Try a new search

Format these results:

Searched for:

in-biosketch:true

person:kwony02

Total Results:

113


Partial subscapularis release for total shoulder arthroplasty: a biomechanical comparison of two techniques

Kummer, Frederick J; Mahoney, Andrew P; Onyekwelu, Ikemefuna; Kwon, Young W
BACKGROUND:Glenohumeral joint exposure during total shoulder arthroplasty (TSA) is obtained by releasing the subscapularis (SSC) with either an osteotomy or a tenotomy. Recently, concerns regarding SSC dysfunction after TSA have been raised. In order to avoid this complication, alternative surgical approaches that release the inferior 50% or 10% of the tendon have been described. While a 10% release of the SSC would theoretically lower the likelihood of postoperative SSC dysfunction, releasing 50% would provide greater surgical exposure but possibly have a weaker SS attachment. Therefore, we sought to compare the SSC attachment strengths of these two techniques. MATERIALS AND METHODS/METHODS:Each of eight matched pairs of cadaveric shoulders were tested. The inferior 10% of the SSC tendon was released on one side. On the contralateral side, the inferior 50% of the SSC was released and then repaired with a 5.5 mm suture anchor. The specimens were then mechanically tested to failure. RESULTS:The load to failure for the 10% release specimens was 682 ± 153 N and 493 ± 212 N for the 50% release specimens (p = 0.036). Failures in both groups occurred mainly at the musculotendonous junction. DISCUSSION/CONCLUSIONS:The SSC humeral attachment strength after releasing the inferior 10% was 30% greater than the 50% re- lease with repair. Thus, although releasing the inferior 50% of the SSC tendon may provide greater surgical exposure, maintaining the SSC with minimal release may be preferable in decreasing the rate of post TSA SSC dysfunction.
PMID: 25986348
ISSN: 2328-5273
CID: 3568412

Radiocapitellar Joint Contact Pressures Following Radial Head Arthroplasty

Cohn, Michael; Glait, Sergio A; Sapienza, Anthony; Kwon, Young W
PURPOSE: To determine the radial head arthroplasty length that best replicates the native radiocapitellar contact pressure. METHODS: Eight cadaveric elbows (4 matched pairs) with an average age of 73 years were tested. All specimens were ligamentously stable and without visible cartilage wear. Radiocapitellar contact pressures were digitally analyzed during simulated joint loading at 0 degrees , 45 degrees , and 90 degrees of elbow flexion and neutral rotation in the intact specimens and after ligament-preserving radial head arthroplasty at -2 mm, 0 mm, and +2 mm of the native length. The results were analyzed using 1-way analysis of variance and post hoc Tukey pairwise comparison tests. RESULTS: Paired analysis demonstrated significantly decreased mean contact pressures when comparing the native versus the minus 2 groups. Significantly decreased maximum contact pressures were also noted between the native and the minus 2 groups. Examining the mean contact pressures showed no significant difference between the native and the zero group and the native and the plus 2 groups. As for the maximum contact pressures, there was also no significant difference between the native and the zero group and the native and the plus 2 group. CONCLUSIONS: Up to 2 mm of overlengthening may be tolerated under simulated loading conditions without significantly increasing contact pressures of the radiocapitellar joint. Surgeons can use this knowledge along with radiographic parameters and intraoperative examination of elbow stability to gauge the appropriate size of the radial head implant to be used in order to decrease the risk of overstuffing the joint and minimizing radiocapitellar chondral wear. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.
PMID: 24997784
ISSN: 0363-5023
CID: 1066172

Suprascapular and axillary nerve injuries

Chapter by: Strauss, EJ; Alaia, MJ; Kwon, YW
in: Disorders of the Shoulder: Reconstruction by
pp. 661-680
ISBN: 9781469837826
CID: 2170782

Complications of proximal humerus fractures: Evaluation and management

Chapter by: Kwon, YW; Schubkegel, TA
in: Disorders of the Shoulder: Diagnosis and Management: Shoulder Trauma by
pp. 73-95
ISBN: 9781469837864
CID: 2170882

The rise of the metal elbow

Fajardo, Marc; Kwon, Young W
Painful arthritis of the elbow joint has long been a challenging problem. Elbow arthroplasty has emerged as viable treatment method for many patients. Implant design and surgical technique have evolved to provide more predict-able symptom relief without compromising function. Elbow arthroplasty can now be used to treat a wide variety of conditions, including osteoarthritis, rheumatoid arthritis, and fractures. This review article presents historical and contemporary perspectives on elbow arthroplasty. A thorough discussion of implant design, surgical technique, and clinical outcomes is presented.
PMID: 24032580
ISSN: 2328-4633
CID: 845722

