Nikolaos Efstathopoulos

The anatomy of the ACL and its importance in ACL reconstruction.

The anterior cruciate ligament (ACL) anatomy is very significant if a reconstruction is attempted after its rupture. An anatomic study should have to address, its biomechanical properties, its kinematics, its position and anatomic correlation and its functional properties. In this review, an attempt is made to summarize the most recent and authoritative tendencies as far as the anatomy of the ACL, and its surgical application in its reconstruction are concerned. Also, it is significant to take into account the anatomy as far as the rehabilitation protocol is concerned. Separate placement in the femoral side is known to give better results from transtibial approach. The medial tibial eminence and the intermeniscal ligament may be used as landmarks to guide the correct tunnel placement in anatomic ACL reconstruction. The anatomic centrum of the ACL femoral footprint is 43xa0% of the proximal-to-distal length of lateral, femoral intercondylar notch wall and femoral socket radius plus 2.5xa0mm anterior to the posterior articular margin. Some important factors affecting the surgical outcome of ACL reconstruction include graft selection, tunnel placement, initial graft tension, graft fixation, graft tunnel motion and healing. The rehabilitation protocol should come in phases in order to increase range of motion, muscle strength and leg balance, it should protect the graft and weightbearing should come in stages. The cornerstones of such a protocol remain bracing, controlling edema, pain and range of motion. This should be useful and valuable information in achieving full range of motion and stability of the knee postoperatively. In the end, all these advancements will contribute to better patient outcome. Recommendations point toward further experimental work with in vivo and in vitro studies, in order to assist in the development of new surgical procedures that could possibly replicate more closely the natural ACL anatomy and prevent future knee pathology.

ACL reconstruction with semitendinosus tendon autograft without detachment of its tibial insertion: a histologic study in a rabbit model

The purpose of this study was to evaluate the histologic changes that occur between 3 and 12xa0weeks in an intra-articular, semitendinosus autograft, which was harvested without detachment of its tibial insertion and was placed through tibial and femoral drill holes, in a rabbit model. About 30 New Zealand white rabbits underwent ACL replacement using a semitendinosus tendon autograft. The normal ACL was transected at its femoral and tibial insertions. The tendon graft was harvested without detachment of its tibial insertion and its free end was secured with sutures. The graft was then passed through one tibial and one femoral tunnel and secured at the lateral femoral condyle. All animals were divided into three groups and were killed at 3, 6 and 12xa0weeks after surgery. Nine more animals underwent ACL reconstruction using a free semitendinosus tendon autograft. These animals were used as controls. The intra-articular portion of the graft and the interface between the bone tunnel and the graft was evaluated postoperatively for gross morphology and histological appearance. Results of this study showed that in a rabbit model the semitendinosus tendon autograft retained its viability when harvested without detachment of its peripheral insertion. On contrary, at the control group, necrosis of the graft was observed 3xa0weeks after surgery and progressively revascularization and maturation occurred 6 and 12xa0weeks after surgery. Retaining the tibial insertion of the semitendinosus autograft seems to preserves its viability and bypasses the stages of avascular necrosis and revascularization that occurs with the use of a free tendon autograft.

Computerized Tomographic Morphometric Analysis of the Cervical Spine

Background: Detailed knowledge of cervical canal and transverse foramens’ morphometry is critical for understanding the pathology of certain diseases and for proper preoperative planning. Lateral x-rays do not provide the necessary accuracy. A retrospective morphometric study of the cervical canal was performed at the authors’ institution to measure mean dimensions of sagittal canal diameter (SCD), right and left transverse foramens’ sagittal (SFD) and transverse (TFD) diameters and minimum distance between spinal canal and transverse foramens (dSC-TF) for each level of the cervical spine from C1-C7, using computerized tomographic scans, in 100 patients from the archives of the Emergency Room. Results: Significant differences for SCD were detected between C1 and the other levels of the cervical spine for both male and female patients. For the transverse foramen, significant differences in sagittal diameters were detected at C3, C4, C5 levels. For transverse diameters, significant differences at C3 and C4 levels. A significant difference of the distance between the transverse spinal foramen and the cervical canal was measured between left and right side at the level of C3. This difference was equally observed to male and female subjects. Conclusion: CT scan can replace older conventional radiography techniques by providing more accurate measurements on anatomical elements of the cervical spine that could facilitate diagnosis and preoperative planning, thus avoiding possible trauma to the vertebral arteries during tissue dissection and instrument application.

Morphometric analysis of the odontoid process: using computed tomography--in the Greek population.

AbstractAimA morphometric analysis of the odontoid process of the A2 vertebra, in the Greek population, was conducted using CT scan. nWe aimed to determine the feasibility to use one or two screws when treating fractures of this anatomic element.Patients and methodsOne hundred and fifteen patients (57 men) of a mean age of 48xa0years (16–95xa0years) underwent a cervical spine CT scan examination. The anterior–posterior and transverse diameters of the odontoid process were measured from the base, at 1-mm interval upward on axial CT images. The length from the tip of the odontoid process to the anterior–inferior angle of the body of the axis was calculated. Data concerning the height and weight of the examined patients were collected.ResultsThe mean transverse and anterior–posterior distances were found to be 11.46 and 10.45xa0mm, respectively, for the upper end of the odontoid process. At the neck level of the odontoid process, the equivalent mean values were 11.12 and 8.73xa0mm, respectively, while at the base, these distances were found to be 13.84 and 12.3xa0mm, respectively. The mean distance from the tip of the odontoid to its base was 17.25 and 17.28xa0mm, respectively, while the mean distance from the tip of the dens to the anterior–inferior corner of the axis’ body was 39.2xa0mm. Men showed greater values than women.ConclusionsIn this study, it was shown that in the Greek population there is enough room for one 4.5-mm or one 3.5-mm cannulated screw to be used. The application of two 3.5-mm screws is feasible in 58.6xa0% of the male and 26.3xa0% of the female population. This confirms that the knowledge of the true dimensions of the odontoid process is of paramount importance before the proper management of fractured dens using the anterior screw technique.

