Editorial Commentary: Collagen Bridging of Massive Rotator Cuff Tears Using Fascia Lata Autograft Could Provide a Lasting Solution.

Shoulder rotator cuff tears are ideally primarily repaired, but large and massive, chronic, and/or retracted tears result in challenges. In response, innovative solutions include superior capsular reconstruction, tendon transfer, subacromial balloon spacer placement, tuberoplasty, partial repair, and marginal convergence. A recent innovation is to use collagen tissue to bridge repair of compromised tendon. Recent research using fascia lata autograft for supraspinatus tendon reconstruction in a rat model has shown positive outcomes with structural similarity to the normal muscle-tendon interface, decreased fatty infiltration, and increased type I and III collagen, suggesting enhanced mechanical strength. In human subjects, the advantages of autograft outweigh harvest-site morbidity, noting that Dacron, Teflon, and xenograft show poor results. Ideally, a graft might be composed of a degradable scaffold, possess mechanical strength, and amalgamate stem cells, growth factors, and matrix proteins to facilitate host-tissue integration.

Improved Acromiohumeral Distance Independently Predicts Better Outcomes After Arthroscopic Superior Capsular Reconstruction Graft Tears.

PURPOSE: To identify independent factors responsible for the poor outcomes after a graft tear after arthroscopic superior capsular reconstruction (ASCR). METHODS: Patients who underwent ASCR for massive rotator cuff tears between January 2013 and July 2021were reviewed. Based on the achievement of the minimal clinically important differences for clinical outcome measures at the final follow up, patients were divided into the good outcome (GO) and poor outcome (PO) groups. The minimal clinically important differences were calculated as the values equal to one-half of the standard deviation of the changes in outcome scores between the preoperative baseline and the latest follow-up. Pre- and final follow-up variables included demographics, American Shoulder and Elbow Surgeons (ASES) score, Constant score, visual analog scale (VAS) score, range of motion, Preoperative and postoperative 1-year radiological variables were analyzed using MRIs, including anteroposterior (AP) and mediolateral (ML) tear sizes, subscapularis tear, acromiohumeral distance (AHD), and degree of fatty degeneration. Logistic regression analysis was performed to identify the significant predictors of poor outcomes. RESULTS: A total of 33 patients who underwent ASCR presented with graft tears, which were confirmed by postoperative 1-year magnetic resonance imaging (MRI), and had a minimum follow-up duration of 2 years after surgery were enrolled. The GO group demonstrated significantly greater improvements in functional outcomes compared with the PO group (ASES: 83.5 ± 11.8 vs. 64.0 ± 20.4, P = 0.004; Constant: 67.6 ± 5.7 vs. 57.1 ± 9.8, P <0.001; and VAS: 0.9 ± 1.2 vs. 2.4 ± 2.0, P = 0.026). The postoperative 1-year AHD showed significant improvement in the GO group (3.1 ± 1.2 vs. 6.1 ± 1.4, P <0.001) but no change in the PO group (3.4 ± 1.3 vs. 4.2 ± 0.9, P = 0.074) postoperatively. Multivariate logistic regression analysis indicated that a decreased postoperative 1-year AHD (OR, 0.145; P = 0.019) was associated with a poor outcome after a graft tear. CONCLUSION: A narrow postoperative 1-year AHD was identified as the most importantindependent risk factor indicating poor clinical outcomes after a graft tear post-ASCR, which was related to a larger tear and loss of integrity between the grafts and infraspinatus at 1 year postoperatively. LEVEL OF EVIDENCE: Level IV.

Effect of age and gender in rates of achieving minimal clinically important difference and patient-acceptable symptom state 2 years after arthroscopic superior capsular reconstruction.

PURPOSE: This study aimed to evaluate patient-reported outcome measures (PROMs) and the effects of gender and age on achieving clinically significant outcomes in patients undergoing arthroscopic superior capsular reconstruction (ASCR) with a minimum 2-year follow-up. METHODS: Patients undergoing ASCR for irreparable rotator cuff tear between 2013 and 2020 were reviewed. Preoperative and minimum 2-year postoperative PROMs were collected, including American Shoulder and Elbow Surgeons (ASES), Constant, single assessment numeric evaluation (SANE), and visual analog scale (VAS) scores. Minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) were calculated for each functional score and analyzed according to age and gender. The percentages of patients achieving MCID and PASS were recorded. RESULTS: The study included 83 patients, with a mean follow-up of 3.5 ± 1.4 years. Significant improvements were found in ASES, Constant, SANE, and VAS for all groups based on gender and age. Based on receiver-operating characteristic curves, all scores had acceptable areas under the curve for PASS. Values for PASS and MCID were 81.5 and 10.3 for ASES; 61.5 and 6.2 for Constant; 82.5 and 11.5 for SANE and 1.5 and 1.1 for VAS, respectively. Analysis of achieving MCID and PASS showed no difference between the groups in the majority of outcome measures. However, female patients achieved the SANE thresholds for PASS at significantly higher rates than male patients. Patients ≥65 years old achieved ASES and Constant thresholds for MCID at significantly higher rates than patients ˂65 years old. CONCLUSION: Most patients achieved MCID and PASS at a 2-year follow-up. Patients showed comparable rates of MCID and PASS achievement on most outcome tools based on age and gender. Female patients achieved PASS on SANE at significantly higher rates than male patients and older patients achieved MCID on ASES and Constant at higher rates than young patients. Thus, age is a stronger factor for achieving MCID than gender. LEVEL OF EVIDENCE: Level II.

