Combined Medial Collateral Ligament Reconstruction and Polyethylene Exchange for Valgus Instability Following Total Knee Arthroplasty.

Valgus instability can occur after total knee arthroplasty (TKA) due to traumatic medial collateral ligament (MCL) injury, component malpositioning, or progressive ligamentous laxity. Although revision TKA with exchange of the polyethylene to a varus-valgus-constrained liner can reduce laxity due to MCL insufficiency, isolated liner exchange in the setting of collateral ligament insufficiency may lead to greater strain at the cement-bone or implant-cement interface and possibly a greater rate of aseptic loosening. Anatomic MCL reconstruction can be performed in conjunction with liner exchange to restore stability and reduce strain compared with liner exchange alone. The purpose of this Technical Note is to describe a technique for MCL reconstruction and liner exchange for treatment of valgus instability after TKA.

Biomechanical comparison of ulnar collateral ligament reconstruction with single-tunnel proximal suspensory fixation versus modified docking technique.

Background: Despite technical advancement, elbow ulnar collateral ligament (UCL) reconstruction is a challenging procedure due to the limitations regarding the challenging tunnel placement and potential injury to the ulnar nerve. Furthermore, current techniques for reconstruction and repair are inferior functionally and biomechanically when compared to native UCL tissue. A modified docking technique using a single-tunnel proximal suspensory fixation may reduce complications and potentially provide a technique for UCL reconstruction that is biomechanically superior. Decreasing the number of bone tunnels decreases the number of places that bone tear through could occur. The purpose was to evaluate and compare the biomechanical performances for 2 elbow UCL reconstruction techniques: (1) standard docking technique (SD) and (2) a proximal single tunnel (PST) technique using a suspensory fixation. We hypothesized that the PST technique would be biomechanically superior to the SD technique. Methods: Twelve matched pairs of cadaveric elbows were dissected and fixed at 70 degrees for biomechanical testing. Gracilis grafts were used for a docking reconstruction and the modified reconstruction with a PST suspensory fixation. A cyclic valgus torque protocol was used to precondition specimens for either reconstruction technique and the ulnohumeral gapping was then assessed. Following gapping measurements, postsurgical specimens underwent a valgus rotation applied at a rate of 5°/s until the anterior band of the UCL failed or fracture occurred. Ultimate load to failure, stiffness, and mode of failure were recorded. Results: There were no statistical differences between the two groups. Mean rotational stiffness of the SD (2.3 ± 0.6 Nm/deg) compared to the PST (1.9 ± 0.7 Nm/deg) (P = .41) and mean ultimate failure torque of the SD (30.5 ± 9.2 Nm) compared to the PST (30.9 ± 8.6 Nm) (P = .86) were similar. There was also no statistically significant difference (P = .83) when comparing the native UCL ulnohumeral gapping (6.0 ± 2.0 mm) to the mean ulnohumeral gapping of the SD reconstruction (6.0 ± 1.8 mm). Conclusions: This study compares the biomechanical strength of elbow UCL reconstructions performed using the SP technique to that of a PST technique. Among all tested parameters, including ultimate failure torque, stiffness, and ulnohumeral gapping, there were no statistically significant differences between the 2 techniques.

In situ repair of segmental loss posterior lateral meniscal root tears outperforms meniscofemoral ligament imbrication in the ACL reconstructed knee.

PURPOSE: The purpose of this study was to compare the biomechanical effect of in-situ repair of posterior lateral meniscal root (PLMR) tear with segmental meniscal loss, with and without meniscofemoral ligament (MFL) imbrication, on anterior cruciate ligament (ACL) graft force and knee joint kinematics. METHODS: Ten fresh-frozen cadaveric knee specimens underwent kinematic evaluation in five states: 1) Native, 2) ACLR, 3) Segmental PLMR loss, 4) In-situ PLMR repair, and 5) MFL augmentation. Kinematic evaluation consisted of five tests, each performed at full extension and at 30° of flexion: 1) Anterior drawer, 2) Internal Rotation, 3) External Rotation, 4) Varus, and 5) Valgus. Additionally, a simulated pivot shift test was performed. Knee kinematics and ACL graft force were measured. RESULTS: PLMR tear did not significantly increase ACL graft force in any test. However, PLMR repair significantly reduced ACL graft force compared to the ACLR alone (over constraint -26.6 N, p = 0.001). PLMR tear significantly increased ATT during the pivot shift test (+ 2.7 mm, p = 0.0001), and PLMR repair restored native laxity. MFL augmentation did not improve the mechanics. CONCLUSIONS: In-situ PLMR repair eliminated pivot shift laxity through ATT and reduced force on the ACL graft, indicating that this procedure may be ACL graft-protective. MFL augmentation was not shown to have any effect on graft force or knee kinematics and untreated PLMR tears may place an ACL graft at higher risk. This study suggests concomitant repair to minimize additional forces on the ACL graft.

