Anatomical total shoulder arthroplasty revision to reverse shoulder arthroplasty using convertible glenoid: a systematic review of clinical and radiological outcomes.

PURPOSE: The aim of the present systematic review is to collect all the available evidence regarding the clinical and radiological results of revision to reverse shoulder arthroplasty (RSA) of modular anatomic shoulder prostheses (TSA) using a convertible metal-backed glenoid (MBG). METHODS: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies investigating revision of TSA to RSA utilizing a convertible MBG and reporting clinical and radiological outcomes were identified. RESULTS: A total of five studies on the use of convertible modular glenoid component in the setting of TSA revision to RSA were finally included in the present systematic review. A total of 60 procedures were reported. Mean operative times was 65 min. Intraoperative complications included 3 cases of glenoid loosening. Only one case of dislocation was reported as postoperative complication. At mean follow-up of 32.3 months post-revision, no glenoid loosening was reported, VAS score decreased from 7.7 to 1.5, Constant Score increased from 24.8 to 57.6. CONCLUSIONS: Revision to RSA after failed TSA using a convertible modular glenoid component was associated with a low rate of intraoperative and postoperative complications, low surgical time and led to good results in term of pain relieve and functional outcomes. Given the complexity and risk associated with revision of anatomic shoulder prosthesis having a convertible glenoid may help to simplify the procedure and improve clinical results.

Glenoid bone loss in anterior shoulder dislocation: a multicentric study to assess the most reliable imaging method.

PURPOSE: The aim of this multicentric study was to assess which imaging method has the best inter-reader agreement for glenoid bone loss quantification in anterior shoulder instability. A further aim was to calculate the inter-method agreement comparing bilateral CT with unilateral CT and MR arthrography (MRA) with CT measurements. Finally, calculations were carried out to find the least time-consuming method. METHOD: A retrospective evaluation was performed by 9 readers (or pairs of readers) on a consecutive series of 110 patients with MRA and bilateral shoulder CT. Each reader was asked to calculate the glenoid bone loss of all patients using the following methods: best fit circle area on both MRA and CT images, maximum transverse glenoid width on MRA and CT, CT PICO technique, ratio of the maximum glenoid width to height on MRA and CT, and length of flattening of the anterior glenoid curvature on MRA and CT. Using Pearson's correlation coefficient (PCC), the following agreement values were calculated: the inter-reader for each method, the inter-method for MRA with CT quantifications and the inter-method for CT best-fit circle area and CT PICO. Statistical analysis was carried out to compare the time employed by the readers for each method. RESULTS: Inter-reader agreement PCC mean values were the following: 0.70 for MRA and 0.77 for CT using best fit circle diameter, 0.68 for MRA and 0.72 for CT using best fit circle area, 0.75 for CT PICO, 0.64 for MRA and 0.62 for CT anterior straight line and 0.49 for MRA and 0.43 for CT using length-to-width ratio. CT-MRA inter-modality PCC mean values were 0.9 for best fit circle diameter, 0.9 for best fit circle area, 0.62 for anterior straight line and 0.94 for length-to-width methods. PCC mean value comparing unilateral CT with PICO CT methods was 0.8. MRA best fit circle area method was significantly faster than the same method performed on CT (p = 0.031), while no significant difference was seen between CT and MRA for remaining measurements. CONCLUSIONS: CT PICO is the most reliable imaging method, but both CT and MRA can be reliably used to assess glenoid bone loss. Best fit circle area CT and MRA methods are valuable alternative measurement techniques.

Cost-effectiveness analysis of arthroscopic Bankart repair versus open Latarjet reconstruction in anterior shoulder instability.

