Two-stage Group Research Articles

30. Retrospective comparative analysis of combined vs only posterior approach for treating severe scoliosis

BACKGROUND CONTEXT Studies comparing two-stage approach (first anterior then posterior) and only posterior approach for treating scoliosis are rather scarce, with shorter follow-up and lack of clinical data. PURPOSE The purpose of the retrospective study was to compare long-term clinical and radiological outcomes in comparable groups of patients when using different surgical approaches (two-stage and only posterior) for idiopathic scoliosis operations. STUDY DESIGN/SETTING A retrospective, one center, institutional review board approved study. PATIENT SAMPLE A total of 348 patients with idiopathic scoliosis were operated on using CD hybrid instrumentation with pedicle screw and hooks. Only patients with curvatures ≥61 ° were analyzed and divided in two groups: two-stage surgery (N=30) and one-stage surgery (N=46). OUTCOME MEASURES Not applicable. METHODS Comparisons between groups were made regarding the following variables: gender, age at surgery, follow-up duration, number of segments, duration of surgery, hospitalization time, and different radiological parameters. The anteroposterior (AP) and lateral standing radiographs were used to check for deformity; numbers of instrumented segments, curve flexibility (bending test), coronal and sagittal balance and rotation deformity. The coronal balance was measured as the distance between the C7 plumb line and the perpendicular line drawn from the center of S1. The sagittal balance was measured as shortest distance between the C7 plumb line and the posterior superior corner of the S1 body. For both coronal and sagittal measurements, balance was considered abnormal if the distance was greater than 2 cm. Measurement of vertebral rotation was done using the Nash-Moe method. All patients were invited in an outpatient clinic to fill out a short-form health survey (SF-36) and to make a control X-ray image of the whole spine. RESULTS No statistically significant difference was observed in correction between two-stage group (average correction 69%) and only posterior approach group (average correction 66%). However, there were statistically significant differences regarding hospitalization time, duration of the surgery and the number of instrumented segments. The SF-36 scores were similar and there were no statistically significant differences between different health dimensions among compared groups. The greatest differential found in mean scores was for energy and vitality. CONCLUSIONS Two-stage surgery has only a limited advantage in terms of postoperative correction angle compared to the posterior approach. Posterior instrumentation and correction is satisfactory, especially taking into account that the patient is subjected to only one surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

A comparison of short term complication rate between 44 two- and 385 one-stage septic exchange arthroplasties in chronic periprosthetic joint infections

BackgroundPeriprosthetic joint infection is a serious disease with severe consequences for the patient's life. It is not known whether one-stage or two-stage replacement arthroplasty is superior. So far, there have been no studies on short-term complications between both surgical procedures. Therefore, we performed a retrospective study aiming to determine: 1) Does two-stage septic exchange arthroplasty have a higher short-term complication rate than one-stage? 2) Is there a difference in length of hospital stay and the in-hospital mortality rate between two- and one-stage septic exchange arthroplasty? HypothesisTwo-stage septic exchange arthroplasty has a higher short-term complication rate than one-stage. Patients and methodsRetrospectively 429 patients who underwent a one- or two stage revision arthroplasty (288 hips and 141 knees) due to chronic PJI between January 2015 and December 2016 were recruited (one-stage: n=385, two-stage: n=44). Differences in postoperative complications, surgical therapy, ASA, Charlson Comorbidity Index (CCI), length of hospital, need for plastic surgery, pathogen, in-hospital morbidity and in-hospital mortality were compared using multiple logistic and Poisson regression. Regarding comorbidities, age, gender and BMI the groups were comparable. ResultsIt was 3.5 times more likely to suffer from a medical complication if a two stage septic exchange was performed (OR 3.465, (95% CI: 2.573–4.358) [p<0.01]). In medical complications the two-stage group showed significantly more events (two-stage: 9 of 44=20.5%; one-stage: 30 of 385=7.8% [p=0.013]). The one-stage group showed more (not significant) nerve palsies after hip septic exchange. There was no difference in mortality between the groups (two-stage: 1/44=2.3%; one-stage: 3/385=0.8% [p=0.882]), the overall mortality was 0.93%. The duration of hospital stay was 23.9±19 days for the one-stage and 42.2±17.7 days for the two-stage group (p<0.001). ConclusionWe found that it is more likely to develop a medical complication after two-stage septic revision arthroplasty. There was no difference in overall surgical complications between the two surgical approaches. We did not find a significant difference in short term mortality between the two techniques, although the mortality rate was slightly higher in the two-stage group. Level of evidenceIII, retrospective case control study.

