The latissimus dorsi creates a dynamic track for the inferior angle of the scapula during arm abduction in humans.

BACKGROUND: The importance of several scapulothoracic muscles, including trapezius and serratus anterior, in maintaining physiological scapula kinematics has been highlighted in the past. However, the relationship between the scapula and the latissimus dorsi muscle remains unclear. Our clinical surgical observation is that the latissimus dorsi does not directly attach but rather runs superficial to the inferior angle of the scapula. Based on this observation, we hypothesise that the latissimus dorsi creates a dynamic track on which the scapula glides under the muscle belly during elevation of the arm, creating the latissimus-scapula overlap (LSO). METHODS: All consecutive patients who had a whole-body computed tomography scan (CT) in case of polytrauma evaluation between 2018 and 2021, with complete depiction of the scapula and latissimus dorsi muscle, were analysed. 150 shoulders in 90 patients with arms up were matched according to their age (within five years), gender, and affected side with 150 shoulders in 88 patients with arms down. Patients with pathologies of the upper extremities or thorax that potentially could alter LSO measurements were excluded. LSO was calculated as a ratio of the measured area of the latissimus dorsi projection on the scapula and the total scapula area. RESULTS: The mean age of the 178 patients (48 females; 13 males) was 60 years. The arms-up group showed a significantly higher LSO than the arms-down group (19.9 ± 6.3% vs. 2.7 ± 2.2%; p < 0.0001). In the arms-up group, approximately one fifth of the scapula was overlapped inferiorly by the muscle belly of the latissimus dorsi, contrary to the almost non-existing LSO in the arms-down group. CONCLUSION: With arms up, humans show a significantly higher LSO in comparison to arms down indicating that the latissimus dorsi indeed creates a dynamic track on which the scapula is forced to travel during abduction of the arm. This finding of increased LSO during the elevation of the arm warrants further consideration of the role of the latissimus dorsi in scapula kinematics and potentially scapular dyskinesis. LEVEL OF EVIDENCE: Level two diagnostic study.

All-Arthroscopic Falciform Portal Biceps Tenodesis.

Biceps tenodesis has been proven to be an effective treatment for biceps tendon and superior labral pathology. Many techniques including both open and arthroscopic approaches have been reported. Open techniques afford management of the entire proximal biceps tendon but are limited by wound healing issues, increased bleeding, and increased surgical time. Arthroscopic tenodesis offers benefits in terms of surgical efficiency, cosmesis, and bleeding risk. However, standard arthroscopic tenodesis only addresses intra-articular biceps pathology. In this report we describe an all-arthroscopic biceps tenodesis technique at the suprapectoral region of the humerus using knotless suture anchor fixation.

Hamstring Tendon Autograft Is Associated With Increased Knee Valgus Moment After Anterior Cruciate Ligament Reconstruction: A Biomechanical Analysis.

BACKGROUND: There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament reconstruction (ACLR). PURPOSE/HYPOTHESIS: This study aimed to compare biomechanical outcomes during a drop vertical jump (DVJ) between patients with a hamstring tendon (HT) autograft, quadriceps tendon (QT) autograft with bone block, QT autograft without bone block, and bone-patellar tendon-bone autograft at 6 months postoperatively in an adolescent population. The authors' hypothesized there would be differences in DVJ biomechanics between athletes depending on the type of autograft used. STUDY DESIGN: Controlled laboratory study. METHODS: Patients aged 8 to 18 years who underwent primary ACLR were included for analysis. Kinematic and kinetic data collected during a DVJ using a 3-dimensional computerized marker system were assessed at 6 months after ACLR and compared with the uninjured contralateral limb. RESULTS: A total of 155 participants were included. There were no significant differences in terms of age, sex, or affected leg (P≥ .1973) between groups. The HT group was significantly associated with a larger knee valgus moment at initial contact compared with the QT group (28 × 10-2 vs -35 × 10-2 N·m/kg, respectively; P = .0254) and a significantly larger maximum hip adduction moment compared with the QT with bone block group (30 × 10-2 vs -4 × 10-2 N·m/kg, respectively; P = .0426). Both the QT with bone block (-12 × 10-2 vs -3 × 10-2 N·m/kg, respectively; P = .0265) and QT (-13 × 10-2 vs -3 × 10-2 N·m/kg, respectively; P = .0459) groups demonstrated significantly decreased mean knee extension moments compared with the HT group. CONCLUSION: The findings of this study suggest that utilizing an HT autograft resulted in a significantly increased knee valgus moment at initial contact compared with a QT autograft without bone block at 6 months after ACLR in adolescent patients performing a DVJ. A QT autograft was found to be associated with significantly decreased extensor mechanism function compared with an HT autograft. CLINICAL RELEVANCE: This study adds unique kinematic and kinetic information regarding various ACLR autograft options and highlights the biomechanical deficits that should be taken into consideration in rehabilitation.

