Supraspinatus Tendon Research Articles

Age and Sex Comparison of the Canine Supraspinatus Tendon Using Quantitative Magnetic Resonance Imaging T2 Mapping.

The normal canine supraspinatus tendon has properties commonly attributed to damage such as core hyperintensity and increased width. Little is published regarding the normal tendon, including how senescent changes and sex differences may affect the appearance. Conventional magnetic resonance imaging (MRI) techniques provide subjective analysis of tendons based on observer assessment of signal intensity and appearance. Quantitative MRI (qMRI) techniques such as T2 mapping provide an objective comparison of collagen orientation with analysis of a decay constant, T2. This study investigates age and sex related changes in the canine supraspinatus tendon using the qMRI technique of T2 mapping. In this study, 34 tendons of clinically sound male and female dogs (0.6-13 years) were imaged using qMRI T2 mapping techniques. Sagittal plane T2 maps of the supraspinatus tendon were depth-normalized, and profiles compared using two separate four-parameter logistic equations describing T2 mapping profiles as sigmoidal curves. Combined parameters evaluated included range of T2 values, curve steepness, vertical curve shift, lower bound of T2, upper bound of T2 and horizontal curve shift. A significant reduction in the most central portion of the supraspinatus tendon was found for every increased year in age (-1.56 ± 0.47 milliseconds [-2.56, -0.56, p = 0.004]). No significant difference in curve parameters was found between sexes. The reduction in T2 with age suggests a senescent change may be anticipated with the canine supraspinatus tendon.

Acromial Morphology and Its Relation to the Glenoid Is Associated with Different Partial Rotator Cuff Tear Patterns

The pathogenesis of subacromial impingement syndrome is controversially discussed. Assuming that bursal sided partial tears of the supraspinatus tendons are rather the result of a direct subacromial impact, the question arises whether there is a morphological risk configuration of the acromion and its spatial relation to the glenoid. Patients who underwent arthroscopic repair of either a partial articular supraspinatus tendon avulsion (PASTA) or bursal-sided supraspinatus tear (BURSA) were retrospectively allocated to two groups. Various previously described and new omometric parameters on standard anteroposterior and axial shoulder radiographs were analyzed. We hypothesized that acromial shape and its spatial relation to the glenoid may predispose to a specific partial supraspinatus tendon tear pattern. The measurements included the critical shoulder angle (CSA), the acromion index (AI), Bigliani acromial type and the new short sclerotic line, acromioclavicular offset angle (ACOA), and AC offset. The ratio length/width of acromion and the medial acromial offset were measured on axial radiographs. A total of 73 patients were allocated to either PASTA (n = 45) or BURSA (n = 28). The short sclerotic line showed a statistically significant difference between PASTA and BURSA (16.2 mm versus 13.1 mm, p = 0.008). The ratio acromial width/length was statistically significant (p = 0.021), with BURSA having slightly greater acromial length (59 vs. 56 mm). The mean acromial offset was 42.9 mm for BURSA vs. 37.7 mm for PASTA (p = 0.021). ACOA and AC offset were both higher for BURSA, without reaching statistical significance. The CSA did not differ significantly between PASTA and BURSA (33.73° vs. 34.56°, p = 0.062). The results revealed an association between a narrow acromial morphology, increased medial offset of the acromion in relation to the glenoid, and the presence of a short sclerotic line in the anteroposterior radiograph in bursal-sided tears of the supraspinatus tendon. Assuming that bursal-sided tears are rather the result of a direct conflict of the tendon with the undersurface of the acromion, this small subgroup of patients presenting with impingement syndrome might benefit from removing a harming acromial spur.

Arthroscopic advancement of the supraspinatus muscle and tendon for posterosuperior massive rotator cuff tears

The tension-free repair of retracted supraspinatus tears with the open muscle and tendon advancement technique first described by Debeyre in 1965 gave satisfactory clinical results. The purpose of this anatomical study was to test the feasibility of an arthroscopic supraspinatus advancement technique. A total of 10 cadaveric shoulders were operated. We assessed the feasibility, measured the slide distance, and recorded the position of the suprascapular nerve (SSN) for each shoulder. Reattachment of the tendon to its native footprint was achieved in all cases. The mean slide distance was 38.8 mm ± 3.6 (33–44). The SSN was released and tension-free in all shoulders. Arthroscopic advancement of the supraspinatus muscle and tendon enables complete rotator cuff repair in irreparable retracted posterosuperior tears and is a noteworthy alternative to the other techniques. Level of Evidence: IV.

