Expansile gas kinetics for pneumatic retinopexy

PURPOSE

To study the behaviour of expansile intravitreal gases and air used in treating rhegmatogenous retinal detachment.

METHODS

A validated mathematical model of gas expansion and absorption in human eyes was used to simulate the effect of varying volumes of pure air, SF6, C2F6 and C3F8 injected into the vitreous cavity. Variation in axial length was accounted for by using three different vitreous cavity volumes to represent hypermetropic, emmetropic and myopic eyes.

RESULTS

The time course of varying volumes of pure air and fluorinated gases injected into the vitreous cavity were tabulated, with calculated parameters including volume of gas, percentage gas fills and corresponding retinal contact angles at different time points.

CONCLUSION

We produced a comprehensive compilation of expansive gas kinetics aiming to facilitate surgeon selection of the most suitable choice of gas and volume to use, tailored to an individual patient's clinical need.

Conventional versus miniaturized cardiopulmonary bypass: A systematic review and meta-analysis

Objective

A meta-analysis of randomized controlled trials was performed to compare the effects of miniaturized extracorporeal circulation (MECC) and conventional extracorporeal circulation (CECC) on morbidity and mortality rates after cardiac surgery.

Methods

A comprehensive literature search was conducted using Ovid, PubMed, Medline, EMBASE, and the Cochrane databases. Randomized controlled trials from the year 2000 with n > 40 patients were considered. Key search terms included variations of “mini,” “cardiopulmonary,” “bypass,” “extracorporeal,” “perfusion,” and “circuit.” Studies were assessed for bias using the Cochrane Risk of Bias tool. The primary outcomes were postoperative mortality and stroke. Secondary outcomes included arrhythmia, myocardial infarction, renal failure, blood loss, and a composite outcome comprised of mortality, stroke, myocardial infarction and renal failure. Duration of intensive care unit, and hospital stay was also recorded.

Results

The 42 studies eligible for this study included a total of 2154 patients who underwent CECC and 2196 patients who underwent MECC. There were no significant differences in any preoperative or demographic characteristics. Compared with CECC, MECC did not reduce the incidence of mortality, stroke, myocardial infarction, and renal failure but did significantly decrease the composite of these outcomes (odds ratio, 0.64; 95% confidence interval [CI], 0.50-0.81; P = .0002). MECC was also associated with reductions in arrhythmia (odds ratio, 0.67; 95% CI, 0.54-0.83; P = .0003), blood loss (mean difference [MD], –96.37 mL; 95% CI, –152.70 to –40.05 mL; P = .0008), hospital stay (MD, –0.70 days; 95% CI, –1.21 to –0.20 days; P = .006), and intensive care unit stay (MD, –2.27 hours; 95% CI, –3.03 to –1.50 hours; P < .001).

Conclusions

MECC demonstrates clinical benefits compared with CECC. Further studies are required to perform a cost–utility analysis and to assess the long-term outcomes of MECC. These should use standardized definitions of endpoints such as mortality and renal failure to reduce inconsistency in outcome reporting.

889 Management of Paediatric Appendicitis During the First Wave of COVID-19: Comparison of Our Centre to National Practice

Aim

Our hospital took part in a multi-centre prospective cohort study “the CASCADE study” investigating the management and early outcomes of children with appendicitis in the UK and Ireland during the first wave of the COVID-19 pandemic (1). The aim of this study was to compare our local outcomes to those at a national level.

Method

This was a prospective cohort study with data collected from 01/04/2020 to 31/05/2020. Primary outcome was treatment strategy for appendicitis. Secondary outcomes were duration of symptoms, ultrasound findings, rate of simple vs perforated appendicitis and complications.

Results

Overall, only a minority (2/24 [8%]) were initially treated non-operatively, with both proceeding to appendicectomy due to pain. Remaining children (24/26 [92%]) were primarily treated with appendicectomy. All were performed laparoscopically with no conversions to open. Ultrasound was performed for most children (23/26 [88%]) which accurately identified appendicitis (22/23 [95%]) and negative appendicectomy rate of zero. Rates of complex appendicitis were not higher than expected (10/26 [38%]) but had a longer duration of symptoms (median 66.0h [IQR21.5] vs 30.0h [27.2], p = 0.008) and more complications (4 vs 1). Post-operative length of stay was significantly shorter for simple appendicitis than complicated (median 1.0d [IQR0.0] vs 4.0 [IQR2.8], p = 0.001).

Conclusions

Practice in our centre contrasts with the CASCADE study's National findings where 39% were treated non-operatively, only 48% of appendicectomies were performed laparoscopically, only 53% of children had diagnostic imaging and negative appendicectomy rate was 4.5%. Rates of complications for simple and complex appendicitis were similar, but post-operative length of stay shorter in our centre.

Proton beam therapy in rectal cancer: A systematic review and meta-analysis

INTRODUCTION

Locally advanced rectal cancer is often treated with neoadjuvant chemoradiotherapy and surgery. Radiotherapy carries significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) has demonstrated to be effective in other cancers, delivering equivalent dosimetric radiation but with the benefit of improved sparing of OAR. This review compares dosimetric irradiation of OAR and oncological outcomes for PBT versus conventional photon-based radiotherapy in locally advanced rectal cancer.

METHODS

An electronic literature search was performed for studies with comparative cohorts receiving proton beam therapy and photon-based radiotherapy for rectal cancer.

RESULTS

Eight articles with a total of 127 patients met the inclusion criteria. There was significantly less irradiated small bowel with PBT compared to three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) (MD -17.01, CI [-24.06, -9.96], p < 0.00001 and MD -6.96, CI [-12.99, -0.94], p = 0.02, respectively). Similar dosimetric results were observed for bladder and pelvic bone marrow. Three studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43 %, 68 % and 77.2 %, and one study in primary rectal cancer with 100 % disease free survival.

