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Dive into the research topics where George A. Kapetanos is active.

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Featured researches published by George A. Kapetanos.


Journal of Biomechanics | 2009

Validity of architectural properties of the hamstring muscles: Correlation of ultrasound findings with cadaveric dissection

Eleftherios Kellis; Nikiforos Galanis; Konstantinos Natsis; George A. Kapetanos

The purpose of this study was to compare the architectural parameters of the long head of biceps femoris (BFlh) and semitendinosus (ST) muscles by comparing measurements from ultrasound (US) with those obtained from direct dissection. The BFlh and ST architectures were examined bilaterally in 6 legs from 3 male cadavers. The fascicle length, pennation angle, muscle thickness and muscle and tendon length were obtained from direct measurement and US scans along each muscle. Intraclass correlation coefficients between the two methods ranged from 0.905 to 0.913 for the BFlh variables and from 0.774 to 0.974 for the ST parameters. Compared with the direct measurements, the US method showed a mean typical error of 0.09-0.14 cm for muscle thickness, 1.01-1.31 degrees for the pennation angle, 0.92-1.71 cm for fascicle length and muscle-tendon length measurements. The US method is a valid alternative tool for assessing basic architectural parameters of ST and BFlh components of the hamstring muscles.


Spine | 2009

Efficacy of Steroid and Nonsteroid Caudal Epidural Injections for Low Back Pain and Sciatica: A Prospective, Randomized, Double-blind Clinical Trial

Fares E. Sayegh; Eustathios Kenanidis; Kyriakos A. Papavasiliou; Michael Potoupnis; John M. Kirkos; George A. Kapetanos

Study Design. Prospective, double-blind, randomized, case-control study. Objective. To evaluate the efficacy of caudal epidural injections (CEI) containing steroid versus nonsteroid preparations when treating patients suffering from low back pain (LBP) and sciatica. Summary of Background Data. Literature seems to be deprived of well-designed randomized, controlled studies that evaluate the effectiveness of CEI in the treatment of chronic LBP; hence the value of CEI remains still the subject of controversy. Methods. Patients suffering from severe chronic LBP and sciatica were randomly allocated into 2 groups. Steroid-group’s patients (n = 93) underwent CEI containing 12 mL of xylocaine 2% and 1 mL of betamethasone dipropionate and betamethasone phosphate (2 + 5) mg/dL. Water for Injection (WFI)-group’s patients (n = 90) underwent CEI containing 12 mL of xylocaine 2% and 8 mL of WFI. Both groups were statistically comparable as far as their demographic data and the cause and duration of symptoms were concerned. Patients answered the Oswestry Disability Index questionnaire and underwent physical examination, before and at 1 week, 1 month, 6 months, and 1 year following the CEI. Results. Symptoms improved in 132 patients (72.1%) following CEI. The mean Oswestry Disability Index questionnaire score of steroid-group’s patients was statistically significant lower than that of the WFI-group at all postinjection re-evaluations. Patients receiving steroid CEI experienced faster relief during the first postinjection week. The Straight Leg Rising test improved in both groups following CEI; this improvement was faster among steroid-group’s patients. Fifty-one patients (27.8%), noticed no improvement 1 week post-CEI and underwent a second CEI (with the same preparation) 7 to 14 days later. Nineteen of them reported improvement; 32 (steroid-group:13, WFI-group:19) did not respond well and underwent operative decompression (n = 15) or spinal fusion (n = 17). Conclusion. CEI containing local anesthetic and steroids or WFI seems to be effective when treating patients with LBP and sciatica. CEI containing steroid preparations demonstrated better and faster efficacy.


Journal of Bone and Joint Surgery-british Volume | 2005

Brachial plexus palsy secondary to birth injuries: LONG-TERM RESULTS OF ANTERIOR RELEASE AND TENDON TRANSFERS AROUND THE SHOULDER

John M. Kirkos; Margaritis J. Kyrkos; George A. Kapetanos; J. H. Haritidis

We describe the long-term results in ten patients with obstetric brachial plexus palsy of anterior shoulder release combined with transfer of teres major and latissimus dorsi posteriorly and laterally to allow them to act as external rotators. Eight patients had a lesion of the superior trunk and two some involvement of the entire brachial plexus. The mean age at operation was six years, and the mean follow-up was 30 years. Before operation, the patients were unable actively to rotate the arm externally beyond neutral, although this movement was passively normal. All showed decreased strength of the external rotator, but had normal strength of the internal rotator muscles. Radiologically, no severe bony changes were seen in the glenohumeral joint. No clinically detectable improvement of active abduction was noted in any patient. The mean active external rotation after operation was 36.5°. This was maintained for a mean of ten years, and then deteriorated in eight patients. At the latest follow-up the mean active external rotation was 10.5°. The early satisfactory results of the procedure were not maintained. In the long term there was loss of active external rotation, possibly because of gradual degeneration of the transferred muscles, contracture of the surrounding soft tissues and degenerative changes in the glenohumeral joint.


