Clinical and Radiological Outcomes in Reverse Total Shoulder Arthroplasty by Inclination Angle With a Modular Prosthesis.

The influence of the humeral inclination in reverse total shoulder arthroplasty (RTSA) is not well understood. The purpose of this study was to determine outcomes and complications after RTSA with an inclination of 135° or 155° in a modular prosthesis. American Shoulder and Elbow Surgeons (ASES), visual analog scale (VAS), Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST) scores, as well as forward elevation (FE), abduction (ABD), and external rotation (ER), were assessed after a minimum 2-year follow-up. Scapular notching and radiolucency were assessed according to Sirveaux and Lévigne. A total of 121 patients with a mean age of 69.7±7.3 years were evaluated after a mean of 36.5±8 months. The inclination was set to 135° in 80.2% and to 155° in 19.8% of patients. There was no significant difference between the groups for ASES, VAS, SANE, and SST scores. The FE (P=.022) and ABD (P=.002) were significantly higher for the 155° inclination group. Complication rates were not significantly different between the groups. Scapular notching was significantly more common with a 155° inclination (P=.01), whereas humeral radiolucency was not correlated. All outcome scores improved significantly from pre- to postoperative (P≤.001). Reverse total shoulder arthroplasty leads to significant improvements in pain, range of motion, and outcome scores after mid-term follow-up. Overall, the inclination angle does not significantly affect clinical outcomes or the complication rate after RTSA at mid-term follow-up. However, an inclination of 155° shows significantly greater FE and ABD, although it results in a significantly higher rate of scapular notching. Cases with scapular notching are associated with significantly reduced mean ASES scores and ER as well as significantly higher VAS scores. [Orthopedics. 2021;44(4):e527-e533.].

Biconcave glenoids show 3 differently oriented posterior erosion patterns.

BACKGROUND: Posterior glenoid wear remains a challenge in anatomic and reverse total shoulder arthroplasty (rTSA) because of an asymmetric erosion with altered retroversion. The purpose of this study was to assess glenoid morphology and evaluate the influence of acromial orientation in posterior glenoid erosion patterns by using 3-dimensional (3D) models. MATERIAL AND METHODS: Computed tomographic (CT) shoulder scans from 3 study centers of patients awaiting rTSA between 2017 and 2018 were converted into 3D models and analyzed by 2 observers. Morphology, orientation and greatest depth of erosion, inclination, current retroversion and premorbid retroversion, surface areas of the glenoid, and external acromial orientation and posterior acromial slope were assessed. Measurements were compared between wear patterns, glenoid erosion entities, and genders. RESULTS: In the complete cohort of 68 patients (63.8 ± 10.0 years; 19 female, 49 male), a mean of 85.9° (±22.2°) was observed for the glenoid erosion orientation. Additionally, a further distinct classification of the glenoid erosion as posterior-central (PC, n = 39), posterior-inferior (PI, n = 12), and posterior-superior (PS, n = 17) wear patterns was possible. These wear patterns significantly (P < .001) distinguished by erosion orientation (PC = 86.9° ± 12.0°, PI = 116.3° ± 10.3°, PS = 62.3° ± 18.9°). The greatest depth of erosion found was 7.3 ± 2.7 mm in PC wear patterns (PC vs. PI: P = .03; PC vs. PS: n.s.; PI vs. PS: n.s.). Overall, the observed erosion divided the glenoid surface into a paleoglenoid proportion of 48% (±11%) and a neoglenoid proportion of 52% (±12%). For the complete cohort, glenoid inclination was 85.4° (±6.6°), premorbid glenoid retroversion was 80.7° (±8.1°), and current glenoid retroversion was 73.4° (±7.4°), with an estimated increase of 6.9° (±6.0°). The mean external acromial orientation was 118.2° (±8.9°), and the mean posterior acromial slope was 107.2° (±9.6°). There were no further significant differences if parameters were compared by wear patterns, entities, and gender. CONCLUSION: Three significantly differently oriented wear patterns (posterior-superior, posterior-central, and posterior-inferior) were distinguished in shoulders demonstrating posterior wear on axillary imaging. No significant differences between the observed erosion patterns or any relevant correlations were found regarding the orientation of the acromion.

