: A systematic review.

Rotator cuff tears have been reported to be uncommon following total shoulder arthroplasty (TSA). Postoperative rotator cuff tears can lead to pain, proximal humeral migration, and glenoid component loosening. The purpose of this paper was to evaluate the incidence of post-TSA rotator cuff tears or dysfunction in osteoarthritic patients. A systematic review of multiple databases was performed using preferred reporting items for systematic reviews and meta-analyses guidelines. Levels I-IV evidence clinical studies of patients with primary osteoarthritis with a minimum 2-year follow-up were included. Fifteen studies with 1259 patients (1338 shoulders) were selected. Student's t-tests were used with a significant alpha value of 0.05. All patients demonstrated significant improvements in motion and validated clinical outcome scores (P < 0.001). Radiographic humeral head migration was the most commonly reported data point for extrapolation of rotator cuff integrity. After 6.6 ± 3.1 years, 29.9 ± 20.7% of shoulders demonstrated superior humeral head migration and 17.9 ± 14.3% migrated a distance more than 25% of the head. This was associated with an 11.3 ± 7.9% incidence of postoperative superior cuff tears. The incidence of radiographic anterior humeral head migration was 11.9 ± 15.9%, corresponding to a 3.0 ± 13.6% rate of subscapularis tears. We found an overall 1.2 ± 4.5% rate of reoperation for cuff injury. Nearly all studies reported indirect markers of rotator cuff dysfunction, such as radiographic humeral head migration and clinical exam findings. This systematic review suggests that rotator cuff dysfunction following TSA may be more common than previously reported. IV, systematic review of Levels I-IV studies.

Alterations in Glenohumeral Kinematics in Patients With Rotator Cuff Tears Measured With Biplane Fluoroscopy

To quantitatively measure the 3-dimensional (3D) glenohumeral translations during dynamic shoulder abduction in the scapular plane, using a biplane fluoroscopy system, in patients with supraspinatus rotator cuff tears. A custom biplane fluoroscopy system was used to measure the 3D position and orientation of the scapula and humerus of 14 patients with full-thickness supraspinatus or supraspinatus and infraspinatus rotator cuff tears and 10 controls as they performed shoulder abduction over their full range of motion. The 3D geometries of the scapula and humerus were extracted from a computed tomography scan of each shoulder. For each frame, the 3D bone position and orientation were estimated using a contour-based matching algorithm, and the 3D position of the humeral head center was determined relative to the glenoid. For each subject the superior-inferior and anterior-posterior translation curves were determined from 20° through 150° of arm elevation. The humeral head in shoulders with rotator cuff tears was positioned significantly inferior compared with controls for higher elevation angles of 80° to 140° (P < .05). For both groups the humeral head translated inferiorly during shoulder abduction from 80° (P= .044; rotator cuff tear v controls:-0.2 ± 1.3 v 1.2 ± 1.4 mm) up to 140° (P= .047; rotator cuff tear v controls:-1.3 ± 2.2 v 0.44 ± 1.4 mm). There was no significant translation in the anterior- posterior direction. Patients with well-compensated single or 2-tendon rotator cuff tears show no dynamic superior humeral head migration but unexpectedly show an inferior shift during active elevation. It is unclear whether the size of the translational differences found in this study, while statistically significant, are also of clinical significance. Level III, comparative study.

Effectiveness of an intervention program for management of shoulder disorders in industrial workers: A workplace study

Shoulder work-related musculoskeletal disorders represent a major occupational health problem. The most common shoulder disorder described in the literature is the subacromial impingement syndrome. This pathomechanism is generally associated with an abnormal superior humeral head migration during arm elevation. The aim of this study is to investigate the effect of a specific closed-chain humeral head centering exercise on shoulder pain and function at workplace. 20 subjects with impingement symptoms have performed 5 dynamic humeral head centering sessions with the help of a specific device (Scapuleo™, Europhyseo). Shoulder pain and function were evaluated at baseline, after the first exercise session (immediate effects) and after the last exercise session (intervention program effects). Shoulder pain was assessed by means of visual analog scale. Shoulder function was evaluated using analytic active range of motion tests (modified Yocum test; arm abduction) and functional test (repetitive pointing task). After the first training session, shoulder pain significantly decreased ( P < 0.01). One-session effect was also observed on shoulder range of motion during both modified Yocum test ( P < 0.001) and arm abduction ( P < 0.01). Finally, all dependent variables were significantly improved at the end of the intervention program. The results of this study could be explained by humeral head centering improvement and rotator cuff muscles recruitment. Immediate and apparent beneficial effects induced by this intervention program fitted health and performance issues, essential for individuals as for companies. This study underlined the relevance of specific therapeutic exercises in work-related musculoskeletal management at the workplace.

A Comparison of Biceps Labrum Complex Findings in Patients With and Without Superior Migration of the Humeral Head in Large or Massive Rotator Cuff Tears: 比較在患有旋轉袖肌巨大破裂的病人中有和沒有肱骨頭向上遷移對於肱二頭肌盂唇複合體的影響

BackgroundThe purpose of this study was to clarify the relationship between superior migration of the humeral head and findings of biceps labrum complex (BLC) in large or massive rotator cuff tears. MethodsForty-nine shoulders that underwent surgery for torn supraspinatus and infraspinatus tendons were included. Patients were divided into two groups according to the acromio–humeral interval (AHI). Arthroscopic findings of BLC were classified into five types; Type 0; normal shape, Type 1: fraying; Type 2: detachment; Type 3: attrition of BLC and superior glenoid; and Type 4: defect. ResultsThe group without migration (AHI ≥ 7 mm) consisted of 21 shoulders and that with migration (AHI < 7 mm) was 28 shoulders. There were significantly more patients with Types 2, 3, and 4 in the group with migration than without migration. ConclusionThis study indicates a potential relationship between BLC injury and superior humeral head migration accompanied by a rotator cuff tear.

Scapular orientation following repetitive prone rowing: Implications for potential subacromial impingement mechanisms

While fatigue of the rotator cuff demonstrably causes superior humeral head migration and concomitant risk of impingement, the relationship between specific muscular fatigue, scapular dyskinesis and impingement risk is less clear. The purpose of this study was to examine changes in scapular orientation following a simulated prone rowing fatiguing protocol that targeted the scapula stabilizing muscles while attempting to alleviate rotator cuff muscular demands. Scapular orientation and muscle activity were collected from participants before and immediately after the fatiguing task. This task fatigued both the stabilizing (upper and middle trapezius, and latissimus dorsi) and rotator cuff (supraspinatus, and infraspinatus) muscles. The upper extremity muscle fatigue pattern caused by the protocol did not elicit any significantly changes in three-dimensional scapular position with all post-fatigue changes being ⩽1° (p=0.17–0.58). These results indicated that scapular reorientation is likely not the dominant mechanism of fatigue-induced subacromial impingement development. However, the substantial variability present in the kinematics prevents complete exclusion of scapular dyskinesis as a secondary causal mechanism of impingement.