Mid- to long-term results of the Cone-Conical modular system in revision hip arthroplasty.

BACKGROUND: Modular design in revision hip surgery allows some flexibility intra-operatively to address leg length discrepancy, version, and offset while allowing the surgeon to bypass a deficient proximal femur and achieve axial and rotational stability distally. The purpose of this study was to analyze the mid-term to long-term survival and clinical and radiological outcomes using a conical fluted stem and a cone-shaped hydroxyapatite-coated proximal body "The Cone-Conical modular system (Stryker)" in revision hip surgery. METHODS: We retrospectively reviewed all the patients who underwent hip revision surgery using Cone-Conical modular system between January 2006 and January 2015 at our institution. Seventy patients (72 hips) were included with a mean age of 71.3 years. We had a mean follow-up period of 8.6 years (range 5-15). All patients had a minimum follow-up of five years. A Kaplan-Meier analysis was used to determine the survival of the implant. Functional outcomes were assessed using Oxford Hip Score. Plain radiographs were performed to assess implant fixation and osseointegration. RESULTS: The mean OHS improved significantly from 12 pre-operatively to 34 at the final follow-up (P < .001). The Cone-Conical system survivorship for aseptic loosening as an end point was 100%. The all-cause survivorship was 97.2%. Two hips had revisions for recurrence of infection. CONCLUSIONS: The Cone-Conical femoral modular revision system has demonstrated excellent mid-term to long-term clinical and radiographic results with low failure rate and minimal complications. Longer-term follow-up would be of value to assess the ongoing survival of this implant.

Effectiveness, Patient Satisfaction, and Cost Reduction of Virtual Joint Replacement Clinic Follow-Up of Hip and Knee Arthroplasty.

BACKGROUND: Total hip and knee arthroplasties are increasingly performed operations, and routine follow-up places huge demands on orthopedic services. This study investigates the effectiveness, patients' satisfaction, and cost reduction of Virtual Joint Replacement Clinic (VJRC) follow-up of total hip arthroplasty and total knee arthroplasty patients in a university hospital. VJRC is especially valuable when in-person appointments are not advised or feasible such as during the COVID-19 pandemic. METHODS: A total of 1749 patients who were invited for VJRC follow-up for knee or hip arthroplasty from January 2017 to December 2018 were included in this retrospective study. Patients were referred to VJRC after their 6-week postoperative review. Routine VJRC postoperative review was undertaken at 1 and 7 years and then 3-yearly thereafter. We evaluated the VJRC patient response rate, acceptability, and outcome. Patient satisfaction was measured in a subgroup of patients using a satisfaction survey. VJRC costs were calculated compared to face-to-face follow-up. RESULTS: The VJRC had a 92.05% overall response rate. Only 7.22% required further in-person appointments with only 3% being reviewed by an orthopedic consultant. VJRC resulted in an estimated saving of £42,644 per year at our institution. The patients' satisfaction survey showed that 89.29% of the patients were either satisfied or very satisfied with VJRC follow-up. CONCLUSION: VJRC follow-up for hip and knee arthroplasty patients is an effective alternative to in-person clinic assessment which is accepted by patients, has high patient satisfaction, and can reduce the cost to both health services and patients.

Split and partially entwined sciatic nerve following closed reduction of a dislocated hip prosthesis.

We present a case of split and partially entwined sciatic nerve by a femoral prosthesis following closed reduction of a dislocated hip replacement. This complication is very rare and there are only few cases reported in the literature, with even less accompanied by supporting MRI. We present MRI features of a split and partially entwined sciatic nerve around a hip prosthesis.

Pharmacological thromboprophylaxis to prevent venous thromboembolism in patients with temporary lower limb immobilization after injury: systematic review and network meta-analysis.

