Influence of the rotator cuff tear pattern in shoulder stability after arthroscopic superior capsule reconstruction: a computational analysis.

OBJECTIVES: To assess the ability of the arthroscopic superior capsule reconstruction (SCR) in restoring glenohumeral stability in the presence of different preoperative patterns of irreparable rotator cuff tears (RCTs). METHODS: A computational musculoskeletal (MSK) model of the upper limb was used to simulate isolated SCR and to estimate the stability of the shoulder. Four patterns of preoperative irreparable RCTs were modeled: Supraspinatus (SSP); SSP â€‹+ â€‹Subscapularis (SSC); SSP â€‹+ â€‹Infraspinatus (ISP); and SSP â€‹+ â€‹SSC â€‹+ â€‹ISP. The muscles involved in the irreparable RCT were removed from the MSK model to simulate an irreparable full-thickness tear. In the MSK model, the muscle and joint forces were estimated for a set of upper limb positions, from four types of motions (abduction in the frontal plane, forward flexion in the sagittal plane, reaching behind the back, and combing the hair) collected in a biomechanics laboratory, through inverse dynamic analysis. The stability of the shoulder was estimated based on the tangential and compressive components of the glenohumeral joint reaction force. The comparison of pre- and post-operative conditions, for the four patterns of irreparable RCTs, with the healthy condition, was performed using ANOVA and Tukey's tests (statistical level of p â€‹< â€‹0.05). RESULTS: In the setting of an isolated irreparable SSP tear, SCR statistically significantly improved stability compared with the preoperative condition (p â€‹< â€‹0.001). For the irreparable SSP â€‹+ â€‹SSC pattern, a statistically significant loss in stability was observed (p â€‹< â€‹0.001) when SCR was applied. For the irreparable SSP â€‹+ â€‹ISP and SSP â€‹+ â€‹SSC â€‹+ â€‹ISP patterns, the postoperative condition increased shoulder stability, compared to the preoperative condition; however, the improvement was not statistically significantly different. CONCLUSION: Isolated SCR for irreparable RCTs extending beyond the SSP does not statistically significantly improve the stability of the glenohumeral joint. LEVEL OF EVIDENCE: Level IV.

Dynamic Anterior Stabilization of the Shoulder: Onlay Biceps Transfer to the Anterior Glenoid Using the Double Double-Pulley Technique.

The treatment of anterior glenohumeral instability includes several surgical options, ranging from soft tissue to bony procedures-open or arthroscopic. In arthroscopic dynamic anterior stabilization (DAS) of the shoulder, the long head of the biceps is transferred to the anterior glenoid through a subscapularis tendon split. The biceps may be fixed either in an inlay or in an onlay position. Inlay DAS theoretically increases anterior glenohumeral stability through 3 different effects: the hammock effect, sling effect, and the tensioning effect. Onlay DAS may additionally increase stability through a labroplasty effect, produced by the onlay positioning of the biceps on the anterior glenoid rim. The current technical note presents tips and tricks, and pearls and pitfalls, to reproducibly perform onlay DAS using all-suture anchors and the double double-pulley technique.

Onlay Dynamic Anterior Stabilization With Biceps Transfer for the Treatment of Anterior Glenohumeral Instability Produces Good Clinical Outcomes and Successful Healing at a Minimum 1 Year of Follow-Up.

