Currently, the consensus regarding subscapularis tendon repair during a reverse total shoulder arthroplasty (rTSA) is to do so if it is possible. Repair is thought to decrease the risk of dislocation and improve internal rotation but may also increase stiffness and improvement in internal rotation may be of subclinical benefit. Aim is to retrospectively evaluate the outcomes of rTSA, with or without a subscapularis tendon repair. We completed a retrospective review of 51 participants (25 without and 26 with subscapularis repair) who received rTSR by a single-surgeon using a single-implant. Three patient reported outcome measures (PROM) were assessed pre-operatively and post-operative at twelve months, as well as range of movement (ROM) and plain radiographs. Statistical analysis utilized unpaired t tests for parametric variables and Mann-Whitney U test for nonparametric variables. External Rotation ROM pre-operatively was the only variable with a significance difference (p=0.02) with the subscapularis tendon repaired group having a greater range. Pre- and post-operative abduction (p=0.72 & 0.58), forward flexion (p=0.67 & 0.34), ASES (p=0.0.06 & 0.78), Oxford (p=0.0.27 & 0.73) and post-operative external rotation (p=0.17). Greater external rotation ROM pre-operatively may be indicative of the ability to repair the subscapularis tendon intra-operatively. However, repair does not seem to improve clinical outcome at 12 months. There was no difference of the PROMs and AROMs between the subscapularis repaired and not repaired groups for any of the variables at the pre-operative or 12 month post operative with the exception of the external rotation ROM pre-operatively. We can conclude that from PROM or AROM perspective there is no difference if the tendon is repaired or not in a rTSR and indeed the patients without the repair may have improved outcomes at 12 months

The Latarjet procedure is a well described method to stabilize anterior shoulder instability. There are concerns of high complication rates, one of these being a painful shoulder without instability due to screw irritation. The arthroscopic changes in the shoulder at time of screw removal compared to those pre-Latarjet have not been described in the literature. We conducted a retrospective review of arthroscopic videos between 2015 and 2022 of 17 patients at the time of their Latarjet screw removal and where available (n=13) compared them to arthroscopic findings at time of index Latarjet. Instability was an exclusion criterion. X-rays prior to screw removal were assessed independently by two observers blinded to patient details for lysis of the graft. Arthroscopic assessment of the anatomy and pathological changes were made by two shoulder surgeons via mutual consensus. An intraclass correlation coefficient (ICC) was analyzed as a measure for the inter-observer reliability for the radiographs. Our cohort had an average age of 21.5±7.7 years and an average period of 16.2±13.1 months between pre- and post-arthroscopy. At screw removal all patients had an inflamed subscapularis muscle with 88% associated musculotendinous tears and 59% had a pathological posterior labrum. Worsening in the condition of subscapularis muscle (93%), humeral (31%) and glenoid (31%) cartilage was found when compared to pre-Latarjet arthroscopes. Three failures of capsular repair were seen, two of these when only one anchor was used. X-ray review demonstrated 79% of patients had graft lysis. Excellent inter-rater reliability was observed with an ICC value of 0.82. Our results show a high rate of pathological change in the subscapularis muscle, glenoid labrum and articular cartilage in the stable but painful Latarjet. 79% of patients had graft lysis with prominent screws on X-ray

Shoulder arthroplasty procedures continue to increase in prevalence and controversy still remains about the optimal method to manage the subscapularis. Scalise et al. performed an analysis of 20 osteotomies and 15 tenotomy procedures, and found the tenotomy group had a higher rate of abnormal subscapularis tendons on ultrasound examination. There was one tendon rupture in the subscapularis tenotomy group and no ruptures in the osteotomy group. Jandhyala et al. retrospectively examined 26 lesser tuberosity osteotomies and 10 subscapularis tenotomies for arthroplasty, and their study demonstrated a significant improvement in the belly press test for the osteotomy group. Lapner et al. performed a randomised controlled trial assigning patients to either a lesser tuberosity osteotomy or a subscapularis peel procedure. They evaluated 36 osteotomies and 37 subscapularis peels. The outcomes evaluated were Dynamometer internal rotation strength, the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score and American Shoulder and Elbow Surgeons (ASES) score, and in a subsequent paper they evaluated the healing rates and Goutallier grade. Their studies illustrated no difference in the internal rotation strength between groups. Both groups significantly improved WOOS and ASES scores postoperatively, but the difference was not significant between groups. Goutallier grade increased significantly in both groups, but there was no significant difference between the groups. Overall, the different approaches have not demonstrated a meaningful clinical difference. Further studies are needed to help understand issues leading to subscapularis complications after arthroplasty