BACKGROUND: Thromboprophylaxis has the potential to reduce venous thromboembolism (VTE) following lower limb immobilization resulting from injury. OBJECTIVES: We aimed to estimate the effectiveness of thromboprophylaxis, compare different agents, and identify any factors associated with effectiveness. METHODS: We undertook a systematic review and network meta-analysis (NMA) of randomized trials reporting VTE or bleeding outcomes that compared thromboprophylactic agents with each other or to no pharmacological prophylaxis, for this indication. An NMA was undertaken for each outcome or agent used, and a series of study-level network meta-regressions examined whether population characteristics, type of injury, treatment of injury, or duration of thromboprophylaxis were associated with treatment effect. RESULTS: Data from 6857 participants across 13 randomized trials showed that, compared with no treatment, low molecular weight heparin (LMWH) reduced the risk of any VTE (odds ratio [OR]: 0.52; 95% credible interval [CrI]: 0.37-0.71), clinically detected deep vein thrombosis (DVT) (OR: 0.39; 95% CrI: 0.12-0.94) and pulmonary embolism (PE) (OR: 0.16; 95% CrI: 0.01-0.74), whereas fondaparinux reduced the risk of any VTE (OR: 0.13; 95% CrI: 0.05-0.30) and clinically detected DVT (OR: 0.10; 95% CrI: 0.01-0.86), with inconclusive results for PE (OR: 0.40; 95% CrI: 0.01-7.53). CONCLUSIONS: Thromboprophylaxis with either fondaparinux or LMWH appears to reduce the odds of both asymptomatic and clinically detected VTE in people with temporary lower limb immobilization following an injury. Treatment effects vary by outcome and are not always conclusive. We were unable to identify any treatment effect modifiers other than thromboprophylactic agent used.

Thromboprophylaxis in lower limb immobilisation after injury (TiLLI).

Venous thromboembolic disease is a major global cause of morbidity and mortality. An estimated 10 million episodes are diagnosed yearly; over half of these episodes are provoked by hospital admission/procedures and result in significant loss of disability adjusted life years. Temporary lower limb immobilisation after injury is a significant contributor to the overall burden of venous thromboembolism (VTE). Existing evidence suggests that pharmacological prophylaxis could reduce overall VTE event rates in these patients, but the proportional reduction of symptomatic events remains unclear. Recent studies have used different pharmacological agents, dosing regimens and outcome measures. Consequently, there is wide variation in thromboprophylaxis strategies, and international guidelines continue to offer conflicting advice for clinicians. In this review, we provide a summary of recent evidence assessing both the clinical and cost effectiveness of thromboprophylaxis in patients with temporary immobilisation after injury. We also examine the evidence supporting stratified thromboprophylaxis and the validity of widely used risk assessment methods.

Different strategies for pharmacological thromboprophylaxis for lower-limb immobilisation after injury: systematic review and economic evaluation.

