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Lewis TL, Robinson PW, Ray R, Dearden PMC, Goff TAJ, Watt C, Lam P. Five-Year Follow-up of Third-Generation Percutaneous Chevron and Akin Osteotomies (PECA) for Hallux Valgus. Foot Ankle Int 2023; 44:104-117. [PMID: 36692121 DOI: 10.1177/10711007221146195] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Recent large studies of third-generation minimally invasive hallux valgus surgery (MIS) have demonstrated significant improvement in clinical and radiologic outcomes. It remains unknown whether these clinical and radiologic outcomes are maintained in the medium to long term. The aim of this study was to investigate the minimum 5-year clinical and radiologic outcomes following third-generation MIS hallux valgus surgery in the hands of a high-volume MIS surgeon. METHODS A retrospective observational single highly experienced MIS surgeon case series of consecutive patients undergoing primary isolated third-generation percutaneous chevron and Akin osteotomies (PECA) for hallux valgus with a minimum 60-month clinical and radiographic follow-up. Primary outcome was radiographic assessment of the hallux valgus angle (HVA) and intermetatarsal angle (IMA) preoperatively, 6 months, and ≥60 months following PECA. Secondary outcomes included the Manchester-Oxford Foot Questionnaire, patient satisfaction, EuroQol-5D visual analog scale and the visual analog scale for pain. RESULTS Between 2012 and 2014, 126 consecutive feet underwent isolated third-generation PECA, with complete data available for 78 (61.9%) feet. The median follow-up was 65.0 (IQR 64-69; range 60-88) months. There was a significant improvement in radiographic deformity correction; the median IMA improved from 12.0 degrees (interquartile range [IQR]: 10.8-14.2) to 6.0 degrees (IQR: 4.2-7.3) (P < .001), and the median HVA improved from 27.2 degrees (IQR: 20.6-34.4) to 7.2 degrees (IQR: 3.4-11.6). Median MOXFQ Index score at ≥60-month follow-up was 2.3 (IQR: 0.0-7.8). The radiographic recurrence rate (defined as HVA >15 degrees) was 7.7% at final follow-up. The complication rate was 4.8%. CONCLUSION Radiologic deformity correction for the 78 feet we were able to follow that had third-generation PECA performed by a single highly experienced MIS surgeon was found to be maintained at a mean follow-up of average 66.8 months, with a radiographic recurrence rate of 7.7%. Clinical PROMs and patient satisfaction levels were high and comparable to other third-generation studies with shorter duration of follow-up. LEVEL OF EVIDENCE Level IV, retrospective cohort study.
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Affiliation(s)
- Thomas L Lewis
- King's Foot and Ankle Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Peter W Robinson
- Avon Orthopaedic Centre, Southmead Hospital, Bristol, United Kingdom
| | - Robbie Ray
- King's Foot and Ankle Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | | | - Thomas A J Goff
- Mid Yorkshire Hospitals NHS Trust, Wakefield, United Kingdom
| | - Clare Watt
- Orthopaedic and Arthritis Specialist Centre, Chatswood, Sydney, Australia
| | - Peter Lam
- Orthopaedic and Arthritis Specialist Centre, Chatswood, Sydney, Australia
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Lewis TL, Robinson PW, Ray R, Goff TAJ, Dearden PMC, Whitehouse MR, Lam P, Dracopoulos G. The Learning Curve of Third-Generation Percutaneous Chevron and Akin Osteotomy (PECA) for Hallux Valgus. J Foot Ankle Surg 2022; 62:162-167. [PMID: 35868982 DOI: 10.1053/j.jfas.2022.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 06/10/2022] [Accepted: 06/11/2022] [Indexed: 02/03/2023]
Abstract
The learning curve to reach technical proficiency for third-generation percutaneous or minimally invasive chevron and Akin osteotomies (PECA/MICA) is recognized to be steep however it is poorly defined in the literature. This study is a retrospective review of the first 58 consecutive PECA cases of a single surgeon. The primary outcome was the number of cases required to reach technical proficiency as defined by the operation time. Secondary outcomes included radiation exposure, radiographic deformity correction, and complication rates. Between November 2017 and March 2019, 61 consecutive PECA cases were performed with outcome data available for 58 of these (95%). Technical proficiency was reached after 38 cases. Operation time and radiation exposure significantly decreased after this transition point (p < .05). There was no difference in complication rate or radiographic deformity correction regardless of position along the learning curve (p > .05). In conclusion, the mean number of cases required to reach technical proficiency in third-generation PECA is 38 cases. The complication rate does not correlate to the number of cases performed, therefore surgeons interested in learning minimally invasive surgery can be reassured that there is unlikely to be an additional risk of harm to a patient during the learning curve.