Arthroscopic Rotator Cuff Repair and Subpectoral Biceps Tenodesis in the Lateral Decubitus Position.

Arthroscopic rotator cuff repair can be performed with the patient in the beach-chair or lateral decubitus position. Patient positioning in shoulder arthroscopy is a critical step in surgical preparation and remains a debated topic. The lateral decubitus position is a reliable, safe, and effective position in which to perform nearly all types of shoulder arthroscopic procedures. The purpose of this Technical Note is to describe our preferred technique for performing arthroscopic rotator cuff repair with the patient in the lateral decubitus position, which portends several advantages, such as improved visualization of the glenohumeral space, ergonomic positioning, a low risk of cerebral hypoperfusion, and a shorter operating time.

Shoulder Pathology on Magnetic Resonance Imaging in Asymptomatic Elite-Level Rock Climbers.

BACKGROUND: The prevalence of findings on shoulder magnetic resonance imaging (MRI) is high in asymptomatic athletes of overhead sports. PURPOSE/HYPOTHESIS: The purpose of this study was to determine the prevalence of atypical findings on MRI in shoulders of asymptomatic, elite-level climbers and to evaluate the association of these findings with clinical examination results. It was hypothesized that glenoid labrum, long head of the biceps tendon, and articular cartilage pathology would be present in >50% of asymptomatic athletes. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 50 elite climbers (age range, 20-60 years) without any symptoms of shoulder pain underwent bilateral shoulder examinations in addition to dedicated bilateral shoulder 3-T† MRI. Physical examinations were performed by orthopaedic sports medicine surgeons, while MRI scans were interpreted by 2 blinded board-certified radiologists to determine the prevalence of abnormalities of the articular cartilage, glenoid labrum, biceps tendon, rotator cuff, and acromioclavicular joint. RESULTS: MRI evidence of tendinosis of the rotator cuff, subacromial bursitis, and long head of the biceps tendonitis was exceptionally common, at 80%, 79%, and 73%, respectively. Labral pathology was present in 69% of shoulders, with discrete labral tears identified in 56%. Articular cartilage changes were also common, with humeral pathology present in 57% of shoulders and glenoid pathology in 19% of shoulders. Climbers with labral tears identified in this study had significantly increased forward elevation compared with those without labral tears in both active (P = .026) and passive (P = .022) motion. CONCLUSION: The overall prevalence of intra-articular shoulder pathology detected by MRI in asymptomatic climbers was 80%, with 57% demonstrating varying degrees of glenohumeral articular cartilage damage. This high rate of arthritis differs significantly from prior published reports of other overhead sports athletes.

Medial Biplanar Closing-Wedge Distal Femoral Osteotomy Using an Articulated Tensioning Device for Controlled Osteotomy Closure.

Isolated lateral compartment arthritis or focal chondral defects in the setting of genu valgum in young, active individuals can be treated with a varus-producing distal femoral osteotomy with or without cartilage treatment. Both medial closing-wedge and lateral opening-wedge techniques have been described, with neither demonstrating clear superiority. The objective of this Technical Note is to describe a technique of biplanar medial opening-wedge with controlled reduction using an articulated tensioning device to achieve a safe, reproducible result.

Does dual plating clavicle fractures increase the risk of refracture after hardware removal? A biomechanical investigation.