Introduction & Background. Clinical outcome after reverse total shoulder arthroplasty (RTSA) can be influenced by technical and implant-related factors, so the purpose of this study was to investigate whether individualizing humeral retroversion and subscapularis repair affect the clinical outcomes after RTSA. Material & Method. Authors retrospectively analyzed the prospectively collected data from 80 patients who underwent RTSA from January 2007 to January 2015 using same implant (Biomet Comprehensive. ®. Reverse Shoulder System, Warsaw, Indiana). The mean follow up was 23.3 ± 1.7 (range, 12 ∼ 70) months. The retroversion of humeral component was decided according to native version estimated using shoulder CT in Group I (n=52), and fixed in 20° retroversion in Group II (n=28). Group I was subdivided into Group Ia (n=21, mean 19.3°), less than 20° of retroversion, and Group Ib (n=31, mean 31.9°), more than 20°. Intraoperative tenotomized subscapularis was repaired in 40 patients in Group I, and could not be repaired due to massive tear including subscapularis in remaining 12 patients. Clinical outcomes were evaluated with range of motion (ROM) and several clinical outcome scores. Results. Group I showed significantly better ROM and clinical scores compared to Group II at the final follow up (all p < 0.05). There were no significant differences in ROM and clinical scores between Group Ia and Ib. Group Ia showed better ROM and pain VAS than Group II (all p < 0.05), and Group Ib also demonstrated significantly better ROM and clinical outcome scores than Group II (all p < 0.05). With respect to subscapularis repair, there were no differences in ROM and clinical scores between two groups. No complications such as infection or dislocation were detected according to subscapularis repair. Conclusion. Individualizing humeral retroversion can obtain superior clinical outcomes than fixed 20° retroversion. Subscapularis repair would not be essential for the better clinical outcome in patients with the lateralized RTSA

Background. Long term success of any shoulder joint reconstruction procedure involving subscapularis attachment take down is dictated by the way one chooses to release and repair/reconstruct the subscapularis insertion. There are several methods that were reported in the literature without any preset guidelines which are easily reproducible. Methods. 5 specimens of fresh cadaver shoulder joints dissected and the subscapularis footprint insertion involving the tendon and muscle exposed. We intend to preserve subscapularis tendon footprint along with the lesser tuberosity by performing the footprint osteotomy fashioned step wise in the following manner. Results. It has two vertical components (sagittal and coronal plane osteotomies) and one horizontal component (distal osteotomy at musculo tendinous junction level). Figure 1: demonstrating the three step cuts in the dry bone of proximal humerus with three different ostetomes to mark the plain of osteotomies in the lesser tuberosity. Step-1: Medial wall ridge of the inter-tubercular sulcus serves as landmark for sagittal component. The depth of sagittal component is just 5 – 10mm and its length extending from articular margin proximally and distally up to musculo tendinous junction, measuring approximately 15–20mm. Step-2: Coronal plane osteotomy is in line with and parallel to undersurface of subscapularis tendon adjacent to the articular margin and connecting sagittal component and measured 10–15mm approximately. Figure 2: demonstrating the two cuts / osteotomies to mark the sagittal and coronal components of the subscapularis foot print osteotomy in the lesser tuberosity of a fresh cadaver. Step-3: The horizontal component (distal osteotomy at musculo tendinous junction level is 5–10 mm in width, connects the two vertical components, thus completing the footprint osteotomy. Discussion. Subscapularis reattachment plays a pivotal role in the shoulder joint reconstruction procedures especially total joint arthroplasty. Subscapularis take down either by tenotomy or by periosteal elevation from lesser tuberosity followed by repair carries a risk of retraction and poor healing and early failure. Footprint osteotomy as a thin sliver of cortical bone instead of these above described three steps with the attached tendon carries a risk of fragmentation of the bone sliver along with lack of rotation control on the repair. The necessity for doing such a three step osteotomy procedure which results in a wedge shaped bone tendon foot print construct, we believe is of paramount importance for a successful reconstruction. Figure 3: demonstrating the marking sutures passed into the bone tendon construct comprising of lesser tuberosity and subscapularis for effective foot print reconstruction in a fresh cadaver. Conclusions. This three step footprint osteotomy of the Subscapularis tendon offers a stable construct which is easy to reproduce with better healing potential. For figures, please contact authors directly

