Stemless Anatomic and Reverse Shoulder Arthroplasty in Patients under 55 years of age with Primary Glenohumeral Osteoarthritis: An analysis of the Australian Orthopaedic Association National Joint Replacement Registry at five years.

BACKGROUND: Primary glenohumeral osteoarthritis in young patients poses challenging treatment decisions. Arthroplasty options have different failure profiles and implant survivorship patterns. This registry study aims to analyze the cumulative per cent revision rate (CPR) of different types of arthroplasties conducted for primary osteoarthritis in patients under 55 years of age. METHODS: This comparative observational national registry study included all shoulder arthroplasty for osteoarthritis in patients under 55 years of age undertaken between January 1st, 2005, and December 31st, 2022. Partial hemi resurfacing and hemi stemless procedures were excluded. The cumulative percentage of revision (CPR) was determined using Kaplan-Meier estimates of survivorship and hazard ratios (HR) from Cox proportional hazard models adjusted for gender. Reasons for revision of each type of arthroplasty and cumulative incidence of revision diagnoses were analyzed. RESULTS: 2111 primary shoulder arthroplasties were compared. Glenoid erosion is the predominant cause of revision for humeral resurfacing (29.8%) and hemiarthroplasty (35.5%). Instability is the predominant cause of revision for stemmed anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA), while loosening is the predominant cause of revision for stemless ATSA. The 6-year CPR is 12.8% for humeral resurfacing (HRA), 14.1% for hemiarthroplasty (HA), 12.4% for stemmed (ATSA), 7.0% for stemless ATSA, and 6.5% for (RTSA). Stemmed ATSA had a higher revision rate than RTSA (entire period HR=2.04 (95% confidence interval (CI) 1.16, 3.57), p=0.012). In contrast, the revision rate of stemless ATSA was not different from RTSA (HR =1.05 (95% CI 0.51, 2.19), p=0.889). Males outnumber females for all shoulder arthroplasty categories. DISCUSSION: RTSA and stemless ATSA are viable options in young patients with primary osteoarthritis. Their short-to medium-term revision rates are comparable to those of older patients and lower than those associated with HRA, HA, and stemmed ATSA. CONCLUSION: In the predominantly male patient population under the age of 55, reverse shoulder arthroplasty and stemless ATSA have a lower short-term revision risk than stemmed ATSA.

Qualitative analysis of the Supraspinatus muscle fatty infiltration on MRI - Correlation of the Tangent sign with Goutallier grade at the Y view and Medial Scapular border in large retracted rotator cuff tears.

BACKGROUND: Surgically repairing rotator cuff tears with a higher extent of fatty infiltration is controversial. Current evidence supports performing rotator cuff repair in patients exhibiting Goutallier stage 3-4 fatty infiltration. However, the presence of retraction complicates accurate assessment using the Goutallier Classification, particularly on the lateral Y-view. A shift towards classifying fatty infiltration in more medial regions may enhance the precision of tissue quality quantification. The objective of this study was to analyze the uniformity of fatty infiltration within the entire supraspinatus muscle using the Goutallier Classification across three scapular Y-view sections and to examine the association between Goutallier grade, tangent sign, and modified Patte stage. METHODS: A retrospective evaluation was conducted on preoperative magnetic resonance imaging (MRI) scans from a consecutive series of 97 patients who had previously undergone arthroscopic rotator cuff repairs. Three supraspinatus sections on the MRI sagittal plane were identified: the lateral Y-view (section one), a medial section at the suprascapular notch anatomical landmark (section two), and a section 3 cm medial from the suprascapular notch Medial Scapular Body (section three). Goutallier grade, tangent sign, and modified Patte stage were used to evaluate fatty infiltration, muscle atrophy, and tendon retraction, respectively. RESULTS: Section one had the highest Goutallier grade, while section three had the lowest. Intra-observer rest retest reliability analysis showed excellent consistency in all sections with section one (ICC=0.920, 95% CI), section two (ICC=0.917, 95% CI), and section three (ICC=0.923, 95% CI) for Goutallier grade. Inter-observer reliability analysis also revealed excellent consistency in sections one (ICC=0.951, 95% CI), section two (ICC=0.949, 95% CI), and section three (ICC=0.922, 95% CI) for Goutallier grade. A strong correlation was observed between Goutallier grade and modified Patte stage (τb=0.43-0.56, p=0.001), and between Goutallier grade and tangent sign (τb=0.43-0.54, p=0.001) across all sections. CONCLUSION: The severity of fatty infiltration within the supraspinatus muscle belly is inconsistent, with the lateral portion being the most severe and the medial portion the least severe. Goutallier grade demonstrates a strong correlation with tangent sign and modified Patte stage. This suggests that tendon retraction results in a potential overestimation in the amount of fatty infiltration defining some tears unjustly irreparable when measuring at the traditionally described lateral Y-view position compared with 3cm medial.

