A Cavalcade of Shoulder Controversies: Deadman Angle Revisited… Divergent Anchor Angles and Depths, and Rotator Cuff Vectors Confuse Comparison… and More

Abstract

No great advance has ever been made in science, politics, or religion, without controversy.Lyman BeecherWe cautiously agree with Mr. Beecher. As we have posited previously, “controversy demands debate”1Lubowitz J.H. Provencher M.T. Poehling G.G. Looking forward and back: The value of arthroscopy, shoulder controversies, hip advancements, cartilage cutting edge, and Arthroscopy Techniques.Arthroscopy. 2013; 29: 1897-1899Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar, 2Lubowitz J.H. D’Agostino Jr., R.B. Provencher M.T. Poehling G.G. Shoulder arthroscopy literature remains controversial.Arthroscopy. 2012; 28: 1581-1583Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar, 3Lubowitz J.H. Provencher M.T. Poehling G.G. Single-row versus double-row rotator cuff repair: The controversy continues.Arthroscopy. 2011; 27: 880-882Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar, 4Lubowitz J.H. Poehling G.G. Controversy in Arthroscopy: Bring it on.Arthroscopy. 2010; 26: 573-574Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar, 5Rossi M.J. D'Agostino Jr., R.B. Provencher M.T. Lubowitz J.H. Could the New England Journal of Medicine be biased against arthroscopic knee surgery?.Arthroscopy. 2014; 30: 536-537Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar because these topics are, by their very nature, complex, and progress is always a goal.6Lubowitz J.H. Provencher M.T. Poehling G.G. Two steps forward, one step back.Arthroscopy. 2011; 27: 1453-1455Abstract Full Text Full Text PDF PubMed Scopus (16) Google ScholarA passionate and healthy debate continues this month on the issue of Stephen Burkhart's classically described “Deadman theory of suture anchors”7Burkhart S.S. The deadman theory of suture anchors: Observations along a south Texas fence line.Arthroscopy. 1995; 11: 119-123Abstract Full Text PDF PubMed Scopus (210) Google Scholar, 8Burkhart S.S. Deadman angle alive and well.Arthroscopy. 2014; 30: 1049-1050Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar regarding the “optimum insertion angle” of a rotator cuff fixation anchor9Lubowitz J.H. Provencher M.T. Rossi M.J. Brand J.C. What is the optimum insertion angle of a suture anchor?.Arthroscopy. 2014; 30: 893-894Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar with a contrarian biomechanical study by Green, Donaldson, Dafydd, Evans, and Kulkarni,10Green R.N. Donaldson O. Dafydd M. Evans S.L. Kulkarni R. Biomechanical study: Determining the optimum insertion angle for screw-in suture anchors—Is Deadman's angle correct?.Arthroscopy. 2014; 30: 1535-1539Google Scholar who report, unlike Dr. Burkhart, that anchor pullout strength is highest when the direction of load is applied in a parallel or nearly parallel vector to the anchor. Further, Green et al. show that Burkhart's Deadman angle results in lower load to anchor failure. Green's refutation of the Deadman theory follows that of Clevenger, Beebe, Strauss, and Kubiak, who similarly called into question Burkhart's research earlier this year.11Clevenger T.A. Beebe M.J. Strauss E.J. Kubiak E.N. The effect of insertion angle on the pullout strength of threaded suture anchors: A validation of the deadman theory.Arthroscopy. 2014; 30: 900-905Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar To recap, Clevenger et al. also recommended anchor insertion toward the vector of pull (at an “obtuse angle”) rather than an “acute” Deadman angle of insertion away from the vector of pull, while Dr. Burkhart, in his recent letter to the editor,8Burkhart S.S. Deadman angle alive and well.Arthroscopy. 