Lateral popliteal sciatic nerve block: a single injection targeting the tibial branch of the sciatic nerve is as effective as a double-injection technique

BACKGROUND: Evidence indicating that single- and double-injection techniques for inducing a sciatic nerve block via a posterior subgluteal approach yield a similar success rate prompted us to investigate whether the two anesthetic techniques yield a similar success rate via a lateral approach. We also hypothesized that, owing to the peculiar anatomic features of the sciatic nerve at the popliteal level, a single injection via the lateral approach might induce effective anesthesia by targeting the tibial nerve only. METHODS: Ninety-six patients undergoing popliteal sciatic nerve block via a lateral popliteal approach for foot surgery were randomized to receive a single 30-ml injection of ropivacaine 7.5 mg/ml to block the tibial nerve (TN group, n= 32) or the common peroneal nerve (CPN group, n= 32), or two separate 15-ml injections (TN + CPN group, n= 32), after stimulation to evoke motor responses from the target nerves. RESULTS: The mean time to obtain a complete sensory blockade (surgical anesthesia) was shorter in the TN group than in the CPN and TN + CPN groups (14 +/- 7 min vs. 23 +/- 17 and 21 +/- 14 min, respectively; P < 0.05). The success rate was similar in the TN and TN + CPN groups (94%) and, 25 min after the initial injection, was already better in these groups than in the CPN group (94% vs. 75%; P < 0.05). CONCLUSIONS: A lateral popliteal sciatic nerve block obtained with a single 30-ml injection of ropivacaine 7.5 mg/ml after electrostimulation to locate the tibial nerve is as effective as multiple TN + CPN stimulation and injection, and local anesthesia has a significantly shorter onset time.     

Integrated treatment of secondary hepatolithiasis. Case report

Hepatolithiasis is defined as the occurrence of stones proximal to the biliary confluence and represents a prevalent disease in South East Asia being uncommon in Western countries. Biliary sepsis, hepatic abscesses and cholangiocarcinoma are considered potential complications. The Authors describe a case of a 68 years male patient affected by a left massive intrahepatic lithiasis secondary to common duct stones and associated to acute pancreatitis. The patient refused surgery and was submitted to a conservative transhepatic percutaneous treatment. After a complete removal of intrahepatic stones and a positioning of external internal biliary drainage (14F), a laparoscopic cholecistectomy was performed. The MRI control showed a complete resolution of the intrahepatic lithiasis. Conservative transhepatic percutaneous approach to hepatolithiasis represents a safe and effective treatment allowing good medium-long term results. Surgery is recommended in case of severe hepatic fibrosis or atrophy, suspected cholangiocarcinoma or multiple strictures with biliary distorsion. Integrated therapeutical protocols in referral multidisciplinary centers-offers the best long term results.     

A new technique for removing intramedullary cement

Treatment of infected long bone fractures or nonunions requires stability for bony union, yet retained implants can lead to persistent infection. Antibiotic cement intramedullary nails, in addition to external fixation, are commonly used to deliver intramedullary antibiotics in infected long bone fractures and provide temporary stability. However, the retrieval of these nails can result in debonding of antibiotic cement, which can require significant time and effort to remove. A variety of methods, including intramedullary hooks, reverse curettes, flexible osteotomes, and stacked guide rods, are commonly used to remove cement fragments. When these methods fail to allow access to the entire length of the canal, the Reamer Irrigator Aspirator system (Synthes, Paoli, PA) serves as an effective method for removing retained intramedullary cement. The surgical technique is described, and three cases illustrate the successful use of the Reamer Irrigator Aspirator system for removal of an antibiotic cement intramedullary nail.     

