Periprosthetic joint infection from Mycobacterium Tuberculosis in Togo, Africa.

Mycobacterium Tuberculosis infections are moderately frequent in developing countries. Because of migratory flows, these diseases will always have an increasing prevalence even in those countries that do not usually present these types of cases. Extra-pulmonary tuberculosis often affects the musculoskeletal system. The sites most involved are the spine (Pott's disease) and the large joints, especially hips and knees. We describe a patient with tuberculosis of the hip, who underwent total hip arthroplasty.

Histological assessment of new bone formation with biomimetic scaffold in posterolateral lumbar spine fusion.

Spinal fusion procedures often require the use of bone grafts (autograft or allograft) to help bone healing and to increase stability. However, the application of autografts is frequently limited by donor site morbidity. In recent years, different synthetic bone substitutes have been introduced in the clinical practice to overcome these limitations. The purpose of this paper is to report a case where a biomimetic, synthetic and osteoconductive bone graft substitute was successfully implanted in a patient during lumbar spine arthrodesis. The case of a 58-year-old female subjected to lumbar spine arthrodesis with bone augmentation is described. The bone graft substitute RegenOss® (Finceramica, Faenza, Italy) was implanted during spinal arthrodesis. The successful bone integration was evaluated by X-rays. After 11 months, the patient underwent a second surgery due to spine imbalance; the debris of the bone graft was therefore collected and analyzed by macroscopic evaluation and by histology. The bone substitute was successfully implanted during a spinal arthrodesis procedure. Histologic evaluation of the removed bone graft debris showed the complete resorption of the implant and the formation of new bone, which was well integrated with the host bone. This bone substitute may represent a safe and effective alternative to autologous bone grafts, avoiding adverse events related to donor-site morbidity.

Clinical anatomy of the meniscus in animal models: pros and cons.

Nowadays, despite the possibility to use in vitro or computer models in research, animal models are still essential. Different animal models are available for meniscal repair investigation. Although a unique perfect model for the structure of the human's knee does not exist, the choice of the proper animal model is crucial for a correct research. The principal animal models in the meniscal repair are sheep, goats, pigs and dogs. Each of these has pros and cons for their utilization. Analysing each pro and con is essential for optimizing the choice of the animal model, which depends on the experimental question, avoiding unnecessary waste of resources and minimizing the animal suffering, according to the Russell and Burch's three "Rs" principles (Reduce, Refine and Recycle). In this concise review, we resume the meniscus anatomical features of the main large animals, to help choose the most suitable animal model for subsequent studies on meniscal repair.

Total hip arthroplasty for osteonecrosis of the femoral head in sickle cell disease: a case series from our African experience.

Sickle cell disease causes osteonecrosis (20% to 50% of patients) and collapse of the femoral head that result in secondary osteoarthritis. Total hip arthroplasty (THA) is a valid alternative for these patients. We define the difficulties that can be encountered when undertaking THA in sickle cell disease patients and give advice on how to deal with these technically demanding procedures. We undertook total hip arthroplasty procedures on 12 patients (4 females and 8 males) with osteonecrosis of the femoral head. Two bilateral prostheses were performed. We had only one type of stem, only one type of acetabular cup and only 28 mm cobalt chrome heads. The procedures were performed through either an anterior or a direct lateral approach. The average size of the Cup was 46 (Versafit, Medacta), the average size of the femoral stem was 0 (Amistem, Medacta), the most used size of the modular head was a S. Standard stem that was used in nine patients, while three patients received a lateralizing stem. Three patients had periprosthetic fracture, treated by cerclage. Total hip replacement is an excellent alternative for patients with osteonecrosis from sickle cell disease. The preparation of the acetabulum and the femur is difficult and requires attention, time and appropriate equipment.

Combined circular external fixation and flexible intramedullary nailing for pediatric bilateral open tibia fractures in blast injury.