Arthroscopy | 2009

Histomorphologic Study of Discoid Meniscus

Anestis Papadopoulos; John M. Kirkos; George A. Kapetanos

PURPOSE The purpose of this study was to investigate the matrix collagen network of the discoid lateral meniscus in comparison with normal lateral meniscus. METHODS Discoid meniscus samples obtained arthroscopically from 10 patients with a diagnosis of intact complete-type discoid lateral meniscus by a technique of excision in 1 piece were examined histomorphologically regarding the integrity of both main collagen fiber systems, radial and circular, because they have been described in the structure of normal knee meniscus. As a control group, intact lateral menisci excised during knee arthroplasty procedures were used. RESULTS Histomorphologic scoring showed statistically significant disorganization of the circular collagen network in the discoid meniscus group compared with the normal meniscus group, especially along the posterior third of the specimen (P < .001). In addition, a heterogeneous course of the circumferentially arranged collagen fibers was shown in the discoid meniscus structure. CONCLUSIONS Findings of discontinuity and inhomogeneity of the circumferential collagen network in the discoid meniscus in comparison with normal meniscus indicate that the discoid lesion represents a structural lesion rather than a morphologic variant. CLINICAL RELEVANCE Disorganization of the circular collagen fiber system in the discoid meniscus matrix may contribute to the pathogenesis of the high tear and degenerative lesion rate observed among menisci with discoid configuration.


Journal of Shoulder and Elbow Surgery | 2012

Radial head replacement with the MoPyC pyrocarbon prosthesis

Ioannis K. Sarris; Margaritis J. Kyrkos; Nikiforos Galanis; Kyriakos A. Papavasiliou; Fares E. Sayegh; George A. Kapetanos

BACKGROUND Radial head fractures often pose therapeutic dilemmas. We present the early results of patients who underwent radial head replacement with the MoPyC prosthesis (Bioprofile, Tornier, Saint-Ismier, France). MATERIALS AND METHODS We re-evaluated patients who underwent post-traumatic radial head resection and implantation of the MoPyC prosthesis due to pain and motion restriction. All patients underwent radiographic evaluation. Clinical evaluation was performed using the Broberg-Morrey and the Mayo Elbow Performance Score (MEPS) scales. RESULTS Thirty-two patients (20 men, 12 women; mean age, 54 years; 22 dominant upper limbs) were evaluated. Twenty had a comminuted radial head fracture (Mason IV, 15; Mason III, 5), 2 from radial head fracture malunion, and 10 had complex elbow injuries (comminuted radial head fractures with ligamentous ruptures with or without coronoid process fractures). Mean follow-up was 27 months (range, 21-46 months). The mean results at the latest follow-up were flexion-extension, 130° (range, 105°-150°); pronation, 74° (range, 60°-80°); and supination, 72° (range, 60°-80°). No laxity was evident during valgus and varus stress tests. Mean grip strength was 96% of the contralateral side. Broberg-Morrey scores were excellent in 33%, good in 44%, and fair in 23%. MEPS results were excellent in 80%, good in 17%, and fair in 3%. There were 6 cases of periprosthetic lucencies or osteolysis of the radius without any clinical signs of loosening. CONCLUSIONS Radial head replacement with the MoPyC pyrocarbon prosthesis (when performed in carefully selected patients) yields satisfactory results regarding range of motion and function of the elbow joint.


Journal of Arthroplasty | 2009

The Effectiveness of the Burch-Schneider Antiprotrusio Cage for Acetabular Bone Deficiency: Five to Twenty-one Years' Follow-up

Panagiotis P. Symeonides; George Petsatodes; John Pournaras; George A. Kapetanos; Anastasios Christodoulou; Dimitrios J. Marougiannis

From 1985 to 2001, the Burch-Schneider antiprotrusio cage (B-S APC) was implanted in 57 cases (55 patients) with massive acetabular deficiency. The B-S APC survived until the last review 5 to 21 years after operation in 89.5% of the cases, produced substantial pain relief, and increased range of hip motion and walking capacity. The 10.5% failure rate was due to aseptic loosening in 2 cases and mechanical failure in 4 cases. It appears that application of the B-S APC in extensive acetabular deficiency presents a durable solution provided that proper indications and technique are used.


European Spine Journal | 2006

Thoracic cord compression caused by disk herniation in Scheuermann’s disease: A case report and review of the literature

George A. Kapetanos; Paraskevas T. Hantzidis; Kleovoulos Anagnostidis; John M. Kirkos

We present the case of a 14-year-old male with Scheuermann’s disease and significant neurological deficit due to thoracic disk herniation at the apex of kyphosis. He was treated with an anterior decompression, anterior and posterior fusion in the same setting using plate, cage and a segmental instrumentation system. The patient had an excellent outcome with complete neurological recovery.