Medial scapular body (MSB) Goutallier classification: MRI-based reliability and validity of evaluation of the Goutallier classification for grading fatty infiltration of the rotator cuff.

BACKGROUND: The degree of atrophy and fatty infiltration of rotator cuff muscle belly is a key predictor for cuff repairability. Traditionally, Goutallier grading of fatty infiltration is assessed at sagittal scapular Y-view. Massive rotator cuff tears are associated with tendon retraction and medial retraction of cuff musculature, resulting in medialization of the muscle bulk. Thus, standard Y-view can misrepresent the region of interest and may misguide clinicians when assessing repairability. It is hypothesized that by assessing the muscle belly with multiple medial sagittal magnetic resonance imaging (MRI) sections at the medial scapular body, the Medial Scapular Body-Goutallier Classification (MSB-GC) will improve reliability and repeatability, giving a more representative approximation to the degree of fatty infiltration, as compared with the original Y-view. METHODS: Fatty infiltration of the rotator cuff muscles were classified based on the Goutallier grade (0-4) at 3 defined sections: section 1, original Y-view; section 2, level of suprascapular notch; and section 3, 3 cm medial to the suprascapular notch on MRI scans. Six subspecialist fellowship-trained shoulder surgeons and 3 musculoskeletal radiologists independently evaluated deidentified MRI scans of included patients. RESULTS: Of 80 scans, 78% (n = 62) were massive cuff tears involving the supraspinatus, infraspinatus, and subscapularis tendons. Interobserver reliability (consistency between observers) for Goutallier grade was excellent for all 3 predefined sections (range: 0.87-0.95). Intraobserver reliability (repeatability) for Goutallier grade was excellent for all 3 sections and 4 rotator cuff muscles (range: 0.83-0.97). There was a moderate to strong positive correlation of Goutallier grades between sections 1 and 3 and between sections 2 and 3 and these were statistically significant (P < .001). There was a reduction in the severity of fatty infiltration on the Goutallier classification from sections 1 to 3 across all muscles: 42.5% of both supraspinatus and infraspinatus were downgraded by 1, 20% of supraspinatus and 3.8% of infraspinatus were downgraded by 2, and 2.5% of supraspinatus were downgraded by 3. CONCLUSION: This study found that applying the Goutallier classification to more medial MRI sections (MSB-GC) resulted in assignment of lower grades for all rotator cuff muscles. Additionally, this method demonstrated excellent test-retest reliability and repeatability. Inclusion of a more medial view or whole scapula on MRI, especially in advanced levels of tear retraction, could be more reliable and representative for assessment of the degree of fatty infiltration within the muscle bulk that could help predict tear repairability and therefore improve clinical decision making, which should be studied further in clinical studies.

All-Arthroscopic Supraspinatus and Infraspinatus Muscle Advancement Leads to High Healing Rate and Excellent Outcomes in Patients With Massive, Retracted Rotator Cuff Tears, Even in Patients With Pseudoparalysis.

PURPOSE: To evaluate the clinical and radiographic outcomes of an all-arthroscopic rotator cuff repair technique involving muscle advancement and double-layer lasso loop (DLLL) repair for massive, retracted posterosuperior cuff tears. METHODS: This was a retrospective case series of patients with massive, retracted posterosuperior cuff tears who underwent the all-arthroscopic muscle advancement technique from March 2017 to September 2021, with a minimum follow-up of 12 months. Key steps included suprascapular nerve release, advancement of the supraspinatus and infraspinatus muscles, and DLLL repair. Preoperative and postoperative visual analog scale score for pain, American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score, University of California, Los Angeles (UCLA) shoulder score, active range of motion, and strength were compared. Preoperative and postoperative structural radiologic characteristics were analyzed. RESULTS: We evaluated 43 shoulders in 38 patients with a mean follow-up period of 18.8 months (range, 12-55 months). Of the 43 shoulders, 4 showed repair failure (9.3% retear rate). Visual analog scale, ASES, Constant, and UCLA scores significantly improved (P < .001) in patients who showed healing on postoperative magnetic resonance imaging (n = 39). ASES, Constant, and UCLA scores were significantly better in the healed group, with 100% exceeding the minimal clinically important difference for the ASES score and UCLA score and 84.2%, for Constant score. A lower proportion of patients in the retear group achieved the minimal clinically important difference. Active range of motion in all planes significantly improved for patients who had healed repairs (P < .001). Relative abduction strength, supraspinatus strength, and infraspinatus strength were at least 90% of those on the contralateral side. The recovery rate of pseudoparalysis (7 patients) was 100%. CONCLUSIONS: All-arthroscopic muscle advancement, coupled with DLLL repair, leads to a high healing rate with excellent clinical outcomes and recovery of strength to at least 90%, even in patients with pseudoparalysis. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The Use of Glenoid Structural Allografts for Glenoid Bone Defects in Reverse Shoulder Arthroplasty.

