Gluteal Tendinopathy is a poorly understood condition that predominantly affects post-menopausal women. It causes lateral hip pain, worse when lying on the affected side or when walking up a hill or stairs. It has been labelled ˜Greater Trochanteric Pain Syndrome” a name that recognises the lack of understanding of the condition. Surgical reconstruction of the gluteal cuff is well established and has been undertaken numerous times over the last 16 years by the senior author (AJL). However, the quality of collagen in the tendons can be very poor and this leads to compromised results. We present the results of gluteal cuff reconstruction combined with augmentation using a bioinductive implant. 14 patients (11 female, 3 male; mean age 74.2 ± 6.3 years) with significant symptoms secondary to gluteal tendinopathy that had failed conservative treatment (ultrasound guided injection and structured physiotherapy) underwent surgical reconstruction by the senior author using an open approach. In all cases the iliotibial band was lengthened and the trochanteric bursa excised. The gluteal cuff was reattached using Healicoil anchors (3–5×4.75mm anchors; single anchors but double row repair) and then augmented using a Regeneten patch. Patients were mobilised fully weight bearing post-operatively but were asked to use crutches until they were no longer limping. All had structured post-surgery rehabilitation courtesy of trained physiotherapists. There were no post-operative complications and all patients reported an improvement in pain levels (Visual Analogue Scale 7.8 pre-op; 2.6 post-op) and functional levels (UCLA Activity Score 3.5 pre-op; 7.1 post-op) at 6 months post surgery. Surgery for gluteal tendinopathy produces good outcomes and the use of Regeneten as an augment for poor quality collagen is seemingly a safe, helpful addition. Further comparative studies would help clarify this.
Knee arthroscopy can be used for ligamentous repair, reconstruction and to reduce burden of infection. Understanding and feeling confident with knee arthroscopy is therefore a highly important skillset for the orthopaedic surgeon. However, with limited training or experience, furthered by reduced practical education due to COVID-19, this skill can be under-developed amongst trainee surgeons. At a single institution, ten junior doctors (FY1 to CT2), were recruited as a part of a five, two-hour session, training programme utilising the Simbionix® ARTHRO Mentor knee arthroscopy simulator, supplemented alongside educational guidance with a consultant orthopaedic knee surgeon. All students had minimal to no levels of prior arthroscopic experience. Exercises completed included maintaining steadiness, image centring and orientation, probe triangulation, arthroscopic knee examination, removal of loose bodies and meniscectomy. Pre and post experience questionnaires and quantitative repeat analysis on simulation exercises were undertaken to identify levels of improvement.Introduction
Methods
Knee arthroscopy can be used for ligamentous repair, reconstruction and to reduce burden of infection. Understanding and feeling confident with knee arthroscopy is therefore a highly important skillset for the orthopaedic surgeon. However, with limited training or experience, furthered by reduced practical education due to COVID-19, this skill can be under-developed amongst trainee surgeons. At a single institution, ten junior doctors (FY1 to CT2), were recruited as a part of a five, two-hour session, training programme utilising the Simbionix® ARTHRO Mentor knee arthroscopy simulator, supplemented alongside educational guidance with a consultant orthopaedic knee surgeon. All students had minimal to no levels of prior arthroscopic experience. Exercises completed included maintaining steadiness, image centering and orientation, probe triangulation, arthroscopic knee examination, removal of loose bodies, and meniscectomy. Pre and post-experience questionnaires and quantitative repeat analysis on simulation exercises were undertaken to identify levels of improvement.Abstract
Introduction
Methods
United Classification System (UCS) B2 and B3 periprosthetic fractures in total hip arthroplasties (THAs) have been commonly managed with modular tapered stems. No study has evaluated the use of monoblock fluted tapered titanium stems for this indication. This study aimed to evaluate the effects of a monoblock stems on implant survivorship, postoperative outcomes, radiological outcomes, and osseointegration following treatment of THA UCS B2 and B3 periprosthetic fractures. A retrospective review was conducted of all patients who underwent revision THA (rTHA) for periprosthetic UCS B2 and B3 periprosthetic fracture who received a single design monoblock fluted tapered titanium stem at two large, tertiary care, academic hospitals. A total of 72 patients met inclusion and exclusion criteria (68 UCS B2, and four UCS B3 fractures). Primary outcomes of interest were radiological stem subsidence (> 5 mm), radiological osseointegration, and fracture union. Sub-analysis was also done for 46 patients with minimum one-year follow-up.Aims
Methods
Prosthetic joint infections (PJI) are one of the most devastating complications of joint replacement surgery. They are associated with significant patient morbidity and carry a significant economic cost to treat. The management of PJI varies from antibiotic suppression, debridement, antibiotics, and implant retention (DAIR) procedures through to single/multiple stage revision procedures. Concerns have been raised recently in relation to the rising number of revision arthroplasty procedures that are being undertaken in relation to infection. This database aims to collect data on all PJIs that have been managed in the Australian Capital Territory (ACT) region. This will allow us to investigate the microbial trends, outcomes of surgical intervention and patient outcomes within our local population. This database will incorporate diagnostic, demographic, microbiological and treatment information in relation to local PJI cases. The data will be collated from the local infectious diseases database, hospital medical records, and where available the Australian Orthopaedic Association National Joint Replacement Registry Data. The first 100 cases of PJI were assessed. 76% were defined as being acute. 56% of the patients received antibiotics prior to their diagnosis however only 3% were culture negative. 89% were monomicrobial and 11% polymicrobial. The intended management strategy was a DAIR in 38% of patients and a 2-stage revision in 12% of cases. The intended management strategy was successful in 46% of the patients. The ACT is uniquely placed to analyze and create a local PJI database. This will allow us to guide further treatment and local guidelines in terms of management of these complex patients.