Could the Improvement of Supraspinatus Muscle Activity Speed up Shoulder Pain Rehabilitation Outcomes in Wheelchair Basketball Players?

Shoulder pain (SP) is a common clinical complaint among wheelchair basketball (WB) players, since their shoulders are exposed to intense overload and overhead movements. The supraspinatus tendon is the most exposed to WB-related injuries and it is primarily responsible for SP in WB athletes. In these cases, SP rehabilitation remains the main treatment, but there is still a lack of specific protocols which should be customized to WB players' peculiarities and to the supraspinatus muscle activity monitor, and the improvement of rehabilitation outcomes is slow. Thus, the aim of this study was to verify if the improvement of supraspinatus muscle activity, monitored in real time with surface electromyography (sEMG) during the execution of therapeutic exercises, could speed up SP rehabilitation outcomes in WB players. Thirty-three athletes were enrolled. They were divided into two groups. Both groups underwent the same shoulder rehabilitation program, but only the Exercise Plus sEMG Biofeedback Group executed therapeutic exercises while the activity of the supraspinatus muscles was monitored using sEMG. Participants were evaluated at enrollment (T0), at the end of 4 weeks of the rehabilitation program (T1), and 8 weeks after T1 (T2), using the following outcome measures: supraspinatus muscle activity as root mean square (RMS), Wheelchair User's Shoulder Pain Index (WUSPI), shoulder abduction, and external rotation range of motion (ROM). The Exercise Plus sEMG Biofeedback Group improved more and faster for all the outcomes compared to the Exercise Group. The monitoring and improvement of supraspinatus muscle activity seems to be an effective way to speed up SP rehabilitation outcomes in WB players, since it makes the performance of therapeutic exercise more precise and finalized, obtaining better and faster results in terms of recovery of shoulder function.

Sonographic and elastographic findings after arthroscopic rotator cuff repair: a comparison with clinical results.

We assessed the relationship between early postoperative clinical outcomes of arthroscopic rotator cuff repair (ARCR) and observations obtained by postsurgical ultrasound (US) and strain elastography (SE) of repaired supraspinatus tendons (SSTs). This retrospective study included 42 cases in which the patient underwent ARCR followed by postoperative US and SE. The Korean Shoulder Scoring (KSS) system was used to assess preoperative and postoperative conditions. The thickness of the repaired SST and subdeltoid fluid was measured by US. SE scores were classified into four grades (1 to 4) according to elasticity of repaired SST. In addition, SE scores were divided into two groups: soft (SE scores of 1 and 2) and hard (SE scores of 3 and 4). The relationship between clinical outcomes and US parameters and SE scores was determined by KSS. Postoperative SE scores observed by two readers correlated significantly with function (p = 0.021 and p = 0.021, respectively) and muscle strength (p = 0.008 and p = 0.015, respectively). SE scores were significantly correlated with a difference value of muscle strength of KSS scores (p = 0.002 and p = 0.014). In a comparison of hard and soft groups of repaired SSTs, function (p = 0.008 and p = 0.010, respectively) and muscle strength (p = 0.002 and p = 0.014, respectively) in postoperative KSS scores were statistically higher in the hard SE scores than the soft SE scores. The difference value of function (p = 0.021 and p = 0.021,) and muscle strength (p = 0.008 and p = 0.015) of KSS scores was significantly higher in the hard SE scores. Postoperative SE scores of repaired tendons correlated significantly with muscle strength and function after ARCR. Postoperative US images including thickness of repaired tendon and subdeltoid fluid did not correlate with clinical outcome. SE evaluations of repaired SST may provide important information about postoperative muscle strength and function.

High Acromial Slope and Low Acromiohumeral Distance Increase the Risk of Retear of the Supraspinatus Tendon After Repair.

High Acromial Slope and Low Acromiohumeral Distance Increase the Risk of Retear of the Supraspinatus Tendon After Repair.

Investigating The Association Between Supraspinatus Tendon Abnormality, Shoulder Pain and Isokinetic Strength in Elite Swimmers: A Cross-Sectional Study.