The rising incidence of rotator cuff repairs

Ensor, Kelsey L; Kwon, Young W; Dibeneditto, Michael R; Zuckerman, Joseph D; Rokito, Andrew S
BACKGROUND: Rotator cuff repairs (RCRs) have become increasingly common. Several studies have shown variation in the indications for this procedure. We chose to track the incidence of RCRs in New York State (NYS) from 1995 to 2009. We hypothesized that after the introduction of the Current Procedural Terminology (CPT) code 29827 for arthroscopic RCR, there would be a significant increase in the rate of RCRs performed in NYS. MATERIALS AND METHODS: The NYS Department of Health's Statewide Planning and Research Cooperative System (SPARCS) database was queried for reported RCRs between the years 1995 and 2009. Using the International Classification of Diseases, Ninth Revision, Clinical Modification procedural code 83.63 and CPT codes 23410, 23412, 23420, and 29827, we collected and analyzed data on RCR procedures. RESULTS: A total of 168,780 RCRs were performed in NYS from 1995 to 2009. In 1995, the population incidence of RCRs was 23.5 per 100,000. In comparison, in 2009, the population incidence was 83.1 per 100,000, an increase of 238% (P < .0001). The percentage of individuals aged between 45 and 65 years undergoing RCR increased from 53.0% to 64.2% during this same period. CONCLUSIONS: There has been a notable increase in the volume of RCRs performed in NYS. In addition, after the introduction of CPT code 29827 in 2003, the increase in the incidence of RCRs became significantly more pronounced.
PMID: 23466172
ISSN: 1058-2746
CID: 590302

Sodium hyaluronate for the treatment of chronic shoulder pain associated with glenohumeral osteoarthritis: a multicenter, randomized, double-blind, placebo-controlled trial

Kwon, Young W; Eisenberg, Gerald; Zuckerman, Joseph D
BACKGROUND: Nonoperative treatments for glenohumeral osteoarthritis (GH-OA) are limited. Intra-articular therapy with sodium hyaluronate (HA) has been effective in treating OA of the knee. Therefore, we sought to evaluate the efficacy and safety of HA in treating chronic pain associated with GH-OA. METHODS: This double-blind, randomized, controlled multicenter trial enrolled 300 patients with GH-OA: 150 received HA and 150 received phosphate-buffered saline (PBS) in 3 weekly injections and were evaluated over 26 weeks. Primary and secondary outcome measurements were visual analog scale (VAS) for pain and the percentage of Outcome Measures in Rheumatoid Clinical Trials-Osteoarthritis Research Society International (OMERACT-OARSI) high responders. RESULTS: In HA and PBS intent-to-treat (ITT) patients, there was a mean improvement from baseline in VAS of 19.88 mm and 16.29 mm at week 26, respectively. Similarly, the percentage of OMERACT-OARSI high responders in the HA group was higher (40.8% vs 34.9%); however, neither difference was statistically significant (P = .1121 and P = .0690, respectively). In a subset of patients without concomitant shoulder pathologies, the differences of VAS and OMERACT-OARSI high-responder rates between groups were 4.0 mm and 8.37%, respectively, which reached statistical significance. Safety analyses showed comparable rates of adverse events between groups, and neither group reported serious treatment-related adverse events. CONCLUSIONS: A numeric advantage, but without statistical significance, was found for HA ITT patients with GH-OA. Although data for a subset of HA patients without concomitant pathologies reached statistical significance, additional randomized trials are needed to confirm the clinical implication of this outcome.
PMID: 23333168
ISSN: 1058-2746
CID: 301132

Outcomes of open reduction and internal fixation of proximal humerus fractures managed with locking plates