Background: The use of reverse shoulder arthroplasty as a primary and revision implant is increasing. Advances in implant design and preoperative surgical planning allow the management of complex glenoid defects. As the demand for treating severe bone loss increases, custom allograft composites are needed to match the premorbid anatomy. Baseplate composite structural allografts are used in patients with eccentric and centric defects to restore the glenoid joint line. Preserving bone stock is important in younger patients where a revision surgery is expected. The aim of this article is to present the assessment, planning, and indications of femoral head allografting for bony defects of the glenoid. Methods: The preoperative surgical planning and the surgical technique to execute the plan with a baseplate composite graft are detailed. The preliminary clinical and radiological results of 29 shoulders which have undergone this graft planning and surgical technique are discussed. Clinical outcomes included visual analogue score of pain (VAS), American Shoulder and Elbow Surgeons score (ASES), Constant-Murley score (CS), satisfaction before and after operation, and active range of motion. Radiological outcomes included graft healing and presence of osteolysis or loosening. Results: The use of composite grafts in this series has shown excellent clinical outcomes, with an overall graft complication rate in complex bone loss cases of 8%. Conclusion: Femoral head structural allografting is a valid and viable surgical option for glenoid bone defects in reverse shoulder arthroplasty.

Does forearm referencing using a retroversion guide achieve the targeted retroversion of the humeral component in reverse shoulder arthroplasty?

BACKGROUND: Component positioning affects clinical outcomes of reverse shoulder arthroplasty, which necessitates an implantation technique that is reproducible, consistent, and reliable. This study aims to assess the accuracy and precision of positioning the humeral component in planned retroversion using a forearm referencing guide. METHODS: Computed tomography scans of 54 patients (27 males and 27 females) who underwent primary reverse shoulder arthroplasty for osteoarthritis or cuff tear arthropathy were evaluated. A standardized surgical technique was used to place the humeral stem in 15° of retroversion. Version was assessed intraoperatively visualizing the retroversion guide from above and referencing the forearm axis. Metal subtraction techniques from postoperative computed tomography images allowed for the generation of 3D models of the humerus and for evaluation of the humeral component position. Anatomical humeral plane and implant planes were defined and the retroversion 3D angle between identified planes was recorded for each patient. Accuracy and precision were assessed. A subgroup analysis evaluated differences between male and female patients. RESULTS: The humeral retroversion angle ranged from 0.9° to 22.8°. The majority (81%) of the measurements were less than 15°. Mean retroversion angle (±SD) was 9.9° ± 5.8° (95% CI 8.4°-11.5°) with a mean percent error with respect to 15° of -34% ± 38 (95% CI -23 to -44). In the male subgroup (n = 27, range 3.8°-22.5°), the mean retroversion angle was 11.9° ± 5.4° (95% CI 9.8°-14.1°) with a mean percent error with respect to 15° of -21% ± 36 (95% CI -6 to -35). In the female subgroup (n = 27, range 0.9°-22.8°), mean retroversion angle was 8.0° ± 5.5° (95% CI 5.8°-10.1°) and the mean percent error with respect to 15° was -47% ± 36 (95% CI -32 to -61). The differences between the 2 gender groups were statistically significant (P = .006). CONCLUSION: Referencing the forearm using an extramedullary forearm referencing system to position the humeral stem in a desired retroversion is neither accurate nor precise. There is a nonnegligible tendency to achieve a lower retroversion than planned, and the error is more marked in females.

Restoration of glenoid joint line: a three-dimensional analysis of scapular landmarks.