Shoulder pain is common among elite swimmers due to the tremendous stress over shoulders during swimming. Supraspinatus muscle is one of the major prime movers and stabilizers of shoulder and is highly susceptible to overloading and tendinopathy. An understanding of the relationship between supraspinatus tendon and pain; and between supraspinatus tendon and strength would assist health care practitioners for developing training regime. The objectives of this study are to evaluate 1) the association between structural abnormality of supraspinatus tendon and shoulder pain and 2) the association between structural abnormality of supraspinatus tendon and shoulder strength. We hypothesized that structural abnormality of supraspinatus tendons positively associated with shoulder pain and negatively associated with shoulder muscle strength among elite swimmers. 44 elite swimmers were recruited from the Hong Kong China Swimming Association. Supraspinatus tendon condition was evaluated using diagnostic ultrasound imaging and shoulder internal and external rotation strength was evaluated by the isokinetic dynamometer. Pearson's R was used to study the correlation between shoulder pain and supraspinatus tendon condition and to evaluate the association between isokinetic strength of shoulders and supraspinatus tendon condition. 82 shoulders had supraspinatus tendinopathy or tendon tear (93.18%). However, there was no statistically significant association between structural abnormality of supraspinatus tendon and shoulder pain. The results showed that there was no association between supraspinatus tendon abnormality and shoulder pain and there was a significant correlation between left maximal supraspinatus tendon thickness (LMSTT) and left external rotation/ concentric (LER/Con) and left external rotation/ eccentric (LER/Ecc) shoulder strength (p < 0.05) while internal rotation/ external rotation (IR/ER) ratio can also be a significant predicator on LMSTT >6mm (R2 = 0.462, F = 7.016, df = 1, p = 0.038). Structural change of supraspinatus tendon was not associated with shoulder pain, but could be a predictor on MSTT >6mm in elite swimmers.

Arthroscopic repair of rotator cuff injury with bioabsorbable suture anchor vs. all-suture anchor: a non-inferiority study

BackgroundCompare all-suture anchors to traditional anchors through clinical and radiological evaluation at pre-established end-points.Materials and methodsWe performed a two-arms non-inferiority study on all-suture anchor (2.3 iconix™, Stryker) device with respect to traditional anchor (5.5 healix Advance™ BR, Depuy/Mitek) device under unpaired samples with size equal to 30 patients per group, all suffering from supraspinatus tendon rupture. We administrated DASH (Disabilities of the Arm, Shoulder and Hand); constant; and SST (Simple Shoulder Test) questionnaires in pre-operative, 3 ± 1 months post-intervention and 8 ± 1 months post-intervention. Questionnaires scores were the primary outcome. We also evaluated RMI at 3 and at 8 months after surgery to assess the presence of oedema or any loosening of the implant.ResultsAll-suture anchor approach has been proven to have non-inferior performances with respect to traditional anchor approach, according to questionnaires scores at the 3-month endpoint. We observed 26 patients with oedema by MRI (18 in control group, 6 in experimental group). In the 8-month endpoint we found persistent edema in 12 patients (all treated with healix), 2 had mobilitazions (healix), 10 had partial retears (8 healix, 2 iconix) and 1 implant failure (healix).ConclusionsAll suture devices have clinical and functional results comparable to traditional devices, while they tend to give fewer complications in terms of bone edema, loosening and retear rate. The effectiveness of all-suture devices should be further investigated in rotator cuff suture arthroscopic revision surgery, given the advantages they offer.

Combination of autologous osteochondral and periosteum transplantation effectively promotes fibrocartilage regeneration at the tendon-bone junction of the rotator cuff in rabbits.