There is a large and growing population of patients with shoulder arthritis that are over 70 years old. Many of these patients live alone and sling immobilization after shoulder arthroplasty is problematic. Other than improved internal rotation, there are limited benefits of anatomic shoulder arthroplasty compared to reverse arthroplasty. Anatomic arthroplasty is associated with longer OR time, longer recovery with need for assistance to allow the subscapularis to heal, and more challenging glenoid exposure. The reverse arthroplasty is a faster operation without the need for subscapularis healing and the sphere provides a more forgiving implant position. Additional benefits of reverse arthroplasty include better ability to manage glenoid bone loss and joint subluxation. Data from the Australian Orthopaedic Association National Joint Replacement Registry shows that within the first year of surgery the rate of revision of anatomic shoulder arthroplasty is less than reverse arthroplasty. However, after one year, the overall revision rate of reverse arthroplasty is less than anatomic shoulder arthroplasty. Therefore, increased technical difficulty of anatomic shoulder arthroplasty together with concerns of subscapularis insufficiency, glenoid loosening, and lack of strong evidence of superiority do not warrant changing from reverse for patients over 70 years old

It is undetermined which factors predict return to work following arthroscopic rotator cuff repair. We aimed to identify which factors predicted return to work at any level, and return to pre-injury levels of work 6 months post-arthroscopic rotator cuff repair. Multiple logistic regression analysis of prospectively collected demographic, pre-injury, preoperative, and intraoperative data from 1502 consecutive primary arthroscopic rotator cuff repairs, performed by a single surgeon, was performed to identify independent predictors of return to work, and return to pre-injury levels of work respectively, 6 months post-surgery. Six months post-rotator cuff repair, 76% of patients returned to work (RTW), and 40% returned to pre-injury levels of work (Full-RTW). RTW at 6 months was likely if patients were still working after their injuries, but prior to surgery (Wald statistic [W]=55, p<0.0001), were stronger in internal rotation preoperatively (W=8, p=0.004), had full-thickness tears (W=9, p=0.002), and were female (W=5, p=0.030). Patients who achieved Full-RTW were likely to have worked less strenuously pre-injury (W=173, p<0.0001), worked more strenuously post-injury but pre-surgery (W=22, p<0.0001), had greater behind-the-back lift-off strength preoperatively (W=8, p=0.004), and had less passive external rotation range of motion preoperatively (W=5, p=0.034). Patients who were still working post-injury, but pre-surgery were 1.6-times more likely to RTW than patients who were not (p<0.0001). Patients who nominated their pre-injury level of work as “light” were 11-times more likely to achieve Full-RTW than those who nominated “strenuous” (p<0.0001). Six months post-rotator cuff repair, a higher patient-rated post-injury, but pre-surgery level of work was the strongest predictor of RTW. A lower patient-rated pre-injury level of work was the strongest predictor of Full-RTW. Greater preoperative subscapularis strength independently predicted both RTW, and Full-RTW

Introduction:. The subscapularis muscle experiences significant strain as it accommodates common movements of the shoulder. Little is known about what happens with this obligatory strain once the subscapularis insertion is disrupted and repaired in the course of shoulder arthroplasty. Subscapularis failure is a serious known complication after shoulder arthroplasty. It is not known what the effect of increasing the thickness of the shoulder head will have on subscapularis strain. It is our hypothesis that the use of large or expanded humeral heads during shoulder replacement will cause increased tension in the repaired subscapularis. The primary purpose of this study was to identify the optimal manner to perform a passive range of motion (PROM) program without invoking a significant increase in strain in the repaired subscapularis. The secondary purpose was to determine the impact of varying the thickness of the humeral head on subscapularis strain using the same PROM protocol. Methods:. Eight fresh-frozen, forequarter cadaver (four female, four male) specimens were obtained following IRB approval. An extended deltopectoral incision was performed so that the subscapularis insertion site could be well visualized. PROM exercises with the following motions were evaluated: external rotation, abduction, flexion and scaption. An optical motion analysis system was used to measure strain in the subscapularis. The same measurement protocol was repeated after performing a subscapularis osteotomy and after placement of an anatomic hemiarthroplasty of three different thicknesses (short, tall, expanded). Results:. A decrease in joint laxity (less strain but more tension on the subscapularis) was observed in abduction, external rotation, and forward flexion, following implantation of the shoulder arthroplasty components. For abduction and forward flexion, we observed a trend of decreasing laxity with increasing humeral head component thickness. For external rotation, all components displayed a similar reduction in joint laxity. With the short humeral head, strain was similar to native joint with passive scaption and flexion but not with external rotation or abduction. Discussion:. The PROM that tends to minimize tension on the subscapularis is forward flexion and scaption whereas external rotation and abduction will stress the subscapularis repair. Therefore passive forward flexion or scaption do not need to be limited but clearly external rotation should have passive limits and abduction should probably be avoided. The subscapularis muscle is under greater preload tension after shoulder joint arthroplasty. Even the short head size humeral component demonstrated decreased laxity compared to the intact joint. This suggests that even the shortest head size available may not be anatomical and perhaps a thinner humeral head size would be more representative of the normal anatomy