Background: Restoration of the glenoid joint line in shoulder arthroplasty is important for implant positioning and function. Medialization of the glenohumeral joint line due to glenoid bone loss is commonly encountered in primary and revision of shoulder arthroplasty albeit the direction and location of bone loss varies with different pathology. Three-Dimensional (3D) planning software has assisted in preoperative planning of complex glenoid deformities. However, limited literature is available defining a reliable 3D method to evaluate the glenoid joint line preoperatively. Aims: The purpose of this study is to identify a set of reliable scapular landmarks to be used as reference points to measure the premorbid glenoid joint line using 3D segmented models of healthy scapulae. Methods: Bilateral computed tomography scans from 79 patients eligible for primary stabilization procedures were retrospectively selected from our institutional surgical database (mean age 35 ± 10 years, 58 males and 21 females). 3D models of the contralateral healthy scapulae were created via computed tomography scan segmentation using Mimics 24.0 software (Materialise, Leuven, Belgium). Anatomical landmarks were identified using 3-Matic 16.0 software (Materialise, Leuven, Belgium). The distance between identified landmarks and a sagittal plane created on the deepest point of the glenoid was recorded for each scapula and reliability of each landmark was assessed. Inter- and intra-observer reliabilities were also evaluated using intraclass correlation coefficients (ICCs). Results: Four landmarks showed statistically significant results: the scapular notch (SN), the centroid of the coracoid (CC), a point on the most medial border of the scapula in line with the scapular spine (TS), and the most lateral point of the acromion (AL). The mean (± standard deviation) joint line measured from the SN, CC, TS and AL were 28.36 ± 2.97 mm, 11.66 ± 2.07 mm, 107.52 ± 8.1 mm, and 29.72 ± 4.46 mm, respectively. Inter-observer reliability analysis for SN, TS, and AL showed excellent agreement with ICC values of 0.966, 0.997, and 0.944, respectively, and moderate agreement for CC with ICC of 0.728. Conclusion: The results from this study assist in estimating joint line medialization preoperatively and in planning its subsequent restoration. A set of reliable landmarks can be used as references to estimate the premorbid glenoid joint line preoperatively.

A biomechanical analysis of double-screw, double-button, and screw-button fixation constructs in patient-specific instrument-guided Latarjet procedure.

BACKGROUND: The Latarjet coracoid transfer procedure reliably stabilizes the glenohumeral joint for shoulder instability. However, complications such as graft osteolysis, nonunion and fracture continue to affect patient clinical outcomes. The double-screw (SS) construct is regarded as the gold standard method of fixation. SS constructs are associated with graft osteolysis. More recently, a double-button technique (BB) has been suggested to minimize graft-related complications. However, BB constructs are associated with fibrous nonunion. To mitigate this risk, a single screw combined with a single button (SB) construct has been proposed. It is thought that this technique incorporates the strength of the SS construct and allows micromotion superiorly to mitigate stress shielding-related graft osteolysis. AIMS: The primary aim of this study was to compare the failure load of SS, BB, and SB constructs under a standardized biomechanical loading protocol. The secondary aim was to characterize the displacement of each construct throughout testing. METHODS: Computed tomography scans of 20 matched-pair cadaveric scapulae were performed. Specimens were harvested and dissected free of soft tissue. SS and BB techniques were randomly assigned to specimens for matched-pair comparison with SB trials. A patient-specific instrument (PSI)-guided Latarjet procedure was performed on each scapula. Specimens were tested using a uniaxial mechanical testing device under cyclic loading (100 cycles, 1 Hz, 200 N/s) followed by a load-to-failure protocol (0.5 mm/s). Construct failure was defined by graft fracture, screw avulsion, and/or graft displacement of more than 5 mm. RESULTS: Forty scapulae from 20 fresh frozen cadavers with a mean age of 69.3 years underwent testing. On average, SS constructs failed at 537.8 N (SD 296.8), whereas BB constructs failed at 135.1 N (SD 71.4). SB constructs required a significantly greater load to fail compared with BB constructs (283.5 N, SD 162.8, P = .039). Additionally, SS (1.9 mm, IQR 0.87) had a significantly lower maximum total graft displacement during the cyclic loading protocol compared with SB (3.8 mm, IQR 2.4, P = .007) and BB (7.4 mm, IQR 3.1, P < .001) constructs. CONCLUSION: These findings support the potential of the SB fixation technique as a viable alternative to SS and BB constructs. Clinically, the SB technique could reduce the incidence of loading-related graft complications seen in the first 3 months of BB Latarjet cases. The study is limited to time-specific results and does not account for bone union or osteolysis.