Surgical Management of Massive Irreparable Cuff Tears: Superior Capsule Reconstruction and Rotator Cable Reconstruction.

PURPOSE OF REVIEW: Massive irreparable rotator cuff tears (MIRCTs) present treatment challenges. Recently, superior capsule reconstruction (SCR) and anterior cable reconstruction have emerged as surgical options, but no single approach is superior. This review provides an overview of SCR and cable reconstruction techniques, including biomechanical studies, clinical outcomes, and surgical considerations. RECENT FINDINGS: Biomechanical studies show SCR with autografts or allografts improves glenohumeral stability and mechanics. Clinical outcomes of SCR demonstrate improved range of motion, function scores, and pain relief in short-term studies. Anterior cable reconstruction reduces superior humeral head translation and subacromial pressures in biomechanical models. Early clinical studies report improved rotator cuff healing and outcomes for cable reconstruction in specific irreparable tear patterns. SCR and cable reconstruction are viable surgical options for MIRCTs based on early encouraging results. However, higher-level comparative studies with long-term follow-up are still needed. Careful consideration of tear pattern, patient factors, and surgical goals is required to optimize treatment of MIRCTs. Further research is necessary to determine the optimal role for these procedures.

Functional Return-to-Sport Testing Demonstrates Inconsistency in Predicting Short-Term Outcomes Following Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: To systematically review the relationship between functional testing at the time of return to sport (RTS) and short-term outcomes, such as second anterior cruciate ligament (ACL) tear and return to a preinjury level of sport, among athletes who underwent anterior cruciate ligament reconstruction (ACLR). METHODS: A systematic literature search was performed in MEDLINE, EMBASE, Scopus, and Web of Science to identify studies examining athletes who underwent functional RTS testing and were followed for at least 12 months following ACLR. Studies were screened by 2 reviewers. A standardized template was used to extract information regarding study characteristics, ACLR information, functional test results, and risk factors associated with retear or reduced RTS. RESULTS: Of the 937 studies identified, 22 met the inclusion criteria. The average time between ACLR and RTS testing was 8.5 months. Single leg hop for distance performance had no association with retear risk in any study and no association with RTS rates in most studies. Quadriceps strength had conflicting results in relation to retear risk, whereas it had no relationship with RTS rates. Rates of reinjury and RTS were similar between patients who passed and did not pass combined hop and strength batteries. Asymmetric knee extension and hip moments, along with increased knee valgus and knee flexion angles, demonstrated increased risk of retear. CONCLUSIONS: Individual hop and strength tests that are often used in RTS protocols following ACLR may have limited and inconsistent value in predicting ACL reinjury and reduced RTS when used in isolation. Combined hop and strength test batteries also demonstrate low sensitivity and negative predictive value, highlighting conflicting evidence to suggest RTS testing algorithm superiority. Biomechanical assessment is promising for stratifying ACL reinjury risk, but further research is necessary. LEVEL OF EVIDENCE: Level IV, systematic review of Level I-IV studies.

Magnetic Resonance Imaging Analysis Demonstrates Improved Reliability in Measuring Shoulder Glenoid Bone Loss Using a Two-Thirds Glenoid Height Technique Compared to the "Best-fit Circle".

