Rotator Cuff Function Research Articles

Muscle Architecture Properties of the Deep Region of the Supraspinatus: A Cadaveric Study.

The supraspinatus is most frequently involved in rotator cuff tears, a common orthopaedic condition. However, the architecture of this muscle has been described only for the superficial, anterior, and posterior regions. To determine the muscle architecture of the deep supraspinatus. Descriptive laboratory study. Muscle architecture measurements were collected from 25 cadaveric supraspinatus specimens (13 intact [without tendon tears], 3 with partial-thickness tears, 9 with full-thickness tears). The muscle was divided into deep, superficial anterior, and superficial posterior regions. Pennation angle, raw and normalized fiber length, and sarcomere length and number were compared using repeated-measures analyses of variance. First, mean architecture measurements were compared between regions using only the intact specimens (n = 13). The deep region had a lower mean pennation angle (3.3° ± 1.0°) compared with the posterior region (11.0° ± 3.9°; P < .0001), which in turn had a significantly higher pennation angle compared with the anterior region (7.6 ± 2.6°; P = .0005). Normalized fiber lengths in the deep region were 21.1% (P = .0052) and 34.5% (P < .0001) shorter than the posterior and anterior normalized fiber lengths, respectively. Sarcomere lengths in the deep region were longer (3.4 ± 0.2 μm) compared with the posterior (3.1 ± 0.2 μm; P = .0012) and anterior (3.2 ± 0.2 μm; P = .0390) regions. Sarcomere numbers also decreased in the deep region by 21.2% (P = .0056) and 34.2% (P < .0001) compared with the posterior and anterior regions, respectively. The deep supraspinatus had significantly lower pennation angles, shorter fiber lengths, and fewer but longer sarcomeres in series compared with other subregions within the muscle. These structural differences suggest a functionally unique "submuscle" within the supraspinatus. Understanding the architecture of the supraspinatus muscle can provide insight into muscle function in health and disease. Specifically, this deep submuscle may play a different role in rotator cuff function than the rest of the muscle.

Reverse Total Shoulder Arthroplasty in the Setting of an Intramuscular Lipoma With Extension Into the Glenoid: A Case Report.

Glenoid bone loss from an infiltrating intramuscular lipoma causing erosive changes is a rare occurrence. A 71-year-old woman with symptomatic rotator cuff arthropathy in the setting of an intramuscular infiltrating lipoma and secondary glenoid bone loss was treated with single-stage tumor excision and reverse total shoulder arthroplasty (rTSA) using an injectable, hard self-setting calcium phosphate as structural bone graft substitute. The patient demonstrated excellent clinical and radiographic outcomes at 2-year follow-up. Infiltrating lipomas resulting in functional rotator cuff arthropathy and erosive osseous glenoid changes are exceedingly rare, yet significant glenoid bony defects present a challenge in the setting of shoulder arthroplasty. This report describes the use of structural bone graft substitute for the management of a glenoid bone defect from a rare case of an intramuscular infiltrating lipoma, while maintaining excellent improvement in functional outcomes and pain after rTSA.

Three-dimensional architecture and moment arms of human rotator cuff muscles invivo: Interindividual, intermuscular, and intramuscular variations.

The human rotator cuff consists of four muscles, each with a complex, multipennate architecture. Despite the functional and clinical importance, the architecture of the human rotator cuff has yet to be clearly described in humans invivo. The purpose of this study was to investigate the intramuscular, intermuscular, and interindividual variations in architecture and moment arms of the human rotator cuff. Muscle volumes, fascicle lengths, physiological cross-sectional areas (PCSAs), pennation angles, and moment arms of all four rotator cuff muscles were measured from mDixon and diffusion tensor imaging (DTI) scans of the right shoulders of 20 young adults. In accordance with the most detailed dissections available to date, we found substantial intramuscular variation in fascicle length (coefficients of variation (CVs) ranged from 26% to 40%) and pennation angles (CVs ranged from 56% to 62%) in all rotator cuff muscles. We also found substantial intermuscular and interindividual variations in muscle volumes, but relatively consistent mean fascicle lengths, pennation angles, and moment arms (CVs for all ≤17%). Moreover, when expressed as a proportion of total rotator cuff muscle volume, the volumes of individual rotator cuff muscles were highly consistent between individuals and sexes (CVs ≤16%), suggesting that rotator cuff muscle volumes scale uniformly, at least in a younger population without musculoskeletal problems. Together, these data indicate limited interindividual and intermuscular variability in architecture, which may simplify scaling routines for musculoskeletal models. However, the substantial intramuscular variation in architecture questions the validity of previously reported mean architectural parameters to adequately describe rotator cuff function.