BACKGROUND: Thromboprophylaxis can reduce the risk of venous thromboembolism (VTE) during lower-limb immobilisation, but it is unclear whether or not this translates into meaningful health benefit, justifies the risk of bleeding or is cost-effective. Risk assessment models (RAMs) could select higher-risk individuals for thromboprophylaxis. OBJECTIVES: To determine the clinical effectiveness and cost-effectiveness of different strategies for providing thromboprophylaxis to people with lower-limb immobilisation caused by injury and to identify priorities for future research. DATA SOURCES: Ten electronic databases and research registers (MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effects, the Cochrane Central Register of Controlled Trials, Health Technology Assessment database, NHS Economic Evaluation Database, Science Citation Index Expanded, ClinicalTrials.gov and the International Clinical Trials Registry Platform) were searched from inception to May 2017, and this was supplemented by hand-searching reference lists and contacting experts in the field. REVIEW METHODS: Systematic reviews were undertaken to determine the effectiveness of pharmacological thromboprophylaxis in lower-limb immobilisation and to identify any study of risk factors or RAMs for VTE in lower-limb immobilisation. Study quality was assessed using appropriate tools. A network meta-analysis was undertaken for each outcome in the effectiveness review and the results of risk-prediction studies were presented descriptively. A modified Delphi survey was undertaken to identify risk predictors supported by expert consensus. Decision-analytic modelling was used to estimate the incremental cost per quality-adjusted life-year (QALY) gained of different thromboprophylaxis strategies from the perspectives of the NHS and Personal Social Services. RESULTS: Data from 6857 participants across 13 trials were included in the meta-analysis. Thromboprophylaxis with low-molecular-weight heparin reduced the risk of any VTE [odds ratio (OR) 0.52, 95% credible interval (CrI) 0.37 to 0.71], clinically detected deep-vein thrombosis (DVT) (OR 0.40, 95% CrI 0.12 to 0.99) and pulmonary embolism (PE) (OR 0.17, 95% CrI 0.01 to 0.88). Thromboprophylaxis with fondaparinux (Arixtra®, Aspen Pharma Trading Ltd, Dublin, Ireland) reduced the risk of any VTE (OR 0.13, 95% CrI 0.05 to 0.30) and clinically detected DVT (OR 0.10, 95% CrI 0.01 to 0.94), but the effect on PE was inconclusive (OR 0.47, 95% CrI 0.01 to 9.54). Estimates of the risk of major bleeding with thromboprophylaxis were inconclusive owing to the small numbers of events. Fifteen studies of risk factors were identified, but only age (ORs 1.05 to 3.48), and injury type were consistently associated with VTE. Six studies of RAMs were identified, but only two reported prognostic accuracy data for VTE, based on small numbers of patients. Expert consensus was achieved for 13 risk predictors in lower-limb immobilisation due to injury. Modelling showed that thromboprophylaxis for all is effective (0.015 QALY gain, 95% CrI 0.004 to 0.029 QALYs) with a cost-effectiveness of £13,524 per QALY, compared with thromboprophylaxis for none. If risk-based strategies are included, it is potentially more cost-effective to limit thromboprophylaxis to patients with a Leiden thrombosis risk in plaster (cast) [L-TRiP(cast)] score of ≥ 9 (£20,000 per QALY threshold) or ≥ 8 (£30,000 per QALY threshold). An optimal threshold on the L-TRiP(cast) receiver operating characteristic curve would have sensitivity of 84-89% and specificity of 46-55%. LIMITATIONS: Estimates of RAM prognostic accuracy are based on weak evidence. People at risk of bleeding were excluded from trials and, by implication, from modelling. CONCLUSIONS: Thromboprophylaxis for lower-limb immobilisation due to injury is clinically effective and cost-effective compared with no thromboprophylaxis. Risk-based thromboprophylaxis is potentially optimal but the prognostic accuracy of existing RAMs is uncertain. FUTURE WORK: Research is required to determine whether or not an appropriate RAM can accurately select higher-risk patients for thromboprophylaxis. STUDY REGISTRATION: This study is registered as PROSPERO CRD42017058688. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

People who have their leg immobilised in a plaster cast or brace following an injury are at risk of developing a blood clot. Sometimes the clot can break up and lodge in the lungs, which can make the person seriously ill. Drugs that thin the blood (anticoagulants) can reduce the risk of blood clots, but they carry a small risk of serious bleeding. This study analysed all published trials of anticoagulants for people with leg immobilisation and found that, without treatment, there was a 1­2% risk of a serious blood clot. This risk was roughly halved by using anticoagulant treatment. These estimates were used in a simulation model of patient treatment and it was found that the benefit of anticoagulants in reducing blood clots (in terms of length and quality of life) outweighed the risks of bleeding. Next, all published studies of risk assessment tools were analysed. Risk assessment tools can be used to predict who is most likely to get a blood clot. There were only a few studies and they had significant weaknesses. The risk assessment tools in the simulation model were evaluated and it was found that the most cost-effective approach was to use a risk assessment tool to select approximately half of the patients for treatment (those at higher risk), while not treating those at lower risk. Treating only the higher-risk patients would be a cost-effective use of NHS resources, compared with treating nobody. Treating everybody, compared with just treating higher-risk patients, would improve outcomes for some patients but would not be a cost-effective use of NHS resources. This study suggests that anticoagulant drugs are an effective and potentially cost-effective way of preventing blood clots in people with leg immobilisation due to injury. Research is needed to determine whether or not risk assessment tools can accurately predict who needs anticoagulant drugs and who does not.

