Large Diameter Metal on Metal Articulations. Comparison of Total Hip Arthroplasty and Hip Resurfacing Arthroplasty

The use of large diameter metal bearing total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) increased in popularity in the last decade. More recent literature has highlighted the effect of head size in patient outcomes. Data was obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOA-NJRR) to evaluate the Birmingham (MoM) bearing surface when used with THA and HRA. There is no difference in the overall rate of revision between the THA and HRA but head size has a significant effect on revision rate. The data show that small diameter metal bearings in HRA (below 50 mm) have a higher rate of revision than large diameter metal bearings in HRA (equal to and above 50 mm) (P < .001). Conversely the large diameter metal bearings in THA have a higher rate of revision than the small diameter metal bearings in THA (P = .027). The revision rate for large diameter HRA compared to small diameter THA is not significantly different P = .670. We recommend caution when choosing either a large diameter (≥ 50 mm) metal on metal THA or small diameter (< 50 mm) HRA.     

Exeter Short Stems Compared With Standard Length Exeter Stems : Experience From the Australian Orthopaedic Association National Joint Replacement Registry

The standard Exeter stem has a length of 150 mm with offsets 37.5 to 56 mm. Shorter stems of lengths 95, 115 and 125 mm with offsets 35.5 mm or less are available for patients with smaller femurs. Concern has been raised regarding the behavior of the smaller implants. This paper analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry comparing survivorship of stems of offset 35.5 mm or less with the standard stems of 37.5 mm offset or greater. At 7 years, there was no significant difference in the cumulative percent revision rate in the short stems (3.4%, 95% CI 2.4-4.8%) compared with the standard length stems (3.5%, 95% CI 3.3-3.8%) despite its use in a greater proportion of potentially more difficult developmental dysplasia of the hip cases.     

The Prevalence and the Characteristics of Tuberculosis Patients Undergoing Chronic Dialysis Treatment: Experience of a Dialysis Center in Southeast Turkey

Tuberculosis remains a significant health problem for patients receiving chronic dialysis. The purpose of this study was to evaluate the prevalence, clinical characteristics, and outcomes of tuberculosis among patients with end-stage renal failure (ESRF) undergoing chronic hemodialysis and continuous ambulatory peritoneal dialysis. Between 1999 and 2006, we diagnosed 21 active tuberculosis patients among a total of 674-dialysis patient in our dialysis center (582 patients on hemodialysis and 92 patients on continuous ambulatory peritoneal dialysis program). Fourteen patients developed extrapulmonary tuberculosis (generally tuberculous lymphadenitis, n = 8) and seven patients developed pulmonary tuberculosis. All patients who developed tuberculosis after starting dialysis had low creatinine clearances and, in general, anemia and hypoalbuminemia. Three of patients greater than 40 years died. In conclusion, tuberculous lymphadenitis was the most frequent form of extrapulmonary tuberculosis in our dialysis population. If no cause is found despite extensive investigations in an end stage renal failure case with fever, loss of weight, and/or atypical lymphadenopathy, the physician should consider the possibility of tuberculosis. Finally, it was considered that ESRF is associated with depressed immune system and elevated risk of tuberculosis; thus, in this population, clinicians must evaluate patients carefully.     

Patients with Lynch Syndrome Mismatch Repair Gene Mutations Are at Higher Risk for Not Only Upper Tract Urothelial Cancer but Also Bladder Cancer

Background

Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer, is caused by mutations in mismatch repair (MMR) genes. An increased risk for upper tract urothelial carcinoma (UTUC) has been described in this population; however, data regarding the risk for bladder cancer (BCa) are sparse.

Objective

To assess the risk of BCa in MMR mutation carriers and suggest screening and management recommendations.

Design, setting, and participants

Cancer data from 1980 to 2007 were obtained from the Familial Gastrointestinal Cancer Registry in Toronto for 321 persons with known MMR mutations: mutL homolog 1, colon cancer, nonpolyposis type 2 (E. coli) (MLH1); mutS homolog 2, colon cancer, nonpolyposis type 1 (E. coli) (MSH2); mutS homolog 6 (E. coli) (MSH6); and PMS2 postmeiotic segregation increased 2 (S. cerevisiae) (PMS2).

Outcome measurements and statistical analysis

Standardized incidence ratios from the Ontario Cancer Registry, using the Surveillance Epidemiology and End Results public database, were used to compare cancer risk in patients with MMR mutations with the Canadian population. Microsatellite instability analysis and immunohistochemistry (IHC) of the MMR proteins were also performed and the results compared with matched sporadic bladder tumors.

Results and limitations

Eleven of 177 patients with MSH2 mutations (6.21%, p < 0.001 compared with the Canadian population) were found to have BCa, compared with 3 of 129 patients with MLH1 mutations (2.32%, p > 0.05). Of these 11 tumors, 81.8% lacked expression of MSH2 on IHC, compared with the matched sporadic cases, which all displayed normal expression of MSH2 and MLH1. The incidence of UTUC among MSH2 carriers was 3.95% (p < 0.001), and all tumors were found to be deficient in MSH2 expression on IHC. Mutations in the intron 5 splice site and exon 7 of the MSH2 gene increased the risk of urothelial cancer. Limitations include possible inflated risk estimates due to ascertainment bias.

Conclusions

LS patients with MSH2 mutations are at an increased risk for not only UTUC but also BCa and could be offered appropriate screening.     