Preoperative handgrip strength can predict early postoperative shoulder function in patients undergoing arthroscopic rotator cuff repair

BackgroundRotator cuff tears (RCTs) are a common musculoskeletal disorder, and arthroscopic rotator cuff repair (ARCR) is widely performed for tendon repair. Handgrip strength correlates with rotator cuff function; however, whether preoperative grip strength can predict functional outcomes in patients undergoing ARCR remains unknown. This study aimed to investigate the correlation between preoperative grip strength and postoperative shoulder function following ARCR.MethodsA total of 52 patients with full-thickness repairable RCTs were prospectively enrolled. Baseline parameters, namely patient characteristics and intraoperative findings, were included for analysis. Postoperative shoulder functional outcomes were assessed using the Quick Disabilities of the Arm, Shoulder, and Hand (QDASH) questionnaire and Constant–Murley scores (CMSs). Patients were followed up and evaluated at three and six months after ARCR. The effects of baseline parameters on postoperative outcomes were measured using generalized estimating equations.ResultsAt three and six months postoperatively, all clinical outcomes evaluated exhibited significant improvement from baseline following ARCR. Within 6 months postoperatively, higher preoperative grip strength was significantly correlated with higher CMSs (β = 0.470, p = 0.022), whereas increased numbers of total suture anchors were significantly correlated with decreased CMSs (β = − 4.361, p = 0.03). Higher body mass index was significantly correlated with higher postoperative QDASH scores (β = 1.561, p = 0.03) during follow-up.ConclusionsHigher baseline grip strength predicts more favorable postoperative shoulder function following ARCR. A preoperative grip strength test in orthopedic clinics may serve as a predictor for postoperative shoulder functional recovery in patients undergoing ARCR.

Fracture vs. standard stem for proximal humerus fractures using reverse total shoulder arthroplasty

BackgroundReverse total shoulder arthroplasty (rTSA) and hemiarthroplasty are recognized treatment options for significantly displaced proximal humerus fractures. Repair of the tuberosities and preservation of rotator cuff function is a principle of treatment to enhance function and prevent instability. Humeral fracture stems were developed to improve tuberosity union with hemiarthroplasty, and similarly fracture stems are used with rTSA with promising results. However, there are conflicting studies on the use of fracture stems in improving outcomes in rTSA for proximal humerus fracture. The purpose of this study is to determine the clinical and radiographic outcomes, complication and revision rates, and patient satisfaction for fracture vs. standard stems for acute proximal humerus fracture treated with rTSA. MethodsA prospective multi-institutional institutional review board approved registry with a minimum two-year follow-up was queried and identified 231 patients that underwent rTSA for acute proximal humerus fracture, 187 of which received a fracture stem and 44 that received a standard stem. Patients were excluded if there was a previous fracture repair, malunion, or nonunion. Patient demographics, clinical and radiographic outcomes, complications, revision surgery, and patient reported outcome measures were collected preoperatively and at latest follow-up postoperatively. ResultsThe mean follow-up was 48 ± 24 and 54 ± 34 months, mean age was 74 ± 7.9 and 72 ± 8.6 years, and mean body mass index was 28 ± 6.1 and 30 ± 5.3 kg/m2 for fracture and standard stems, respectively. Both fracture and standard stem groups showed significant improvements in patient reported clinical outcomes preoperative to postoperatively. Postoperatively, patients with fracture and standard stems had comparable abduction, forward elevation, internal rotation, external rotation, Visual Analog Scale pain, Global Shoulder Function scale, Simple Shoulder Test scale, American Shoulder and Elbow Surgeons scale, University of California Los Angeles Shoulder score, and Shoulder Arthroplasty Smart score. Patient satisfaction was high and did not differ between the two groups. Similar rates of humeral radiolucent lines, scapular notching, complications, and revision rates occurred between the fracture vs. standard stem groups. ConclusionThere were no significant differences in postoperative clinical outcomes, radiographic outcomes, complication rate, revision rate, and patient satisfaction between the fracture and standard stem groups for the treatment of acute proximal humerus fracture using rTSA. Both stems significantly improved clinical outcomes postoperatively. Either a fracture or standard stem may be used to achieve improved clinical outcomes for acute proximal humerus fracture using rTSA.