Preoperative magnetic resonance imaging rotator cuff tendon stump classification correlates with the surgical outcomes following superior capsular reconstruction.

HYPOTHESIS: This study aimed to investigate the correlation between rotator cuff stump classification and postoperative outcomes after superior capsular reconstruction (SCR). METHODS: A total of 75 patients who underwent SCR between June 2013 and May 2021 were included in this study. Based on stump classification using the signal intensity ratio of the tendon rupture site to the deltoid muscle in the coronal view of preoperative T2-weighted, fat-suppressed magnetic resonance imaging scans, the patients were classified into types 1, 2, and 3 with ratios of <0.8, 0.8-1.3, and >1.3 (44, 17, and 14 patients, respectively). The American Shoulder and Elbow Surgeons (ASES), Constant, and visual analog scale (VAS) scores for pain and range of motion were evaluated at a minimum of 1 year of follow-up postoperatively. The acromiohumeral distance and rotator cuff arthropathy according to the Hamada classification were assessed on plain radiography. The graft integrity was evaluated by magnetic resonance imaging at 3 and 12 months postoperatively and annually thereafter. RESULTS: Clinical and radiological outcomes were significantly improved after SCR. In comparison with type 2 and 3 patients, type 1 patients had significantly higher ASES scores (type 1, 2, and 3 = 84 ± 10, 75 ± 15, and 76 ± 14; all P = .014), Constant scores (type 1, 2, and 3 = 65 ± 5, 61 ± 9, and 56 ± 13; all P = .005), and forward flexion (type 1, 2, and 3 = 155 ± 10, 154 ± 15, and 145 ± 13; all P = .013). However, these statistical differences between groups were below the established minimum clinically important difference values for the ASES and Constant scores after rotator cuff repair. The graft failure rate after surgery was lower in the type 1 group than that in the other 2 groups; however, the difference was not statistically significant (P = .749). CONCLUSION: Patients with stump classification type 1 showed significantly better functional scores (ASES and VAS scores) and forward flexion; however, the clinical importance of these differences may be limited. Stump classification may be useful for predicting postoperative clinical outcomes.

Arthroscopic assessment for lateral collateral ligament complex deficiency of the elbow: a cadaveric study.

PURPOSE: To evaluate whether elbow instability due to lateral collateral ligament complex injury can be assessed reliably through arthroscopy. METHODS: Eight fresh human cadaveric elbows were placed in a simulated lateral decubitus position. The radiocapitellar joint (RCJ) gap and ulnohumeral joint (UHJ) gap (mm) were measured with different sizes of probes from the posterolateral viewing portal. The elbow was 90 degrees flexed with neutral forearm rotation for RCJ gap measurement and 30 degrees flexed with full supination for UHJ gap measurement. Sequential testing was performed from Stage 0 to Stage 3 (Stage 0: intact; Stage 1: the release of the anterior 1/3 LCL complex; Stage 2: the release of the anterior two thirds of the LCL complex; and Stage 3: the release of the entire LCL complex) on each specimen. The mean gap of RCJ and lateral UHJ was used for the comparison between stages with the intact elbow. RESULTS: The mean RCJ gap distance in Stage 2 and Stage 3 was significantly increased compared to that in Stage 0 (Stage 0 vs. Stage 2: P = .008; Stage 0 vs. Stage 3: P = .010). The mean UHJ gap distance of Stage 1, Stage 2, and Stage 3 was significantly increased compared to that in Stage 0 (Stage 0 vs. Stage 1: P = 0.025; Stage 0 vs. Stage 2: P = .010; Stage 0 vs. Stage 3: P = .011). In contrast, the release of the anterior 1/3 of the LCL complex (Stage 1) was not significantly increased compared to the mean joint gap distance of RCJ (P = .157). CONCLUSION: Arthroscopic measurement of joint gap widening in RCJ and UHJ is a reliable assessment method to detect LCL complex deficiency that involves the anterior two thirds or more.

Anterior radial head subluxation in primary elbow osteoarthritis.