Shoulder arthroplasty procedures continue to increase in prevalence, and controversy still remains about the optimal method to manage the subscapularis. Scalise et al. performed an analysis of 20 osteotomies and 15 tenotomy procedures, and found the tenotomy group had a higher rate of abnormal subscapularis tendons on ultrasound examination. There was one tendon rupture in the subscapularis tenotomy group and no ruptures in the osteotomy group. Jandhyala et al. retrospectively examined 26 lesser tuberosity osteotomies and 10 subscapularis tenotomies for arthroplasty, and their study demonstrated a significant improvement in the belly press test for the osteotomy group. Lapner et al. performed a randomised controlled trial assigning patient to either a lesser tuberosity osteotomy or a subscapularis peel procedure. They evaluated 36 osteotomies and 37 subscapularis peels. The outcomes evaluated were Dynamometer internal rotation strength, the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score and American Shoulder and Elbow Surgeons (ASES) score, and in a subsequent paper they evaluated the healing rates and Goutallier grade. Their studies illustrated no difference in the internal rotation strength between groups. Both groups significantly improved WOOS and ASES scores post-operatively, but the difference was not significant between groups. Goutallier grade increased significantly in both groups, but there was no significant difference between the groups. Overall, the different approaches have not demonstrated a meaningful clinical difference. Further studies are needed to help understand issues leading to subscapularis complications after arthroplasty

Subscapularis function following Total shoulder joint replacement has been a concern in recent literature. It has been postulated that lesser tuberosity osteotomy approach may have better Subscapularis function than transtendonous approach. To assess whether lesser tuberosity osteotomy vs. subscapularis tenotomy is better for post-operative function of subscapularis in total shoulder replacements done by a single surgeon in a District general hospital. 117 shoulder replacements performed by the senior author (TH) at Waikato district general hospital between years January 2002 to January 2010 were reviewed retrospectively. Revision replacement, inverse shoulder replacement & acute traumatic hemiarthroplasty were excluded. Patients with previous rotator cuff problems, previous surgery to subscapularis, rheumatoid arthritis and post-trauma sequelae were also excluded from the study. Inclusion criteria were normal subscapularis function and intact subscapularis on MRI pre-operatively. 41 shoulders were eligible to participate in study of which 1 pt died (bilateral TSR), 1 pt unfit to participate due to cervical disc problems. Of remaining 38 shoulders 11 shoulders had transtendonous and 27 shoulders had lesser tuberosity osteotomy approach. 37 shoulders were reviewed clinically for range of motion of the shoulder and subscapularis strength. Range of motion and subscapularis strength was significantly higher in the osteotomy group. All osteotomies were united on axillary radiograph. Lesser tuberosity osteotomy approach result in better subscapularis function than transtendonous approach

