Papers by Francisco Reina
The speed of the cutting blades is one of the main factors that allow cutting without a counter e... more The speed of the cutting blades is one of the main factors that allow cutting without a counter edge and this depends on the diameter of the trajectory, the inertia, the stem's resistance to fl exion and on the maximum cutting force of the apparatus. The energy and the cutting power of mowers and shredders also depend on the knives speed, on the feed speed, on the crop properties, on the knives' cutting width and on the number of blades cutting simultaneously ; Moore Almeida and Benez, 1997). Abstract J.S. Pérez de Corcho Fuentes, F. Garbati Pegna, C. Iglesias Coronel, F. García Reina, and P. Spugnoli. 2009. Power demand of fl ail mower during fi eld demolition of pineapple fi elds. Cien. Inv. Agr. 36(1): 59-68.
Objetivo: Describir las distancias entre las principales estructuras óseas, vasculares, neurológi... more Objetivo: Describir las distancias entre las principales estructuras óseas, vasculares, neurológicas y viscerales que son relevantes para guiar el paso de las agujas insertoras en las técnicas quirúrgicas a través del foramen obturador.
Morphological features in human cortical brain microvessels after head injury: A three-dimensional and immunocytochemical study
The Anatomical Record, 2003
We studied the morphology of cortical microvessels in the brains of 10 patients who had died afte... more We studied the morphology of cortical microvessels in the brains of 10 patients who had died after receiving a traumatic head injury (THI). Scanning electron microscopy (SEM) of vascular corrosion casts, confocal microscopy of histological sections after immunocytochemistry, and detection of apoptosis by terminal dUTP nick end labeling (TUNEL) were used. Microvascular casts showed an angioarchitectonic distribution that was defined as normal according to results obtained in a previous, nontraumatic series of subjects. However, when we compared them with previous works, the cast surface of some of the microvessels showed three types of morphological alterations: longitudinal folds, sunken surfaces with craters, and a significant flattening with reduction of lumen. The vessels that were primarily affected were the arterioles and capillaries of the middle and deep cortical vascular zones. Immunostaining with the monoclonal antibody MAS-336 against endothelial cells also showed the presence of longitudinal folds with a thinning of the vascular lumen, cytoplasmic round bodies, and a thickening of the endothelial cell membrane. The TUNEL technique revealed a positive staining of some endothelial cells.The structural alterations we observed indicate that microvessels undergo endothelial cell damage after THI. We suggest that this kind of lesion and the secondary functional injury to the blood–brain barrier (BBB) could play an important role in the development of the secondary lesions that these patients show in the subacute phase. Anat Rec Part A 273A:583–593, 2003. © 2003 Wiley-Liss, Inc.
Clinical Anatomy, 2006
Although the Inferior Glenohumeral Ligament (IGHL) has a well known mechanical and proprioceptive... more Although the Inferior Glenohumeral Ligament (IGHL) has a well known mechanical and proprioceptive relevance in shoulder stability, the interrelation of the ligament's anatomical disposition/innervation has not actually been described previously. The purpose of the study was to determine the IGHL innervation patterns and relate them to dislocation. Forty-five embalmed and 16 fresh-frozen human cadaveric shoulders were studied. Masson's Trichrome staining detailed the intraligamentous nerve fiber arrangements. The effect on the articular nerves of an anteroinferior dislocation of the shoulder joint and the position of 60° abduction and 45° external rotation was studied dynamically. The axillary nerve provided IGHL innervation in 95.08% of the cases. We saw two distinct innervation patterns originating from the axillary nerve. In Type 1, one or two collaterals diverged later from the main trunk to enter the ligament. Type 2 showed innervation to the ligament provided by the posterior branch for three to four neural branches. In both cases, these branches enter the ligament near the glenoid rim and at the 7 o'clock position (right shoulder). The radial nerve (Type 3 innervation pattern) provided IGHL innervation in 3.28% of the cases. Microscopic analysis revealed wavy intraligamentous neural branches. The articular branches relaxed and separated from the capsule at the apprehension position and stayed intact after dislocation. These results showed a special predisposition to avoid possible denervation and suggested that the neural arch probably remains unaffected after most dislocations. Knowledge of the neural anatomy of the shoulder will clearly help in avoiding its injury in surgical procedures. Clin. Anat. 19:304–311, 2006. © 2005 Wiley-Liss, Inc.
American Journal of Sports Medicine, 2010
Background: A more oblique placement of the anterior cruciate ligament (ACL) graft has been relat... more Background: A more oblique placement of the anterior cruciate ligament (ACL) graft has been related to better control of rotatory knee stability. Femoral fixation with a transverse system might injure its posterolateral structures.
