Editorial Commentary: Muscle Advancement, Footprint Medialization, and Repair Medialization Could Improve Healing and Clinical Outcomes of Massive Rotator Cuff Tears as a Result of Low-Tension Repair.

The goal of massive, retracted rotator cuff repair surgery is structural healing that produces pain relief and strength restoration. Healing is difficult to achieve in patients with large, retracted, chronic, and fatty degenerated tears. High repair tension previously has been shown to be a risk factor for clinically and structurally failed repairs. Repair tension can be decreased by arthroscopic mobilization and muscle advancement (AMA) of the supraspinatus and infraspinatus muscle bellies from their scapular origins with subsequent lateralization of the muscle-tendon units toward the repair site. Linked double-row repair of the tendons after AMA has been shown to improve the outcomes of repairs in high-risk rotator cuff repairs. Surgeons should consider adding AMA to their intraoperative armamentarium for use in retracted cuff tears when traditional techniques fail to achieve a low-tension repair state.

Subacromial Surgery for Irreparable Posterosuperior Rotator Cuff Tears.

The irreparable posterosuperior rotator cuff tear describes a tear of the supraspinatus and/or infraspinatus tendon that is massive, contracted, and immobile in both the anterior-posterior and medial-lateral directions. Patients with an intact subscapularis and preserved forward elevation are challenging to treat because there is not a consensus treatment algorithm. For low-demand, elderly patients, several subacromial surgical options are available that can provide pain relief without the risks or burden of rehabilitation posed by reverse total shoulder arthroplasty or a complex soft-tissue reconstruction (e.g., superior capsular reconstruction, tendon transfer, bridging grafts). Debridement, more specifically the "smooth-and-move" procedure, offers a reliable outcome with documented improvements in pain and function at long-term follow-up. Similarly, the biodegradable subacromial balloon spacer (InSpace; Stryker, Kalamazoo, MI) has been shown to significantly improve pain and function in patients who are not responsive to nonoperative treatment. Disease progression with these options is possible, with a small percentage of patients progressing to rotator cuff arthropathy. Biologic tuberoplasty and bursal acromial reconstruction are conceptually similar to the balloon spacer but instead use biologic grafts to prevent bone-to-bone contact between the humeral head and the acromion. Although there is no single gold standard treatment, the variety of surgical techniques allows patients and surgeons to effectively manage these challenging situations.

Glenoid augmentation for subcritical bone loss: a narrative review.

Background and Objective: Anterior shoulder instability can be debilitating for young, active individuals, and increasing magnitudes of glenoid bone loss (GBL) predisposes patients to recurrent instability and increases the likelihood of failure of soft-tissue only repairs. It is widely accepted that GBL >25% should be treated with a glenoid bone grafting procedure. However, consensus is lacking on the optimal management in the setting of subcritical GBL, typically classified as >13.5%. This article reviews the pathoanatomy relevant to anterior shoulder instability and subcritical GBL, while highlighting existing evidence regarding open augmentation procedures in comparison to other treatment options for this subpopulation. Methods: A narrative review of the current literature was conducted focusing on subcritical GBL in anterior glenoid stabilization procedures, including review of forward citation and reference lists of selected articles. Key Content and Findings: Computed tomography (CT) is the modality of choice for obtaining precise measurements of subcritical GBL, defined as <13.5%, using the best-fit circle method. There is debate surrounding the optimal surgical management of subcritical GBL. Arthroscopic Bankart repair (ABR) remains the predominate surgery performed for primary anterior shoulder instability, while glenoid augmentation and open Bankart repair continue to be used sparingly in the United States. Historically, the Latarjet procedure was considered for substantial glenoid defects, but the illumination of subcritical GBL has expanded its indications. Arthroscopic, soft tissue-only repairs with the addition of remplissage, has been shown to have similar 2-year outcomes to the Latarjet in patients with >15% GBL, which has been limited in the study of subcritical GBL. Additionally, utilization of distal tibial allograft and local autograft is becoming increasingly prevalent. However, again, with limited prospective studies in the subcritical GBL population. Conclusions: There is no consensus regarding the optimal treatment approach to recurrent shoulder instability in the setting of subcritical GBL. Conversely, there is a growing agreement that isolated ABR is likely inadequate and subcritical GBL should prompt consideration of a more robust operation. To this end, interest in glenoid bone augmentation continues to grow as a reliable technique for recreating the native architecture and restoring glenohumeral stability are developed.