Evaluation of the Relationship between Acromiohumeral Distance and Supraspinatus Tendon Thickness Measured by Ultrasonography and Rotator Cuff Pathologies, Pain, and Function.

In this study, we aimed to evaluate acromiohumeral distance (AHD) and supraspinatus tendon (ST) thickness measurements and their relationship with pain and function in ST pathologies. The study included 111 patients and 25 healthy controls (HC). Patients were divided into 3 groups according to their diagnosis: non-tear tendinopathy (NTT), partial thickness tear (PTT), and full thickness tear (FTT). The AHD and ST thickness of the participants were measured with ultrasound. The pain and functional status of the patients were evaluated with the Numeric Rating Scale (NRS), The QuickDASH shortened version of the DASH Outcome Measure - Disabilities of the Arm Shoulder and Hand (QDASH), and Simple Shoulder Test (SST). The AHD value was significantly higher in the NTT group (p=0.000). The AHD value was significantly lower in the FTT group (p=0.000). ST thickness value was significantly lower in the PTT group compared to the NTT group (p=0.000). There was a positive correlation between ST thickness and BMI (r=0.553,p<0.01). There was a negative correlation between ST thickness and SST and a positive correlation between ST thickness (r=-0.223,p<0.05) and QDASH (r=0.276,p<0.05). We found that AHD and SST thicknesses significantly differed in the NTT, PTT, FTT, and HC groups. This difference may be important for diagnosis. In addition, the effect of obesity on ST thickness and the relationship between ST thickness and functional scores may be considered. Weight control may be effective at this point. acromiohumeral distance, supraspinatus tendon thickness, ultrasound.

Exploring Recent Advancements in Rotator Cuff Injury Rehabilitation: A Narrative Review

Rotator cuff injuries are prevalent musculoskeletal injuries that may impair quality of life and function. This narrative review covers current rotator cuff injury rehabilitation breakthroughs and provides insights into evidence-based techniques that improve patient outcomes. Recent advances in evaluation and rehabilitation are the topic of this narrative review. It covers the newest diagnostic techniques and imaging modalities for better diagnosis and patient stratification. It also examines how wearable gadgets and tele rehabilitation might improve recovery. Recent exercise prescription and progression advances include eccentric training, isometric movements, and neuromuscular re-education for rotator cuff repair and function. It emphasises patient-specific rehabilitation procedures and the growing significance of regenerative treatments and biologics in rotator cuff injury treatment. This evaluation also stresses patient education and collaborative decision-making for rehabilitation success. Managing rotator cuff injuries psychologically involves treating pain, fear avoidance, and psychosocial concerns. In conclusion, this narrative review summarises the latest rotator cuff injury rehabilitation techniques and modalities. Rotator cuff injury patients may benefit from these advances in outcomes, recurrence rates, and quality of life. This narrative review helps physicians, researchers, and healthcare workers treating rotator cuff injuries keep current.