Tritanium Acetabular Cup in Revision Hip Replacement: A Six to Ten Years of Follow-Up Study.

BACKGROUND: The use of highly porous acetabular components has shown to produce good results in revision acetabular surgery. Their surface characteristics enhance initial fixation and bone ingrowth which are prerequisites for adequate osseointegration. The purpose of this study is to analyze the mid-term to long-term survival, clinical and radiological outcomes using the Tritanium cup (Stryker, Mahwah, NJ) in revision hip surgery. METHODS: This is a retrospective review of all patients who underwent acetabular revision surgery using "Tritanium revision cup" between April 2007 and November 2010 at our institution. Sixty-two patients were included with a mean age of 67.5 years (32-86). According to Paprosky classification, 10 patients had type I defect, 8 had type IIA, 27 had type IIB, 7 had type IIC, and 10 suffered from type IIIA defect. A Kaplan-Meier analysis was used to determine the survival of the cup. Functional outcomes were assessed using Oxford Hip Score. Plain radiographs were performed to assess implant fixation and osseointegration. RESULTS: The acetabular cup aseptic survivorship was 98.4% at a mean follow-up of 87.6 months. The mean Oxford Hip Score improved from 14.5 (3-31) preoperatively to 38.5 (12-48) at the final follow-up. Two cups were revised (3.2%): 1 for aseptic loosening and 1 for infection. CONCLUSION: Tritanium revision acetabular cup has shown excellent mid-term to long-term clinical and radiographic results with low failure rate and minimal complications. Longer term follow-up would be of value to assess the ongoing survival of this implant construct.

Mid-Term Results of Graft Augmentation Prosthesis II Cage and Impacted Allograft Bone in Revision Hip Arthroplasty.

BACKGROUND: Several techniques have been described for management of severe acetabular bone defects during revision hip surgery including reconstructive cages. The purpose of this study is to analyze the survival and the mid-term clinical and radiological outcome using the Graft Augmentation Prosthesis (GAP II cage) (Stryker Orthopaedics, Mahwah, NJ) in addition to impaction grafting for acetabular defects in revision hip surgery. METHODS: This is a retrospective review of all patients who underwent acetabular revision hip replacement using GAP II cage and impaction bone grafting between 2009 and 2013 at our institution. Twenty-six patients were included with a mean age of 71 years (49-91). According to Paprosky classification, 2 patients had type IIB defect, 4 had type IIC, and 12 had type IIIA, while 8 suffered from type IIIB defect. The clinical outcome was assessed using Oxford Hip Score. Plain radiographs were used to assess preoperative bone loss, postoperative implant migration, and the incorporation of the bone graft to host bone. RESULTS: The average Oxford Hip Score improved from 11.3 (2-22) preoperatively to 32.2 (20-48) postoperatively. The revision free survivorship of this construct was 100% at mean follow-up of 49 months (30-78). Three hips had radiological failure of the implant with no clinical consequences. CONCLUSION: The use of GAP II cage with impaction bone grafting to reconstruct severe acetabular defects had encouraging mid-term results with low failure rate. Graft incorporation with restoration of bone stock may be beneficial should further revision surgery be needed.

Revision knee arthroplasty using a distal femoral replacement prosthesis for periprosthetic fractures in elderly patients.