PURPOSE: To evaluate the superior to inferior glenoid height as a reliable reference in best-fit circle creation for glenoid anatomy. METHODS: The morphology of the native glenoid was evaluated using magnetic resonance imaging (MRI) in patients without shoulder instability. Using T1 sagittal MRI images, 2 reviewers independently estimated glenoid size using the two-thirds technique and the "best-fit circle" technique at 2 different times. A Student t-test was used to determine significant difference between the two methodologies. Inter- and intra-rater reliability were calculated using interclass and intraclass coefficients. RESULTS: This study included 112 patients. Using the results of glenoid height and "best-fit circle" diameter, the diameter of the "best-fit circle" was found to intersect the glenoid line at 67.8% of the glenoid height on average. We found no significant difference between the 2 measures of glenoid diameter (27.6 vs 27.9, P = .456). The interclass and intraclass coefficients for the two-third method were 0.85 and 0.88, respectively. The interclass and intraclass coefficients for the perfect circle methods were 0.84 and 0.73, respectively. CONCLUSIONS: We determined that the diameter of a circle placed on the inferior glenoid using the "best-fit circle" technique corresponds to 67.8% of the glenoid height. Additionally, we found that constructing a perfect circle using a diameter equal to two-thirds the height of the glenoid may improve intraclass reliability. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

Rotator Cuff Repair with Knotless All-Suture Medial Row Anchors and Biceps Autograft Augmentation.

Incomplete healing and/or functional failure following rotator cuff tear repair remains a challenging problem for both patients and surgeons. Augmentation strategies are growing to increase healing through biologic and mechanical mechanisms to improve functional results after arthroscopic rotator cuff repair. The majority of currently described augmentation techniques use allograft tissue. An alternative, low-cost, autograft option for augmentation is the use of the long head of biceps tendon autograft as a free functional graft. Here, we describe the use of autograft biceps tendon as a viable option for augmentation of double-row rotator cuff repair with knotless all-suture suture anchors.

Performance-Enhancing Drugs in Healthy Athletes: An Umbrella Review of Systematic Reviews and Meta-analyses.

CONTEXT: Many clinicians, trainers, and athletes do not have a true understanding of the effects of commonly used performance-enhancing drugs (PEDs) on performance and health. OBJECTIVE: To provide an evidence-based review of 7 commonly used pharmacological interventions for performance enhancement in athletes. DATA SOURCES: PubMed and Scopus databases were searched on April 8, 2022. STUDY SELECTION: Systematic reviews (SRs) and meta-analyses (MAs) assessing the performance-enhancing effects of the following interventions were included: androgenic anabolic steroids (AAS), growth hormone (GH), selective androgen receptor modulators (SARMs), creatine, angiotensin-converting enzyme (ACE)-inhibitors, recombinant human erythropoietin (rHuEPO), and cannabis. STUDY DESIGN: Umbrella review of SRs and MAs. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Primary outcomes collected were (1) body mass, (2) muscle strength, (3) performance, and (4) recovery. Adverse effects were also noted. RESULTS: A total of 27 papers evaluating 5 pharmacological interventions met inclusion criteria. No studies evaluating SARMs or ACE-inhibitors were included. AAS lead to a 5% to 52% increase in strength and a 0.62 standard mean difference in lean body mass with subsequent lipid derangements. GH alters body composition, without providing a strength or performance benefit, but potential risks include soft tissue edema, fatigue, arthralgias, and carpel tunnel syndrome. Creatine use during resistance training can safely increase total and lean body mass, strength, and performance in high-intensity, short-duration, repetitive tasks. Limited evidence supports rHuEPO benefit on performance despite increases in both VO2max and maximal power output, and severe cardiovascular risks are documented. Cannabis provides no performance benefit and may even impair athletic performance. CONCLUSION: In young healthy persons and athletes, creatine can safely provide a performance-enhancing benefit when taken in controlled doses. AAS, GH, and rHuEPO are associated with severe adverse events and do not support a performance benefit, despite showing the ability to change bodily composition, strength, and/or physiologic measures. Cannabis may have an ergolytic, instead of ergogenic, effect.

The influence of posterior acromial morphology on outcomes and return to pushups in young patients undergoing arthroscopic posterior capsulolabral repair.