PURPOSE: To investigate elbows with primary osteoarthritis (OA) for the presence of anterior radial head subluxation. METHODS: A total of 71 patients with elbow osteoarthritis and 45 with lateral epicondylitis were initially identified. The baseline characteristics and preoperative elbow X-rays of consecutive patients that had been clinically confirmed with elbow OA or lateral epicondylitis between March 2011 and January 2020 were then retrospectively reviewed. The radiocapitellar ratio (RCR; the ratio of the displacement of the radial head about the diameter of the capitulum) was calculated using lateral views. These RCR values were compared between the OA and lateral epicondylitis cases. RESULT: A significant increase was detected in RCR values between patients in elbow OA and the control group (13.2% (± 10.6) vs -1.2% (± 6.8), P<0.001). Based on receiver operating characteristic curves, RCR values had an excellent area under the curve (0.89) for the detection of elbow OA (Youden index, 0.69; sensitivity, 89%; specificity, 80%). Based on the ROC curve, the cutoff value of RCR was 0.04. Patients with RCR ≥ 0.04 had a significantly higher proportion of cases with elbow OA (risk ratio, 31.50 [95% CI, 11.17-88.82]) than those with RCR ˂ 0.04 (P ˂ 0.001). CONCLUSION: Radial head subluxation is a radiographic finding associated with elbow OA and RCR ≥ 0.04 could be used as an aetiological factor for elbow OA diagnosis.

Does body mass index affect outcomes following arthroscopic superior capsular reconstruction using fascia lata autograft for massive irreparable rotator cuff tear?

PURPOSE: This study aimed to evaluate the effect of increased body mass index (BMI) on patient-reported outcomes (PROs) and clinically significant outcomes (CSOs) obtained > two years postoperatively following arthroscopic superior capsular reconstruction (ASCR). METHODS: A retrospective study was conducted on patients who underwent ASCR with a minimum two year follow-up. All patients were divided into normal (BMI < 25.0), overweight (BMI 25-30.0), and obese (BMI ≥ 30) according to preoperative BMI. Patients were assessed using the PROs preoperatively and at six months, one year, and two years postoperatively, including the visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES), and Constant-Murley scores. The time required to achieve each CSO was analyzed and compared. Multivariate analyses evaluated the predictor variables and time required to achieve CSOs. RESULTS: This study included 63 patients with a mean age of 64.8 ± 8.6 years, including 31 normal BMI, 25 overweight, and seven obese patients. Significant improvements in VAS and ASES scores after ASCR were observed in all three groups. Normal and overweight patients had significant improvements in the Constant score; however, no difference was observed in obese patients. No significant difference was observed in the probability distributions of CSOs between the BMI groups. Similarly, no significant differences were observed in the probability distributions of the CSOs, ASES, and Constant scores at each time point, among the BMI groups. CONCLUSION: Patients in the normal and overweight groups had significant improvements in the VAS, ASES, and Constant scores after ASCR. Patients in the obese group had a significant improvement in VAS score; however, there is no difference for the ASES and Constant scores in the obese group. However, no differences were observed in all PROMs and the likelihood of achieving CSOs among the different BMI groups.

Remplissage in Addition to Arthroscopic Bankart Repair for Shoulder Instability With On-Track Hill-Sachs Lesions Reduces Residual Apprehension Without External Rotation Limitation.

PURPOSE: To evaluate the role of remplissage as an adjunct to Bankart repair in patients with recurrent anterior shoulder dislocation combined with on-track Hill-Sachs lesion. METHODS: Arthroscopic Bankart repair with remplissage data (December 2018-2020) were collected (BR group). Inclusion criteria were (1) recurrent anterior shoulder dislocation, (2) on-track Hill-Sachs lesion, (3) minimal/subcritical glenoid bone loss (<17%), and (4) postoperative follow-up >1 year. Exclusion criteria were (1) revision surgery, (2) first dislocation with acute glenoid rim fracture, and (3) combined with other surgery. The control group was identified in Bankart repair-only cohort (B group). All patients were evaluated preoperatively, and at 3 weeks, 6 weeks, 3 months, 6 months, and then annually postoperatively. Visual analogue scale for pain, Self-Assessment Numerical Evaluation, American Shoulder and Elbow Surgeons Shoulder score, ROWE, and Western Ontario Shoulder Instability were evaluated at preoperative and final follow-up. Residual apprehension experience and external rotation deficit were evaluated. Patients, who were followed-up for more than 1 year, were asked how often they experienced any subjective apprehension in 4 grades (1: always, 2: frequently, 3: occasionally, 4: never). Patients who had a history of recurrent dislocation or revision surgery were investigated. RESULTS: In total, 53 patients (B, 28; BR, 25) were included. At final follow-up, both groups showed improvement in 5 clinical scores postsurgery (P < .001). The BR group showed greater ROWE scores than the B group (B: 75.2 ± 13.6, BR: 84.4 ± 10.8; P = .009). Residual apprehension patient ratio (B: 71.4% [20/28], BR: 32% [8/25]; P = .004) and the mean subjective apprehension grade (B: 3.1 ± 0.6, BR: 3.6 ± 0.6; P = .005) showed statistically significant difference, whereas no patients in either group experienced external rotation deficit (B: 14.8 ± 12.9°, BR: 18.0 ± 15.2°, P = .420). Only 1 patient in the B group had not responded to surgery, with dislocation recurrence (P = .340). CONCLUSIONS: Remplissage with arthroscopic Bankart repair in on-track Hill-Sachs lesion has a role in reducing residual apprehension without external rotation limitation. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

Cancellous bone should not be exposed during medialized rotator cuff repair based on bone-to-tendon healing in a rat mode.