PURPOSE: Distal femoral periprosthetic fractures above a total knee replacement in elderly patients are technically challenging to treat. Bone quality is often poor, the fractures comminuted, and post-operative mobilisation is difficult. This study assesses the clinical, radiological and functional outcome of revision knee distal femoral replacement (DFR) in these fractures. METHODS: We identified 14 patients over 70 years of age (70-94) who underwent DFR for periprosthetic fractures above a knee replacement. All the 14 fractures were classified as Su type III. Clinical and radiological records were retrospectively reviewed. The mean of clinical follow-up was 27 months (8-46). Functional outcome was assessed using Oxford Knee Score and EQ-5D (UK English Version) score at a mean time of 35 months (20-65). The Knee Society patient category score was also evaluated. RESULTS: The median post-operative knee flexion was 100° (range 90°-135°). Nine patients (64%) returned to their pre-fracture level of mobility or better. The median post-operative Oxford Knee Score was 27 (range 4-40). The median EQ-5D was 11 (range 6-12). Cognitive impairment negatively impacted the functional outcome in four patients. One patient died early post-operatively, and two patients had complications. CONCLUSIONS: DFR led to satisfactory outcome in our patients with a relatively low complication rate. In our experience, revision knee distal femoral replacement is an appropriate method to treat elderly patients who sustained periprosthetic Su et al. type III distal femoral fractures in association with poor bone stock, caused by osteoporosis and/or comminution.

Achievement Of Primary Stability Using 3D-CT Guided Custom Design Femoral Stems In Patients With Proximal Femoral Deformity : EBRA-FCA Analysis.

Hip replacement in patients with proximal femoral deformity and end stage arthrosis is technically challenging. The purpose of this study was to measure the subsidence rate of custom femoral stems using EBRA-Femoral Component Analysis (FCA) software, as an indicator of achievement of primary stability. We retrospectively reviewed 14 hips in 12 consecutive patients who underwent this procedure between June 2008 and Feb. 2011. There were 7 males and 5 females with a mean age 41 years (22-60). The primary diagnosis in the majority of the cases was Perthes and DDH with secondary osteoarthritis. The average follow up period was 36 ± 10 months (19-51 months). Average subsidence was the 0.96 mm ± 0.95mm (0- 2.9 mm). All patients had signs of osteointegration at the metaphyseal level. We conclude that the 3D-CT guided custom made femoral stem produces reliable proximal 'fit and fill' and osteointegration without the need of a corrective osteotomy in patients with proximal femoral deformity but long term studies are needed to assess the performance of this femoral stem.

Management of Vancouver B2 and B3 Periprosthetic Proximal Femoral Fractures by Distal Locking Femoral Stem (Cannulok) in Patients 75 Years and Older.

BACKGROUND: Periprosthetic fracture following total hip arthroplasty is a significant problem faced by hip surgeons, and its management in elderly patients remains a considerable challenge. METHODS: We retrospectively reviewed 28 Vancouver B2 and B3 periprosthetic femoral fractures (PFF) treated with revision of the femoral stems by distally locked, hydroxyapatite-coated uncemented stems (Cannulok). Patients were aged 75 years or older at the time of surgery. RESULTS: The mean follow-up was 44.6 months (range, 24-102). The mean postoperative Oxford hip score was 30.1 (range, 10-46). The rate of fracture union was 95.8%, and the survivorship of the stem was 100% at the end of follow-up. CONCLUSION: The management of PFF in elderly is associated with increased postoperative morbidity and mortality. The use of a distally locked, hydroxyapatite-coated femoral stem is a valid option for the treatment of PFF to achieve fracture union with a low rate of revision.

Tell Me Your Story: A Pilot Narrative Medicine Curriculum During the Medicine Clerkship.

BACKGROUND: Narrative medicine educational interventions may enhance patient-centered care, yet most educational interventions do not involve actual patient-provider interactions, nor do they assess narrative competence, a key skill for its practice. An experiential narrative medicine curriculum for medical students was developed and piloted. AIMS: The purpose of the study was to develop narrative competence, practice attentive listening, and stimulate reflection. PARTICIPANTS/SETTING: Participants were third-year medicine clerkship students. PROGRAM DESCRIPTION: The curriculum involved 1) an introductory session, 2) a patient storytelling activity, and 3) a group reflection session. For the storytelling activity, students elicited illness narratives in storytelling form from patients, listened attentively, wrote their versions of the story, and then read them back to patients. PROGRAM EVALUATION: Five student focus groups were conducted between July 2011 and March 2012 (n = 31; 66%) to explore students' experiences, student-patient dynamics, challenges, and what they learned. Patient interviews (n = 17) on their experience were conducted in January 2013. Thematic analysis of the audiotaped stories of ten patients and corresponding student-written stories helped gauge narrative competence. DISCUSSION: The curriculum was found to be feasible and acceptable to both patients and students. Some patients and students were profoundly moved. Ongoing focus groups resulted in continual process improvement. Students' stories showed attainment of narrative competence.