Rotator cuff tendon-bone healing often leads to scarring and low biomechanical strength, resulting in a tendency to re-tear. This study examined whether combining autologous osteochondral transplantation and periosteum transplantation increases fibrocartilage transition zone regeneration and improves biomechanical fixation. A total of 48 New Zealand white rabbits were divided into the periosteum, autologous osteochondral, combination of autologous osteochondral and periosteum, and control groups. The supraspinatus tendon was cut from the greater tuberosity and repaired by different transplants. A total of 12 rabbits were used for histological examination (haematoxylin and eosin staining, Masson's staining and Safranin-O staining) at 4, 8 and 12weeks after the repair, and 36 rabbits were used for biomechanical tests (maximal failure load and stiffness). At 4weeks following the operation, each group had a large tendon-bone gap with a small number of disordered collagen fibres. At 8weeks, the tendon-bone gap was smaller than that before the operation, and the tendon-bone gap in each experimental group was smaller with neater and denser collagen fibres and chondrocytes than in the control group, with the osteochondral combined periosteum group having the best results. At 12weeks, the typical tendon-bone transitional structure was observed in the osteochondral combined periosteum group, and more collagen fibres and chondrocytes were generated in each group. The osteochondral combined periosteum group had the largest staining area and the largest amount of cartilage. The maximum tensile strength and stiffness of each group increased over time. There was no significant difference in each group's maximum tensile strength and stiffness at 4weeks after the operation. However, the maximum tensile strength and stiffness of the osteochondral combined periosteum group at 8 and 12weeks after operation were significantly higher than those of other groups (P < 0.05). Histological and biomechanical results show that autologous osteochondral transplantation combined with periosteum transplantation can effectively promote the regeneration of fibrous cartilage in the tendon-bone junction of the rotator cuff. It is concluded that this technique is a new treatment method to promote tendon-bone healing in the rotator cuff.

Combination of Local Anesthetics and Corticosteroids as Pain Management in Supraspinatus Tendinitis: A Case Report

Introduction: This study aimed to report the treatment of tendinitis in combination with local anesthetics and corticosteroids.&#x0D; Case presentation: A man, 34 years old, came to the hospital with complaints of pain in the right shoulder. This pain is felt especially when moving the right shoulder, and the patient also cannot raise his right hand. Pain when moving the right arm appeared after falling off a motorbike about 1 month ago. The intensity of pain has been getting higher for the last 14 days, especially when going to bed, so the patient complains of difficulty sleeping. The patient has been treated at the public health center for a month and has received pain relievers. Physical examination showed vital signs within normal limits and pain intensity of 8/10 based on the visual analogue scale. Examination of the extremity shows the abduction of pain starting at 60°-70° on activity and no pain on passive movement. In the special tests, the Neer test is positive, the Hawkin test is positive, and the Empty Can test is positive. The patient was diagnosed with supraspinatus tendinitis. The treatment for this patient is supraspinatus tendon injection. The anesthetic agent used was 2% lidocaine combined with 20 mg triamcinolone corticosteroids. This procedure is performed under ultrasound guidance for precise injection sites. Evaluation after the action found no side effects. After 1 month of action, the patient felt that the pain was greatly reduced (1/10) and the joint movement was not limited.&#x0D; Conclusion: The use of a combination of triamcinolone and lidocaine is beneficial in reducing pain in cases of supraspinatus tendinitis.

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

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. Fifty-two male Sprague-Dawley rats (10weeks old; mean weight, 380g) 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 3days, 1week, and 4weeks after surgery. At 4weeks, four rats from each group were killed for biomechanical test, and three rats from SSG were used for histological evaluation. Absorbable suture knots on the tendon completely degraded at 4weeks. However, nonabsorbable suture knots remained intact between the tendon and articular side. ASG showed a stronger inflammatory reaction at 3days and 1week, but a weaker reaction at 4weeks as confirmed by gross observation and Western blot. Besides, ASG showed superior biomechanical properties in terms of maximum load to failure and stiffness at 4weeks. Modified Bonar score revealed superior maturity for tissue healing in ASG to that in NSG at 4weeks. Furthermore, inferior bone-to-tendon interface and weakest link formation were observed in NSG on histologic images. Absorbable suture knots on the tendon contributed to better mechanical properties compared with the nonabsorbable one after rotator cuff repair.

