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113


The rising incidence of arthroscopic superior labrum anterior and posterior (SLAP) repairs

Onyekwelu, Ikemefuna; Khatib, Omar; Zuckerman, Joseph D; Rokito, Andrew S; Kwon, Young W
BACKGROUND: Superior labrum anterior-posterior (SLAP) lesions of the shoulder that require surgical repair are relatively uncommon. However, recent observations suggest that there may be a rise in the incidence of SLAP lesion repair. MATERIALS AND METHODS: The Statewide Planning and Research Cooperative Systems (SPARCS) database from the New York State Department of Health was used to acquire data for all outpatient ambulatory surgery procedures that were performed in New York State from 2002 to 2010. The data were reviewed and analyzed to compare the incidence of arthroscopic SLAP lesion repairs relative to other outpatient surgical procedures. RESULTS: Within New York State, from 2002 to 2010, the number of all ambulatory surgical procedures increased 55%, from 1,411,633 to 2,189,991. Correspondingly, the number of ambulatory orthopedic procedures increased 135%, from 118,126 to 278,136. In comparison, the number of arthroscopic SLAP repairs increased 464%, from 765 to 4,313 (P < .0001). This represented a population-based incidence of 4.0/100,000 in 2002 and 22.3/100,000 in 2010. The mean age of patients undergoing arthroscopic SLAP repair in 2002 was 37 +/- 14 years. The mean age in 2010 was 40 +/- 14 years (P < .0001). CONCLUSIONS: The data suggest a substantial increase in the number of arthroscopic SLAP repairs that is significantly more rapid than the rising rate of outpatient orthopedic surgical procedures. In addition, there is a significant increase in the age of patients who are being treated with arthroscopic SLAP repairs.
PMID: 22608836
ISSN: 1058-2746
CID: 167507

Return to sports after shoulder arthroplasty: a survey of surgeons' preferences

Golant, Alexander; Christoforou, Dimitrios; Zuckerman, Joseph D; Kwon, Young W
BACKGROUND: Shoulder arthroplasty has become more prevalent, and patients undergoing shoulder arthroplasty are becoming more active. Recommendations for return to athletic activity have not recently been updated and do not consider the newest arthroplasty options. METHODS: A survey was distributed to 310 members of the American Shoulder and Elbow Surgeons, inquiring about allowed participation in 28 different athletic activities after 5 types of shoulder arthroplasty options (total shoulder arthroplasty, hemiarthroplasty, humeral resurfacing, total shoulder resurfacing, and reverse shoulder arthroplasty). RESULTS: The response rate to the survey was 30.3%, with 74.1% of respondents allowing some return to athletic activity after shoulder arthroplasty. The 28 athletic activities were grouped into 4 categories based on the load and possible impact to the shoulder. Only 51% of respondents allowed any participation in contact sports, whereas 90% allowed some participation in noncontact low-load sports. Return to sports after humeral resurfacing was highest, at 92.0% of the respondents, whereas the least percentage of surgeons allowed sports after reverse total shoulder arthroplasty, at 45.2%. CONCLUSION: The majority of surveyed surgeons allowed some return to sports after shoulder arthroplasty. Surgeons were more likely to recommend return to sports if the activities did not involve significant contact, risk of fall or collision, or application of high loads to the shoulder joint. Surgeons were also more likely to recommend return to sports if the arthroplasty did not involve the glenoid. CLINICAL RELEVANCE: The results of this survey may help surgeons counsel patients regarding return to specific athletic activities after various types of shoulder arthroplasty.
PMID: 21393018
ISSN: 1058-2746
CID: 162019

Evolution of the reverse total shoulder prosthesis

Jazayeri, Reza; Kwon, Young W
Over the last decade, reverse total shoulder arthroplasty has gained significant popularity due to its ability to address difficult reconstructive shoulder problems that could not be adequately treated in the past. The concept of the reverse shoulder prosthesis was introduced in the 1970s, but the initial attempts were associated with high complication and implant failure rates. The pioneering work of Paul Grammont (shifting the center of rotation medially and distally) and the development of the DELTA prosthesis have been fundamental to all subsequent reverse shoulder arthroplasty systems. These semiconstrained prostheses utilize the deltoid to improve function and stability of the shoulder joint by coupling a convex glenoid with a concave humeral component. Modern generations of reverse shoulder prosthesis continue to evolve on the fundamentals of Grammont. Though results of these new prosthesis demonstrate promising outcomes, many controversies and challenges continue to be refined. An historical review of the evolution of reverse shoulder arthroplasty is presented, as well as the currently expanding indications for its application
PMID: 21332439
ISSN: 1936-9727
CID: 133194

Management of humeral and glenoid bone loss--associated with glenohumeral instability

