Proximal Hole Research Articles

Failed spinal anaesthesia after intrathecal chemotherapy

Failed spinal anaesthesia after intrathecal chemotherapy

Synergistic Effects of D‐Glucosamine and Collagen Peptides on Healing Experimental Cartilage Injury

AbstractWe investigated the synergistic wound‐healing effects of D‐glucosamine (GlcN) and collagen peptide ($\overline M _{\rm w}$: 10 000 Daltons soluble collagen (S‐Co)) on injured cartilage. A injured cartilage model in rabbit was surgically created. Under general anesthesia, three holes at articular cartilage of the medial trochlear (one hole) and trochlear sulcus (two holes) of a distal femur were created using a high‐speed orthopedic drill. After surgery, rabbits were orally administered with collagen peptide (S‐Co group), GlcN (G group), or both (CoG group) for 2 or 3 weeks. In addition, glycine (Gly group) was administered as a control for the S‐Co group in three rabbits. Control rabbits were provided with water ad lib. After 2 weeks, the holes were filled by fibroblasts and chondroblasts in the treatment group, whereas in the control group, the holes were not filled completely unlike for the treatment group. Even three weeks later, only a small change was seen in the control group. In the group receiving collagen and GlcN, the holes were completely filled by proliferating chondroblasts, remodeling of bony trabeculae was also observed. Image analysis of Safranin O‐ and Alcian blue‐stained specimens showed increased production of proteoglycans and glycosaminoglycans, respectively, not only in the injured site, but also in the normal cartilage in the treated groups. The most enhanced healing of injury and increase in Safranin O and Alcian blue positive materials was observed in the CoG group. As a result, simultaneous administration of collagen and GlcN gave a fairly enhanced healing on restoration of cartilage injuries.Artificial cartilage injury at the stifle joint of a rabbit. a: proximal hole in trochlear sulcus; b: distal hole in trochlear sulcus; c: medial hole in medial trochlear ridge.magnified imageArtificial cartilage injury at the stifle joint of a rabbit. a: proximal hole in trochlear sulcus; b: distal hole in trochlear sulcus; c: medial hole in medial trochlear ridge.

Enhanced healing of cartilaginous injuries by N-acetyl- d-glucosamine and glucuronic acid

We investigated the restorative effect of orally administered glucose, N-acetyl- d-glucosamine (GlcNAc) and glucuronic acid (GlcUA) on the experimentally produced cartilaginous injuries in rabbits. A total of three holes in the left stifle joint, including one in the medial trochlear ridge, and two in the trochlear sulcus (proximal and distal) of articular cartilage were made surgically using a drill. For the control group, only tap water was administered daily and for the glucose, GlcNAc, GlcUA groups, a water based solution (1 g/head/day) of glucose, GlcNAc, glucuronolactone was administered daily, respectively. We observed the clinical symptoms daily and the condition of the injured part was observed macroscopically and histologically at 3 weeks after the operation. There was no difference in body weight or general conditions among each group. With respect to medial trochlear injury, 1/3 holes were not cured in the control, but all were cured in the glucose, GlcNAc and GlcUA groups, respectively. With respect to the proximal hole, 4/6 in the control group, 3/3 in the glucose and 2/3 in the GlcNAc were not cured. However, 2/3 in the GlcUA were cured. There was significant difference ( p<0.05) in the proximal holes between the control and the GlcUA. On the total points, there was significant difference ( p<0.05) between the control and GlcNAc or GlcUA. On histological examination, the injured parts were covered by fibrous connective tissues in the control and the glucose, whereas in the GlcNAc and GlcUA groups, the massive proliferation of matured cartilaginous tissues was observed, and the regenerated cartilaginous tissues were surrounded by the proliferation of chondroblast cells. In the regenerated tissue, matured cartilage substrate was also observed. Safranin O and Alcian blue stains marked a more significantly dense in the GlcNAc and GlcUA group than in the control ( p<0.01) in injured parts as well as in non-injured joint cartilage.

Computational and experimental study of proximal flow in ventricular catheters. Technical note.