Background: Prior evidence has identified specific posterior acromial morphology as significantly associated with unidirectional posterior shoulder instability. The purpose of this study is to determine the influence of posterior acromial morphology on the outcomes of arthroscopic posterior capsulolabral repair (APCLR) for unidirectional posterior shoulder instability. Additionally, we sought to determine the influence of posterior acromial morphology on the rate and time to return to pushups following APCLR. Methods: We performed a retrospective review of prospectively collected data. The study included consecutive patients undergoing APCLR. Data collected included demographics, radiographic measurements including posterior acromial height (PAH) and posterior acromial tilt on preoperative scapular-Y radiographs, and patient-reported outcome measures at the preoperative and postoperative visits. In addition, starting at 6 months postoperative, patients were asked if they could perform pushups defined as at least 10 repetitions. At the final follow-up, we collected the number of pushups patients were able to perform. Results: Thirty-two consecutive patients underwent APCLR with a mean follow-up of 26 months (range, 12-41). Significant improvement from preoperative to 2 years postoperative was demonstrated in Subjective Shoulder Value (50-85), VAS (6-2.5), American Shoulder and Elbow Surgeons (48 to 83), and Western Ontario Shoulder Instability (WOSI) (1437-777), P = .001. The recurrent instability rate was 3/32 (9%). Patients with PAH > 23 (N = 17) had a recurrent instability rate of 18% (3/17) versus PAH ≤ 23 (N = 15) 0% (0/15), worse WOSI scores (P = .41), and a lower number of pushups (P = .48). The percentage of patients reporting the ability to perform pushups was (6 months/1 year/2 years) (50%/78%/95%). The mean number of pushups reported at the final follow-up was 33 (range, 1-60). Discussion: Following APCLR, approximately 50% of patients resume pushups at 6 months postoperatively, and 80% return at 1 year. Patients reported performing a mean of 33 pushups following APCLR at the final follow-up. Patients with a PAH greater than 23 on preoperative scapular-Y radiographs had a higher rate of recurrent posterior instability, worse WOSI scores, and lower return to pushups; however, the results did not meet statistical significance. Therefore, future larger studies are needed to determine if posterior acromial morphology is independently associated with worse outcomes and increased recurrent instability rates following APCLR.

Radius of curvature of the radial head matches the capitellum: a magnetic resonance imaging analysis.

Background: The purpose of this study is to utilize elbow magnetic resonance imaging (MRI) to compare the radius of curvature (ROC) of the radial head peripheral cartilaginous rim and the cartilage contour of the capitellum to evaluate if the radial head could be a suitable osteochondral autograft for capitellar pathology. Methods: All patients who underwent an MRI of the elbow over a three-year period were reviewed. Patients with the following diagnoses were excluded: osteochondritis dissecans, osteomyelitis, tumor, and osteoarthritis. The radius of curvature of the radial head (RhROC) was measured on the axial oblique MRI sequence. The radius of curvature of the capitellum (CapROC) was measured on sagittal oblique MRI sequences, the width of the articular surface of the capitellum on coronal MRI sequences and the radial head height (RhH) and capitellar vertical height on sagittal oblique sequences. All measurements were obtained at the midpoint of the radiocapitellar joint. Spearman's coefficient was used to assess the correlation between ROC measurements. Results: Eighty-three patients were included with a mean age of 43 +/- 17 years (57 males and 26 females, 51 right and 32 left elbows). The median RhROC and CapROC measurements were 12.3 mm (interquartile range [IQR] 1.6) and 11.9 mm (IQR 1.7), respectively. The median difference was 0.3 mm (IQR = 0.6; CI 95% = [0.24, 0.46]; P < .001). A strong positive correlation was found between RhROC and CapROC (ρ = 0.89; r2 = 0.819; P < .001). Ninety-four percent (78/83) of patients had a median difference between the RhROC and CapROC of less than or equal to 1 mm, and 63% (52/83) were within 0.5 mm. The inter-rater and intra-rater reliability for RhROC and CapROC was good, intraclass correlation coefficient (ICC) = 0.89, ICC = 0.87, and ICC = 0.96, ICC = 0.97, respectively. RhH was 10.6 ± 1.3 mm, and the width of the articular surface of the capitellum was found to be 13.8 ± 1.6 mm. Conclusion: The ROC of the convex peripheral cartilaginous rim of the radial head is similar to the ROC of the capitellum. In addition, the RhH was approximately 78% of the capitellar articular width. Based on this imaging analysis, the radial head could prove to be a robust local osteochondral autograft with a similar cartilage contour in the reconstruction of the capitellum in complex intra-articular distal humerus fractures with associated radial head fractures and in the setting of "kissing lesions" of the radiocapitellar joint. Furthermore, an osteochondral plug harvested from the "safe zone" of the peripheral cartilaginous rim of the radial head could be utilized to treat isolated osteochondral lesions of the capitellum.