Purpose: To report the results of the onlay dynamic anterior stabilization (DAS) using the long head of biceps (LHB) and the double double-pulley technique for the treatment of anterior glenohumeral instability (AGI) with ≤20% glenoid bone loss (GBL). Methods: From September 2018 to December 2021, patients with AGI and ≤20% GBL were enrolled in a prospective study on DAS and followed for a minimum of 1 year. The primary outcomes were Western Ontario Shoulder Instability Index, Rowe score, range of motion, and strength. The secondary outcomes were ability to return to play (RTP), RTP at same level, lack of recurrence of instability, successful LHB healing, and lack of complications. Magnetic resonance imaging was used to measure GBL, Hill-Sachs interval, glenoid track, and assess LHB integrity. Results: Eighteen consecutive patients underwent DAS. Fifteen patients had a minimum follow-up of 12 months (mean, 23.93 ± 13.67 months). In total, 12 were male and 3 female patients; 73.3% practiced recreational sports; mean age at surgery was 23.40 ± 6.53 years; mean number of dislocation episodes were 10.13 ± 8.42; mean GBL was 8.21 ± 7.39% (range, 0-20.24%); mean Hill-Sachs interval was 15.00 ± 2.96 mm; and mean glenoid track was 18.87 ± 2.57mm. The mean improvement in the Western Ontario Shoulder Instability Index and Rowe score (959.27 ± 386.70 and 74.00 ± 22.22 points) was significant (P < .001 and P < .001) and more than 6 times greater than the minimum clinically important difference. The mean improvement in active elevation, abduction, and external and internal rotation (23.00 ± 27.76°, 33.33 ± 43.78°, 8.33 ± 13.58°, and 0.73 ± 1.28 points) was significant (P = .006, P = .011, P = .032, and P = .044). RTP rate was 93.33%. RTP at same level was 60.00%. One patient with hyperlaxity had a redislocation (6.7% recurrence). No complications were reported. Each magnetic resonance imaging scan showed successful LHB healing to the anterior glenoid. Conclusions: At a minimum of 1-year follow-up, DAS produces significant and clinically important improvements in shoulder function, successful LHB healing, and is safe for the treatment of AGI with ≤20% GBL without severe hyperlaxity. Level of Evidence: IV, therapeutic case series.

Influence of Graft Positioning during the Latarjet Procedure on Shoulder Stability and Articular Contact Pressure: Computational Analysis of the Bone Block Effect.

The Latarjet procedure is the most popular surgical procedure to treat anterior glenohumeral (GH) instability in the presence of large anterior glenoid bone defects. Even though the placement of the bone graft has a considerable influence on its efficacy, no clear indications exist for the best graft position. The aim of this study was to investigate the influence of the medial-lateral positioning of the bone graft on the contact mechanics and GH stability due to the bone block effect. Four finite element (FE) models of a GH joint, with a 20% glenoid bone defect, treated by the Latarjet procedure were developed. The FE models differed in the medial-lateral positioning of the bone graft, ranging from a flush position to a 4.5 mm lateral position with respect to the flush position. All graft placement options were evaluated for two separate shoulder positions. Anterior GH instability was simulated by translating the humeral head in the anterior direction, under a permanent compressive force, until the peak translation force was reached. Joint stability was computed as the ratio between the shear and the compressive components of the force. The lateralization of the bone graft increased GH stability due to the bone block effect after a 3 mm lateralization with respect to the flush position. The increase in GH stability was associated with a concerning increase in peak contact pressure due to the incongruous contact between the articulating surfaces. The sensitivity of the contact pressures to the medial-lateral positioning of the bone graft suggests a trade-off between GH stability due to the bone block effect and the risk of osteoarthritis, especially considering that an accurate and consistent placement of the bone graft is difficult in vivo.

Combined Vertical, Horizontal, and Rotational Acromioclavicular Joint Stabilization: "Closing the Circle" Technique.

The biomechanical and anatomical complexity of the acromioclavicular joint makes its repair techniques particularly challenging. High rates of reduction subsidence and construction failures transversally affect both anatomic and nonanatomic repair techniques. The importance of addressing both vertical and horizontal instability has been highlighted in recent years. The authors aim to describe a surgical technique that combines vertical, horizontal, and rotational stabilization, in an attempt to restore the coracoacromioclavicular circle of stability.

Mechanical consequences at the tendon-bone interface of different medial row knotless configurations and lateral row tension in a simulated rotator cuff repair.