Synovial healing in reconstructed cruciate ligaments. Our personal experience compared in single interventions and combined reconstructions

INTRODUCTION: The healing process of tendon grafts used in cruciate ligament reconstruction is called ligamentization. The tendon structural architecture changes progressively into the histological appearance of normal ligament. Amiel and Clancy have demonstrated that this process is time-dependent in anterior cruciate ligament (ACL) reconstruction, the tendon graft taking one year to become similar to a normal cruciate ligament. Three different maturation phases of anterior cruciate graft ligamentization can be seen at MRI: periligamentous proliferation, intraligamentous proliferation and definitive healing. We report our MR findings in the reconstruction of single ACL, posterior cruciate ligament (PCL), and of both ACL and PCL. MATERIAL AND METHODS: January 1995 to January 1999 we selected 60 patients submitted to arthroscopic cruciate ligament reconstruction. The ACL was reconstructed with the patellar tendon in 22 cases and the PCL in 23; fifteen patients underwent double reconstruction of ACL, with hamstring tendons, and PCL, with patellar tendons. Fifty-five patients were followed-up with MRI: 45 with a dedicated permanent magnet (Artroscan, Esaote Biomedica, Genoa, Italy) and 10 with a permanent low-field unit (AIRIS, Hitachi, Japan); the same technical parameters were used in all cases. Forty of 55 patients were examined at 1, 3, 6, 9 and 12 postoperative months, while 15 were followed-up longer (12 to 36 months postoperatively). At the first follow-up MR examination, 5 patients (2 ACL and 3 PCL) were excluded for incorrect tunnel position (1 case), hypertrophic scarring (2 cases) and new trauma (2 cases). MR findings were compared with clinical data of joint stability. RESULTS: MRI showed the different stages of the healing process in 20 ACL patients: proliferating soft tissue around the graft with the low signal intensity typical of tendons (stage I, 1-3 months postoperatively), the graft becomes progressively hyperintense (stage II, 3-9 months postoperatively), and finally the low signal intensity indicating completed ligamentization (stage III, 12 months postoperatively). As for PCL reconstructions, MR findings were similar but the process took longer, even 24 months. Finally, in the 15 cases of double reconstruction, both grafts were difficult to distinguish on T1-weighted images for a very long time (24-36 months postoperatively). DISCUSSION AND CONCLUSIONS: Relative to the ACL, ligamentization takes longer for PCL and combined ACL and PCL reconstructions, probably because the morphological changes in PCL and double grafts may be impaired by many factors, such as gravity, long bone tunnels, hemarthrosis, hyperplastic synovial reaction in the intercondylar notch; also, rehabilitation protocols differ in ACL from PCL patients. No signs of instability were found at physical or arthrometric examinations. MRI demonstrates the different stages of ligamentization and thus proves a useful tool for postoperative follow-up in cruciate ligament reconstructions. Contrast-enhanced (Gd) studies are reserved to the cases of graft impingement or if other abnormalities are suspected.     

Activation of Coagulation and Fibrinolysis during Coronary Surgery: On-pump versus Off-pump Techniques

Background : The authors studied the changes in selected hemostatic variables in patients undergoing coronary surgery with on-pump coronary artery bypass grafting (CABG) or off-pump coronary artery bypass surgery (OPCAB) techniques.

Methods : Platelet counts and plasma concentrations of antithrombin, fibrinogen, D dimer, [alpha]2 antiplasmin, and plasminogen were measured preoperatively, 5 min after administration of heparin, 10 min after arrival in the intensive care unit, and 24 h after surgery in patients scheduled to undergo OPCAB (n = 15) or CABG (n = 15). To correct for dilution, hemostatic variables and platelet counts were adjusted for the changes in immunoglobulin G plasma concentrations and hematocrit, respectively.

Results : Adjusting for dilution, antithrombin and fibrinogen concentrations decreased to a similar extent in patients undergoing OPCAB or CABG (pooled means and 95% confidence limits of the mean: 95.5% of baseline, 93-98%, P = 0.002, and 91.7% of baseline, 88-95%, P = 0.0001), respectively, whereas [alpha]2-antiplasmin concentrations were unchanged. Only CABG was associated with a reduction in platelet counts (76% of baseline, 66-85%, P = 0.0001), plasminogen concentrations (96% of baseline, 91-99%, P = 0.011), and increased D-dimer formation (476%, 309-741%, P = 0.004). Twenty-four hours after surgery, platelet counts were still lower in patients undergoing CABG (P = 0.049), but all the investigated variables adjusted for dilution were similar in the two groups.     

