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Dive into the research topics where Anton Y. Plakseychuk is active.

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Featured researches published by Anton Y. Plakseychuk.


American Journal of Sports Medicine | 2005

Varying Femoral Tunnels Between the Anatomical Footprint and Isometric Positions Effect on Kinematics of the Anterior Cruciate Ligament–Reconstructed Knee

Volker Musahl; Anton Y. Plakseychuk; Andrew VanScyoc; Tomoyuki Sasaki; Richard E. Debski; Patrick J. McMahon; Freddie H. Fu

Background Knee kinematics and in situ forces resulting from anterior cruciate ligament reconstructions with 2 femoral tunnel positions were evaluated. Hypothesis A graft placed inside the anatomical footprint of the anterior cruciate ligament will restore knee function better than a graft placed at a position for best graft isometry. Study Design Controlled laboratory study. Methods Ten cadaveric knees were tested in response to a 134-N anterior load and a combined 10-N·m valgus and 5-N·m internal rotation load. A robotic universal force-moment sensor testing system was used to apply loads, and resulting kinematics were recorded. An active surgical robot system was used for positioning tunnels in 2 locations in the femoral notch: inside the anatomical footprint of the anterior cruciate ligament and a position for best graft isometry. The same quadrupled hamstring tendon graft was used for both tunnel positions. The 2 loading conditions were applied. Results At 30° of knee flexion, anterior tibial translation in response to the anterior load for the intact knee was 9.8 ± 3.1 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 13.8 ± 4.6 mm; position 2: 16.6 ± 3.7 mm; P <. 05). There was a significant difference between the 2 tunnel positions. At the same flexion angle, the anterior tibial translation in response to the combined load for the intact knee was 7.7 ± 4.0 mm. Both femoral tunnel positions resulted in significantly higher anterior tibial translation (position 1: 10.4 ± 5.5 mm; position 2: 12.0 ± 5.2 mm; P <. 05), with a significant difference between the tunnel positions. Conclusion Neither femoral tunnel position restores normal kinematics of the intact knee. A femoral tunnel position inside the anatomical footprint of the anterior cruciate ligament results in knee kinematics closer to the intact knee than does a tunnel position located for best graft isometry. Clinical Relevance Anatomical femoral tunnel position is important in reproducing function of the anterior cruciate ligament.


Journal of Bone and Joint Surgery, American Volume | 2003

Vascularized Compared with Nonvascularized Fibular Grafting for the Treatment of Osteonecrosis of the Femoral Head

Anton Y. Plakseychuk; Shin-Yoon Kim; Byung-Chul Park; Sokratis E. Varitimidis; Harry E. Rubash; Dean G. Sotereanos

Background: We are not aware of any clinical studies in the literature comparing the results of vascularized and nonvascularized fibular grafting for the treatment of osteonecrosis of the femoral head. The purpose of this study was to compare the clinical results of free vascularized fibular grafting with those of nonvascularized fibular grafting.Methods: Two hundred patients (220 hips) with osteonecrosis of the femoral head were treated with free vascularized fibular grafting at the University of Pittsburgh Medical Center, and ninety-nine patients (123 hips) were treated with nonvascularized fibular grafting at the Kyungpook National University Hospital in Korea. From these populations, two groups of fifty hips each, followed for a minimum of three years (average, five years), were matched by the stage, size, and etiology of the lesion and by the mean preoperative Harris hip score. A retrospective case-control study of these groups was then performed to compare the postoperative Harris hip scores as well as the prevalences of radiographic progression and collapse of the femoral head following free vascularized fibular grafting with those measures following nonvascularized fibular grafting.Results: The mean Harris hip score improved for 70% of the hips treated with free vascularized fibular grafting: seventeen hips (34%) were rated excellent, fourteen (28%) were rated good, nine (18%) were rated fair, and ten (20%) were rated poor. The mean Harris hip score improved for 36% of the hips treated with nonvascularized fibular grafting: five hips (10%) were rated excellent; nine (18%), good; sixteen (32%), fair; and twenty (40%), poor. The rate of survival at seven years for the Stage-I and II hips (precollapse) was 86% after treatment with free vascularized fibular grafting compared with 30% after nonvascularized fibular grafting.Conclusions: The results of this study strongly suggest that vascularized fibular grafting is associated with better clinical and radiographic results.Level of Evidence: Therapeutic study, Level III-2 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.


Clinical Orthopaedics and Related Research | 1997

Free vascularized fibula grafting for the treatment of osteonecrosis of the femoral head.