PURPOSE: To compare the biological bone-to-tendon healing using three different medialized bone bed preparation techniques (i.e. cortical bone exposure, cancellous bone exposure, and no cartilage removal) in a rat model of medialized rotator cuff repair. METHODS: Twenty-one male Sprague-Dawley rats with 42 shoulders were subjected to bilateral supraspinatus tenotomy from the greater tuberosity. The rotator cuff was repaired using medialized anchoring with the cortical bone exposed, the cancellous bone exposed, or no cartilage removed. Four and three rats in each group were killed for biomechanical testing and histological evaluation, respectively, at postoperative 6 weeks. RESULTS: All rats survived until the end of the study, but one infected shoulder in the cancellous bone exposure group was excluded from further analysis. Compared with the cortical bone exposure and no cartilage removal groups, the rotator cuff healing of the cancellous bone exposure group showed significantly lower maximum load (cancellous bone exposure group: 26.2 ± 2.3 N, cortical bone exposure group: 37.6 ± 7.9 N, no cartilage removal group: 34.6 ± 7.2 N, P = 0.005 and 0.029) and less stiffness (cancellous bone exposure group: 10.5 ± 2.4 N/mm, cortical bone exposure group: 17.4 ± 6.7 N, no cartilage removal group: 16.0 ± 3.9 N, P = 0.015 and 0.050) at postoperative 6 weeks. In all three groups, the repaired supraspinatus tendon healed towards the original insertion rather than the medialized insertion. The cancellous bone exposure group showed inferior fibrocartilage formation and insertion healing. CONCLUSIONS: The medialized bone-to-tendon repair strategy does not guarantee complete histological healing, and the removal of excessive bony structure impairs bone-to-tendon healing. This study concludes that surgeons should not expose the cancellous bone during the medialized rotator cuff repair.

Absorbable suture knots on the supraspinatus tendon prevent adverse effects of nonabsorbable suture knots in a rat model.

PURPOSE: To compare the absorbable and nonabsorbable suture knots on the tendon on bone-to-tendon healing during the early phase in a rat rotator cuff tear (RCT) model. METHODS: Fifty-two male Sprague-Dawley rats (10 weeks old; mean weight, 380 g) were used in this study, and 51 of them were randomly assigned into three groups: absorbable suture group (ASG, n = 22), nonabsorbable suture group (NSG, n = 22), and sham surgery group (SSG, n = 7), and the remaining rat was used to take surgical pictures. Bilateral supraspinatus tendon tears were created and repaired immediately in ASG and NSG. Three rats from ASG and NSG were killed for Western blot and histological evaluation at 3 days, 1 week, and 4 weeks after surgery. At 4 weeks, four rats from each group were killed for biomechanical test, and three rats from SSG were used for histological evaluation. RESULTS: Absorbable suture knots on the tendon completely degraded at 4 weeks. However, nonabsorbable suture knots remained intact between the tendon and articular side. ASG showed a stronger inflammatory reaction at 3 days and 1 week, but a weaker reaction at 4 weeks as confirmed by gross observation and Western blot. Besides, ASG showed superior biomechanical properties in terms of maximum load to failure and stiffness at 4 weeks. Modified Bonar score revealed superior maturity for tissue healing in ASG to that in NSG at 4 weeks. Furthermore, inferior bone-to-tendon interface and weakest link formation were observed in NSG on histologic images. CONCLUSION: Absorbable suture knots on the tendon contributed to better mechanical properties compared with the nonabsorbable one after rotator cuff repair.

Postoperative MRI signal intensity correlates functional outcomes after superior capsular reconstruction.

