Theodoros A. Xenakis

Accuracy of pedicle screw placement: a systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques.

IntroductionWith the advances and improvement of computer-assisted surgery devices, computer-guided pedicle screws insertion has been applied to the lumbar, thoracic and cervical spine. The purpose of the present study was to perform a systematic review of all available prospective evidence regarding pedicle screw insertion techniques in the thoracic and lumbar human spine. Materials and methodsWe considered all prospective in vivo clinical studies in the English literature that assessed the results of different pedicle screw placement techniques (free-hand technique, fluoroscopy guided, computed tomography (CT)-based navigation, fluoro-based navigation). MEDLINE, OVID, and Springer databases were used for the literature search covering the period from January 1950 until May 2010.Results26 prospective clinical studies were eventually included in the analysis. These studies included in total 1,105 patients in which 6,617 screws were inserted. In the studies using free-hand technique, the percentage of the screws fully contained in the pedicle ranged from 69 to 94%, with the aid of fluoroscopy from 28 to 85%, using CT navigation from 89 to 100% and using fluoroscopy-based navigation from 81 to 92%. The screws positioned with free-hand technique tended to perforate the cortex medially, whereas the screws placed with CT navigation guidance seemed to perforate more often laterally.ConclusionsIn conclusion, navigation does indeed exhibit higher accuracy and increased safety in pedicle screw placement than free-hand technique and use of fluoroscopy.

Assessment of curve progression in idiopathic scoliosis

Abstract In a 5-year prospective study on idiopathic scoliosis, an attempt was made to elucidate the natural history of the disease and to determine which factors contribute to curve progression. A total of 85,622 children were examined for scoliosis in a prospective school screening study carried out in northwestern and central Greece. Curve progression was studied in 839 of the 1,436 children with idiopathic scoliosis of at least 10° detected from the school screening program. Each child was followed clinically and roentgenographically for one to four follow-up visits for a mean of 3.2 years. Progression of the scoliotic curve was recorded in 14.7% of the children. Spontaneous improvement of at least 5° was observed in 27.4% of them, with 80 children (9.5%) demonstrating complete spontaneous resolution. Eighteen percent of the patients remained stable, while the remaining patients demonstrated nonsignificant changes of less than 5° in curve magnitude. A strong association was observed between the incidence of progression and the sex of the child, curve pattern, maturity, and to a lesser extent age and curve magnitude. More specifically, the following were associated with a high risk of curve progression: sex (girls); curve pattern (right thoracic and double curves in girls, and right lumbar curves in boys); maturity (girls before the onset of menses); age (time of pubertal growth spurt); and curve magnitude (≥ 30°). On the other hand, left thoracic curves showed a weak tendency for progression. In conclusion, the findings of the present study strongly suggest that only a small percentage of scoliotic curves will undergo progression. The pattern of the curve according to curve direction and sex of the child was found to be a key indicator of which curves will progress.

Nerve and vessel injuries during high tibial osteotomy combined with distal fibular osteotomy: a clinically relevant anatomic study.

Abstract Based on our clinical experience and an anatomical study, we examined the conditions under which injury to the popliteal artery, tibial nerve or peroneal nerve and its branches may occur during high tibial osteotomy. In 250 high tibial osteotomies performed in our department, we observed the following intraoperative complications. (1) The popliteal artery was severed in 1 patient and repaired by the same surgical team using a microsurgical technique. (2) A tibial nerve paresis also occurred in 1 patient. (3) In 3 patients, temporary palsy of the anterior tibialis muscle was documented. (4) In 4 other patients, palsy of the extensor hallucis longus occurred. To investigate the causes of these complications in the popliteal artery, tibial nerve and branches of the peroneal nerve, we dissected the neurovascular structures surrounding the area of the osteotomy in 10 cadaveric knees and performed a high tibial osteotomy in another 13 cadaveric knees. We concluded the following. (1) The popliteal artery and tibial nerve are protected, at the level of the osteotomy, behind the popliteus and tibialis posterior muscles. Damage can occur only by placing the Hohman retractor behind the muscles. The insertion of the muscles is very close to the periosteum and can be separated only with a scalpel. (2) The tibialis anterior muscle is innervated by a group of branches arising from the deep branch of the peroneal nerve. In two-thirds of the dissected knees, we found a main branch close to the periosteum, which can be damaged by dividing the muscle improperly or due to improper placement and pressure of the Hohman retractor. This may explain the partially reversible muscle palsy. (3) The extensor hallucis longus is also innervated by 2–3 thin branches, arising from the deep branch of the peroneal nerve, but in 25% of the specimens, only one large branch was found. This branch is placed under tension by manipulating the distal tibia forward. Thus, it may be damaged by the Hohman retractor during distal screw fixation, tensioned by hyperextension or directly injured during midshaft fibular osteotomy.