Glenoid version is associated with different labrum tear patterns in shoulder instability.

BACKGROUND: Previous studies have evaluated glenoid version as a risk factor for anterior and posterior shoulder instability. However, the association of glenoid version with combined anterior-inferior-posterior (>180°) labrum injuries is unknown. The purpose of the present study was to investigate various parameters of glenoid morphology, including version, in >180° labral tears and to compare these values with isolated anterior and isolated posterior tears. METHODS: Magnetic resonance imaging studies from a consecutive series of shoulder instability patients were reviewed by 3 independent observers to measure the parameters of glenoid morphology including superior-inferior and anterior-posterior diameter, diameter ratio, glenoid version using the glenoid vault method, and percentage of glenoid bone loss using the best-fit circle method. These parameters were compared between patients with anterior (group 1), posterior (group 2), and >180° labral tears (group 3). Interobserver reliability coefficients were calculated for all measurements assessed. RESULTS: There were statistically significant differences for all group comparisons regarding the glenoid version, with group 2 having the most retroversion (19.9° ± 4.71°) followed by group 3 (14.21° ± 4.59°) and group 1 (11.24° ± 5.3°). Group 3 showed the lowest amount of glenoid bone loss; however, the group differences did not reach statistical significance. There was also no statistically significant group difference for the other measured parameters. Interobserver reliability was in the good to excellent range for all measurements. CONCLUSIONS: Combined anterior-inferior-posterior labral tears are associated with an increased amount of glenoid retroversion compared with isolated anterior labral tears. Isolated posterior labral tears have the largest amount of glenoid retroversion of all tear patterns.

Does quality of life influence retear rate following arthroscopic rotator cuff repair?

BACKGROUND: The primary objective was to assess whether a patient's early postoperative quality of life (QOL) correlates with the retear rate following single-tendon double-row rotator cuff repair. METHODS: We performed a secondary analysis of a randomized clinical trial of 58 patients who underwent single-tendon arthroscopic rotator cuff repair of full-thickness tears performed by a single surgeon. Patients were randomized to an early- or delayed-motion protocol. At 6 months, all patients underwent magnetic resonance imaging to assess whether the rotator cuffs were intact or retorn. QOL was assessed preoperatively and at 3 weeks, 6 weeks, 12 weeks, 6 months, and 12 months postoperatively using the Western Ontario Rotator Cuff (WORC) index. RESULTS: After 6 months of rehabilitation, 41 patients (71%) had intact rotator cuff repairs whereas 17 (29%) had full-thickness tears. Patients with torn rotator cuffs at 6 months postoperatively had significantly lower WORC scores at 6 weeks postoperatively (P = .041). Patients with greater improvements in QOL perioperatively (preoperative WORC score minus 6-week postoperative WORC score > 264.5) were more likely to have full-thickness tears by 6 months postoperatively. Compliant patients assigned to the delayed-motion protocol had a failure rate of 11% (2 of 19) compared with 38% (15 of 39) in the noncompliant and early-motion protocol patients (P < .01). Overall, patients who were noncompliant with the shoulder immobilizer were 8.2 times more likely to have a failed repair on magnetic resonance imaging (P = .01). CONCLUSIONS: Patients with better QOL shortly after arthroscopic rotator cuff repair were more likely to have retears by 6 months.

Clinical Outcomes After Biceps Tenodesis or Tenotomy Using Subpectoral Pain to Guide Management in Patients With Rotator Cuff Tears.