Management of blast injuries with open fractures and extensive soft tissue damage in pediatric patients is a challenging task even in experienced hands. This article reports the case of an 8-year-old boy with bilateral open tibia fractures and soft tissue loss due to the accidental explosion of a skyrocket. After the emergency procedures with lavage, debridement and temporary bone stabilization, we performed the definitive reconstruction surgery using a combined circular external fixation and flexible intramedullary nailing technique on both legs. This technique allowed easy access to the wounds for plastic surgery procedures and early bilateral weight bearing. All implants were removed within 6 months, the fractures healed with good axial alignment and the patient returned to his preinjury activities one year after the trauma. In this case, the combined use of circular external fixation and flexible intramedullary nailing ensured optimal fractures stabilization, minimizing the damage to the soft tissues and the obstruction for plastic surgeons. We believe that this technique should be considered in pediatric patients with open fractures of the lower limbs and extensive soft tissue injuries.

Histological assessment of new bone formation with biomimetic scaffold in the presence of bone loss in trauma surgery.

Open reduction and internal fixation (ORIF) surgery may require the use of bone grafts (usually allogeneic). In the context of traumatology surgeries, the use of autologous grafts is almost never used and allogeneic grafts are not always available. In recent years, bone substitutes have been introduced in clinical practice to overcome these limitations. The purpose of this paper is to report two cases in which the use of a bone substitute was used to overcome the bone loss during surgeries of ORIF. Two patients, one with a tibial plateau fracture (Schatzker 6) and one with a proximal humerus fracture (Neer 4), underwent ORIF surgery. In both cases, due to a loss of bone stock, a synthetic bone substitute (OrthOss®) was used. One year after surgery, the complete osseointegration of the synthetic bone substitute was seen, both radiologically and histologically. This bone substitute may represent a safe and effective alternative to autologous bone grafts, avoiding adverse events related to donor-site morbidity.

Animal models for cartilage repair.

Cartilage lesions still represent an unsolved problem: despite the efforts of the basic and translational research, the regeneration of this tissue is far from being reached (1-3). Articular cartilage lesions can be divided in two main groups: superficial or partial defects and full-thickness defects (4, 5). Partial lesions are not able to self-heal because multipotent cells from the bone marrow cannot reach the area leading to a progressive degeneration of the tissue (6). Conversely, full-thickness injuries possess greater chances to heal because subchondral bone involvement allows for the migration of mesenchymal cells, which fill the damaged area (7, 8). However, healing occurs through the formation of a fibrocartilaginous tissue, which has different biomechanical and biological properties (9). Native hyaline cartilage has indeed specific biomechanical properties, which confer resistance to compressive and shear stresses; the reparative fibrocartilaginous tissue lacks these abilities, therefore, the surrounding healthy cartilage progressively degenerates. In the past years, several therapeutic strategies have been developed to restore the damaged cartilage, bone marrow stimulation (chondroabrasion, drilling, micro- or nano-fractures) and more recently, tissue engineering approaches (10-14). Some of these latter procedures have already been applied in clinical practice such as matrix-induced autologous chondrocyte implantation (MACI) (15) or osteochondral scaffold implantation (16). Generally, tissue engineering approaches are based on the combination of three main elements: cells (i.e. primary chondrocytes or multipotent mesenchymal cells), biocompatible scaffolds (i.e. polymers, composites, ceramics) and signaling molecules (i.e. growth factors). Moreover, several culture conditions (i.e. static or dynamic cultures) and biomechanical stimuli can be applied during the in vitro culture to promote tissue maturation (17-19). However, an in vivo culture is mandatory to validate a new engineered construct as the in vitro phase lacks the essential in vivo environmental stimuli and because the in vivo culture allows for the testing of the biocompatibility and safety of a new material (18, 19). Moreover, preclinical animal models are crucial to understand the molecular mechanisms of cartilage lesions favoring the development of new regenerative strategies (20, 21). in vivo studies on animal models should focus on the analysis of the cellular component, analyzing the maintenance of the cellular phenotype and the tumorigenicity; on the evaluation of the biocompatibility, toxicity and degradation of the biomaterial and on the assessment of the engineered construct. In this manuscript, we will review the most common preclinical animal models, which are used to understand cartilage biology and therefore to develop new tissue engineering strategies. We will focus on both small and large animal models highlighting their peculiarities, advantages and drawbacks.

Comparison of three novel biphasic scaffolds for one-stage treatment of osteochondral defects in a sheep model.