Symptomatic intracranial abscess after treating lower cervical spine fracture with halo vest: a case report and review of literature.

We present the case of a nineteen year old male, who sustained a fracture of anterior-superior surface of C7, combined with anterior subluxation at the level of C6–C7 vertebrae. After x-ray and CT examination, he was treated conservatively by a Halo-vest. After mobilization, the patient was discharged from the hospital with instructions to visit the outpatients clinic at regular bases.Despite of our instructions, he did not attend the regular follow-up and, three months later, he visited the emergencies complaining of pin loosening and serious headaches. He was admitted to the clinic in order to perform blood tests and new radiological control. During the first day, high fever (over 38,5°C) was added to his symptoms. Blood exams were indicative of inflammation. Further investigation with CT-scan revealed the presence of a subdural abscess. After consulting the neurosurgeon, the patient was treated conservatively with antimicrobial drugs. Three weeks later he returned home without any symptoms. Since then, he is visiting regularly our clinic and no problems occurred during follow-up.

Anatomical considerations of C2 lamina for the placement of translaminar screw: a review of the literature

PurposeThe thorough knowledge of C2 lamina anatomy is essential for the avoidance of complications during screw fixation. We performed a review of the literature, aiming to detect what was found about anatomical feasibility of C2 translaminar fixation in different populations, along with possible recommendations for the avoidance of complications, and to detect whether factors such as race or gender could influence axis lamina anatomy and fixation feasibility.MethodsWe performed a search in PubMed and Cochrane database of systematic reviews for studies which correlated axis lamina anatomy with fixation feasibility. We extracted data concerning measurements on C2 lamina, the methods and conclusions of the studies.ResultsTwenty-six studies met our inclusion criteria. The studies mainly focused on Asian populations. Male gender was generally related to larger anatomical parameters of C2 lamina. The use of a C2 translaminar screw with a diameter of 3.5xa0mm was generally feasible, even in children, but there was disagreement about risk of vertebral artery injury. Computed tomography was most frequently recommended preoperatively. Three-dimensional reconstruction was suggested by some authors.ConclusionC2 lamina anatomy generally permitted screw fixation in most studies, but there was disagreement about risk of vertebral artery injury. Preoperative computed tomography was generally recommended, while, according to some authors, three-dimensional reconstruction could be essential. However, there is a relative lack of studies about non-Asian populations. More research could further illustrate the anatomy of C2 lamina, clarify the safety of axis fixation for more populations and perhaps modify preoperative imaging protocols.

Erratum to: Association between serum and synovial fluid Dickkopf-1 levels with radiographic severity in primary knee osteoarthritis patients

Primary knee osteoarthritis (OA) contributes to disability among middle-aged and elderly people. Dickkopf-1 (Dkk-1) and sclerostin are inhibitors of Wnt/β-catenin signaling pathway implicated in regulation of cartilage homeostasis and bone formation, respectively. We aim to investigate the association between the serum(s) and synovial fluid (SF) Dkk-1 and sclerostin levels and disease severity in patients with primary knee OA. Forty patients aged 56-87xa0years with primary knee OA and 20 healthy individuals were recruited. Weight-bearing anteroposterior radiographs of the affected knee were used to determine the disease severity according to Kellgren and Lawrence criteria. Dkk-1 and sclerostin levels in serum and SF were measured by ELISA. SF Dkk-1 levels were significantly higher in the OA, compared to control group (180xa0±xa0182 vs 128xa0±xa0330xa0pg/ml, pxa0<xa00.001). However, OA patients did not differ significantly regarding the sDkk-1 concentrations compared to healthy controls (1289.8xa0pg/ml vs 1214.1, respectively, pxa0=xa00.630). SF Dkk-1 levels in Kellgren and Lawrence (KL) grade 4 were significantly elevated compared to those of KL grades 2 and 3 (1.97 vs 2.23xa0pg/ml, pxa0=xa00.017, log transformed because data were not normally distributed), whereas sDkk-1 levels between those groups demonstrated marginally statistically significant difference (1111.8 vs 1415.9xa0pg/ml, pxa0=xa00.057). SFSclerostin and sSclerostin levels did not have any significant difference between the OA and control groups. SF Dkk-1 levels are positively related to the severity of joint damage in knee OA. Sclerostin levels failed to substantiate an association to knee OA progression. Dkk-1 could play a potential role in the degenerative process of OA. Thus, DKK-1 may emerge as a promising future therapeutic manipulation of OA.

Fractures of the Vertebral Body

Fractures of the body of the axis represent a separate entity; the body itself is an anatomical area well recognized. Many authors paid particular attention and have already described these lesions. Initially, authors referred to as a non-hangman, non-odontoid fracture, but we believe that these fractures could be covered under one label that is fractures of the body of the axis. This lesion is frequent, accounting for about 11 % in our series. The following patterns of fractures have been distinguished: a. tear drop fractures of the axis (or avulsion), b. transverse fractures of the body, c. vertical, and d. miscellaneous. These fractures are described, and proper treatment is given.