Diagnostic and treatment modalities in nonunions of the femoral shaft. A review

Nonunions of the femoral shaft represent a treatment challenge for the orthopaedic surgeon and a serious socioeconomic problem for the patient. Inadequate fracture stability, insufficient blood supply, bone loss or presence of infection are the main reasons for the development of a nonunion. Careful classification and exclusion of infection are crucial for the choice of the proper treatment alternative. Nail dynamization, primary intramedullary nailing or nail exchange, plate osteosynthesis and external fixation along with bone grafting, usage of bone substitutes and electrical stimulation can stimulate osseous union. A review of the aetiology, classification and treatment should prove helpful managing this serious complication.

Endoscopic Versus Open Carpal Tunnel Release

PURPOSE This study compared endoscopic carpal tunnel release with the conventional open technique with respect to short- and long-term improvements in functional and clinical outcomes. METHODS We assessed 72 outpatients diagnosed with carpal tunnel syndrome. Of these patients, 37 underwent the endoscopic method according to Chow and 35 were assigned to the open method. Improvement in symptoms, severity, and functionality were evaluated at 2 days, 1 week, 2 weeks, and 1 year postoperatively. Changes in clinical outcomes were evaluated at 1 year postoperatively. Complications were also assessed. RESULTS Both groups showed similar improvement in all but 1 outcome 1 year after the release; increase in grip strength was significantly higher in the endoscopic group. However, the endoscopic method showed a greater improvement in symptoms and functional status compared with the open method at 2 days, 1 week, and 2 weeks postoperatively. Separate analysis of the questions referring to pain showed that the delay in improvement in the open group was because of the persistence of pain for a longer period. Paresthesias and numbness decrease immediately after the operation with comparable rates for both groups. CONCLUSIONS Endoscopic carpal tunnel release provides a faster recovery to operated patients for the first 2 weeks, with faster relief of pain and faster improvement in functional abilities. Paresthesia and numbness subside in an identical manner with the 2 techniques. At 1 year postoperatively, both open and endoscopic techniques seem to be equivalently efficient.

Decompressive surgery for degenerative lumbar spinal stenosis: long-term results

We report the outcome of 50 patients with degenerative lumbar spinal stenosis who were treated surgically by spinal decompression between 1984 and 1995. Their mean age at the time of surgery was 59.9 (45–77) years and the mean follow-up was 11.6 (6.1–17.2) years. Five patients had a concomitant spinal fusion. The preoperative data were collected retrospectively from the patients’ charts. The follow-up data were obtained from a clinical examination and questionnaire including overall pain, ability to work, walking ability, use of analgesics and satisfaction with surgery. The outcome was rated as excellent in 23 patients, good in 13 patients, fair in 9 patients and poor in 5 patients. Patients with concomitant fusion had good to excellent results and were more satisfied, whereas patients with long-standing preoperative symptoms had poor to fair result and were less satisfied.RésuméNous rapportons le résultat de 50 malades avec une sténose lombaire dégénérative qui a été traité chirurgicalement par décompression vertébrale entre 1984 et 1995. L’âge moyen à la chirurgie était 59,9 (45–77) ans et le suivi moyen était 11,6 (6.1–17.2) années. Cinq malades avaient une fusion vertébrale concomitante. Les données préopératoires ont été rassemblées rétrospectivement. Les données du suivi ont été obtenues par un examen clinique et un questionnaire qui inclut les douleurs , la capacité de travailler, la capacité de marcher, l’usage d’analgésiques et la satisfaction de la chirurgie. Le résultat a été estimé comme excellent pour 23 malades, bon pour 13 malades, juste pour 9 et mauvais pour 5 malades. Les patients avec une fusion concomitante avaient des résultats bons ou excellents et étaient plus satisfaits alors que ceux avec symptômes préopératoires anciens avaient des résultats moyens ou mauvais et étaient moins satisfaits.