Staphylococcus aureus is the most frequently isolated organism in periprosthetic joint infections. The mechanism by which synovial fluid (SF) kills bacteria has not yet been elucidated, and a better understanding of its antibacterial characteristics is needed. We sought to analyze the antimicrobial properties of exogenous copper in human SF against S. aureus. SF samples were collected from patients undergoing total elective knee or hip arthroplasty. Different S. aureus strains previously found to be sensitive and resistant, UAMS-1 and USA300 WT, respectively, were used. We performed in-vitro growth and viability assays to determine the capability of S. aureus to survive in SF with the addition of 10µM of copper. We determined the minimum bactericidal concentration of copper (MBC-Cu) and evaluated the sensitivity to killing, comparing WT and CopAZB-deficient USA300 strains. UAMS-1 evidenced a greater sensitivity to SF when compared to USA300 WT, at 12 (p=0.001) and 24 hours (p=0.027). UAMS-1 significantly died at 24 hours (p=0.017), and USA300 WT survived at 24 hours. UAMS-1 was more susceptible to the addition of copper at 4 (p=0.001), 12 (p=0.005) and 24-hours (p=0.006). We confirmed a high sensitivity to killing with the addition of exogenous copper on both strains at 4 (p=0.011), 12 (p=0.011), and 24 hours (p=0.011). Both WT and CopAZB-deficient USA300 strains significantly died in SF, evidencing a MBC-Cu of 50µM against USA300 WT (p=0.011). SF has antimicrobial properties against S. aureus, and UAMS-1 was more sensitive than USA300 WT. The addition of 10µM of copper was highly toxic for both strains, confirming its bactericidal effect. We evidenced CopAZB-proteins involvement in copper effluxion by demonstrating the high sensitivity of the mutant strain to lower copper concentrations. Thus, we propose CopAZB-proteins as potential targets and the use of exogenous copper as possible treatment alternatives against S. aureus.
There is a need for non-radiographic, objective outcome measures for children with Adolescent Idiopathic Scoliosis (AIS). Standing balance and stability is altered in children with AIS. The Margin of Stability (MoS) has been used to compare gait stability in clinical populations. Our objective was to compare the MoS in anterior-posterior (MoSAP) and mediolateral (MoSML) directions in girls with AIS to Controls. Girls with AIS and healthy girls walked at three speeds on an instrumented treadmill wearing retroreflective markers, surrounded by motion capture cameras. The MoSAP/ML was calculated at left and right heel strike. Data was processed in Visual 3D. A two-way ANOVA was used to compare MoSAP/ML between group, speed and the interaction between group and speed. Pearson's correlation coefficient was used to compare the MoS to Cobb angle. Statistical significance was accepted when A priori power analysis suggested 12 participants per group. Three Cases and four Controls were recruited. Girls with AIS all had right-sided main thoracic curves (Lenke type 1a, 61.3° ± 10.0°). MoSAP was significantly bigger for Cases compared to Controls on the left ( Girls with Lenke type 1a AIS are more stable in the AP direction and less stable in the ML direction than Controls during treadmill walking. AP stability increases and ML stability decreases with increasing Cobb angle. This research suggests that the MoS could be used as an outcome measure for children with AIS. Continued work is required to increase the power of this study. Further work could consider these changes during walking overground, measuring an MoS or MoS-like measure using a wearable device, and in different curve types.
