Background: The pathogenesis of superior labral anterior posterior lesions remains controversial.
Hypothesis: The biceps anchor is more vulnerable to loading with a posterior vector as opposed to an ...in-line pull.
Study Design: Controlled laboratory study.
Methods: Eight pairs of cadaveric shoulders were dissected, and the biceps tendon was loaded to failure in 1 of 2 loading patterns.
Loading pattern A was meant to simulate the eccentric load of the biceps in the deceleration phase of throwing; loading pattern
B was meant to simulate the posterior biceps load of the late cocking phase.
Results: The biceps anchor demonstrated significantly increased ultimate strength with in-line loading (group A, 508 N) as opposed
to posterior loading (group B, 262 N, P <.001). All group B specimens failed at the biceps anchor, resulting in a type II superior labral anterior posterior lesion.
Specimens in group A did not create a superior labral anterior posterior lesion.
Conclusions: Direction of biceps loading resulted in significant differences in the ultimate strength of the biceps anchor and the generation
of superior labral anterior posterior lesions. The biceps anchor was significantly weaker when loaded with a posterior vector.
Relevance: The superior labrum may be most vulnerable to injury in late cocking. The reproducible generation of type II superior labral
anterior posteriorlesions may have applications as a biomechanical model.
Keywords:
superior labral anterior posterior (SLAP) lesion
biceps
labrum
instability
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Zusammenfassung
Hintergrund
Der Bizeps-Labrum-Komplex ist aufgrund der anatomischen Gegebenheiten und der hohen Belastung anfällig für akute Läsionen und degenerative Veränderungen. Eine ...pathologische Veränderung dieser Strukturen stellt einen üblichen Schmerzgenerator am Schultergelenk dar und kann die Funktion signifikant reduzieren. Anatomisch kann der Bizeps-Labrum-Komplex in 3 Zonen eingeteilt werden: Ursprungsbereich, intraartikulärer Verlauf und Bereich im Bizepssehnentunnel.
Diagnostik
Trotz der fokussierten körperlichen Untersuchung und des Fortschritts der bildgebenden Verfahren verbleibt die exakte Lokalisierung der Pathologie eine Herausforderung. Durch eine Arthroskopie lassen sich v. a. Pathologien im Bereich des Ursprungs und im intraartikulären Verlauf gut diagnostizieren, jedoch nur partiell extraartikuläre Pathologien im Bereich des Bizepssehnentunnels.
Therapie
Bei Versagen der konservativen Therapie kann bei korrekter Indikationsstellung operativ eine hohe Patientenzufriedenheit erreicht werden. Während beim jungen aktiven Patienten rekonstruktive Verfahren und die Tenodese der langen Bizepssehne im Vordergrund stehen, lassen sich aber auch durch die Tenotomie hochgradig zufriedenstellende Ergebnisse erreichen. Nichtadressierte pathologische Veränderungen im Bereich des Bizepssehnentunnels können zu einer Schmerzpersistenz führen. In der klinischen Anwendung zur Durchführung der Tenodese zeigen sich sowohl die unterschiedlichen Techniken als auch die verwendeten Implantate als gleichwertig.
Zusammenfassung
Dieser Beitrag beschreibt die anatomischen Grundlagen, pathologische Veränderungen, die fokussierte klinisch-apparative Diagnostik und diskutiert die unterschiedlichen Behandlungsphilosophien und deren Ergebnisse anhand aktueller Literatur.
Purpose: This prospective study aimed to document the pain and functional outcomes, over time, of patients whose SLAP lesions had been repaired with biodegradable tacks.
Methods: Superior labral ...tears were identified in 24 patients from a cohort of 500 patients who had shoulder problems sufficiently disabling to warrant arthroscopic evaluation and management. These labral tears were arthroscopically repaired with 1 to 3 biodegradable tacks (mean, 1.6). Before surgery, all patients completed a questionnaire regarding their shoulder pain and function and were given a systematic clinical examination. To observe their postoperative outcomes over time, the same assessments were made at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after surgery.
Results: After labral reattachment, decreases were noted in the patients’ mean shoulder pain scores at rest (64% at 3 months), at night (76% at 3 months), and with activity (73% at 6 months). The most significant reductions in mean scores occurred between 6 and 12 weeks (
P < .001). Patient-perceived weakness, instability, and stiffness scores also improved from week 6. The ranking of the patients’ “overall problem” reduced from an average ranking of “severe” to “mild” by the third preoperative month (
P < .001) and was still at this level by the time of their 2-year follow-up appointment. Activity levels for 22 of 24 patients returned to their preinjury levels by 6 months after surgery.
Conclusions: Arthroscopically delivered biodegradable tacks effectively managed superior labral tears and, on average, resulted in a near-complete improvement of pain and recovery of function by 3 months. These good outcomes did not improve further or deteriorate at the 2-year follow-up appointment.
Level of Evidence: Level IV, therapeutic case series.
SLAP lesions of the shoulder Snyder, S J; Karzel, R P; Del Pizzo, W ...
Arthroscopy,
1990, Volume:
6, Issue:
4
Journal Article
Peer reviewed
A specific pattern of injury to the superior labrum of the shoulder was identified arthroscopically in twenty-seven patients included in a retrospective review of more than 700 shoulder arthroscopies ...performed at our institution. The injury of the superior labrum begins posteriorly and extends anteriorly, stopping before or at the mid-glenoid notch and including the "anchor" of the biceps tendon to the labrum. We have labeled this injury a "SLAP lesion" (Superior Labrum Anterior and Posterior). There were 23 males and four females with an average age of 37.5 years. Time from injury to surgery averaged 29.3 months. The most common mechanism of injury was a compression force to the shoulder, usually as the result of a fall onto an outstretched arm, with the shoulder positioned in abduction and slight forward flexion at the time of the impact. The most common clinical complaints were pain, greater with overhead activity, and a painful "catching" or "popping" in the shoulder. No imaging test accurately defined the superior labral pathology preoperatively. We divided the superior labrum pathology into four distinct types. Treatment was performed arthroscopically based on the type of SLAP lesion noted at the time of surgery. The SLAP lesion, which has not been previously described, can be diagnosed only arthroscopically and may be treated successfully by arthroscopic techniques alone in many patients.