Is the economic and social cost of one-stage bilateral hip resurfacing lower than two-stage procedures? Retrospective case-control study of 260 hips

BackgroundStudies on the economic impact of medical practices and estimates of intra- and extra-hospital costs have an important role in controlling healthcare spending. But few studies of this nature have been done for bilateral surgery in a single operative session. This led us to carry out a health economics study to determine whether (1) bilateral hip resurfacing arthroplasty (HRA) performed in one stage instead of two stages will reduce the health care expenditures (costs of hospitalization, medical leave, rehabilitation), (2) it is equally safe for the patient.Hypothesis One-stage bilateral HRA is less costly for the health care system than two-stage bilateral resurfacing. MethodsThis was a single-center, single-surgeon retrospective cohort study comparing patients who underwent bilateral HRA in one stage (53 cases) or in two stages (77 cases). We determined the intra-hospital costs based on the French National Cost Scales and the extra-hospital costs (medical leave and rehabilitation), perioperative data (blood loss, operation time, duration of narcotic analgesic use, medical and surgical complications) and the outcomes with a mean follow-up of 4.8 years [1.7–10.1]. ResultsThe total costs for the one-stage group (€16,840.94±7042.7) were significantly less than those of the two-stage group (€19,335.0±7296.9) (p=0.0101). The two groups were comparable except for the one-stage group having more primary hip osteoarthritis indications (72% (38/53)) than the two-stage group (49% (38/77)) (p=0.0111). The main differences between groups was the cost and duration of hospitalization, with cost of €10,546.06±2049.47 and average length of stay (ALS) of 9.83±2.19 days in the one-stage group and €13,569.49±2186.30, ALS=15.04±3.15 days in the two-stage group (p<0.0001). There was no significant difference in the length of medical leave: 67.15±50.36 (0–180) days for the one-stage group and 97.89±108.39 (0–730) days for the two-stage group (p=0.1933). ConclusionPerforming bilateral HRA during a single hospital stay results in lower health care expenditures than performing it during two separate hospital stays. Similar studies on other surgical procedures could help to promote the simultaneous nature of bilateral procedures and reset the current pricing, which is currently too low in the French health care system. Level of evidenceIII, Retrospective case-control study.

Two-stage hybrid Ivor-Lewis esophagectomy as surgical strategy to reduce postoperative morbidity for high-risk patients

BackgroundIvor-Lewis esophagectomy (ILE) is the standard surgical care for esophageal cancer patients but postoperative morbidity impairs quality of life and reduces long-term oncological outcome. Two-stage ILE separating the abdominal and thoracic phase into two distinct surgical procedures has proven to enhance microcirculation of the gastric conduit and therefore most likely reduces complications. However, two-stage ILE has not been evaluated systematically in selected groups of patients scheduled for this procedure. This investigation aims to demonstrate the feasibility of two-stage ILE in high-risk patients.Patients and methodsIn this retrospective analysis of data obtained from a prospective database, a consecutive series of 275 hybrid ILE (hILE) were included. Patients were divided into two groups based on one- or two-stage hILE. Postoperative complications were assessed according to ECCG (Esophageal Complication Consensus Group) criteria and compared using the Clavien–Dindo score. Indication for two-stage esophagectomy was classified as pre- or intraoperative decision.Results34 out of 275 patients (12.7%) underwent two-stage hILE. Patients of the two-stage group were significantly older. In 21 of 34 patients (61.8%) the decision for a two-stage procedure was made prior to esophagectomy, in 13 (38.2%) patients intraoperatively after completion of the laparoscopic gastric mobilization. The most frequent preoperative reason to select the two-stage procedure was a stenosis of the coeliac trunc and superior mesenteric artery (n = 10). The predominant cause for an intraoperative change of strategy was a laparoscopically diagnosed hepatic fibrosis/cirrhosis (n = 5).Overall morbidity and major’ complications (CD > IIIa) were comparable for both groups (11.7% in both groups). The overall anastomotic leak rate was 12.4% and was non-significant lower for the two-stage procedure.ConclusionTwo-stage hILE is a feasible concept to individualize the surgical treatment of patients with well-defined clinical risk factors for postoperative morbidity. It can also be applied after completion of the abdominal phase of IL esophagectomy without compromising the patient safety.