PURPOSE: Superior capsular reconstruction (SCR) using fascia lata autograft has been performed for irreparable rotator cuff tear recently. The signal-to-noise quotient (SNQ) of the graft on magnetic resonance imaging (MRI) may reflect the degree of graft maturity and healing. However, how SNQ changes with graft remodelling and time and whether this change correlates with postoperative clinical outcomes after SCR remain unknown. This study aimed to explore the correlation between SNQ of the fascia lata autograft and clinical functional outcomes after SCR. METHODS: Patients with irreparable posterosuperior rotator cuff tear undergoing SCR using fascia lata autograft between 2013 and 2017 were retrospectively analysed. For clinical outcomes, the American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, Single Assessment Numeric Evaluation (SANE), and Visual Analogue Scale (VAS) for pain and range of motion (ROM; forward flexion and external rotation) were evaluated at postoperative 6 and 12 months. Signal intensity of the humeral, mid-substance, and glenoid sites and background were measured to calculate the SNQ values on follow-up MRI at 3 and 12 months. The correlations between clinical outcomes and SNQ at different time points were then analysed. RESULTS: A total of 15 patients were enrolled in the study. The mean postoperative VAS score significantly increased at postoperative 6 months and significantly decreased at postoperative 12 months. Except for forward flexion, all other functional outcomes were improved at postoperative 6 months. Analysis of MRI showed SNQ at the humeral (SNQh), mid-substance, and glenoid sites decreased from postoperative 3 to 12 months with a statistical significance detected in SNQh (P < 0.01). Correlation analyses showed that the SNQh values negatively correlated with VAS, ASES, Constant-Murley score, SANE, ROM (forward flexion), and ROM (external rotation) (all P < 0.05). CONCLUSION: SNQ of the fascia lata autograft decreased with time in patients receiving SCR. SNQ at the humeral site was negatively correlated with clinical outcomes. LEVEL OF EVIDENCE: III.

Time required to achieve clinically significant outcomes after arthroscopic superior capsular reconstruction.

PURPOSE: To investigate the time-dependent nature of clinically significant outcomes, including the minimal clinically important difference (MCID), substantial clinical benefit, and Patient Acceptable Symptomatic State (PASS) after arthroscopic superior capsular reconstruction, and the factors contributing to the achievement of early clinically significant outcomes. METHODS: Patients who underwent ASCR between March 2015 and September 2020 with complete preoperative and postoperative 6-month, 1-year, and 2-year patient-reported outcome measures (PROMs) were retrospectively analysed. Threshold values for MCID, substantial clinical benefit, and PASS were obtained from the previous literature for the PROMs. The time required to achieve clinically significant outcomes was calculated using Kaplan-Meier analysis. Multivariate Cox regression was performed to evaluate the variables predictive of an earlier or delayed achievement of MCID. RESULTS: Fifty-nine patients with a mean age of 64.5 ± 8.7 years old were included. The time of mean achievement of MCID, substantial clinical benefit, and PASS for VAS was 11.2 ± 0.9, 16.3 ± 1.1, and 16.6 ± 0.9 months, respectively. The time of mean achievement of MCID, substantial clinical benefit, and PASS for ASES was 13.2 ± 1.0, 16.8 ± 1.0, and 18.3 ± 0.9 months, respectively. The time of mean achievement of MCID, substantial clinical benefit, and PASS for the Constant score was 11.6 ± 0.9, 15.1 ± 1.0, and 14.7 ± 0.9 months, respectively. The time of mean achievement of MCID, substantial clinical benefit, and PASS for SANE was 14.4 ± 1.0, 16.1 ± 1.0, and 15.5 ± 0.8 months, respectively. Patients with a higher preoperative VAS score achieved an earlier MCID for VAS (P = 0.014). However, patients with a higher preoperative ASES and SANE scores achieved delayed MCID for ASES and SANE (P = 0.026, and P < 0.001, respectively). CONCLUSION: Most patients achieved MCIDs around 1 year after arthroscopic superior capsular reconstruction. A higher preoperative VAS score favours faster MCID achievement, while higher preoperative ASES and SANE scores contribute to delayed MCID achievement. STUDY DESIGN: Cohort study LEVEL OF EVIDENCE: Level IV.

Radiologically severe osteoarthritis is related to worse clinical outcomes after arthroscopic osteocapsular arthroplasty in primary elbow osteoarthritis at medium-term follow-up: a retrospective cohort study.

