Biomechanical analysis of distal femoral fracture fixation: dynamic condylar screw versus locked compression plate

Background This human cadaveric study introduces a laboratory model to establish and compare the fixation stability of the distal femoral locking plate (DFLP) and dynamic condylar screw (DCS) in distal femoral fracture fixation.Materials and methods The study was conducted on 16 fresh cadaveric femoral specimens, 8 implanted with the DCS and the other 8 with the DFLP. The construct was made unstable by removing a standard-sized medial wedge with a 1-cm base (gap osteotomy) beginning 6 cm proximal to the lateral joint line in the distal metaphyseal region with loss of the medial buttress. Each specimen underwent axial and torsional stiffness testing along with cyclic axial loading to failure. The mean DEXA value for the DFLP group was 0.82 g/cm² and in the DCS group was 0.79 g/cm².Results Axial stiffness in the DFLP group was significantly higher than in the DCS group, but no significant difference was found in torsional stiffness between the groups. A significant difference was found in the load-to-failure results between the groups. Plastic and total deformation was significantly higher in constructs in the DCS group than in those in the DFLP group. Total energy absorbed before construct failure was also significantly higher in the DFLP group than in the DCS group.Conclusions The DFLP construct proved stronger than the DCS in both axial stiffness and cyclic loading, but similar in torsional stiffness in biomechanical testing in a simulated A3 distal femoral fracture.     

Chronic lower extremity ischemia: a human model of ischemic tolerance.

BACKGROUND: Ischemic preconditioning (IPC) has been found in animals to have a protective effect against future ischemic injury to muscle tissue. Such injury is unavoidable during some surgical procedures. To determine whether chronic ischemia in the lower extremities would imitate IPC and reduce ischemic injury during vascular surgery, we designed a controlled clinical study. PATIENTS AND METHODS: Two groups of patients at a university-affiliated medical centre with chronic lower-extremity ischemia served as models of IPC: 6 patients awaiting femoral distal bypass (FDB) and 4 scheduled for aortobifemoral (ABF) bypass grafting for aortoiliac occlusive disease. Seven patients undergoing elective open repair of an infrarenal abdominal aortic aneurysm (AAA) were chosen as non-IPC controls. Three hematologic indicators of skeletal-muscle injury, lactate dehydrogenase (LDH), creatine kinase (CK) and myoglobin, were measured before placement of the proximal clamp, during surgical ischemia, immediately upon reperfusion, 15 minutes after and 1 hour after reperfusion, and during the first, second and third postoperative days. RESULTS: Baseline markers of skeletal-muscle injury were similar in all groups. In postreperfusion samples, concentrations of muscle-injury markers were significantly lower in the 2 PC groups than in the control group. For example, at day 2, LDH levels were increased by about 30% over baseline measures in the elective AAA (control) group, whereas levels in the FDB and ABF groups remained statistically unchanged from baseline. Myoglobin in controls had increased by 977%, but only by 160% in the FDB and 528% in the ABF groups. CK levels, in a similar trend, were 1432% higher in the control group and only 111% (FDB) and 1029% (ABF) in the study groups. Taken together, these data represent a significant level of protection. CONCLUSIONS: Patients with chronic lower-extremity ischemia suffered less severe ischemic injury after a period of acute ischemia than those with acute ischemia alone. Ischemic preconditioning is one proposed mechanism to help explain this protective effect.     

Do we need to obtain consent for penile shortening as a complication of treatment for organ‐confined prostate cancer?

What's known on the subject? and What does the study add? Penile shortening after total prostatectomy has been consistently reported, but most studies are small. BAUS has incorporated penile shortening into their patient information leaflets, but claims it is attributable to an anatomical alteration alone. No other organization even mentions penile shortening in their advice. Our study shows that a true, and at least partially reversible, penile shortening occurs in a significant proportion of patients after total prostatectomy. The cause of the shortening is largely physiological and interlinked with the processes leading to erectile dysfunction.

OBJECTIVE

• ? To establish an evidence base to guide consenting for treatment of organ‐confined prostate cancer with regard to penile shortening.

MATERIALS AND METHODS

• ? We performed literature searches using the EMBASE, MEDLINE, AHMED and PsycINFO databases up to October 2011, looking for articles relating to surgical treatment of prostate cancer and penile shortening and articles relating to radiotherapy for prostate cancer and penile shortening. We also looked at further references in the papers identified.

RESULTS

• ? We found 16 original papers and three review articles with measurements of penile shortening after total prostatectomy (TP).
• ? Penile shortening was generally considered in conjunction with erectile dysfunction (ED).
• ? Three further articles address psychological and consent issues.
• ? We found two articles regarding penile shortening after radiotherapy for prostate cancer.

CONCLUSIONS

• ? There is no doubt that TP leads to penile shortening in some patients, but the mechanism remains debatable.
• ? Given current evidence, it is likely that several factors contribute and early penile rehabilitation for ED, by any method, appears to positively influence the changes leading to penile shortening.
• ? We advise explicit mentioning of penile shortening in the consent process for TP and potentially also for radiotherapy for prostate cancer. We also advise early penile rehabilitation to improve the patient's own body image and, in turn, quality of life, even in patients who do not seek treatment specifically for ED. The choice of treatment method should be left to the patient.