2014; 30: 1049-1050Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar holds true to the 45° acute insertion angle based on both extensive clinical experience and theoretical geometry, both of which, of course, carry much deserved weight.However, on further review of these studies, the problem rests in the definition of the angle of the anchor relative to the bone versus the angle of the force vector (pull of the rotator cuff) relative to the bone: these should not be confused. Complicating matters, the angle of the force vector may change, depending on whether the anchor eyelet is fully buried or if the eyelet is proud, and depending on the position of the arm.In other words, the geometries investigated in each of the studies are not the same. Burkhart's Deadman anchor analysis considers a 90° orientation of the “Deadman” (the rock representing the anchor) relative to the ground (i.e., relative to a tangent to the earth representing the humeral head) with a 90° force vector (representing the pull of the rotator cuff) emanating from the Texas fence post, as seen in Figure 1, where we also note that the Deadman is deeply buried but the anchor eyelet is proud. Yet although the force (representing the rotator cuff) pulls at a right angle to the post, the wire transmits this force at a 45° angle between the anchor and the fence post. These distinctions may be critically important, depending on the mode of failure analyzed (e.g., pullout v shear). Then, Dr. Burkhart makes an intuitive intellectual leap (think of a tent pole stake), and analyzes an anchor inserted at a 45° angle to a tangent to the humeral head as seen in Figure 2. Note that in Figure 2, the anchor eyelet is fully buried. As can be seen, we are speaking of many angles, and subtle but different anchor eyelet locations, in this sophisticated and complex analysis.Fig 2Burkhart's Figure 7.7Burkhart S.S. The deadman theory of suture anchors: Observations along a south Texas fence line.Arthroscopy. 1995; 11: 119-123Abstract Full Text PDF PubMed Scopus (210) Google Scholar Note that the anchor as modeled has a 45° orientation with respect to the bone, the pull (force vector) of the rotator cuff has a 90° orientation with respect to the bone, and the anchor eyelet is buried.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Clevenger et al. evaluate a 45° anchor orientation relative to a tangent to the humeral head, with a 90° force vector (representing the pull of the rotator cuff), but critically with a proud anchor eyelet, as noted in Dr. Burkhart's letter8Burkhart S.S. Deadman angle alive and well.Arthroscopy. 2014; 30: 1049-1050Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar and as seen in Figure 3. This seems critical because a proud eyelet could effect not only the mode of failure, but could also effect the angle of the force vector (pull of the cuff). Finally, in this issue, Green et al. consider a 45° anchor orientation relative to a tangent to the humeral head and 150° applied load (or 30° relative to the tangent of the humeral head representing the pull of the rotator cuff) as their analogy to Burkhart's geometry. In summary, and as above, subtle differences may confuse the comparisons.Fig 3Clevenger et al. Figure 1.11Clevenger T.A. Beebe M.J. Strauss E.J. Kubiak E.N. The effect of insertion angle on the pullout strength of threaded suture anchors: A validation of the deadman theory.Arthroscopy. 2014; 30: 900-905Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar Note that the “deadman angle” is defined as 45° orientation with respect to the bone, the force vector is 90° orientation with respect to the bone (or 45° orientation with respect to the anchor), and the anchor eyelet is proud.View Large Image Figure ViewerDownload Hi-res image Download (PPT)But, in the estimation of this editorial's first author, perhaps taking both Burkhart's Deadman and the fence post as separate anchors, it appears that Burkhart's work foreshadowed the construct of the subsequently developed, and now popular, double-row rotator cuff fixation technique. Specifically, Burkhart's Deadman theory includes a fence post itself anchored in the ground. Although it might be a stretch to make an analogy to a double-row rotator cuff repair, maybe the fence post is similar to a medial row anchor, and the Deadman acts as a lateral row anchor; could this support the putative biomechanical superiority of double-row repair?12Mascarenhas R. Chalmers P.N. Sayegh E.T. et al.Is double-row rotator cuff repair clinically superior to single-row rotator cuff repair? A systematic review of overlapping meta-analyses.Arthroscopy. 