HYPOTHESIS: This study aimed to compare the clinical outcomes after arthroscopic osteocapsular arthroplasty (OCA) at medium-term follow-up according to the radiologic severity of primary elbow osteoarthritis (OA) and assess serial changes in clinical outcomes in each group. METHODS: Patients treated from January 2010 to April 2019 with arthroscopic OCA for primary elbow OA with a minimum of 3 years' follow-up were retrospectively assessed regarding range of motion (ROM), visual analog scale (VAS) pain score, and Mayo Elbow Performance Score (MEPS) preoperatively, at short-term follow-up (3-12 months postoperatively), and at medium-term follow-up (≥3 years after surgery). Preoperative computed tomography was performed to evaluate the radiologic severity of OA using the Kwak classification. Clinical outcomes were compared according to the radiologic severity of OA by their absolute values and the number of patients achieving the patient acceptable symptomatic state (PASS). Serial changes in the clinical outcomes in each subgroup were also assessed. RESULTS: Of the 43 patients, 14, 18, and 11 were classified as the stage I, II, and III groups, respectively; the mean follow-up duration was 71.3 ± 28.9 months, and the mean age was 56.5 ± 7.2 years. At medium-term follow-up, the stage I group had a better ROM arc (stage I, 114° ± 14°; stage II, 100° ± 23°; and stage III, 97° ± 20°; P = .067) and VAS pain score (stage I, 0.9 ± 1.3; stage II, 1.8 ± 2.1; and stage III, 2.4 ± 2.1; P = .168) than the stage II and III groups without reaching statistical significance, whereas the stage I group had a significantly better MEPS (stage I, 93.2 ± 7.5; stage II, 84.7 ± 11.9; and stage III, 78.6 ± 15.2; P = .017) than the stage III group. The percentages of patients achieving the PASS for the ROM arc (P = .684) and VAS pain score (P = .398) were comparable between the 3 groups; however, the percentage achieving the PASS for the MEPS was significantly higher in the stage I group than in the stage III group (100.0% vs. 54.5%, P = .016). During serial assessment, all clinical outcomes tended to improve at the short-term follow-up. Compared with the short-term period, the ROM arc tended to decrease at the medium-term follow-up whereas the VAS pain score and MEPS overall did not show significant changes. CONCLUSION: After arthroscopic OCA, the stage I group showed an overall better ROM arc and pain score than the stage II and III groups at medium-term follow-up, whereas the stage I group showed a significantly better MEPS and higher percentage of patients achieving the PASS for the MEPS than the stage III group.

Biomechanical impact of elbow motion in elbow stiffness.

BACKGROUND: A mechanical block in the elbow due to osteophytes in the olecranon fossa is a common clinical symptom for elbow stiffness. PURPOSE/HYPOTHESIS: This study aims to understand the biomechanical characteristics or changes in the stiff elbow in the resting (or neutral) and swing position of the arm using a cadaveric model. The hypotheses included the following: (1) a difference exists in the articular contact pressure of the elbow by comparing the non-stiff and stiff models in in vivo studies; (2) the degree of stiffness would affect the increase of the joint loading of the elbow. STUDY DESIGN: Controlled laboratory study, cadaveric study. METHODS: Eight fresh-frozen specimens from individuals of both sexes were included in the biomechanical study. The specimen was mounted on a custom-designed jig system with gravity-assisted muscle contracture to mimic the elbow in a standing position. The elbow was tested in two conditions (the resting and passive swing). Contact pressure was recorded for three seconds in the resting position, which was the neutral position of the humerus. By dropping the forearm from 90° of the elbow flexion, the passive swing was performed. The specimens were tested sequentially in three stages of stiffness (stage 0, no stiffness; stage 1, 30° of extension limitation; and stage 2, 60° of extension limitation). After data collection was completed in stage 0, a stiff model was sequentially created for each stage. The stiff model of the elbow was created by blocking the olecranon by inserting a 2.0 K-wire into the olecranon fossa horizontally with the intercondylar axis. RESULTS: The mean contact pressures were 279 ± 23, 302 ± 6, and 349 ± 23 kPa in stages 0, 1, and 2, respectively. The increases in the mean contact pressure in stages 2 versus 0 were significant (P < 0.0001). The mean contact pressures were 297 ± 19, 310 ± 14, and 326 ± 13 kPa in stages 0, 1, and 2, respectively. The peak contact pressures were 420 ± 54, 448 ± 84, and 500 ± 67 kPa in stages 0, 1, and 2, respectively. The increases in mean contact pressure in stage 2 versus 0 were significant (P = 0.039). The increases in peak contact pressure in stages 0 versus 2 were significant (P = 0.007). CONCLUSIONS: The elbow bears the load created by gravity and muscle contracture in the resting and swing motion. Moreover, extension limitation of stiff elbow increases the load bearing in the resting position and swing motion. Careful surgical management should be considered for meticulous clearance of bony spur around olecranon fossa to resolve the extension limitation of the elbow.

Return to physical activities after arthroscopic rotator cuff repair: a systematic review and meta-analysis.

BACKGROUND: Rotator cuff tear is one of the most common disorders in orthopedic surgery. When conservative treatment fails, arthroscopic rotator cuff repair has become the most common procedure to achieve a functional shoulder. HYPOTHESIS/PURPOSE: The articles on return to activities following arthroscopic rotator cuff repair have not been collectively analyzed and investigated. We aimed to review systematically and perform a meta-analysis of studies on the return to activities which consist of the return to work, return to sports, and return to daily activities following arthroscopic rotator cuff repair. STUDY DESIGN: Systematic Review and Meta-Analysis. METHODS: Articles regarding return to activities were systematically searched using databases of PubMed, MEDLINE via EBSCO, ScienceDirect, and ProQuest. The review was done according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guideline. The study protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews. Studies with a level of evidence 1-4 that examined the rate of return to activities after arthroscopic rotator cuff repair were included and analyzed. RESULTS: Fifteen studies published between 2005 and 2021 were included, with 1065 patients (644 male and 421 female). The patient populations are workers and athletes. The meta-analysis on the combined effect of a return to activities using the random-effects model was 88.5% (83.8% on return to work, 88.2% on return to sport, and 97.3% on return to daily activities). The mean duration for return to activities is 6.59 months. CONCLUSION: As much as 88.5% of patients were able to return to activities after arthroscopic rotator cuff repair with a mean duration of 6.59 months. Preoperative factors (gender, workload, chronicity, tear size, and cholesterol level) may contribute to the rate and duration of return to activities.

