Publications by Year: 2013

2013
Bobotas K, Lallos SN, Nikolaou VS, Kοrres DS, Efstathopoulos NE. Successful treatment of congenital pseudarthrosis of the tibia: still a challenge. Eur J Orthop Surg Traumatol. 2013;23 Suppl 2:S303-10.Abstract
The congenital pseudarthrosis of the tibia (CPT) is one of the most challenging problems in pediatric orthopedics. The primary treatment goals are outlined as osteosynthesis, stabilization of the ankle mortise by fibular stabilization and lower-limb-length equalization. Despite the fact that each of the aforementioned goals is difficult to be achieved regardless the surgical option, the main biological consideration is the same: pseudarthrosis resection, biological bone bridging of the defect by stable fixation and the correction of any angular deformity. The external fixation method is suggested as valuable treatment of CPT because it can address not only pseudarthrosis but also all complex deformities associated with this condition. However, treatment of CPT is impaired with complications due to the complex nature of the disease thus failure is common. The most common of these are refracture, growth disturbance, poor foot and ankle function with stiffness. Of these, refracture is the most common and serious complication after primary healing and might result in the reestablishment of pseudarthrosis. Therefore, an effective, safe and practical treatment method that minimizes the residual challenges after healing and accomplishes the multiple goals of treatment is needed. In this article, we report a patient with CPT treated successfully with external fixation. Level of evidence IV retrospective.
Nikolaou VS, Petit A, Zukor DJ, Papanastasiou C, Huk OL, Antoniou J. Presence of cobalt and chromium ions in the seminal fluid of young patients with metal-on-metal total hip arthroplasty. J Arthroplasty. 2013;28(1):161-7.Abstract
We aimed to investigate the effect of metal ions on the semen of males of child fathering age with metal-on-metal (MM) total hip arthroplasty (THA). Semen was collected form 11 patients with MM THA and 5 control of comparable age. Cobalt and chromium concentrations were measured in both the seminal plasma and in the blood of patients. Results showed that cobalt level was higher in the seminal plasma of MM THA patients (2.89 μg/L) compared to control patients (1.12 μg/L) (P = .011). The ejaculate volume, the sperm density, the total sperm count, the pH, and the percentage of cells with normal morphology were in the range of the World Health Organization criteria for fertile population.
Mohammad-Shahi MH, Nikolaou VS, Giannitsios D, Ouellet J, Jarzem PF. The effect of angular mismatch between vertebral endplate and vertebral body replacement endplate on implant subsidence. J Spinal Disord Tech. 2013;26(5):268-73.Abstract
STUDY DESIGN: Comparative biomechanical study. OBJECTIVE: To determine whether an angular mismatch between the vertebral body replacement (VBR) endplate and the simulated foam vertebral endplate leads to accelerated subsidence in a cyclic compression model of the VBR-vertebra interface. SUMMARY OF BACKGROUND DATA: One of the main complications of the VBR surgery is postoperative subsidence and collapse of the VBR implant into the adjacent vertebral bodies. Although numerous factors affecting intervertebral cage subsidence have been cited, few studies have proposed factors responsible for VBR cage subsidence. METHODS: Hardwood blocks at 0-30-degree angles and polyurethane foam blocs have been used as base for this experimental setting. One end of the Synex (Synthes) expandable cage was attached to a material testing machine. The endplate of the implant was placed at a similar spot on the block in such a manner that there was an exact match between the Synex endplate and the foam block at 0 degrees, subsequent angled blocks would tilt the foam endplates by the 10-, 20-, and 30-degree increments as needed. Cyclic axial loads were applied in 9 load-unload cycles. RESULTS: Five samples were tested at each mismatch angle (0, 10, 20, and 30 degrees), for a total of 20 trials. Implant subsidence significantly increased for each 10-degree increase in mismatch angle. This effect, however, did not follow a uniform trend at all angles. The curve appeared exponential at 0 degree of angular mismatch, became linear at 10-20 degrees of mismatch, and then demonstrated some ability to resist load at 30 degrees, leading to a plateau at the higher loads. CONCLUSIONS: Increasing mismatch angles are an important factor in leading to increased cage subsidence into polyurethane blocks. Consequently, the incidence of subsidence in the clinical setting could be reduced by paying careful attention to ensuring that both the prosthetic and bony endplates are well apposed at the end of surgery.