The treatment of hydrocephalus with shunt insertion is fraught with high failure rates. Evidence indicates that the proximal holes in a catheter are the primary sites of blockage. The authors have studied ventricular catheter designs by using computational fluid dynamics (CFD), two-dimensional water table experiments, and a three-dimensional (3D) automated testing apparatus together with an actual catheter. With the CFD model, the authors calculated that 58% of the total fluid mass flows into the catheter's most proximal holes and that greater than 80% flows into the two most proximal sets of holes within an eight-hole catheter. In fact, most of the holes in the catheters were ineffective. These findings were experimentally verified using two completely different methodologies: a water table model of a shunt catheter and a 3D automated testing apparatus with an actual catheter to visualize flow patterns with the aid of ink. Because the majority of flow enters the catheter's most proximal holes, blockages typically occur at this position, and unlike blockages at distal holes, occlusion of proximal holes results in complete catheter failure. Given this finding, new designs that incorporated varying hole pattern distributions and size dimensions of the ventricular catheter were conceived and tested using two models. These changes in the geometrical features significantly changed the entering mass flow rate distribution. In conclusion, new designs in proximal ventricular catheters with variable hole diameters along the catheter tip allowed fluid to enter the catheter more uniformly along its length, thereby reducing the probability of its becoming occluded.

Enhanced healing of cartilaginous injuries by glucosamine hydrochloride

We investigated the restorative effect of orally administered glucosamine hydrochloride (GlcN) on the experimentally produced cartilaginous injuries in rabbits. A total of three holes in the left stifle joint including one in the medial trochlear ridge and two in the trochlear sulcus (proximal and distal) of articular cartilage were made surgically using a drill. For the control group, only tap water and for the glucosamine group, a water based solution of GlcN (1 g/head) was administered daily, respectively. We observed the clinical symptoms daily and the condition of the injured part was observed visually and histologically at 3 weeks after the operation. There was no difference in body weight or general conditions between the two groups. However, in the control group, the muscle weight of the biceps of the left femur was significantly reduced ( p<0.05). With respect to the medial trochlear injury, four out of six cases in the control group and five out of six cases in the glucosamine group were cured, respectively. With respect to the proximal and the distal holes in sulcus, only two out of six cases in the control group and five expansive out of six cases in the glucosamine group were cured. There was significant difference between the glucosamine group and the control with respect to healing of the proximal hole ( p<0.05) and the total points ( p<0.05), indicating that the artificial cartilage injuries were facilitated by GlcN. On histological examination, the injured parts were covered by fibrous connective tissues in the control, whereas in the glucosamine group, the massive proliferation of matured cartilaginous tissues was observed, and the regenerated cartilaginous tissues were surrounded by the proliferation of chondroblast cells. In the regenerated tissue, matured cartilage substrate was about to be formed. Safranin O and alcian blue stains marked significantly dense in the glucosamine group than in the control ( p<0.01) in injured parts as well as in non-injured joint cartilage.

A new interlocking dynamic compression nail for tibial shaft fractures

The Clos tibial nail is a cannulated cylindrical nail that permits static, dynamic as well as incompression mounting by the insertion of locking screws into distal and proximal holes. From September 1998 to March 1999 we treated 16 tibial shaft fractures with CLOS tibial nails. All fractures were managed with calcanear traction, closed reduction, reaming and fixation. Patients were followed for at least 1 year. The mean time to full weight bearing was 11 (10–14) weeks. There were no cases of delayed union or dynamization. All patients returned to their previous activity levels.

Experimental study of the hydrodynamic effects of irrigation suction drainage.

The function of irrigation suction drainage, as an additional method in the treatment of bone infection, is associated with hydrodynamic problems that can only be experimentally examined. The visualization of liquid movement in the experimental model was realized by adding a colored ink to the input drain of the drainage system. When only 2000 ml of liquid was used daily (80 drops/min), the ink penetrated the experimental cavity only through the most proximal holes in the input drain. It spread slowly and irregularly through the liquid in the experimental bottle, forming pocket deposits and leaving sediment. When 6000 ml of liquid was applied daily (240 drops/min), ink quickly penetrated the cavity through all holes in the drain, leading to turbulence and dispersing equally in the bottle. Decoloration of the model bottle was faster because the output drainage was more efficient. With an increased flow, i.e., with more liquid used in the drainage, a better result was achieved. This was manifested in a swift decoloration and rinsing of the cavity.

New retrieval balloon catheter with a blind top and proximal side hole for fine bile duct fragments produced by lithotripsy

New retrieval balloon catheter with a blind top and proximal side hole for fine bile duct fragments produced by lithotripsy

Application of a hook plate for management of equine ulnar fractures.