2014; 30: 1156-1165Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar Maybe for Dr. Burkhart, his intuition and clinical experience provided him a proverbial crystal ball, foreshadowing transosseous equivalent, double-row rotator cuff fixation. We may, in fact, be further along than we thought.Returning to the similar findings that contradict the Deadman theory in the two recent biomechanical studies of Green's and Clevenger's groups, where the anchor resistance to pullout is greater when the anchor is parallel to the direction of pull, we also speculate as to the validity of the synthetic model.13Lubowitz J.H. Poehling G.G. Making sense of basic science in knee and shoulder research.Arthroscopy. 2010; 26: 1011-1012Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar Specifically, do Green and Clevenger fully consider the possibility of the role of tangential shear (i.e., force parallel to the surface of the humeral head) versus axial tension (i.e., force perpendicular to the surface) in synthetic bone compared with native bone? Or the position of the anchor eyelet? Or the static nature of the model? Could the disparity of the findings of Green et al. and Clevenger et al., compared with Burkhart's assertions, result in part from the properties of the model tested?Or could Burkhart be in error? To be fair to Green et al. and Clevenger et al., we acknowledge that Dr. Burkhart is held in such high esteem, and his Deadman theory as long established fact, that we need to be careful; we should not disregard the new studies, which we proudly publish after rigorous peer-review. Rather, we attempt to resolve the discrepancies.Finally, as above, let us not forget that, while it may complicate matters further, the angle of the force vector changes when the shoulder abducts. At the end of the day, we may have a long way to go before the debate is resolved, and we applaud all of our researchers for their contribution. Rather than considering any one study as “flawed,” an optimistic analysis is that all are bringing us closer to the elusive, scientific truth, and in the interim, we continue to ponder with patience and pursue with persistence.14Lubowitz J.H. Poehling G.G. Understanding ACL research requires patience and persistence.Arthroscopy. 2010; 26: 869-871Abstract Full Text Full Text PDF PubMed Scopus (7) Google ScholarRotator cuff research is complex.15Lubowitz J.H. Provencher M.T. Poehling G.G. Single- versus double-row arthroscopic rotator cuff repair: The complexity grows.Arthroscopy. 2012; 28: 1189-1192Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar, 16Lubowitz J.H. McIntyre L. Provencher M.T. Poehling G.G. AAOS rotator cuff clinical practice guideline misses the mark.Arthroscopy. 2012; 28: 589-592Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 17Lubowitz J.H. Poehling G.G. Rotator cuff repair: Obviously.Arthroscopy. 2010; 26: 293-294Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar We have more questions than answers and we hope our readers are not entirely confused; in fact, we hope we are not entirely confused. At any rate, perhaps the answers to these questions illustrate the need for a dynamic, human cadaveric model in future laboratory analyses.Let's move on… Continuing to introduce your December issue, the shoulder cavalcade continues.18Lubowitz J.H. Provencher M.T. Poehling G.G. Knee, shoulder, ankle features, level I shoulder evidence, and ultrasonography expert opinion.Arthroscopy. 2014; 30: 151-152Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar, 19Lubowitz J.H. Provencher M.T. Poehling G.G. The current issue: Clinical shoulder, knee, wrist, hip, and cost-effectiveness analysis.Arthroscopy. 2011; 27: 1313-1316Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar, 20Lubowitz J.H. Provencher M.T. Poehling G.G. AFAWCT shoulder CCR R 2G2BT.Arthroscopy. 2011; 27: 449Abstract Full Text Full Text PDF Scopus (5) Google Scholar, 21Lubowitz J.H. Poehling G.G. In defense of case series: Hip SCFE, shoulder instability and arthritis, double-bundle ACL Cyclops lesions, and elbow OCD.Arthroscopy. 2010; 26: 1411-1413Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar, 22Lubowitz J.H. Poehling G.G. Shoulder, hip, knee, and PRP.Arthroscopy. 2010; 26: 141-142Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar, 23Lubowitz J.H. Poehling G.G. Clinical relevance: Eight shoulders and a knee.Arthroscopy. 2009; 25: 571-572Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 24Lubowitz J.H. Poehling G.G. Keeping it short: Evidence-based international systematic reviews, rotator cuff, knee posterolateral corner, and bupivacaine chondrocytotoxicity.Arthroscopy. 