BACKGROUND: Dual orthogonal plating of midshaft clavicle fractures is increasingly used for osteosynthesis. The risk of refracture after hardware removal remains unknown. The purpose of this study was to compare the torsional and 3-point bending loads to failure of the clavicle following removal of single-plane, superior 3.5-mm plate fixation vs. dual orthogonal plating 2.7-mm constructs. METHODS: This study used 12 pairs of clavicles (N = 24) harvested from cadaveric specimens with a mean age at death of 56.5 years (range, 46-65 years). One clavicle from each pair was randomly assigned to either superior plating (SP, n = 12) or double plating (DP, n = 12). For SP, a superior 3.5-mm plate was used as a template to drill 3 bicortical 2.8-mm holes medial and lateral to the center of the clavicle. For DP, two 2.7-mm plates were used as a template to drill 4 bicortical 2.0-mm holes medial and lateral to the center of the clavicle. Clavicle pairs were randomly and evenly distributed to undergo either 3-point bending (n = 12) or posterior torsional loading (n = 12). Cyclic loading was performed, followed by load-to-failure testing. Stiffness, displacement at failure, load to failure, and failure mode were assessed and compared between SP and DP constructs. RESULTS: No significant differences between the SP and DP groups were observed for stiffness (768.2 ± 281.3 N/mm vs. 785.5 ± 315.0 N/mm, P = .872), displacement at failure (8.1 ± 2.8 mm vs. 5.4 ± 1.2 mm, P = .150), and ultimate load at failure (1831.0 ± 229.6 N vs. 1842.0 ± 662.4 N, P = .964) under the condition of 3-point bending. Similarly, no significant differences between the SP and DP groups were observed for torsional stiffness (1.3 ± 0.8 N · m/° vs. 1.1 ± 0.4 N · m/°, P = .844), rotation at failure (17.3° ± 4.4° vs. 14.4° ± 1.2°, P = .205), and ultimate torque at failure (14.8 ± 6.5 N · m vs. 14.7 ± 6.9 N · m, P = .103) under the condition of posterior torsional loading. The most common mode of failure for 3-point bending testing was an oblique fracture (7 of 12 clavicles, 58.3%), with no significant difference between groups (3 of 6 in SP group [50%] vs. 4 of 6 in DP group [66.7%], P > .999). The most common mode of failure with posterior torsional loading was a spiral fracture (10 of 12 clavicles, 83.3%), with no significant difference between groups (4 of 6 in SP group [66.7%] vs. 6 of 6 in DP group [100%], P = .455). CONCLUSION: Following clavicle plate removal of either DP or SP, there is no statistically significant difference in the amount of force, under the condition of 3-point bending or torsional loading, required to fracture the diaphyseal clavicle in vitro.

Limited Predictive Value of the Instability Severity Index Score: Evaluation of 217 Consecutive Cases of Recurrent Anterior Shoulder Instability.