Arthroscopic treatment of massive rotator cuff tears involving subscapularis

Introduction. Massive rotator cuff tears represent a major challenge in shoulder surgery. Contemporary arthroscopic techniques allow for repair in majority of cases. In the setting of a massive rotator cuff tear, engagement of subscapularis plays a significant role in function deterioration and is a risk factor for pseudoparalysis.&#x0D; Materials and methods. We present our experience and clinical results with arthroscopic repair of massive rotator cuff tears engaging subscapularis in 32 patients, followed for 12,5 months.&#x0D; Results. Complete repair was performed in 25 (78.1%) and partial repair in 7 (21,9%) of the cases with significant improvement in active forward flexion and good to excellent functional result in 68,8%, according to Constant score. Acute pseudoparalysis was successfully reversed in 8 out of 9 cases (88,8%). Transient neurologic complication was observed in 1 case (3%).&#x0D; Conclusion. Subscapularis plays an important role in massive rotator cuff tears and should always be repaired. Arthroscopic repair of massive rotator cuff tears engaging subscapularis is safe and efficient with good clinical results during one year follow up. While complete repair of all torn tendons with secure reattachment to the tuberosities is the preferred surgical treatment, repair of subscapularis and lower portion of infraspinatus is crucial for normal rotator cuff function. Careful patient selection and individually tailored surgery is important for successful treatment.

Reconstruction with a double-constrained implant design after complex shoulder extra-articular resection

BackgroundApproximately, one-third of patients with tumors of proximal humerus will require an extra-articular resection to achieve oncologic margins. This procedure yields poor functional outcomes with a considerable rate of revisions. Unconstrained implants are prone to instability hindering also function of the elbow and hand, whereas constrained shoulder reconstructions suffer from early aseptic loosening of the glenoid component due to bone overload. The purpose of this study was to develop a constrained implant suitable for extra-articular resection with loss of function in deltoid and rotator cuff, which would provide both stability and passive motion, whilst also decreasing the risk of aseptic loosening of the glenoid component.MethodsIn cooperation with Czech Technical University in Prague, we devised an implant consisting of two constrained joints in series connected by a dumbbell piece. The biomechanical analysis showed a reduction of load transfer to the glenoid component with a torque of 8.6 Nm capable of generating an 865-N pulling force on bone screw to just 0.07 Nm, hence shielding the glenoid component from undesired forces and decreasing the risk of aseptic loosening. Three patients with extra-articular resection with a total loss of function of both rotator cuff and deltoid muscle received this type of reconstruction. The average follow-up was 16 months.ResultsThe surgical technique is straightforward. The surgery took 175 min on average with average blood loss of 516 ml. There were no surgical- or implant-related complications. All three patients were pain-free and had a stable shoulder joint after the reconstruction. All had fully functional elbow, wrist, and hand joints. The average Musculoskeletal Tumor Society (MSTS) score was 21/30 (70%). All patients were pleased with the results.ConclusionThe presented innovative implant design has demonstrated to be a promising alternative for reconstruction in these challenging cases.

A comparative probabilistic analysis of human and chimpanzee rotator cuff functional capacity.

Computational musculoskeletal modeling represents a valuable approach to examining biological systems in physical anthropology. Probabilistic modeling builds on computational musculoskeletal models by associating mathematical distributions of specific musculoskeletal features within known ranges of biological variability with functional outcomes. The purpose of this study was to determine if overlap in rotator cuff muscle force predictions would occur between species during the performance of an evolutionarily relevant horizontal bimanual arm suspension task. This necessitated creating novel probabilistic models of the human and chimpanzee glenohumeral joint through augmentation of previously published deterministic models. Glenohumeral musculoskeletal features of anthropological interest were probabilistically modeled to produce distributions of predicted human and chimpanzee rotator cuff muscle force that were representative of the specific anatomical manipulations. Musculoskeletal features modeled probabilistically included rotator cuff origins and deltoid insertion, glenoid inclination, and joint stability. Predicted human rotator cuff muscle force distributions were mostly limited to alternating between infraspinatus and teres minor, with both 100% and 0% muscle force predicted for both muscles. The chimpanzee model predicted low-to-moderate muscle force across all rotator cuff muscles. Rotator cuff muscle force predictions were most sensitive to changes of muscle origins and insertions. Results indicate that functional rotator cuff overlap is unlikely between chimpanzees and humans without greater modifications of the glenohumeral musculoskeletal phenotypes. The results also highlight the low efficacy of the human upper extremity in overhead, weight-bearing tasks, and propensity for rotator cuff injury.