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Affiliation(s)
- T L Lewis
- King's Foot and Ankle Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - P W Robinson
- Avon Orthopaedic Centre, Southmead Hospital, Bristol, United Kingdom.
| | - R Ray
- King's Foot and Ankle Unit, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - T A J Goff
- Mid Yorkshire Hospitals NHS Trust, Wakefield, United Kingdom
| | | | - M R Whitehouse
- Musculoskeletal Research Unit, Bristol Medical School, Southmead Hospital, University of Bristol, Bristol, United Kingdom; National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, England
| | - P Lam
- Orthopaedic and Arthritis Specialist Centre, Chatswood, Sydney, Australia
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Lewis TL, Goff TAJ, Ray R, Varrall CR, Robinson PW, Fogarty K, Chang A, Dhaliwal J, Dearden PMC, Wines A. Randomized Controlled Trial of Topical Skin Adhesive vs Nylon Sutures for Incision Closure in Forefoot Surgery. Foot Ankle Int 2021; 42:1106-1114. [PMID: 33870760 DOI: 10.1177/10711007211002501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND There are many options for incision closure in forefoot surgery. The aim of this study was to compare topical skin adhesive (2-octyl-cyanoacrylate) to simple interrupted nylon sutures. METHODS A prospective randomized controlled trial comparing topical skin adhesive (TSA) and nylon sutures (NSs) for elective open forefoot surgery. Primary outcome was Hollander Wound Evaluation Scale (HWES) assessed 2 weeks following surgery. Secondary objectives included time taken for wound closure, wound assessment, patient satisfaction with wound cosmesis, incision pain, and infection rate. RESULTS Between January and December 2018, 84 feet (70 patients) underwent hallux valgus scarf/Akin osteotomy or first metatarsophalangeal arthrodesis and were randomized to receive either intervention (topical skin adhesive) or control (3/0 nylon sutures). We found worse HWES scores when using TSA compared to NSs (1.07 vs 0.60). Incision closure time was slower for TSA (mean, 272 vs 229 seconds). At 2 weeks postoperatively, wound care was faster for TSA (mean 71 secs) vs NSs (mean 120), and patient-reported pain was less with TSA (visual analog scale: TSA 1.2 vs NSs 2.1). A high degree of overall patient satisfaction was reported in both groups, without significant difference. CONCLUSION Closure of elective forefoot surgery incisions with topical skin adhesive or interrupted nylon sutures offers high satisfaction rates, low pain scores, and low complications. However, topical skin adhesive was associated with more inflammation and areas of wound separation compared to nylon sutures. We recommend the use of sutures for wound closure in forefoot surgery. LEVEL OF EVIDENCE Level I, randomized controlled trial.