One-stage laparoscopic versus two-stage endoscopic followed by laparoscopic treatment for cholecystolithiasis complicated with choledocholithiasis

Objective To compare the clinical efficacy of one-stage laparoscopic cholecystectomy (LC) plus laparoscopic common bile duct exploration (LCBDE) with primary suture (PS) versus two-stage endoscopic retrograde cholangiopancreatography (ERCP)/endoscopic sphincterotomy(EST) followed by LC in treatment of cholecystolithiasis complicated with choledocholithiasis. Methods The clinical data of 171 patients with cholecystolithiasis complicated with choledocholithiasis, who underwent minimally invasive surgical treatment from January 2016 to December 2017, were retrospectively analyzed. Of these patients, 90 underwent one-stage LC+ LCBDE+ PS (the one-stage group), and 81 underwent two-stage ERCP/EST followed by LC (the two-stage group). The main clinical variables between the two groups of patients were compared. Results The surgical success rates (94.4% vs. 95.1%), residual stone rates (3.3% vs. 4.9%) and incidences of postoperative complications (6.7% vs.8.6%) showed no significant difference (all P>0.05) between the one-stage and two-stage groups. Compared with the two-stage group, the operative time was shorter (110.4 vs. 135.7 min), the length of postoperative hospital stay was shorter (3.3 vs. 7.1 d) and the total hospitalization cost was reduced (22 756.2 vs. 31 429.3 yuan) in the one-stage group. The incidence of long-term complications (2.2% vs.9.9%) in the one-stage group was also lower than that in the two-stage group (both P<0.05). Conclusions Both one-stage LC+ LCBDE+ PS and two-stage ERCP/EST+ LC are safe and effective in the treatment of cholecystolithiasis complicated with choledocholithiasis. One-stage LC+ LCBDE+ PS shows obvious advantages in hospitalization stay, hospitalization cost and in the preservation of function of the Oddi sphincter, and therefore should be the first choice in most cases. Key words: Cholecystolithiasis; Choledocholithiasis; Cholecystectomy, Laparoscopic; Cholangiopancreatography, endoscopic retrograde

Clinical significance of pretreatment with double J stent indwelling in the treatment of impacted Ureteral Calculi

Objective To analyze the clinical effects and safety of ureteroscopic lithotripsy (URL) in the treatment of impacted ureteral calculi by pretreatment with double-J stent indwelling. Methods Ninety-six patients with impacted ureteral calculi were enrolled in the study and were divided into one-stage group and two-stage group(pretreatment with double-J stent indwelling), with 48 patients in each group. The clinical effects and safety of the two groups were compared. Results The operative time and the hospital stay in two-stage group were significantly shorter than that in one-stage group, respectively (P<0.05). The success rate of stone clearance rate within 1 month in one-stage group were lower than that in two-stage group (P<0.05). One-stage group has a higher rate of complications compared with two-stage group(P<0.05). Conclusions Rigid combined with flexible ureteroscopic holmium laser lithotripsy is an effcacious and feasible approach for the treatment of impacted ureteral calculi, pretreatment with double-J stent indwelling can increase calculi clearance and improve efficacy and safety. Key words: Ureteral Calculi; Ureteroscopy; Cannula