PURPOSE: To assess whether preoperative subpectoral tenderness in patients with rotator cuff tears was associated with arthroscopic findings of tendinopathy of the long head of the biceps, as well as whether they had resolution of their subpectoral tenderness postoperatively after tenodesis or tenotomy. METHODS: Patients presenting between 2011 and 2016 undergoing arthroscopic rotator cuff repair were evaluated preoperatively with the subpectoral biceps test (SBT). This test is performed with the arm adducted and internally rotated to allow palpation of the biceps as it courses under the pectoralis major tendon. Preoperative SBT findings determined operative management with either tenodesis or tenotomy during rotator cuff repair. Patients were followed up postoperatively to assess resolution of subpectoral tenderness with a repeated SBT. Preoperative and postoperative Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons, and Constant-Murley scores were recorded in all patients. RESULTS: A total of 128 patients were enrolled in the study, with a mean age of 58 years (range, 33-82 years). Patients with a positive preoperative SBT (n = 68) had significantly lower SANE and Constant-Murley scores preoperatively (P < .01) than patients with a negative SBT (n = 60). All patients with a positive preoperative SBT underwent either tenodesis or tenotomy, with 94% of patients (n = 64) having resolution of subpectoral pain and tenderness at final follow-up. Intraoperatively, 93% of patients with a positive SBT showed gross pathologic changes in the tendon (fraying, erythema, tears, or subluxation) compared with only 65% of patients with negative preoperative examination findings (P < .01). American Shoulder and Elbow Surgeons, Constant-Murley, and SANE scores were significantly increased postoperatively in all patients (P = .02). CONCLUSIONS: In this group of patients with rotator cuff tears surgically treated with concomitant biceps tenodesis or tenotomy, 94% had resolution of their subpectoral tenderness. A positive SBT was associated with gross pathologic changes of the biceps in 93% of patients. LEVEL OF EVIDENCE: Level III, prospective comparative study.

Incidence of Posteromedial Meniscocapsular Separation and the Biomechanical Implications on the Anterior Cruciate Ligament.

PURPOSE: To report the incidence of posterior medial meniscocapsular junction (PMCJ) separation in patients with anterior cruciate ligament (ACL) injury and to evaluate its biomechanical effect on the ACL. METHODS: Three hundred thirty-seven consecutive patients undergoing isolated primary ACL reconstruction were retrospectively analyzed for PMCJ lesion. Forty-four patients were identified with PMCJ lesion and studied. Eight cadaver knees underwent biomechanical testing to determine anterior tibial displacement and anteromedial bundle ACL strain in the intact, PMCJ lesion, and PMCJ repair states at 0°, 30°, 60°, and 90° of flexion. Mixed-effects linear regression with Bonferroni correction was used for statistical analysis. RESULTS: PMCJ tear incidence with ACL disruption was 13.1%. Specimen with PMCJ tears had statistically increased anterior tibial translation at 30° (1.2 mm; P < 0.01) and statistically increased ACL strain at 30° (24%; P < 0.01) and 90° (50%; P < 0.01). With PMCJ repair, translation reduced (P > 0.05) by 12%, 18%, and 10% at 0°, 30°, and 90° of flexion, respectively. PMCJ repair reduced (P < 0.05) ACL strain by 40%, 39%, 43%, and 31% at 0°, 30°, 60°, and 90° of flexion, respectively. CONCLUSIONS: A PMCJ lesion was observed in 13% of ACL injuries. This injury contributes to increased ACL strain, and PMCJ repair markedly reduces ACL strain to preinjury levels.

Shoulder Acromioclavicular and Coracoclavicular Ligament Injuries: Common Problems and Solutions.

Injuries to the acromioclavicular joint and coracoclavicular ligaments are common. Many of these injuries heal with nonoperative management. However, more severe injuries may lead to continued pain and shoulder dysfunction. In these patients, surgical techniques have been described to reconstruct the function of the coracoclavicular ligaments to provide stable relationship between the clavicle and scapula. These surgeries have been fraught with high complication rates including clavicle and coracoid fractures, infection, loss of reduction and fixation, hardware migration, and osteolysis. This article reviews common acromioclavicular and coracoclavicular repair and reconstruction techniques and associated complications, and provides recommendations for prevention and management.