Ong, Crispin C; Kwon, Young W; Walsh, Michael; Davidovitch, Roy; Zuckerman, Joseph D; Egol, Kenneth A
We conducted a study to evaluate the outcomes and complications of open reduction and internal fixation (ORIF) of 2-, 3-, and 4-part proximal humerus fractures using a standard management protocol with locking plates. Of 72 patients with acute proximal humerus fractures managed with ORIF and locking plates, 63 were available at the minimum follow-up of 1 year and met the inclusion criteria. At each follow-up, radiographs were reviewed for healing, hardware failure, osteonecrosis, shoulder range of motion, and DASH (Disabilities of the Arm, Shoulder, and Hand) scores; any complications were recorded. Mean age was 62 years and mean follow-up was 19 months. There were 12 two-part fractures, 42 three-part fractures, and 9 four-part fractures. Thirteen patients had complications. Mean shoulder forward elevation was 135; patients with complications had a significantly lower mean forward elevation (P=.002). DASH scores were significantly lower in patients without complications than in those with complications (P=.01). Although excellent outcomes can be achieved when locking plates are used to manage proximal humerus fractures, complications are possible. Physicians must weigh the functional outcome data when considering management options for these types of injuries.
PMID: 23365808
ISSN: 1078-4519
CID: 214172

Reverse total shoulder arthroplasty for failed shoulder arthroplasty

Patel, Deepan N; Young, Brett; Onyekwelu, Ikemefuna; Zuckerman, Joseph D; Kwon, Young W
INTRODUCTION: Shoulder arthroplasty provides excellent outcomes for most patients; however, a subset of these patients with a failed arthroplasty will require revision. Recently, the reverse total shoulder arthroplasty (rTSA) has been used in these difficult clinical situations. Therefore, we sought to examine our initial experience using rTSA as a treatment for failed shoulder arthroplasty. METHODS: During a 5-year period, 31 patients (mean age, 68.7 years) underwent rTSA for treatment of a failed shoulder arthroplasty and their presurgical and operative data were analyzed. Of the 31 patients, 28 were available for an average follow-up of 40.7 months. Their outcomes were assessed with American Shoulder and Elbow Surgeons (ASES), University of California-Los Angeles (UCLA), and Simple Shoulder Test (SST) scores, and the visual analog scale (VAS) for pain. RESULTS: Compared with preoperative status, there were statistically significant improvements in all outcome measurements, including the ASES (24.0 to 66.2), UCLA (7.4 to 23.5), SST (1.5 to 7.6), and VAS (7.0 to 2.6). Active forward elevation improved from 44 degrees preoperatively to 108 degrees postoperatively (P < .001). Results were rated as good or excellent by 19 patients (67.9%), satisfactory by 4 (14.3%), and unsatisfactory by 5 (17.8%). Among the types of failed arthroplasty, patients with failed TSA noted the greatest improvement in their outcome, but this improvement was not statistically significant. CONCLUSIONS: The data suggest that patients can expect improved functional outcome and decreased pain after revision of previous arthroplasty to rTSA and that this procedure can provide a reliable salvage option for a challenging clinical problem.
PMID: 22361717
ISSN: 1058-2746
CID: 180262

Kinematic analysis of dynamic shoulder motion in patients with reverse total shoulder arthroplasty

Kwon, Young W; Pinto, Vivek J; Yoon, Jangwhon; Frankle, Mark A; Dunning, Page E; Sheikhzadeh, Ali
BACKGROUND: Reverse total shoulder arthroplasty (rTSA) has been used to treat patients with irreparable rotator cuff dysfunction. Despite the proven clinical efficacy, there is minimal information regarding the underlying changes to the shoulder kinematics associated with this construct. Therefore, we sought to examine the kinematics of dynamic shoulder motion in patients with well-functioning rTSA. METHODS: We tested 12 healthy subjects and 17 patients with rTSA. All rTSA patients were able to elevate their arms to at least 90 degrees and received the implant as the primary arthroplasty at least 6 months before testing. On average, the rTSA patients elevated their arms to 112 degrees +/- 12 degrees (mean +/- SD) and reported an American Shoulder and Elbow Surgeons outcome score of 90.6 +/- 6.3. A 3-dimensional electromagnetic motion capture device was used to detect the dynamic motion of the trunk, scapula, and humerus during bilateral active shoulder elevation along the sagittal, scapular, and coronal planes. RESULTS: In both healthy and rTSA shoulders, the majority of the humeral-thoracic motion was provided by the glenohumeral motion. Therefore, the ratio of glenohumeral to scapulothoracic (ST) motion was always greater than 1.62 during elevation along the scapular plane. In comparison to healthy subjects, however, the contribution of ST motion to overall shoulder motion was significantly increased in the rTSA shoulders. This increased contribution was noted in all planes of shoulder elevation and was maintained when weights were attached to the arm. CONCLUSION: Kinematics of the rTSA shoulders are significantly altered, and more ST motion is used to achieve shoulder elevation.
PMID: 22036549
ISSN: 1058-2746
CID: 174365