Arthroscopic Management of Arthrofibrosis After Hemiarthroplasty for Proximal Humerus Fracture Dislocation.

Poor functional outcomes after hemiarthroplasty for proximal humerus fractures are common, yet revision surgery is relatively rare. Arthroscopic treatment for postoperative stiffness can be considered in the setting of functional limits to glenohumeral range of motion impacting activities of daily living after adequate conservative treatment with physical therapy and in the setting of healed, well-positioned tuberosities and humeral components. This Technical Note illustrates a stepwise approach to an arthroscopic lysis of adhesions and capsular release for the treatment of arthrofibrosis of the shoulder. The advantages of this technique include an alternative approach to entering the glenohumeral joint under direct subacromial visualization and a 2-posterior portal approach to the inferior and anteroinferior capsule, which can be challenging to achieve in the setting of severe postsurgical arthrofibrosis.

Subacromial Balloon Spacer for the Massive Irreparable Cuff Tear.

PURPOSE OF REVIEW: The purpose of the review is to provide an updated overview of a relatively novel but controversial surgical device (InSpace subacromial balloon, Stryker, Kalamazoo, MI) that can be readily incorporated into the armamentarium of the shoulder surgeon. The authors review the critical clinical and surgical decision-making aspects of InSpace. A recommended surgical technique and rehabilitation protocol are outlined. The authors present a nuanced view of the balloon spacer in the continuum of care of the irreparable rotator cuff tear. RECENT FINDINGS: Within the last year, two Level I clinical trials have been published, and the data from these studies offer conflicting evidence regarding the utility of the subacromial balloon spacer. The current review contrasts these two recent studies and offers a framework by which the available evidence can be practically understood with respect to clinical decision-making. The literature currently supports a limited indication for use of InSpace: the elderly, low-demand patient with preserved active range of motion with an operatively irreparable, posterosuperior rotator cuff tear with an intact subscapularis. The InSpace subacromial balloon spacer is a simple device that can yield substantial improvements in clinical outcomes among a subset of patients with irreparable rotator cuff tears. InSpace is not a panacea for the complex, irreparable rotator cuff tear. Individualized decision-making is necessary in this diverse and challening patient population.

The Triple-Double Technique of Arthroscopic Hill-Sachs Remplissage.

Surgeons are increasingly treating Hill-Sachs lesions arthroscopically by suturing the posterior rotator cuff and capsule into the defect, a procedure known as "remplissage." A number of remplissage techniques have been described in the literature, and these often vary by the number and location of suture anchors. The "triple-double" technique of arthroscopic Hill-Sachs remplissage can be used for larger lesions. This technique utilizes a three-anchor configuration secured by interconnected double-mattress sutures to provide durable fixation through a large contact area between the capsulotenodesis tissue and the prepared bone bed to theoretically optimize healing.

Arthroscopic Rotator Cuff Repair, Manipulation Under Anesthesia, and Capsular Release for Concurrent Rotator Cuff Tear and Adhesive Capsulitis Maintain Improvements in Outcomes and Range of Motion at Minimum 5-Year Follow-Up.

