It has been proposed that intervertebral disc degeneration might be caused by low-grade infection. The purpose of the present study was to assess the incidence of herpes viruses in intervertebral disc specimens from patients with lumbar disc herniation. A polymerase chain reaction based assay was applied to screen for the DNA of eight different herpes viruses in 16 patients and two controls. DNA of at least one herpes virus was detected in 13 specimens (81.25%). Herpes Simplex Virus type-1 (HSV-1) was the most frequently detected virus (56.25%), followed by Cytomegalovirus (CMV) (37.5%). In two patients, co-infection by both HSV-1 and CMV was detected. All samples, including the control specimens, were negative for Herpes Simplex Virus type-2, Varicella Zoster Virus, Epstein Barr Virus, Human Herpes Viruses 6, 7 and 8. The absence of an acute infection was confirmed both at the serological and mRNA level. To our knowledge this is the first unequivocal evidence of the presence of herpes virus DNA in intervertebral disc specimens of patients with lumbar disc herniation suggesting the potential role of herpes viruses as a contributing factor to the pathogenesis of degenerative disc disease.
To determine the gross structural alterations of the nailed bone (femur or tibia) after the removal of an intramedullary nail (IMN). Eighteen patients (14 femoral and 4 tibia nail) underwent an IMN removal from their femur or tibia. Every patient had a spiral computed tomography scan and a plain X-ray study, immediately after the nail removal and also at their latest follow-up (24–30 months). The 4 patients with a tibia nail were additionally examined using a peripheral quantitative computed tomography study at their latest follow-up. All patients were asymptomatic. An intramedullary shell of compact bone was demonstrated around the nail track. This new bone was apparent on plain radiographs in all of the patients. Peripheral quantitative computed tomography study revealed that the density of the bony ring was similar to that of subcortical bone. The histologic examination of the intra-medullary shell of one of our patients suggested that the bony ring was made of cortical bone. Intramedullary nailing may enhance new cortical bone formation within the bone marrow cavity. This “cortical bone” still exists more than 2 years after implant removal. Nail insertion also causes thickening of the normal cortex at the sites of nail–cortex contact where loads are transferred from the nail to the cortex. This new finding could probably lead the research of intramedullary nailing biomechanics toward new directions as to understand the body’s reaction to IMNs.
The evaluation of two methods for the placement of the tibial component of total knee arthroplasties in obese patients Between December 2004 and October 2008 we studied 38 obese patients who underwent cemented total knee arthroplasty (using the rotating platform tibial tray) due to medial compartment osteoarthritis and consequent varus deformity. All patients had a body mass index (BMI)>
40. Functional outcome was assessed using the Knee Society Score (KSS). The study was based on the comparison between extramedullary (group A) and intramedullary (group B) instrumentation systems for the placement of the tibial prosthesis. The main endpoint was the immediate post-operative knee joint alignment. There were 10 male and 28 female patients. The average follow-up period was 13.8 months (minimum follow-up of 6 months). There were 22 patients in group A whereas 16 patients comprised group B. In 5 of the 22 patients in group A there was an average varus malalignment of 40 and a mean KSS of 71.5 at the time of the latest follow-up visit. In the rest of patients of both groups there was a valgus alignment between 0 and 70 and a mean KSS of 86.4 respectively Our experience suggests that the intramedullary instrumentation technique for the placement of the tibial component offers a more favourable post-operative alignment as well as better functional outcome in obese patients.