Dean G. Sotereanos; Anton Y. Plakseychuk; Harry E. Rubash

Sixty-five patients (88 hips) who received free vascularized fibula grafting for treatment of osteonecrosis of the femoral head at the University of Pittsburgh Medical Center, were followed for at least 3 years (average followup, 5.5 years; range, 3-7 years). There were 46 men and 19 women with an average age of 37 years (range, 20-52 years). All patients were evaluated using history, physical examination, Harris Hip Score, anteroposterior and lateral radiographs, and magnetic resonance images. The classification system of Steinberg et al (1995) was used to stage the disease. At final evaluation, 31 hips (35.2%) were rated excellent (Harris Hip Score > 90 points, minimal or no pain), 30 hips (34.1%) were rated good (Harris Hip Score 80-89 points, slight pain), seven hips (8%) were rated fair (Harris Hip Score 70-79, slight or moderate pain), and 20 hips (22.7%) were rated poor (Harris Hip Score < 70, pain). Twenty hips in 17 patients required total hip arthroplasty. In the remaining hips, the disease apparently arrested and the contour of the femoral head was preserved. Kaplan-Meier survivorship analyses showed that the probability of conversion to total hip arthroplasty within an average of 5.5 years after free vascularized fibula grafting was 28% for Stage II hips and 38% for Stages III and IV hips. The hip survival rate for subgroups at 5.5 years was 100% for Stages IC and IIA, 94% for Stage IIB, 50% for Stage IIC, 80% for Stage IIIB, 58% for Stage IIIC, 72% for Stage IVA, and 58% for Stage IVB. Free vascularized fibula grafting is a reliable operation and can preserve hip function and diminish pain successfully.


Clinical Orthopaedics and Related Research | 2001

Classification of osteonecrosis of the femoral head. Reliability, reproducibility, and prognostic value.

Anton Y. Plakseychuk; Munir Shah; Sokratis E. Varitimidis; Harry E. Rubash; Dean G. Sotereanos

The purpose of the current investigation was to determine interobserver and intraobserver reliability of the classification system of Steinberg et al for osteonecrosis of the femoral head. Sixty-five anteroposterior and lateral radiographs of hips were selected randomly from a pool of patients with confirmed osteonecrosis of the femoral head. Six fellowship-trained observers viewed the radiographs (Reading 1). The observers used six main stages of the classification excluding A, B, and C subgroups. The same observers viewed the radiographs 4 months later in reverse order (Reading 2). Reading 1 was used to calculate interobserver kappa values. Reading 2 was used to calculate intraobserver kappa values. Stage-specific kappa values for interobserver variation between all viewers were as follows: Stage I, k = 0.64; Stage II, k = 0.51; Stage III, k = 0.21; Stage IV, k = 0.49; Stage V, k = 0.36; and Stage VI, k = 0.80. Stage-specific kappa values for intraobserver variation between all viewers were as follows: Stage I, k = 0.74; Stage II, k = 0.60; Stage III, k = 0.46; Stage IV, k = 0.59; Stage V, k = 0.27; and Stage VI, k = 0.78. An average of 10 of 21 (48%) of these errors involved Stage III. An average of 6.3 of 21 (30%) intraobserver errors involved Stage V. The presence of the crescent sign in Stage III and joint space narrowing in Stage V markedly diminished the overall reliability of any four-to six-stage classification system. Based on the authors’ experience and analysis of the current classifications of osteonecrosis of the femoral head, an easy and reproducible Pittsburgh classification system is proposed.


Journal of Hand Surgery (European Volume) | 2000

The Compass Elbow Hinge: Indications and Initial Results

R. J. Fox; Sokratis E. Varitimidis; Anton Y. Plakseychuk; Dimitris G. Vardakas; Matthew M. Tomaino; Dean G. Sotereanos

The Compass Elbow Hinge uses Illizarov’s methods of fixation to externally hold the elbow reduced and allow both passive and active motion. Eleven patients with degenerative disease, contracture or instability were treated with the Compass Elbow Hinge and were retrospectively evaluated at an average follow-up of 29 months (range: 18–62 months). One was lost to follow-up. Patients with degenerative changes underwent fascia lata interposition while those treated for contractures underwent anterior and posterior capsular release with or without fascia lata interposition. Those with elbow instability underwent ligament reconstruction. The device was removed after 6 weeks and seven of the 11 patients were satisfied with the outcome of the operation. Stability could not be achieved in two patients with coronoid fractures that were not reconstructed. One patient did not tolerate the device and requested its removal with subsequent subluxation. We conclude that patient selection and compliance are key elements in achieving a satisfactory outcome with the device.