Public Interest in Shoulder Platelet-Rich Plasma Injections Is Increasing: A 10-Year Google Trends Analysis.

Purpose: To quantify and analyze public interest trends in platelet-rich plasma (PRP) therapy for shoulder pathology between 2011 and 2020 using Google Trends data. Methods: Google Trends data were queried for online search data ranging from January 2011 to December 2020. Various combinations of terms related to PRP and shoulder pathology were queried. Terms related to corticosteroid therapy in association with shoulder pathology were also generated for comparative analysis. Analyses were performed regarding trends in online search volumes. Results: Linear models were generated to evaluated trends in the volume of online searches for PRP and corticosteroid therapy for shoulder pathology. For both the PRP and steroid groups, linear models showed a statistically significant increase in search volume for the period studied (P < .001). The PRP group showed a significantly greater growth rate than the steroid group (P < .001). There were no statistically significant differences in online search volume when compared between different geographic and socioeconomic locations. Conclusions: This study indicates consistently increasing public interest in PRP injections in the shoulder. The rate of online search volume growth of PRP is significantly greater than that of corticosteroid injections for the period studied. Clinical Relevance: Awareness of patient perceptions has value in informing shared decision making, aligning patient expectations, and guiding areas of future research. Each of these has an impact on patient care. Being aware of patient interest and expectations is particularly important in areas with controversial or emerging research.

Free Bone Block Procedures for Glenoid Reconstruction in Anterior Shoulder Instability.

Advances in the understanding and management of bone loss in shoulder instability have led to the development of free bone block techniques as an alternative to the Latarjet procedure. These techniques have been proposed as a theoretically safer option to Latarjet, and there is growing clinical enthusiasm in their use. The purpose of this article was to contextualize the utilization of free bone block procedures in the current treatment paradigm of anterior shoulder instability and to review the history and common types of bone autograft (eg, iliac crest, distal clavicle, scapular spine) and allograft (eg, distal tibia, preshaped blocks) techniques and approaches, as well as their clinical effectiveness and safety.

The long head of the biceps tendon: a valuable tool in shoulder surgery.

ANATOMY AND FUNCTION: The long head of the biceps tendon (LHBT) has different properties and characteristics that render it a valuable tool in the hands of shoulder surgeons. Its accessibility, biomechanical strength, regenerative capabilities, and biocompatibility allow it to be a valuable autologous graft for repairing and augmenting ligamentous and muscular structures in the glenohumeral joint. SHOULDER SURGERY APPLICATIONS: Numerous applications of the LHBT have been described in the shoulder surgery literature, including augmentation of posterior-superior rotator cuff repair, augmentation of subscapularis peel repair, dynamic anterior stabilization, anterior capsule reconstruction, post-stroke stabilization, and superior capsular reconstruction. Some of these applications have been described meticulously in technical notes and case reports, whereas others may require additional research to confirm clinical benefit and efficacy. CONCLUSION: This review examines the role of the LHBT as a source of local autograft, with biological and biomechanical properties, in aiding outcomes of complex primary and revision shoulder surgery procedures.

Editorial Commentary: Revision Arthroscopic Bankart Is Not Recommended: The Sad Country Song We Just Can't Quit.

The approach to revision after an arthroscopic Bankart is a controversial topic. Several studies have shown an increased failure after revision compared with primary procedures, and many papers have recommended an open approach with or without bone augmentation. It seems intuitive that if an approach fails, that we ought to try a different one. And yet we do not. When facing this condition, it is far more common that we talk ourselves into performing another arthroscopic Bankart. It's relatively easy, familiar, and comforting. We find a reason to give this operation one more chance due to some patient-specific factor, like bone loss, number of anchors, or contact athlete status. Recent research shows that none of these factors matter, yet many of us find something that leads us to conclude that in our hands, with this patient, this time, the surgery will work. As data continue to emerge, the indications for this approach continue to narrow. It is becoming increasingly difficult to find a reason to go back to this operation as our best choice for the failed arthroscopic Bankart.