CONCLUSION

PBT treatment plans revealed significantly less irradiation of OAR for rectal cancer compared to conventional photon-based radiotherapy. Trials for recurrent rectal cancer and PBT have shown promising results. There are currently no ongoing clinical trials for primary rectal cancer and PBT. More research is required to validate its potential role in dose escalation, higher complete response rate and organ preservation without increasing toxicity.

457 Survey of Perceived Barriers to Medical Students for Progression into Surgery

Introduction

Applications for surgical training have been decreasing despite higher numbers of medical school graduates. We sought to explore the perceived barriers to medical students for progression into surgery.

Method

An online anonymised SurveyMonkey® questionnaire aimed at medical students was disseminated in May 2020, with survey invitations advertised through social media.

Results

A total of 271 responses were obtained, with 95% of respondents being undergraduates and a 7:3 female to male ratio. Approximately one-fifth (19%) were considering pursuing a career in surgery. 82% of students had observed in an operating theatre. 54% of respondents agreed that their surgical rotation was a positive experience, 21% neutral, 8% negative.

Most frequent perceived barriers included lack of work-life balance (77%), surgical culture (67%), lengthy post-graduate training pathway (63%), and competitive entry of surgical specialties (63%). Others included a lack of understanding of surgical career pathways (52%), limited exposure to surgery (47%), and lack of interest (37%). Notably, gender bias was a barrier for many (35%). Most wanted more exposure to surgery through surgical skills teaching (85%), theatre experience (67%), surgical placements (59%) and didactic teaching (33%).

Conclusions

Modifiable barriers need to be addressed in undergraduate and postgraduate training to boost the number of applications into surgical training.

475 Acute Type A Aortic Dissection In-Hours Vs Out-Of-Hours: A Systematic Review and Meta-Analysis

Introduction

Acute type A aortic dissection (ATAAD) is a life-threatening medical emergency requiring immediate surgical intervention. We sought to compare clinical outcomes in patients with ATAAD that undergone surgical repair during in-hours (IH) versus out-of-hours (OOH).

Method

Electronic database search at PubMed, Ovid, Scopus, Cochrane and Embase was performed from inception till March 2020. Primary outcomes were 30-day mortality, stroke, and re-operation for bleeding; secondary outcomes were previous cardiac surgery and total arch replacement.

Results

Six articles with a total of 3,744 patients met the inclusion criteria. Re-operation for bleeding and stroke rate were similar, with 18% in IH vs 23% in OOH (RR 0.89, 95% CI [0.73, 1.08], p = 0.24), and 12% in IH vs 13% in OOH (RR 0.83, 95% CI [0.66, 1.03], p = 0.09) respectively. 30-day mortality was significantly lower in IH (26%) vs 24% in OOH (RR 0.81, 95% CI [0.72, 0.90], p = 0.0001). Previous cardiac surgery was higher in IH (5%) vs 4% in OOH patients (p = 0.005). Total arch replacement were similar in both cohorts, 29% in IH vs 32% in OOH (RR 0.96, 95% CI [0.89, 1.04], p = 0.37).

Conclusions

ATAAD operation during IH and OOH have comparable clinical outcomes. Therefore, operating on such cases should be decided on clinical priority without delay.

667 Virtual Learning During The COVID-19 Pandemic Amongst Medical Students in The United Kingdom

Introduction

Throughout the COVID-19 pandemic medical education has predominantly been delivered through virtual learning (VL). This survey was conducted to evaluate the effectiveness of VL amongst medical students in the UK.

Method

An online anonymised SurveyMonkey© survey was distributed through social media amongst UK medical students.

Results

There were 142 completed surveys, 96.5% of students engaged in some form of VL during the pandemic, compared to 57.8% prior to the pandemic. The most frequently used method to deliver teaching was interactive online lectures (74.7%). The students perceived small group online teaching sessions to be the most effective delivery method (weighted average 7.4/10) followed by interactive online lectures (7.4/10). The least effective teaching method was online lecture notes (5.3/10).

Accessibility to coursework (8.6/10) and enhanced flexibility (8.4/10) were considered to be the biggest advantages of VL. Overall, 44% of students felt VL had a negative impact on their learning, with 23% of students considered to have failed to meet the learning objectives set out in these sessions.

Conclusions

Beyond the COVID-19 pandemic VL will continue to play a role in medical education. However, there is room for improvement in both delivery and engagement to improve student experience and satisfaction.

455 Proton Beam Therapy in Rectal Cancer: A Systematic Review and Meta-Analysis

Introduction

Radiotherapy for locally advanced rectal cancer is conventionally performed using photon-based radiotherapy (PBR), carrying significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) potentially delivers equivalent dosimetric radiation to the targeted tissue with improved sparing of OAR. We aimed to compare dosimetric irradiation of OAR for PBT versus PBR in patients with rectal cancer and assess any oncological outcomes.

Method

An extensive electronic literature search was performed from inception till April 2020 and subsequent meta-analysis performed.

Results

Six articles met the inclusion criteria. Dosimetric data of irradiation delivered to OAR for PBT and PBR were calculated for the same patients. PBT had significantly less irradiated small bowel compared to 3DCRT and IMRT, (MD -16.95, 95% CI [-24.03, -9.88], p &lt; 0.00001) and (MD -6.96, 95% CI [-12.99, -0.94], p = 0.02) respectively. Similar results were observed for bladder and pelvic bone marrow. Two studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43% and 68%.

Conclusions

Dosimetric treatment plans have less irradiation of OAR for rectal cancer with PBT compared to PBR. There is a need for further research in PBT and rectal cancer, as promising results have been shown in recurrent rectal cancer.

The effect of GMFCS level, age, sex, and dystonia on multi-dimensional outcomes after selective dorsal rhizotomy: prospective observational study

PURPOSE

Investigate the effect of age category (1-9 years vs 10-18 years), sex, Gross Motor Function Classification System (GMFCS) level, and presence of dystonia on changes in eight function test parameters 24 months after selective dorsal rhizotomy (SDR).