Open subpectoral biceps tenodesis in patients over 65 does not result in an increased rate of complications.

BACKGROUND: Long head biceps tendon pathology is a common cause of anterior shoulder pain and is often associated with other shoulder conditions, such as rotator cuff tears and osteoarthritis. It is well accepted that older patients are at increased risk for major and minor peri- and postoperative complications. The purpose of this study is to investigate patients over 65 years old who underwent subpectoral biceps tenodesis and compare the complication rates of this group to those of patients younger than 65 years old. The hypothesis is, that there would be no difference in complication rates and that clinical outcome scores for patients over 65 were satisfying and showed improvements over time. METHODS: There were 337 patients who underwent open subpectoral biceps tenodesis, between January 2005 and June 2015, 23 were identified as being over the age of 65 with a minimum follow up of 12 months. All patients over the age of 65 were evaluated pre- and postoperatively using Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES), Constant-Murley (CM) and Single Assessment Numeric Evaluation (SANE). Intraoperative and postoperative adverse events (fracture, infection, wound opening, rupture/failure and neurovascular injuries) related to the tenodesis procedure and to the surgery itself were collected from all 337 patients in a routine postoperative follow-up. RESULTS: The under 65 group (range 27-64 years) at an average follow up (FU) of 30 months (range 12-91 months) showed a 5.4% (17 out of 314) post-operative complication rate related to the subpectoral tenodesis, whereas the group over 65 (range 65-77 years) at an average follow up of 33 months (range 12-79 months) showed an 8.7% (2 out of 23) complication rate. CONCLUSION: This study demonstrates that in patients over the age of 65, biceps tenodesis is a successful procedure when performed for biceps tendinopathy and concomitantly with other surgical procedures of the shoulder, and does not result in an increased rate of complications when compared to a group of patients under the age of 65.

Patellofemoral Contact Pressures After Patellar Distalization: A Biomechanical Study.

PURPOSE: To measure the patellofemoral contact pressure in early flexion after a tibial tubercle distalization osteotomy. METHODS: Ten matched-pair fresh-frozen cadaveric knees were studied. The average Blackburne-Peel ratio of the native knees was 0.91. The knees were placed on a testing rig, with a fixed femur and tibia mobile through 90° of flexion. Individual quadriceps heads and the iliotibial band were separated and loaded with 205 N in anatomic directions using a weighted pulley system. A straight tubercle distalization osteotomy of 1 cm was performed and fixed with screws, with and without a lateral release. Patellofemoral contact pressures were measured at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of flexion using pressure-sensitive films on the medial trochlea and lateral trochlea. Contact force, area, and pressure were measured in the following states: (1) in the native knee, (2) after distalization, and (3) after distalization with lateral release. RESULTS: The average Blackburne-Peel ratio after distalization was 0.64. Tibial tubercle distalization resulted in a 6-fold increase in mean contact pressure at 0° (0.15 MPa vs 0.90 MPa, P < .001) and a 55% increase at 10° of flexion (0.70 MPa vs 1.09 MPa, P = .02). Mean contact pressure was similar from 20° to 90° of flexion (P > .1). After distalization, the total contact area was significantly higher at 0° of flexion (17.7 mm2 vs 58.4 mm2, P = .02). Lateral release after distalization did not significantly change contact pressure (P > .21). CONCLUSIONS: Our results suggest that patella baja, as a result of excessive patellar distalization, can cause increased patellofemoral contact pressures during early flexion at 0° and 10°. No changes were seen in contact pressure from 20° to 90°. CLINICAL RELEVANCE: Care should be taken to prevent excessive distalization of the patella to avoid patella baja and increased patellofemoral contact pressures during early flexion.

Pectoralis Major Repair: A Biomechanical Analysis of Modern Repair Configurations Versus Traditional Repair Configuration.