In the last years, several tissue engineering techniques have been applied to develop different kinds of osteochondral substitutes to overcome the scarce reparative properties of this tissue. The aim of this study was to generate and compare three biphasic scaffolds in an osteochondral lesion in a large-animal model. A critical osteochondral defect was generated in the medial femoral condyle of 18 skeletally mature sheep. Three defects were left untreated, the remaining lesions were divided into three groups: 5 lesions were treated with a biphasic scaffold made of collagen type I and small cylinders of Magnesium Hydroxyapatite; 5 lesions were treated with a biphasic substituted formed by collagen type I and Wollastonite, 5 lesions were treated with a scaffold made of collagen type I and small cylinders of Wollastonite/Hydroxyapatite. Animals were sacrificed after 3 months and samples were analyzed by CT and MRI, macroscopic evaluation and histology. Our study demonstrated that one of these novel biphasic scaffolds possesses the potential for being applied for one-stage procedures for osteochondral defects.

Microsurgical excision without fusion as a safe option for resection of synovial cyst of the lumbar spine: long-term follow-up in mono-institutional experience.

Spinal synovial cysts are cystic dilatations of the synovial membrane that may arise at all levels of the spine. We describe our experience, paying attention to diagnosis, surgical treatment, and long-term follow-up. Between 1995 and 2007, 18 patients were surgically treated. Of these, three patients were excluded from the study because they presented spinal instability at pre-operative assessment. All patients were evaluated pre-operatively with CT, MRI, and dynamic X-rays, and underwent surgery for removal of the cyst by hemilaminectomy and partial arthrectomy. All patients were evaluated with early MRI and had a minimum 2-year follow-up by dynamic X-rays. None of the patients required instrumented fusion due to the absence of radiological signs of instability on the pre-operative dynamic tests. In all patients, there was an immediate resolution of the symptoms, with evidence of complete removal of the cysts on post-operative MRI. At 2-year follow-up, all patients underwent dynamic X-rays and responded to a questionnaire for evaluation of outcome. None of them showed signs of relapse. The gold standard for treatment is surgery, even though other conservative treatment regimens have been proposed. Correct surgical strategy relies on pre-operative assessment of biomechanical stability for deciding whether patients need instrumented fusion during cyst removal. Patients with no instability signs are suitable for hemilaminectomy with partial arthrectomy, preserving 2/3 of the medial portion of the articular facet, because this represents a valid option of treatment with a low risk of complications and a low rate of relapse.

The use of platelet gel in postero-lateral fusion: preliminary results in a series of 14 cases.

Over the last few years, some hemocomponents have been used advantageously in clinical neurosurgical practice, not systemically via transfusion but topically as a sealant (fibrin glue). This has diverted the attention of many authors to the role of platelets in the healing process. The combination of hyper-concentrated platelets and fibrin glue (fibrinogen, XIII factor, fibronectin) with activated thrombin produces a platelet gel that can be easily applied to "difficult" wounds. This topical use of hemocomponents has gained an important role in regenerative medicine. The authors have considered the possibility of using a preparation with a high autologous platelet concentration applied in addition to autologous bone during vertebral postero-lateral fusion. The aim of the procedure is to induce a higher rate of vertebral fusion. Between November 2007 and November 2008, 14 patients (9 men and 5 women, mean age 58.9) underwent laminectomy, vertebral stabilization and postero-lateral fusion. The number of vertebral levels involved in stabilization was: 1 in 2 patients, 2 in 5 patients, 3 in 5 patients, 4 in 1 patient and 5 in 1 patient. Platelet gel was obtained by taking 16 ml of peripheral venous blood from the patient. For this procedure two patented test tubes were used for each patient, with a capacity of 8 m each. These make up the REGEN-THT(®) (Thrombocyte Harvesting Tube) system that makes it possible to obtain 8 ml of autologous platelet gel in 40-45 min. The addition of Ca gluconate and ethanol at 95% makes it possible to obtain a preparation of plasma rich in platelets and activated thrombin with a platelet concentration five times superior to the haematic one. The platelet gel is combined with fragments of autologous bone and synthetic bone during surgical operation. To allow a comparative assessment of the degree of fusion achieved with and without application of the platelet preparation in each patient, it was arbitrarily decided to use it in only one half of the operative field. All patients underwent serial CT scans 3 and 6 months after surgery as well as plain X-rays to evaluate bone fusion. The reconstructed CT images, especially in sagittal and axial planes, permitted an evaluation of the degree of vertebral fusion and "bone growth". The fusion rate was calculated measuring the increment of bone density on CT images, by means of an evaluation of the ROI (HU) in the newly formed bone, and comparing bone density within the bone callus formed by autologous and synthetic bone alone in the one to which the platelet preparation had been added. A good rate of fusion was observed in all patients. Furthermore, a comparative analysis of ROI at 3 and 6 months after surgery demonstrated a high increase in the fusion rate during the first 3 months after surgery. After 6 months the differences in ROI between the two sides had balanced out. However, at 6-month follow-up examination, bone density in the half of the surgical field in which platelet gel had been added to autologous-heterologous bone was higher in comparison to the contralateral one. Bony neoformation after posterior-lateral arthrodesis is well-evident 3 months after surgery and usually continues gradually for the following 18-24 months. The autologous platelet preparation used seems to accelerate bony deposition and to promote tissue healing, increasing bone density at the level of posterior-lateral arthrodesis. Moreover, this preparation has low production costs and is easy to apply.