PURPOSE: To review the existing variables and their ability to predict recurrence of shoulder instability as it relates to the Instability Severity Index Score (ISIS), as well as evaluate any other pertinent imaging and patient history variables that may impact risk of recurrent anterior instability after arthroscopic Bankart repair. METHODS: All consecutive patients with recurrent anterior shoulder instability and who had arthroscopic instability repair were identified. Exclusion criteria were prior surgery on the shoulder, posterior or multidirectional instability, instability caused by seizure disorder, or a rotator cuff tear. All ISIS variables were recorded (age <20 years, sport type and level, hyperlaxity, Hill-Sachs on anteroposterior external rotation radiograph, loss of glenoid contour on anteroposterior radiograph), as well as additional variables: (1) number of instability events; (2) total time of instability; (3) glenoid bone loss (GBL) percent; and (4) Hill-Sachs measures (H/L/W/D/Volume). Postoperative outcomes were assessed based on the Western Ontario Shoulder Instability Index (WOSI), Single Assessment Numeric Evaluation (SANE) scores, and American Shoulder and Elbow Surgeons (ASES) scores, and recurrent anterior instability. Regression analysis was used to determine preoperative variables that predicted outcomes and failures. RESULTS: There were 217 consecutive patients (209 male patients [96.5%], 8 female patients [3.5%]) who met the inclusion criteria and were all treated with a primary arthroscopic shoulder stabilization during a 3.5-year period (2007-2011), with a mean follow-up time of 42 months (range, 26-58). The mean age at first instability event was 23.9 years (range, 16-48 years) and the mean cumulative ISIS score for the overall group was 3.6 (range, 1-6). Outcomes were improved from mean preoperative (WOSI = 1,050/2,100; ASES = 61.0; SANE = 52.5) to postoperative (WOSI = 305/2,100; ASES = 93.5; SANE = 95.5). A total of 11.5% (25/217) of patients had evidence of recurrent instability (subluxation or dislocation). Additionally, all 25 patients who failed postoperatively also had consistently inferior ASES, SANE, and WOSI outcome scores when compared with successfully treated patients. Factors associated with failure were GBL greater than 14.5% (P < .001), total time of instability symptoms greater than 3 months (P = .03), Hill-Sachs volume greater than 1.3 cm3 (P = .02), contact sports participation (P = .05), and age 20 years or younger (P < .01). There was no correlation in outcomes with Hill-Sachs on presence of glenoid contour loss on radiograph (P = .07), participation sports, or ISIS (mean = 3.4 success vs 3.9 failure, P > .05). CONCLUSIONS: At a mean follow-up of 42 months was an 11.5% failure rate after arthroscopic Bankart stabilization surgery. This study shows no correlation between treatment outcome and the ISIS measure, given a mean score of 3.4 for the overall cohort with little difference identified in those who failed. However, several important parameters previously unidentified were detected including, GBL greater than 14.5%, Hill-Sachs volume greater than 1.3 cm3, and duration of instability symptoms (>3 months). The ISIS may need to be redesigned to incorporate variables that more accurately portray the actual risk of failure after arthroscopic stabilization, including quantification of both glenoid and humeral head bone loss. LEVEL OF EVIDENCE: III (Retrospective Case Series).

Quantitative and Qualitative Analyses of the Lateral Ligamentous Complex and Extensor Tendon Origins of the Elbow: An Anatomic Study.

BACKGROUND: The lateral collateral ligament complex of the elbow is important in preventing posterolateral rotary instability of the elbow. Understanding the quantitative anatomy of this ligamentous complex and the overlying extensor musculature can aid in the surgical treatment of problems affecting the lateral side of the elbow. PURPOSE: To perform qualitative and quantitative anatomic evaluations of the lateral elbow ligamentous complex and common extensor muscle origins with specific attention to pertinent osseous landmarks. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 10 nonpaired, fresh-frozen human cadaveric elbows (mean age, 42.2 years; all male) were utilized. Quantitative analysis was performed using a 3-dimensional coordinate measuring device to quantify the location of pertinent bony landmarks, tendons, and ligament footprints of the lateral side of the elbow. RESULTS: The extensor carpi radialis brevis was the only humeral footprint found to cross the radiocapitellar joint line, extending a mean 5.9 mm (95% CI, 4.7-7.0) distal to the joint line. With the elbow in full extension, the lateral ulnar collateral ligament (LUCL) humeral footprint was found 7.1 mm (95% CI, 4.7-9.4) anterior and 9.8 mm (95% CI, 8.4-11.2) distal to the lateral epicondyle and 8.6 mm (95% CI, 7.5-9.7) proximal to the radiocapitellar joint line, while the radial collateral ligament humeral footprint was found 6.6 mm (95% CI, 5.5-7.8) anterior and 5.6 mm (95% CI, 4.0-7.2) distal to the lateral epicondyle and 12.7 mm (95% CI, 11.4-14.0) proximal to the radiocapitellar joint line. The center of the ulnar attachment of the LUCL was found 1.4 mm (95% CI, 0.7-2.1) anterior and 2.4 mm (95% CI, 1.2-6.0) proximal to the supinator tubercle and 24.4 mm (95% CI, 22.7-26.1) distal to the radiocapitellar joint line. The center of the ulnar attachment of the annular ligament was found to be 17.3 mm proximal to the supinator tubercle. CONCLUSION: The current study provides measured distances of LUCL and radial collateral ligament attachments in reference to clinically relevant landmarks, which can potentially aid surgeons in performing more anatomic reconstruction or repair of the lateral ligamentous complex of the elbow.