Purpose: To characterize the outcomes and range of motion at a minimum 5-year follow-up in patients undergoing arthroscopic rotator cuff repair (ARCR) with simultaneous manipulation under anesthesia (MUA) and capsular release (CR) for concurrent RC and adhesive capsulitis and to compare active range of motion of the operative and nonoperative shoulder. Methods: Patients undergoing ARCR with MUA and CR by a single surgeon were retrospectively reviewed and prospectively evaluated at a minimum of 5 years postoperatively. Standardized surveys, examinations, and patient-reported outcomes were recorded pre- and postoperatively. Outcome measures included range of motion, American Shoulder and Elbow Surgeon Score (ASES), visual analog score (VAS) for pain, Simple Shoulder Test (SST), subjective shoulder value (SSV), functional level, and satisfaction. Results: Fourteen consecutive patients were evaluated at 7.5 ± 1.6 years' follow-up. At final follow-up, the affected shoulder had substantial improvements in ASES (P < .001), VAS (P < .001), SST (P = .001), and SSV (P < .001), with similar ASES, VAS, SST, and SSV compared with the contralateral side. Range of motion was also similar to the contralateral side at final follow-up for forward elevation and internal rotation, but external rotation was noted to be 10.77 ± 17.06° (95% confidence interval 0.46-21.08, P = .042) more limited. Two patients (14%) underwent revision MUA and CR for stiffness at 6 months and 12 months' postoperatively. Conclusions: This study highlights significantly improved and maintained patient-reported outcomes and range of motion at minimum 5-year follow-up in patients undergoing concomitant ARCR, MUA, and CR. These results provide further evidence that preoperative stiffness in the setting of rotator cuff tear can be managed concurrently; however, patients may remain at an increased risk for recurrent stiffness and external rotation loss. Level of Evidence: Level IV, therapeutic case series.

The Most Popular YouTube Videos About Shoulder Replacement Are of Poor Quality for Patient Education.

Purpose: To characterize the quality of YouTube total shoulder arthroplasty videos as a source of patient information using the DISCERN instrument. Methods: An analysis of the YouTube video library was performed, using a string of 6 search terms related to "total shoulder replacement" and "total shoulder arthroplasty" in the YouTube search engine. The first 20 videos from each search (n = 120) were selected. The top 25 most viewed videos were compiled, screened, and evaluated with the DISCERN score in the final analysis. Pearson's correlation coefficients were used to assess the correlation of DISCERN scores and video characteristics. Inter-rater reliability was calculated with the conger kappa score for multiple raters. Results: Twenty-five videos met inclusion criteria, 13 (52%) were produced by academic institutions, 7 (28%) by physicians, and 5 (20%) by commercial entities. Median total DISCERN score was 33 out of 80 (IQR: 28-44). The overall total DISCERN scores, showed no correlation with video likes or views and was negatively correlated with video power index (r = -0.75, P = .001). No association between total shoulder arthroscopy video source and DISCERN score could be demonstrated. All videos analyzed scored poorly by the DISCERN instrument. Conclusions: The current most popular shoulder replacement videos on YouTube are low-quality patient education resources. Furthermore, our study found no correlation between video popularity, as measured by the number of views and the DISCERN score. Clinical Relevance: Successful outcomes following total shoulder arthroplasty may be influenced by the quality of information patients receive.

Documented Contact Allergy Impacts Risk for Surgical Adhesive-Associated Contact Dermatitis after Shoulder Arthroplasty.

Purpose: The purpose of this study is to report on the incidence and risk factors for allergic contact dermatitis (ACD) in patients who received Prineo after total shoulder arthroplasty (SA). Methods: A retrospective case-control study was conducted to investigate patients who experienced ACD after having SA by a single surgeon during a defined period when Prineo was routinely used as an adjunct to wound closure. Known risk factors for ACD (e.g., history of contact dermatitis, smoking) were analyzed for association development of Prineo-associated ACD using Fisher exact and Wilcoxon rank sum tests. Results: From June 2019 through July 2021, 236 consecutive patients were identified as having Prineo applied after SA. Nine cases of Prineo-ACD (3.8%) were documented, whereas 227 patients were unaffected. In all 9 affected patients, the complication was identified and treated without compromising the outcome of the SA. Previous allergy to medical adhesives was a statistically significant risk factor for Prineo-associated ACD in this series (P = .01). The odds of having Prineo-associated ACD among those with adhesive or contact allergy was 38.5 times that of their nonallergic counterparts in a multivariate model. Conclusions: Prineo adhesive ACD had an incidence of 3.8% in this study, and a history of adhesive or contact allergy was highly associated with its development. Level of Evidence: Level III, case-control study.