Supraspinatus Tendon Reconstruction Using Fascia Lata Autograft for Irreparable Posterosuperior Massive Rotator Cuff Tears

Superior capsule reconstruction has shown good long-term clinical efficacy in treating irreparable posterosuperior massive rotator cuff tears. However, conventional superior capsule reconstruction did not treat the medial supraspinatus tendons. Therefore, dynamic function of the posterosuperior rotator cuff does not restore effectively, especially the function of active abduction and external rotation. We describe a supraspinatus tendon reconstruction technique that presents a stepwise approach to accomplish the dual goals of stable anatomic reconstruction and restoring the dynamic function of the supraspinatus tendon.

Shoulder arthroplasty in patients with glenohumeral osteoarthritis, glenoid bone loss and an intact rotator cuff: an algorithmic approach and review of the literature.

In patients with severe glenohumeral osteoarthritis (OA) and preserved rotator cuff function who have failed nonoperative treatment, anatomic total shoulder arthroplasty (TSA) has historically been the preferred surgical treatment. Shoulder arthroplasty in the setting of glenoid bone loss setting is technically demanding. Many techniques have been described to deal with glenoid bone loss including eccentric reaming, bone grafting, augmented glenoid baseplates, and patient-specific implants. Still, the decision to perform anatomic TSA or reverse total shoulder arthroplasty (RTSA) is often unclear, especially as the use of RTSA increases and evolves, making historical studies less useful when considering modern implant designs. RTSA has been advocated as a solution for patients with severe glenoid bone loss with intact rotator cuff function. Moreover, in appropriately selected patients, good outcomes can be achieved without the use of bone grafting or augmented baseplates. In cases of severe glenoid bone loss, RTSA can be performed with reaming the glenoid flat such that the baseplate rests on native glenoid bone. We have previously reported excellent prosthetic survival with this technique at 5-year follow-up. The purpose of this article is to highlight our suggested treatment algorithm for glenohumeral OA with glenoid bone loss and intact rotator cuff. Specifically, we focus on situations where RTSA may be preferred as opposed to anatomic TSA, and our suggested approach to managing bone loss intraoperatively in this complex patient population.

Avascular Necrosis and Posttraumatic Arthritis After Proximal Humerus Fracture Internal Fixation: Evaluation and Management.

Avascular necrosis (AVN) and posttraumatic arthritis (PTA) are common complications following both conservative treatment and open reduction and internal fixation (ORIF) of proximal humerus fractures (PHFs). Despite the frequent utilization of ORIF, information regarding these leading causes of failure is limited. This review includes a discussion of incidence, risk factors, and evaluation of AVN and PTA following PHF. The mechanisms of treatment options and associated outcomes are also reviewed. Recent best available evidence demonstrates significant rates of AVN and PTA following ORIF of PHF. This is particularly true of complex fracture patterns. A thorough workup is required in the setting of failure caused by AVN and PTA. This includes a careful patient history, clinical exam, plain film radiographs, and CT scans. EMG and/or aspiration may also be indicated. Special consideration is given to the examination of the deltoid muscle, neurovascular status, rotator cuff function, and the possibility of infection. Biological supplementation, anatomic total shoulder replacement (aTSA), and fusion are rarely employed in the treatment of AVN and/or PTA. Due to satisfactory patient outcomes, reverse total shoulder replacement (rTSA) has increased in popularity for the elderly population, while hemiarthroplasty (HA) may be appropriate for some young, active patients. With careful patient selection and meticulous surgical technique, AVN and PTA can be mitigated. Careful indications for ORIF may decrease the frequency of these complications. For most patients, rTSA is the optimal treatment option. Given the frequent utilization of ORIF and the higher than acceptable complication and failure rates, AVN and PTA warrant our attention.

Treatment options for massive irreparable rotator cuff tears: a review of arthroscopic surgical options.