The Saber Technique for Biceps Tenotomy.

Long head of the biceps (LHB) pathology is a prevalent cause of shoulder pain. Arthroscopic tenotomy and tenodesis are performed for treatment at increasing frequency. When LHB pathology is the only glenohumeral intra-articular pathology that needs to be addressed, and an LHB tenotomy or subpectoral LHB tenodesis is planned, it is unnecessary and potentially harmful to establish an anterior rotator interval portal. The objective of this Technical Note is to describe a minimally invasive technique for LHB tenotomy at the supraglenoid tubercle without the need for establishing an accessory portal.

Elbow Fractures.

The elbow joint consists of the humeroulnar, humeroradial, and proximal radioulnar joints. Elbow stability is maintained by a combination of static and dynamic constraints. Elbow fractures are challenging to treat because the articular surfaces must be restored perfectly and associated soft tissue injuries must be recognized and appropriately managed. Most elbow fractures are best treated operatively with restoration of normal bony anatomy and rigid internal fixation and repair and/or reconstruction of the collateral ligaments. Advanced imaging, improved understanding of the complex anatomy of the elbow joint, and improved fixation techniques have contributed to improved elbow fracture outcomes.

Alternative Management of the Capsule in the Bristow-Latarjet Procedure.

The Bristow-Latarjet procedure is considered the current gold standard for the management of anterior glenohumeral joint instability in which significant glenoid bone loss is present, and numerous techniques have been proposed for capsular management after the bony augmentation component of the procedure. These techniques for capsular management include excision of the capsule and labrum, 2-flap elevation, T-capsulotomy, or an L-shaped incision into the capsule. Capsular management during open shoulder procedures may vary among surgeons and may or may not include capsulolabral repair after the Bristow-Latarjet procedure. The purpose of this Technical Note was to illustrate an alternative approach to capsular management, focusing on the elevation of the capsulolabral complex as a sleeve along with augmentation using the coracoacromial ligament during the Bristow-Latarjet procedure in patients with anterior glenohumeral instability. The proposed technique provides the benefit of improvement in visualization to more reliably identify the ideal location for bone block placement and allows for the surgeon to perform a large inferior-to-superior capsular shift to prevent inferior subluxation or instability.

Low-Profile Dual Small Plate Fixation Is Biomechanically Similar to Larger Superior or Anteroinferior Single Plate Fixation of Midshaft Clavicle Fractures.

BACKGROUND: Limited biomechanical data exist for dual small plate fixation of midshaft clavicle fractures, and no prior study has concurrently compared dual small plating to larger superior or anteroinferior single plate and screw constructs. PURPOSE: To biomechanically compare dual small orthogonal plating, superior plating, and anteroinferior plating of midshaft clavicle fractures by use of a cadaveric model. STUDY DESIGN: Descriptive laboratory study. METHODS: The study used 18 cadaveric clavicle specimens (9 pairs total), and 3 plating techniques were studied: anteroinferior, superior, and dual. The dual plating technique used smaller diameter plates and screws (1.6-mm thickness) than the other, single plate techniques (3.3-mm thickness). Each of the 9 clavicle pairs was randomly assigned a combination of 2 plating techniques, and randomization was used to determine which techniques were used for the right and left specimens. Clavicles were plated and then osteotomized to create an inferior butterfly fracture model, which was then fixed with a single interfragmentary screw. Clavicle specimens were then potted for mechanical testing. Initial bending, axial, and torsional stiffness of each construct was determined through use of a randomized nondestructive cyclic testing protocol followed by load to failure. RESULTS: No significant differences were found in cyclical axial (P = .667) or torsional (P = .526) stiffness between plating groups. Anteroinferior plating demonstrated significantly higher cyclical bending stiffness than superior plating (P = .005). No significant difference was found in bending stiffness between dual plating and either anteroinferior (P = .129) or superior plating (P = .067). No significant difference was noted in load to failure among plating methods (P = .353). CONCLUSION: Dual plating with a smaller plate-screw construct is biomechanically similar to superior and anteroinferior single plate fixation that uses larger plate-screw constructs. No significant differences were found between dual plating and either superior or anteroinferior single plating in axial, bending, or torsional stiffness or in bending load to failure. Dual small plating is a viable option for fixing midshaft clavicle fractures and may be a useful low-profile technique that avoids a larger and more prominent plate-screw construct. CLINICAL RELEVANCE: Plate prominence and hardware irritation are commonly reported complaints and reasons for revision surgery after plate fixation of midshaft clavicle fractures. Dual small plate fixation has been used to improve cosmetic acceptability, minimize hardware irritation, and decrease reoperation rate. Biomechanically, dual small plate fixation performed similarly to larger single plate fixation in this cadaveric model of butterfly fracture.