Hemi shoulder arthroplasty is a rather successful procedure although revision surgery due to secondary glenoid erosion is reported in more than 25%. The downside of common shoulder arthroplasty is that in a deltopectoral approach the subscapularis tendon needs to be detached for exposure of the humeral head. Refixation of subscapularis tendon is associated with a retear rate of 4%, furthermore with progressing fatty muscle infiltration and loss of function. In case of revision surgery a second subscapularis tendon detachment is even more associated with worse function. Thus, arthroscopic humeral head resurfacing is an expedient alternative for minimal invasive humeral head arthroplasty without compromising subscapularis function. The purpose of this study was to report first clinical and subjective results after arthroscopic-assisted resurfacing of the humeral head. For this prospective case series, 24 patients (7 females, 17 males; mean age 59 years, range 42–73 years) undergoing arthroscopic-assisted partial shoulder resurfacing with the partial eclipse prosthesis were included in the study. Clinical conditions and subjective assessments were evaluated before surgery and annually thereafter using the Constant score (CS), active range of motion (ROM), visual analog scale (VAS) for pain, and the American Shoulder and Elbow Surgeons scale (ASES). Radiological outcomes and major complications were monitored. The mean CS for all patients improved significantly from 51 points preoperatively to 83 points 12 months after surgery (p=0.005). Trends towards increasing ROMs were detected. Subjective scores significantly improved from baseline to the 1-year follow-up (VAS: from 6.4 to 2.5, p=0.010; ASES: from 47 to 76, p=0.026). The majority of patients (88%) stated that they would undergo the procedure again. Revisions were indicated in 17% due to progression of osteoarthritis. Arthroscopic-assisted partial humeral head resurfacing as a minimal invasive procedure with the advantages of bone stock preservation and intact subscapularis tendon allowed immediate postoperative active mobilization and provided significant improvements in subjective outcome. In case of revision surgery a primary situation was encountered with postoperative results comparable to primary arthroplasty

The standard approach is through the deltopectoral interval. Among patients with prior incisions, one makes every effort to either utilise the old incision or to incorporate it into a longer incision that will allow one to approach the deltopectoral interval and retract the deltoid laterally. The deltopectoral interval is most easily developed just distal to the clavicle, where there is a natural infraclavicular triangle of fat that separates the deltoid and pectoralis major muscles even in very scarred or stiff shoulders. Typically, the deltoid is retracted laterally leaving the cephalic vein on the medial aspect of the exposure. The anterior border of the deltoid is mobilised from the clavicle to its insertion on the humerus. The anterior portion of the deltoid insertion together with the more distal periosteum of the humerus may be elevated slightly. The next step is to identify the plane between the conjoined tendon group and the subscapularis muscle. Dissection in this area must be done very carefully due to the close proximity of the neurovascular group, the axillary nerve, and the musculocutaneous nerve. Scar is then released from around the base of the coracoid. The subacromial space is freed of scar and the shoulder is examined for range of motion. Particularly among patients with prior rotator cuff surgery, there may be severe scarring in the subacromial space. Internal rotation of the arm with dissection between the remaining rotator cuff and deltoid is critical to develop this plane. If external rotation is less than 30 degrees, one can consider incising the subscapularis off bone rather than through its tendinous substance. For every 1 cm that the subscapularis is advanced medially, one gains approximately 20 to 30 degrees of external rotation. The rotator interval between the subscapularis and supraspinatus is then incised. This release is then continued inferiorly to incise the inferior shoulder capsule from the neck of the humerus. This is performed by proceeding from anterior to posterior with progressive external rotation of the humerus staying directly on the bone with electrocautery and great care to protect the axillary nerve. The key for glenoid exposure as well as improvement in motion is deltoid mobilization, a large inferior capsular release, aggressive humeral head cut and osteophyte removal

Subscapularis tenotomy (SST) has been the preferred approach for shoulder arthroplasty for decades but recent controversy has propelled lesser tuberosity osteotomy (LTO) as a potential alternative. Early work by Gerber suggested improved healing and better outcomes with LTO although subscapularis muscular atrophy occurred in this group as well with unknown long-term implications. However, we previously performed a biomechanical study showing that some of the poor results following tenotomy may have been due to historic non-anatomic repair techniques. Surgical technique is critical to allow anatomic healing – this is true of both SST or LTO techniques. A recent meta-analysis of biomechanical cadaveric studies showed that LTO was stronger to SST at “time-zero” with respect to load to failure but there were no significant differences in cyclic displacement. A recent study evaluated neurodiagnostic, functional, and radiographic outcomes in 30 patients with shoulder arthroplasty who had SST. The authors found that the EMG findings were normal in 15 patients but abnormal in the other 15 and that these abnormalities occurred in 5 muscle groups (not just the subscapularis). In another study, patient outcomes were inferior in those patients who had documented subscapularis dysfunction following SST compared to patients who had LTO (none of whom had subscap dysfunction). The literature is not clear, however, on ultimate outcomes based on subscapularis dysfunction post-arthroplasty with some studies showing no difference and others showing significant differences