Compliance with Electronic Patient Reported Outcome Measure System Data Collection Is 51% Two-years After Shoulder Arthroscopy.

Objective: To determine patient compliance in completing electronic patient-reported outcome measures (PROMs) following arthroscopic shoulder surgery and identify risk factors for noncompliance. Methods: A retrospective review of compliance data was performed for patients who underwent arthroscopic shoulder surgery by a single surgeon in a private practice setting from June 2017 to June 2019. All patients were enrolled in Surgical Outcomes System (Arthrex) as a part of routine clinical care, and outcome reporting was integrated into our practice electronic medical record. Patient compliance with PROMs was calculated at preoperative, three-month, 6-month, 1-year, and 2-year follow-up time points. Compliance was defined as a complete patient response to each assigned outcome module in the database over time. Logistic regression for compliance at the one-year timepoint was performed to assess for factors associated with survey compliance. Results: Compliance with PROMs was highest preoperatively (91.1%) and decreased at each subsequent time point. The largest decrease in compliance with PROMs occurred between the preoperative and 3-month follow-up time points. Compliance was 58% at 1 year and 51% at 2 years after surgery. Overall, 36% of patients were compliant at all individual time points. There were no significant predictors of compliance with regard to age, sex, race, ethnicity, or procedure. Conclusions: Patient compliance with PROMs decreased over time with the lowest percentage of patients completing electronic surveys at the traditional 2-year follow-up for shoulder arthroscopy. In this study, basic demographic factors were not predictive of patient compliance with PROMs. Clinical Relevance: PROMs are commonly collected after arthroscopic shoulder surgery; however, low patient compliance may affect their utility in research and clinical practice.

Similar Value Demonstrated in the Short-Term Outcomes of Superior Capsular Reconstruction and Reverse Shoulder Arthroplasty for Massive Rotator Cuff Tears.

Purpose: The purposes of this study were to investigate the difference in value (benefit to cost ratio) of dermal allograft superior capsular reconstruction (SCR) versus reverse total shoulder arthroplasty (rTSA) for the treatment of massive rotator cuff tears (MRCTs) without arthritis; to compare the patient populations selected for the operations and report pre- and postoperative functional data; and to understand other characteristics of the 2 operations, including operating time, use of institutional resources, and complications. Methods: A retrospective, single-institution analysis during the study period 2014-2019 with MRCT treated with SCR or rTSA by 2 surgeons with complete institutional cost data and minimum 1-year clinical follow-up with American Shoulder and Elbow Surgeons (ASES) score. Value was defined as ΔASES/(total direct costs/$10,000). Results: Thirty patients underwent rTSA and 126 patients SCR during the study period with significant differences noted in patient demographics and tear characteristics between the groups (patients who underwent rTSA were older, less male, had more pseudoparalysis, had greater Hamada and Goutallier scores, and had more proximal humeral migration). Value was 25 and 29 (ΔASES/$10,000) for rTSA and SCR, respectively (P = .7). The total costs of rTSA and SCR were $16,337 and $12,763, respectively (P = .7). Both groups experienced substantial improvements in ASES scores: 42 for rTSA vs 37 for SCR (P = .6). The operative time for SCR was much longer (204 vs 108 minutes, P < .001) but complication rate lower (3% vs 13%, P = .02) versus rTSA. Conclusions: In a single institutional analysis of the treatment of MRCT without arthritis, rTSA and SCR demonstrated similar value; however, the value calculation is highly dependent on institution specific variables and duration of follow-up. The operating surgeons demonstrated different indications in selecting patients for each operation. rTSA had an advantage over SCR in shorter operative time, whereas SCR demonstrated a lower complication rate. Both SCR and rTSA are demonstrated to be effective treatments for MRCT at short-term follow-up. Level of Evidence: III, retrospective comparative study.