BACKGROUND: Pectoralis major (PM) ruptures are increasingly common, and a variety of surgical techniques have been described. However, tested techniques have demonstrated diminished strength with inadequate restoration of the footprint and suture failure at relatively low loads. Purpose/Hypothesis: The purpose was to biomechanically compare PM transosseous suture repair (current gold standard) to modern PM repair techniques that use larger caliber sutures, suture tape, and unicortical button fixation (UBF). The null hypothesis was that there would be no mechanical difference between repair techniques and no difference in the amount of footprint restoration. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-four fresh-frozen cadaveric shoulders controlled for age and bone mineral density were randomized equally to 4 groups: (1) UBF, suture tape; (2) UBF, No. 5 suture, suture tape; (3) bone trough with No. 2 suture; and (4) native PM tendon group; all groups were tested to failure. The specimens were tested under cycling loads (10 N to 125 N) with a final load-to-failure test at 1 mm/s. Failure modes were classified by location and cause of rupture based on optical markers, while tendon footprint length was measured to determine amount of footprint restoration. RESULTS: For fixation strength, the mean peak load was significantly greater in the native tendon (1816 ± 706 N) versus UBF/No. 5 suture/suture tape (794 ± 168 N), UBF/suture tape (502 ± 201 N), and bone trough (492 ± 151 N) ( P < .001 for all). UBF/No. 5 suture/suture tape featured the lowest displacement superiorly (1.09 ± 0.47 mm) and inferiorly (1.14 ± 0.39 mm) with a significant difference compared with bone trough. With regard to tendon footprint reapproximation, cortical button fixation best approximated native tendon footprint length versus bone trough. CONCLUSION: Based on peak failure load, the UBF/No. 5 suture/suture tape construct demonstrated 61% greater construct strength than a traditional bone trough technique. Moreover, displacement after cyclic loading was by far smallest in the UBF/No. 5 suture/suture tape construct. Therefore, repair constructs with larger caliber suture and suture tape provide a measurable improvement in construct strength versus traditional PM repair techniques in a biomechanical model and may be advantageous for repair. CLINICAL RELEVANCE: Cortical button fixation with larger caliber suture and suture tape allows for a significantly better PM repair than more traditional techniques at the time of surgery, which may ultimately result in improved clinical outcomes if implemented in surgical practice.

Headless Compression Screw Versus Kirschner Wire Fixation for Metacarpal Neck Fractures: A Biomechanical Study.

PURPOSE: This study aimed to determine the biomechanical stability of headless compression screws in the fixation of metacarpal neck fractures and to compare them with another common, less invasive form of fixation, K-wires. The hypothesis was that headless compression screws would show higher stiffness and peak load to failure than K-wire fixation. METHODS: Eight matched-paired hands (n = 31), using the ring and little finger metacarpals, had metacarpal fractures simulated at the physeal scar. Each group was stabilized with either a 3.5-mm headless compression screw or 2 0.045-in (1.1-mm) K-wires. Nineteen metacarpals were tested in 3-point bending and 12 in axial loading. Peak load to failure and stiffness were calculated from the load displacement curve. Bone mineral density was recorded for each specimen. RESULTS: Bone mineral density was similar in the 2 groups tested for 3-point bending and axial loading. Stiffness was not significantly different in 3-point bending for headless compression screws and K-wires (means, 141.3 vs 194.5 N/mm) but it was significant in axial loading (means, 178.0 vs 111.6 N/mm). Peak load to failure was significantly higher in headless compression screws in 3-point bending (means, 401.2 vs 205.3 N) and axial loading (means, 467.5 vs 198.3 N). CONCLUSIONS: Compared with K-wires, headless compression screws for metacarpal neck fractures are biomechanically superior in load to failure, 3-point bending, and axial loading. CLINICAL RELEVANCE: Headless compression screws demonstrate excellent biomechanical stability in metacarpal neck fractures. In conjunction with promising clinical studies, these data suggest that headless compression screws may be an option for treating metacarpal neck fractures.