Shoulder Range of Motion Measurements and Baseball Elbow Injuries: Ambiguity in Scientific Models, Approach, and Execution is Hurting Overhead Athlete Health.

Elbow injuries are a significant and increasing issue in baseball. Elbow injuries account for 16% of all injuries sustained at the professional level and collegiate level. Because of the continued rise in injury rates, loss of performance value, and medical burden, sports medicine clinicians have attempted to research the causes underlying this injury epidemic in an attempt to help mitigate baseball elbow injuries. Shoulder range of motion (ROM) is the most researched clinical metric related to elbow injuries in baseball and has the greatest consensus as a viable prognostic factor specifically for medial elbow injury. Shoulder ROM is easy to measure, can be modified through stretching and manual therapy interventions, and can be easily assessed during preseason screening throughout all baseball levels. Despite a large number of studies and the widespread use of shoulder ROM in injury risk screening, current findings are unclear as to whether there is a true cause-effect relation with baseball elbow injuries. We argue that the conflicting findings revolving around the value of shoulder ROM measurements associated with baseball elbow injuries are the result of 4 gaps in the research approaches implemented to date: ambiguous research questions, mixed study populations, statistical models used, and shoulder ROM methodology. Specifically, there is a mismatch of methods, statistical models, and conclusions such as (1) investigating the association (i.e., correlation) between shoulder ROM measurements and injury and (2) investigating the cause-effect relation of shoulder ROM to baseball injuries. The purpose of this article is to detail the required scientific steps to evaluate whether preseason shoulder ROM is a potential causal factor for pitching elbow injury. We also provide recommendations to allow for future causal inferences to be made between shoulder ROM and elbow injury. This information will ultimately assist in informing clinical models of care and decision making for baseball throwers.

Survival of anterior cruciate ligament reconstructions in active-duty military populations.

PURPOSE: Anterior cruciate ligament tears and anterior cruciate ligament reconstruction (ACLR) are common in young athletes. The modifiable and non-modifiable factors contributing to ACLR failure and reoperation are incompletely understood. The purpose of this study was to determine ACLR failure rates in a physically high-demand population and identify the patient-specific risk factors, including prolonged time between diagnosis and surgical correction, that portend failure. METHODS: A consecutive series of military service members with ACLR with and without concomitant procedures (meniscus [M] and/or cartilage [C]) done at military facilities between 2008 and 2011 was completed via the Military Health System Data Repository. This was a consecutive series of patients without a history of knee surgery for two years prior to the primary ACLR. Kaplan-Meier survival curves were estimated and evaluated with Wilcoxon test. Cox proportional hazard models calculated hazard ratios (HR) with 95% confidence intervals (95% CI) to identify demographic and surgical factors that influenced ACLR failure. RESULTS: Of the 2735 primary ACLRs included in the study, 484/2,735 (18%) experienced ACLR failure within four years, including (261/2,735) (10%) undergoing revision ACLR and (224/2,735) (8%) due to medical separation. The factors that increased failure include Army Service (HR 2.19, 95% CI 1.67, 2.87), > 180 days from injury to ACLR (HR 1.550, 95% CI 1.157, 2.076), tobacco use (HR 1.429 95% CI 1.174, 1.738), and younger patient age (HR 1.024, 95% CI 1.004, 1.044). CONCLUSION: The overall clinical failure rate of service members with ACLR is 17.7% with minimum four-year follow-up, where more patients are likely to fail due to revision surgery than medical separation. The cumulative probability of survival at 4 years was 78.5%. Smoking cessation and treating ACLR patients promptly are modifiable risk factors impacting either graft failure or medical separation. LEVEL OF EVIDENCE: Level III.

The Effect of Amniotic Tissue on Spinal Interventions: A Systematic Review.