2009; 25: 223Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 25Lubowitz J.H. Poehling G.G. Two on the fast track: Arthroscopic rotator cuff repair and subacromial decompression with coracoacromial ligament excision.Arthroscopy. 2009; 25: 2-3Abstract Full Text Full Text PDF PubMed Scopus (8) Google ScholarRegarding the biceps tendon, Taylor, Fabricant, Baret, Newman, Sliva, Shorey, and O'Brien26Taylor S.A. Fabricant P.D. Baret N.J. et al.Midterm clinical outcomes for arthroscopic subdeltoid transfer of the long head of the biceps tendon to the conjoint tendon.Arthroscopy. 2014; 30: 1574-1581Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar show promising midterm outcome results for treatment of biceps tendonitis with arthroscopic subdeltoid transfer of the long head to the conjoint tendon. Of importance, transfer of the biceps long head was safe. Taking another approach, a cadaveric study from Chan, Behrend, Maloney, Voloshin.27Chan C. Behrend C. Maloney M. Voloshin I. Effects of varying locations for biceps tendon tenotomy and superior labral integrity on shoulder stability in a cadaveric concavity-compression model.Arthroscopy. 2014; 30: 1557-1561Scopus (4) Google Scholar evaluated the effect of long head of the biceps tenotomy at varying locations, as well as the effect of superior labral integrity, on shoulder stability. We won't reveal the outcome. However, we do note that while treatment of biceps pathology seems common, the diversity of treatment options suggests that either we haven't determined the best method, or that so long as the pathology is treated, the method does not matter. History suggests that the first of these two possibilities is more likely.Also related to the superior labrum, Moore-Reed, Kibler, Sciascia, and Uhl28Moore-Reed S.D. Kibler W.B. Sciascia A.D. Uhl U. Preliminary development of a clinical prediction rule for treatment of patients with suspected SLAP tears.Arthroscopy. 2014; 30: 1540-1549Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar address the question, when do SLAP lesions require treatment? More specifically, the authors attempt to predict when nonoperative rehabilitation of SLAP tears will fail. The research is well performed and, while clinicians should study the outcomes, we also encourage future researchers to carefully consider the methods. In our estimation, research analysis of “predictive variables” has substantial clinical relevance.29Lubowitz J.H. Poehling G.G. Do basic science articles have clinical relevance?.Arthroscopy. 2008; 24: 249-250Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar So when do SLAP lesions require treatment? The answer may surprise, and can be found in the pages that follow.For those who desire to tiptoe toward the cutting edge, it is generally safer to be supported by a master like Buddy Savoie.1Lubowitz J.H. Provencher M.T. Poehling G.G. Looking forward and back: The value of arthroscopy, shoulder controversies, hip advancements, cartilage cutting edge, and Arthroscopy Techniques.Arthroscopy. 2013; 29: 1897-1899Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar In this issue, Savoie, Porcellini, Campi, Merolla, and Paladini30Porcellini G. Savoie III, F.H. Campi F. Merolla G. Paladini P. Arthroscopically assisted shoulder arthrodesis: Is it an effective technique?.Arthroscopy. 2014; 30: 1550-1556Scopus (12) Google Scholar report on arthroscopically assisted, mini-open glenohumeral arthrodesis, which is clearly less invasive and perhaps easier than the traditional open procedure. Dr. Savoie reminds us how far we have advanced beyond basic diagnostic arthroscopy and subacromial decompression. Arthroscopy often simplifies difficult problems for surgeons and patients.31Lubowitz J.H. Poehling G.G. Shoulder arthroscopy: Evolution of the revolution.Arthroscopy. 2009; 25: 823-824Abstract Full Text Full Text PDF PubMed Scopus (8) Google ScholarOur shoulder bonanza conveniently concludes with two systematic reviews examining shoulder instability, neatly considering bone loss of the glenoid32Sayegh E.T. Mascarenhas R. Chalmers P.N. Cole B.J. Verma N.N. Romeo A.A. Allograft reconstruction for glenoid bone loss in glenohumeral instability: A systematic review.Arthroscopy. 