METHODS

Prospective, single-center study of all children aged 3-18 years with bilateral cerebral palsy with spasticity who underwent SDR at a tertiary pediatric neurosurgery center between 2012 and 2019. A linear mixed effects model was used to assess longitudinal changes.

RESULTS

From 2012 to 2019, 42 children had follow-up available at 24 months. Mean GMFM-66 scores increased after SDR (mean difference 5.1 units: 95% CI 3.05-7.13, p < 0.001). Statistically significant improvements were observed in CPQoL, PEDI Self-care and Mobility, 6MWT, Gillette, and MAS scores. There was no significant difference in the improvements seen for age category, sex, GMFCS level, and presence of dystonia for most of the parameters tested (5/8, 6/8, 5/8, and 6/8 respectively).

CONCLUSION

SDR may improve gross and fine motor function, mobility and self-care, quality of life, and overall outcome based on extensive scoring parameter testing at 24 months. Atypical patient populations may benefit from SDR if appropriately selected. Multi-center, prospective registries investigating the effect of SDR are required.

Outcomes in techniques of valve sparing aortic root replacement: A systematic review and meta-analysis

OBJECTIVE

To compare clinical outcomes of reimplantation versus remodeling in patients undergoing valve-sparing aortic root replacement (VSRR) surgery.

METHOD

Electronic database search at PubMed, Scopus, Embase, Ovid, and Google scholar was performed from inception to January 2020. Primary outcomes were aortic valve (AV) reintervention and postoperative grade of aortic insufficiency (AI) while secondary outcomes were 30-day mortality, reoperation for bleeding, and operative times.

RESULTS

A total of 21 articles met the inclusion criteria. A total of 1283 patients had reimplantation while 1150 had remodeling. No difference in preoperative demographics was noted except reimplantation patients were younger (48 ± 16 vs. 56 ± 15 years; p < .00001). The cardiopulmonary bypass and aortic cross-clamp times were shorter in the remodeling cohort (168 ± 38 vs. 150 ± 37 min; p = .0001 and 133 ± 31 vs. 112 ± 30 min; p = .0002, respectively). No difference in concomitant total arch surgery (14% in reimplantation vs. 15% in remodeling; p = .53). Postoperatively, there were similar stroke rates (3% in both cohorts; p = .54), rates of reoperation for bleeding (9% in reimplantation vs. 12% in remodeling; p = .88), and 30-day mortality (3% in reimplantation vs. 4% in remodeling; p = .96). No difference in early AV reintervention (1% in reimplantation vs. 2% in remodeling; p = .07), and late AV reintervention (4% in reimplantation vs. 7% in remodeling; p = .07). The AI of +2 grade was significantly lower in the reimplantation cohort (5% vs. 8%; p = .01).

CONCLUSION

Our study shows comparable clinical outcomes between both techniques. The practice of each technique is largely center and surgeon dependent. Larger sample size cohorts with minimal confounding factors are required to confirm the above findings.

Acute type A aortic dissection in-hours versus out-of-hours: A systematic review and meta-analysis

OBJECTIVE

We sought to compare clinical outcomes in patients with acute type A aortic dissection that undergone surgical repair during in-hours (IH) versus out-of-hours (OOH).

METHODS

An electronic literature search was done till March 2020 to include studies with comparative cohorts of IH versus OOH. Primary outcomes were 30-day mortality, stroke, and reoperation for bleeding; secondary outcomes were acute kidney injury, total hospital stay, and intensive care unit stay.

RESULTS

Six articles with a total of 3744 patients met the inclusion criteria. Mean age was similar, 60 ± 12 versus 60 ± 13 in IH versus OOH (p = .25). Aortic root and total arch replacement were similar in both cohorts, 22% in IH versus 25% in OOH (risk ratio [RR], 1.10; 95% confidence interval [CI: 0.78, 1.55]; p = .58) and 29% in IH versus 32% in OOH (RR, 0.96; 95% CI [0.89, 1.04], p = .37) respectively. Reoperation for bleeding and stroke rate were similar, with 18% in IH versus 23% in OOH (RR, 0.89; 95% CI [0.73, 1.08]; p = .24), and 12% in IH versus 13% in OOH (RR, 0.83; 95% CI [0.66, 1.03]; p = .09) respectively. Thirty-day mortality was significantly lower in IH (RR, 0.81; 95% CI [0.72, 0.90]; p = .0001).

CONCLUSION

There was higher 30-day mortality rate during OOH surgery, yet this difference diminished following sensitivity analysis. There were no significant differences in major postoperative outcomes. Therefore, operating on such cases should be decided on clinical priority without delay.

Technique and outcome of day case laparoscopic hiatus hernia surgery for small and large hernias: a five-year retrospective review from a high-volume UK centre

INTRODUCTION

Laparoscopic anti-reflux surgery is the standard surgical treatment for gastro-oesophageal reflux disease in patients for who long-term pharmacotherapy is intolerable or ineffective. Advances in anaesthesia and minimally invasive surgery have led to day case treatment being adopted by some centres. The objective of this study is to describe our day case pathway and peri- and postoperative outcomes.

MATERIALS AND METHODS

This is a single centre, retrospective case series review of a prospectively collected database from October 2014 to August 2019 performed in a tertiary centre for upper gastrointestinal surgery. Data collected included demographics, comorbidities, indications, complications, length of stay and readmission.

RESULTS

A total of 362 patients underwent laparoscopic anti-reflux surgery with or without hiatus hernia repair of up to 10cm, with day case rates of 59%. Unplanned admission following day surgery was 5.1% (13/225) and 30-day readmission was 2.2% (8/362); 90.6% of patients remained in hospital for less than 24 hours. There was one intraoperative complication and one patient required revisional surgery within 30 days. The rate of all postoperative complications was 1.38% (5/362) with one postoperative mortality.