PURPOSE: The ideal surgical treatment for anterior shoulder instability is still under debate. In the healthcare setting, both clinical and economic factors must be considered for optimal resource allocation. From the clinical perspective, the Instability Severity Index Score (ISIS) is a helpful and validated tool for surgeons, although a gray area between 4 and 6 exists. In fact, patients with an ISIS < 4 and > 6 can be treated effectively with arthroscopic Bankart repair and open Latarjet, respectively. The purpose of this study was to conduct a cost-effectiveness analysis of arthroscopic Bankart repair versus open Latarjet in patients with an ISIS between 4 and 6. METHODS: A decision-tree model was constructed to simulate the clinical scenario of an anterior shoulder dislocation patient with an ISIS between 4 and 6. Based on previously published literature, outcome probabilities and utility values in the form of Western Ontario Instability Score (WOSI) were assigned to each branch of the tree, alongside institutional cost. The primary outcome assessed was an Incremental cost-effectiveness ratio (ICER) of the two procedures. Eden-Hybbinette was also considered in the model as a salvage procedure for failed Latarjet. A two-way sensitivity analysis was performed to identify the most impactful parameters on the ICER upon their variation within a pre-determined interval. RESULTS: Base case cost was 1245.57 € (1220.48-1270.65 €) for arthroscopic Bankart repair, 1623.10 € (1580.82-1665.39 €) for open Latarjet and 2.373.95 € (1940.81-2807.10 €) for Eden-Hybbinette. Base-case ICER was 9570.23 €/WOSI. Sensitivity analysis showed that the most impactful parameters were the utility of arthroscopic Bankart repair, the probability of success of open Latarjet, the probability of undergoing surgery after post-operative recurrence of instability and the utility of Latarjet. Of these, utility of arthroscopic Bankart repair and Latarjet had the most significant impact on the ICER. CONCLUSION: From a hospital perspective, open Latarjet was more cost-effective than arthroscopic Bankart repair in preventing further shoulder instability in patients with an ISIS between 4 and 6. Despite its several limitations, this is the first study to analyze this subgroup of patients from a European hospital setting from both an economic and clinical perspective. This study can help surgeons and administrations in the decision-making process. Further clinical studies are needed to prospectively analyze both aspects to further delineate the best strategy.

Does arthroscopic superior capsule reconstruction using porcine dermal xenograft represent a viable option in case of massive irreparable posterosuperior rotator cuff tear?

INTRODUCTION: The aim of the present study was to evaluate clinical and structural outcomes of patients with a massive irreparable rotator cuff tear treated with arthroscopic superior capsule reconstruction using an acellular porcine dermal xenograft. We hypothesized that this procedure would lead to improvement in clinical and functional results and that structural failure would not influence the final clinical results. MATERIALS AND METHODS: A retrospective analysis on arthroscopic superior capsule reconstruction performed from October 2016 to January 2019 was conducted. The procedure was performed in patients with a massive irreparable posterosuperior rotator cuff tear without a severe glenohumeral arthropathy (Hamada I and II) and complaining a painful pseudoparalysis. Clinical evaluation and MRI study were performed before surgery and after at least 14 months. RESULTS: A comprehensive group of 21 patients with 11 females and 10 males and a mean age of 57 ± 8.5 years underwent arthroscopic superior capsule reconstruction. The graft had a thickness of 1.5 mm in the first 9 cases (43%) since it was used in a single layer. The graft was thereafter doubled for technique evolution in the following 12 cases (57%) achieving a graft thickness of 3 mm. Active ROM significantly improved with a mean increase of active forward flexion from 72.8° ± 7.5° to 120.6° ± 4.5°, active abduction from 68.3° ± 10.2° to 140.2° ± 8.8° and external rotation from 38.2° ± 11.2° to 56.7° ± 6.8° at the last follow-up. The mean Constant score significantly improved from 40.4 ± 6.7 to 73.3 ± 8.2. A graft tear revealed in 52% (11/21) of overall patients was significantly more frequent in single layer graft when compared to double layer (77% vs 33%, p < 0.05). Location and type of graft tear significantly influenced final outcomes. Patients with a healed (graft continuity with bone at medial and lateral insertion) or medial graft tear showed statistically significant better outcomes when compared with patients in which the graft was completely reabsorbed or torn on humeral side (p < 0.05). CONCLUSION: Arthroscopic superior capsule reconstruction using an acellular porcine dermal xenograft may be a viable alternative to treat massive posterosuperior rotator cuff tear in patients with a painful pseudoparalysis without anterosuperior escape. Structural failure may strongly influence final outcomes with significant role played by tear location.