     

Perioperative risk factors in patients with liver disease undergoing non-hepatic surgery

The patients with liver disease present for various surgical interventions. Surgery may lead to complications in a significant proportion of these patients. These complications may result in considerable morbidity and mortality. Preoperative assessment can predict survival to some extent in patients with liver disease undergoing surgical procedures. A review of literature suggests nature and the type of surgery in these patients determines the peri-operative morbidity and mortality. Optimization of premorbid factors may help to reduce perioperative mortality and morbidity. The purpose of this review is to discuss the effect of liver disease on perioperative outcome; to understand various risk scoring systems and their prognostic significance; to delineate different preoperative variables implicated in postoperative complications and morbidity; to establish the effect of nature and type of surgery on postoperative outcome in patients with liver disease and to discuss optimal anaesthesia strategy in patients with liver disease.     

Worldwide variability in deceased organ donation registries

The variability in deceased organ donation registries worldwide has received little attention. We considered all operating registries, where individual wishes about organ donation were recorded in a computerized database. We included registries which recorded an individual's decision to be a donor (donor registry), and registries which only recorded an individual's objection (non-donor registry). We collected information on 15 characteristics including history, design, use and number of registrants for 27 registries (68%). Most registries are nationally operated and government-owned. Registrations in five nations expire and require renewal. Some registries provide the option to make specific organ selections in the donation decision. Just over half of donor registries provide legally binding authorization to donation. In all national donor registries, except one, the proportion of adults (15+) registered is modest (<40%). These proportions can be even lower when only affirmative decisions are considered. One nation provides priority status on the transplant waiting list as an incentive to affirmative registration, while another nation makes registering a donation decision mandatory to obtain a driver's license. Registered objections in non-donor registries are rare (<0.5%). The variation in organ donor registries worldwide necessitates public discourse and quality improvement initiatives, to identify and support leading practices in registry use.     

Surgical management of bronchopleural fistula in pediatric empyema and necrotizing pneumonia: efficacy of the serratus anterior muscle digitation flap

PurposeSurgical management of bronchopleural (B-P) fistula associated with thoracic empyema and necrotizing pneumonia is challenging. We evaluated the treatment and outcome of early surgical intervention with limited decortication and insertion of a serratus anterior muscle digitation flap.MethodsA retrospective review during a 10-year period of children with empyema and B-P fistula secondary to necrotizing pneumonia was performed. During this period, 335 children with empyema were admitted, of which 20 developed a B-P fistula. All underwent a thoracotomy with insertion of a serratus anterior muscle digitation flap.ResultsPrethoracotomy chest computed tomographic scan was performed to define the pathologic characteristic. Streptococcus pneumoniae was identified by pus culture (n = 6) and by polymerase chain reaction (n = 4). The median postoperative time with pyrexia after surgical intervention was 2 days (range, 1-3 days). The median period of thoracostomy drain was 7 days (range, 5-15 days). Length of hospital stay was 21 days (range, 7-43 days). This parenchyma-preserving technique was able to control the B-P fistula successfully in all cases. No reintervention was necessary in any case. Respiratory symptoms and radiology improved in all children on follow-up, except for 3 who required oral antibiotics for subsequent chest infections.ConclusionEarly surgical intervention with insertion of a serratus anterior muscle digitation flap is effective and safe and avoids morbidity associated with conservative management and necrotic lung resection surgery.     

Nerve sparing can preserve orgasmic function in most men after robotic-assisted laparoscopic radical prostatectomy

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Orgasm has a major influence on patients’ satisfaction with the overall sexual experience, and alternations in orgasm are associated with significant reductions in emotional and physical satisfaction, which in turn may lead to sexual avoidance behaviour, disharmonious relationships and relationship breakdowns. Studies have found a reduction in orgasmic function after retropublic radical prostatectomy. While open radical prostatectomy inevitably damages some pelvic neuronal circuitry, which will thus impact on orgasmic responses, there is a paucity of data investigating the effect on robotic assisted radical prostatectomy on this. To our knowledge this study represents the largest analysis of orgasmic function in the robotic prostatectomy literature, and therefore would be of value to surgeons in counseling candidates for RALP about orgasmic outcomes. In our series, young men (age ≤60 years) and those who underwent bilateral nerve sparing approaches had a better recovery of their premorbid orgasmic function when compared to older men or men with no nerve sparing.

OBJECTIVE

• ? To investigate orgasmic outcomes in patients undergoing robotic‐assisted laparoscopic radical prostatectomy (RALP) and the effects of age and nerve sparing on these outcomes.

PATIENTS AND METHODS

• ? Between January 2005 and June 2007, 708 patients underwent RALP at our institution.
• ? We analysed postoperative potency and orgasmic outcomes in the 408 men, of the 708, who were potent, able to achieve orgasm preoperatively and available for follow‐up.