DISCUSSION

The inclusion of larger hernias is unusual, as most studies limit size to 5cm or less. Our results show the safety and feasibility of the procedure even when applied to hiatus hernias up to 10cm. Success was multifactorial and based on standardisation of procedures and support from dedicated specialist nursing staff.

CONCLUSION

Laparoscopic anti-reflux surgery can be performed safely as a day case procedure even in larger hiatus hernias, with a dedicated care pathway and specialist nurse practitioners to support it.

Ex vivo model for a new bilateral antimesenteric V-modified side-to-side isoperistaltic anastomosis to prevent recurrence in ileocolic Crohn's disease

INTRODUCTION

The high rate of recurrence following ileocaecal resection for Crohn's disease may lead to repeat surgery in 20-30% of patients at five years after surgery. Recurrence usually occurs at the anastomosis and the neoterminal ileum and the association of a strictureplasty to widen the bowel lumen in the regions immediately proximal ('anastomotic inlet') and distal ('anastomotic outlet') to the anastomosis may delay or reduce the risk of surgical recurrence.

MATERIALS AND METHODS

A side to side isoperistaltic anastomosis, with an associated V-modified strictureplasty on the anti-mesenteric border at the level of the anastomosis inlet and outlet has been designed. We produced a wet lab ex vivo model of the anastomosis and, to evaluate the different calibre of the anastomotic segments, we compared it with ex vivo models of three anastomotic configurations currently used in surgery for Crohn's disease: i) side to side isoperistaltic anastomosis; ii) modified side-to-side isoperistaltic anastomosis with double Heineke-Mikulicz procedure (Sasaki anastomosis); iii) anti-mesenteric functional end-to-end handsewn anastomosis (Kono-S anastomosis).

RESULTS

Differences were recorded at the level of the anastomosis inlet and outlet, with a larger volume estimated in the Sasaki anastomosis and in the V-modified anastomosis. The V-modified anastomosis had a larger volume compared with the Sasaki anastomosis for a longer segment of small bowel.

CONCLUSIONS

We have developed an experimental animal model for a new anastomotic technique which could be applied in surgery for Crohn's disease following small-bowel or ileocolic resection.

Cost-effectiveness of routine imaging of suspected appendicitis

Introduction The misdiagnosis of appendicitis and consequent removal of a normal appendix occurs in one in five patients in the UK. On the contrary, in healthcare systems with routine cross-sectional imaging of suspected appendicitis, the negative appendicectomy rate is around 5%. If we could reduce the rate in the UK to similar numbers, would this be cost effective? This study aimed to calculate the financial impact of negative appendicectomy at the Queen Alexandra Hospital and to explore whether a policy of routine imaging of such patients could reduce hospital costs. Materials and methods We performed a retrospective analysis of all appendicectomies over a 1-year period at our institution. Data were extracted on outcomes including appendix histology, operative time and length of stay to calculate the negative appendicectomy rate and to analyse costs. Results A total of 531 patients over 5 years of age had an appendicectomy. The negative appendicectomy rate was 22% (115/531). The additional financial costs of negative appendicectomy to the hospital during this period were £270,861. Universal imaging of all patients with right iliac fossa pain that could result in a 5% negative appendicectomy rate would cost between £67,200 and £165,600 per year but could save £33,896 (magnetic resonance imaging), £105,896 (computed tomography) or £132,296 (ultrasound) depending on imaging modality used. Conclusions Negative appendicectomy is still too frequent and results in additional financial burden to the health service. Routine imaging of patients with suspected appendicitis would not only reduce the negative appendicectomy rate but could lead to cost savings and a better service for our patients.

Successful Comparison of US Food and Drug Administration Sentinel Analysis Tools to Traditional Approaches in Quantifying a Known Drug-Adverse Event Association

The US Food and Drug Administration's Sentinel system has developed the capability to conduct active safety surveillance of marketed medical products in a large network of electronic healthcare databases. We assessed the extent to which the newly developed, semiautomated Sentinel Propensity Score Matching (PSM) tool could produce the same results as a customized protocol-driven assessment, which found an adjusted hazard ratio (HR) of 3.04 (95% confidence interval [CI], 2.81-3.27) comparing angioedema in patients initiating angiotensin-converting enzyme (ACE) inhibitors vs. beta-blockers. Using data from 13 Data Partners between 1 January 2008, and 30 September 2013, the PSM tool identified 2,211,215 eligible ACE inhibitor and 1,673,682 eligible beta-blocker initiators. The tool produced an HR of 3.14 (95% CI, 2.86-3.44). This comparison provides initial evidence that Sentinel analytic tools can produce findings similar to those produced by a highly customized protocol-driven assessment.

Rationale and design of a UK database for a rare cancer type: the GEM Registry for gastrointestinal stromal tumours

Background:

Despite advances in the management of and changes in clinical practice, little is known about the epidemiology, patterns of care and outcomes of gastrointestinal stromal tumour (GIST) patients in the UK. Patient registries are receiving increasing attention as they can provide important information on clinical practice and patient outcomes. The rationale and study design of the GIST Epidemiology and Management (GEM) Registry, which forms part of the routine clinical practice for GISTs in several UK centres, are described.

Methods:

The GEM Registry is a secure web-based registry system designed around a Microsoft Access core using SQL interface. Demographic, surgical, histopathological and clinical data will be captured including treatment outcomes and survival. The registry was piloted in six centres and following further fine tuning of the data sets, ethical committee submission and approval was completed.

Results:

The GEM National Registry is the first of its kind to be implemented in rare cancers in UK. The registry is being rolled out initially in selected centres with the aim to expand to other centres. The first publication reporting analyses of the central data set is anticipated for the summer of 2013.