Spontaneous reduction of intracranial arachnoid cysts: a complete review.

The aetiopathology, clinical features and treatment of arachnoid cysts (AC) are still extremely controversial topics. The posterior fossa is the second most common site of these lesions, since they are often detected in the cerebellar or cerebellar-cistern region. Despite this, almost all the cases of non-surgical reduction of an AC reported in literature concern cysts of the middle fossa, whereas only two cases of spontaneous reduction of a posterior fossa AC has been described in literature. A complete review of the literature regarding this topic has been collected and discussed. The authors present a case of spontaneous reduction of an arachnoid cyst situated along the midline of the posterior cranial fossa with regression of all neurological symptoms. This 43-year-old man presented increasing nuchal headache with vomiting and nausea, simulating subarachnoid haemorrhage. CT and MRI documented an arachnoid cyst along the midline of the posterior fossa compressing the mesencephalon. The patient did not present any family history of this pathology nor had suffered head trauma. The patient was only given analgesics to relieve painful symptoms. After 30 days, spontaneous resolution of all the neurological symptoms took place. A 2 months, MRI control documented marked reduction of the cyst without any evident brain compression. The feasibility of a wait and see policy in such cases is discussed.

Hemangioblastoma of the filum terminale. Case report and review of the literature.

Hemangioblastomas of the filum terminale are particularly rare tumors. The authors present the case of a 62-year-old woman with a 6 month history of low-back-pain, who underwent surgery for the removal of an hemangioblastoma affecting the cauda at L2-L3 level. This highly vascularized tumour is tightly adherent to the filum terminale and hence is a very challenging pathology to remove. Histologically it consisted in vascular structures interposed to a network of capillary-like vessels, surrounded by stromal cells. MRI, angiography with pre-surgical embolization, and radical surgery represent the focal points in the diagnosis and treatment of these tumours. The most relevant literature has been carefully reviewed.

Spinal subarachnoid hematomas: our experience and literature review.

STUDY DESIGN: Spinal subarachnoid hematomas are unusual and difficult to diagnose and the outcome of treatment is influenced by the lesions that frequently accompany them. OBJECTIVES: To clarify the neuroradiological diagnostic aspects of spinal subarachnoid hematoma as well as the results of treatment. BACKGROUND: Only recently has subarachnoid hematoma been clearly distinguished from more common subarachnoid hemorrhage and its characteristics have still not been dealt with in detail. METHODS: A total of 69 cases (3 personal case, 66 published cases) were revised in terms of etiology, diagnostic imaging and the results of both surgical and conservative treatment. RESULTS: The most common causes of spinal subarachnoid hematoma are coagulopathies (either pharmacologically-induced or resulting from systemic diseases) (40.5%), lumbar puncture for diagnostic or anesthesiological purposes (44.9%) and traumatic injuries (15.9%): these factors may be present singly or variously combined. They may be spontaneous (17.3%) or, in rare cases, associated with aortic coarctation or degenerative vascular diseases. Overall mortality is 25.7%. In the 50 cases in whom long-term follow-up was possible, the outcome of treatment, which is almost exclusively always surgical, was good in 93.5% of 31 patients in whom neurological status on admission was satisfactory and in 15.8% of 19 cases with severe neurological deficits. CONCLUSIONS: MRI and CT are not usually diagnostic because they are not able to differentiate between a subarachnoid lesion and a subdural one. However, diagnosis may be possible when these investigations detect the CSF or the contrast medium surrounding the hematoma. Although the risks of producing spinal subarachnoid hematoma as a result of LP are remote, this is, in fact, the primary cause in patients with coagulopathies. The results of treatment depend on the patient's initial neurological condition, the severity of any concomitant pathologies, the position of the hematoma and the eventual association of a subdural hematoma.