Journal of Arthroplasty | 2015

Topical versus intravenous tranexamic acid in total knee arthroplasty

Brian R. Hamlin; Anthony M. DiGioia; Anton Y. Plakseychuk; Tim J. Levison

The objective of this study is to compare the effectiveness of intravenous versus topical application of tranexamic acid in patients undergoing knee arthroplasty. All patients who underwent primary knee arthroplasty at our total joint center over a 12-month period were included in the study. One surgeon utilized 1 g of IV TXA at time of incision in all patients (n=373) except those with a documented history of venous thromboembolism (VTE). Two surgeons utilized a topical application of TXA for all patients without exception (n=198) in which the joint was injected after capsular closure with 3 g TXA/100 mL saline. The transfusion rate was 0% in the topical group vs. 2.4% in the IV group and this was statistically significant (P<0.05).


Journal of Hand Surgery (European Volume) | 1998

Identification and Preservation of Palmar Cutaneous Nerves During Open Carpal Tunnel Release

Matthew M. Tomaino; Anton Y. Plakseychuk

We looked for crossing cutaneous nerve branches during standard open carpal tunnel release and attempted to preserve them. Open carpal tunnel release was performed on 34 hands in 29 patients. Crossing cutaneous nerves were identified in 47% of hands and successfully preserved in each case. No patient experienced postoperative pillar pain or scar hypersensitivity.


Sports Medicine | 2002

Current opinion on computer-aided surgical navigation and robotics: role in the treatment of sports-related injuries.

Volker Musahl; Anton Y. Plakseychuk; Freddie H. Fu

AbstractComputer-assisted surgery (CAS) may allow surgeons to be more precise and minimally invasive, in addition to being an excellent research tool. Medical imaging, such as magnetic resonance and computed tomography is not only an important diagnostic tool, but also a necessary planning tool. In orthopaedic sports medicine, precision is needed when placing tunnels for soft tissue fixation of replacement grafts. Two types of CAS systems — passive and active — have been developed. Passive systems, or surgical navigation systems, provide the surgeon with additional information prior to and during the surgical procedure (in real time). Active systems have the ability of performing certain surgical steps autonomously. Both active and passive CAS systems are currently a subject of basic science and clinical investigations and will be discussed and commented on in this article. In summary, passive navigation systems can provide additional information to the surgeon and can therefore lead to more precise tunnel placement. Active robotic technology seems to be accurate and feasible with promising initial results from Europe. However, active and passive CAS can only be as precise as the surgeon who plans the procedure. Therefore, future studies have to focus on integrating, arthroscopy, 3-D image-enhanced computer navigation, and virtual kinematics, as well as to increase precision in surgical techniques.


Journal of Clinical Anesthesia | 2010

The role of surgery in postoperative nerve injuries following total hip replacement.

Jacques E. Chelly; Anna Uskova; Anton Y. Plakseychuk

Although postoperative nerve injury is infrequent in patients undergoing joint replacement, it is extremely distressing for the patient, surgeon, and anesthesiologist. The nature of nerve injury is often closely related to the type of surgery; this review details the potential surgical causes of nerve injuries following total hip arthroplasty. The current orthopedic literature (1943-2008) was reviewed to help anesthesiologists better understand the pathophysiology of surgery-related postoperative nerve injuries, including the relationship with hip joint anatomy and the surgical techniques.


Journal of Hand Therapy | 1999

Reconstruction of the elbow: Surgeons' perspective

Sokratis E. Varitimidis; Anton Y. Plakseychuk; Dean G. Sotereanos

Great progress has been made in surgery of the elbow during the past decade. Better definition of ligamentous anatomy, recognition of previously undescribed instability patterns, and development of ligament reconstruction techniques have helped improve surgery designed to restore stability of the elbow. Surgical release of elbow contractures helps patients with stiffness gain very satisfactory range of motion. New techniques and advances in prostheses have broadened the indications for total elbow arthroplasty, and cases that were previously considered inoperable can now be treated surgically with excellent outcomes. Elbow surgery enters the new millennium having accomplished much, but problems and challenges remain.

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Freddie H. Fu

University of Pittsburgh

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Branislav Jaramaz

Carnegie Mellon University

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