Osteoid osteoma in the differential diagnosis of persistent joint pain.

We report 20 cases (13 male and 7 female), mean age 21 years) of juxta-articular osteoid osteoma. The distribution of affected joints was as follows: hip joint (7 cases), knee joint (2 cases), ankle joint (2 cases); iliosacral joint (2 cases), lumbar spine (2 cases), carpus (2 cases), shoulder (1 case), second metacarpal (MCP; 1 case) and first metatarsal (MTP; 1 case). The duration between the onset of symptoms and diagnosis varied from 8 months to approximately 4 years. In juxta-articular osteoid osteoma, the clinical picture and the radiographic findings are often atypical, and this may lead to misdiagnosis and delayed definitive treatment. In young patients with persistent undiagnosed pain, the possibility of an osteoid osteoma should be considered. When the clinical picture is suggestive but radiological findings are negative, we must proceed to further investigation with bone scintigraphy and computed tomography. These examinations should be repeated 1 year after the onset of symptoms because initially negative findings may become positive at a later date. When the diagnosis of an osteoid osteoma is confirmed, surgical excision leads to complete relief of the symptoms.

Reliability and validity of the Hartofilakidis classification system of congenital hip disease in adults

The reliability and validity of the Hartofilakidis et al. classification system in adults with congenital hip disease (CHD) were examined. The radiographs of 102 adult patients (158 hips) with CHD were independently assessed by three senior surgeons. Interobserver variability was assessed by examining the agreement between the three raters while validity of the classification system was assessed by examining the agreement between the assessment by either one of the three raters and the intraoperative finding (reference standard). The interobserver agreement between the three observers was high ranging from 0.720 to 0.854 (substantial to excellent) while the agreement of the preoperative prediction with the intraoperative findings was 87.4% (K = 0.823, excellent agreement). The Hartofilakidis et al. classification system reliably predicts from preoperative pelvis radiographs the bone deficiencies encountered during the operation.RésuméNous avons voulu tester dans ce travail la fiabilité et la viabilité de la classification d’Hartofilakidis dans les séquelles des affections congénitales de la hanche. Les radios de 102 adultes (158 hanches) avec lésions congénitales ont été analysées, de façon indépendante par trois chirurgiens seniors avec validation inter observateur et intra observateur. Les résultats de cette analyse inter observateur sont hautement significatifs de 0.720 à 0.854 et les prévisions pré opératoires confirmées par les constatations per opératoires sont excellentes 87.4% (k = 0.823). La classification d’Hartofilakidis est un système parfaitement viable qui permet de prévoir un pré opératoire les lésions que l’on pourra constater en per opératoire.

Migration of the Trabecular Metal Monoblock Acetabular Cup System

Fifty-one primary total hip arthroplasties were performed using Trabecular Metal Monoblock Acetabular Cup System (Zimmer Inc, Warsaw, IN). In a 2-year prospective study, its behavior was closely monitored by clinical, radiologic, and component migration assessment by Ein-Bild-Röntgen-Analyse method. There were no complications. The mean Harris hip score was improved from 41 to 95. A polar gap at the postoperative radiograph was noted at 25% of the arthroplasties, most of which subsequently filled with bone within 6 months. The mean total absolute migration was 0.67 mm. The implant showed excellent early clinical and radiographic behavior. The 2-year migration rate study, as index of long-term survival and success, showed very good early implant stability and, in all cases except one, superior to the available studies for similar design acetabular cups.

Low grade fibromyxoid sarcoma: a case report and review of the literature

Low grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma with a high metastasizing potential and sometimes long interval between tumour presentation and metastasis. We present the case of a 50-year-old male who developed a large mass in the posterior aspect of his lower left thigh. The tumor was excised with preservation of the neurovascular structures surrounded by the mass. The tumour measured 11 × 10 × 9 cm and on pathology evaluation was diagnosed as LGFMS. Due to the relative rarity of LGFMS, there is no dedicated protocol regarding follow-up recommendations. In order to early diagnose possible metastasis it is important to inform the patients about the longstanding metastatic potential of the disease.