PURPOSE: Little is known about the direct influence of different technical options at the rotator cuff tendon-bone interface (TBI) and, more specifically, at the medial bearing row (MBR), regarding local contact force, area and pressure. We evaluated the mechanical repercussions of different medial row anchor configurations for that setting using different values of tension in the lateral row anchors. METHODS: Knotless transosseous equivalent (TOE) rotator cuff repairs with locked versus nonlocked medial anchors and single versus double-hole suture passage were tested in a synthetic rotator cuff mechanical model, using 2 different values of lateral row tension. Contact force, area, pressure, peak force and MBR force were compared at the simulated TBI using a pressure mapping sensor. RESULTS: When compared to locked anchors, medial row sliding configurations generate lower values for all the above-mentioned parameters. The use of double-hole suture passage in the medial cuff generated slightly higher values contact area regardless of lateral row tension. At higher lateral row tension values, lower values of the remaining parameters, including MBR force, were found when compared to single-hole suture passage. Lateral row anchor tension increase induced an increase of all parameters regardless of the medial row configuration and TBI contact force and MBR force were the most susceptible parameters, regardless of the medial row pattern. CONCLUSION: Medial row mechanism, suture configuration and lateral row tension interfere with the mechanical force, area and pressure at by TBI. Lateral row tension increase is a major influencer in those parameters. These results can help surgeons choose the right technique considering its mechanical effect at the TBI.

Donor-Site Morbidity After Autologous Fascia Lata Harvest for Arthroscopic Superior Capsular Reconstruction: A Midterm Follow-up Evaluation.

BACKGROUND: Autologous fascia lata (AFL) graft use in arthroscopic superior capsular reconstruction (ASCR) is effective for the treatment of irreparable rotator cuff tears (RCTs). Although donor-site morbidity (DSM) is a recurrent argument against AFL graft use, scientific evidence for this argument is lacking. PURPOSE: To report the midterm clinical follow-up evaluation of DSM in ASCR using minimally invasively harvested AFL grafts and compare thigh function and patient satisfaction with those of an unharvested control group. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Of 66 consecutive patients who underwent ASCR using a minimally invasively harvested AFL graft, 39 patients with a minimum follow-up of 24 months were retrospectively evaluated (ASCR group) and compared with 39 randomly selected patients who underwent arthroscopic RCT repair by the same surgeons (control group). The functional outcomes of both thighs were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Patient satisfaction was evaluated using the Patient Scar Assessment Questionnaire (PSAQ) and a subjective questionnaire. Pain was quantified using a visual analog scale (VAS). RESULTS: The ASCR group had a mean age of 65 years (range, 51-77 years) and a mean follow-up of 47 months (range, 24-66 months). The WOMAC score in the harvested thigh differed by 0.8% from that in the contralateral thigh (P = .002). The mean PSAQ score differed by 6 points from the minimum PSAQ score (P < .001). Overall, 95% of the patients indicated that they would undergo the same surgery again and that the shoulder outcome compensated for the thigh symptoms. There was no significant association between the presence of residual thigh symptoms and the willingness to undergo the same surgery again (P = .354). The mean VAS score in the harvested thigh was 0.6 (range, 0-5). There was no significant difference in the average WOMAC score or VAS score between groups (P = .684 and P = .148, respectively). CONCLUSION: Despite the proportion of residual symptoms, the associated functional effects were small and not clinically significant, and the vast majority of patients were accepting of the harvest symptoms given the improvement in shoulder function.

Shoulder Positioning during Superior Capsular Reconstruction: Computational Analysis of Graft Integrity and Shoulder Stability.