Effect of shoulder immobilization position and activities of daily living on the stiffness of the repaired supraspinatus tendon

BackgroundAlthough tension on the supraspinatus tendon may be increased by wearing an abduction brace in an improper position or activities of daily living with the operated arm in the brace, the amount of tension has not been objectively evaluated. MethodsEighteen patients who underwent arthroscopic rotator cuff repair were enrolled. The stiffness of the repaired supraspinatus tendon was measured with ultrasound elastography to estimate the tension on the repaired tendon. Measurements were performed in 5 immobilization positions (0°, 30°, and 45° of arm elevation in the scapular plane; 30° of arm elevation in the scapular plane+60° (horizontal adduction) and −60° (horizontal abduction)) and 3 static positions simulating drinking, brushing teeth, and dressing. FindingsStiffness at 30° of scapular plane elevation was lower than 0° of scapular plane elevation (P = 0.034), 30° of elevation in the scapular plane+60° (P < 0.001), and −60° (P < 0.001). There was no significant difference in the stiffness between 30° and 45° of scapular plane elevation (P = 1.000). The stiffness was the greatest at 30° of elevation in the scapular plane−60° among the 5 immobilization positions. The stiffnesses at drinking and brushing teeth were greater than 30° of scapular plane elevation (P < 0.001). InterpretationImmobilization with the arm ≥30° of elevation in the scapular plane may be an optimal position for minimizing stiffness or tension on the repaired tendon. Drinking and brushing teeth may need to be performed using the non-operated arm to protect the repaired tendon.

Anatomical and Interpositional Bursa Preservation Showed Similar Improved Tendon to Bone Healing Compared With the Bursa Removal in a Rat Rotator Cuff Tear Model

To compare the effects of anatomical preservation (AP) and interpositional preservation (IP) of subacromial bursa tissue on tendon-to-bone healing in a rat model of rotator cuff tear. In this study, 48 male Sprague-Dawley rats (average weight 283 g) underwent bilateral supraspinatus tendons severed by sharp incision and repaired immediately. The subacromial bursa tissues were completely removed in 16 rats, who served as the control (CON) group. The other 32 rats were randomly divided into 2 groups AP and IP between tendon and bone. Eight rats of each group were sacrificed for bilateral shoulders at 3 and 9 weeks after the operation, including 5 rats for biomechanical tests and 3 for histologic analysis. No significant differences in terms of biomechanical properties were observed among the groups 3 weeks after surgery. At 9 weeks, the maximum load and stiffness of the AP (32.95 ± 6.33 N, P= .029; 12.49 ± 3.17 N/mm, P < .001; respectively) and IP (33.58 ± 8.47 N, P= .015; 11.63 ± 2.84 N/mm, P= .010, respectively) groups were significantly superior to that of the CON group (26.59 ± 4.47 N; 8.42 ± 2.33 N/mm, respectively). More organized collagen and more mature tendon insertion were observed in AP and IP groups at the interface at 9 weeks, which means better tendon-to-bone healing compared with the CON group. The subacromial bursa plays a positive role in tendon-bone healing. Either anatomical preservation or interpositional preservation between tendon and bone can similarly facilitate the process of healing. Considering the additional surgical time and surgical manipulation, preserving the subacromial bursa at the anatomical position seems to be a better way to promote rotator cuff healing.

Inter- and intra-observer agreement in arthroscopic assessment of the long head of the biceps

IntroductionLong head of the biceps (LHB) pathology is frequent but can be difficult to diagnose. Arthroscopy is the current diagnostic gold-standard. The aim of the present study was to assess inter- and intra-observer agreement in arthroscopic analysis of the LHB. HypothesisAgreement in arthroscopic analysis of the LHB is good in the particular case of small rotator cuff tears. Material and methodsThis prospective study included 49 patients operated on between November 1 and November 30, 2017. Seven surgeons were asked to record videos of arthroscopic LHB analysis for Patte-1 small supraspinatus tendon tears. One junior and 2 senior surgeons analyzed the videos independently, studying macroscopic intrinsic and extrinsic LHB aspect. Inter-observer agreement, and intra-observer agreement for the junior surgeon, were analyzed. ResultsInter-observer agreement between the surgeons and intra-observer agreement for the junior surgeon were slight in describing the pathologic aspect of the LHB: respectively, κ=0.254, p<0.038; and κ=0.319, p<0.0019. DiscussionIsolated arthroscopic LHB assessment without clinical or paraclinical input or precise surgical exploration protocol showed slight inter-observer agreement. Analysis and interpretation of LHB aspect should in practice be based on combined clinical, paraclinical and arthroscopic data. Level of evidenceIII.

Enhanced healing outcomes in MRL/MpJ mouse tissues conserved in insertion site following surgical repair.

