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.

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.

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.

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.

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.

Double-bundle ACL reconstruction versus anatomic single-bundle ACL reconstruction combined with anterolateral ligament reconstruction: a comparative study of clinical outcome.

INTRODUCTION: Recent studies showed increasing evidences of anterolateral ligament (ALL) reconstruction in conjunction with anterior cruciate ligament (ACL) reconstruction that proves to be more superior to the previous double-bundle (DB) ACLR technique especially in improving knee stability in biomechanic studies. However to date, there have been no studies evaluating the functional outcome of DB-ACLR vs single-bundle (SB) with ALL in ACLR. METHODS: A total of 138 patients with ACL deficient knee were enrolled to the study. Double-bundle ACL reconstruction (DB-ACLR) was performed in 75 patients and single-bundle ACL reconstruction with anterolateral ligament reconstruction (SB + ALL) ACLR was performed in 63 patients. Surgical outcomes were compared with The International Knee Documentation Committee Subjective Knee Form (IKDC) and the Kujala score at the 3rd, 6th and 9th month post-operative. RESULTS: The IKDC score in the 3rd and 6th month was superior in the SB + ALL group compared to the DB group. However, this difference was not statistically significant. In the meantime, there were no statistically significant difference between the Kujala Score at the 3rd, 6th, and 9th months consecutively. There were no statistically significant differences in the functional outcomes of DB-ACLR and SB + ALL groups at the 3rd, 6th, and 9th months post-operative period. CONCLUSION: The functional outcome comparison showed non-superiority of SB + ALL group compared to the DB-ACLR group. The patellar pain was less found in DB-ACLR group at 6- and 9-months post-operative period.

The dynamic rotation axis of ulnohumeral joint during active flexion-extension: an in vivo 4-dimensional computed tomography analysis.

BACKGROUND: As the collateral ligament reconstruction becomes more common to perform, the knowledge between the collateral ligament reconstruction and the elbow rotation axis is still ambiguous. The purpose of this study was to investigate the location of the intersections between the elbow rotation axis and medial and lateral aspect of the humerus. METHODS: Four-dimensional computed tomography (4D CT) scan was designed to obtain the images from 8 participants. The instantaneous rotation axis was created according to the trochlea notch of the ulna in the Rapidform XO software. Then the intersections between the instantaneous rotation axis and the medial and lateral aspect of the humerus were identified in the Geomagic Wrap software. Landmark coordinate systems of the distal humerus was created. RESULT: The intersections in the medial aspect of the humerus were mostly located in the superior and posterior quadrant and showed the trend from anterior-superior to posterior-superior with the increment of the elbow flexion. The intersections in the lateral aspect of the humerus were mostly located in the middle half of the anterior quadrant and showed the trend from posterior-inferior to anterior-superior with the increment of the elbow flexion. CONCLUSION: There's no isometric point for medial collateral ligament (MCL) and lateral ulnar collateral ligament (LUCL) reconstruction. The isometric area for MCL reconstruction should be considered at the superior and posterior quadrant of the medial aspect of the humerus. The isometric area for LUCL reconstruction should be considered at the middle half of the anterior quadrant of the lateral aspect of the humerus. TRIAL REGISTRATION: This work was supported by the National Natural Science Foundation of China [ No.81911540488 ] in 07/01/2019.

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.

Forearm Interosseous Ligaments: Anatomical and Histological Analysis of the Proximal, Central, and Distal Bands.