Conclusion:

GEM Registry will enable us to obtain a clear picture of incidence/prevalence of GISTS in UK. Clinicians will be able to review the prognostic and predictive value of variables in a large prospective data set. The data can be used for planning the delivery and improving the quality of care. This information is likely to inform clinical practice and, in years to come, guide the development and implementation of clinical trials for novel tyrosine kinase inhibitors. The results will not only benefit the GIST community, but also serve as a basis for the study of other rare tumour types.

Time-dependent gene expression and immunohistochemical analysis of the injured anterior cruciate ligament

Objectives

This study aimed to investigate time-dependent gene expression of injured human anterior cruciate ligament (ACL), and to evaluate the histological changes of the ACL remnant in terms of cellular characterisation.

Methods

Injured human ACL tissues were harvested from 105 patients undergoing primary ACL reconstruction and divided into four phases based on the period from injury to surgery. Phase I was < three weeks, phase II was three to eight weeks, phase III was eight to 20 weeks, and phase IV was ≥ 21 weeks. Gene expressions of these tissues were analysed in each phase by quantitative real-time polymerase chain reaction using selected markers (collagen types 1 and 3, biglycan, decorin, α-smooth muscle actin, IL-6, TGF-β1, MMP-1, MMP-2 and TIMP-1). Immunohistochemical staining was also performed using primary antibodies against CD68, CD55, Stat3 and phosphorylated-Stat3 (P-Stat3).

Results

Expression of IL-6 was mainly seen in phases I, II and III, collagen type 1 in phase II, MMP-1, 2 in phase III, and decorin, TGF-β1 and α-smooth muscle actin in phase IV. Histologically, degradation and scar formation were seen in the ACL remnant after phase III. The numbers of CD55 and P-Stat3 positive cells were elevated from phase II to phase III.

Conclusions

Elevated cell numbers including P-Stat3 positive cells were not related to collagens but to MMPs’ expressions.

Arthroscopic partial limbectomy for labral injury of the hip: a case with a 16-year follow-up

Although good to excellent short-term results of arthroscopic partial limbectomy of the hip have been reported, there is little information on the long-term outcome of the procedure. We report a case with a 16-year follow-up. A 34-year old woman presented with a three-month history of severe pain and limitation of movement of the hip. Plain radiographs and arthrography showed no abnormality. MRI showed an effusion and a deformity of the anterosuperior part of the labrum. This was confirmed as an inverted labral tear that was debrided arthroscopically. At 16 years post-operatively, she remained symptom-free. Plain radiographs showed no abnormality and MRI suggested that the sealing effect of the scar tissue prevented articular damage and degeneration.

Comparative-effectiveness research in distributed health data networks

Comparative-effectiveness research (CER) can be conducted within a distributed health data network. Such networks allow secure access to separate data sets from different data partners and overcome many practical obstacles related to patient privacy, data security, and proprietary concerns. A scalable network architecture supports a wide range of CER activities and meets the data infrastructure needs envisioned by the Federal Coordinating Council for Comparative Effectiveness Research.

Knee osteoarthritis, knee joint pain and aging in relation to increasing serum hyaluronan level in the Japanese population

OBJECTIVE

To investigate relationship between serum hyaluronan (HA) level and the presence and severity of radiographic knee osteoarthritis (OA) as well as degree of knee pain in Japanese population.

DESIGN

A total of 616 volunteers participated in this study. Based on the Kellgren-Lawrence (K-L) grade, participants were radiographically classified into three groups: Normal (K-L grade 0 or 1), Moderate (grade 2) and Severe (grade 3 or 4). The degree of knee pain was quantified by visual analogue scale (VAS) and Knee injury and Osteoarthritis Outcome Score (KOOS) Pain. Serum HA levels were compared among the Normal, Moderate and Severe groups, and the relationship between serum HA level and the severity of knee OA was analyzed after age, sex and body mass index (BMI) were adjusted. In addition, the correlation between serum HA level and the degree of knee pain was analyzed in each group.

RESULTS

Regarding relationship between serum HA level and the severity of radiographic knee OA, serum HA levels of the Moderate and Severe groups were significantly higher than in the Normal group (P<0.001). Furthermore, serum HA level correlated with the severity of radiographic knee OA (r=0.289, P<0.001) after adjusting for age, sex and BMI. Serum HA level correlated with VAS of knee pain and/or KOOS Pain in the Normal and Moderate groups.

CONCLUSION

Serum HA level has the potential to be useful for the diagnosis of the presence and severity of knee OA.

Involvement of retinoic acid-inducible gene-I in inflammation of rheumatoid fibroblast-like synoviocytes

Interferon (IFN)-gamma is a major cytokine that regulates T helper 1-type immune reactions and serves as an important mediator in the pathogenesis of autoimmune diseases. Retinoic acid-inducible gene-I (RIG-I) is an IFN-gamma-inducible gene and known to be involved in the inflammatory and immune reactions. In the present study, we found high levels of RIG-I expression in synovial tissues of rheumatoid arthritis (RA), while the expression in osteoarthritis tissues was low. Treatment of cultured fibroblast-like synoviocytes with IFN-gamma markedly induced the expression of RIG-I. Knockdown of RIG-I in fibroblast-like synoviocytes, with specific siRNA, resulted in the inhibition of the IFN-gamma-induced expression of chemokine (C-X-C motif) ligand 10 (CXCL10)/IFN-gamma-inducible protein-10 (IP-10), a chemokine with chemotactic activity towards T cells. These findings suggest that RIG-I may play an important role in the pathogenesis of synovial inflammation in RA, at least in part, by regulating the IFN-gamma-induced expression of CXCL10/IP-10.

Evaluation of lengthened callus by callotasis with analysis of mathematical morphology

BACKGROUND

Callotasis has become an established option for reconstruction of congenital anomalies and after resection of bone tumors. However, fracture after removal of the lengthener remains one of the most serious complications. Mathematical morphology is an image processing technique that allows the skeletal patterns of trabecular bone to be selectively extracted as binary images from computed radiographic (CR) images. We evaluated the strength of the lengthened callus by analysis using mathematical morphology and examined the utility of this method in a biomechanical study.