Arthroscopic Excision for Painful Acromial Fracture Nonunion After Reverse Total Shoulder Replacement.

Acromial stress fracture is a well-known complication after reverse shoulder arthroplasty. Although some patients are asymptomatic, others may present with reproducible pain to palpation and signs of impingement. Generally, the initial mode of treatment is conservative; however, surgical intervention is considered in patients with painful nonunion and displaced fragments. Although open reduction techniques are most common, Levy type I fragments may be amenable to excision. This technical note provides a stepwise approach to arthroscopic excision for painful nonunited acromial stress fractures after reverse shoulder arthroplasty.

Arthroscopic Management of Stiffness and Anterior Shoulder Pain Following Reverse Shoulder Arthroplasty.

Arthroscopy following shoulder arthroplasty has primarily been described as a diagnostic tool in the setting of unexplained pain. However, this tool also can be used to potentially manage postoperative stiffness and pain following reverse shoulder arthroplasty. This Technical Note provides a stepwise approach to assessing and addressing limitations in range of motion as well as causes of postoperative impingement following reverse shoulder arthroplasty.

Radiographic parameters associated with excellent versus poor range of motion outcomes following reverse shoulder arthroplasty.

BACKGROUND: The purpose was to evaluate the relationship of component size and position to postoperative range of motion following reverse shoulder arthroplasty. The hypothesis was that increased lateralization, larger glenospheres, and a decreased acromiohumeral distance would be associated with excellent postoperative range of motion. METHODS: A retrospective multicenter study was performed at a minimum of one year postoperatively on 160 patients who underwent primary reverse shoulder arthroplasty with a 135° humeral component. Outcomes were stratified based on postoperative forward flexion and external rotation into excellent (n = 42), defined as forward flexion >140° and external rotation > 30°, or poor (n = 36), defined as forward flexion <100° and external rotation < 15°. Radiographic measurements and component features were compared between the two groups. RESULTS: A larger glenosphere size was associated with an excellent outcome (p = 0.009). A 2-mm posterior offset humeral cup (p = 0.012) and an increased inferior glenosphere overhang (3.1 mm vs 1.4 mm; p = 0.002) were also associated with excellent outcomes. Humeral lateralization and distalization were not associated with an excellent outcome.Conclusion: Larger glenosphere size and inferior positioning as well as posterior humeral offset are associated with improved postoperative range of motion following reverse shoulder arthroplasty. LEVEL OF EVIDENCE: Level 3, retrospective comparative study.

Prospective 1-Year Outcomes Are Maintained at Short-Term Final Follow-Up After Superior Capsular Reconstruction Augmentation of Complete Rotator Cuff Repair.

PURPOSE: To evaluate the outcomes of arthroscopic superior capsular reconstruction (SCR) augmentation of complete, massive rotator cuff repair (RCR). METHODS: A retrospective study of dermal allograft SCR-augmented RCRs performed by a single surgeon from June 2016 through December 2017 was performed with the following inclusion criteria: massive rotator cuff tear amenable to complete repair but with poor-quality native rotator cuff tissue. Radiographic follow-up was performed at 1 year, and clinical follow-up was performed at both 1 year and a minimum 2 years after surgery. Clinical follow-up included the American Shoulder and Elbow Surgeons score, visual analog scale score for pain, Subjective Shoulder Value score, active forward elevation, and external rotation. Radiographs and magnetic resonance imaging (MRI) scans were assessed for muscle quality using the Goutallier classification, and graft and cuff integrity was assessed according to the Sugaya classification. RESULTS: The inclusion criteria were met by 24 patients at 1 year and by 18 (75%) at a minimum of 2 years postoperatively. Patient-reported outcomes were improved compared with preoperative data and were maintained at minimum 2-year follow-up, with median American Shoulder and Elbow Surgeons scores of 42.5 (interquartile range [IQR], 30.8-58.7) versus 93.9 (IQR, 82.4-100) (P < .001); median Subjective Shoulder Value scores of 30 (IQR, 20-50) versus 90 (IQR, 86.2-97.2) (P < .001); and median visual analog scale pain scores of 5.5 (IQR, 1-9) versus 0 (IQR, 0-0.8) (P = .001). Evaluation of graft and tendon healing on postoperative MRI revealed poor interobserver agreement and showed 10 completely healed grafts (42%), 9 partially healed grafts (38%), and 5 completely disrupted grafts (21%), with 42% of supraspinatus tendons and 54% of infraspinatus tendons healed. CONCLUSIONS: SCR with dermal allograft augmentation of complete RCR with poor-quality tissue shows very good clinical outcomes at minimum 2-year follow-up. Poor interobserver agreement regarding postoperative graft and rotator cuff integrity by MRI was found. The healing rate for the SCR grafts was 79%. The rates of healing of the native supraspinatus and infraspinatus tendons were 42% and 54%, respectively. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Distal biceps tendon repair: cost analysis of single- versus double-incision techniques in an ambulatory surgery center.