Shoulder replacement: an epidemiological nationwide study from 2009 to 2019.

BACKGROUND: Shoulder replacement (SR) constitutes the gold standard treatment for severe shoulder diseases, including osteoarthritis, rheumatoid arthritis, complex fractures, avascular necrosis and rotator cuff arthropathy. Although several countries have national registries, there is a lack of epidemiological data on SR. Sharing national statistics and correlating those to other countries could be helpful to compare outcomes and costs internationally. This paper aims to evaluate the trend of hospitalizations for SR (both first implants and revisions of anatomical and reverse prosthesis) in Italy from 2009 to 2019, based on the National Hospital Discharge Reports (S.D.O) provided by the Italian National Health Service (INHS). Moreover, the economic impact on the healthcare system of SR and SR revisions was assessed, providing a statistical prediction for the next ten years. METHODS: The data used in this paper were about patients who underwent Total Shoulder Replacement (TSR), Shoulder Hemiarthroplasty (SH) or Revision of shoulder joint replacement (RSR) from 2009 to 2019 in Italy. Information about patients was anonymous and included age, sex, days of hospitalization, procedures and diagnoses codes. RESULTS: From 2009 to 2019, 73,046 TSR and SH were performed in adult Italian residents, with a cumulative incidence of 13.6 cases per 100,000 adult Italian residents. While, 2,129 revisions of shoulder replacement were performed, with a cumulative incidence of 0.4 cases per 100,000 residents. Overall, females represented the majority of the cases (72.4% of patients who underwent TSR or SH and 59.1% of patients who underwent RSR). From 2009 to 2019, has been assessed an overall cost of 625,638,990€ for TSR or SH procedures in Italy. While, an overall cost of 9,855,141€ for RSR procedures in Italy was calculated. CONCLUSIONS: The incidence of SR and RSR is expected to increase in the following years, constituting a burden for the healthcare systems. Overall, in Italy, the females represented the majority of patients. Further prospective studies on this topic in different countries can be con-ducted to make comparisons.

Measuring the critical shoulder angle on radiographs: an accurate and repeatable deep learning model.

PURPOSE: Since the critical shoulder angle (CSA) is considered a risk factor for shoulder pathology and the intra- and inter-rater variabilities in its calculation are not negligible, we developed a deep learning model that calculates it automatically and accurately. METHODS: We used a dataset of 8467 anteroposterior x-ray images of the shoulder annotated with 3 landmarks of interest. A Convolutional Neural Network model coupled with a spatial to numerical transform (DSNT) layer was used to predict the landmark coordinates from which the CSA was calculated. The performances were evaluated by calculating the Euclidean distance between the ground truth coordinates and the predicted ones normalized with respect to the distance between the first and the second points, and the error between the CSA angle measured by a human observer and the predicted one. RESULTS: Regarding the normalized point distances, we obtained a median error of 2.9%, 2.5%, and 2% for the three points among the entire set. Considering CSA calculations, the median errors were 1° (standard deviation 1.2°), 0.88° (standard deviation 0.87°), and 0.99° (standard deviation 1°) for angles below 30°, between 30° and 35°, and above 35°, respectively. DISCUSSION: These results demonstrate that the model has the potential to be used in clinical settings where the replicability is important. The reported standard error of the CSA measurement is greater than 2° that is above the median error of our model, indicating a potential accuracy sufficient to be used in a clinical setting.

Rotator cuff repair protected with subacromial balloon spacer shows a low rate of non-healing.