Treatment of Middle East respiratory syndrome with a combination of lopinavir/ritonavir and interferon-\u03b21b (MIRACLE trial): statistical analysis plan for a recursive two-stage group sequential randomized controlled trial

The MIRACLE trial (MERS-CoV Infection tReated with A Combination of Lopinavir/ritonavir and intErferon-β1b) investigates the efficacy of a combination therapy of lopinavir/ritonavir and recombinant interferon-β1b provided with standard supportive care, compared to placebo provided with standard supportive care, in hospitalized patients with laboratory-confirmed MERS. The MIRACLE trial is designed as a recursive, two-stage, group sequential, multicenter, placebo-controlled, double-blind randomized controlled trial. The aim of this article is to describe the statistical analysis plan for the MIRACLE trial. The primary outcome is 90-day mortality. The primary analysis will follow the intention-to-treat principle. The MIRACLE trial is the first randomized controlled trial for MERS treatment.Trial registrationClinicalTrials.gov, NCT02845843. Registered on 27 July 2016.

Improving student assessment feedback in an introductory accounting course through two-stage collaborative assessment

Student feedback is an important part of the formative assessment process. Previous research shows that there is room for improvement in student feedback on accounting education. Various benefits, especially those associated with the development of certain pervasive skills through cooperative learning, have been established through research. The two-stage group examination offers students the opportunity to become active participants in the feedback process, while harvesting the benefits of teamwork. This study involving 24 students enrolled for an introductory accounting course evaluated the efficacy of the two-stage examination as an intervention to improve feedback. Students perceived that examination retakes in a team environment were helpful to establish where they made mistakes and showed them how they could improve their future performance. They could further establish how they performed compared to their peers. The examination retakes also helped to improve their understanding of the work and how they could improve their learning. The intervention was well received by students despite reports of free riding. This study adds to the limited body of research on two-stage exams in accounting education.

Learning hierarchically organized science categories: simultaneous instruction at the high and subtype levels

BackgroundMost science categories are hierarchically organized, with various high-level divisions comprising numerous subtypes. If we suppose that one’s goal is to teach students to classify at the high level, past research has provided mixed evidence about whether an effective strategy is to require simultaneous classification learning of the subtypes. This past research was limited, however, either because authentic science categories were not tested, or because the procedures did not allow participants to form strong associations between subtype-level and high-level category names. Here we investigate a two-stage response-training procedure in which participants provide both a high-level and subtype-level response on most trials, with feedback provided at both levels. The procedure is tested in experiments in which participants learn to classify large sets of rocks that are representative of those taught in geoscience classes.ResultsThe two-stage procedure yielded high-level classification performance that was as good as the performance of comparison groups who were trained solely at the high level. In addition, the two-stage group achieved far greater knowledge of the hierarchical structure of the categories than did the comparison controls.ConclusionIn settings in which students are tasked with learning high-level names for rock types that are commonly taught in geoscience classes, it is best for students to learn simultaneously at the high and subtype levels (using training techniques similar to the presently investigated one). Beyond providing insights into the nature of category learning and representation, these findings have practical significance for improving science education.

A time-truncated two-stage group acceptance sampling plan for odds exponential log-logistic distribution

In this article, two-stage group acceptance sampling plan is developed assuming that the lifetime of the test units follows odds exponential log-logistic distribution and the life test is terminated at a prefixed time. The acceptance of the lot mainly depends on the number of failures observed from each group either in the first or second stage of sampling. We examine the quality of organizations necessary for each of the two stages of the proposed lifetime distribution as to slash the average sample number under the satisfactory constraints of producer’s and consumer’s risk together. The proposed plan is compared with the single-stage group acceptance sampling plan as a special case in terms of the average sample number and the operating characteristics.