Single-Stage Revision Reverse Shoulder Arthroplasty: Preoperative Planning, Surgical Technique, and Mixed Reality Execution.

Revision shoulder arthroplasty is increasing with the number of primary shoulder replacements rising globally. Complex primary and revisions of shoulder arthroplasties pose specific challenges for the surgeon, which must be addressed preoperatively and intraoperatively. This article aimed to present strategies for the management of revision of shoulder arthroplasties through a single-stage approach. Preoperatively, patient factors, such as age, comorbidities, and bone quality, should be considered. The use of planning software can aid in accurately evaluating implants in situ and predict bony anatomy that will remain after explantation during the revision surgery. The planning from such software can then be executed with the help of mixed reality technology to allow accurate implant placement. Single-stage revision is performed in two steps (debridement as first step, implantation and reconstruction as the second step), guided by the following principles: adequate debridement while preserving key soft tissue attachments (i.e., rotator cuff, pectoralis major, latissimus dorsi, deltoid), restoration of glenoid joint line using bone grafting, restoration of humeral length, reconstruction and/or reattachment of soft tissues, and strict compliance with the postoperative antibiotic regimen. Preliminary results of single-stage revision shoulder arthroplasty show improvement in patient outcomes (mean 1 year), successful treatment of infection for those diagnosed with periprosthetic joint infection, and improved cost-benefit parameters for the healthcare system.

All-Arthroscopic Muscle Slide and Advancement Technique to Repair Massive Retracted Posterosuperior Rotator Cuff Tears.

Symptomatic massive posterosuperior rotator cuff tears without glenohumeral joint arthritis and chronic medial retraction often are deemed "irreparable." These patients often are treated with alternative joint-sparing procedures including superior capsular reconstruction or tendon transfer procedures. Open and arthroscopic-assisted muscle advancement techniques allow maximal lateral tendon mobilisation during rotator cuff repair. In this report, we present an all-arthroscopic technique of complete supraspinatus and infraspinatus muscle scapular detachment and advancement in retracted massive posterosuperior rotator cuff tears. This allows for an anatomical tendon footprint reduction and tension-free repair.

Three-Dimensional Quantification of Glenoid Bone Loss in Anterior Shoulder Instability: The Anatomic Concave Surface Area Method.

BACKGROUND: Recurrent shoulder instability may be associated with glenoid erosion and bone loss. Accurate quantification of bone loss significantly influences the contemplation of surgical procedure. In addition, assessment of bone loss is crucial for surgical planning and accurate graft placement during surgery. PURPOSE: To quantify the concave surface area of glenoid bone loss by using 3-dimensional (3D) segmented models of the scapula and to compare this method with the best-fit circle and glenoid height/width methods, which use the glenoid rim for bone loss estimations. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 36 consecutive preoperative bilateral computed tomography scans of patients eligible for a primary Latarjet procedure were selected from our institutional surgical database (mean patient age, 29 ± 9 years; 31 men and 5 women). The 3D models of both scapulae were generated using medical segmentation software and were used to map the anatomic concave surface area (ACSA) of the inferior glenoid using the diameter of the best-fit circle of the healthy glenoid. Bone loss was calculated as a ratio of the difference between surface areas of both glenoids (healthy and pathological) against the anatomic circular surface area of the healthy glenoid (the ACSA method). These results were compared with bone loss calculations using the best-fit circle and glenoid height/width methods. Inter- and intraobserver reliability were also calculated. RESULTS: The mean (± SD) bone loss calculated using the ACSA, the best-fit circle, and glenoid height/width methods was 9.4% ± 6.7%, 14.3% ± 6.8%, and 17.6% ± 7.3%, respectively. The ACSA method showed excellent interobserver reliability, with an intraclass correlation coefficient (ICC) of 0.95 versus those for the best-fit circle (ICC, 0.71) and glenoid height/width (ICC, 0.79) methods. CONCLUSION: Quantification of instability-related glenoid bone loss is reliable using the 3D ACSA method.

Pedicled-lesser tuberosity osteotomy for glenohumeral joint exposure: a technical note and case report highlighting its use in allograft reconstruction of a large engaging reverse Hill-Sachs lesion after posterior shoulder dislocation.