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Affiliation(s)
- Thomas L Lewis
- King's Foot and Ankle Unit, King's College NHS Foundation Trust, Orpington, UK
| | | | - Robbie Ray
- King's Foot and Ankle Unit, King's College NHS Foundation Trust, Orpington, UK
| | | | | | - Karen Fogarty
- North Sydney Orthopaedic and Sports Medicine Centre, Wollstonecraft, Australia
| | - Alice Chang
- Bankstown-Lidcombe Hospital, Bankstown, Australia
| | | | | | - Andrew Wines
- North Sydney Orthopaedic and Sports Medicine Centre, Wollstonecraft, Australia
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Robinson PW, Ray R, Goff TA, Dearden PM, Watt C, Smith M, Lam P. Percutaneous Chevron Akin (Peca) Osteotomy for Treatment of Hallux Valgus Deformity: The Long- Term Results. Foot & Ankle Orthopaedics 2020. [PMCID: PMC8705421 DOI: 10.1177/2473011420s00074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Category: Bunion Introduction/Purpose: Little is known about the long-term results of percutaneous hallux valgus correction, particularly the recurrence rate and factors leading to recurrence. Methods: We retrospectively reviewed a single surgeon consecutive series of percutaneous chevron and akin osteotomies (PECA) performed between 2012-14 on 127 feet in 86 patients. Mean age was 52+-13 years at surgery and mean follow up (FU) was 69+-7 months. Patient reported outcome measures (PROMs) were completed by 65 patients (MOXFQ, VAS pain (0-100)) and Likert satisfaction scale by 86 patients. Pre-operative, 6 month and final follow up weight bearing radiographs were available for 68 feet. Radiological parameters measured were the hallux valgus angle (HVA) and 1-2 intermetatarsal angle (IMA). The data was normally distributed and presented as mean+-SD. Paired t-test was used to compare pre- and post-operative angles. Ordinal logistic regression was used to test for significant dependent variables on PROMs. Results: Mean MOXFQ was 10+-16 and mean VAS pain was 6+-13 out of 100 at a mean FU of 69+-7 months. 99% (85/86) patients were highly satisfied or satisfied. Mean HVA improved from 28.3+-8.1º to 8.4+-5.6º at final FU (p<0.001). No clinically relevant difference in HVA was seen between 6 months and final FU. Mean IMA improved from 12.7+-2.9º to 6.2+-2.7º at final FU (p<0.001). 2.9% (2/68) had an HVA >20º at final FU, these both started with a pre-operative HVA >40°. Pre-operative HVA >40º was significantly more likely to have an HVA >20º at final FU than those with pre-operative HVA <40º (22% vs 0%, p<0.001). There were 5 re-operations for removal of screws. 1 foot had hallux varus, but was still satisfied. Conclusion: The 5 year results for PECA hallux valgus correction show high levels of patient satisfaction, function and pain relief, with low complication and re-operation rates. Radiological correction is maintained at long term FU.
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Scott LJ, Jones T, Whitehouse MR, Robinson PW, Hollingworth W. Exploring trends in admissions and treatment for ankle fractures: a longitudinal cohort study of routinely collected hospital data in England. BMC Health Serv Res 2020; 20:811. [PMID: 32867779 PMCID: PMC7457765 DOI: 10.1186/s12913-020-05682-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 08/23/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Evidence on the most effective and cost-effective management of ankle fractures is sparse but evolving. A recent large RCT in older patients with unstable fractures found that management with close-contact-casting was functionally equivalent and more cost-effective than internal fixation. We describe temporal and geographic variation in ankle fracture management and estimate the potential savings if close-contact-casting was used more often in older patients. METHODS Patients admitted to hospital in England between 2007/08 and 2016/17 with an ankle fracture were identified using routine hospital episode statistics. We tested whether the use of internal fixation, and the proportion of internal fixations using intramedullary implants, changed over time. We estimated the potential annual cost savings if patients aged 60+ years were treated with close-contact-casting rather than internal fixation, in line with emerging evidence. RESULTS Over the 10-year period, there were 223,465 hospital admissions with a primary ankle fracture diagnosis. The incidence (per 100,000) of internal fixation was fairly consistent over time in younger (33.2 in 2007/08, 30.9 in 2016/17) and older (36.5 in 2007/08, 37.4 in 2016/17) patients. The proportion of internal fixations which used intramedullary implants increased in both age groups (17.0-19.5% < 60 years; 15.2-17.4% 60+ years). In 2016/17, the cost of inpatient hospital care for ankle fractures in England was over £63.1million. If 50% of older patients who had an internal fixation instead had close-contact-casting, we estimate that approximately £1.56million could have been saved. CONCLUSIONS Despite emerging evidence that non-surgical and surgical management achieve equivalent functional outcomes in older patients, the rate of surgical fixation has remained relatively stable over the decade. The health service could achieve substantial savings if a higher proportion of older patients were treated with close-contact-casting, in line with recent evidence.
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Affiliation(s)
- Lauren J Scott
- NIHR ARC West, University Hospitals Bristol and Weston NHS Foundation Trust, 9th Floor Whitefriars, Lewins Mead, Bristol, BS1 2NT, UK.