Diagnosis and follow-up of minor cervical trauma.

In order to evaluate sensitivity, specificity and accuracy of radiographic findings, 1347 patients with minor cervical injury underwent clinical, orthopaedic, neurosurgical examination, and were classified as monosymptomatic (only cervical pain) or polysymptomatic (cervical pain plus additional symptoms). X-rays were taken in anteroposterior, lateral and open-mouth views; additional views if necessary. X-ray outcome was normal in 69.8% of monosymptomatic patients and there were no fractures. In 45.1% of polysymptomatic patients, outcome was normal, but there were seven fractures. Computed tomography/magnetic resonance (CT/MR) was performed in patients with documented injury and/or strong persistent symptoms. X-ray follow-up at 4-6 weeks included flexion-extension examination. Elevated statistical radiographic values were reached. All patients with minor cervical trauma should undergo clinical, neurosurgical and three-view radiographic follow-up. A simplified algorithm could lead to substantial savings and decrease patients' exposure to radiation.

The results of the surgical and conservative treatment of non-neurologic comminuted thoracolumbar fractures.

A retrospective radiologic study of 40 non-neurologic thoracolumbar fractures allowed for the evaluation of the long-term results of surgical and conservative treatment in terms of correction of the post-traumatic deformity. The Magerl classification and the McCormack scale were used to select compressive type fractures (type A), and fractures characterized by comminution of the vertebral body without involvement of the posterior elements. Instability related to comminution and to considerable diastasis of the fragments is at the basis of failure of conservative (plaster brace) and surgical (short posterior fixation and posterolateral fusion) treatments. Severe type A fractures treated conservatively have, in fact, at follow-up shown significant residual deformity, while failure of the instrumentation or loss of correction in 40% of cases treated surgically has been revealed.

Nontraumatic acute spinal subdural hematoma: report of five cases and review of the literature.

Acute subdural spinal hematoma occurs rarely; however, when it does occur, it may have disastrous consequences. The authors assessed the outcome of surgery for this lesion in relation to causative factors and diagnostic imaging (computerized tomography [CT], CT myelography), as well as eventual preservation of the subarachnoid space. The authors reviewed 106 cases of nontraumatic acute subdural spinal hematoma (101 published cases and five of their own) in terms of cause, diagnosis, treatment, and long-term outcome. Fifty-one patients (49%) were men and 55 (51%) were women. In 70% of patients the spinal segment involved was in the lumbar or thoracolumbar spine. In 57 cases (54%) there was a defect in the hemostatic mechanism. Spinal puncture was performed in 50 patients (47%). Late surgical treatment was performed in 59 cases (56%): outcome was good in 25 cases (42%) (in 20 of these patients preoperative neurological evaluation had shown mild deficits or paraparesis, and three patients had presented with subarachnoid hemorrhage [SAH]). The outcome was poor in 34 cases (58%; 23 patients with paraplegia and 11 with SAH). The formation of nontraumatic acute spinal subdural hematomas may result from coagulation abnormalities and iatrogenic causes such as spinal puncture. Their effect on the spinal cord and/or nerve roots may be limited to a mere compressive mechanism when the subarachnoid space is preserved and the hematoma is confined between the dura and the arachnoid. It seems likely that the theory regarding the opening of the dural compartment, verified at the cerebral level, is applicable to the spinal level too. Early surgical treatment is always indicated when the patient's neurological status progressively deteriorates. The best results can be obtained in patients who do not experience SAH. In a few selected patients in whom neurological impairment is minimal, conservative treatment is possible.

Meningiomas of the tuberculum sellae. Our experience in 69 cases surgically treated between 1973 and 1993.