PURPOSE: To characterize and compare the histological structure of the proximal, central, and distal bands of the interosseous membrane (IOM) of the human forearm in fresh-frozen specimens. METHODS: The IOMs from 16 fresh-frozen left forearm specimens were carefully dissected and examined. The footprint areas of the proximal, central, and distal IOM bands were measured in 6 specimens. The histological characteristics of the IOM bands were evaluated using hematoxylin-eosin and Masson trichrome staining protocols in 10 specimens as histological analysis necessitated an intact footprint. The footprint areas of the IOM were measured using an image processing program. The insertion complex was assessed using a light microscope. RESULTS: Histological assessment revealed that the IOM structure demonstrated similarities with ligament structure. The average footprint areas of the proximal, central, and distal bands at the radial site were 11.1 ± 0.8, 180.4 ± 30.4, and 10.7 ± 1.3 mm2, respectively. At the ulnar site, they were 11.0 ± 1.1, 171.8 ± 30.1, and 10.7 ± 1.2 mm2, respectively. The insertion complex of the IOM into the bone comprised 4 layers: (1) interwoven collagen, (2) oblique collagen, (3) mineralized fibrocartilage (tidemark), and (4) lamellar bone. The average tidemark zone thicknesses of the proximal, central, and distal bands were 20.1 ± 6.3, 107.8 ± 22.9, and 20.6 ± 4.7 µm, respectively at the radial site and 12.0 ± 4.5, 85.7 ± 23.2, and 13.5 ± 6.9 µm, respectively at the ulnar site. CONCLUSIONS: In this study, we confirm that the histological characteristics of the IOM are similar to those of ligaments. Compared with the proximal and distal bands, the central band has a greater footprint area and thicker tidemark zone. CLINICAL RELEVANCE: If surgical reconstruction is performed, the size and histological characteristics of the graft should be similar to those of the native ligaments.

Subacromial bursal preservation can enhance rotator cuff tendon regeneration: a comparative rat supraspinatus tendon defect model study.

BACKGROUND: The role of subacromial bursa in rotator cuff surgery is unknown. This study aimed to assess the subacromial bursa's role in the healing of supraspinatus tendon injury in a rat model. METHODS: Twenty-three male Sprague-Dawley rats (9 weeks old; weight, approximately 296 g) were used in this study. Three rats used as biomechanical study controls were killed at 12 weeks of age. A supraspinatus tendon defect was made bilaterally in 20 rats, whereas an additional subacromial bursa sectioning was performed on the left side. Six rats were killed for biomechanical testing and 4 were killed for histologic observation at 3 and 9 weeks, respectively. RESULTS: The regenerated tendon in the bursal preservation group showed significantly superior biomechanical properties in maximum load to failure at 3 and 9 weeks and stiffness at 9 weeks after surgery compared with the bursal removal group. The modified Bonar scale scores showed better regenerated supraspinatus tendons in the bursal preservation group. CONCLUSION: The present study found that the subacromial bursa plays an important role in rotator cuff regeneration in this rat supraspinatus injury model. Extensive bursectomy of the subacromial bursa may not be recommended in rotator cuff repair surgery, though future in vivo human studies are needed to confirm these observations.

The contact area of the radiocapitellar joint under pronation and supination with axial load using a 3-dimensional computed tomography: an in vivo study.

OBJECTIVE: To evaluate the contact area of the radiocapitellar joint with forearm pronation and supination under axial loading. MATERIALS AND METHODS: Six healthy volunteers (2 males and 4 females, mean age: 44.6 years) were included in the study. A computed tomography scan of the extended elbow joints was obtained at 4 positions of forearm: full pronation with or without load and full supination with or without load. Mimics, 3-matic Medical, Geomagic, and Photoshop were used to reconstruct 3-dimensional models. The contact area of the radiocapitellar joint was measured. Shifting of the center of the contact area of the radiocapitellar joint was measured. RESULTS: The axial load added 8.6% and 10.5% contact area to pronation and supination without load, respectively. From pronation without load, the center of contact area significantly shifted 2.4 ± 1.1 mm anteromedially to supination without load and shifted by 1.0 ± 0.5 mm to the center of the radial head compared with the pronation with load. The center of the contact area significantly shifted 2.4 ± 1.5 mm anteromedially from the pronation to the supination under loading. The contact area of the tuberosity anterior in the radial head significantly increased by 14% (without load) and 8% (with load) from pronation to supination. CONCLUSION: Axial loading increases the contact area of the radiocapitellar joint. The center of the contact area of the radiocapitellar joint changed according to loading and shifted to the anterior tuberosity of the radial head from forearm pronation to supination.

Determination of the patient acceptable symptomatic state after osteocapsular arthroplasty for primary elbow osteoarthritis.