2014; 30: 1642-1649Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar and humeral head,33Longo U.G. Loppini M. Rizzello G. et al.Remplissage, humeral osteochondral grafts, Weber Osteotomy and shoulder arthroplasty for the management of humeral bone defects in shoulder instability: Systematic review and quantitative synthesis of the literature.Arthroscopy. 2014; 30: 1650-1666Scopus (0) Google Scholar respectively. Simply put, allograft works on the glenoid side, while remplissage seems safe and superior for the humerus. These systematic reviews with quantitative synthesis of the literature immensely clarify one controversial shoulder topic. In contrast, the current issue suggests that the ideal angle for rotator cuff suture anchor insertion provokes continuing debate. No great advance has ever been made in science, politics, or religion, without controversy.Lyman Beecher We cautiously agree with Mr. Beecher. As we have posited previously, “controversy demands debate”1Lubowitz J.H. Provencher M.T. Poehling G.G. Looking forward and back: The value of arthroscopy, shoulder controversies, hip advancements, cartilage cutting edge, and Arthroscopy Techniques.Arthroscopy. 2013; 29: 1897-1899Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar, 2Lubowitz J.H. D’Agostino Jr., R.B. Provencher M.T. Poehling G.G. Shoulder arthroscopy literature remains controversial.Arthroscopy. 2012; 28: 1581-1583Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar, 3Lubowitz J.H. Provencher M.T. Poehling G.G. Single-row versus double-row rotator cuff repair: The controversy continues.Arthroscopy. 2011; 27: 880-882Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar, 4Lubowitz J.H. Poehling G.G. Controversy in Arthroscopy: Bring it on.Arthroscopy. 2010; 26: 573-574Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar, 5Rossi M.J. D'Agostino Jr., R.B. Provencher M.T. Lubowitz J.H. Could the New England Journal of Medicine be biased against arthroscopic knee surgery?.Arthroscopy. 2014; 30: 536-537Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar because these topics are, by their very nature, complex, and progress is always a goal.6Lubowitz J.H. Provencher M.T. Poehling G.G. Two steps forward, one step back.Arthroscopy. 2011; 27: 1453-1455Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar A passionate and healthy debate continues this month on the issue of Stephen Burkhart's classically described “Deadman theory of suture anchors”7Burkhart S.S. The deadman theory of suture anchors: Observations along a south Texas fence line.Arthroscopy. 1995; 11: 119-123Abstract Full Text PDF PubMed Scopus (210) Google Scholar, 8Burkhart S.S. Deadman angle alive and well.Arthroscopy. 2014; 30: 1049-1050Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar regarding the “optimum insertion angle” of a rotator cuff fixation anchor9Lubowitz J.H. Provencher M.T. Rossi M.J. Brand J.C. What is the optimum insertion angle of a suture anchor?.Arthroscopy. 2014; 30: 893-894Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar with a contrarian biomechanical study by Green, Donaldson, Dafydd, Evans, and Kulkarni,10Green R.N. Donaldson O. Dafydd M. Evans S.L. Kulkarni R. Biomechanical study: Determining the optimum insertion angle for screw-in suture anchors—Is Deadman's angle correct?.Arthroscopy. 2014; 30: 1535-1539Google Scholar who report, unlike Dr. Burkhart, that anchor pullout strength is highest when the direction of load is applied in a parallel or nearly parallel vector to the anchor. Further, Green et al. show that Burkhart's Deadman angle results in lower load to anchor failure. Green's refutation of the Deadman theory follows that of Clevenger, Beebe, Strauss, and Kubiak, who similarly called into question Burkhart's research earlier this year.11Clevenger T.A. Beebe M.J. Strauss E.J. Kubiak E.N. The effect of insertion angle on the pullout strength of threaded suture anchors: A validation of the deadman theory.Arthroscopy. 2014; 30: 900-905Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar To recap, Clevenger et al. also recommended anchor insertion toward the vector of pull (at an “obtuse angle”) rather than an “acute” Deadman angle of insertion away from the vector of pull, while Dr. Burkhart, in his recent letter to the editor,8Burkhart S.S. Deadman angle alive and well.Arthroscopy. 