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS8 2PS, UK.
| | - Tim Jones
- NIHR ARC West, University Hospitals Bristol and Weston NHS Foundation Trust, 9th Floor Whitefriars, Lewins Mead, Bristol, BS1 2NT, UK
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS8 2PS, UK
| | - Michael R Whitehouse
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical School, 1st Floor Learning & Research Building, Southmead Hospital, Bristol, BS10 5NB, UK
- National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, UK
- Avon Orthopaedic Centre, Southmead Hospital, North Bristol NHS Trust, Westbury-on-Trym, Bristol, BS10 5NB, UK
| | - Peter W Robinson
- Avon Orthopaedic Centre, Southmead Hospital, North Bristol NHS Trust, Westbury-on-Trym, Bristol, BS10 5NB, UK
| | - William Hollingworth
- NIHR ARC West, University Hospitals Bristol and Weston NHS Foundation Trust, 9th Floor Whitefriars, Lewins Mead, Bristol, BS1 2NT, UK
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS8 2PS, UK
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Dearden PMC, Ray RI, Robinson PW, Varrall CR, Goff TJ, Fogarty KA, Wines AP. Clinical and Radiological Outcomes of Forefoot Offloading Versus Rigid Flat Shoes in Patients Undergoing Surgery of the First Ray. Foot Ankle Int 2019; 40:1189-1194. [PMID: 31303022 DOI: 10.1177/1071100719858621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND It is common clinical practice to use either flat or reverse camber shoes to protect the foot for up to 6 weeks after surgery for hallux valgus or hallux rigidus. To date there is a paucity of evidence as to whether there is any difference between these 2 postoperative shoes, in either patient satisfaction or clinical outcomes. METHODS One hundred consecutive patients undergoing scarf/Akin osteotomies or first metatarsophalangeal joint (MTPJ) arthrodesis were recruited. Patients were randomized 50:50 to either flat or reverse camber postoperative shoes. Patients undergoing ancillary lesser toe procedures were not excluded. Patient satisfaction was assessed by visual analog scale (VAS) pain score and Likert satisfaction survey. Radiographic outcomes were reviewed at 1 year observing differences in fusion rates or deformity recurrence. There were 47 patients in the reverse cam and 43 in the flat shoe group. No difference in primary forefoot operation, additional operation, age at surgery, or preop VAS pain score was seen. RESULTS At 6 weeks, there was no significant difference in postop VAS pain score. The flat shoe group was significantly more likely to be satisfied with their general mobility (86.0% vs 61.7%; P = .01) and with their stability in the shoe (90.7% vs 69.6%; P = .03). No significant difference was seen between groups for nonunion or hallux valgus recurrence rates. CONCLUSION Both forms of postoperative footwear were effective in enabling patients to mobilize and in preventing adverse outcomes. Patients were more likely to be satisfied with a flat postoperative shoe due to improved stability and ease of mobilizing. The results of this study aid surgeon decision making for postoperative footwear in forefoot surgery. LEVEL OF EVIDENCE Level II, prospective randomized controlled trial.