The shoulder position during fixation of the graft may be a key factor impacting the outcome of arthroscopic superior capsular reconstruction (ASCR) in irreparable rotator cuff tears (IRCTs). However, biomechanical evidence regarding this effect is lacking. The aim of this study was to evaluate the influence of the shoulder position during fixation of the graft on shoulder stability and graft tear risk in ASCR. A 3-D musculoskeletal model of the upper limb was modified to account for the fixation of the graft in ASCR, assuming a full-thickness tear of the supraspinatus tendon. The concomitant tenotomy of the long head of the biceps (LHB) tendon was also studied. The biomechanical parameters evaluated included the strain of the graft and the glenohumeral joint reaction force (GH JRF), which were used to evaluate graft integrity and shoulder stability, respectively. Fixation of the graft considering abduction angles greater than 15° resulted in a high risk for graft tearing when the arm was adducted to the side of the trunk. For abduction angles below 15°, the mean shoulder stability improved significantly, ranging between 6% and 20% (p < 0.001), compared with that in the preoperative condition. The concomitant tenotomy of the LHB tendon resulted in loss of stability when compared to ASCR with an intact LHB tendon. The position of the shoulder during fixation of the graft has a significant effect on shoulder stability and graft tear risk after ASCR in IRCTs. This study provides new and important information regarding the role of shoulder positioning during fixation of the graft.

Proximal and mid-thigh fascia lata graft constructs used for arthroscopic superior capsule reconstruction show equivalent biomechanical properties: an in vitro human cadaver study.

BACKGROUND: The proximal fascia lata (FL) graft construct used for arthroscopic superior capsule reconstruction (ASCR) is openly harvested, whereas the mid-thigh FL graft construct is minimally invasively harvested. The purpose of the current study was to compare the biomechanical properties of proximal thigh and mid-thigh-harvested FL graft constructs used for ASCR. The hypothesis was that, despite the different morphological characteristics of the proximal thigh and mid-thigh FL graft constructs used for ASCR, their biomechanical properties would not significantly differ. This information may assist orthopedic surgeons in the choice of the harvest location, technique, and type of graft construct for ASCR. METHODS: Forty FL specimens, 20 proximal thigh and 20 mid-thigh, were harvested from the lateral thighs of 10 fresh human cadavers (6 male, 4 female; average age, 58.60 ± 17.20 years). The thickness of each 2-layered proximal thigh and 6-layered mid-thigh FL graft construct was measured. Each construct was mechanically tested in the longitudinal direction, and the stiffness and Young's modulus were computed. Data were compared by Welch's independent t-test and analysis of variance, and statistical significance was set at P < .05. RESULTS: The average thickness of the proximal thigh FL graft construct (7.17 ± 1.97 mm) was significantly higher than that of the mid-thigh (5.54 ± 1.37 mm) [F (1,32) = 7.333, P = .011]. The average Young's modulus of the proximal thigh and mid-thigh graft constructs was 32.85 ± 19.54 MPa (range, 7.94 - 75.14 MPa; 95% confidence interval [CI], 23.71 - 42.99) and 44.02 ± 31.29 MPa (range, 12.53 -120.33 MPa; 95% CI, 29.38 - 58.66), respectively. The average stiffness of the proximal thigh and mid-thigh graft constructs was 488.96 ± 267.80 N/mm (range, 152.96 - 1086.49 N/mm; 95% CI, 363.63 - 614.30) and 562.39 ± 294.76 N/mm (range, 77.46 - 1229.68 N/mm; 95% CI, 424.44 - 700.34), respectively. There was no significant difference in the average Young's modulus or stiffness between the proximal thigh and mid-thigh graft constructs (P = .185 and P = .415, respectively). CONCLUSION: Despite the different morphological characteristics of the proximal thigh and mid-thigh FL graft constructs used for ASCR, their Young's modulus and stiffness did not significantly differ.

All-Suture Anchor Dynamic Anterior Stabilization Produced Successful Healing of the Biceps Tendon: A Report of 3 Cases.