Surgical repair of supraspinatus tendons (SSTs) has a high failure rate at the insertion site. A significant hurdle to therapeutic development is that effective intrinsic healing mechanisms are unknown. The MRL/MpJ (MRL) mouse exhibits tissue-specific enhanced healing; however, these tissues exhibit disparate properties from the complex SST. The extent of SST healing in the complex environment of the rotator cuff is unknown. We hypothesized that MRL mice would exhibit enhanced restoration of the structurally complex insertion site, resulting in functional improvements. B6 and MRL mice underwent SST detachment and immediate surgical repair. Mice were analyzed for gait assessment after either 2 or 6 weeks and were then killed humanely for immunohistologic analysis. MRL SSTs demonstrated enhanced recovery of zonal architecture and bone structure compared with B6 SSTs. MRL SSTs exhibited decreased levels of type III collagen at 2 weeks and increased levels of type I procollagen at 6 weeks compared with B6 SSTs. MRL mice experienced initial gait deficits at 2 weeks that had recovered by 6 weeks. The temporal balance of collagen in MRL mice suggests recovery toward naive composition. Initial gait deficits in MRL mice may provide a protective loading environment that is ultimately beneficial. The mechanisms of enhanced healing observed previously in MRL mice may be conserved in the complex SST, providing a platform to interrogate specific aspects of improved healing.

Review of human supraspinatus tendon mechanics. Part I: fatigue damage accumulation and failure.

Repetitive stress injuries to the rotator cuff, and particularly the supraspinatus tendon (SST), are highly prevalent and debilitating. These injuries typically occur through the application of cyclic load below the threshold necessary to cause acute tears, leading to accumulation of incremental damage that exceeds the body's ability to heal, resulting in decreased mechanical strength and increased risk of frank rupture at lower loads. Consistent progression of fatigue damage across multiple model systems suggests a generalized tendon response to overuse. This finding may allow for interventions before gross injury of the SST occurs. Further research into the human SST response to fatigue loading is necessary to characterize the fatigue life of the tendon, which will help determine the frequency, duration, and magnitude of load spectra the SST may experience before injury. Future studies may allow invivo SST strain analysis during specific activities, generation of a human SST stress-cycle curve, and characterization of damage and repair related to repetitive tasks.

Review of human supraspinatus tendon mechanics. Part II: tendon healing response and characterization of tendon health.

Overuse injuries of the rotator cuff, particularly of the supraspinatus tendon (SST), are highly prevalent and debilitating in work, sport, and daily activities. Despite the clinical significance of these injuries, there remains a large degree of uncertainty regarding the pathophysiology of injury, optimal methods of nonoperative and operative repair, and how to adequately assess tendon injury and healing. The tendon response to fatigue damage resulting from overuse is different from that of acute rupture and results in either an adaptive (healing) or a maladaptive (degenerative) response. Factors associated with the degenerative response include increasing age, smoking, hypercholesterolemia, biological sex (variable by tendon), diabetes mellitus, and excessive load post fatigue damage. After injury, the average healing rate of tendon is approximately 1% per day and may be significantly influenced by biologic sex (females have lower collagen synthesis rates) and excessive load after damage. Although magnetic resonance imaging (MRI) is considered the gold standard in assessing acute tears as well as tendinopathic change in the SST, ultrasonography has proven to be a valuable tool to measure tendinopathic change in real time. Ultrasonography can determine multiple mechanical and structural parameters of the SST that are altered in fatigue loading. Thus, ultrasonography may be utilized to understand how these parameters change in response to SST overuse, and may aid in determining the activity level that places the SST at greater risk of rupture.

Correlación entre la incidencia de lesión del manguito rotador en luxación glenohumeral anterior traumática y el hombro contralateral