PURPOSE: The purpose of this study was to evaluate clinical outcomes and tendon integrity on magnetic resonance imaging (MRI) of chronic posterosuperior rotator cuff tears treated with single-row tensionless repair and subacromial balloon spacer as protection with a minimum follow-up of 2 years. The hypothesis of this study was that this procedure would have acceptable clinical outcomes and tendon-healing rate without increased complications. METHODS: This is a retrospective study of patients with chronic posterosuperior rotator cuff tears repaired with a single-row technique protected with a subacromial balloon device. Patients were followed up for a minimum of 2 years. Clinical outcomes were evaluated with American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and Numerical Rating Scale (NRS) for pain. MRI study was obtained likewise after at least 2 years to assess tendon-healing rate. Statistical comparison was performed between pre-operative and at least 2-year clinical and imaging follow-up. RESULTS: Thirty-two patients were included in the study with a mean follow-up of 27 ± 7 (range 24-48). The mean age of this cohort was 58 ± 6 (range 41-66) including 15 males and 17 females. The tear size was on average 2.3 cm (range 2-4) and a mean of 2.1 triple-loaded anchors were used (range 2-3). The ASES score significantly increased from a mean of 39 ± 12 points to a mean of 89 ± 12 at the final follow-up (P < 0.001). Similarly, pain significantly reduced from a mean pre-operative NRS of 6.8 ± 1.4 to 0.8 ± 1.5 at the final follow-up (P < 0.001). MRI scans showed that repair occurred in 26 patients (81.3%). Significant higher ASES score was reached at final follow-up in patients with a "healed" (Sugaya I-III) tendon when compared to patients with an evidence of tendon discontinuity on MRI study (Sugaya IV-V), 93 ± 9 and 74 ± 13, respectively (P < 0.001). CONCLUSIONS: Arthroscopic repair of chronic posterosuperior rotator cuff tears using a single-row tensionless repair and subacromial spacer as protection resulted in an 81.3% of tendon integrity at a mean follow-up of 27 months. Clinical outcomes and pain scores significantly improved without severe complications reported after a minimum follow-up of 2 years. LEVEL OF EVIDENCE: III.

Long head biceps tendon instability: diagnostic performance of known and new MRI diagnostic signs.

OBJECTIVE: The aim of this work was to evaluate the inter-observer agreement and diagnostic performance values of 7 MRI signs (3 known and 4 new) of long head biceps tendon instability. MATERIALS AND METHODS: MRI of 86 patients were retrospectively evaluated. Inter-observer agreement and diagnostic performance of each diagnostic sign and of all combined signs (with the exception of detour sign) were tested for identification of biceps tendon instability, with arthroscopy as the reference standard. RESULTS: Agreement between expert operators was moderate to good. Sensitivity, specificity, and sign accuracy showed a variation respectively of the following: humeral chondral print 72-80%, 62-68%, and 70-76%; subchondral bone edema 24-31%, 84-97%, and 50%; biceps tendon angle 60-71%, 97-100%, and 74-81%, biceps tendon-groove distance 31-47%, 90-100%, and 56-64%; long head biceps subluxation/dislocation on axial plane 49-53%, 97-100%, and 66-70%; displacement sign 74-80%, 74-100%, and 74-87%; detour sign 51-64%, 58-81%, and 62-64%; and all signs 98-100%, 32-61%, and 75-86%. CONCLUSION: These diagnostic signs, both known and new, individually and/or in combination, provide a valid tool in the MRI diagnosis of long head biceps tendon instability.

Editorial Commentary: Acute Repair of the Acromioclavicular Joint Capsule and Ligaments and Deltotrapezial Fascia Could Allow Biological Healing of High-Grade Acromioclavicular Separation-Coracoclavicular Ligament Graft Augmentation Could Be Indicated if Time to Surgery Is Greater Than 3 Weeks.