Variations in Blood Supply From Proximal to Distal in the Ulnar Collateral Ligament of the Elbow: A Qualitative Descriptive Cadaveric Study.

BACKGROUND: The vascular supply of the ulnar collateral ligament (UCL) is unknown. Previous studies reported varying success in return-to-play rates after nonoperative management of partial UCL tears and suggested a varying healing capacity as possibly related to the location of the UCL injury. PURPOSE: To analyze the macroscopic vascular anatomy of the UCL of the elbow. STUDY DESIGN: Descriptive laboratory study. METHODS: Eighteen fresh-frozen male cadaveric elbows from 9 donors were sharply dissected 15 cm proximal to the medial epicondyle. Sixty milliliters of India ink was injected through the brachial artery of each elbow. Arms were then frozen at -10°C, radial side down, in 15° to 20° of elbow flexion. A band saw was used to section the frozen elbows into 5-mm coronal or sagittal sections. Sections were cleared for visualization with the modified Spalteholz technique. Images of the specimens were taken, and qualitative description of UCL vascularity was undertaken. RESULTS: The authors consistently found a dense blood supply to the proximal UCL, while the distal UCL was hypovascular. They also observed a possible osseous contribution to the proximal UCL from the medial epicondyle in addition to an artery from the flexor/pronator musculature that consistently appeared to provide vascularity to the proximal UCL. The degree of vascular penetration from proximal to distal in the UCL ranged from 39% to 68% of the overall UCL length, with a 49% mean length of vascular penetration of the UCL. CONCLUSION: This study found a difference in the vascular supply of the UCL. The proximal UCL was well vascularized, while the distal UCL was hypovascular. This difference in vascular supply may be a factor in the differential healing capacities of the UCL based on the location of injury. CLINICAL RELEVANCE: An improved understanding of the macroscopic vascular supply of the UCL may aid in the clinical management of partial UCL tears and suggests an indication for these treatments with respect to location of UCL injuries.

Evaluation of Endothelial and Vascular-Derived Progenitor Cell Populations in the Proximal and Distal UCL of the Elbow: A Comparative Study.

Background: Vascular-derived progenitor and endothelial cell populations (CD31, CD34, CD146) are capable of multipotent differentiation at the site of injured ligamentous tissue to aid in the intrinsic healing response. Proximal ulnar collateral ligament (UCL) tears have been reported to have better healing capability when compared with distal UCL tears. Purpose: To compare the vascular composition of the proximal and distal insertions of the anterior bundle of the UCL of the elbow via known markers of endothelial and vascular-derived progenitor cells (CD31, CD34, CD146). Study Design: Descriptive laboratory study. Methods: UCLs were harvested from 10 nonpaired fresh-frozen human cadaveric elbows and transected into proximal and distal portions. Endothelial and vascular-derived progenitor cell densities were assessed with 4 staining groups: CD31 (immunohistochemistry) and CD31/α-smooth muscle actin (α-SMA), CD34/α-SMA, and CD146/α-SMA (immunofluorescence). CD31 immunohistochemistry identified endothelial progenitor cells in the UCL. Later staining of the same slides with α-SMA demonstrated the relationship of progenitor cells to the surrounding vasculature. Fluorescent staining was quantified by calculating the proportion of positively stained nuclei versus the total number of nuclei in the proximal and distal UCL. Results: CD31+ cells were present in the proximal and distal sections of all 10 UCLs. Fluorescent staining revealed no significant differences in the ratio of CD31 to total nuclei between the distal (median, 36% [range, 23%-53%]) and proximal UCL (39% [22%-56%]) (P = .432, Wilcoxon signed-rank test). Similarly, no differences were seen between CD34 distal (39% [24%-64%]) and proximal regions (46% [28%-63%]) (P = .846, Wilcoxon signed-rank test) or CD146 distal (40% [12%-65%]) and proximal regions (40% [22%-51%]) (P ≥ .999, Wilcoxon signed-rank test). Conclusion: Analysis of UCL tissues demonstrated equal distributions of vascular endothelial and vascular-derived progenitor cell markers throughout the proximal and distal UCL. Unlike that of the medial collateral ligament of the knee, the microvascular composition of the proximal and distal UCL insertions was not different, suggesting a well-vascularized ligament throughout its course. Clinical Relevance: These findings investigate one of the possible contributors to UCL healing after injury, which may provide insight into operative and nonoperative management of UCL injuries in the future. This study also indicates that reasons other than differences in progenitor cell density alone may explain the clinical healing differences seen between proximal and distal UCL tears. A better understanding of the microvascular environment and associated blood supply is warranted to understand the healing capability of the UCL.