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Affiliation(s)
- Paul M C Dearden
- Department of Trauma and Orthopaedics, Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Leeds, UK
| | - Robbie I Ray
- Sydney Orthopaedic Foot and Ankle Research Institute, Wollstonecraft, NSW, Australia
| | - Peter W Robinson
- Sydney Orthopaedic Foot and Ankle Research Institute, Wollstonecraft, NSW, Australia
| | - Caroline R Varrall
- Sydney Orthopaedic Foot and Ankle Research Institute, Wollstonecraft, NSW, Australia
| | - Thomas J Goff
- Sydney Orthopaedic Foot and Ankle Research Institute, Wollstonecraft, NSW, Australia
| | - Karren A Fogarty
- Sydney Orthopaedic Foot and Ankle Research Institute, Wollstonecraft, NSW, Australia
| | - Andrew P Wines
- Sydney Orthopaedic Foot and Ankle Research Institute, Wollstonecraft, NSW, Australia
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Uppal HS, Robinson PW, Packham I, Crowther M. The management of bilateral posterior fracture dislocations of the shoulder: a case series illustrating management options. Shoulder Elbow 2016; 8:111-7. [PMID: 27583008 PMCID: PMC4950465 DOI: 10.1177/1758573215626105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/14/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although dislocation of the shoulder is a relatively common event, the overwhelming majority of injuries are anterior. Posterior shoulder dislocation is more uncommon, comprising between 3% and 5% of all shoulder dislocations. One percent of shoulder dislocations involve a fracture, whereas only 0.9% of the 1500 cases reported by Neer (J Bone Joint Surg Am 1970; 52:1077-89; J Bone Joint Surg Am 1970; 52:1090-103) concerned posterior fracture dislocations. Bilateral posterior fracture dislocation is an even rarer event, comprising just 5% of all posterior fracture dislocations. Given the rarity and relative poor outcome often observed after these severe injuries, it is important that upper limb function is optimized. METHODS Bilateral posterior fracture dislocations of the shoulder pose a difficult clinical challenge that requires careful management planning. To date, there have been three isolated case reports of using contralateral osteochondral humeral autograft and hemiarthroplasty. We report our experiences and clinical outcomes in managing four such cases using a variety and combination of treatments, including the first reported use of reverse shoulder arthroplasty with contralateral osteochondral humeral autografting. RESULTS Shoulders reconstructed with humeral autograft demonstrated superior Oxford Shoulder Scores and an improved range of motion, as measured by a markerless machine vision system, compared to hemiarthroplasty. CONCLUSIONS Our results support the use of a contralateral humeral autograft in bilateral posterior shoulder fracture dislocation.
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Affiliation(s)
- Harpal S Uppal
- Harpal S Uppal, Shoulder Unit, North Bristol NHS Trust, Southmead Hospital, Bristol BS10 5NB, UK. Tel: +44 (0)1179505050.
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Sullivan NPT, Robinson PW, Ansari A, Hassaballa M, Robinson JR, Porteous AJ, Eldridge JD, Murray JRD. Bristol index of patellar width to thickness (BIPWiT): a reproducible measure of patellar thickness from adult MRI. Knee 2014; 21:1058-62. [PMID: 25108841 DOI: 10.1016/j.knee.2014.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 06/29/2014] [Accepted: 07/09/2014] [Indexed: 02/02/2023]
Abstract
BACKGROUND The restoration of an adequate patellar thickness is a key to the successful outcome of knee arthroplasty. This study investigated the relationship between the thickness of the native patellar and medial-lateral patellar width using magnetic resonance imaging (MRI). METHODS 75 MRI scans of young adults, with an average age of 27 (range 16-40) were studied. Exclusion criteria included a diagnosis of degenerative joint disease, patello-femoral pathology or age under 16/over 40 (170 patients). The bony thickness of the patellar, the chondral thickness and patellar width were measured, as was the location of maximal patellar thickness. Inter/intraobserver variability was calculated and correlation analysis was performed. RESULTS We found a strong correlation between patellar width and thickness (bone plus cartilage) (Pearson 0.75, P<0.001). The mean width to thickness ratio was 1.8:1 (standard deviation 0.1, 95% confidence interval 1.78-1.83). Without cartilage the ratio was 2.16:1 (SD 0.15, 95% CI 2.11-2.21), correlation was moderate (Pearson 0.59, P<0.001). The average maximal patellar cartilage thickness was 4.1mm (SD 1.3). CONCLUSION The strong correlation and narrow confidence intervals for the ratio of patellar width to thickness, suggest that patellar width might be used as a guide for accurate restoration of patellar thickness during total knee or patello-femoral replacement. After removing osteophytes we would recommend a ratio of 1.8:1. Further work is required to establish whether there is a relationship between anterior knee pain post total knee arthroplasty and an abnormal patellar width:thickness ratio. LEVEL OF EVIDENCE Level III.
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Affiliation(s)
- N P T Sullivan
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK.
| | - P W Robinson
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
| | - A Ansari
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
| | - M Hassaballa
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
| | - J R Robinson
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
| | - A J Porteous
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
| | - J D Eldridge
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
| | - J R D Murray
- Avon Orthopaedic Centre, North Bristol NHS Trust, Bristol, UK; Bristol Knee Group, Avon Orthopaedic Centre, North Bristol Trust, UK
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Affiliation(s)
- P W Robinson
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA.