Cambridge community Optometry Glaucoma Scheme.

BACKGROUND: With a higher life expectancy, there is an increased demand for hospital glaucoma services in the United Kingdom. DESIGN: The Cambridge community Optometry Glaucoma Scheme (COGS) was initiated in 2010, where new referrals for suspected glaucoma are evaluated by community optometrists with a special interest in glaucoma, with virtual electronic review and validation by a consultant ophthalmologist with special interest in glaucoma. PARTICIPANTS: 1733 patients were evaluated by this scheme between 2010 and 2013. METHODS: Clinical assessment is performed by the optometrist at a remote site. Goldmann applanation tonometry, pachymetry, monoscopic colour optic disc photographs and automated Humphrey visual field testing are performed. A clinical decision is made as to whether a patient has glaucoma or is a suspect, and referred on or discharged as a false positive referral. The clinical findings, optic disc photographs and visual field test results are transmitted electronically for virtual review by a consultant ophthalmologist. MAIN OUTCOME MEASURES: The number of false positive referrals from initial referral into the scheme. RESULTS: Of the patients, 46.6% were discharged at assessment and a further 5.7% were discharged following virtual review. Of the patients initially discharged, 2.8% were recalled following virtual review. Following assessment at the hospital, a further 10.5% were discharged after a single visit. CONCLUSIONS: The COGS community-based glaucoma screening programme is a safe and effective way of evaluating glaucoma referrals in the community and reducing false-positive referrals for glaucoma into the hospital system.

The accuracy and reliability of pre-operative templating in revision total knee arthroplasty. A comparison of analogue and digital methods.

AIMS: To determine whether the size of the prostheses used in revision knee arthroplasty may be accurately and reproducibly predicted using analogue or digital pre-operative templating techniques. METHODS: Pre-operative radiographs were templated using analogue radiographs and acetate templates, digital radiographs and acetate templates and digital radiographs and digital templating software. RESULTS: Overall accuracy of predicting the size of implant used at surgery was 44%. There was no significant difference in the accuracy of the various templating techniques (p = 0.098). CONCLUSIONS: Templating in revision knee arthroplasty is neither of suitable accuracy nor reliability enough to safely recommend its use for implant size prediction.

Cambridgeshire cataract shared care model: community optometrist-delivered postoperative discharge scheme.

BACKGROUND/AIMS: To evaluate a community optometrist-delivered postoperative discharge scheme in patients who underwent same day discharge from the hospital eye service (HES) following cataract surgery. METHODS: A service-level agreement (SLA) was agreed between the HES, primary care trust and community optometrists in Cambridgeshire regarding community follow-up after cataract surgery. Patients undergoing uncomplicated surgery with no significant ocular comorbidity were eligible for same day discharge to community optometrists. Feedback return rate and unintended medical interventions were assessed using an electronic medical record system. RESULTS: Over a 23-month period, a total of 1492 of 2461 (60.6%) Cambridgeshire patients were discharged to the community on the day of cataract surgery. Complete postoperative feedback was available in 96.85% of these patients. Uneventful postoperative recovery was recorded in 93.77% of patients with 2.95% of patients re-referred. Rates of cystoid macular oedema, uveitis and raised intraocular pressure were 0.6%, 1% and 0.1%, respectively. No patients had sight-threatening complications in this study. CONCLUSIONS: Postcataract surgery follow-up by community optometrists provides the advantages of care closer to home and avoids unnecessary hospital visits for patients undergoing uncomplicated cataract surgery.

Midterm results with Birmingham Hip Resurfacing/Synergy stem modular metal-on-metal total hip arthroplasty.