Immediate physical therapy without postoperative restrictions following open subpectoral biceps tenodesis: low failure rates and improved outcomes at a minimum 2-year follow-up.

HYPOTHESIS: We aimed to determine patient-reported outcomes in patients undergoing open subpectoral biceps tenodesis with a dual-fixation construct who had no postoperative range-of-motion or weight-bearing restrictions. Our hypothesis was that patients without postoperative restrictions would have low failure rates with improved patient-reported outcomes. We further hypothesized that this technique would allow an earlier return to activity and similar functional outcomes when compared with those reported in the literature. METHODS: In this institutional review board-approved retrospective outcome study, we evaluated 105 patients who underwent primary open subpectoral biceps tenodesis with a bicortical suture button and interference screw construct without postoperative restrictions. The primary outcome measure was failure of the biceps tenodesis. Postoperative outcome scores included the Short Form 12 (SF-12) Physical Component Score; SF-12 Mental Component Score; American Shoulder and Elbow Surgeons total score and subscales; and Disabilities of the Arm, Shoulder and Hand score. RESULTS: A total of 98 patients (85%) were available for final follow-up at an average of 3.5 years. There were 2 failures (2.2%), at 5 weeks and 9 weeks postoperatively. Four patients underwent additional surgery unrelated to the previous tenodesis procedure. Final outcome scores indicated high levels of function, including the SF-12 Physical Component Score (mean, 51.5; SD, 7.8), SF-12 Mental Component Score (mean, 54.7; SD, 6.7), American Shoulder and Elbow Surgeons total score (mean, 89.4; SD, 14.2), and Disabilities of the Arm, Shoulder and Hand score (mean, 11.3; SD, 13.4). CONCLUSION: Open subpectoral biceps tenodesis using a dual-fixation construct with no postoperative motion restrictions resulted in excellent outcomes with a low incidence of failure.

Qualitative and Quantitative Analyses of the Dynamic and Static Stabilizers of the Medial Elbow: An Anatomic Study.