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Abstract
The effectiveness of trial-and-error, graded-choice, and verbal-instruction procedures on the acquisition and maintenance of a two-choice simultaneous color discrimination in an intradimensional double-reversal learning situation was studied using 18 first-grade children. After acquiring a red-green discrimination during one 70-trial session, the discriminative roles of the stimuli were reversed for 30 trials, followed by a second reversal for 30 trials. Children in the graded-choice and verbal-instruction groups acquired and maintained the discriminations with fewer errors than children who learned by trial and error. The importance of the results in terms of two-stage discrimination learning theories is pointed out and similarities between errorless learning and overtraining are discussed.
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Abstract
The study investigated the effect of total darkness on the key pecking of pigeons under fixed-ratio, variable-ratio, fixed-interval, and variable-interval schedules of food reinforcement. Eight pigeons were divided into groups of two, with each group conditioned to peck under one of the four schedules of reinforcement. Under an ABAB procedure, all pigeons experienced alternating light and dark conditions. The house- and keylights were (a) maintained at full intensity for the first 30 one-hour sessions, (b) faded out and disconnected over Sessions 31 through 50, (c) totally illuminated for Sessions 51 to 60, and (d) disconnected again for the final 10 sessions. Responding under the ratio schedules increased from 20% to 108% in the dark and responding under the interval schedules in the dark decreased by 37% to 93%.
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Abstract
A simultaneous, two-choice color discrimination was carried out with three groups of four- to seven-year-old children. For Groups I and II, the opportunity to respond to the incorrect stimulus was controlled (graded) over three different conditions. First, only a red light (S+) and its retractable bar were presented (16 trials for Group I and 316 trials for Group II). Second, a green light (S-) was added with its correlated bar retracted for 14 trials. Third, 40 trials were given with both stimuli on and their correlated retractable bars extended. The opportunity to respond to S- was not graded for Group III children. They experienced only the third condition applied to Groups I and II. Responses to S+ were reinforced for all three groups, while responses to S- were not. Children in the first two groups made from zero to three responses to S-, while the control children emitted 11 to 46 errors. The results demonstrate that fading in S- or presenting S- early in the training procedure are sufficient, but not necessary conditions for errorless learning.
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Hassrick JL, Crocker DE, Teutschel NM, McDonald BI, Robinson PW, Simmons SE, Costa DP. Condition and mass impact oxygen stores and dive duration in adult female northern elephant seals. ACTA ACUST UNITED AC 2010; 213:585-92. [PMID: 20118309 DOI: 10.1242/jeb.037168] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The range of foraging behaviors available to deep-diving, air-breathing marine vertebrates is constrained by their physiological capacity to breath-hold dive. We measured body oxygen stores (blood volume and muscle myoglobin) and diving behavior in adult female northern elephant seals, Mirounga angustirostris, to investigate age-related effects on diving performance. Blood volume averaged 74.4+/-17.0 liters in female elephant seals or 20.2+/-2.0% of body mass. Plasma volume averaged 32.2+/-7.8 liters or 8.7+/-0.7% of body mass. Absolute plasma volume and blood volume increased independently with mass and age. Hematocrit decreased weakly with mass but did not vary with age. Muscle myoglobin concentration, while higher than previously reported (7.4+/-0.7 g%), did not vary with mass or age. Pregnancy status did not influence blood volume. Mean dive duration, a proxy for physiological demand, increased as a function of how long seals had been at sea, followed by mass and hematocrit. Strong effects of female body mass (range, 218-600 kg) on dive duration, which were independent of oxygen stores, suggest that larger females had lower diving metabolic rates. A tendency for dives to exceed calculated aerobic limits occurred more frequently later in the at-sea migration. Our data suggest that individual physiological state variables and condition interact to determine breath-hold ability and that both should be considered in life-history studies of foraging behavior.
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Affiliation(s)
- J L Hassrick
- Institute of Marine Sciences, University of California at Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA.