BACKGROUND: Amniotic membrane tissue has been thought to potentiate healing in many soft tissue conditions. Specifically, recent studies have shown its therapeutic potential for treatment in the setting of spinal pathologies. The purpose of this study is to thoroughly review the existing scientific literature and evidence concerning the clinical use of amniotic membrane-derived biologic agents on postoperative outcomes following spinal surgery. METHODS: A systematic review was conducted following preferred reporting items for systematic reviews and meta-analyses guidelines using PubMed, Embase, and Cochrane databases up to December 2020 to identify animal and clinical studies examining the therapeutic potential for amniotic membrane tissue in the setting of spinal pathologies (including disc herniation, prevention of epidural fibrosis, and spinal fusion). Studies were broken down into 2 categories: experimental model type and the type of amnion product being analyzed. RESULTS: A total of 12 studies (4 clinical studies and 8 studies utilizing animal models) met inclusion criteria. Additionally, the major types of amnion product were divided into cryopreserved/freeze-dried amniotic membrane, human amniotic fluid, human amniotic membrane, cross-linked amniotic membrane, and amnion-derived epithelial cells. While heterogeneity of study design precludes definitive specific results reporting, most studies showed positive benefits on healing/outcomes with amniotic augmentation. Specifically, amnion products have shown promising effects in reducing epidural adhesions and scar tissue after spine surgery, improving spinal fusion rate and postoperative pain scores, and promoting better functional outcomes after spine surgery. CONCLUSIONS: A review of the limited number of reported studies revealed a wide variety of amniotic membrane preparations, treatment regimens, and indications, which limit definitive conclusions. To date, while there is no definitive clinical proof that amniotic tissues enhance tissue repair or regeneration, the aggregate results demonstrate promising basic science and outcomes potential in spinal surgery. Further study is warranted to determine whether this application is appropriate in the clinical setting. CLINICAL RELEVANCE: This systematic review provides a summary of the existing literature regarding the use of amniotic membrane preparations, treatment regimens, and indications within spinal surgery. With the growing popularity and utilization of biologic agents such as amniotic membrane-derived products in orthopedic and neurologic surgery, this systematic review gives physicians a concise summary on the outcomes and indications associated with amniotic membrane products.

Treatment Following a First-Time Shoulder Dislocation: What Should I Do?

A first-time shoulder dislocation is a challenging topic that requires consideration of anatomic and patient-specific factors. Initial management is predicated on determining functional demands, activity level, and expectations of the patient, in addition to assessing the risk of recurrent instability. When considering surgical indications, it is imperative to understand the biomechanical implications of injury to the glenohumeral joint complex and how specific surgical procedures can restore stability. It is important to provide an overview of the current treatment algorithm for management of first-time shoulder dislocation, with a special focus on diagnosis and intervention in the young athlete.

Assessment of glenoid baseplate initial micromotion and fixation strength in reverse total shoulder arthroplasty designs using a direct shear force methodology.

Background: In a reverse total shoulder arthroplasty, the altered glenohumeral joint center of rotation subjects the glenoid baseplate to increased shear forces and potential loosening. Methods: This study examined glenoid baseplate micromotion and initial fixation strength with the application of direct shear force in a Sawbone model. The reverse total shoulder arthroplasty systems examined were the DJO Reverse® Shoulder Prosthesis, the Exactech Equinoxe® Reverse System, and the Tornier AequalisTM Reverse Shoulder Prosthesis. Specimens were cyclically tested with increasing shear loads until 150 µm of displacement between the implant and glenoid was achieved, and subsequently until failure, classified as either 1 cm of implant/glenoid displacement or fracture. Results: The average load withstood for the 150 µm threshold for DJO, Tornier, and Exactech was 460 ± 88 N, 525 ± 100 N, and 585 ± 160 N, respectively. The average total load at device failure for DJO, Tornier, and Exactech was 980 ± 260 N, 1260 ± 120 N, and 1350 ± 230 N, respectively. Discussion: The Exactech implant design trended toward requiring more load to induce micromotion at each threshold and to induce device failure, most commonly seen as inferior screw pull out. This study proposes design features that may enhance fixation and suggests little risk of initial micromotion or failure during initial post-operative recovery.