Extracellular Vesicles Delivered by Injectable Collagen Promote Bone-Tendon Interface Healing and Prevent Fatty Degeneration of Rotator Cuff Muscle.

PURPOSE: This study aimed (1) to confirm the maintenance of the extracellular vesicles (EVs) delivered via injectable collagen at the application site, and (2) to evaluate the effect of EVs derived from the human umbilical cord-derived mesenchymal stem cells and loaded in an injectable collagen gel after rotator cuff repair (RCR). METHODS: Rabbits (n = 20) were assigned to normal (N), repair-only (R), and those administered with injectable collagen after repair (RC), and EV-laden injectable collagen after repair (RCE) groups. The EVs isolated by ultra-centrifugation from the human umbilical cord-derived mesenchymal stem cells spent medium were mixed with collagen and administered accordingly. After 12 weeks, the rabbits were sacrificed to evaluate the healing of the bone-to-tendon junction and the fatty degeneration of muscle. Histomorphometric scoring for bone-tendon interface, fatty infiltration (%), and biomechanical tests were performed. Separately, groups of 3 rabbits were assigned to 3 different time points to evaluate maintenance of green fluorescence-labeled EVs with injectable collagen via tracking on the bursal side of the rotator cuff (3 groups: 3 days, 2, and 4 weeks). RESULTS: The EVs delivered by injectable collagen remained until 4 weeks at the bursal side of the cuff tissue. The RCE group showed a significantly greater histomorphometric total score (P < .001, and P = .013, respectively) and significantly lower fatty degeneration than the RC and R groups (P = .001, and P = .013, respectively). The biomechanical tests revealed significant growing trends in load-to-failure and stiffness (P = .002, and P = .013, respectively), in the R, RC, RCE, and N groups. CONCLUSIONS: EVs mounted in injectable collagen remained at the repair site for at least 4 weeks after application. Furthermore, they effectively promote bone-to-tendon healing via collagen maturation in bone-tendon interface and preventing fatty degeneration of rotator muscle after RCR as compared with collagen-only or repair-only groups. CLINICAL RELEVANCE: The combination of collagen with EVs significantly promotes rotator cuff healing demonstrating potential clinical application during partial rotator cuff tear or after RCR.

Patient-specific instrumentation improves the reproducibility of preoperative planning for the positioning of baseplate components with reverse total shoulder arthroplasty: a comparative clinical study in 39 patients.

BACKGROUND: The application of patient-specific instrumentation (PSI) for reverse total shoulder replacement has been rapidly increasing, which could reduce errors in implant positioning. Although PSI theoretically holds promise, evidence of the accuracy and reliability of PSI in shoulder replacement surgery is limited. METHODS: Thirty-nine shoulders that underwent reverse total shoulder arthroplasty were included in this study and categorized into two groups: the conventional (n = 20) and PSI (n = 19) groups. Screw (length and angle) and baseplate (version, inclination, translation, and rotation) positioning were calculated based on postoperative computed tomography images using a three-dimensional measurement tool. The difference between the values of the preoperative target and postoperative measurement was calculated to evaluate the reproducibility of preoperative planning. Screw involvement in the suprascapular and spinoglenoid notches was assessed. Thus, the correlation between the position of the baseplate and the screws was assessed. RESULTS: The mean differences between the planned length and angle (anteroposterior and superoinferior angles) and postoperative measurement in the PSI group were significantly smaller than those in the conventional group. Similarly, the mean difference in baseplate rotation between the planned and postoperative measurements in the PSI group was significantly lower than that in the conventional group (4.5° vs 10.6°; P < .001). The spinoglenoid notch was involved in 10 cases in the conventional group and 2 cases in the PSI group, and this difference was significant (P = .014). Overall, the mean difference between the preoperative and postoperative version, inferior inclination, and rotation values for the baseplate position was significantly correlated with the values for screw position (length and angle). CONCLUSIONS: PSI improves the reproducibility of preoperative planning for baseplate and screw positioning and reduces the risk of neurovascular injury in reverse total shoulder arthroplasty.

Retear bigger than preoperative tear size would lead to treatment failure after rotator cuff repair.