BACKGROUND: Meningiomas of the tuberculum sellae are lesions with well-defined characteristics in terms of both site of origin and clinical evolution which require differential diagnosis with lesions of the supra- and para-sellar region. The aim of this study is to point out the importance of the size of the lesion and early identification of symptoms for prompt diagnosis, crucially important for evaluating the reversibility of functional damage, especially of the optic nerves. METHODS: Between 1953 and 1993, 110 cases of tuberculum sellae meningioma were operated at the Neurosurgical Institute, Department of Neurosciences, of Rome "La Sapienza" University; only 69 cases of these cases were operated on after 1973, the year in which microsurgical techniques were introduced into routine surgical practice. Tumor diameter ranged from 3 to 9 cm. Most of the patients presented severe visual loss. RESULTS: Removal was total in 63 cases (91.3%), sub-total in 6 (8.7%). Besides the surgeons firsthand impression, the grade of removal was evaluated by early CT and/or MRI (24-36 hours after surgery). A minimum follow-up of 3 years was taken into consideration for assessment of late functional results. Five patients died in the postoperative period (7.2%). CONCLUSIONS: This study clearly demonstrated that a tumor diameter greater than 4 cm is a critical factor for visual function. The size of the lesion was also found to be extremely important, in that it influences the amount of tumor resection possible. Therefore, in our opinion, alternative types of treatment such as radiosurgery should be confined to the tumor residue.

Surgical treatment of penetrating orbito-cranial injuries. Case report.

Penetrating orbital injuries are not frequent but neither are they rare. The various diagnostic and therapeutic problems are related to the nature of the penetrating object, its velocity, shape and size as well as the possibility that it may be partially or wholly retained within the orbit. The authors present another case with unusual characteristics and discuss the strategies available for the best possible treatment of this traumatic pathology in the light of the published data. The patient in this case was a young man involved in a road accident who presented orbito-cerebral penetration caused by a metal rod with a protective plastic cap. Following the accident, the plastic cap (2.5x2 cm) was partially retained in the orbit. At initial clinical examination, damage appeared to be exclusively ophthalmological. Subsequent CT scan demonstrated the degree of intracerebral involvement. The damaged cerebral tissue was removed together with bone fragments via a bifrontal craniotomy, the foreign body was extracted and the dura repaired. Postoperative recovery was normal and there were no neuro-ophthalmological deficits at long-term clinical assessment. Orbito-cranial penetration, which is generally associated with violent injuries caused by high-velocity missiles, may not be suspected in traumas produced by low-velocity objects. Diagnostic orientation largely depends on precise knowledge of the traumatic event and the object responsible. When penetration is suspected and/or the object responsible is inadequately identified, a CT scan is indicated. The type of procedure to adopt for extraction, depends on the size and nature of the retained object. Although the possibility of non-surgical extraction has been described, surgical removal is the safest form of treatment in cases with extensive laceration and brain contusion.

Acute posttraumatic subdural hematomas: "intradural" computed tomographic appearance as a favorable prognostic factor.

OBJECTIVE: Posttraumatic acute subdural hematoma carries a high postoperative mortality rate. Preservation of subarachnoid spaces in preoperative computed tomographic (CT) scans may be interpreted as a favorable prognostic factor. METHODS: Thirty-one cases of posttraumatic acute subdural hematoma operated on consecutively, with an interval from trauma to surgery of less than 4 hours and a Glasgow Coma Scale score of less than 8, were reviewed. The immediate and long-term results were evaluated with reference to preoperative CT images, distinguishing cases with preserved subarachnoid spaces from the others. RESULTS: In 5 of the 31 cases, preoperative CT scans showed intact subarachnoid spaces and the absence of blood in the cerebrospinal fluid. These cases presented a much better postoperative course than did the others. CONCLUSION: The presence of intact subarachnoid spaces in CT scans for patients with acute subdural hematomas may be interpreted as an extremely favorable prognostic factor; this may be attributed to the protective effect of the integral visceral membrane of the hematoma, which prevents the diffusion of neurotoxic and vasoactive substances into the subarachnoid spaces. This group of hematomas was classified as "intradural," with reference to the concept of the "subdural compartment" described in studies conducted using an electron microscope.