CASES: Three patients (age, 15-34 years) who had a history of chronic traumatic anteroinferior glenohumeral instability (2-10 dislocations) and preoperatively documented Bankart and Hill-Sachs lesions underwent all-arthroscopic trans-subscapular transposition of the long head of the biceps that was fixed on the anteroinferior glenoid using a novel double double-pulley all-suture anchor method that has not been reported previously. CONCLUSION: Excellent 12-month clinical and imaging outcomes, with substantial improvements in the Western Ontario Shoulder Index and the Rowe score in the first consecutive patients who underwent this original technical variant of dynamic anterior stabilization and the surgical pearls and pitfalls are described in detail.

Fascia Lata Autograft Versus Human Dermal Allograft in Arthroscopic Superior Capsular Reconstruction for Irreparable Rotator Cuff Tears: A Systematic Review of Clinical Outcomes.

PURPOSE: To determine the clinical outcomes of arthroscopic superior capsular reconstruction (ASCR) using either fascia lata autograft or human dermal allograft for irreparable rotator cuff tears (IRCTs). METHODS: A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines by searching the MEDLINE, Embase, and Cochrane Library databases through January 31, 2019. The inclusion criteria were as follows: 5 or more consecutive patients who underwent ASCR for IRCTs; clinical outcome measures reported at a minimum follow-up of 12 months; and magnetic resonance imaging assessment at a minimum follow-up of 6 months. The methodologic quality was evaluated using the Methodological Index for Non-randomized Studies (MINORS). A narrative synthesis of data was performed. Mean outcome improvements were compared with minimal clinically important differences. RESULTS: We identified 7 eligible studies that included 344 shoulders in 338 patients who underwent ASCR for IRCTs (all Level IV studies). The mean MINORS score was 12.3 ± 1.60. Of the 7 studies, 5 had a high risk of bias (MINORS score ≤12): 2 studies using only fascia lata autograft and 3 studies using only human dermal allograft. The mean age of patients ranged from 59.4 to 66.9 years. The mean follow-up time ranged from 12 to 48 months. All studies reported statistically significant and clinically important mean improvements in active elevation (range of means, 28°-56°), the Constant score (range of means, 12-47.1 points), or the American Shoulder and Elbow Surgeons score (range of means, 29.3-56 points). In total, 218 shoulders underwent postoperative magnetic resonance imaging. The graft tear rate reported in studies using fascia lata autograft (181 shoulders) ranged from 5% to 32%, whereas the values reported in studies using human dermal allograft (37 shoulders) ranged from 20% to 75%. CONCLUSIONS: ASCR using either fascia lata autograft or human dermal allograft leads to significant and clinically important improvements in clinical outcomes in IRCT patients at 12 months or later. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

Minimally invasive fascia lata harvesting in ASCR does not produce significant donor site morbidity.

PURPOSE: The aim of this study was to prospectively evaluate donor site morbidity in arthroscopic superior capsular reconstruction using a minimally invasive harvested fascia lata autograft. METHODS: Fifteen consecutive patients underwent arthroscopic superior capsular reconstruction by the senior author using a fascia lata autograft harvested in a minimally invasive fashion. All patients were prospectively evaluated at 1 week, 6 and 18 months postoperatively. The subjects' body mass index, age, actual or previous corticosteroid therapy history and active smoking habits were evaluated. Functional outcomes were assessed by the non-arthritic hip score applied to the harvested and contralateral thighs. Every patient completed standardized subjective satisfaction questionnaires at all evaluations. The median patient age was 65.5 years (range 47-77). Nine patients (60%) were females, and six (40%) were males. One patient (6.7%) was within the normal range of weight, nine (60%) were overweight, four (27%) were obese, and one (6.7%) was extremely obese. Two patients (13%) were active smokers. No patients had an active or previous record of corticosteroid therapy. No patients required postoperative lower limb physical therapy. RESULTS: In terms of overall and cosmetic satisfaction, most patients reported that they were satisfied or very satisfied at all evaluations, and the proportion of very satisfied patients increased over time (p < 0.001). The harvested thigh's functional scores were 91% (p = 0.003) and 94% (p = 0.008) of the healthy thigh's score at 6 and 18 months, respectively. The complications reported were mild, and their proportions decreased in the first 18 months after surgery (p = 0.04). CONCLUSIONS: The minimally invasive fascia lata harvesting technique for arthroscopic superior capsular reconstruction leads to donor site satisfactory subjective results and good functional outcomes at 18 months after surgery. According to these findings, donor site morbidity is not a valid argument against the use of this autograft for arthroscopic superior capsular reconstruction. LEVEL OF EVIDENCE: Case series, level IV.