Journal of Electromyography and Kinesiology | 2010

Muscle architecture variations along the human semitendinosus and biceps femoris (long head) length

Eleftherios Kellis; Nikiforos Galanis; Konstantinos Natsis; George A. Kapetanos

The purpose of this study was to examine whether muscle architecture of the long head of biceps femoris (BF) and semitendinosus (ST) muscles varies along their length. The ST and BF muscles were dissected and removed from their origins in eight cadaveric specimens (age range 67.8-73.4 years). One-way analysis of variance designs were used to compare fascicle length (FL), pennation angle (PA) and muscle thickness (MT) between proximal, mid-belly and distal positions. Tendon and muscle length properties were also quantified. For the BF muscle, one-way analysis of variance tests showed a higher PA (23.96±3.82°) and FL (7.12±0.48 cm) proximally than distal positions (PA=17.78±1.95° and FL=6.35±0.89 cm, respectively). For the ST, there was a significantly (p<0.05) lower PA (8.81±1.22°) and FL (13.10±1.54 cm) proximally than distally (PA=14.69±1.09° and FL=15.49±2.30 cm, respectively). Muscle thickness significantly increased from distal to more proximal positions (p<0.05). These data suggest that the ST and BF architecture is not uniform and that measurement of these parameters largely depends on the measurement site. Modeling these muscles by assuming a uniform architecture along muscle length may yield less accurate representation of human hamstring muscle function.


Journal of Electromyography and Kinesiology | 2012

Architectural differences between the hamstring muscles

Eleftherios Kellis; Nikiforos Galanis; George A. Kapetanos; Konstantinos Natsis

The purpose of this study was to understand the detailed architectural properties of the human hamstring muscles. The long (BFlh) and short (BFsh) head of biceps femoris, semimembranosus (SM) and semitendinosus (ST) muscles were dissected and removed from their origins in eight cadaveric specimens (age 67.8±4.3 years). Mean fiber length, sarcomere length, physiological cross-section area and pennation angle were measured. These data were then used to calculate a similarity index (δ) between pairs of muscles. The results indicated moderate similarity between BFlh and BFsh (δ=0.54) and between BFlh and SM (δ=0.35). In contrast, similarity was low between SM and ST (δ=0.98) and between BFlh and SM (δ=1.17). The fascicle length/muscle length ratio was higher for the ST (0.58) and BFsh (0.50) compared with the BFlh (0.27) and SM (0.22). There were, however, high inter-correlations between individual muscle architecture values, especially for muscle thickness and fascicle length data sets. Prediction of the whole hamstring architecture was achieved by combining data from all four muscles. These data show different designs of the hamstring muscles, especially between the SM and ST (medial) and BFlh and BFsh (lateral) muscles. Modeling the hamstrings as one muscle group by assuming uniform inter-muscular architecture yields less accurate representation of human hamstring muscle function.


Spine | 2008

Adolescent idiopathic scoliosis and exercising: is there truly a liaison?

Eustathios Kenanidis; Michael Potoupnis; Kyriakos A. Papavasiliou; Fares E. Sayegh; George A. Kapetanos

Study Design. Cross-sectional observational study. Objective. Evaluation and comparison of the prevalence of adolescent idiopathic scoliosis (AIS) among 2 groups of patients (athletes and nonathletes) to determine whether athletic activities are related to the development of AIS. Summary of Background Data. The potential association between AIS and exercising remains uncertain. The latter has often been considered as a therapeutic means and a causative factor of the former. Methods. A group of 2387 adolescents (boys: 1177, girls: 1210, mean age: 13.4 years) was evaluated. All completed a questionnaire concerning personal, somatometric, and secondary sex characteristics, type, duration and character of daily-performed physical activities, and existing cases of AIS among relatives. Patients were classified into 2 groups according to their answers; “athletes” and “nonathletes.” The groups were comparable as far as age, height, weight, onset of menstruation, family history of scoliosis, and side of handedness were concerned. Children underwent physical examination by 3 orthopedic surgeons who were unaware of their level of athletic activities. Children considered, by all, to be suspicious of suffering from scoliosis, underwent further radiographic evaluation. Results. In 99 cases (athletes: 48, nonathletes: 51), AIS was radiographically confirmed (Cobb angle >10°). No statistically significant difference was found between athlete and nonathlete adolescents (P = 0.842), athlete and nonathlete boys (P = 0.757), and athlete and nonathlete girls (P = 0.705), as far as the prevalence of AIS was concerned. The mean value of the Cobb angle of the main scoliotic curve was not statistically different between male athletes and nonathletes (P = 0.45) and female athletes and nonathletes (P = 0.707). With the Cobb threshold reset at 20°, no statistically significant differences were detected either. Conclusion. Our results demonstrate that systematic exercising is probably not associated with the development of AIS. Actively participating in sports activities doesn’t seem to affect the degree of the main scoliotic curve either.

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Kyriakos A. Papavasiliou

Aristotle University of Thessaloniki

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Fares E. Sayegh

Aristotle University of Thessaloniki

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John M. Kirkos

Aristotle University of Thessaloniki

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Michael Potoupnis

Aristotle University of Thessaloniki

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Eustathios Kenanidis

Aristotle University of Thessaloniki

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Margaritis J. Kyrkos

Aristotle University of Thessaloniki

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Nikiforos Galanis

Aristotle University of Thessaloniki

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John Pournaras

Aristotle University of Thessaloniki

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Anastasios Christodoulou

Aristotle University of Thessaloniki

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Ioannis K. Sarris

Aristotle University of Thessaloniki

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