METHODS

Three Japanese white rabbits per time point were euthanized at the 2-, 3-, 4-, 6-, and 8-week points after completion of the lengthening and were evaluated by CR images and analysis with mathematical morphology.

RESULTS

The changes of the number and continuity of trabecular bone were obtained visually and could be evaluated quantitatively. In some cases corticalization appeared to be complete in the CR images, but it was not complete on the morphological images. Such cases were found to be weaker than those in which corticalization appeared to be complete on both CR and morphological images.

CONCLUSION

Analysis with mathematical morphology is useful for evaluating the lengthened callus after callotasis.

Arthroscopic evaluation and treatment by tendon interpositional arthroplasty of first carpometacarpal joint arthritis

Basal joint arthritis of the thumb is usually seen in females beginning from the fourth and fifth decades. In the last two decades, arthroscopic techniques have brought new chances of diagnosis and treatment for this condition. In this paper, the authors describe the indications and their experience concerning arthroscopic hemitrapezectomy and tendon interposition using the palmaris longus tendon. A series of 16 patients with a maximum follow-up of 12 months is analysed. All of the 16 patients were followed and assessed with grasp strength, pinch strength, DASH and MAYO evaluation score both pre- and post-operatively at 12 months follow-up. According to the MAYO score, there were six excellent results, six good, three fair and one poor. No complications occurred. According to our preliminary results, this procedure with the proper indications gives a valid option for the treatment of thumb carpometacarpal joint arthritis in stages I and II according to Eaton's classification.

Locally administered low-dose alendronate increases bone mineral density during distraction osteogenesis in a rabbit model

We investigated the effect of locally administered bisphosphonate on distraction osteogenesis in a rabbit model and evaluated its systemic effect. An osteotomy on the right tibia followed by distraction for four weeks was performed on 47 immature rabbits. They were divided into seven equal groups, with each group receiving a different treatment regime. Saline and three types of dosage of alendronate (low, 0.75 μg/kg; mid, 7.5 μg/kg and high 75 μg/kg) were given by systemic injection in four groups, and saline and two dosages (low and mild) were delivered by local injection to the distraction gap in the remaining three groups. The injections were performed five times weekly during the period of distraction.

After nine weeks the animals were killed and image analysis and mechanical testing were performed on the distracted right tibiae and the left tibiae which served as a control group. The local low-dose alendronate group showed a mean increase in bone mineral density of 124.3 mg/cm3 over the local saline group (analysis of variance, p < 0.05) without any adverse effect on the left control tibiae.

The findings indicate that the administration of local low-dose alendronate could be an effective pharmacological means of improving bone formation in distraction osteogenesis.

Comparison of responsiveness of the Japanese Society for Surgery of the Hand version of the carpal tunnel syndrome instrument to surgical treatment with DASH, SF-36, and physical findings

BACKGROUND

The Japanese Society for Surgery of -the Hand version of the Carpal Tunnel Syndrome Instrument (CTSI-JSSH), which consists of two parts--one for symptom severity (CTSI-SS) and the other for functional status (CTSI-FS)--is a self-administered questionnaire specifically designed for carpal tunnel syndrome. The responsiveness of the CTSI-JSSH was compared with that of the JSSH version of the Disability of Arm, Shoulder, and Hand questionnaire (DASH), the official Japanese version of the 36-Item Short Form Health Survey (SF-36, version 1.2), and physical examinations to elucidate the role of the CTSI-JSSH for evaluating patients with carpal tunnel syndrome.

METHODS

Preoperatively, a series of 60 patients with carpal tunnel syndrome completed the CTSI-JSSH, DASH, and SF-36. Results of physical examinations, including grip strength, pulp pinch, and static two-point discrimination of the thumb, index, and long fingers, were recorded. Three months after carpal tunnel release surgery the patients were asked to fill out the same questionnaires, and the physical examinations were repeated. The responsiveness of all the instruments was examined by calculating the standardized response mean (SRM) and effect size (ES). Correlation coefficients were calculated between questionnaire change scores and patient satisfaction scores as well as between the CTSI change scores and those of the DASH and SF-36.

RESULTS

The largest responsiveness was observed in the CTSI-SS (SRM/ES: -1.00/-1.08) followed by the CTSI-FS (-0.76/-0.63), and bodily pain subscale of SF-36 (SF-36-BP, 0.45/0.55), and the DASH (-0.46/-0.47). Only the change scores of the CTSI-SS had significant correlation with patient satisfaction (r = 0.34, P < 0.01). An absolute value of Spearman's correlation coefficient of >0.5 was observed between the change scores of the CTSI-SS and the DASH, the CTSI-SS and the SF-36-BP, the CTSI-FS and the DASH, and the DASH and the SF-36-BP.

CONCLUSION

The CTSI-JSSH was proven to be more sensitive to clinical changes after carpal tunnel release than the other outcome measures and should be used to evaluate patients with carpal tunnel syndrome who speak Japanese as their native language.