Closed fractures of the proximal aspect of the ulna were repaired in 10 horses younger than or equal to 6 months of age by application of a hook plate using a tension band principle. Ulnar fractures were classified as type 1A (2 horses), type 1B (4 horses), type 2 (1 horse), type 3 (1 horse), and type 4 (2 horses); all fractures had displacement of a proximal fragment. Complications were implant deformation (4 horses), screw pullout (1 horse), osseous sequestration (1 horse), ulnar fracture through a hole used to apply a tension device (1 horse), and metacarpophalangeal deformity associated with a displaced anconeal fragment (1 horse). Hook deformation was likely associated with failure to insert screws in all of the proximal holes of the plate and also in two horses, possibly with difficult recovery from anesthesia. Seven horses were discharged from the hospital and were being used for athletic activities. Insertion of the hook through the tendon of the triceps muscle and incorporation of the fragment within the hook can be used to effectively reduce and stabilize a fragment that might otherwise not hold screws.

Sclerotherapy of the Gallbladder in Pigs

Gallbladder sclerotherapy after permanent cystic duct occlusion, to prevent gallstone recurrence in nonsurgical gallstone therapy, is at least a two-stage procedure. A balloon catheter was developed to perform gallbladder sclerotherapy with only temporary occlusion of the cystic duct, and the efficacy and safety of this method was subsequently investigated. Twenty pigs underwent cholecystostomy for positioning of a 7-Fr triple-lumen balloon catheter with proximal side holes. Sclerotherapy with 96% ethanol and 3% sodium tetradecyl sulfate for 20 minutes was performed. The animals were killed 24 hours, two, six, and 12 weeks after the procedure. The balloon catheter functioned well and seems suitable for procedures in which a temporary occlusion of the cystic duct is required. Although gallbladders after six and 12 weeks were shrunken and fibrotic, a single treatment of gallbladder sclerotherapy with subsequent catheter removal and no permanent cystic duct occlusion, as performed in this experiment, did not produce complete gallbladder ablation. In this study, sclerotherapy proved safe in the short term, but long-term effects remain to be assessed.

Distal Screw Targeting of Interlocking Nails

Successful placement of the distal interlocking screws into the Grosse-Kempf nail is a demanding procedure due in part to deformation of the nail during insertion and to inaccuracy of the targeting device supplied with the system. The authors suggest an alternative approach. After placement of the nail in a tibia or femur, a Kirschner wire (K-wire) is directed through the distal transfixation hole under fluoroscopic control. A second Grosse-Kempf nail is placed alongside the limb with the K-wire passing through the corresponding distal hole. The more proximal hole on the nail serves as a targeting guide for a more proximal wire. Once correct placement of the wires is confirmed roentgenographically, the near cortex is opened with a cannulated drill passed over the wires. The wires are removed, the opposite cortices are drilled, and the screws are placed. In 25 consecutive distally locked nailings (eight tibiae and 17 femora), the technique was easily mastered, decreasing the roentgenogram exposure when compared to freehand techniques.

Administration of Hypothermic Cardioplegia in the Presence of Aortic Regurgitation

Two technical maneuvers are presented to make the administration of cardioplegia feasible in the presence of moderate aortic valve incompetence. In the first maneuver, the cardioplegic solution is administered through a double-lumen balloon catheter inserted retrograde through the aortic wall and the aortic valve into the left ventricle; the inflated balloon obstructs the aortic orifice while the solution is injected through the proximal hole. In the second, after proximal anastomoses of the saphenous vein grafts are performed, the portion of the aorta from which the vein grafts rise is excluded by double cross-clamping and the cardioplegic solution is injected into this excluded segment.

Biochemical disturbances associated with total hip replacement

A prospective study on 227 patients undergoing arthroplasty of the hip was carried out with reference to the effects on the cardiovascular and respiratory systems. Investigations revealed that the placing of acrylic bone cement and the prosthesis in the femoral shaft produced clinical and biochemical disturbances which were consistent with pulmonary microembolism. A fall in arterial oxygen tension during the procedure and hypoxaemia extending into the postoperative period with elevation of serum lipase and a fall in triglycerides supported the idea that embolisation with marrow fat occurred. The method of venting (by catheter or proximal hole) did not influence the biochemical disturbances. The implications of these findings are discussed.