Exposure of the humeral articular surface through an anterior approach to the shoulder for grafting humeral bone defects requires partial or complete detachment of the subscapularis tendon and traditionally is achieved through a subscapularis tenotomy, peel tuberosity osteotomy, or lesser tuberosity osteotomy. This case report presents a technique of performing a pedicled-lesser tuberosity osteotomy to allow adequate access for allograft reconstruction of a large reverse Hill-Sachs lesion after a traumatic posterior dislocation, to restore humeral head sphericity and prevent recurrent glenohumeral joint instability. The inferior subscapularis insertion is left intact leaving a periosteal sleeve and preserving the blood supply to the lesser tuberosity and humeral head, with the aim of improving healing of the osteotomy and preventing graft-related complications, such as resorption. Successful union of the pedicled-lesser tuberosity osteotomy and allograft was seen on a 6-month follow-upcomputed tomography scan, with adequate restoration of subscapularis function.

Computed tomographic evaluation of glenoid joint line restoration with glenoid bone grafting and reverse shoulder arthroplasty in patients with significant glenoid bone loss.

BACKGROUND: Restoration of native glenohumeral joint line is important for a successful outcome after reverse shoulder arthroplasty (RSA). The aims of this study were to quantify the restoration of glenoid joint line after structural bone grafting and RSA, and to evaluate graft incorporation, correction of glenoid version, and rate of notching. METHODS: This is a retrospective review of 21 patients who underwent RSA (20 primary, 1 revision) with glenoid bone grafting (15 autografts, 6 allografts). Grammont design implants and baseplate with long peg were used in all patients. Preoperative and postoperative 3D models were created using MIMICS 21.0. Preoperative defects were classified, and postoperative joint line restoration was assessed based on the lateral aspect of the base of the coracoid. Postoperative computed tomographic (CT) scans were evaluated for graft incorporation, version correction, and presence of notching. RESULTS: Preoperative glenoid defects were classified as massive (5%), large (29%), moderate (52%), and small (14%). The average preoperative version was 8° of retroversion. The average postoperative version was 5° of retroversion. The average preoperative medialization was noted to be 8.4 mm medial to native joint line or 0.6 mm (range -16.8 to 13.2) lateral to the coracoid base. The postoperative CT scans demonstrated a mean joint line at 12.1 mm (range 1.3-22.4) lateral to the coracoid base. At the 3-month follow-up, all patients demonstrated graft incorporation on CT scans. Graft osteolysis was observed on CT scan in 4.8% of patients at a mean follow-up of 19.5 months. DISCUSSION: Structural bone grafting of glenoid defect effectively re-creates the glenoid anatomy, restores glenoid bone stock, re-creates the true glenohumeral joint line, and corrects glenoid deformity. The use of bone grafting also allows lateralization of the baseplate and glenosphere, reducing the risk of severe scapular notching. CONCLUSION: Restoration of the glenoid joint line was achieved in all patients. Glenoid bone grafting is a viable option for restoring glenoid joint line in cases of significant glenoid defects encountered during RSA.

Arthroscopic Double-Layer Lasso Loop Technique to Repair Delaminated Rotator Cuff Tears.

PURPOSE: To evaluate the arthroscopic double-layer lasso loop repair technique for delaminated posterosuperior rotator cuff tears. METHODS: Forty-one patients underwent arthroscopic rotator cuff repair of a delaminated posterosuperior rotator cuff tear by the double-layer lasso loop technique. Their preoperative and postoperative clinical and functional scores were compared to evaluate surgical outcomes. The prerequisite for inclusion was a minimum follow-up period of 2 years. We excluded patients with a history of shoulder surgery before the double-layer lasso loop repair. RESULTS: Statistically significant improvements (P < .001) were found in the Constant score (54 vs 83) and University of California, Los Angeles functional score (6.4 vs 9.5). Pain and strength improved according to the Jobe test, bear-hug test, belly-press test, Gerber lift-off test, and external rotation test (P < .001). No significant difference in strength was noted between the operated and nonoperated sides. There was only 1 complete rerupture (3.1%), whereas 5 patients (15.6%) had partial ruptures. CONCLUSIONS: The arthroscopic double-layer lasso loop repair technique for delaminated posterosuperior rotator cuff tears is an effective procedure. Our series showed a low rerupture rate. At a mean follow-up of 44 months, postoperative recovery with resultant functional, pain, and patient satisfaction scores was good to excellent and was comparable with the nonoperated side. LEVEL OF EVIDENCE: Level IV, case series.