Pathophysiological role of endothelin in ectopic ossification of human spinal ligaments induced by mechanical stress

Ossification of the posterior longitudinal ligament (OPLL) of the spine is characterized by progressive ectopic bone formation in the spinal ligament. To identify the genes related to ossification affected by mechanical stress during OPLL, analyses using cDNA microarray were carried out using cultured human spinal ligament cells that had been subjected to uniaxial cyclic stretching. Samples were obtained from a total of 14 patients: seven cervical or thoracic OPLL patients and seven control patients. Spinal ligament cells derived from tissues of OPLL (OPLL cells) and control (non-OPLL cells) patients were subjected to uniaxial sinusoidal cyclic stretching (0.5 Hz, 20% stretch) for various time periods (0-9 hours). cDNA microarrays revealed that ranges of distribution of both up- and downregulated genes evoked by cyclic stretching were significantly wider in OPLL cells than in non-OPLL cells. Increases in the mRNA expression of endothelin-1 (ET-1) as well as various marker genes related to ossification were also observed. mRNA expression of ET-1 and alkaline phosphatase was increased by mechanical stress in a time-dependent manner, while addition of ET-1 to static cultures of OPLL cells increased mRNA expression of alkaline phosphatase in a dose-dependent manner. During 9 hours of cyclic stretching, ET-1 release increased to about sixfold the amount observed in nonstretched cells. In non-OPLL cells, neither cyclic stretching nor ET-1 induced any increase in alkaline phosphatase expression. These results suggest that mechanical stress promotes the progression of ossification in OPLL cells through autocrine and/or paracrine mechanisms of ET-1.

Uni-axial cyclic stretch induces Cbfa1 expression in spinal ligament cells derived from patients with ossification of the posterior longitudinal ligament

Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic bone formation in the spinal ligaments. Mechanical stress, which acts on the posterior ligaments, is thought to be an important factor in the progression of OPLL. To clarify this mechanism, we investigated the effects of in vitro cyclic stretch (120% peak to peak, at 0.5 Hz) on cultured spinal ligament cells derived from OPLL (OPLL cells) and non-OPLL (non-OPLL cells) patients. The mRNA expressions of Cbfa1 (an osteoblast-specific transcription factor), type I collagen, alkaline phosphatase (ALP), osteocalcin and integrin beta1 (a mechanotransducer) were increased by cyclic stretch in OPLL cells, whereas no change was observed in non-OPLL cells. The effects of cyclic stretch on the spinal ligament tissues derived from OPLL and non-OPLL patients were also analyzed by immunohistochemistry using an antibody against Cbfa1. The expression of Cbfa1 was increased by cyclic stretch at the center of the spinal ligament tissues of OPLL patients, whereas no change was observed in the tissues of non-OPLL patients. Furthermore, U0126, a specific inhibitor of MAPK kinase (MEK), suppressed the stretch-induced mRNA expressions of Cbfa1, ALP and type I collagen in OPLL cells. These results suggest that in OPLL cells, mechanical stress is converted by integrin beta1 into intracellular signaling and that Cbfa1 is activated through the MAP kinase pathway. Therefore, we propose that mechanical stress plays a key role in the progression of OPLL through an increase in Cbfa1 expression.

Endoscopic treatment of delayed unions and nonunions with calcium phosphate paste

We describe a new therapeutic procedure using a bone filler in a calcium phosphate paste (bone paste) for endoscopic surgery for delayed unions and nonunions. Guided by radiography, the site of nonunion was confirmed. Two portals were created toward the nonunion site and, through each portal, the tissue around the nonunion site was released. While confirming the site of nonunion under endoscopy, scar tissue at the nonunion was excised to expose the bone. Next, the bone paste was injected into the space between bone fragments. This therapeutic modality is indicated most favorably in cases of open fractures, in cases after replantation in which soft tissue is severely damaged but one wants to preserve as much soft tissue as possible, and in cases of nonunion with satisfactory fixation but insufficient callus formation.

The Ishiguro extension block technique for the treatment of mallet finger fracture: indications and clinical results

The results of extension block Kirschner wire fixation for the treatment of mallet fractures of the distal phalanx were retrospectively assessed in 65 consecutive patients. The indications for this technique were the presence of a large bone fragment, and palmar subluxation or the loss of joint congruity of the distal interphalangeal joint. Using the Wehbé and Scheider classification there were 27 type IB, 19 type IIB, 17 type IA, and 2 type IIA fractures. According to the Crawford rating system there were 46% excellent, 32% good, 20% fair and 2% poor results. We believe that this technique, when properly applied, produces satisfactory results.

Laparoscopic surgery for large hiatus hernia

Background

The results of laparoscopic surgery for large symptomatic hiatus hernia were revieved prospectively.

Methods

This was a prospective review of large (greater than 10 cm) hiatus hernias treated by laparoscopic surgery at the Royal Adelaide Hospital from January 1994 to July 1997. Demographic data, preoperative investigations, operative findings, operating times, conversion rate, complications and follow-up were recorded prospectively.

Results

Some 48 patients with a large hiatus hernia were treated laparoscopically. All had repair of the hiatal pillars and 47 had a fundoplication. The median age was 58 (range 30–87) years and there were 25 women. There were 11 sliding, eight paraoesophageal and 29 mixed hiatus hernias, and 20 completely intrathoracic stomachs. Median operating time was 75 (range 48–195) min and there were 12 conversions to an open operation; four because of difficulty reducing the hernia, three for obesity, two for bleeding, two because it was not possible to define the anatomy and one for gastric perforation. The majority of conversions occurred earlier in this experience and a change in technique to dissecting the sac out of the thoracic cavity reduced the conversion rate (38 to 15 per cent; P = 0·03, Fisher's exact test). Complications occurred in eight patients and resulted in early reoperation in two (one open and one laparoscopic). There was no death. The median stay was 3 (range 2–10) days. At a median follow-up of 19 (range 3–46) months, eight patients had minor dysphagia and two patients had an incisional hernia (both converted to open operation). One patient had a recurrent paraoesphageal hernia at 6 months and required further surgery. Median satisfaction scores were 10 (range 7–10) of 10 and all patients said they would have the operation again.

Conclusion

Large hiatus hernias can be effectively treated laparoscopically. The initial high rate of conversion to open operation was reduced by a change in operative technique.

Anatomical study of the carpal attachment of the triangular fibrocartilage complex

There have been few descriptions of the site of attachment onto the triquetrum, the so-called meniscal homologue, of the triangular fibrocartilage complex (TFCC). We have investigated the sites of attachment onto the triquetrum of 87 TFCCs collected from embalmed cadavers.