2014; 30: 1049-1050Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar holds true to the 45° acute insertion angle based on both extensive clinical experience and theoretical geometry, both of which, of course, carry much deserved weight. However, on further review of these studies, the problem rests in the definition of the angle of the anchor relative to the bone versus the angle of the force vector (pull of the rotator cuff) relative to the bone: these should not be confused. Complicating matters, the angle of the force vector may change, depending on whether the anchor eyelet is fully buried or if the eyelet is proud, and depending on the position of the arm. In other words, the geometries investigated in each of the studies are not the same. Burkhart's Deadman anchor analysis considers a 90° orientation of the “Deadman” (the rock representing the anchor) relative to the ground (i.e., relative to a tangent to the earth representing the humeral head) with a 90° force vector (representing the pull of the rotator cuff) emanating from the Texas fence post, as seen in Figure 1, where we also note that the Deadman is deeply buried but the anchor eyelet is proud. Yet although the force (representing the rotator cuff) pulls at a right angle to the post, the wire transmits this force at a 45° angle between the anchor and the fence post. These distinctions may be critically important, depending on the mode of failure analyzed (e.g., pullout v shear). Then, Dr. Burkhart makes an intuitive intellectual leap (think of a tent pole stake), and analyzes an anchor inserted at a 45° angle to a tangent to the humeral head as seen in Figure 2. Note that in Figure 2, the anchor eyelet is fully buried. As can be seen, we are speaking of many angles, and subtle but different anchor eyelet locations, in this sophisticated and complex analysis. Clevenger et al. evaluate a 45° anchor orientation relative to a tangent to the humeral head, with a 90° force vector (representing the pull of the rotator cuff), but critically with a proud anchor eyelet, as noted in Dr. Burkhart's letter8Burkhart S.S. Deadman angle alive and well.Arthroscopy. 2014; 30: 1049-1050Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar and as seen in Figure 3. This seems critical because a proud eyelet could effect not only the mode of failure, but could also effect the angle of the force vector (pull of the cuff). Finally, in this issue, Green et al. consider a 45° anchor orientation relative to a tangent to the humeral head and 150° applied load (or 30° relative to the tangent of the humeral head representing the pull of the rotator cuff) as their analogy to Burkhart's geometry. In summary, and as above, subtle differences may confuse the comparisons. But, in the estimation of this editorial's first author, perhaps taking both Burkhart's Deadman and the fence post as separate anchors, it appears that Burkhart's work foreshadowed the construct of the subsequently developed, and now popular, double-row rotator cuff fixation technique. Specifically, Burkhart's Deadman theory includes a fence post itself anchored in the ground. Although it might be a stretch to make an analogy to a double-row rotator cuff repair, maybe the fence post is similar to a medial row anchor, and the Deadman acts as a lateral row anchor; could this support the putative biomechanical superiority of double-row repair?12Mascarenhas R. Chalmers P.N. Sayegh E.T. et al.Is double-row rotator cuff repair clinically superior to single-row rotator cuff repair? A systematic review of overlapping meta-analyses.Arthroscopy. 2014; 30: 1156-1165Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar Maybe for Dr. Burkhart, his intuition and clinical experience provided him a proverbial crystal ball, foreshadowing transosseous equivalent, double-row rotator cuff fixation. We may, in fact, be further along than we thought. Returning to the similar findings that contradict the Deadman theory in the two recent biomechanical studies of Green's and Clevenger's groups, where the anchor resistance to pullout is greater when the anchor is parallel to the direction of pull, we also speculate as to the validity of the synthetic model.13Lubowitz J.H. Poehling G.G. Making sense of basic science in knee and shoulder research.Arthroscopy. 