Background: The purpose of this study was to compare the cost differences for single- versus double-incision distal biceps repair at an ambulatory surgery center (ASC) given that similar clinical outcomes have been reported between these methods. Methods: A retrospective review of financial and medical records was completed for patients who underwent distal biceps tendon repair over a three-year period at a single private orthopedic practice. Variables analyzed include the cost to the ASC of operative time and the cost of differential surgical supplies, specifically implants and disposable supplies. Results: A total of 10 surgeons performed 104 repairs. Nine surgeons performed repairs through a single incision with use of cortical button or suture anchor fixation, and one surgeon performed transosseous suture fixation through a double-incision approach. The median tourniquet time and procedure length were 31 (interquartile range [IQR] 27-40) and 44 (IQR 39-54) minutes for single-incision repairs and 68 minutes (IQR 61-75) and 110 minutes (IQR 103-113) for double-incision repairs which were significantly different across groups (P < .001, P < .001). The total surgical cost (operative time, implants, and disposables) for single-incision repairs was a median of $758 (IQR 732-803) compared with $606 (IQR 567-629) for double-incision repairs (P < .001). However, the procedure cost with implants (not including disposables) was not significantly different for single- (median [Mdn] = $500 [IQR 475-552]) and double-incision repairs (Mdn $552 [IQR 514-564]) (P = .14) although the procedure cost with disposables (not including implant costs) favored single-incision repairs (Mdn = $478 [IQR 452-523]) over double-incision repairs (Mdn = $606 [IQR 567-629]) (P < .001). Conclusion: In a single surgery center, single-incision distal biceps repairs utilizing an implant were performed more expeditiously than double-incision repairs with a transosseous technique but incurred greater surgical costs. Differences in surgical time cost between the two approaches could be consequential for ASCs and other stakeholders.

Bone Block Augmentation of the Posterior Glenoid for Recurrent Posterior Shoulder Instability Is Associated With High Rates of Clinical Failure: A Systematic Review.

PURPOSE: To determine whether posterior glenoid bone block augmentation performed for the treatment of recurrent posterior shoulder instability succeeds in restoring stability and is associated with rates of complications or clinical failures comparable to other glenoid bone augmentation procedures. METHODS: A comprehensive search of PubMed, MEDLINE, and EMBASE databases was performed. Level of evidence studies I to IV pertaining to posterior bone block augmentation reporting on outcomes or complications were included. The search was carried out in accordance with the Preferred Reported Items for Systematic Reviews and Meta-analyses guidelines. RESULTS: Screening of titles, abstracts, and manuscripts with application of inclusion and exclusion criteria yielded 17 full-text articles reporting on 269 shoulders undergoing bone block augmentation. Surgical technique varied between studies with regard to graft type (iliac crest, 13 studies; scapular spine, 2; acromion, 1; distal tibia allograft, 1), graft positioning (medial to 1.5 cm lateral to glenoid surface, equatorial to subequatorial), and open versus arthroscopic technique (open, 10 studies; arthroscopic, 4; both, 3). Four of the 8 studies with pre- and postoperative patient-reported outcomes (PROs) showed significant improvements in these outcomes at final follow-up. The postoperative outcomes ranged from 60 to 90 for Rowe scores (n = 7 studies) and 79 to 90 for Walch-Duplay scores (n = 7 studies). Complications were commonly encountered, with high rates of recurrent instability (0% to 73%) and revision procedures (0% to 67%) across different studies. CONCLUSION: Posterior bone block augmentation for recurrent posterior shoulder instability does not reliably yield substantial improvements in PROs, and complications are frequently observed. The substantial heterogeneity across studies and the small number of patients precludes any substantive judgements as to the superiority of one surgical technique over another. LEVEL OF EVIDENCE: IV, systematic review of level III and IV studies.