BACKGROUND: This study aimed to (1) define treatment failure using the referred patient acceptable symptomatic state (PASS) values for pain visual analog scale (PVAS), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and Single Assessment Numeric Evaluation (SANE) clinical scores and (2) identify the factors that lead to patient dissatisfaction after arthroscopic rotator cuff repair (ARCR). METHODS: We analyzed the arthroscopic rotator cuff surgery registry data from January 2015 to December 2016. Patients were followed for ≥2 years and categorized as dissatisfied or satisfied based on our own definition of treatment failure at 2 years postoperatively. For defining treatment failure, the referred PASS values for the PVAS, ASES, and SANE scores were used. Patients who failed to attain the PASS value for the PVAS, ASES, or SANE score were categorized into the dissatisfied group. Pre- and postoperative imaging and basic demographic data were compared between groups. Univariable and multivariable logistic regression analyses were performed to identify the factors affecting patient satisfaction at 2 years after rotator cuff repair. RESULTS: Of 117 patients, 30 (25.6%) were defined as the dissatisfied group (mean follow-up period, 37.5 months). Seventeen patients (14.5%) had confirmed retear on follow-up magnetic resonance imaging. In the univariate analysis, sex significantly differed between the groups (female, satisfied vs. dissatisfied groups: 39 [44.8%] vs. 22 [73.3%]; P = .010). Retear alone did not affect patient satisfaction in the univariate analysis (P = .11). Progressed retear size featured a significantly higher risk of patient dissatisfaction (P = .024; odds ratio 6.430, 95% confidence interval 1.270-32.541) in the multivariable analysis using symptom duration, sex, preoperative ASES score, preoperative tear size, retear, and progressed retear size as variables. Moreover, female sex had an increased odds for dissatisfaction (odds ratio 4.646, 95% confidence interval 1.590-13.578; P = .005). CONCLUSION: Two years after ARCR, most patients (74.4%) reported satisfaction with their outcomes. However, satisfaction levels can be altered by female sex or progressed retear size compared with the preoperative state.

Osteosynthesis with autologous dual bone graft for nonunion of midshaft clavicle fractures: clinical and radiological outcomes.

PURPOSE: This study evaluated the clinical and radiological results of plate osteosynthesis with autologous cortical and cancellous bone graft for nonunion of midshaft clavicle fracture. METHODS: A retrospective review was performed for all patients who underwent surgery for midshaft clavicle nonunion at a Level I trauma center. Visual analog scales (VAS) for pain and Quick-DASH (Disabilities of Arm, Shoulder, and Hand) score were assessed. Bone union rate, change in length of affected clavicle, complications, and reoperation were determined. Risk factors were identified to determine the effect on the healing. RESULTS: Thirty-four patients were included for analysis. All patients achieved solid bone union at mean 16 weeks (range 8-36) after surgery. The mean shortening of affected clavicle decreased significantly postoperatively (P < 0.001). There was significant improvement in both pain VAS and Quick-DASH score (P < 0.001). There was no wound complication, infection, or major neurovascular injury. Ten patients (29%) complained of plate irritation and underwent removal of implant without any subsequent adverse event. Multiple regression analysis demonstrated that high-energy trauma and previous surgery were the independent risk factors that significantly delayed time to union (P < 0.05). CONCLUSION: Osteosynthesis with autologous dual bone graft for nonunion of midshaft clavicle produced an excellent union rate with good clinical outcome and minimal complications.

Is reverse total shoulder arthroplasty (rTSA) more advantageous than anatomic TSA (aTSA) for osteoarthritis with intact cuff tendon? A systematic review and meta-analysis.

PURPOSE: We aimed to compare the outcomes and complications of anatomical shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) for primary glenohumeral osteoarthritis with intact cuff tissue. MATERIALS AND METHODS: The MEDLINE, Embase, and Cochrane Library databases were systematically searched for studies published before March 2, 2021 using the PRISMA guidelines. Studies were included if they directly compared aTSA and rTSA for treating primary glenohumeral arthritis. A meta-analysis was performed using six studies that compared radiologic outcomes, functional scores, and range of motion (ROM). All the data were pooled using a random-effects model. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated as dichotomous data, while continuous data were analyzed using mean differences with 95% CIs. RESULTS: Two independent researchers reviewed 1,061 studies. Six studies met the inclusion criteria. The range of motion, especially external rotation, was better for aTSA than for rTSA (MD = - 10.28, 95% CI: - 16.69 to - 3.88, P = 0.002). Functional scores showed no difference between aTSA and rTSA. Glenoid loosening (OR = 0.17, 95% CI: 0.06-0.50, P = 0.001) was more common with aTSA, and scapula notching (OR = 10.63, 95% CI: 1.73-65.27, P = 0.01) with rTSA. In the mid-term follow-up, the overall revision rate showed no difference between aTSA and rTSA, with a pooled OR of 0.33 (95% CI: 0.07-1.57, P = 0.16). CONCLUSION: A better ROM was achieved after aTSA than after rTSA. There was no difference in the revision rate at mid-term follow-up between aTSA and rTSA. Glenoid loosening was more common with aTSA, and scapula notching with rTSA. LEVEL OF EVIDENCE: Level IV, Meta-analysis.