First Metatarsophalangeal Contact Properties Following Proximal Opening Wedge and Scarf Osteotomies for Hallux Valgus Correction: A Biomechanical Study.

BACKGROUND: Proximal opening wedge osteotomy (POWO) is an established procedure for moderate to severe hallux valgus. A common concern of this procedure is that it results in lengthening of the first metatarsal, which could cause increased intra-articular pressure of the first metatarsophalangeal joint (MTP) and may ultimately lead to arthritis because of these altered mechanics. The purpose of this study was to use a cadaveric model to compare intra-articular pressures and articulating contact properties of the MTP joint following either scarf osteotomy or POWO. METHODS: Fresh-frozen cadaveric below-knee specimens with pre-existing hallux valgus (n = 12) and specimens without hallux valgus (n = 6, control group) were used. The hallux valgus specimens were stratified into 2 groups (n = 6 each): POWO or scarf osteotomy. The groups were matched based on the degree of deformity. Peak intra-articular pressure, force, and area were measured in all normal, preoperative, and postoperative specimens with a simulated weightbearing model. These measurements were made with a pressure transducer placed within the first MTP joint. RESULTS: Postoperatively POWO group had slightly higher contact forces and pressures compared to the scarf group and lower contact forces and pressures than those of the normal group but were not statistically significant ( P > .05). Normal specimens had higher intra-articular force, pressure, and area than postoperative specimens but the difference was not found to be significant. First metatarsal lengthening was found in both the scarf and POWO specimens; however, neither increase was found to be significant ( P > .05). CONCLUSION: The results from this study show that after operative correction, contact properties of the fist MTP joint among normal, POWO, and scarf osteotomy groups revealed no significant differences. First MTP joints in those with hallux valgus had significantly lower contact force and pressure compared to those without hallux valgus. CLINICAL RELEVANCE: With little long-term outcomes of proximal opening wedge osteotomy, this study will help predict the possibility of future MTP joint arthritis.

The Influence of Trocar Fenestration and Volume on Connective Tissue Progenitor Cells (Stem Cells) in Arthroscopic Bone Marrow Aspiration From the Proximal Humerus.

PURPOSE: To evaluate the number of connective tissue progenitor cells (CTPs) and nucleated cells obtained during bone marrow aspiration (BMA) from the proximal humerus using either a fenestrated or a nonfenestrated trocar and determine differences in varying amounts of aspiration volume. The first hypothesis was that the number of CTPs extracted with the fenestrated trocar would be greater due to its potential to extract more cells through its fenestrations. The second hypothesis was that using consecutive aspirations with either trocar would provide a consistent number of CTPs and nucleated cells throughout the aspiration with no significant decrease of cells at the end. METHODS: Patients were eligible for inclusion if they underwent primary or revision arthroscopic rotator cuff surgery, were between 18 and 75 years of age, and signed the informed consent. Between January 2011 and September 2013, 24 patients underwent BMA from the proximal humerus during arthroscopic surgery. They were grouped according to which of 3 different trocars were used for aspiration: (1) nonfenestrated, (2) fenestrated trocar A, and (3) fenestrated trocar H. Four consecutive 12 mL double syringes were used for each aspiration: 1 (0-12 mL), 2 (12-24 mL), 3 (24-36 mL), and 4 (36-48 mL). One milliliter was removed from each syringe (nonconcentrated BMA). The remainder of the BMA was then spun using a centrifuge. BMA and concentrated BMA were brought to the laboratory, counted for nucleated cells (million cells/mL BMA) and cultured for 7 days to obtain colony-forming units (CTPs/million cells). RESULTS: No significant differences were observed in tubes 1 to 4 in the number of nucleated cells in the nonconcentrated and concentrated BMA using the nonfenestrated trocar compared with the fenestrated trocars A and H (all P > .05), except for concentrated BMA tube 3 (P = .014) and tube 4 (P = .003). Nonconcentrated and concentrated BMA from tubes 1 to 4 had a significantly higher CTP prevalence using the nonfenestrated trocar compared with the fenestrated trocars A and H (all P < .05). Most of the times the first tube of each aspiration showed a significantly greater amount of cells and a greater CTP prevalence compared with tubes 2, 3, and 4. CONCLUSIONS: Aspiration from the proximal humerus with the nonfenestrated trocar during BMA was associated with higher prevalence of CTPs, suggesting that more CTPs can be obtained using a nonfenestrated trocar. Furthermore, CTPs can be obtained through all consecutive aspirations with a greater amount in the first tubes. LEVEL OF EVIDENCE: Level II, prospective comparative study.