Variability in total shoulder arthroplasty planning software compared to a control CT-derived 3D printed scapula.

BACKGROUND: Two techniques exist from which all 3D preoperative planning software for total shoulder arthroplasty are based. One technique is based on measurements constructed on the mid-glenoid and scapular landmarks (Landmark). The second is an automated system using a best-fit sphere technique (Automated). The purpose was to compare glenoid measurements from the two techniques against a control computed tomography-derived 3D printed scapula. METHODS: Computed tomography scans of osteoarthritic shoulders of 20 patients undergoing primary total shoulder arthroplasty were analyzed with both 3D planning software techniques. Measurements from a 3D printed scapula (Scapula) from the true 3D computed tomography scan served as controls. Glenoid version and inclination measurements from each group were blinded and reviewed. RESULTS: In 65% (Automated) and 45% (Landmark) of cases, either inclination or version varied by 5° or more versus 3D printed scapula. Significant variability in version differences compared to the scapula group existed (p = 0.007). Glenoid version from the Scapula = 13.0° ± 10.6°, Automated = 15.0° ± 13.9°, and Landmark = 12.2° ± 7.8°. Inclination from Scapula = 5.4° ± 7.9°, Automated = 6.1° ± 12.6°, and Landmark = 6.2° ± 9.1°. DISCUSSION: A high percentage of cases showed discrepancies in glenoid inclination and version values from both techniques. Surgeons should be aware that regardless of software technique, there is variability compared to measurements from a control 3D computed tomography printed scapula.

Histologic case series of human acellular dermal matrix in superior capsule reconstruction.

BACKGROUND: Acellular dermal matrix (ADM) allografts are commonly used in the surgical treatment of complex and irreparable rotator cuff tears. Multiple studies report that superior capsule reconstruction (SCR) using ADM has resulted in short-term clinical success as assessed via radiographic and patient-reported outcomes. However, limited information is available regarding the biologic fate of these grafts in human subjects. This case series describes histologic results from 8 patients who had reoperations, during which the previously implanted ADMs were removed. These explanted ADMs were subjected to histologic analysis with the hypothesis that they would have evidence of recellularization, revascularization, and active remodeling. METHODS: Eight patients, 38-82 years old, underwent reoperation 6-38 months after undergoing SCR. ADM explants were voluntarily shipped to the manufacturer for histologic analysis. Each graft's structure and composition were qualitatively evaluated by 1 or more of the following histologic stains: hematoxylin and eosin, safranin O, and Russell-Movat pentachrome. Pan-muscle actin staining also assessed the level of neovascularization, potential myoblast or myocyte infiltration, and muscle tissue development in the graft, and was analyzed to determine the proportion of graft that had been recellularized in situ. RESULTS: Grafts showed varying levels of gross and microscopic incorporation with the host. An uneven, but high, overall degree of recellularization, revascularization, and active remodeling was observed. The degree of remodeling correlated with implant duration. These results are consistent with successful biologic reconstruction of the superior shoulder capsule. CONCLUSIONS: The present histologic analysis suggests that ADMs used in SCR undergo active recellularization, revascularization, and remodeling as early as 6 months after implantation, and that graft recellularization positively correlates with duration of implantation. These results represent a significant advancement in our knowledge regarding biologic incorporation of ADMs used in SCR.