Citations

Background The GGGGCC-repeat expansion in C9orf72 is the most frequent mutation found in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Most of the studies on C9orf72 have relied on repeat-primed PCR (RP-PCR) methods for detection of the expansions. To investigate the inherent limitations of this technique, we compared methods and results of 14 laboratories. Methods The 14 laboratories genotyped DNA from 78 individuals (diagnosed with ALS or FTD) in a blinded fashion. Eleven laboratories used a combination of amplicon-length analysis and RP-PCR, whereas three laboratories used RP-PCR alone; Southern blotting techniques were used as a reference. Results Using PCR-based techniques, 5 of the 14 laboratories got results in full accordance with the Southern blotting results. Only 50 of the 78 DNA samples got the same genotype result in all 14 laboratories. There was a high degree of false positive and false negative results, and at least one sample could not be genotyped at all in 9 of the 14 laboratories. The mean sensitivity of a combination of amplicon-length analysis and RP-PCR was 95.0% (73.9–100%), and the mean specificity was 98.0% (87.5–100%). Overall, a sensitivity and specificity of more than 95% was observed in only seven laboratories. Conclusions Because of the wide range seen in genotyping results, we recommend using a combination of amplicon-length analysis and RP-PCR as a minimum in a research setting. We propose that Southern blotting techniques should be the gold standard, and be made obligatory in a clinical diagnostic setting.

SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided.

Objectives Growing evidence suggests that gender-blind assessment of exposure may introduce exposure misclassification, but few studies have characterised gender differences across occupations and industries. We pooled control responses to job-specific, industry-specific and exposure-specific questionnaires (modules) that asked detailed questions about work activities from three US population-based case–control studies to examine gender differences in work tasks and their frequencies. Methods We calculated the ratio of female-to-male controls that completed each module. For four job modules (assembly worker, machinist, health professional, janitor/cleaner) and for subgroups of jobs that completed those modules, we evaluated gender differences in task prevalence and frequency using χ2 and Mann–Whitney U tests, respectively. Results The 1360 female and 2245 male controls reported 6033 and 12 083 jobs, respectively. Gender differences in female:male module completion ratios were observed for 39 of 45 modules completed by ≥20 controls. Gender differences in task prevalence varied in direction and magnitude. For example, female janitors were significantly more likely to polish furniture (79% vs 44%), while male janitors were more likely to strip floors (73% vs 50%). Women usually reported more time spent on tasks than men. For example, the median hours per week spent degreasing for production workers in product manufacturing industries was 6.3 for women and 3.0 for men. Conclusions Observed gender differences may reflect actual differences in tasks performed or differences in recall, reporting or perception, all of which contribute to exposure misclassification and impact relative risk estimates. Our findings reinforce the need to capture subject-specific information on work tasks.

Abstract A recent randomized trial from the Finnish Degenerative Meniscal Lesion Study Group was published in the New England Journal of Medicine and attempted to determine the efficacy of partial meniscectomy without osteoarthritis. Patients were randomized to either arthroscopic partial meniscectomy or sham surgery. The authors concluded that the clinical outcomes after arthroscopic partial meniscectomy were no better than those after the sham surgical procedure. However, there are several important limitations of this trial that make it difficult to generalize to the 700,000 arthroscopic partial meniscectomies performed in the United States each year. In this small sample of 146 patients, patients with traumatic meniscal tears and locking symptoms—those most likely to benefit from a partial meniscectomy—were excluded. In addition, although patients with radiographic arthritis were excluded, most of the patients in the study had degenerative changes at the time of arthroscopy. Therefore it is difficult to determine whether the patients were symptomatic from their chondral degeneration or their degenerative meniscal tear. In our opinion this study does not change the role of surgery in current clinical practice. The primary indication for arthroscopic partial meniscectomy remains symptoms of well‐localized joint line pain with acute onset and mechanical symptoms such as catching or locking that have failed comprehensive nonoperative management.

AbstractPurposeTo identify patient concomitant injury and surgical characteristics associated with 6‐month excellent functional and isokinetic testing results following anterior cruciate ligament (ACL) reconstruction.MethodsPatients that underwent ACL reconstruction by a single surgeon had isokinetic and functional testing performed with excellent 6‐month outcome defined as greater than 85 % in isokinetic strength and 90 % in functional tests (excellent 6‐month group vs. delayed 6‐month group). Patient concomitant injury and surgical factors were then analysed in univariate and multivariate statistical models to assess which characteristics predicted the excellent 6‐month group.ResultsThe 224 patients included 93 males and 131 females, with median age of 22 (range 12–59) years, body mass index (BMI) of 25.4 (range 17–44), and median Tegner activity score of 6 (range 2–10). Fifty‐two patients (23 %) were included in the excellent 6‐month group, while 172 patients (77 %) were in the delayed 6‐month group. In univariate analysis, favourable factors with the excellent 6‐month outcome group were younger age (24 vs. 27; p = 0.01), lower BMI (24.5 vs. 26.2; p = 0.03), and minimal articular cartilage damage (71 vs. 56 %; p = 0.048). In multivariate analysis, a negative effect was observed for patients older than 30 years that had ACL reconstruction with autograft (p = 0.0004).ConclusionFactors significantly associated with excellent 6‐month functional and isokinetic test results following ACL reconstruction included younger age, lower BMI, and minimal cartilage degeneration. The use of allograft was associated with improved functional and strength testing after ACL reconstruction in patients over 30 years of age.Level of evidencePrognostic/therapeutic study, Level III.