Surgical management of chronic acromioclavicular joint (ACJ) dislocations is a matter of controversy. In the acute setting of high-grade acromioclavicular separation, if a surgical repair of the ACJ capsule and ligaments and deltotrapezial fascia could allow biological healing of the ligaments themselves, this could be enough to restore the functional biomechanics of the joint; unfortunately, this is not true for chronic cases. In the latter situation, a surgical technique using biological augmentation such as autograft or allograft should be preferred. Time is very important for this injury, and a chronic lesion should be considered when treatment is being performed 3 weeks after trauma. The graft should be passed around the base of the coracoid or through a tunnel at the base of the coracoid itself and then at the level of the clavicle as anatomically possible to reproduce the function of the native ligaments. However, some studies have shown that passing the graft at the base of the coracoid and wrapping it around the clavicle could also achieve satisfactory outcomes. An arthroscopic technique, when used in combination, could be great to treat the associated lesions, which have a reported percentage between 30% and 49%. Finally, to restore the biomechanics of the ACJ, however, reconstruction of the acromioclavicular superior and posterior capsules together with the deltotrapezial fascia seems to be very important.

Elite professional goalkeepers report high rate of sport resumption after shoulder surgery.

PURPOSE: The aim of this study is to evaluate the return to sport after surgical treatment of shoulder injuries in professional goalkeepers in relationship with the mechanism of injury and the pattern of related shoulder lesions. METHODS: Twenty-six shoulders in nineteen elite male professional soccer goalkeepers were retrospectively analyzed considering multiple diseases (instability, rotator cuff, biceps or other tendon injuries). Data was collected for injury modality and context, pathological findings, surgical procedures, time, level of return to sport, and complications. RESULTS: The mechanism of injury was "mild trauma without contact" in 46% of the cases and 54% of injuries happened during training. 11 patients (42%) reported multiple pattern lesions and 9 patients (35%) classic anterior instability lesions. The mean time for return to differentiated training and unrestricted sport activity was 14 and 20.2 weeks, respectively. 15 athletes (62.5%) reported 100% return to sport, 4 (16.7%) to 90%, 1 (4.2%) to 85%, 3 (12.5%) to 80% and 1 athlete to 50%, stopping professional activity. 21% of the cases reported the persistence of some shoulder symptoms. 3 cases experienced a new injury. Patients with classic anterior instability had significantly lower age (30.7 vs 19.8 years, P = 0.001), experienced injury in different context and reported symptoms more frequently compared to multiple lesion patients (4/8 vs 0/10, P = 0.011). CONCLUSION: Professional elite goalkeepers which required shoulder surgery for different causes demonstrated high-rate level of return to play despite the persistence of mild symptoms. The high frequency of multiple lesions, patients' characteristics, injury context and mechanism, increase the concern for injuries in overstressed shoulder for this category of sport. LEVEL OF EVIDENCE: IV.

US-guided percutaneous irrigation of calcific tendinopathy of the rotator cuff in patients with or without previous external shockwave therapy.

OBJECTIVES: To compare the outcome of US-guided percutaneous irrigation of calcific tendinopathy (US-PICT) of the rotator cuff in patients with or without previous external shockwave therapy (ESWT). METHODS: We analyzed all patients treated with US-PICT from March 1, 2016, to October 1, 2019, with shoulder pain refractory to conservative management for rotator cuff calcific tendinopathy, diagnosed with ultrasound. Each patient was examined using the Constant-Murley Score (CMS) questionnaire (score 0-100) before and after treatment. We tested CMS differences using the Mann-Whitney U (Wilcoxon rank-sum) test in the two groups. US-PICT was performed placing two or multiple 14G needles, according to the calcification size, inserted under US guidance to create a circuit of irrigation in the calcified tendon. NaCl solution at 38 °C was then injected from the entry needle in a variable amount to hydrate and fragment the calcification, finally allowing for its expulsion through the exit needle. All patients also received an intrabursal steroid injection. RESULTS: From 2016 to 2019, 72 US-PICT treatments were performed on 70 patients (females = 46; males = 26) with a mean age of 49.7 years (SD = 8.7. Thirty-three (47%) underwent previous ESWT, while thirty-seven (53%) had no previous treatments. No treatment-related complications were observed. Follow-up was averagely 14.4 months (median = 11.6, SD = 11.9, range 1-45); 37 patients had a follow-up shorter than 12 months (1-11.6); 35 patients were visited after more than 1 year (12.2-45.6, Table W). Before treatment, the mean CMS was 35 (SD = 21); after treatment, it reached 75.4, with an average CMS improvement of 40.3 points (SD = 23.7, p < 0.001). The comparison of improvement between the ESWT and non-ESWT group yielded no significant difference (p = 0.3). CONCLUSIONS: US-PICT of the rotator cuff is an effective procedure to reduce shoulder pain and increase mobility in patients with calcific tendinopathy, both in short- and long-term time intervals. Previous unsuccessful ESWT does not affect the outcome of US-PICT.

