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Featured researches published by Nikolaos Roidis.


Clinical Orthopaedics and Related Research | 2002

Periprosthetic total hip infection: outcomes using a staging system.

Edward J. McPherson; Chris Woodson; Paul Holtom; Nikolaos Roidis; Chrissandra Shufelt; Michael J. Patzakis

The outcomes of 50 consecutive patients with chronic periprosthetic total hip arthroplasty infections were evaluated based on a staging system developed at the authors’ institution. The staging system includes three categories: infection type (acute versus chronic), systemic host grade, and local extremity grade. The initial treatment plan was a two-stage resection followed by reimplantation if clinically indicated. Treatment was modified for each patient according to how the patient responded to initial debridement. The average followup was 23.2 months (range, 0–74 months). Of the 50 patients, 29 had reimplantation with a total hip arthroplasty (58%), 17 patients had permanent resections (34%), and four patients had amputations (8%). Five patients died (10%). Fifteen patients had muscle flap transfers into the hip for soft tissue coverage. Significant correlations were seen with the staging system and outcome parameters. Patients who were very medically ill were far more likely to die or have their leg amputated. Conversely, healthier patients were more likely to have successful reimplantation. A strong correlation was seen with a compromised local wound and the need for muscle flap transfer. Complication rates were strongly related to worsening medical condition and a worsening local wound. Based on these results, a staging system for periprosthetic infection is a useful tool that with additional refinement will provide more objective evaluation of treatment methods for periprosthetic hip infection in the future.


Journal of Bone and Joint Surgery-british Volume | 2008

Total knee replacement performed with either a mini-midvastus or a standard approach: A PROSPECTIVE RANDOMISED CLINICAL AND RADIOLOGICAL TRIAL

Th. Karachalios; D. Giotikas; Nikolaos Roidis; L. Poultsides; K. Bargiotas; K. Malizos

We report the clinical and radiological results of a two- to three-year prospective randomised study which was designed to compare a minimally-invasive technique with a standard technique in total knee replacement and was undertaken between January 2004 and May 2007. The mini-midvastus approach was used on 50 patients (group A) and a standard approach on 50 patients (group B). The mean follow-up in both groups was 23 months (24 to 35). The functional outcome was better in group A up to nine months after operation, as shown by statistically significant differences in the mean function score, mean total score and the mean Oxford knee score (all, p = 0.05). Patients in group A had statistically significant greater early flexion (p = 0.04) and reached their greatest mean knee flexion of 126.5 degrees (95 degrees to 135 degrees ) 21 days after operation. However, at final follow-up there was no significant difference in the mean maximum flexion between the groups (p = 0.08). Technical errors were identified in six patients from group A (12%) on radiological evaluation. Based on these results, the authors currently use minimally-invasive techniques in total knee replacement in selected cases only.


Spine | 1999

Ten-year follow-up evaluation of a school screening program for scoliosis. Is the forward-bending test an accurate diagnostic criterion for the screening of scoliosis?

Theofilos Karachalios; John Sofianos; Nikolaos Roidis; George Sapkas; Dimitrios S. Korres; K. Nikolopoulos