AbstractPurposeCurrently, there is a paucity of literature regarding outcomes after isolated labral debridement. The purpose of this study was to (1) report the reoperation rate following isolated labral debridement, (2) report clinical and functional outcomes after labral debridement with a minimum 2‐year follow‐up and (3) identify risk factors for worse clinical and functional outcomes. It was hypothesized that inferior outcomes are associated with an increasing Tönnis grade and those with untreated femoral acetabular impingement (FAI).MethodsThe records of patients undergoing hip arthroscopy between 1998 and 2005 were reviewed. Patients with labral tears who underwent isolated arthroscopic labral debridement were identified. Kaplan–Meier estimate of failure (defined as subsequent surgery) was performed for all patients. Patients with minimum 2‐year follow‐up were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate analysis was then performed to assess which factors were associated with worse clinical and functional outcomes.ResultsFifty‐nine hips in 57 patients met our inclusion criteria (39 females, 18 males) with a mean age of 46 ± 14 years and mean follow‐up of 5 (range 2–14) years. Overall, 45 % of the hips failed for repeat surgery (20 %) or rating for hip function as abnormal or severely abnormal (25 %). Twelve hips (20 %) required subsequent surgical intervention at a mean 23 (range 6–60) months (7 total hip arthroplasties, 2 open revisions, 3 arthroscopic revisions). Of the remaining hips, mean MHHS was 83.4 ± 19.7, mean HOS ADL score was 83.8 ± 21.3 and mean HOS sport score was 70.6 ± 32.9, with 33 of 41 (75 %) reporting normal or nearly normal current level of function. Univariate analysis revealed that hips with untreated bony impingement (p = 0.01) or requiring concomitant chondroplasty (p = 0.03) had inferior clinical outcome scores.ConclusionsIsolated arthroscopic labral debridement for hip labral tears had 45 % combined poor results when strictly defining failure as repeat surgery or abnormal hip rating. Untreated FAI and concomitant chondroplasty were risk factors for inferior outcome. We recommend concomitant treatment for bony impingement lesions and preservation of the labrum whenever possible.Level of evidenceRetrospective case series, Level IV.

Abstract Purpose Intra‐articular (IA) hip cortisone injection is commonly performed as a therapeutic modality in patients with femoral acetabular impingement (FAI). To our knowledge, there is no published data evaluating the clinical benefit of these injections. The purpose of this study was to assess the efficacy of therapeutic IA cortisone injection in these patients. Methods At our institution, patients with FAI and labral tear prospectively recorded their numerical rating scale (NRS) pain scores pre‐injection, during post‐injection anaesthetic phase, and at 14 days post‐injection. From this cohort, all patients treated with guided IA cortisone injection, no radiographic evidence of arthritis (Tönnis grade 0 or 1) and pain relief during the anaesthetic phase of the IA injection were included. An absolute change of two points on the NRS score was considered the minimal amount of clinically significant pain relief. Pain scores were compared between the different types of steroid injected. Results Fifty‐four patients (35 females, 19 males) with a mean age of 32 ± 12 years were included. Average median pre‐injection NRS score was 7.0 (range 2.5–10.0), post‐injection anaesthetic phase was 1.0 (range 0.0–5.0), and 14 day post‐injection was 5.0 (range 0.0–10.0). As a group, NRS scores significantly diminished from post‐injection anaesthetic phase to 14 days post‐injection ( p < 0.001). At 14 days post‐injection, only 20 patients (37 %) and at 6 weeks, only 3 patients (6 %) reported a clinically significant decrease in pain. Average duration of pain relief was 9.8 days. There was no difference in pain reduction between steroid preparations. Conclusion In patients with symptomatic FAI and labral tear, intra‐articular cortisone injection has limited clinical benefit as a therapeutic modality. However, anaesthetic‐only IA injections for patients who may be candidates for hip arthroscopy can be a useful diagnostic tool. Level of evidence Therapeutic case series, Level IV.

The authors documented a low compliance with guidelines to screen for skin malignancy in a community-dwelling cohort of patients with newly diagnosed chronic lymphocytic leukemia.