Large head modular metal-on-metal total hip replacement (MoMTHR) has been shown to have increased revision rates in the National joint registry and in literature. We reviewed 41 consecutive patients with 44 hips who had large head MoM THR using a Birmingham Hip Resurfacing (BHR) cup/Synergy stem combination between June 2005 and Nov 2009 with a mean followup of 59.5 months. In this series we had a revision rate of 6.8% (3/44) for adverse reaction to metal debris (ARMD), persistent groin pain and instability. Kaplan-Meier analysis showed a mean cumulative survival rate of 79.2% (95% CI: 75.5%-82.9%) In addition there is a subset of 5/44 patients (113%) with mild grade groin pain who may need revision in the future. Based on these findings, we do not recommend performance of large head MoMTHR in the future.

Repair of rectus femoris rupture with LARS ligament.

The rectus femoris muscle is the most frequently involved quadriceps muscle in strain pathologies. The majority of quadriceps muscle belly injuries can be successfully treated conservatively and even significant tears in the less active and older population, non-operative management is a reasonable option. The authors report the delayed presentation of a 17-year-old male who sustained an injury to his rectus femoris muscle belly while playing football. This young patient did not recover the functional outcome required to get back to running and participating in sport despite 15 months of physiotherapy and non-operative management. Operative treatment using the ligament augmentation and reconstruction system ligament to augment Kessler repair allowed immediate full passive flexion of the knee and an early graduated physiotherapy programme. Our patient was able to return to running and his previous level of sport without any restrictions.

Crystallin distribution patterns in Litoria infrafrenata and Phyllomedusa sauvagei lenses.

The eye lens remains transparent because of soluble lens proteins known as crystallins. For years γ-crystallins have been known as the main lens proteins in lower vertebrates such as fish and amphibians. The unique growth features of the lens render it an ideal structure to study ageing; few studies have examined such changes in anuran lenses. This study aimed to investigate protein distribution patterns in Litoria infrafrenata and Phyllomedusa sauvagei species. Lenses were fractionated into concentric layers by controlled dissolution. Water-soluble proteins were separated into high (HMW), middle (MMW) and low molecular weight (LMW) fractions by size-exclusion HPLC and constituents of each protein class revealed by 1DE and 2DE. Spots were selected from 2DE gels on the basis of known ranges of subunit molecular weights and pH ranges and were identified by MALDI-TOF/TOF MS following trypsin digestion. Comparable lens distribution patterns were found for each species studied. Common crystallins were detected in both species; the most prominent of these was γ-crystallin. Towards the lens centre, there was a decrease in α- and ß-crystallin proportions and an increase in γ-crystallins. Subunits representing taxon-specific crystallins demonstrating strong sequence homology with ζ-crystallin/quinone oxidoreductase were found in both L. infrafrenata and P. sauvagei lenses. Further work is needed to determine which amphibians have taxon-specific crystallins, their evolutionary origins, and their function.

Position of the popliteal artery in revision total knee arthroplasty.

BACKGROUND: Injury to the popliteal artery during total knee arthroplasty is a devastating complication. This topic was studied previously prior to primary total knee arthroplasty. This study aims to demonstrate the position of the popliteal artery in patients prior to revision total knee replacement. METHODS: The ultrasound scan results of the position of the popliteal artery in 23 patients were reviewed. The implant/artery distance at different levels was measured with the knee in extension and 70°-90° of flexion. RESULTS: There was no significant difference in the artery position at the level of the tibial metal base plate (the most critical site) on moving the knee from extension to flexion (P = 0.26). However, the implant/artery distance was found to increase on moving from extension to flexion in relation to the femoral component at the joint line (69%), as well as 15 mm below the level of the tibial base plate representing 69.3%. There was a significant difference at 15 mm above the joint line, where the distance was found to be increased in 84.6% of cases (P = 0.019). CONCLUSION: This study has shown that in a revision knee situation, there is no reliable fall back of the popliteal artery in knee flexion; in fact, implant/artery distance may be decreased and caution must be exercised throughout the procedure. It may be worth considering either ultrasound or arteriography in selected cases.