BACKGROUND: The study aimed (1) to determine patient acceptable symptomatic state (PASS) values for the pain visual analog scale (PVAS), range-of-motion (ROM) scale difference, Mayo Elbow Performance Score (MEPS), and Self-evaluation Elbow (SEE) following osteocapsular arthroplasty for primary elbow osteoarthritis and (2) to determine factors for achieving the PASS. METHODS: The study analyzed retrospectively collected osteocapsular arthroplasty registry data from January 2010 to April 2019. Fifty patients were evaluated, and anchor questions for deriving PASS values were administered at a 1-year follow-up. PASS values for the PVAS score, ROM difference, MEPS, and SEE score were derived using a sensitivity- and specificity-based approach. Univariate and multivariate logistic regression analyses were performed to determine factors for achieving the PASS. A subgroup comparison analysis based on age was also conducted. RESULTS: The PASS value was 1.0 for the PVAS score, 15° for ROM difference, 75 for the MEPS, and 60 for the SEE score. Older age (≥65 years) showed significantly lower odds ratios for achieving the PASS for the PVAS score (0.888; 95% confidence interval, 0.804-0.981; P = .032) and ROM (0.861; 95% confidence interval, 0.760-0.976; P = .020). CONCLUSION: Reliable PASS values were derived for the PVAS score, ROM difference, MEPS, and SEE score after osteocapsular arthroplasty. The PASS values defined in this study can be implemented as clinically relevant targets in patients undergoing osteocapsular arthroplasty. An analysis of factors that affect clinical symptom improvement showed that older age (≥65 years) was significantly correlated with lower PASS values for the PVAS score and ROM.

The elbow plica: a systematic review of terminology and characteristics.

BACKGROUND: There has been a lack of evidence regarding the structure of the elbow plica, or synovial fold. Inconsistency remains regarding the correct terminology, prevalence, and investigation used to understand this anatomic structure. METHODS: For this systematic review, we searched the PubMed, Ovid-MEDLINE, Cochrane, Google Scholar, and Embase databases using keywords as well as medical subject headings for English-language studies. We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. RESULTS: We included 27 articles in this review. "Plica" was the most commonly used terminology (33%). The prevalence of plicae in asymptomatic and symptomatic patients was 77% and 97%, respectively. Provocative factors were sporting activities (57%), including those performed by professional athletes, and heavy labor (43%). Lateral elbow pain represented the most common symptom (49%). Magnetic resonance imaging was the most commonly used diagnostic modality (64%). On the magnetic resonance imaging scans of symptomatic patients, the most common location of the plica was the posterolateral region (54%) and its thickness was a minimum of 3 mm. In 2 studies that included symptomatic patients, the plica was found to cover more than one-third of the radial head. CONCLUSION: Plicae are prevalent in both asymptomatic and symptomatic patients. Consideration of the pathologies associated with an elbow plica helped identify the following: (1) its thickness is >3 mm and (2) its location is in the posterolateral aspect and/or it covers more than one-third of the radial head quadrant.

Topography of sensory receptors within the human glenohumeral joint capsule.

BACKGROUND AND HYPOTHESES: Sensory receptors in the joint capsule are critical for maintaining joint stability. However, the distribution of sensory receptors in the glenohumeral joint of the shoulder, including mechanoreceptors and free nerve endings, has not been described yet. This study aimed to describe the distributions of different sensory receptor subtypes in the glenohumeral joint capsule. Our hypotheses were as follows: (1) Sensory receptor subtypes would differ in density but follow a similar distribution pattern, and (2) the anterior capsule would have the highest density of sensory receptors. METHODS: Six glenohumeral joint capsules were harvested from the glenoid to the humeral attachment. The capsule was divided into 4 regions of interest (anterior, posterior, superior, and inferior) and analyzed using modified gold chloride stain. Sensory receptors as well as free nerve endings were identified and counted under a light microscope from sections of each region of interest. The density of each sensory receptor subtype was calculated relative to capsule volume. RESULTS: Sensory receptors were distributed in the glenohumeral joint capsule with free nerve endings. The anterior capsule exhibited the highest median density of all 4 sensory receptors examined, followed by the superior, inferior, and posterior capsules. The median densities of these sensory receptor subtypes also significantly differed (P = .007), with type I (Ruffini corpuscles) receptors having the highest density (2.97 U/cm3), followed by type IV (free nerve endings, 2.25 U/cm3), type II (Pacinian corpuscles, 1.40 U/cm3), and type III (Golgi corpuscles, 0.24 U/cm3) receptors. CONCLUSION: Sensory receptor subtypes are differentially expressed in the glenohumeral joint capsule, primarily type I and IV sensory receptors. The expression of sensory receptors was dominant in the anterior capsule, stressing the important role of proprioception feedback for joint stability. The surgical procedure for shoulder instability should consider the topography of sensory receptors to preserve or restore the proprioception of the shoulder joint.