Effectiveness of two-stage versus one-stage injection in reducing discomfort during inferior alveolar nerve block in children

Background: Inferior alveolar nerve block (IANB) anesthesia is a painful procedure & many attempts are made to render the injection painless, especially in children. Aim: To assess discomfort expressed during modified two-stage IANB injection versus one-stage injection in 8-10 years old children. Subjects & Methods: Sixty children were randomly & equally allocated to either intervention group (two-stage) or control group (one-stage). For all patients, topical anesthesia gel was applied. Intervention group: A short needle was used for the initial piercing & deposition of the local anesthesia (LA), the needle was inserted for 4mm & 0.4ml of the solution was deposited, then withdrawn. After 5 min, a long needle (gauge 27) was advanced till the point of LA drug deposition & bone touching & the rest of the LA solution was deposited. Control group: A long needle was inserted, dropping 0.4 ml of the solution incrementally till the point of LA drug deposition & bone touching & the rest of the LA solution was deposited. The overall patients’ levels of discomfort were assessed using Face Legs Activity Cry Consolability scale (FLACC) & Facial Image Scale (FIS). Results were tabulated & statistically analyzed. Results: For FLACC scale, the post-anesthetic values recorded a median=1 (range=0-3) in two-stages group, & a median=2 (range=0-4) in one-stage group; with statistically significant difference between them (p=0.00). For FIS, a median=2 (range=1-4) in the two-stage group & a median = 3 (range=1-5) in one-stage group; the difference between groups was statistically significant (p=0.017). Conclusion: The two-stage IANB injection technique is a simple & an effective method of reducing the overall discomfort in children.

Early Experience with Variant Two-Stage Approach in Surgical Management of Inflammatory Bowel Disease Colitis in the Pediatric Population.

Introduction: Multistaged surgical management of inflammatory bowel disease (IBD), culminating in ileal pouch-anal anastomosis (IPAA), can provide cure for refractory IBD symptoms while maintaining fecal continence. Surgical approaches to IPAA historically included a three-stage approach done by subtotal colectomy (STC) followed by IPAA with diversion. Recently, a variant two-stage approach without diversion at IPAA has become increasingly utilized, yet evidence of the efficacy of this approach is limited. Methods: Retrospective review of patients aged 5-21 years who underwent initial STC, followed by a total proctocolectomy with IPAA +/- diversion for medically refractory IBD from January 2010 to August 2018 (n = 25). Results: Majority of IPAA procedures were done laparoscopically (88.5%). Thirteen patients (52%) underwent two-stage variant IPAA. There were no differences in readmission rates (66.7% versus 53.8%, P = .5) or reoperation rates (50% versus 30.8%, P = .3) between groups. Forty percent of patients experienced a complication after IPAA. Complication rates were similar between two-stage and three-stage IPAA groups (38.5% versus 50%, P = .33). Complications within the two-stage group included anastomotic leak, pouchitis, wound infection, anastomotic stricture, and incarcerated hernia. Complications within the three-stage group included bloody ostomy output, dehydration, anastomotic stricture, small bowel obstruction, and pouch volvulus. Conclusions: Treatment of refractory IBD in children remains challenging, but STC followed by IPAA is an approach that provides symptom relief and preserves continence. Complication rates remained unchanged regardless of whether IPAA was conducted with or without diversion, demonstrating that the two-stage variant approach is a safe and feasible treatment that may reduce subsequent anesthesia exposure and trips to the operating room.

Odds ratio based two-stage group sequential analysis for two-treatment two-period crossover trials

We consider a two-treatment and two-period crossover design where the treatment responses are binary. The outcome from each patient under such trial can be represented by a two-component vector which follows a bivariate binomial distribution. We develop a two-stage group sequential test procedure for equivalence based on the estimates of odds ratio. Various error spending functions are studied in this context. Simulation studies are carried out. An illustration with some real data example is also given.

One- versus two-stage transposed brachiobasilic arteriovenous fistulae: A review of the current state of the art.