Intra-articular long head of the biceps tendon: magnetic resonance-arthrography classification and review of literature.

PURPOSE: Anatomical variants of the long head of the biceps (LHB) and diseases of the rotator interval structures may contribute to shoulder instability. The rotator interval and the LHB tendon are closely associated anatomic structures that confer stability to the shoulder. Anatomical variants around the origins of the long head of the biceps (LHB) are reported to occur with a frequency of 1.9-7.4%. In the past years, many authors have proposed different approaches for the identification and characterization of LHB and rotators interval. Magnetic resonance (MR) arthrography is considered the reference standard in imaging to diagnose superior shoulder diseases. However, few authors have analysed the anatomical variants and the relation between those and shoulder instability. This study aimed to identify the frequency of variants observed during arthroscopic shoulder surgeries, and to classify them based on the Dierickx classification system. MATERIAL AND METHODS: In 326 MR arthrograms we investigated the incidence of LHB anatomical variations and their association with shoulder diseases. RESULTS: We found 252/326 (77.3%) cases of LHB free, 40/326(12.26%) cases of LHB adherent, 31/326(9.50%) cases of mesotenon, and 3/326(0.9%) cases of split biceps. The prevalence of rotator interval synovitis in the mesotenon group was greater than in the LHB-free group. Moreover, in the LHB-adherent group we observed increased incidence of sublabral recess and SLAP lesions compared with the LHB-free group. CONCLUSIONS: MR-arthrography is useful in the evaluation of superior shoulder structures. A relationship exists between LHB anomalies and superior shoulder instability.

Imaging of shoulder instability.

The shoulder enjoys the widest range of motion of all the joints in the human body, therefore requires a delicate balance between stability and motility. The glenohumeral joint is inclined to fall into two main instability categories: macro and micro. Macroinstability can be traumatic or atraumatic, with anterior or posterior dislocation of the humeral head. Microinstability falls within the broader section of acquired instability in overstressed shoulder caused by repeated joint stress. Anterior traumatic instability is the most frequent entity and a relatively common injury in young and athletic population. While shoulder instability is a clinical diagnosis, imaging impacts the patient management by detailing the extent of injury, such as capsulo-labral-ligamentous tears, fracture, and/or dislocation, describing the predisposing anatomic conditions and guide the therapetic choice. The aim of this comprehensive review is to cover the imaging findings of shoulder instability by different imaging techniques.

Is the Instability Severity Index Score a Valid Tool for Predicting Failure After Primary Arthroscopic Stabilization for Anterior Glenohumeral Instability?