Total shoulder arthroplasty is becoming increasingly common. A biceps tenodesis or tenotomy has become a routine part of the operation. There are several advantages to a tenodesis or tenotomy. First, the long head of the biceps tendon is routinely pathologic. One study has shown that there are differences in gene expression and mechanical properties in the long head of the biceps tendon in the setting of glenohumeral joint arthritis. Clinically, we often see inflammation, tearing, adhesions, or other pathology. Second, it is largely accepted that the long head of the biceps tendon has minimal function at the shoulder. The biceps muscle primarily functions at the elbow. Therefore, there is little downside to performing a tenodesis if there is a chance of it generating pain after surgery. Another major reason to perform a tenodesis or a tenotomy is that the technique of total shoulder arthroplasty requires a subscapularis takedown or lesser tuberosity osteotomy. The ligaments and tendon associated with the subscapularis contribute to the stability of the biceps tendon and after subscapularis takedown, it is unlikely that the tendon would remain reduced in the groove. In addition, it is part of a technique to incise and release the rotator interval, additionally creating scarring and/or instability associated with the biceps tendon. Given those reasons, this is a very common and reasonable routine part of the procedure of total shoulder arthroplasty

Introduction. Reverse shoulder arthroplasty (rTSA) increases the deltoid abductor moment arm length to facilitate the restoration of arm elevation; however, rTSA is less effective at restoring external rotation. This analysis compares the muscle moment arms associated with two designs of rTSA humeral trays during two motions: abduction and internal/external rotation to evaluate the null hypothesis that offsetting the humerus in the posterior/superior direction will not impact muscle moment arms. Methods. A 3-D computer model simulated abduction and internal/external rotation for the normal shoulder, the non-offset reverse shoulder, and the posterior/superior offset reverse shoulder. Four muscles were modeled as 3 lines from origin to insertion. Both offset and non-offset reverse shoulders were implanted at the same location along the inferior glenoid rim of the scapula in 20° of humeral retroversion. Abductor moment arms were calculated for each muscle from 0° to 140° humeral abduction in the scapular plan using a 1.8: 1 scapular rhythm. Rotation moment arms were calculated for each muscle from 30° internal to 60° external rotation with the arm in 30° abduction. Results. During abduction with the normal shoulder, the subscapularis and infraspinatus act as abductors throughout the range of motion and the teres minor converts from an adductor to abductor at 60°. In the non-offset reverse shoulder, the subscapularis converts from an adductor to abductor at 82°, the infraspinatus converts at 68°, and the teres minor converts at 135°. Because the offset humeral tray shifts the humerus superiorly relative to the non-offset tray, each muscle converts from an adductor to abductor earlier in abduction, where the subscapularis converts at 62°, the infraspinatus converts at 43°, and the teres minor converts at 110°. During rotation (Figures 1–3), both the offset and non-offset reverse shoulders decrease the internal rotation capability of the subscapularis and teres major but increase the external rotation capability of the infraspinatus and teres minor relative to the normal shoulder. Because the offset tray shifts the humerus posteriorly, the internal rotation capability of the subscapularis and teres major is decreased by 7.1 and 9.5 mm while the external rotation capability of the infraspinatus and teres minor is increased by 8.6 and 7.8 mm, respectively. Discussion and Conclusions. Changing humeral position using an offset humeral tray modified the function of each muscle. In abduction, the offset tray caused each muscle to convert from adductors to abductors earlier. Improved abduction capability limits each muscle's antagonistic behavior with the deltoid, potentially reducing the deltoid force required to elevate the arm. In rotation, the offset tray caused the posterior shoulder muscles to be more effective external rotators. Improved external rotation capability is important for patients with external rotation deficiency; as external rotation is required for many activities of daily living, increasing the rotator moment arm lengths of the only two external rotators is advantageous to restore function. Therefore, we reject the null hypothesis and conclude the offset humeral tray does impact muscle moment arms with rTSA. Future work should evaluate the clinical significance of these observed changes in muscle moment arms