Loosening and revision rates after total shoulder arthroplasty: a systematic review of cemented all-polyethylene glenoid and three modern designs of metal-backed glenoid.

BACKGROUND: Several modern designs of metal-backed glenoids (MBG) have been devised to overcome flaws such as loosening and a high failure rate. This review aimed to compare rates of complications and revision surgeries between cemented polyethylene glenoid (PEG) and three examples of modern MBG designs. METHODS: Literature search was carried out using PubMed, Cochrane Library, EMBASE, and Google Scholar using MeSH terms and natural keywords. A total of 1186 articles were screened. We descriptively analyzed numerical data between the groups and statistically analyzed the categorical data, such as the presence of radiolucent line, loosening, and revision surgery (failure). Articles were divided into three groups based on follow-up duration: < 36-month, 36-72-month, and > 72-month subgroups. RESULTS: This study included 35 articles (3769 shoulders); 25 on cemented PEG and ten on the modern MBG. Mean age was 66.4 (21-93) and 66.5 years (31-88). The mean duration of follow-up was 73.1 (12-211) and 56.1 months (24-100). Overall, the rate of the radiolucent line was 354/1302 (27%) and 47/282 (17%), the loosening rate was 465/3185 (15%) and 22/449 (5%), and the failure rate was 189/3316 (6%) and 11/457 (2%), for PEG and MBG, respectively. The results of < 36-month and 36-72-month subgroups showed lower rates of radiolucency and loosening in the cemented PEG group, but there was no significant difference in failure rate (P = 0.754 and 0.829, respectively). In the > 72-month subgroup, MBG was better in terms of loosening (P < 0.001) and failure rates (P = 0.006). CONCLUSIONS: The modern MBG component, especially TM glenoid, seems to be a promising alternative to cemented PEGs, based on subgroup revision rates according to the follow-up duration and overall results of ROM and clinical scores. All polyethylene glenoids tend to increase loosening and failure over time. Three modern MBG designs seem to have no difference in failure, at least in the < 36-month and 36-72-month subgroups compared to the cemented PEG. More long-term follow-up studies on modern MBG should be ultimately conducted. LEVEL OF EVIDENCE: Level IV, systematic review.

Navigation-assisted anchor insertion in shoulder arthroscopy: a validity study.

BACKGROUND: This study aimed to compare conventional and navigation-assisted arthroscopic rotator cuff repair in terms of anchor screw insertion. METHODS: The surgical performance of five operators while using the conventional and proposed navigation-assisted systems in a phantom surgical model and cadaveric shoulders were compared. The participating operators were divided into two groups, the expert group (n = 3) and the novice group (n = 2). In the phantom model, the experimental tasks included anchor insertion in the rotator cuff footprint and sutures retrieval. A motion analysis camera system was used to track the surgeons' hand movements. The surgical performance metric included the total path length, number of movements, and surgical duration. In cadaveric experiments, the repeatability and reproducibility of the anchor insertion angle were compared among the three experts, and the feasibility of the navigation-assisted anchor insertion was validated. RESULTS: No significant differences in the total path length, number of movements, and time taken were found between the conventional and proposed systems in the phantom model. In cadaveric experiments, however, the clustering of the anchor insertion angle indicated that the proposed system enabled both novice and expert operators to reproducibly insert the anchor with an angle close to the predetermined target angle, resulting in an angle error of < 2° (P = 0.0002). CONCLUSION: The proposed navigation-assisted system improved the surgical performance from a novice level to an expert level. All the experts achieved high repeatability and reproducibility for anchor insertion. The navigation-assisted system may help surgeons, including those who are inexperienced, easily familiarize themselves to of suture anchors insertion in the right direction by providing better guidance for anchor orientation. LEVEL OF EVIDENCE: A retrospective study (level 2).