IntroductionAnterior glenohumeral dislocation in patients older than 60 years is related to rotator cuff lesion because of its pre-existing degenerative condition. However, in this age group, the scientific evidence fails to elucidate whether rotator cuff lesions are the cause or consequence of recurrent shoulder instability. The objective of this paper is to describe the prevalence of rotator cuff injuries in a series of consecutive shoulders in patients older than 60 years who suffered a first episode of traumatic glenohumeral dislocation, and its correlation with rotator cuff injuries in both shoulders. MethodsRetrospectively, 35 patients over 60 years of age who had a first episode of unilateral traumatic anterior glenohumeral dislocation and who had MRI of both shoulders were studied, evaluating both shoulders with MRI to determine the structural damage correlation of the rotator cuff and long head of the biceps between them. ResultsWhen assessing the existence of partial or complete injury to the supraspinatus and infraspinatus tendons, the concordance on the affected and healthy sides, we have shown concordant results on both sides in 88.6 and 85.7%, respectively. The Kappa concordance coefficient was 0.72 for supraspinatus and infraspinatus tendons tear. Of the total of 35 cases evaluated, 8 (22.8%) presented at least some alteration in the tendon of the long head of the biceps on the affected side and only one (2.9%) on the healthy side, where the Kappa coefficient of concordance was 0.18. Of the 35 cases evaluated, 9 (25.7%) presented at least some retraction in the tendon of the subscapularis muscle on the affected side, while no participant showed signs of retraction in the tendon of this muscle on the healthy side. ConclusionsOur study has found a high correlation of the presence of a postero-superior rotator cuff injury after presenting a glenohumeral dislocation between the shoulder that has suffered the event and the presumably healthy contralateral shoulder. Nevertheless, we have not found this same correlation with subscapularis tendon injury and medial biceps dislocation.

Comparison of the spread pattern of medial-to-lateral and lateral-to-medial rotator interval injections: A cadaveric study

ObjectiveRotator interval (RI) corticosteroid injections are used to alleviate pain associated with adhesive capsulitis, though the pattern of injectate spread remains unclear. The purpose of this anatomical study was to assess the staining patterns of intra-articular, intracapsular/extrasynovial, and pericapsular structures of the glenohumeral joint following medial-to-lateral and lateral-to-medial RI injections. DesignTen cadaveric specimens were injected with a methylene blue dye injectate: five using a medial-to-lateral RI injection technique and five using a lateral-to-medial RI injection technique. Serial dissection was performed to assess the staining of intra-articular, intracapsular/extrasynovial, and pericapsular structures. The frequency of capture and degree of staining were compared between injection groups. ResultsThe lateral-to-medial injection resulted in the capture of all intra-articular; intracapsular/extrasynovial; and pericapsular structures, whereas the medial-to-lateral injection did not consistently stain all structures. Intracapsular/extrasynovial structures (superior glenohumeral ligament and the long head of biceps tendon) were more darkly stained in the lateral-to-medial group, and pericapsular structures (supraspinatus tendon and coracohumeral ligament) were more darkly stained in the medial-to-lateral group. ConclusionThe frequency of capture and degree of staining of intra-articular, intracapsular/extrasynovial, and pericapsular structures of the glenohumeral joint differed between medial-to-lateral and lateral-to-medial RI injection techniques, which may influence outcomes in pain management for adhesive capsulitis.

Evolution of functional tissue engineering for tendon and ligament repair.

This review paper is motivated by a Back-to-Basics presentation given by the author at the 2022 Orthopaedic Research Societymeeting in Tampa, Florida. I was tasked with providing a brief history of research leading up to the introduction of functional tissue engineering (FTE) for tendon and ligament repair. Beginning in the 1970s, this timeline focused on two common orthopedic soft tissue problems, anterior cruciate ligament ruptures in the knee and supraspinatus tendon injuries in the shoulder. Historic changes in the field over the next 5decades revealed a transformation from a focus more on mechanics (called "bioMECHANICS") on a larger (tissue) scale to a more recent focus on biology (called "mechanoBIOLOGY") on a smaller (cellular and molecular) scale. Early studies by surgeons and engineers revealed the importance of testing conditions for ligaments and tendons (e.g., high strain rates while avoiding subject disuse and immobility) and the need to measure in vivo forces in these tissues. But any true tissue engineering and regeneration in these early decades was limited more to the use of auto-, allo- and xenografts than actual generation of stimulated cell-scaffold constructs in culture. It was only after the discovery of tissue engineering in 1988 and the recognition of frequent rotator cuff injuries in the early 1990s, that biologists joined surgeons and engineers to discover mechanical and biological testing criteria for FTE. This review emphasizes the need for broader and more inclusive collaborations by surgeons, biologists and engineers in the short term with involvement of those in biomaterials, manufacturing, and regulation of new products in the longer term.