Arthroscopic Superior Capsular Reconstruction With a Minimally Invasive Harvested Fascia Lata Autograft Produces Good Clinical Results.

BACKGROUND: Painful dysfunctional shoulders with irreparable rotator cuff tears (IRCTs) in active patients are a challenge. Arthroscopic superior capsular reconstruction (ASCR) is a new treatment option originally described using a fascia lata autograft harvested through an open approach. However, concerns about donor site morbidity have discouraged surgeons from using this type of graft. HYPOTHESIS: ASCR using a minimally invasive harvested fascia lata autograft produces good 6-month and 2-year shoulder outcomes in IRCTs, with low-impact thigh morbidity at 2 years. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From 2015 to 2016, a total of 22 consecutive patients (mean age, 64.8 ± 8.6 years) with chronic IRCTs (Hamada grade 1-2; Goutallier cumulative grade ≥3; Patte stage 1: 2 patients; Patte stage 2: 6 patients; Patte stage 3: 14 patients) underwent ASCR using a minimally invasive harvested fascia lata autograft. All patients completed preoperative and 6-month evaluations consisting of the Simple Shoulder Test (SST), subjective shoulder value (SSV), Constant score (CS), range of motion (ROM), acromiohumeral interval (AHI), and magnetic resonance imaging. Twenty-one patients completed the 2-year shoulder and donor site morbidity assessments. RESULTS: The mean active ROMs improved significantly (P < .001): elevation, from 74.8° ± 55.5° to 104.5° ± 41.9° (6 months) and 143.8° ± 31.7° (2 years); abduction, from 53.2° ± 43.3° to 86.6° ± 32.9° (6 months) and 120.7° ± 37.7° (2 years); external rotation, from 13.2° ± 18.4° to 27.0° ± 16.1° (6 months) and 35.6° ± 17.3° (2 years); and internal rotation, from 1.2 ± 1.5 points to 2.6 ± 1.5 points (6 months) and 3.8 ± 1.2 points (2 years). The mean functional shoulder scores improved significantly (P < .001): SST, from 2.1 ± 2.9 to 6.8 ± 3.5 (6 months) and 8.6 ± 3.5 (2 years); SSV, from 33.0% ± 17.4% to 55.7% ± 25.6% (6 months) and 70.0% ± 23.0% (2 years); CS, from 17.5 ± 13.4 to 42.5 ± 14.9 (6 months) and 64.9 ± 18.0 (2 years). The mean shoulder abduction strength improved significantly (P < .001) from 0.0 to 1.1 ± 1.4 kg (6 months) and 2.8 ± 2.6 kg (2 years). The mean AHI improved from 6.4 ± 3.3 mm to 8.0 ± 2.5 mm (6 months) and decreased to 7.1 ± 2.5 mm (2 years). This 0.7 ± 1.5-mm overall decrease was statistically significant (P = .042). At 6 months, 20 of 22 patients (90.9%) had no graft tears. At 2 years, 12 of 21 patients (57.1%) were bothered by their harvested thigh, 16 (76.2%) noticed donor site changes, 16 (76.2%) considered that the shoulder surgery's end result compensated for the thigh's changes, and 18 (85.7%) would undergo the same surgery again. CONCLUSION: ASCR using a minimally invasive harvested fascia lata autograft produced good 6-month and 2-year shoulder outcomes in IRCTs, with low-impact thigh morbidity at 2 years.