In the absence of suitable cephalic vein, the brachiobasilic vein complex represents the best option for arteriovenous access. However, the basilic vein is too deep to cannulate and requires transposition to be accessible. Transposition can be performed during fistula creation (single-stage BBTx) or at a second operation after initial fistula creation (two-stage brachiobasilic transposition (BBTx)). The best approach is unknown. A PubMed search using "Basilic vein transposition" as the primary search term was performed to identify articles addressing this controversy. Meta-analysis was then performed using those papers that provided the inspected data points with student's t-test used to compare maturation and patency rates between the groups. A total of 37 manuscripts were judged of adequate quality for analysis. Based on the available data, overall maturation rates, 1-year primary patency rates, and overall complication rates seem to be equivalent between single- and two-stage BBTx, while 1-year secondary patency is greater in the two-stage group (79% vs 85%). A large prospective randomized clinical trial with clear definitions of maturity, patency, and complications is needed to definitively answer the question of whether one strategy is better than the other.

Sow and piglet behaviour in group lactation housing from 7 or 14 days post-partum

Under natural conditions, sows and piglets abandon the nest between 7 and 14 days postpartum and re-join the group. If given the choice, commercially housed sows begin to nurse piglets communally around this time. The best age at which to group sows and their litters in two-stage group lactation systems has not been determined. A total of 112 multiparous sows and their litters were allocated to three lactation housing treatments over four time replicates. All sows farrowed in standard farrowing crates. Group lactation (GL) sows were transferred to group pens (one pen of 5 sows at 8.4 m2/sow and one pen of 7 sows at 8.1 m2/sow, per GL treatment and replicate) with their litters at 7 (GL7; n = 48 sow and litter units) or 14 (GL14; n = 48 sow and litter units) days postpartum until weaning. Farrowing crate (FC; n = 16 sow and litter units) sows and their litters remained within FC in single litters until weaning. In each replicate, two focal sows per GL pen (one high and one low parity) were video recorded for 1 h post-mixing. The GL focal sows, along with 4 FC sows (two high and two low parity) and 2 focal piglets per focal sow (one average sized male and one average sized female), were also recorded from 0700 to 1700 on the day after mixing and 2 days before weaning. Data gathered continuously from video records included sow aggressive and nursing behaviours while sow and piglet time-budgets were observed using point sampling at 5-min intervals. Social affiliative nosing was more frequent between GL14 than GL7 sows (P = 0.01), but aggression did not differ (P > 0.05). There were no other effects of litter age at mixing on sow or piglet behaviour (P > 0.05). Compared to FC sows, GL sows were more active (P < 0.001), explorative (P < 0.001) and interactive with piglets (P = 0.03). However, GL sows had fewer successful nursings (P = 0.002) and terminated more nursings (P = 0.001) than FC sows. The time GL piglets spent suckling (P < 0.001) and nosing (P = 0.001) sows other than their dam increased over time. Compared to FC piglets, GL piglets spent more time in the creep (P = 0.05), active when outside of the creep (P = 0.04) and investigating the pen (P = 0.02), and less time manipulating other piglets (P = 0.005). There do not appear to be behavioural differences in sows and piglets between mixing into GL at 7 or 14 days postpartum. While GL allows for the expression of maternal and exploratory behaviours, these benefits come at the cost of disrupted nursing behaviour and cross-suckling.

One-stage versus two-stage prosthesis replacement for prosthetic knee infections

IntroductionPeriprosthetic knee infection is a severe complication. Confirmed criteria are lacking to choose between one-stage or two-stage prosthesis replacement to treat the infection. The one-stage replacement could lead to a satisfactory control of the infection and to better functional results. MethodRetrospective study conducted between January 1, 2009 and December 31, 2014. The objectives of this study were to compare the infection outcome and functional results between the one-stage and two-stage replacement procedures. Functional results were evaluated using the IKS score, KOOS score, and SF-12 quality of life score. ResultsForty-one patients underwent a two-stage replacement procedure and 21 patients a one-stage replacement. The average follow-up was 22 months after surgery. The infection was cured in 78% of patients who underwent a two-stage replacement and 90% of patients who underwent a one-stage replacement (P=0.3). The flexion range of motion was significantly better in the one-stage group than in the two-stage group (P=0.04). Results of the IKS score and of the KOOS score were better in the one-stage group. No difference was observed for the SF-12 score. ConclusionThe one-stage replacement procedure for periprosthetic knee infection was associated with a similar healing frequency as the two-stage replacement procedure, and with better knee function.