2010; 26: 1011-1012Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar Specifically, do Green and Clevenger fully consider the possibility of the role of tangential shear (i.e., force parallel to the surface of the humeral head) versus axial tension (i.e., force perpendicular to the surface) in synthetic bone compared with native bone? Or the position of the anchor eyelet? Or the static nature of the model? Could the disparity of the findings of Green et al. and Clevenger et al., compared with Burkhart's assertions, result in part from the properties of the model tested? Or could Burkhart be in error? To be fair to Green et al. and Clevenger et al., we acknowledge that Dr. Burkhart is held in such high esteem, and his Deadman theory as long established fact, that we need to be careful; we should not disregard the new studies, which we proudly publish after rigorous peer-review. Rather, we attempt to resolve the discrepancies. Finally, as above, let us not forget that, while it may complicate matters further, the angle of the force vector changes when the shoulder abducts. At the end of the day, we may have a long way to go before the debate is resolved, and we applaud all of our researchers for their contribution. Rather than considering any one study as “flawed,” an optimistic analysis is that all are bringing us closer to the elusive, scientific truth, and in the interim, we continue to ponder with patience and pursue with persistence.14Lubowitz J.H. Poehling G.G. Understanding ACL research requires patience and persistence.Arthroscopy. 2010; 26: 869-871Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar Rotator cuff research is complex.15Lubowitz J.H. Provencher M.T. Poehling G.G. Single- versus double-row arthroscopic rotator cuff repair: The complexity grows.Arthroscopy. 2012; 28: 1189-1192Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar, 16Lubowitz J.H. McIntyre L. Provencher M.T. Poehling G.G. AAOS rotator cuff clinical practice guideline misses the mark.Arthroscopy. 2012; 28: 589-592Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 17Lubowitz J.H. Poehling G.G. Rotator cuff repair: Obviously.Arthroscopy. 2010; 26: 293-294Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar We have more questions than answers and we hope our readers are not entirely confused; in fact, we hope we are not entirely confused. At any rate, perhaps the answers to these questions illustrate the need for a dynamic, human cadaveric model in future laboratory analyses. Let's move on… Continuing to introduce your December issue, the shoulder cavalcade continues.18Lubowitz J.H. Provencher M.T. Poehling G.G. Knee, shoulder, ankle features, level I shoulder evidence, and ultrasonography expert opinion.Arthroscopy. 2014; 30: 151-152Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar, 19Lubowitz J.H. Provencher M.T. Poehling G.G. The current issue: Clinical shoulder, knee, wrist, hip, and cost-effectiveness analysis.Arthroscopy. 2011; 27: 1313-1316Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar, 20Lubowitz J.H. Provencher M.T. Poehling G.G. AFAWCT shoulder CCR R 2G2BT.Arthroscopy. 2011; 27: 449Abstract Full Text Full Text PDF Scopus (5) Google Scholar, 21Lubowitz J.H. Poehling G.G. In defense of case series: Hip SCFE, shoulder instability and arthritis, double-bundle ACL Cyclops lesions, and elbow OCD.Arthroscopy. 2010; 26: 1411-1413Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar, 22Lubowitz J.H. Poehling G.G. Shoulder, hip, knee, and PRP.Arthroscopy. 2010; 26: 141-142Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar, 23Lubowitz J.H. Poehling G.G. Clinical relevance: Eight shoulders and a knee.Arthroscopy. 2009; 25: 571-572Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 24Lubowitz J.H. Poehling G.G. Keeping it short: Evidence-based international systematic reviews, rotator cuff, knee posterolateral corner, and bupivacaine chondrocytotoxicity.Arthroscopy. 2009; 25: 223Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 25Lubowitz J.H. Poehling G.G. Two on the fast track: Arthroscopic rotator cuff repair and subacromial decompression with coracoacromial ligament excision.Arthroscopy. 2009; 25: 2-3Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar Regarding the biceps tendon, Taylor, Fabricant, Baret, Newman, Sliva, Shorey, and O'Brien26Taylor S.A. Fabricant P.D. Baret N.J. et al.Midterm clinical outcomes for arthroscopic subdeltoid transfer of the long head of the biceps tendon to the conjoint tendon.Arthroscopy. 