PURPOSE: To assess the validity of the Instability Severity Index Score in predicting the rate of recurrence of dislocation in patients undergoing arthroscopic Bankart repair. METHODS: The inclusion criteria were recurrent anterior traumatic glenohumeral instability and a minimum follow-up of 5 years. According to the preoperative Instability Severity Index Score, patients were divided into the following groups: ≤3 points (A), 4 to 6 points (B), and >6 points (C). The recurrence rate was determined by telephone interviews. The estimated overall rate of success at 5 years was defined as the estimated overall percentage of patients free of recurrence at 5 years. RESULTS: Six hundred seventy patients (572 men and 98 women) were included. The average age was 27 years (range, 18 to 39 years) at the time of surgery. One hundred fourteen of 670 patients had a recurrence of instability, with an overall recurrence rate of 17% (95% confidence interval [CI] 14.2%-19.9%). The Instability Severity Index Score had a significant association with recurrence. Compared with patients in group A, those in group B had double the risk of recurrence (hazard ratio [HR] = 2.43, 95% CI 1.38-4.28, P = .002), and patients in group C a 9 times greater risk of recurrence (HR = 9.42, 95% CI 5.20-17.7, P < .001). The estimated overall rate of success at 5 years was 84.8% (95% CI 81.8-87.3). The rate of success with an Instability Severity Index Score ≤3 points was 93.7% (95% CI 89.6-96.2), but it dropped to 85.7% (95% CI 81.7-88.9) in those with an Instability Severity Index Score of 4 to 6 points and became 54.6% (95% CI 42.8-64.9) in those with an Instability Severity Index Score >6 points. On multivariable analysis, the Instability Severity Index Score was found to significantly affect the risk of recurrence, corrected by type of sport and glenoid bone loss. CONCLUSIONS: The Instability Severity Index Score is a validated tool with which to assess the recurrence rate of dislocation after arthroscopic surgery in patients with shoulder instability. Arthroscopic stabilization in patients with an Instability Severity Index Score ≤3 is associated with a significantly lower risk of recurrence of glenohumeral instability compared with that in patients with an Instability Severity Index Score >3 points. LEVEL OF EVIDENCE: III, case-control study.

Biomechanics of lower trapezius and latissimus dorsi transfers in rotator cuff-deficient shoulders.

BACKGROUND: Irreparable posterosuperior rotator cuff tears cause pain and impaired shoulder function. Latissimus dorsi (LD) transfer has been proven to improve shoulder function, but lower trapezius (LT) transfer has recently been proposed as an alternative. This study aimed to compare the biomechanics of LD and LT transfers and how they are affected by different insertion sites. METHODS: The Newcastle shoulder model was used to investigate the biomechanics of these 2 tendon transfers. Computed tomography data sets from 10 healthy subjects were used to customize the model, and virtual LD and LT transfers were performed on supraspinatus, infraspinatus, and teres minor insertion sites. Muscle moment arms and lengths were computed for abduction, forward flexion, and external rotation. RESULTS: The LT yields greater abduction moment arms compared with the LD when it is transferred to the native supraspinatus and infraspinatus insertion sites. However, they become adductors when transferred to the native teres minor insertion. Both muscles show strong external rotation moment arms, except for the LT with a supraspinatus insertion. Resting muscle strains were 0.21 (±0.03), 0.12 (±0.02), and 0.06 (±0.03) for the LD and 0.70 (±0.15), 0.61 (±0.13), and 0.58 (±0.13) for the LT for the supraspinatus, infraspinatus, and teres minor insertions, respectively. CONCLUSIONS: LT provided better abduction and external rotation moment arms when transferred to the infraspinatus insertion. LD performed better when transferred to the supraspinatus insertion. Overall, LT transfer showed a biomechanical advantage compared with LD transfer because of stronger abduction moment arms. However, significantly larger muscle strains after LT transfer necessitate a tendon allograft to prevent muscle overtensioning.

Comparative cost-effectiveness analysis of the subacromial spacer for irreparable and massive rotator cuff tears.

PURPOSE: There is ongoing debate regarding the optimal surgical treatment of irreparable rotator cuff tears (IRCT). This study aimed to assess within the Italian health care system the cost-effectiveness of subacromial spacer as a treatment modality for patients with IRCT. METHODS: An expected-value decision analysis was created comparing costs and outcomes of patients undergoing arthroscopic subacromial spacer implantation, rotator cuff repair (RCR), total shoulder arthroplasty, and conservative treatment for IRCTs. A broad literature search provided input data to extrapolate and inform treatment success and failure rates, costs, and health utility states for these outcomes. The primary outcome assessed was an incremental cost-effectiveness ratio (ICER) of subacromial spacer implantation versus shoulder arthroplasty, RCR, and conservative treatment. RESULTS: Subacromial spacer is favorable over both arthroscopic partial repair and shoulder arthroplasty since it costs less than both options and increases effectiveness by 0.06 and 0.10 quality-adjusted life years (QALYs), respectively. While conservative treatment is the least costly management strategy, subacromial spacer results in a gain of 0.05 QALYs for the additional cost of 522 €, resulting in an ICER of 10,440 €/QALY gain, which is below the standard willingness to pay ratio of $50,000 USD. Strategies with an ICER of less than 50,000 USD are considered to be cost-effective. CONCLUSIONS: Based on the available evidence and reasonably conservative assumptions, subacromial spacer is likely to provide a safe, effective, and cost-effective option for patients with massive IRCTs. Furthermore, this cost-effectiveness analysis may ultimately serve as a guide for development of health care system and insurer policy as well as clinical practice.