BACKGROUND: The anterior bundle of the medial ulnar collateral ligament (UCL) and the forearm flexors provide primary static and dynamic stability to valgus stress of the elbow in overhead-throwing athletes. Quantitative anatomic relationships between the dynamic and static stabilizers have not been described. PURPOSE: To perform qualitative and quantitative anatomic evaluations of the medial elbow-UCL complex with specific attention to pertinent osseous and soft tissue landmarks. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten nonpaired, fresh-frozen human cadaveric elbows (mean age, 54.1 years [range, 42-64 years]; all male) were utilized for this study. Quantitative analysis was performed with a 3-dimensional coordinate measuring device to quantify the location of pertinent bony landmarks and tendon and ligament footprints on the humerus, ulna, and radius. RESULTS: The anterior bundle of the UCL attached 8.5 mm (95% CI, 6.9-10.0) distal and 7.8 mm (95% CI, 6.6-9.1) lateral to the medial epicondyle, 1.5 mm (95% CI, 0.5-2.5) distal to the sublime tubercle, and 7.3 mm (95% CI, 6.1-8.5) distal to the joint line on the ulna along the ulnar ridge. The flexor digitorum superficialis (FDS) ulnar tendinous insertion was closely related and interposed within the anterior bundle of the UCL, overlapping with 45.6% (95% CI, 38.1-53.6) of the length of the anterior bundle of the UCL. The flexor carpi ulnaris (FCU) attached 1.9 mm (95% CI, 0.8-2.9) posterior and 1.3 mm (95% CI, 0.6-3.2) proximal to the sublime tubercle and overlapped with 20.9% (95% CI, 7.2-34.5) of the area of the distal footprint of the anterior bundle of the UCL. CONCLUSION: The anterior bundle of the UCL had consistent attachment points relative to the medial epicondyle and sublime tubercle. The ulnar limb of the FDS and FCU tendons demonstrated consistent insertions onto the ulnar attachment of the anterior bundle of the UCL. These anatomic relationships are important to consider when evaluating distal UCL tears both operatively and nonoperatively. Excessive stripping of the sublime tubercle should be avoided during UCL reconstruction to prevent violation of these tendinous attachments. CLINICAL RELEVANCE: The findings of this study enhance the understanding of valgus restraint in throwing athletes and provide insight into the difference in nonoperative outcomes between proximal and distal tears of the UCL.

Intraarticular arthrofibrosis of the knee alters patellofemoral contact biomechanics.

BACKGROUND: Arthrofibrosis in the suprapatellar pouch and anterior interval can develop after knee injury or surgery, resulting in anterior knee pain. These adhesions have not been biomechanically characterized. METHODS: The biomechanical effects of adhesions in the suprapatellar pouch and anterior interval during simulated quadriceps muscle contraction from 0 to 90° of knee flexion were assessed. Adhesions of the suprapatellar pouch and anterior interval were hypothesized to alter the patellofemoral contact biomechanics and increase the patellofemoral contact force compared to no adhesions. RESULTS: Across all flexion angles, suprapatellar adhesions increased the patellofemoral contact force compared to no adhesions by a mean of 80 N. Similarly, anterior interval adhesions increased the contact force by a mean of 36 N. Combined suprapatellar and anterior interval adhesions increased the mean patellofemoral contact force by 120 N. Suprapatellar adhesions resulted in a proximally translated patella from 0 to 60°, and anterior interval adhesions resulted in a distally translated patella at all flexion angles other than 15° (p < 0.05). CONCLUSIONS: The most important finding in this study was that patellofemoral contact forces were significantly increased by simulated adhesions in the suprapatellar pouch and anterior interval. Anterior knee pain and osteoarthritis may result from an increase in patellofemoral contact force due to patellar and quadriceps tendon adhesions. For these patients, arthroscopic lysis of adhesions may be beneficial.

A Transosseous Bone Bridge Repair for Posterior Horn Meniscal Root Tears During Anterior Cruciate Ligament Reconstruction.

Meniscal root tears occur in isolation or concurrently with ligamentous knee injury and cause significantly altered knee mechanics with the loss of normal meniscus hoop stress. This loss of normal meniscus function can result in abnormal knee kinematics and, subsequently, more rapid degenerative changes of the knee articular surface. In the setting of anterior cruciate ligament tear, the posterolateral meniscus root is most commonly damaged. Several techniques exist for meniscus root repair; however, none have been shown to be clearly superior. We present a safe, effective, and reproducible arthroscopic transtibial technique for posterior horn lateral meniscal root tears.

Editorial Commentary: Should the Virchow Triad Have Been a Quartet? Is High Altitude a Risk Factor for Deep Venous Thrombosis After Knee Arthroscopy?

The Virchow triad includes stasis of blood flow, endothelial injury, and hypercoagulability. It forms the physiological foundation for the development of one of our most dreaded complications: deep venous thrombosis. Although the complication rate after knee arthroscopy remains low, significant morbidity may be associated with thromboembolic events. Tyson et al. report an increased incidence of venous thromboembolism in knee operations performed at higher altitudes versus those conducted closer to sea level. Multiple acquired conditions and inherited traits have been identified as risk factors for the development of venous thromboembolism. Geographic altitude should be included within this list.