The timing of performing knee arthroplasties in bilateral osteoarthritic knees remains controversial. Our aim was to compare one-stage with two-stage bilateral knee arthroplasties (TKA). Between November 2004 and April 2008, 128 patients (72 female and 56 male) underwent one-stage bilateral TKAs. Another group of 115 patients that underwent two-stage procedures during the same period formed the control group. All patients received the same type of anaesthesia. Study parameters included age, weight, medical co-morbidities, length of hospital stay, blood loss, post-operative complications and functional outcome. There were no significant differences between the two groups. Co-morbidities and functional outcome based on the Knee Society Score were similar in both groups. In the one-stage group the length of hospital stay and blood losses were higher than the two-stage group; however less than double compared to the two-stage group. The early post-operative complications were higher but not statistically significant in the one-stage group. Despite the fact that the early post-operative complications are slightly higher in the one-stage group, this particular method is an effective way of dealing with bilaterally osteoarthritic knees. It offers excellent functional outcome at a reduced cost
The evaluation of early results of combined percutaneous pedicle screw fixation and kyphoplasty for the management of thoraco-lumbar burst fractures Between October 2008 and April 2009, 9 patients with thoracolumbar burst fractures underwent percutaneous short-segment pedicle screw fixation and augmentation kyphoplasty with calcium phosphate cement. All patients were selected according to the type of fracture (unstable type A3 fractures based on the Magerl classification) the absence of neurological signs and an intact posterior longitudinal ligament on the pre-operative MRI scan. Patient demographics, co-morbidities and complications were recorded. The main endpoints included Cobb angle correction, vertebral body height restoration and the length of hospital stay. There were 3 male and 6 female patients with an average age of 43.6 years. The average follow-up was 2.4 months. The mean kyphotic angulation improved from 18.40 pre-operatively to 6, 80 post-operatively. The loss of vertebral body height improved from a mean of 38.7 % pre-operatively to 12.1 % post-operatively. The average duration of surgery was 40 minutes with insignificant blood loss. There were no post-operative complications. The average length of hospital stay was 3.2 days. The combination of percutaneous short-segment pedicle screw fixation supplemented by balloon kypho-plasty for the management of thoracolumbar burst fractures with no neurological deficit offers correction of the normal thoracolumbar anatomy as well as augmentation of the anterior load-bearing column, using a minimally invasive technique. The early results are promising
The evaluation of results following posterior decompression and fusion for the management of cervical spondylotic myelopathy Between July 2006 and May 2008, 68 patients with cervical myelopathy underwent posterior decompression with laminectomies and pedicle screw fixation of the cervical spine. All patients were selected based on the presence of multi-level degenerative disease and the correction of cervical lordosis on the pre-operative dynamic radiographs. Patient demographics, co-morbidities and post-operative complications were recorded and analysed. Functional outcome was assessed by using the Japanese Orthopaedic Association (JOA) score. There were 37 male and 31 female patients with an average age 67.4 years. The average follow up period was 18 months. The mean pre-operative JOA score was 8.7, whereas the mean post-operative score was 12.1 on the latest follow-up visit. 9 patients had unsatisfactory clinical results and consequently underwent anterior procedures with significant improvement. Complications included 1 epidural haematoma, 2 superficial infections and 4 cases of myofascial pain. In three cases there was mild dysfunction of the C5 nerve root which resolved spontaneously with conservative measures. In the present series of patients posterior decompression with laminectomies is an effective method for the management of cervical spondylotic myelopathy.
The circulatory effects of multilevel balloon kyphoplasty (BK) are not adequately addressed, neither the effectiveness of egg shell cementoplasty in preventing anticipated cement leakage in difficult cases. The purpose of this study was to evaluate
the effect of multilevel BK to blood pressure and arterial blood gasses; the incidence of methylmethacrylate cement leakage using routine postoperative computer tomography scan and the effectiveness of egg shell cementoplasty to prevent cement leaks.
Vertebral haemangiomas are usually asymptomatic and discovered fortuitously during imaging. A small proportion may develop variable degrees of pain and neurological deficit. We prospectively studied six patients who underwent eight surgical procedures on 11 vertebral bodies. There were 11 balloon kyphoplasties, six lumbar and five thoracic. The mean follow-up was 22.3 months (12 to 36). The indications for operation were pain in four patients, severe back pain with Frankel grade C paraplegia from cord compression caused by soft-tissue extension from a thoracic vertebral haemangioma in one patient, and acute bleeding causing Frankel grade B paraplegia from an asymptomatic vascular haemangioma in one patient. In four patients the exhibited aggressive vascular features, and two showed lipomatous, non-aggressive, characteristics. One patient who underwent a unilateral balloon kyphoplasty developed a recurrence of symptoms from the non-treated side of the vertebral body which was managed by a further similar procedure. Balloon kyphoplasty was carried out successfully and safely in all patients; four became asymptomatic and two showed considerable improvement. Neurological recovery occurred in all cases but bleeding was greater than normal. To avoid recurrence, complete obliteration of the lesion with bone cement is indicated. For acute bleeding balloon kyphoplasty should be combined with emergency decompressive laminectomy. For intraspinal extension with serious neurological deficit, a combination of balloon kyphoplasty with intralesional alcohol injection is effective.
The overall fusion success rate in our series was 90%, while pseudoarthrosis occurred in 5 patients (10%), with screw breakage in 1 patient (2%). Two of these patients had bone graft supplementation and in other 2 patients was done anterior fusion.