STUDY DESIGN A 10-year follow-up evaluation of the effectiveness of school screening for scoliosis performed in a closed island population. OBJECTIVES To evaluate the diagnostic accuracy of methods used for screening scoliosis and to re-examine the long-term effectiveness of the school scoliosis screening program. SUMMARY OF BACKGROUND DATA The diagnostic accuracy of the forward-bending test and the long-term efficacy of the screening programs have not been clearly established. METHODS In 1987, 2700 pupils aged 8 to 16 years from the island of Samos were screened for scoliosis. The Adams forward-bending test, Moire topography, the scoliometer, and the humpometer were used. Radiologic evaluation of the spine was available for each pupil and the number of false-negative and false-positive results of the screening methods was calculated. Subsequently, sensitivity, specificity, and positive and negative predictive values were estimated for each screening technique. Pupils found positive for spinal deformity were then followed up regularly at yearly intervals. In 1997, all positive subjects attended a 10-year clinical and radiologic follow-up, and the remaining subjects were re-evaluated by a postal questionnaire and were clinically examined if necessary. RESULTS Spinal deformity was found in 153 (5.66%) pupils. Scoliosis (defined as a spinal curvature > or = 10 degrees) was found in 32 pupils, for a prevalence of 1.18%. For scoliosis, the Adams forward-bending test showed a number of false-negative results (in five cases), for a sensitivity of 84.37% and specificity of 93.44%. The sensitivities of Moire topography, the humpometer, and the scoliometer were 100%, 93.75%, and 90.62%, respectively, and specificity was 85.38%, 78.11%, and 79.76% respectively. The negative predictive value of the forward-bending test was inferior to those of the other methods. During this scoliosis screening program, if cutoff limits for referral had been used, such as the asymmetry of two Moire fringes, a humpogram deformity of (D + H) = 10 mm, and 8 degrees of scoliometer angle, it would have been possible to reduce radiologic examination by 89.4%. Three (0.11%) pupils aged between 12 and 14 years with scoliotic deformities greater than 20 degrees underwent satisfactory nonoperative treatment with Boston braces. One pupil with a 40 degrees thoracic curvature, underwent satisfactory surgical treatment because of progression 1 year later. Of the 121 spinal deformities with an initial Cobb angle less than 10 degrees, 44 (35.8%), and of the 29 scoliotic deformities with an initial Cobb angle between 10 degrees and 20 degrees, 14 (48.3%) progressed (a Cobb angle difference of at least 5 degrees in more than one examination). Observation and physiotherapy were the only treatments applied to all except one of the pupils in these groups. CONCLUSIONS The Adams forward-bending test cannot be considered a safe diagnostic criterion for the early detection of scoliosis (especially when it is used as the only screening tool) because it results in an unacceptable number of false-negative findings. For the early detection of scoliosis, a combination of back-shape analysis methods can be safely used with the introduction of cutoff limits for referral being a useful procedure. The incidence of significant scoliosis is low, and its natural history seems to be independent of early detection. The wide-spread use of school scoliosis screening with the use of the forward-bending test must be questioned.


The Clinical Journal of Pain | 1999

Analgesic effect of Salmon calcitonin suppositories in patients with acute pain due to recent osteoporotic vertebral crush fractures : A prospective double-blind, randomized, placebo-controlled clinical study

G. Lyritis; George Ioannidis; Th. Karachalios; Nikolaos Roidis; E. Kataxaki; N. Papaioannou; J. Kaloudis; Antonis Galanos

OBJECTIVE To evaluate the analgesic efficacy of calcitonin suppositories (200 IU) in comparison with bed rest and paracetamol tablets, as a rescue analgesic. DESIGN A prospective, double-blind, randomized, placebo-controlled, clinical trial. PATIENTS Forty patients (8 men and 32 postmenopausal women), who had recently (within the last 5 days) suffered a nontraumatic osteoporotic vertebral fracture. SETTING AND INTERVENTIONS All patients were admitted to the hospital, divided randomly into two groups and received either one calcitonin or placebo suppository once a day, respectively, for 28 days. All patients were allowed to take paracetamol tablets (500 mg), with a maximum dose of six tablets daily. OUTCOME MEASURES Spinal pain evaluation was performed at the beginning of the study (before the initiation of treatment) and then daily until the end of the study (day 28) using the Huskinssons visual analog scale (VAS) and a painmeter device, by direct pressure on the fractured vertebra. Pain was evaluated with the patients attempting or performing four different locomotor functions, e.g., bed rest, sitting, standing, and walking functions. Biochemical urine and plasma measurements were carried out before the initiation of treatment and on days 14 and 28. RESULTS All calcitonin-treated patients experienced an overall statistically significant (all p values < 0.001) decrease of spinal pain as assessed by the VAS and the painmeter device. Pain relief allowed for early mobilization and the gradual restoration of the locomotive functions in the calcitonin-treated group. Placebo-treated patients remained in bed for almost the whole of the observation period. At the end of the study (28th day), fasting osteocalcin, hydroxyproline/creatinine, and calcium/creatinine ratio values were statistically significantly (all p values < 0.001), lower in the calcitonin-treated than in the placebo-treated patients. In the placebo group these values showed a gradual increase. In the calcitonin-treated group side effects mainly included dizziness and enteric irritation caused by the suppositories. Enteric irritation was also present in the placebo-treated group. CONCLUSIONS Salmon calcitonin suppositories (200 IU daily) caused a dramatic decrease in spinal pain in patients with recent osteoporotic vertebral fractures and influenced the early mobilization and the gradual restoration of their locomotor functions.