While functional reconstruction of massive irreparable rotator cuff tears remains a challenge, current techniques aimed at recentering and preventing superior migration of the humeral head allow for clinical and biomechanical improvements in shoulder pain and function. Recentering of the glenohumeral joint reduces the moment arm and helps the deltoid to recruit more fibers, which compensates for insufficient rotator cuff function and reduces joint pressure. In the past, the concept of a superior capsular reconstruction with a patch secured by suture anchors has been used. However, several innovative arthroscopic treatment options have also been developed. The purpose of this article is to present an overview of new strategies and surgical techniques and if existing present initial clinical results. Techniques that will be covered include rerouting the long head of the biceps tendon, utilization of the biceps tendon as an autograft to reconstruct the superior capsule, utilization of a semitendinosus tendon allograft to reconstruct the superior capsule, superior capsular reconstruction with dermal allografts, and subacromial spacers.

Implant selection for successful reverse total shoulder arthroplasty.

Reverse total shoulder arthroplasty (RTSA) emerged as a new concept of arthroplasty that does not restore normal anatomy but does restore function. It enables the function of the torn rotator cuff to be performed by the deltoid and shows encouraging clinical outcomes. Since its introduction, various modifications have been designed to improve the outcome of the RTSA. From the original cemented baseplate with peg or keel, a cementless baseplate was designed that could be fixed with central and peripheral screws. In addition, a modular-type glenoid component enabled easier revision options. For the humeral component, the initial design was an inlay type of long stem with cemented fixation. However, loss of bone stock from the cemented stem hindered revision surgery. Therefore, a cementless design was introduced with a firm metaphyseal fixation. Furthermore, to prevent complications such as scapular notching, the concept of lateralization emerged. Lateralization helped to maintain normal shoulder contour and better rotator cuff function for improved external/internal rotation power, but excessive lateralization yielded problems such as subacromial notching. Therefore, for patients with pseudoparalysis or with risk of subacromial notching, a medial eccentric tray option can be used for distalization and reduced lateralization of the center of rotation. In summary, it is important that surgeons understand the characteristics of each implant in the various options for RTSA. Furthermore, through preoperative evaluation of patients, surgeons can choose the implant option that will lead to the best outcomes after RTSA.

The relationship between handgrip and rotator cuff muscle strength in shoulder pain: a cross-sectional study

Background/Aims Shoulder pain is reported to be the third most common musculoskeletal disorder. Rotator cuff muscles play an important role in stabilising the shoulder and decreasing pain. Assessment of handgrip strength has been proposed as an indicator of rotator cuff function in healthy individuals, but not in those experiencing shoulder pain. The aim of this study was to assess the relationship between handgrip strength and shoulder rotator cuff strength in patients experiencing shoulder pain as a result of pathology or surgical intervention. A secondary aim was to identify any association between the duration of shoulder pain and handgrip strength and shoulder rotator cuff strength. Methods A total of 32 patients with shoulder pain (19 men, 13 women) were evaluated. The mean age was 52.88 (± 15.66) years, with a mean duration of shoulder pain of 13.44 (± 10.22) weeks. Handgrip strength was measured using the standard Jamar hydraulic hand dynamometer, and individual isometric rotator cuff strength was measured using the Baseline push-pull dynamometer. Results Correlation was found between handgrip strength and the abductor (r=0.58), external rotator (r=0.57), and internal rotator strength (r=0.59). A linear regression model was used to derive the equations for the association. No significant (P&gt;0.05) correlation was found between the duration of pain and the handgrip strength or rotator cuff strength. Conclusions The strength of the correlation found indicates that handgrip strength can be used for assessment and within a rehabilitation programme to monitor rotator cuff function in patients with shoulder pain or post-surgical rehabilitation. The strength of rotator cuff muscles can be predicted by the equations derived from the regression model relating to grip strength assessment.

Different Surgeries, Same Result?: Commentary on an article by Jacob M. Kirsch, MD, et al.: "Outcomes After Anatomic and Reverse Shoulder Arthroplasty for the Treatment of Glenohumeral Osteoarthritis. A Propensity Score-Matched Analysis".