High incidence of early periprosthetic joint infection following total hip arthroplasty with concomitant or previous hardware removal

Hardware removal preceding total hip arthroplasty may increase the risk of prosthetic joint infection (PJI). Whether hardware removal and total hip arthroplasty (THA) should be performed in a single- or two-stage procedure remains controversial. In this comparative retrospective study, the incidence of PJI following either single- or two-stage THA with hardware removal was assessed in a consecutive series. All patients that underwent THA preceded by hardware removal from January 2006 until March 2018 were retrospectively reviewed and checked for the occurrence of early PJI. Recognized risk factors for PJI at the time of surgery were evaluated and the incidence of early PJI was compared between one- and two-stage THA regarding hardware removal. 145 patients underwent THA and hardware removal (52 two-stage surgery and 93 single-stage surgery). There were no significant differences between both groups regarding pre-operative hemoglobulin levels, time interval between internal fixation and THA, antibiotic-loaded-cement use, BMI and ASA classification. Overall the incidence of early PJI was 6.9%. The incidence of PJI was 8.6% in the single-stage group versus 3.8% in the two-stage group (P = 0.234). Irrespective of single- or two-stage procedures, a high incidence of PJI was encountered. Despite non-significance, a trend towards a higher proportion of patients developing PJI after single-stage surgery was encountered. We recommend a two-stage surgical procedure regarding hardware removal and THA in patients that are expected to tolerate this surgical strategy. When considering a one-stage procedure, it should be preceded by a thorough pre-operative workup including joint aspiration and serum determination of inflammatory parameters. Multiple tissue samples should be obtained during hardware removal in either one- or two-stage procedures since the risk for development of PJI is relevant.

Comparison of one-stage versus two-stage procedure for the management of patients with rotator cuff tear and concomitant shoulder stiffness

BackgroundTo compare the clinical outcomes of one-stage and two-stage procedures for the management of patients with rotator cuff tear and concomitant shoulder stiffness.MethodsFrom December 2013 to June 2016, we recruited 42 consecutive patients with rotator cuff tear and concomitant shoulder stiffness. Twenty-two patients underwent a one-stage procedure, including arthroscopic capsule release and concomitant rotator cuff repair, within 2 weeks of the diagnosis. For the remaining twenty patients, conservative treatment for the recovery of range of motion (ROM) was initially performed before arthroscopic rotator cuff repair. The ROM, visual analogue scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, and satisfaction rate were assessed preoperatively; 3, 6, 12, and 24 months after surgery; and at final follow-up.ResultsThe mean follow-up period was 26.3 months (range, 24–33 months). No significant difference was noted in preoperative demographic data (age, sex, dominant/non-dominant, diabetes mellitus, thyroid disease, and duration of symptoms) between the two groups (P = 0.165, P = 0.580, P = 0.662, P = 0.716, P = 0.231, and P = 0.152, respectively). After treatment, all patients exhibited significant improvement in ROM and functional scores (P = 0.001 and P = 0.001, respectively). At 3 months postoperatively, the two-stage group exhibited significantly improved forward flexion and internal rotation compared with the one-stage group (P = 0.001 and P = 0.038, respectively). No significant difference in ROM was noted between the two groups at 6, 12, 24 months postoperatively and the final follow-up. In addition, no significant differences in VAS, ASES, Constant-Murley score and satisfaction rate were noted between the two groups at final follow-up (P = 0.319, P = 0.529, P = 0.711, and P = 0.085, respectively).ConclusionIn the treatment of rotator cuff tear with concomitant stiffness, although the recovery of ROM took longer in patients who underwent the one-stage procedure, satisfactory results at final follow-up can be achieved using either the one-stage procedure or two-stage procedure.Study designCase-control study.