Biomechanical evaluation of an arthroscopic transosseous repair as a revision option for failed rotator cuff surgery.

BACKGROUND: The number of revision rotator cuff cases is increasing. The literature is lacking guidance or biomechanical evaluation for fixation strength in a revision case scenario. Therefore, the aim of the study was to provide biomechanical data investigating primary fixation strength of a transosseous technique after anchor pullout failure of a single row reconstruction. It was hypothesized that an arthroscopic transosseous repair system as a procedure for rotator cuff revisions is providing equivalent stability compared to a primary single row suture anchor fixation due to change of fixation site. METHODS: Eight matched pairs (n = 16) of fresh frozen human shoulders were tested. The paired specimen shoulders were randomly divided into two repair groups (A single row and B primary transosseous repair). The potted specimens were mounted onto the Servohydraulic test system. Both groups were tested under cyclic loading followed by load to failure testing. Suture anchor repair shoulders (group A) that were tested to failure underwent a revision transosseous repair and were subsequently tested again using the same setup and protocol (group C). RESULTS: The mean native footprint areas did not show a significant difference between groups. The reconstructed footprint area showed a significantly greater coverage in favor of the transosseous repair. Ultimate load to failure of reconstructions with the primary anchor fixation (344.73 N ± 63.19) and the primary transosseous device (375.36 N ± 70.27) was not significantly higher compared to the revision repair (332.19 N ± 119.01 p = 0.45, p = 0.53). CONCLUSION: The tested transosseous anchor device is a suitable option to widely used suture anchors, providing equivalent fixation properties even in a revision case scenario. LEVEL OF EVIDENCE: Basic Science Study, Biomechanics.

Is there a difference in clinical outcomes and repair integrity between arthroscopic single-row versus transosseous (anchorless) fixation? A retrospective comparative study.

BACKGROUND: Few studies have investigated clinical and structural outcomes after transosseous (TO) repair. The purpose of this study was to compare structural and clinical outcomes of rotator cuff tear, repaired arthroscopically, with a single row (SR) or transossoeus (TO) anchorless technique. METHODS: 96 patients who underwent an arthroscopic repair for superior or posterosuperior rotator cuff tear using TO (n:54) or a SR (n:42) were retrospectively enrolled in this study after evaluation of clinical and surgical notes. Functional evaluation was performed with the adjusted Constant score, and American Shoulder and Elbow Surgeons (ASES) score. Postoperative cuff integrity was determined through MRI study. RESULTS: Patients were recalled after a minimum follow-up of two years. All the patients were available for the study. In the SR group the Constant rating system showed a significant improvement from a preoperative average rating of 44.8 to an average of 85.7. In the group of TO repair the Constant rating system showed a significant improvement from a preoperative average of 46.1 to an average of 87.6 postoperatively. According to ASES index scores, the average total score improved from 42.8 to 92.0 in the anchor group and from 40.4 to 94.6 in the TO group. There was no statistical difference between the two groups about clinical outcomes. Postoperative MRI revealed no differences in term of complete re-tears between the two techniques. In the SR group at MRI we observe significant more cases of rotator cuff with a Sugaya type III healing. CONCLUSIONS: Arthroscopic rotator cuff repair yielded successful clinical outcomes using SR and TO technique. However using the TO technique we saw less type 3 Sugaya readings on MRI suggesting a possible benefit with TO repair. LEVEL OF EVIDENCE II: Retrospective study.