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Simmons SE, Crocker DE, Hassrick JL, Kuhn CE, Robinson PW, Tremblay Y, Costa DP. Climate-scale hydrographic features related to foraging success in a capital breeder, the northern elephant seal Mirounga angustirostris. ENDANGER SPECIES RES 2010. [DOI: 10.3354/esr00254] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Robinson PW, Scott RR. The toxicity of cyromazine toChironomus zealandicus(chironomidae) andDeleatidiumsp. (leptophlebiidae). ACTA ACUST UNITED AC 2006. [DOI: 10.1002/ps.2780440312] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Integrin alphaEbeta7 is expressed almost exclusively by mucosal T cells and mucosal dendritic antigen-presenting cells (APCs) and is thought to be induced locally by transforming growth factor-beta (TGF-beta). In mice, mRNA for the alphaE subunit was found to be abundant in mucosal T cells but absent from other tissues. Exposure of a T-cell line to TGF-beta strongly up-regulated alphaE mRNA levels within 30 min, and nuclear run-on experiments established that regulation occurred at the level of transcription. The organization of the human alphaE gene and a very closely linked novel gene, ELG, was determined. The alphaE promoter was tested in T cells and fibroblasts and functioned equally well in both cell types and did not confer TGF-beta responsiveness. Regions of the promoter providing enhancer activity and phorbol 12-myristate 13-acetate (PMA) responsiveness were identified by deletion studies. DNAse 1 hypersensitivity analysis of 36 kb of the alphaE gene revealed one hypersensitive site, found only in alphaE+ cells, located near the transcription start points. These results show that, unlike the situation with other integrins, lineage specificity and cytokine responsiveness of alphaE transcription are not conferred by the proximal promoter. Specificity may depend on distant control elements that have not yet been identified.
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17
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Abstract
BACKGROUND The increasing experience with renal allotransplantation has led to continuing development in vascular surgical techniques. These improvements have enabled complex ex vivo renal artery surgery and renal autotransplantation to be performed. The aims of the present study were to describe the results achieved with renal autotransplantation and ex vivo renal artery reconstruction (RAR) at the Newcastle Transplant Unit, John Hunter Hospital, and to review the current indications for such surgery. METHODS A retrospective review was performed of patients who required renal autotransplantation with or without RAR at John Hunter Hospital, between 1991 and 1999. Data were obtained from the Newcastle Transplant Unit and the Medical Record Department of John Hunter Hospital. RESULTS Two patients required ex vivo RAR and renal autotransplantation for severe fibromuscular dysplasia (FMD) complicated by stenoses and renal artery branch aneurysms. The third patient required autotransplantation for bilateral retroperitoneal fibrosis. There was one postoperative complication of pelviureteric junction obstruction that was treated successfully with a temporary ureteric stent. All patients demonstrated normal graft function and were normotensive on follow up, which ranged from 2.5 to 5 years. CONCLUSION The present review confirms the long-term benefits of ex vivo RAR and renal autotransplantation that have been demonstrated by previous studies. In transplant units experienced with this surgery it has been shown to be a successful and durable technique for the treatment of a variety of vascular, urologic and other diseases.
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Affiliation(s)
- C S Cho
- Department of General Surgery, John Hunter Hospital, Newcastle, New South Wales, Australia
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18
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Affiliation(s)
- P W Robinson
- Department of Chemistry, University of Waikato Hospital, Hamilton, New Zealand
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19
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Abstract
Using a BAB design, a token system requiring cooperative interaction was used to change the reading and vocabulary performance of an 18-member class of third-grade hyperactive boys. Four different colored tokens, which could be exchanged for 15 minutes of play on electrovideo games, were earned by successful completion of two tasks that involved learning to read and to use new vocabulary words in sentences, and two tasks in which the student served as a proctor to a student who had not yet completed those tasks. The mean number of tasks completed during the intervention periods rose to over nine times the number completed during reversal. Additionally, the average completion rate for the school district's standardized weekly reading level examinations rose from four to eight fold during the token conditions. All 18 students responded to the token program by increasing their academic performance.
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Wright JE, Hennessy EJ, Bissett RL, Robinson PW. A continuing assessment of wound infection rates from January 1967 to June 1970, with a study of two methods of preoperative skin preparation. Aust N Z J Surg 1973; 42:405-8. [PMID: 4532525 DOI: 10.1111/j.1445-2197.1973.tb06832.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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21
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McCaffrey JF, Robinson PW. Diagnostic femoral arterial puncture. Med J Aust 1966; 1:1116. [PMID: 5943959 DOI: 10.5694/j.1326-5377.1966.tb97659.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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