SLAP lesions are often complex injuries with varied defects and tissue involvement that are challenging to diagnose clinically. The literature notes the need for visualization under arthroscopy for ...adequate diagnostic accuracy. The goal of this article is to provide a current best-evidence synthesis with regard to physical examination tests used for the diagnosis of SLAP lesions. A literature search yielded 17 studies that investigated the diagnostic utility of clinical tests for SLAP lesions. These studies investigated 19 clinical tests. A narrative review and a systematic review of methodological quality using the QUADAS methodological quality assessment tool yielded 3 high-quality diagnostic utility studies. Current best evidence indicates that a negative finding for the passive compression test provides the therapist with the greatest evidence-based confidence that a SLAP lesion is absent. A positive finding on the anterior apprehension maneuver, the anterior slide test, the Jobe relocation test, the passive compression test, the Speed test, and the Yergason test or a combination of positive findings on the Jobe relocation test and the active compression test or the Jobe relocation test and the anterior apprehension maneuver provides the therapist with the research-based confidence required to rule in a SLAP lesion. For ruling in a SLAP lesion, the greatest diagnostic value should likely be placed on a positive finding on the passive compression test. Suggestions for future research are provided.
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DOBA, FSPLJ, IJS, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
The Src-like adaptor protein (SLAP) belongs to the subfamily of adapter proteins that negatively regulate cellular signalling initiated by tyrosine kinases. SLAP has a unique, myristylated ...N-terminus, followed by SH3 and SH2 domains with high homology to Src family tyrosine kinases (SFK) and a unique C-terminal tail, which is important for c-Cbl binding. We have previously shown that SLAP negatively regulates platelet-derived growth factor (PDGF)-induced mitogenesis in fibroblasts and we now report that it regulates F-actin assembly for dorsal ruffles formation. c-Cbl mediated SLAP inhibition towards actin remodelling. Moreover, SLAP enhanced PDGF-induced c-Cbl phosphorylation by SFK. In contrast, SLAP mitogenic inhibition was not mediated by c-Cbl, but it rather involved a competitive mechanism with SFK for PDGF-receptor (PDGFR) association and mitogenic signalling. Accordingly, phosphorylation of the Src mitogenic substrates Stat3 and Shc were reduced by SLAP. Thus, we concluded that SLAP regulates PDGFR signalling by two independent mechanisms: a competitive mechanism for PDGF-induced Src mitogenic signalling and a non-competitive mechanism for dorsal ruffles formation mediated by c-Cbl.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Superior Labrum, Anterior, and Posterior Tears Solomon, Daniel J., MD; Tokish, John M., MD,Col(s), USAFMC
Operative techniques in sports medicine,
09/2012, Volume:
20, Issue:
3
Journal Article
Peer reviewed
Superior labrum, anterior and posterior (SLAP) tears are among the most common injuries seen in the adult shoulder. Several normal anatomic variations occur. This necessitates appropriate ...understanding of normal anatomy and pathology, including the classifications schemes for SLAP. Tips and techniques for repair of SLAP tears are also discussed.
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FSPLJ, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper presents the analytical method to evaluate the impact force and engine noise induced by piston slap considering the detailed piston profile. This method is applied to examine the effect of ...the piston profile on piston slap impact force and frequency spectrum related to the engine noise. The tendency of the piston pin offset to abate the piston slap is compared with the measured one to confirm the availability of this method. And it is pointed out that piston movement in the vicinity of the combustion top dead center is governed by the friction moment around the piston pin and the additional piston pin offset moment induced by combustion pressure.
Fiber components of the shoulder superior labrum Arai, Ryuzo; Kobayashi, Masahiko; Toda, Yoshinobu ...
Surgical and radiologic anatomy (English ed.),
01/2012, Volume:
34, Issue:
1
Journal Article
Peer reviewed
Purpose
The purpose of this study was to investigate the anatomy of the superior glenoid labrum focusing on the fiber arrangement of its components.
Methods
Forty-nine embalmed shoulder girdles were ...removed and each posterior capsule was incised. After recording the macroscopic findings 12 superior-half glenoids were histologically examined. In nine serially sectioned glenoids, four were cut parallel to and five were cut vertical to the glenoid surface. The remaining three glenoids were radially sectioned at the clock position for each hour between 10:00 and 14:00.
Results
The superior labrum had a semi-circular fiber component along the outer margin of the glenoid. In addition, a so-called ‘sheet-like structure’ which branched off the rotator interval and contained many elastic fibers, attached to its anterosuperior portion. The fibers of the sheet-like structure mixes with fibers of the semi-circular component and ran posteriorward. The fibers of the long head of the biceps tendon extended posteriorward from its origin along the glenoid edge. These fibers communicated with other labrum fibers and became a major element of the posterior portion.
Conclusion
The superior labrum is not homogenous. The posterior portion mainly consists of the robust fiber component of the long head of the biceps tendon. The anterosuperior portion includes fibers of the sheet-like structure which contains numerous elastic fibers. Tensile stress from the rotator interval might be conveyed to the anterosuperior labrum.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
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