DiPaola, Matthew J; Jazrawi, Laith M; Rokito, Andrew S; Kwon, Young W; Patel, Lava; Pahk, Brian; Zuckerman, Joseph D
Anterior glenohumeral instability complicated by bone loss is a challenging problem and, when severe, may require surgical treatment with bone grafting. We review our institution's experience with humeral head and glenoid bone grafting for large Hill-Sachs lesions and glenoid defects. MATERIALS AND METHODS: Patients who underwent intra-articular bone reconstruction for Hill-Sachs and large glenoid defects for anterior instability at our institution during 2002-2008 were retrospectively reviewed. Those who had undergone concomitant humeral head replacement were excluded. Six patients were identified as having undergone allograft or autograft iliac crest bone graft reconstruction of the glenoid, with four available for full follow-up (average 39 months; range, 7 to 63). Five patients were identified as having undergone humeral head allograft reconstruction and four were available for full follow-up (average 28 months; range, 11 to 40). The remaining three patients were available for telephone follow-up. American Shoulder and Elbow Society (ASES) and University of California, Los Angles (UCLA) scores were recorded and radiographs obtained. RESULTS: Average postoperative ASES and UCLA scores for glenoid bone graft patients were 91 and 33, respectively. Average postoperative ASES and UCLA scores for humeral bone graft patients were 85.3 and 28.4, respectively. Glenoid bone graft shoulders, when compared to the opposite normal side, lost an average of 3 degrees of forward flexion, 10 degrees of external rotation, and two levels of internal rotation. Humeral head bone-grafted shoulders, lost an average of 23 degrees of forward flexion, 8 degrees of external rotation, and two levels of internal rotation. No episodes of recurrent subluxation or dislocations were reported. Radiographs showed no evidence of graft resorption or hardware prominence. CONCLUSIONS: Bone grafting procedures around the shoulder for the treatment of instability provided relief from recurrent instability and good functional results
PMID: 21162700
ISSN: 1936-9727
CID: 133848

Suture anchor loading after rotator cuff repair: Effects of an additional lateral row

Kulwicki, Kevin J; Kwon, Young W; Kummer, Frederick J
HYPOTHESIS: Our initial hypothesis was that the medial row of double-row rotator cuff repair techniques would bear most of the load on the repaired cuff. MATERIALS AND METHODS: Six cadaver shoulders underwent simulated rotator cuff repairs using sequential single row, double-row, and suture-bridge repair techniques. Suture tensions at each anchor were measured for several static, simulated shoulder positions by specially designed, instrumented anchors. RESULTS: Significantly greater suture tensions were measured in the anchors in a single row repair construct than either the double row repair or suture bridge repair construct (P < .001). In the double-row and suture bridge techniques, there was no apparent difference in the loads born by the medial and lateral row anchors. Shoulder abduction from 45 degrees to 60 degrees had little effect on anchor tensions; 45 degrees internal and external rotation significantly (P = .032) increased loads on the anterior and posterior anchors by at least 125%. DISCUSSION: Forces are transmitted through the entire portion of the tendon at its humeral fixation, loading the lateral anchors as well as the medial row for the techniques studied. This 'load sharing' can explain the higher fixation strengths of double row techniques seen experimentally. CONCLUSION: The magnitude and distribution of anchor suture tensions could have important implications for lateral row fixation devices and post-operative positioning and activity. LEVEL OF EVIDENCE: Basic Science
PMID: 19560944
ISSN: 1532-6500
CID: 105921

The rotator interval: a review of anatomy, function, and normal and abnormal MRI appearance

Petchprapa, Catherine N; Beltran, Luis S; Jazrawi, Laith M; Kwon, Young W; Babb, James S; Recht, Michael P
OBJECTIVE: The purpose of this article is to review imaging of the rotator interval, an anatomically complex region in the shoulder that plays an important role in the normal function of the shoulder joint. The rotator interval can be difficult to evaluate by imaging, and it is not routinely evaluated arthroscopically unless the clinical examination or imaging findings suggest an abnormality of the rotator interval. Rotator interval pathology is implicated in glenohumeral instability, biceps instability and adhesive capsulitis-entities which remain a challenge to diagnose and treat. CONCLUSION: Imaging can play an important role in increasing suspicion for injury to the rotator interval so that this region can be evaluated and appropriate treatment can be initiated
PMID: 20729432
ISSN: 1546-3141
CID: 111895