Introduction. Posterior glenoid wear is common in glenohumeral osteoarthritis. Tightening of the subscapularis causes posterior humeral head subluxation and a posterior load concentration on the glenoid. The reduced contact area causes glenoid wear and potentially posterior instability. To correct posterior wear and restore glenoid version, surgeons may eccentrically ream the anterior glenoid to re-center the humeral head. However, eccentric reaming undermines prosthesis support by removing unworn anterior glenoid bone, compromises cement fixation by increasing the likelihood of peg perforation, and medializes the joint line which has implications on joint stability. To conserve bone and preserve the joint line when correcting glenoid version, manufacturers have developed posterior augment glenoids. This study quantifies the change in rotator cuff muscle length (relative to a nonworn/normal shoulder) resulting from three sizes of posterior glenoid defects using 2 different glenoids/reaming methods: 1) eccentric reaming using a standard (nonaugmented) glenoid and 2) off-axis reaming using an 8, 12, and 16° posterior augment glenoid. Methods. A 3-D computer model was developed in Unigraphics (Siemens, Inc) to simulate internal/external rotation and quantify rotator cuff muscle length when correcting glenoid version in three sizes of posterior glenoid defects using posterior augmented and non-augmented glenoid implants. Each glenoid was implanted in a 3-D digitized scapula and humerus (Pacific Research, Inc); 3 sizes (small, medium, and large) of posterior glenoid defects were created in the scapula by posteriorly shifting the humeral head and medially translating the humeral head into the scapula in 1.5 mm increments. Five muscles were simulated as three lines from origin to insertion except for the subscapularis which was wrapped. After simulated implantation in each size glenoid defect, the humerus was internally/externally rotated from 0 to 40° with the humerus at the side. Muscle lengths were measured as the average length of the three lines simulating each muscle at each degree of rotation and compared to that at the corresponding arm position for the normal shoulder without defect to quantify the percentage change in muscle length for each configuration. Results. As depicted in Figures 1–3, muscle shortening was observed for each muscle for each size defect. For each size uncorrected defect, the subscapularis was observed to wrap around the anterior glenoid rim during internal rotation and with the arm at neutral; both eccentric successfully re-centered the humeral head and eliminate subscapularis wrapping around the anterior glenoid rim. However, eccentric reaming was also found to medialize the joint line and resulted in approximately 1.5, 2.5, and 3.5% additional muscle shortening for each muscle relative to the augmented glenoid in each size defect, respectively. Discussion and Conclusions. This study demonstrates that posterior glenoid wear medializes the joint line and results in rotator cuff muscle shortening. Augmented glenoids offer the potential to better restore the joint line and minimize muscle shortening, particularly when used in large glenoid defects. Future work should investigate the clinical significance of 1.5–3.5% of muscle shortening and evaluate the functional impact of subscapularis wrapping around the anterior glenoid rim

Purpose. Controversy exists regarding the optimal technique of subscapularis mobilization during shoulder arthroplasty. The purpose of this multicentre randomized double-blind study was to compare the functional outcomes and healing rates of the lesser tuberosity osteotomy (LTO) to the subscapularis tenotomy (ST). Method. Patients undergoing shoulder arthroplasty were randomized to receive either a LTO or ST. The primary outcome was to compare subscapularis strength, as measured by an electronic hand-held dynamometer at 12 months. Secondary outcomes included range of motion, WOOS, Constant and ASES scores. A sample size calculation determined that 80 patients provided 80% power with a 50% effect size to detect a significant difference between groups. Results. Baseline demographic data did not differ between groups including age (p=0.69), sex (p=0.77), affected side (p=0.59) and arthroplasty type (hemiarthroplasty or total, p=0.77). Strength comparison between groups revealed no statistical differences at any time interval (p=0.744, baseline, p=0.449, 3 month, p=0.203, 6 months, 12 months, p=0.45). Statistically significant improvements occurred in both groups from baseline to 12 month time points in all clinical outcome scores (p<0.0001). Conclusion. No statistically significant differences in primary or secondary outcomes were identified between the LTO and ST. This trial does not demonstrate any clear advantage of one subscapularis mobilization technique over the other

Aim. Two different techniques to release subscapularis during total shoulder replacement (TSR) have been described (tenotomy and osteotomy) with no consensus as to which is superior. In this study we review the clinical outcomes of a sequential series of patients in whom a TSR for primary osteoarthritis had been performed using either technique at our institution. Subscapularis function was tested using a new graded belly press test, a modification of the traditional belly press test which is described for the first time here. Methods. All patients who underwent surgery at our institution between January 2002 and January 2010 and met the eligibility criteria, were included for analysis. Subscapularis function was assessed post-operatively using a range of functional assessments including; a graded belly press test, lift off test, and an assessment of each patient's range of movement. Results. A total of 36 shoulders in 36 patients were included, ten underwent subscapularis tenotomy and 26 underwent osteotomy of the lesser tuberosity. Patients who had undergone osteotomy of the lesser tuberosity had a more favourable outcome overall. They demonstrated a significantly better grade (grade 1) of the belly press test compared with the tenotomy group (p=0.026) and a trend towards a better range of movement although no statistical significance was shown. All patients (osteotomy and tenotomy) with a grade 1 belly press test had a better clinical outcome with data demonstrating statistical significance. Conclusion. Our results indicate that in this single surgeon sequential series of patients who underwent osteotomy of the lesser tuberosity during TSR for OA had a better functional outcome than those who underwent subscapularis tenotomy. While our modification of the belly press test may require further validation we would suggest it may be a more useful indicator of subscapularis function in future studies