Knee | 2009

A mid-term clinical outcome study of the Advance Medial Pivot knee arthroplasty

Theofilos Karachalios; Nikolaos Roidis; Dimitrios Giotikas; Konstantinos Bargiotas; Socrates Varitimidis; Konstantinos N. Malizos

The Advance Medial Pivot Total Knee Arthroplasty (Wright Medical Technology, Arlington, Tennessee, USA) has been designed to reproduce modern ideas of knee kinematics. We report a prospective clinical outcome study of 284 arthroplasties in 225 consecutive patients with a mean follow-up of 6.7 years (range 4 to 9 years). For evaluation, both objective and subjective clinical rating systems and serial radiographs were used. At final follow-up, 10 (4.4%) patients (10 knees) only were lost from follow-up and four (1.8%) patients (five knees) had died for reasons unrelated to the surgery with their knees performing well. There was an 82% compliance in the intervals of follow-up evaluation. All patients showed a statistically significant improvement (p=0.01) in the Knee Society clinical rating system, WOMAC questionnaire, SF-12 questionnaire, and Oxford knee score. The majority of patients (92%) were able to perform age-appropriate activities with a mean knee flexion of 117 degrees (range 85 degrees to 135 degrees) at final follow-up. Survival analysis showed a cumulative success rate of 99.1% at 5 years. Two (0.7%) arthoplasties, in which patient selection and surgical errors were identified, were revised due to aseptic loosening, one due to infection and one due to a traumatic dislocation. This study demonstrates satisfactory mid-term clinical results for this knee design.


Foot & Ankle International | 2003

Position of the distal fibular fragment in pronation and supination ankle fractures: a CT evaluation.

Chris W. Tang; Nikolaos Roidis; Suketu Vaishnav; Anand Patel; David B. Thordarson

Background: Although classically the fibula has been reported to be in external rotation after supination-external rotation (SER) or pronation-external rotation (PER) ankle fractures, a previous CT study demonstrated that what had traditionally been interpreted as external rotation of the distal fibular fracture fragment is actually internal rotation of the proximal fibular fragment. The purpose of this study was to evaluate a series of CT scans in patients who have suffered type IV SER or PER ankle fractures to assess the rotational deformity of the fibular fragment. Materials and Methods: CT scans of the injured and uninjured extremities were performed on 30 extremities which had sustained either SER (21) or PER (9) injuries. The rotational relationship between the tibia and fibula was determined by a measured rotational ratio. A qualitative assessment of the rotational relationship between the tibia and fibula above, at, and below the fracture site at the level of the mortise was also performed. The difference in the ratio (calculated by subtracting the rotation ratio of the normal side from the fracture side) demonstrated whether the fractured fibula is externally or internally rotated compared to the uninjured side. Results: The average rotational ratio difference above the fracture compared to below the fracture for the SER group demonstrated significant external rotation (p < .001). The PER fracture also demonstrated external rotation of the distal fragment compared to the proximal fragment (p = .002). Additionally, qualitative assessment of the relationship demonstrated no obvious change in the rotational relationship in any patient above the fracture site except one where mild internal rotation of the proximal fragment was noted. However, at the level of the mortise, all had a normal talofibular rotational relationship while 24 of 30 had widening of the medial clear space with external rotation clearly evident on 15 of these 24 scans. Conclusion: Our study demonstrated that the distal fibular fragment in both SER and PER fractures is externally rotated relative to both the contralateral normal side and compared to the proximal fibular fragment.


Journal of Bone and Joint Surgery-british Volume | 2004

The effects of calcitonin on acute bone loss after pertrochanteric fractures A PROSPECTIVE, RANDOMISED TRIAL

Theofilos Karachalios; G. Lyritis; J. Kaloudis; Nikolaos Roidis; M. Katsiri

We investigated the effect of calcitonin in the prevention of acute bone loss after a pertrochanteric fracture and its ability to reduce the incidence of further fractures in the same patient. Fifty women aged between 70 and 80 years who had a pertrochanteric fracture of the hip were randomly allocated to group A (200 IU of nasal salmon calcitonin daily for three months) or group B (placebo). Patients in group A showed a significantly higher level of total alkaline phosphatase and osteocalcin on the 15th day after injury and a significantly higher level of bone alkaline phosphatase on the 90th day after surgery. These patients also had significantly lower levels of urinary C-telopeptide (CrossLaps) on the 15th, 45th and 90th days after injury and lower levels of urinary hydroxyproline on the 15th and 45th days after injury. Patients in group A had significantly higher bone mineral density at all recorded sites except the greater trochanter at three months and one year after operation. After a four-year period of clinical observation, five patients (24%) in group B sustained a new fracture, in four of whom (20%) it was of the contralateral hip. Our findings show that calcitonin reduces acute bone loss in patients with pertrochanteric fractures and may prevent the occurrence of new fractures of the contralateral hip in the elderly.