Commentary In their study, Kirsch and colleagues evaluated the outcomes of anatomic (TSA) and reverse (RSA) total shoulder arthroplasty for the treatment of glenohumeral osteoarthritis in patients with an intact rotator cuff. In this retrospective, matched-cohort study, short-term results demonstrated improved patient-reported outcomes and a low rate of complications in both groups, with slightly better range of motion in the TSA group. This article is of interest due to the increasing prevalence of and expanding indications of RSA. In this study, matching was performed using preoperative function and patient-specific factors to better compare the outcomes of both implant designs. However, selection bias is still a limitation of this study design. Patients were selected for TSA or RSA based on surgeon preference; this implies differences between the groups that factored into the surgeon’s decision, which may impact the results. Additionally, the procedures were performed by a single surgeon with extensive shoulder arthroplasty experience. This should give readers pause when interpreting the results and how these results impact each surgeon’s current practice. There is evidence that surgeon experience leads to superior results for RSA1,2, although it does appear that improvements in training and implant design are narrowing this gap3. The results of this study showed generally similar improvement postoperatively among patients with matched preoperative ASES scores. This finding may contrast reports that show an association between patient dissatisfaction with TSA when the preoperative ASES score is lower4 and dissatisfaction with RSA when the preoperative ASES score is higher5. The conflict may be due to patient sampling and inherent difficulty with cohort matching. As stated earlier, the retrospective nature of the study by Kirsch et al. does raise questions about how the decision was made to perform TSA or RSA in otherwise similar patients. When weighing the risk of revision of TSA due to rotator cuff failure and aseptic glenoid loosening against slightly greater improvements in range of motion, it is tempting to move our indications toward RSA in older and lower-demand patients. However, using survivorship free from revision as the primary factor in deciding to perform RSA may be short-sighted. The complications and failures of TSA and RSA are as different and unique as the implants themselves. When considering revision rates, care should be taken to acknowledge that revision may not be an option in what is otherwise considered to be a failed implant or poor patient outcome after RSA. In a recent large database study comparing the complication and revision rates of these implants at a mean of 30 months, Parada et. al. reported that revision rates were higher for TSA yet complications rates were similar3. This discordance is largely driven by issues such as acromial insufficiency fracture and persistent pain—complications that are 2 of the 3 most frequently encountered complications associated with RSA. These complications not only lead to compromised patient outcomes but also do not have reliable solutions. In contrast, TSA failure can be corrected with revision to RSA in most circumstances. Certainly, we aim to make each patient’s first procedure their last procedure; however, issues such as those mentioned above should not be ignored. Additional research is needed to compare TSA and RSA in similar patient populations (as was done in this study) focusing on intermediate to long-term outcomes. Kirsch and colleagues have contributed valuable information to the debate between TSA and RSA in patients with osteoarthritis and should be congratulated for doing so. Matched cohort studies help to shed light on the differences and similarities associated with these procedures, but longer-term follow-up is needed. Ultimately, a prospective randomized trial is needed for true comparison between these 2 procedures. The decision to perform TSA or RSA is complex and involves multiple patient and surgeon-related factors. Despite the evidence presented in this study, TSA is still our preferred treatment for most patients with osteoarthritis and a functional rotator cuff.

Numerical and Experimental Investigations of Humeral Greater Tuberosity Fractures with Plate Fixation under Different Shoulder Rehabilitation Activities

The incidence of humerus greater tuberosity (GT) fractures is about 20% in patients with proximal humerus fractures. This study aimed to investigate the biomechanical performances of the humerus GT fracture stabilized by a locking plate with rotator cuff function for shoulder rehabilitation activities. A three-dimensional finite element model of the GT-fracture-treated humerus with a single traction force condition was analyzed for abduction, flexion, and horizontal flexion activities and validated by the biomechanical tests. The results showed that the stiffness calculated by the numerical models was closely related to that obtained by the mechanical tests with a correlation coefficient of 0.88. Under realistic rotator cuff muscle loading, the shoulder joint had a larger displacement at the fracture site (1.163 mm), as well as higher bone stress (60.6 MPa), higher plate stress (29.1 MPa), and higher mean screw stress (37.3 MPa) in horizontal flexion rehabilitation activity when compared to that abduction and flexion activities. The horizontal flexion may not be suggested in the early stage of shoulder joint rehabilitation activities. Numerical simulation techniques and experimental designs mimicked clinical treatment plans. These methodologies could be used to evaluate new implant designs and fixation strategies for the shoulder joint.

