Investigation of the dose-dependency of citicoline effects on nerve regeneration and functional recovery in a rat model of sciatic nerve injury.

AIM: The aim of this study was to investigate the dose dependence of citicoline's previously-reported effects on recovery of peripheral nerve injury. MATERIAL AND METHODS: Right sciatic nerves of sixty adult female Wistar Albino rats were incised and primary anastomosis was performed. Rats were then divided into four groups: Control group received 2 ml of saline intraperitoneally, while rats in C-300, C-600 and C-900 groups received 300 µmol/kg, 600 µmol/kg and 900 µmol/kg citicoline dissolved in 2 ml saline, respectively. Rats were tested for sciatic functional index (SFI) on the 4th, 8th and 12th weeks and electrophysiological recordings were obtained on the 12th week. Rats were then sacrificed to investigate nerve adhesions and perform histomorphological examinations. RESULTS: Our results showed that rats in C-600 and C-900 groups had significantly lesser neural adhesion and greater SFI and electrophysiological score than those in the Control and C-300 groups (p < 0.05). Mean density and total number of functionally myelinated axons were significantly increased in C-900 group, while perineural scar tissue formation was reduced in all citicoline-treated groups. CONCLUSION: We conclude that citicoline exhibits dose-dependent effects on axonal regeneration and recovery without scar formation in a rat model of peripheral nerve incision and primary anastomosis.

Comparative results of percutaneous cannulated screws, dynamic compression type plate and screw for the treatment of femoral neck fractures.

BACKGROUND: The purpose of this study was to compare the period of union, functional outcomes and complications of patients with femoral neck fracture treated with percutaneous cannulated screws versus dynamic hip screw (DHS). METHODS: Sixty-six patients with femoral neck fracture were treated with percutaneous cannulated screws (n=33) or with DHS (n=33) between August 1999 and October 2003. Functional outcome was measured using Harris Hip Score, and period of union, amount of bleeding and complications were also recorded. RESULTS: The period of union and functional outcomes were not different between the two groups. Risk of avascular necrosis (AVN) was associated mainly with the grade of fracture displacement. In the percutaneous cannulated screw group, duration of surgery was shorter and blood loss was less than in the other group. CONCLUSION: There was no superiority between cannulated screws and DHS according to union times and functional results. Risk of AVN is related to the degree of displacement. However, a prospective randomized study is needed to determine the outcome of each technique for patients suffering similar displacement rates.

Enhancement of tendon-bone healing of anterior cruciate ligament grafts by blockage of matrix metalloproteinases.

BACKGROUND: The use of soft-tissue grafts for anterior cruciate ligament reconstruction delays the healing process. This delay may be due to biochemical and/or biomechanical insults. We hypothesized that the blocking effect of alpha2-macroglobulin on synovial matrix metalloproteinase activity may enhance the healing of tendon graft in a bone tunnel. METHODS: The study was performed on twenty-eight healthy, skeletally mature New Zealand White rabbits. Each rabbit underwent bilateral anterior cruciate ligament reconstruction with use of the ipsilateral semitendinosus tendon. Alpha-2-macroglobulin (alpha2-macroglobulin) was injected into the knee joint in one limb, and the contralateral limb served as a control. The rabbits were killed two weeks (fourteen rabbits) or five weeks (fourteen rabbits) after the operative procedures. The presence of matrix metalloproteinases in synovial fluid, and the blocking effect of alpha2-macroglobulin on them, were determined with enzymatic assays. Healing between the tendon and the bone tunnel was assessed morphologically by determining the presence of fibrovascular tissue and collagen fibers. Healing also was assessed quantitatively by measuring the ultimate load to failure of the reconstructed complex. RESULTS: There was an increase in matrix metalloproteinases in the control group; in contrast, there was a decrease in the study group (p < 0.05). In the control specimens, the fibrovascular tissue at the bone-tendon interface had developed into dense connective tissue with poor vascularization. In the treated specimens, the bone tunnel had more areas of denser connective-tissue ingrowth. The interface tissue was more mature and contained numerous perpendicular collagen bundles (Sharpey fibers). The ultimate load to failure was significantly greater in the alpha2-macroglobulin-treated specimens than in the untreated controls at both two and five weeks. CONCLUSIONS: The present study demonstrated that alpha2-macroglobulin blockade of matrix metalloproteinases can enhance bone-tendon healing. This effect of alpha2-macroglobulin could occur through its effect solely on collagenase or on a subset of matrix metalloproteinases that are present at the healing interface.

[The "false sense of absence" of the lower extremity below the knee: is it a specific sign for anterior cruciate ligament ruptures?]. / Yalanci yokluk duyusu: ön çapraz bag kopmasina özgü bir belirti olabilir mi?

OBJECTIVES: Patients whose anterior cruciate ligament (ACL) was completely ruptured described a feeling as if they had lost their lower extremity below the knee and gave an account that they had not sensed that part of their extremity at the time of ACL rupture. Thinking that this description might denote a diagnostic sign, an investigation was made to verify this feeling in patients whose ACL rupture was confirmed by knee arthroscopy. METHODS: The described feeling was named as "false sense of absence." A total of 135 patients with knee trauma were included. Those whose injuries were complicated or who had multiorgan injuries were excluded. The patients were divided into two groups according to whether they had ACL rupture (95 patients; 89 males, 6 females; mean age 28 years; range 15 to 50 years) or other knee injuries (40 patients; 34 males, 6 females; mean age 35 years; range 13 to 60 years). The above-mentioned symptom was questioned in both groups. RESULTS: The described symptom was found in 87% of patients with ACL rupture and in none of the patients with other knee pathologies (p<0.001). The specificity, sensitivity, positive and negative predictive values of this symptom in ACL ruptures were found as 100%, 98%, 100%, and 95%, respectively. CONCLUSION: The "false sense of absence" symptom, which has hitherto been undescribed in the literature, seems to occur in the majority of patients with ACL ruptures; it may be a specific and sensitive finding in determining ACL ruptures, and thus, may merit inclusion in the process of history taking.