Omental patch repair effectively treats perforated marginal ulcer following Roux-en-Y gastric bypass

Background

Marginal ulcer formation remains a significant complication of Roux-en-Y gastric bypass (RYGB). Up to 1 % of all RYGB patients will develop free perforation of a marginal ulcer. Classically, this complication has required anastomotic revision; however, this approach is associated with significant morbidity. Several small series have suggested that omental patch repair may be effective. The aim of this study was to examine the management of perforated marginal ulcers following RYGB.

Methods

All patients who underwent operative intervention for perforated ulcers between 2003 and 2011 were reviewed. Those with a history of RYGB with perforation of a marginal ulcer were included in the analysis. Data collected included operative approach, operative time, blood loss, length of hospital stay, complications, smoking history, and steroid or NSAID use.

Results

From January 2003 to December 2011, a total of 1,760 patients underwent RYGB at our institution. Eighteen (0.85 %) developed perforation of a marginal ulcer. Three patients’ original procedure was performed at another institution. Eight patients (44 %) had at least one risk factor for ulcer formation. Treatment included omental patch repair (laparoscopic, n = 7; open, n = 9) or anastomotic revision (n = 2). Compared to anastomotic revision, omental patch repair had shorter OR time (101 ± 57 vs. 138 ± 2 min), decreased estimated blood loss (70 ± 72 vs. 250 ± 71 mL), and shorter total length of stay (5.6 ± 1.4 vs. 11.0 ± 5.7 days).

Conclusions

Perforated marginal ulcer represents a significant complication of RYGB. Patients should be educated to reduce risk factors for perforation, as prolonged proton pump inhibitor therapy may not prevent this complication in a patient with even just one risk factor. In our sample population we found laparoscopic or open omental patch repair to be a safe and effective treatment for this condition and it was associated with decreased operative time, blood loss, and length of stay.     

Dalteparin Vs Low-Dose Unfractionated Heparin for Prophylaxis Against Clinically Evident Venous Thromboembolism in Acute Traumatic Spinal Cord Injury: A Retrospective Cohort Study

Background: When venous thromboembolism (VTE) includes deep-vein thrombosis (DVT) and pulmonary embolism (PE), patients with acute traumatic spinal cord injury (SCI) have the highest incidence of VTE among all hospitalized groups, with PE the third most common cause of death. Although low-molecular-weight heparin (LMWH) outperforms low-dose unfractionated heparin (LDUH) in other patient populations, the evidence in SCI remains less robust.

Objective: To determine whether the efficacy for LMWH shown in previous SCI surveillance studies (eg, routine Doppler ultrasound) would translate into real-world effectiveness in which only clinically evident VTE is investigated (ie, after symptoms or signs present).

Methods: A retrospective cohort study was conducted of 90 patients receiving LMWH dalteparin (5,000 U daily) or LDUH (5,000 U twice daily) for VTE prophylaxis after acute traumatic SCI. The incidence of radiographically confirmed VTE was primarily analyzed, and secondary outcomes included complications of bleeding and heparin-induced thrombocytopenia.

Results: There was no statistically significant association (p = 0.7054) between the incidence of VTE (7.78% overall) and the type of prophylaxis received (LDUH 3/47 vs dalteparin 4/43). There was no significant differences in complications, location of VTE, and incidence of fatal PE. Paraplegia (as opposed to tetraplegia) was the only risk factor identified for VTE.

Conclusions: There continues to be an absence of definitive evidence for dalteparin (or other LMWH) over LDUH as the choice for VTE prophylaxis in patients with SCI. Novel approaches to VTE prophylaxis are urgently required for this population, whose risk of fatal PE has not decreased over the last 25 years.     

Predictors of a difficult intubation in the bariatric patient: does preoperative body mass index matter?

BackgroundThe incidence of difficult intubations in morbidly obese patients has been reported to be 12–20%; however, no well-established predictors of a difficult intubation exist for this patient population. Our objective was to evaluate the factors associated with a difficult intubation in morbidly obese patients undergoing laparoscopic Roux-en-Y gastric bypass at an integrated multispecialty health system with a 325-bed community teaching hospital serving 19 counties.MethodsThe anesthetic records of patients undergoing LRYGB from 2001 to 2010 were reviewed. Difficult intubations were defined as direct laryngoscopy graded ≥1 on a 0–2 difficulty scale and unplanned fiberoptic intubations. Statistical analysis included chi-square, univariate, and multivariate logistic regression.ResultsA total of 915 consecutive patients underwent LRYGB during the study period. Of these, 3 patients were excluded because of incomplete data. Of the 912 included patients, 25 (2.7%) underwent planned fiberoptic intubation, 830 (91%) had an uneventful intubation, and 57 (6.3%) had a difficult intubation. Difficult intubations were more common in men than in women (11% versus 6%, P = .027). Difficult intubations were not associated with an increasing preoperative body mass index (P = .073), the presence of obstructive sleep apnea (P = .784), or the presence of gastroesophageal reflux disease (P = .335). Multivariate predictors of a difficult intubation were Mallampati class 4 (odds ratio [OR] 2.76, P = .035), abnormal thyromental distance (OR 4.39, P = .001), restricted jaw mobility (OR 3.26, P = .018), and a history of a difficult intubation (OR 4.17, P = .002).ConclusionsAn increased Mallampati class, abnormal thyromental distance, restricted jaw mobility, and a history of difficult intubations were independent predictors of a difficult intubation. An increasing body mass index did not predict for a difficult intubation.