Clinical Orthopaedics and Related Research | 2004

Structural properties of the axis studied in cadaveric specimens

Dimitrios S. Korres; Theofilos Karachalios; Nikolaos Roidis; Vassilios Lycomitros; Chara A. Spiliopoulou; George P. Lyritis

Peripheral quantitative computed tomography scans of the axis in 20 fresh cadaveric specimens obtained at autopsy were studied to investigate the internal structural properties of the axis. In all specimens, serial scans were done in three planes. The area of the dens consisted of dense cortical and trabecular bone (Region 1, above the base of the dens) and showed statistically significantly greater peripheral quantitative computed tomography values when compared with the anterior part of the body of the axis (Region 2, below the base of the dens). An age-related progressive decrease of peripheral quantitative computed tomography values was observed, with specimens from subjects younger than 40 years showing statistically significantly greater peripheral quantitative computed tomography values when compared with those from subjects older than 40 years. A small area of trabecular bone with decreased density was found close to the anteroinferior edge of the body of the axis in the specimens from younger subjects. In contrast, a large area of trabecular bone with decreased density extending anteroinferiorly to superoposteriorly to the base of the dens was found in the specimens from older subjects. Based on these findings, we think that dens fracture classification systems and fixation techniques should be reconsidered.


Foot & Ankle International | 2001

Trimalleolar fracture with a double fragment of the posterior malleolus: a case report and modified operative approach to internal fixation.

Theofilos Karachalios; Nikolaos Roidis; Dimitrios Karoutis; Konstantinos Bargiotas; George Karachalios

Fractures of the medial and lateral malleoli are frequently associated with fractures of the posterior malleolus, comprising trimalleolar fractures. The posterior fragment may be posteromedial or posterolateral and its size determines the necessity for surgical or non-surgical treatment. The authors describe a case of trimalleolar fracture with double involvement of the posterior malleolus, both a posteromedial and posterolateral fragment. A modified transmalleolar operative approach for internal fixation is recommended when dealing with such complex trimalleolar fractures of the ankle.


Journal of orthopaedic surgery | 2009

The Influence of the Acromioclavicular Joint Degeneration on Supraspinatus Outlet Impingement and the Acromion Shape

Nikolaos Roidis; Soheil Motamed; Suketu Vaishnav; Edward Ebramzadeh; Theofilos Karachalios; John M. Itamura

Purpose. To assess the anatomic association of acromioclavicular joint degeneration to supraspinatus outlet impingement and the acromion shape. Methods. Sagittal oblique magnetic resonance images of 49 shoulders in 49 patients were reviewed. 29 of them (mean age, 59 years) underwent surgery for impingement with or without rotator cuff tear (group 1), whereas the 20 controls (mean age, 27 years) were treated for shoulder instability without rotator cuff disease or acromioclavicular joint derangement (group 2). The supraspinatus outlet and the acromion shape of the 2 groups were compared. Results. The difference in the mean supraspinatus outlet between groups 1 and 2 was 11% (514 vs 577 mm2, p=0.095) and between the subgroup (of group 1) with full thickness rotator cuff tears and group 2 was 17% (481 vs 577 mm2, p=0.036). Six of the acromions in group 1 were type III (hooked) compared to none in group 2. Conclusion. In severe acromioclavicular degeneration, distal clavicular excision is recommended, even in cases with an asymptomatic acromioclavicular joint, so as to prevent further osteophyte formation.

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John M. Itamura

University of Southern California

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Stamatios A. Papadakis

University of Southern California

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Suketu Vaishnav

University of Southern California

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Edward J. McPherson

University of Southern California

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K. Malizos

University of Thessaly

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K. Bargiotas

Athens State University

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Michael J. Patzakis

University of Southern California

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Paul Holtom

University of Southern California

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