2014; 30: 1574-1581Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar show promising midterm outcome results for treatment of biceps tendonitis with arthroscopic subdeltoid transfer of the long head to the conjoint tendon. Of importance, transfer of the biceps long head was safe. Taking another approach, a cadaveric study from Chan, Behrend, Maloney, Voloshin.27Chan C. Behrend C. Maloney M. Voloshin I. Effects of varying locations for biceps tendon tenotomy and superior labral integrity on shoulder stability in a cadaveric concavity-compression model.Arthroscopy. 2014; 30: 1557-1561Scopus (4) Google Scholar evaluated the effect of long head of the biceps tenotomy at varying locations, as well as the effect of superior labral integrity, on shoulder stability. We won't reveal the outcome. However, we do note that while treatment of biceps pathology seems common, the diversity of treatment options suggests that either we haven't determined the best method, or that so long as the pathology is treated, the method does not matter. History suggests that the first of these two possibilities is more likely. Also related to the superior labrum, Moore-Reed, Kibler, Sciascia, and Uhl28Moore-Reed S.D. Kibler W.B. Sciascia A.D. Uhl U. Preliminary development of a clinical prediction rule for treatment of patients with suspected SLAP tears.Arthroscopy. 2014; 30: 1540-1549Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar address the question, when do SLAP lesions require treatment? More specifically, the authors attempt to predict when nonoperative rehabilitation of SLAP tears will fail. The research is well performed and, while clinicians should study the outcomes, we also encourage future researchers to carefully consider the methods. In our estimation, research analysis of “predictive variables” has substantial clinical relevance.29Lubowitz J.H. Poehling G.G. Do basic science articles have clinical relevance?.Arthroscopy. 2008; 24: 249-250Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar So when do SLAP lesions require treatment? The answer may surprise, and can be found in the pages that follow. For those who desire to tiptoe toward the cutting edge, it is generally safer to be supported by a master like Buddy Savoie.1Lubowitz J.H. Provencher M.T. Poehling G.G. Looking forward and back: The value of arthroscopy, shoulder controversies, hip advancements, cartilage cutting edge, and Arthroscopy Techniques.Arthroscopy. 2013; 29: 1897-1899Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar In this issue, Savoie, Porcellini, Campi, Merolla, and Paladini30Porcellini G. Savoie III, F.H. Campi F. Merolla G. Paladini P. Arthroscopically assisted shoulder arthrodesis: Is it an effective technique?.Arthroscopy. 2014; 30: 1550-1556Scopus (12) Google Scholar report on arthroscopically assisted, mini-open glenohumeral arthrodesis, which is clearly less invasive and perhaps easier than the traditional open procedure. Dr. Savoie reminds us how far we have advanced beyond basic diagnostic arthroscopy and subacromial decompression. Arthroscopy often simplifies difficult problems for surgeons and patients.31Lubowitz J.H. Poehling G.G. Shoulder arthroscopy: Evolution of the revolution.Arthroscopy. 2009; 25: 823-824Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar Our shoulder bonanza conveniently concludes with two systematic reviews examining shoulder instability, neatly considering bone loss of the glenoid32Sayegh E.T. Mascarenhas R. Chalmers P.N. Cole B.J. Verma N.N. Romeo A.A. Allograft reconstruction for glenoid bone loss in glenohumeral instability: A systematic review.Arthroscopy. 2014; 30: 1642-1649Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar and humeral head,33Longo U.G. Loppini M. Rizzello G. et al.Remplissage, humeral osteochondral grafts, Weber Osteotomy and shoulder arthroplasty for the management of humeral bone defects in shoulder instability: Systematic review and quantitative synthesis of the literature.Arthroscopy. 2014; 30: 1650-1666Scopus (0) Google Scholar respectively. Simply put, allograft works on the glenoid side, while remplissage seems safe and superior for the humerus. These systematic reviews with quantitative synthesis of the literature immensely clarify one controversial shoulder topic. In contrast, the current issue suggests that the ideal angle for rotator cuff suture anchor insertion provokes continuing debate.