Porous tantalum in reconstructive surgery of the knee: a review

Porous tantalum represents an alternative metal for primary and revision total knee arthroplasty (TKA) with several unique properties. Tantalum is a transition metal, which in its bulk form has shown excellent biocompatibility and is safe to use in vivo as evidenced by its current application in pacemaker electrodes, cranioplasty plates, and as radiopaque markers. Current designs for orthopedic implants maintain a high volumetric porosity (70%-80%), low modulus of elasticity (3 MPa), and high frictional characteristics, making this metal conducive to biologic fixation. The low modulus of elasticity of such components allows for more physiologic load transfer and relative preservation of bone stock. Its more bioactive nature and ingrowth properties have led to its use in primary as well as revision knee components with good early clinical results reported. In revision arthroplasty, it has been used as a structural bone graft substitute. Formation of a bone-like apatite coating in vivo affords strong fibrous ingrowth properties and allows for substantial soft-tissue attachment with the potential for use in cases such as mega-prostheses and patella salvage. Although porous tantalum is in its early stages of evolution, the initial clinical data and basic science studies support its use as an alternative to traditional orthopedic implant materials.     

Prognosis of isolated acute post-traumatic subdural haematoma

AIM: Acute subdural haematoma (ASDH) is seldom an isolated lesion and it is difficult to understand the mechanisms which determine the poor prognosis associated to this occurrence. Aim of this study was estimating the outcome of patients with ASDH without any companion lesions by analysing the haematoma volume, its thickness and midline shift. METHODS: Twenty-eight severely head injured patients (Glasgow Coma Scale, GCS =/<8) with isolated unilateral ASDH admitted in intensive care unit (ICU) were retrospectively studied. The haematoma thickness, the midline shift, the ASDH volume were obtained from the first emergency computerized tomography (CT) scan and analysed by a computer assisted programme (Osiris). Patients' outcome was scored according to the Glasgow Outcome Scale (GOS) 6 months after the event. According to their GOS the patients were further divided in 2 groups (favourable outcome: GOS 4-5, poor outcome: GOS 1-2-3). RESULTS: Midline shift ranged from 0 to 19.2 mm; we found a larger midline shift in those patients who died and in patients with severe disability or vegetative state 6 months after the trauma. CONCLUSION: The presence and size of midline shift was a more important determinant of outcome than ASDH volume or its thickness.     

WNT pathway signaling is associated with microvascular injury and predicts kidney transplant failure

Microvascular injury is associated with accelerated kidney transplant dysfunction and allograft failure. Molecular pathology can identify new mechanisms of microvascular injury while improving on the diagnostic and prognostic capabilities of traditional histology. We conducted a case‐control study of archived kidney biopsy specimens stored up to 10 years with microvascular injury (n = 50) compared with biopsy specimens without histologic injury (n = 45) from patients of similar age, race, and sex. We measured WNT gene expression with a multiplex quantification platform by using digital barcoding, given the importance of WNT reactivation to the response to wounding in the kidney microvasculature and other compartments. Of 210 genes from a commercial WNT panel, 71 were associated with microvascular injury and 79 were associated with allograft failure, with considerable overlap of genes between each set. Molecular pathology identified 46 biopsy specimens with molecular evidence of microvascular injury; 18 (39%) were either C4d negative, donor‐specific antibody negative, or had no microvascular injury by histology. The majority of cases with molecular evidence of microvascular injury had poor long‐term outcomes. We identified novel WNT pathway genes associated with microvascular injury and allograft failure in residual clinical biopsy specimens obtained up to 10 years earlier. Further mechanistic studies may identify the WNT pathway as a new diagnostic and therapeutic target.