Group lactation from 7 or 14 days of age reduces piglet aggression at weaning compared to farrowing crate housing

Early life experiences can affect social behaviour in later life, but opportunities for socio-behavioural development are often overlooked in current husbandry practices. This experiment investigated the effects of rearing piglets in two-stage group lactation (GL) system from 7 or 14 days of age on piglet aggression at weaning. Three lactation housing treatments were applied to a total of 198 piglets from 30 litters of multiparous sows. All dams farrowed in standard farrowing crates (FCs). Group lactation litters were transferred with their dam at 7 (GL7) or 14 days (GL14) postpartum to GL pens (one pen of five sows at 8.4 m2/sow and one pen of seven sows at 8.1 m2/sow, per GL treatment). Farrowing crate litters remained with their dam in a single litter until weaning. At weaning, 10 to 14 piglets from two unfamiliar litters from the same housing treatment were mixed into pens (n=5 pens/treatment) and their behaviour was continuously recorded for 3.5 h. For each pen, the frequency of aggressive bouts (reciprocal and non-reciprocal aggression lasting <5 s), the frequency and duration of fights (reciprocal aggression lasting ⩾5 s) and bullying events (non-reciprocal aggression lasting ⩾5 s) were recorded, along with whether interactions involved familiar or unfamiliar piglets. Aggressive bouts delivered by FC piglets were approximately 1.5 and 3.0 times more frequent than that delivered by GL7 and GL14 piglets, respectively (40.5, 16.7 and 9.9 bouts/pig, respectively; P<0.05). Fighting was more frequent (1.6, 0.3 and 0.4 fights/pig, respectively; P<0.001) and fights were longer (83, 15 and 32 s fight/pig, respectively; P<0.001) between FC piglets than between GL7 or GL14 piglets. Bullying did not differ between housing treatments (P>0.05). GL7 and GL14 piglets engaged in a similar number of fights with unfamiliar as familiar piglets, but FC piglets had almost three times as many fights with unfamiliar than with familiar piglets (P<0.05). This experiment confirms the benefits of GL housing for pig social development. Further investigation is required to determine whether mixing before 14 days postpartum has implications for other indicators of animal welfare and productivity in a two-stage GL housing system.

Two-stage cleft palate closure by our treatment algorithm in complete unilateral cleft lip and palate: Results of maxillary growth at 6 years of age

ObjectiveWe evaluated maxillary growth outcomes of our modification of a two-stage palatoplasty algorithm (the Zurich University protocol) for the treatment of complete unilateral cleft lip, alveolus, and palate (UCLP) that allows for maxillary growth by delaying alveolar and hard palate closure with bone grafting until age 8 years or older. MethodsWe obtained measurements from lateral cephalograms taken at age 6 years for 46 consecutive patients and compared them between the two-stage group and children without UCLP (non-cleft group) and children with UCLP historically treated with push-back palatoplasty. Values related to facial growth were compared between the three groups and by sex. Profilograms were compared between the two-stage and non-cleft groups. ResultsSella-nasion distance, sella-nasion-point A angle, and sella-nasion-point B angle were significantly smaller in the two-stage group than in the non-cleft group among boys but were not significantly different among girls. Profilograms showed that these smaller values reflected a smaller skull size. However, in the two-stage group, the point A-nasion-point B angle (∠ANB) was 2 standard deviations (SDs) less than the mean in 3 patients (6.5%) and 1 SD less in 10 patients (21.7%), reflecting poor maxilla-mandibular relationships. Compared with the push-back group, the two-stage group showed better maxillary growth in all measured values. ConclusionsPostoperative maxillary growth was acceptable and better with two-stage palatoplasty than with push-back palatoplasty. However, about 30% of two-stage patients had worse ∠ANB, indicating the need for careful follow-up and analysis of maxillary growth when the child reaches adulthood.