POSSIBILITIES OF ENDOPROSTHETICS IN PATIENTS WITH THE CONSEQUENCES OF SHOULDER JOINT INJURIES

The use of shoulder joint replacement has increased significantly since the early 2000s. The method, initially used as the gold standard for the treatment of osteoarthritis, has long gone beyond the generally accepted indications, expanding its use for the treatment of shoulder joint injuries and their consequences. The new generation of implants has led to improved outcomes such as functionality, range of motion in the shoulder joint and patient satisfaction. The decision to perform anatomical endoprosthetics (hemiarthroplasty, total shoulder joint replacement) depends on the degree of osteopenia, the viability of the humerus head, the integrity of the tubercles or the functional state of the rotator cuff of the shoulder. This type of arthroplasty remains for patients with a functional rotator cuff. Reversible endoprosthetics is today the preferred treatment option for non-fusion or improper fusion of the proximal humerus with a collapse of the humerus head or a non-functioning rotator cuff. Despite the limitations and complications reported in the literature, revision arthroplasty has a good potential for functional improvement in patients with the consequences of injuries of the proximal humerus. This is a group of patients, which is a difficult task for a surgeon. As further research is carried out, implant designs and their clinical application will continue to evolve.

Can the reverse total shoulder arthroplasty provide as good of an outcome as an anatomic shoulder arthroplasty

BackgroundReverse total shoulder arthroplasty (RTSA) is an excellent treatment option for a variety of shoulder pathologies. Anatomic total shoulder arthroplasty (TSA) remains an excellent treatment for patients with glenohumeral arthritis and a functioning rotator cuff. RTSA has become a much more common procedure than TSA in recent times. It is currently unclear if patients who have a good outcome following TSA outperform patients who have a good outcome following RTSA. The purpose of this study was to compare the 2-year outcomes of patients with good outcomes, defined as having forward flexion of >130° and American Shoulder and Elbow Surgeons score of >70, following TSA and RTSA. MethodsAll patients who underwent TSA or RTSA between 2015 and 2019 with minimum 2-year follow-up were eligible for inclusion. Patients were included if their postoperative forward flexion was >130° and American Shoulder and Elbow Surgeons score was >70. Patients were excluded if they were a revision surgery, were treated with an arthroplasty for fracture, or had a latissimus transfer. Demographic variables were analyzed between groups. Range of motion (ROM), strength, and patient-reported outcome (PRO) scores were compared between groups. ResultsOverall, 318 TSAs were included; 155 (49%) met the criteria for a “good” outcome. Among RTSAs, 428 were included; 154 (36%) met the criteria for a “good” outcome. When comparing PROs between groups, RTSA patients had worse preoperative and postoperative PRO scores (all P < .05). When comparing preoperative physical examination findings, RTSA patients had worse ROM and strength (all P < .05) and worse Constant Power scores and Constant scores (P < .001 in both cases). Postoperatively, RTSA patients had worse ROM and strength (all P < .05) and worse Constant scores (P = .028). The magnitude of change (delta) from preoperative to postoperative function was often greater following RTSA than TSA. There were no significant differences in whether expectations were met or exceeded between RTSA and TSA patients in regards to pain control (99% vs. 98%; P = .177), motion and strength (93% vs. 96%; P = .559), ability to return to activities of daily living (98% vs. 99%; P = .333), or return to sporting activities (95% vs. 91%; P = .268). ConclusionPatients do well following both TSA and RTSA. In patients who have a good outcome following either TSA or RTSA, those patients who underwent TSA have superior outcomes to patients following RTSA. However, the change in outcome scores from pre- to post-surgery is often more significant with RTSA, as they often start out with worse motion and clinical scores.