RESULTS

• ? Of men aged ≤60 years, 88.4% (198/224) were able to achieve orgasm postoperatively in comparison to 82.6% (152/184) of older men (P < 0.001).
• ? Of patients who received bilateral nerve sparing (BNS) during surgery, 273/301 (90.7%) were able to achieve orgasm postoperatively compared with 46/56 (82.1%) patients who received unilateral nerve sparing and 31/51 (60.8%) men who received non‐nerve‐sparing surgery (P < 0.001).
• ? In men ≤60 years who also underwent BNS, decreased sensation of orgasm was present in 3.2% of men, and postoperative orgasmic rates were significantly better than men ≤60 years who underwent unilateral or no nerve sparing (92.9% vs 83.3% vs 65.4%, respectively; P < 0.001).
• ? Potency rates were also significantly higher in men ≤60 years and in those who underwent BNS.

CONCLUSIONS

• ? Age and nerve sparing influence recovery of orgasm and erectile function after RALP.
• ? Men ≤60 years old and those who undergo BNS are most likely to maintain normal sexual function.

     

Oral bisphosphonate use in the elderly is not associated with acute kidney injury

Intravenous bisphosphonates can cause acute kidney injury; however, this risk was not found with oral bisphosphonates in randomized clinical trials with restrictive eligibility criteria. In order to provide complementary safety data, we studied the risk of acute kidney injury in a population-based cohort of 122,727 patients aged 66 years and older discharged from hospital following a new fragility fracture and no history of bisphosphonate use in the prior year. Bisphosphonate treatment was identified within 120 days after discharge and event rates were measured from 90 days of therapy initiation. The primary outcome was hospitalization with acute kidney injury with secondary outcomes of new nephrology consultation and, in a subset of patients with laboratory values, acute kidney injury was defined as an increase in serum creatinine. We identified 18,286 bisphosphonate users and 104,441 non-users with a mean age of 81 years. Of 5772 patients with laboratory values, 40% had chronic kidney disease (eGFR <60?ml/min per 1.73?m(2)). Overall, there was no statistically significant difference in the risk of acute kidney injury among bisphosphonate users compared to non-users (adjusted odds ratio 1.03), and no significant differences in other outcomes or in subgroups of patients with baseline chronic kidney disease. Thus, in this older population-based cohort, oral bisphosphonate use was not associated with acute kidney injury.     

Autosomal dominant progressive nephropathy with deafness: linkage to a new locus on chromosome 11q24

Focal segmental glomerulosclerosis (FSGS) and Alport syndrome (AS) are two major causes of end-stage renal disease (ESRD). A few families with autosomal dominant FSGS have been reported with linkage to chromosome 19q13 or 11q22, while AS is usually linked to mutations in type IV collagen (COL4) subunit genes. A phenotype resembling AS may also be seen with myosin heavy chain-9 (MYH9) gene mutations. This study ascertained a multigeneration family (CHP-177) with clinical aspects of both FSGS and AS where we identified a new locus for the trait. A genome-wide scan was performed with 400 markers, and fine mapping was performed for chromosome 11 markers. Data were analyzed by GENEHUNTER and VITESSE under various models. CHP-177 is a 39-member kindred residing near New Delhi, India, with seven affecteds and showed male-to-male transmission. Two members had ESRD. Renal biopsies showed both FSGS lesions and thin glomerular basement membranes. Five of the affecteds also had sensorineural deafness, which involved both low and high frequency in some members. The AS loci, i.e., COL4A3/COL4A4 and MYH9 (LOD scores: -6.1 and -4.3, respectively) and FSGS loci, on 19q13 and 11q22, were excluded from linkage. A significant evidence of linkage was observed for 11q24 region, with a multipoint LOD (z-score) of 3.2 for marker D11S4464 at theta = 0. The z-1 confidence interval for the linked region spans a genetic distance of 7 cM. This study thus reports an autosomal dominant nephropathy with features of both FSGS and AS in which linkage to currently known loci for such phenotypes was excluded and a new locus on 11q24 was identified. The findings suggest further locus heterogeneity for the autosomal dominant nephropathy phenotype.     

Evaluation of the microcirculation: Advances in cardiac magnetic resonance perfusion imaging

Conclusion  In this review we have examined the role of perfusion CMR for evaluating the integrity and function of the microcirculation. We have discussed the techniques for fully quantifying myocardial blood flow and the impact of different imaging parameters on quantification. Perfusion CMR not only identifies the presence of microvascular obstruction after a myocardial infarction but also relates it to patient prognosis. The ability to absolutely quantify myocardial blood flow improves the detection and evaluation of epicardial coronary disease and its risk factors. CMR perfusion imaging has proved to be an invaluable tool for understanding the integral role of the microcirculation in a variety of other cardiac disorders. Another advantage of perfusion CMR is the ability to measure differences in subendocardial and subepicardial blood flow. Newer techniques such as ASL and BOLD imaging promise to further improve the ability of CMR to assess the microcirculation without the use of exogenous contrast agents.