A Biomechanical Analysis of Different Clavicular Tunnel Diameters in Anatomic Acromioclavicular Ligament Reconstruction.

PURPOSE: To evaluate the biomechanical stability of a tendon-to-clavicle bone interface fixation of a graft in revision acromioclavicular reconstruction. METHODS: Fifteen fresh-frozen cadaveric shoulders were used. All specimens underwent bone density evaluation. For the primary reconstruction, a 5-mm semitendinosus allograft was inserted into a 5-mm bone tunnel at 25 and 45 mm from the lateral end of the clavicle using a 5.5 × 8-mm PEEK (polyether ether ketone) tenodesis screw. Each single graft was fixed in a cryo-clamp and cyclically loaded from 5 to 70 N for 3,000 cycles, followed by load-to-failure testing at a rate of 120 mm/min to simulate the revision case. To simulate tunnel widening, the tunnels of the revision series were over-drilled with an 8-mm drill, and a 5-mm semitendinosus graft with an 8 × 12-mm PEEK tenodesis screw was inserted. Biomechanical testing was then repeated. RESULTS: The bone mineral density analysis showed a significantly higher density at the 45-mm hole compared with the 25-mm hole (P = .001). The ultimate load to failure increased from the 5.5-mm screw to the 8-mm screw at the 45-mm hole position (P = .001). There was no statistically significant difference at the 25-mm hole position (P = .934). No statistical significance for graft elongation comparing the 5.5-mm screw and the 8-mm screw at the 25-mm (P = .156) and 45-mm (P = .334) positions could be found. CONCLUSIONS: Comparable biomechanical stability for the tendon-to-bone interface fixation in different clavicular tunnel diameters simulating primary and revision reconstruction was achieved. CLINICAL RELEVANCE: There is a lack of literature regarding revision acromioclavicular joint reconstruction, but our biomechanical results show comparable stability to primary reconstruction. These data provide support for the use of anatomic acromioclavicular ligament reconstruction in revision cases.

A Systematic Review of Meta-analyses Published in Arthroscopy: The Journal of Arthroscopic and Related Surgery.

PURPOSE: To determine whether the number of meta-analyses published by Arthroscopy: The Journal of Arthroscopic and Related Surgery has increased from the inception of the Journal through 2014. METHODS: A literature search of the Journal's Web site and Medline was carried out. All studies described as a "meta-analysis" as well as systematic reviews that pooled data were included. The number of published meta-analyses was calculated and summarized by year of publication, region, topic, and level of evidence. RESULTS: The Journal's Web site search resulted in 517 citations for review, and the Medline search resulted in 400. After the results of each search were combined and duplicates were removed, a total of 60 studies were included in this review. The first published meta-analysis appeared in 2001. Of the 60 meta-analyses, 36 (60%) were published between 2013 and 2014. In light of the increase in the number of publications, a review of the design and conduct of a meta-analysis is presented in a straightforward question-and-answer format. CONCLUSIONS: The number of meta-analyses appearing in Arthroscopy has increased over the past 2 decades. This increase highlights the importance of developing an understanding of the premise and components of a meta-analysis to allow the reader to critically appraise these studies. LEVEL OF EVIDENCE: Level IV, systematic review of Level I through IV meta-analyses.