Revision shoulder arthroplasty: an analysis of indications and outcomes

Sajadi, Kaveh R; Kwon, Young W; Zuckerman, Joseph D
BACKGROUND: We reviewed all revision operations performed by a single surgeon on previous hemi- and total shoulder arthroplasties from November 1987 to March 2005. METHOD: Thirty-five patients' charts were reviewed to determine the causes of failures. In addition, their outcomes after the revision surgery were analyzed. RESULTS: Overall, results were satisfactory in 71% by Neer criteria at a mean follow-up of 27.6 months. Outcomes were related to reason for failure. When failure was because of glenoid erosion, loosening, or humeral loosening, the mean improvement in forward elevation (FE) (28.9 degrees ) and external rotation (ER) (16.1 degrees ) was significantly better (P=.024 FE; P=.000 ER) than when the failure was because of infection, soft-tissue problems, or pain of undetermined origin (FE=-5.6 degrees ; ER=-6.8 degrees ).Likewise, UCLA scores in the first group were significantly better than in the second group (P=.003). In the first group, 16/18 patients were satisfied, while in the second group only 4/17 were satisfied. CONCLUSION: Our data suggest that patients whose revisions are because of glenoid erosion or component loosening can expect to have better outcomes than those whose revisions are performed for infection, instability, or other soft-tissue problems
PMID: 19733095
ISSN: 1532-6500
CID: 115367

Analysis of reverse total shoulder joint forces and glenoid fixation

Kwon, Young W; Forman, Rachel E; Walker, Peter S; Zuckerman, Joseph D
Reverse total shoulder arthroplasty (rTSA) implants are intended to restore stability and function to shoulders with rotator cuff deficiency. The implant consists of a glenosphere projecting from a glenoid baseplate and articulating in a socket at the proximal end of a humeral component. Despite the demonstrated clinical efficacy, little information is available regarding the joint forces about this construct and the stability of the glenoid component against these forces. Our hypotheses were that the joint forces about the rTSA were comparable to that about a normal shoulder joint, and that the micromotion between the baseplate and the scapula against these loads would be sufficiently low to induce bone ingrowth. To investigate this, a custom testing rig was constructed to simulate active shoulder elevation in fresh-frozen shoulder specimens. The forces about the rTSA were calculated and found to include compressive and shear forces up to 0.7 and 0.4 BW, respectively. In contrast to a normal shoulder, where the joint forces peak at 90 degrees of abduction, forces about the rTSA were highest at about 60 degrees of abduction. These forces were then applied in cyclic loading conditions to the glenoid baseplate, and the micromotion of the implant relative to the bone was measured in the four quadrants of the component. For two different rTSA designs (DePuy Delta III(R) and Encore RSP(R)) and in the entire range of the fixation testing, the cyclical micromotions were always less than 62 microm. Thus, under loading conditions similar to physiological shoulder elevation, micromotion of the glenoid component was sufficiently low and within previously published limits to induce bone ingrowth
PMID: 21162705
ISSN: 1936-9727
CID: 117344

A novel method to determine suture anchor loading after rotator cuff repair--a study of two double-row techniques

Khoury, Lisa D; Kwon, Young W; Kummer, Frederick J
BACKGROUND: The addition of a lateral suture anchor fixation row to rotator cuff repairs has been shown to improve initial cuff reattachment strength and footprint area. This study evaluated the mechanical function of this lateral row by measuring suture tensions at the individual anchor sites. MATERIALS AND METHODS: Eight cadaveric shoulders underwent simulated rotator cuff repairs, using either double row or suture-bridge repair techniques. Suture tensions at each anchor were measured for several static, simulated shoulder positions relevant to postoperative patient management by specially designed instrumented anchors. RESULTS: Significantly greater suture tensions were measured at the medial anchor sites than at the lateral sites for the double-row (p < 0.001), as well as the suture-bridge constructs (p < 0.016). In the double-row technique, the lateral row sustained 21% (range, 6 to 31) of the total anchor load; whereas, in the suture-bridge technique, the lateral row sustained 33% (range, 8 to 42). Shoulder abduction from 45 degrees to 60 degrees had little effect on anchor tensions; 20 degrees internal and external rotation significantly (p = 0.032) increased loads on the anterior and posterior anchors. CONCLUSIONS: Forces are transmitted through the entire body of the tendon at its humeral fixation, loading the lateral anchors, as well as the medial row, for the two fixation techniques studied. These findings explain the higher laboratory-obtained fixation strengths of double-row techniques. The magnitude and distribution of anchor suture tensions could have important implications for postoperative positioning and activity
PMID: 20345359
ISSN: 1936-9727
CID: 120731

Complications of Arthroscopic Shoulder Surgery: Miscellaneous Shoulder Conditions

Chapter by: Golant, Alexander; Kwon, Young W.
in: Complications In Knee And Soulder Surgery by Meislin, RJ; Halbrecht, J [Eds]
pp. 265-272
ISBN: 978-1-84882-202-3
CID: 5297932