Nikolaou VS, Korres D, Lallos S, Mavrogenis A, Lazarettos I, Sourlas I, Efstathopoulos N. Cemented Müller straight stem total hip replacement: 18 year survival, clinical and radiological outcomes. World J Orthop. 2013;4(4):303-8.Abstract
AIM: To present the 18 year survival and the clinical and radiological outcomes of the Müller straight stem, cemented, total hip arthroplasty (THA). METHODS: Between 1989 and 2007, 176 primary total hip arthroplasties in 164 consecutive patients were performed in our institution by the senior author. All patients received a Müller cemented straight stem and a cemented polyethylene liner. The mean age of the patients was 62 years (45-78). The diagnosis was primary osteoarthritis in 151 hips, dysplasia of the hip in 12 and subcapital fracture of the femur in 13. Following discharge, serial follow-up consisted of clinical evaluation based on the Harris Hip Score and radiological assessment. The survival of the prosthesis using revision for any reason as an end-point was calculated by Kaplan-Meier analysis. RESULTS: Twenty-four (15%) patients died during the follow-up study, 6 (4%) patients were lost, while the remaining 134 patients (141 hips) were followed-up for a mean of 10 years (3-18 years). HSS score at the latest follow-up revealed that 84 hips (59.5%) had excellent results, 30 (22.2%) good, 11 (7.8%) fair and 9 (6.3%) poor. There were 3 acetabular revisions due to aseptic loosening. Six (4.2%) stems were diagnosed as having radiographic definitive loosening; however, only 1 was revised. 30% of the surviving stems showed no radiological changes of radiolucency, while 70% showed some changes. Survival of the prosthesis for any reason was 96% at 10 years and 81% at 18 years. CONCLUSION: The 18 year survival of the Müller straight stem, cemented THA is comparable to those of other successful cemented systems.
Hageman MGJS, Guitton TG, Ring D. How surgeons make decisions when the evidence is inconclusive. J Hand Surg Am. 2013;38(6):1202-8.Abstract
PURPOSE: To address the factors that surgeons use to decide between 2 options for treatment when the evidence is inconclusive. METHODS: We tested the null hypothesis that the factors surgeons use do not vary by training, demographics, and practice. A total of 337 surgeons rated the importance of 7 factors when deciding between treatment and following the natural history of the disease and 12 factors when deciding between 2 operative treatments using a 5-point Likert scale between "very important" and "very unimportant." RESULTS: According to the percentages of statements rated very important or somewhat important, the most popular factors influencing recommendations when evidence is inconclusive between treatment and following the natural course of the illness were "works in my hands," "familiarity with the treatment," and "what my mentor taught me." The most important factors when evidence shows no difference between 2 surgeries were "fewer complications," "quicker recovery," "burns fewer bridges," "works in my hands" and "familiarity with the procedure." Europeans rated "works in my hands" and "cheapest/most resourceful" of significantly greater importance and "what others are doing," "highest reimbursement," and "shorter procedure" of significantly lower importance than surgeons in the United States. Observers with fewer than 10 years in independent practice rated "what my mentor taught me," "what others are doing" and "highest reimbursement" of significantly lower importance compared to observers with 10 or more years in independent practice. CONCLUSIONS: Surgeons deciding between 2 treatment options, when the evidence is inconclusive, fall back to factors that relate to their perspective and reflect their culture and circumstances, more so than factors related to the patient's perspective, although this may be different for younger surgeons. CLINICAL RELEVANCE: Hand surgeons might benefit from consensus fallback preferences when evidence is inconclusive. It is possible that falling back to personal comfort makes us vulnerable to unhelpful commercial and societal influences.