All TFCCs were smoothly attached to the triquetrum. In 79 (46 cases, 90%) they were attached to the triquetrum and fifth metacarpal bone, and in eight (5 cases, 10%) they were attached widely on the articular surface of the triquetrum.

It is necessary to have accurate positional information about the normal triquetrum and TFCC in order to perform arthroscopy. The meniscal homologue attached to the triquetrum is smooth in almost all cases. In about 10% of joints the TFCC is attached to the lunotriquetral ligament, either partly or completely obscuring the articular surface of the triquetrum.

Distraction lengthening by callotasis in the hand

The clinical results of 26 digits (18 patients) lengthened by distraction callotasis were evaluated and the factors which influenced healing were analysed. There were 14 men and four women, with a mean age of 39 years. All digits had suffered traumatic amputation. There were eight thumbs and 18 fingers. The level of the site of the osteotomy was at the proximal metaphysis in ten, the middle diaphysis in 13 and the distal metaphysis in three.

Although the proposed length was achieved in 23 of the 26 digits, five required additional bone grafts. The rate of healing was 96 days/cm in the digits without complications such as callus fracture or poor callus formation, and 158 days/cm in those with complications. Lengthening at the proximal metaphysis gave a better result than at the diaphysis or distal metaphysis.

Distraction lengthening by callotasis in the hand

The clinical results of 26 digits (18 patients) lengthened by distraction callotasis were evaluated and the factors which influenced healing were analysed. There were 14 men and four women, with a mean age of 39 years. All digits had suffered traumatic amputation. There were eight thumbs and 18 fingers. The level of the site of the osteotomy was at the proximal metaphysis in ten, the middle diaphysis in 13 and the distal metaphysis in three. Although the proposed length was achieved in 23 of the 26 digits, five required additional bone grafts. The rate of healing was 96 days/cm in the digits without complications such as callus fracture or poor callus formation, and 158 days/cm in those with complications. Lengthening at the proximal metaphysis gave a better result than at the diaphysis or distal metaphysis.

The carpal detachment injury of the triangular fibrocartilage complex

Triangular fibrocartilage complex (TFCC) injuries were suspected clinically in 22 wrists of 21 patients, but arthrography and MRI assessments of this structure were normal. As conservative therapy for 2 months did not improve their symptoms, wrist arthroscopy was then performed. Although no abnormalities of the TFCC and ligaments were observed, meniscus homologue-like tissue which arose from TFCC was riding on the articular surface of the triquetrum. After resection of this soft tissue with a shaver and a punch, the symptoms disappeared in all cases. The arthroscopic findings suggested that a portion of TFCC that was originally attached to the ulnar side of the triquetrum had become detached.

Treatment of soft tissue injuries to the dorsum of the metacarpophalangeal joint (Boxer's knuckle)

We retrospectively reviewed the surgical treatment for 16 cases of traumatic soft tissue injury to the metacarpophalangeal joint (Boxer's knuckle). A history of trauma was present in all cases and there was an associated extensor tendon dislocation in seven cases. Eight cases were initially treated conservatively, but their symptoms persisted. Intraoperative findings included rupture of the extensor hood or joint capsule in all cases. Surgical closure of the rupture of the joint capsule resulted in a successful outcome in all cases. We consider that conservative treatment of this injury may not be effective when the joint capsule of the metacarpophalangeal joint is ruptured. We recommend arthrography of the metacarpophalangeal joint to assist in the decision as to whether to proceed with surgical or conservative treatment.

Arthroscopic diagnosis and treatment of dorsal wrist ganglion

Thirty-seven patients with dorsal wrist ganglia underwent arthroscopic resection. The mean follow-up was 20 months, and no complications were encountered. The ganglia were classified into three types according to their arthroscopic appearance. This classification helps to determine the amount of dorsal capsular resection required.

Surgical approach to the spinal accessory nerve for brachial plexus reconstruction

An easy, safe, and less invasive surgical approach to the spinal accessory nerve for brachial plexus reconstruction is described. The technique avoids a longitudinal unsightly scar over the neck and preserves the branches innervating the upper part of the trapezius.

Ipsilateral pedicle vascularized fibula grafts for reconstruction of tibial defects and non-unions

Between October 1983 and August 1998, 31 patients with non-union or bone defect of the tibia have undergone 32 vascularized fibula transfers to reconstruct lower legs. Of these 32 vascularized fibula transfers, there were 19 pedicle transfers from the ipsilateral leg. There were 17 males and two females. The average patient age was 53 (21 to 84) years old. All patients achieved good bone reconstruction. All patients are currently able to walk without a brace, except for one. As to major complications, three of these 19 had delayed union, with only one postoperative fracture. In the cases with delayed union or fractured grafted fibulas, the periods to walking without a brace were longer than in the cases without such major complications. From the results, the ipsilateral pedicle vascularized fibula graft appears to be a useful option for reconstruction of tibial defects.

Combining free vascularized fibula graft and the Ilizarov external fixator: recent approaches to congenital pseudarthrosis of the tibia

The present study compares a recent approach for congenital pseudarthrosis of the tibia, combining a free vascularized fibula graft and an Ilizarov external fixator. Between 1984 and 1993, seven vascularized fibula grafts were performed. In the first six cases, casts or unilateral external fixators were applied, and five of these cases were complicated by fractures of the graft, necessitating secondary procedures or long-term immobilization. The mean follow-up was 12.1 years. Five patients can now walk unassisted, and one uses a brace only outdoors. On average, a brace was required for 18 months. In the recent Ilizarov external fixator case, the fixator was removed after 4 months and a brace was unnecessary at 10 months. There was no leg-length discrepancy, severe ankle deformity, or fracture of the grafted fibula 7 years postoperatively. Combining a free vascularized fibula graft with an Ilizarov external fixator is recommended for this condition.