Arthroscopy-the Journal of Arthroscopic and Related Surgery, 2010
Purpose: The purpose of this study was to assess the risk of injury to the posterolateral structu... more Purpose: The purpose of this study was to assess the risk of injury to the posterolateral structures of the knee when performing anterior cruciate ligament reconstruction from the anteromedial portal while fixing the graft with a femoral cross-pin system. Methods: The anterior cruciate ligament was reconstructed arthroscopically with hamstring graft in 10 fresh cadaveric knees. Femoral fixation was performed with a cross-pin system. This was originally developed for a transtibial drilling technique. A femoral tunnel measuring 30 mm in length was drilled through the anteromedial portal in each knee. The knee flexion angle was set at 110°. Lateral dissection was then performed to measure the distances from the cross-pin system to the lateral collateral ligament, the popliteus tendon, the lateral gastrocnemius tendon, and the peroneal nerve. Results: The lateral collateral ligament was partially torn by the pin in 1 case. In 8 cases the distance to the lateral collateral ligament was shorter than 3 mm (range, 0 to 2.43 mm). In 7 specimens, the cross-pin system was within 4.5 mm of the popliteus tendon. The lateral gastrocnemius tendon was pierced by the cross-pin device in 2 cases. The minimal distance to the peroneal nerve was 23.89 mm. Conclusions: Fixation of a hamstring graft with a cross-pin system initially developed for an upper femoral tunnel, following the aforementioned technique, presents the possibility of a high risk of injury to the lateral collateral ligament. The popliteus tendon and the lateral gastrocnemius tendon may also be injured. Clinical Relevance: The risk of injury to the lateral stabilizers of the knee suggests discarding the technique used in this study.
Arthroscopy-the Journal of Arthroscopic and Related Surgery, 2007
Purpose: The purpose of this study was to assess, using a technique that minimally distorts the n... more Purpose: The purpose of this study was to assess, using a technique that minimally distorts the normal anatomy, the risk of injury when establishing a 5 o’clock shoulder portal in the lateral decubitus versus beach-chair position. Methods: The anteroinferior portal was simulated with Kirschner wires (K-w) drilled orthogonally at the 5 o’clock position in 13 fresh frozen human cadaveric shoulders. The neighboring neurovascular structures were identified through an anteroinferior window made in the inferior glenohumeral ligament. Their relations to the K-w and surrounding structures were recorded in both positions. Results: The median distance from the musculocutaneous nerve to the K-w was shorter in the lateral decubitus position than in the beach chair position (13.16 mm v 20.49 mm, P = .011). The cephalic vein was closer to the portal in the beach-chair position than in the lateral decubitus position (median 8.48 mm v 9.93 mm, P = .039). The axillary nerve was closer to the K-w in the lateral decubitus position than in the beach-chair position (median 21.15 mm v 25.54 mm, P = .03). No differences in the distances from the K-w to the subscapular and anterior circumflex arteries were found when comparing both positions. The mean percentage of subscapular muscle height from its superior border to the K-w was 53.03%. Conclusions: This study showed the risk of injury establishing a transubscapular portal in either position. The musculocutaneous nerve and the cephalic vein are the most prone to injury. In general, the beach-chair position proved to be safer. Clinical Relevance: Inserting anchor devices orthogonally would permit stronger fixation but presents the risk of damaging neurovascular structures. This study focused on showing the neurovascular risk of performing full orthogonal insertion. Considering the good results reported with the usual superior-anterior portals, we do not recommend performing a transubscapular portal in routine shoulder arthroscopy.
Knee Surgery Sports Traumatology Arthroscopy, 2008
Alterations in meniscal permeability leading to nutritional deficit have been suggested as a caus... more Alterations in meniscal permeability leading to nutritional deficit have been suggested as a cause of shrinkage in meniscal transplantation. The purpose of this study was to ascertain how freezing, one of the most common procedures used to preserve meniscal allografts, alters the collagen’s architecture. Twenty-six fresh human external menisci were analyzed with transmission electron microscopy. Thirteen of them were previously frozen at −80°C while the rest were used as controls. A new scale of the collagen meniscal architecture was proposed according to the collagen’s periodicity and degree of disruption, loss of banding, degree of collagen packing, fibril size variability and its intrafibrilar oedema. Each meniscus was scored from 0 to 7. Subsequently they were classified in grades ranging from a normal state (grade I; 0–2 points) to severe disarray (grade III; 5–7 points). The fibril collagen diameters of those menisci which had been previously frozen showed an average size in the longitudinal section of 14.26 nm, whereas it was 17.28 nm in the menisci used as controls (p = 0.019). In the transverse section, the frozen menisci averaged 13.14 and 16.93 nm in the controls (p = 0.003). Samples of the 13 previously frozen menisci were classified as grade III in 61.54% of the cases. In the control group, all the menisci were classified either as grade I or II. The frozen menisci averaged 4.85 points, whereas the control group did so at 2.46 (p < 0.001). The fibril diameters in frozen menisci showed a thinner diameter and had a higher degree of disarray. Therefore, the results suggest that the freezing process alters the menisci’s collagen net. This could partially explain the pathological changes found in shrunken menisci after transplantation.
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Papers by Francisco Reina