The cellular mechanisms of tendinopathy remain unclear, particularly with respect to the role of inflammation in early disease. We have previously identified increased levels of inflammatory cytokines in an early human model of tendinopathy and sought to extend these studies to the cellular analysis of tissue. Purpose. To characterise inflammatory cell subtypes in early human tendinopathy we explored the phenotype and quantification of inflammatory cells in torn and control tendon samples. Design. Controlled laboratory study. Methods. Torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from twenty patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from ten patients undergoing arthroscopic stabilisation surgery. Tendon biopsies were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD206), T cells (CD3), mast cells (Mast cell tryptase) and vascular endothelium (CD34). Results. Subscapularis tendon biopsies obtained from patients with torn supraspinatus tendon exhibited significantly greater macrophage, mast cell and T cell expression compared to either torn supraspinatus samples or control subscapularis derived tissue (p< 0.01). Inflammatory cell infiltrate correlated inversely (r=0.5, p< 0.01) with rotator cuff tear size, with larger tears correlating with a marked reduction in all cell lineages. There was a modest but significant correlation between mast cells and CD 34 expression (r= 0.4, p< 0.01) in pre-rupture subscapularis tendon. Conclusion. We provide evidence for an inflammatory cell infiltrate in early mild/moderate human supraspinatus tendinopathy. In particular, we demonstrate significant infiltration of mast cells and macrophages suggesting a role for innate immune pathways in the events that mediate early tendinopathy. Further mechanistic studies to evaluate the net contribution and hence therapeutic utlity of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early tendinopathy

When compared to magnetic resonance imaging (MRI), ultrasound (US) performed by experienced users is an inexpensive tool that has good sensitivity and specificity for diagnosing rotator cuff (RC) tears. However, many practitioners are now utilizing in-office US with little to no formal training as an adjunct to clinical evaluation in the management of RC pathology. The purpose of our study was to determine if US without formal training is effective in managing patients with a suspected RC tear. This was a single centre prospective observational study. Five fellowship-trained surgeons each examined 50 participants referred for a suspected RC tear (n= 250). Patients were screened prior to the consultation and were included if ≥ 40 years old, had an MRI of their affected shoulder, had failed conservative treatment of at least 6 months, and had ongoing pain and disability. Patients were excluded if they had glenohumeral instability, evidence of major joint trauma, or osteonecrosis. After routine clinical exam, surgeons recorded their treatment plan (“No Surgery”, “Uncertain”, or “Surgery”). Surgeons then performed an in-office diagnostic US followed by an MRI and documented their treatment plan after each imaging study. Interrater reliability was analyzed using a kappa statistic to compare clinical to ultrasound findings and ultrasound findings to MRI, normal and abnormal categorization of biceps, supraspinatus, and subscapularis. Following clinical assessment, the treatment plan was recorded as “No Surgery” in 90 (36%), “Uncertain” in 96 (39%) of cases, “Surgery” in 61 (25%) cases, and incomplete in 3 (2%). In-office US allowed resolution of 68 (71%) of uncertain cases with 227 (88%) of patients having a definitive treatment plan. No patients in the “No Surgery” group had a change in treatment plan. After MRI, 16 (6%) patients in the “No Surgery” crossed-over to the “Surgery” group after identification of full-thickness tears, larger than expected tears or alternate pathology (e.g., labral tear). The combination of clinical examination and in-office US may be an effective method in the initial management of patients with suspected rotator cuff pathology. Using this method, a definitive diagnosis and treatment plan was established in 88% of patients with the remaining 12% requiring an MRI. A small percentage (6%) of patients with larger than expected full-thickness rotator cuff tears and/or alternate glenohumeral pathology (e.g., labral tear) would be missed at initial evaluation