Success treating AIS with bracing is related to time worn and scoliosis severity. Temperature monitoring can help patients comply with their orthotic prescription. Routinely collected temperature data from the start of first brace treatment was reviewed for 14 patients. All were female with an average age of 12.4 years (range 10.3–14.6) and average 49o Cobb angle (30–64). Our current service recommendation is brace wear for 20 hours a day. Patients complied with this prescription 38.0% of the time, with four patients averaging this or more. Average brace wear was 16.3 hours per day (3.5–22.2). There were 13 patients who had completed brace treatment. The majority had surgery (7/13; 54%) or were considering surgery (1/13; 8%). There were 5 who did not wish surgery at discharge (5/13; 38%); 1 achieved a 40o Cobb angle, with 4 larger (53o;53o;54o;68o). The Bracing in AIS Trial (BrAIST) study measured “success” as less than a 50o Cobb angle, so using this metric our cohort has had a single “success”. Temperature monitors allowed an analysis of when patients were achieving their brace wear. When comparing daywear (8am-8pm) to nightwear (8pm-8am), patients wore their brace an average of 7.6 hours a day (2.5–11.2) and 8.7 hours a night (0.4–11.5). We conclude the minority of our patients comply with our current 20 hour orthotic prescription. The “success” of brace treatment is lower than comparison studies despite higher average compliance but starting with a larger scoliosis. Brace wear is achieved during both the day and night.
This study investigates the effects of intra-articular injection of adipose-derived mesenchymal stem cells (AdMSCs) and platelet-rich plasma (PRP) on lameness, pain, and quality of life in osteoarthritic canine patients. With informed owner consent, adipose tissue collected from adult dogs diagnosed with degenerative joint disease was enzymatically digested and cultured to passage 1. A small portion of cells (n = 4) surplus to clinical need were characterized using flow cytometry and tri-lineage differentiation. The impact and degree of osteoarthritis (OA) was assessed using the Liverpool Osteoarthritis in Dogs (LOAD) score, Modified Canine Osteoarthritis Staging Tool (mCOAST), kinetic gait analysis, and diagnostic imaging. Overall, 28 joints (25 dogs) were injected with autologous AdMSCs and PRP. The patients were followed up at two, four, eight, 12, and 24 weeks. Data were analyzed using two related-samples Wilcoxon signed-rank or Mann-Whitney U tests with statistical significance set at p < 0.05.Aims
Methods
Anterior cruciate ligament (ACL)-retaining total knee arthroplasty (TKA) has been associated with more physiologic motion patterns, more normal knee kinematics, and higher patient preference than ACL-sacrificing implant designs. However, it remains unclear how many osteoarthritic patients can be expected to have an intact ACL at the time of surgery in order to undergo ACL-retaining TKA. A systematic literature review was performed in November 2018 using the PubMed and EMBASE databases. Papers written in English, with more than 10 adult patients relevant to the research question were included, whereas cadaveric, revision, animal and simulation studies and conference abstracts were excluded. Data on ACL retention during intraoperative assessment or MRI scans were extracted and analysed using proportional meta-analyses. Twenty-six eligible publications (4167 knees) were included: 20 using intraoperative assessment, 4 using MRI, and 2 using both. Intraoperative assessment of the ACL during TKA showed that the ligament was present in 78% (95% confidence interval [CI]: 72–84%) and intact in 55% (95% CI: 45–65%) of the patients examined. MRI scans revealed higher percentages of ACL presence and intactness than intraoperative assessment, with 91% (95% CI: 79–96%) of the ACL being present and 68% (95% CI: 28–92%) intact. Fewer studies reported on MRI results compared to studies reporting on the intraoperative status of the ACL. In conclusion, intraoperative assessment suggests that over half of the osteoarthritic patients have an intact ACL at the time of TKA surgery, some of whom may qualify for bicruciate-retaining arthroplasty. For any figures or tables, please contact authors directly.
Renal impairment following major surgery is a formidable complication. There is recent evidence suggesting increasing risk of progression to chronic kidney disease and mortality after transient renal impairment. We aimed to evaluate the impact of pre-operative comorbidities on long-term outcomes of renal-function following hip arthroplasty. Patients listed for hip arthroplasty were pre-assessed according to the Charlson-Comorbidity-index (CCI) in May 2017. Demographic data, established risk factors and preoperative renal-function were collected. Pre-existing renal dysfunction was classified using KDIGO CKD criteria. RIFLE AKIN scores were used to document post-operative renal impairment based on 7-day serum creatinine. Renal function was assessed at 30 day and 1 year. Risk for early and long-term-complications were determined by univariate and multivariate analysis. Mortality and kidney-disease-progression were estimated using Kaplan Meier plotsIntroduction
Method
The purpose of this study was to compare pre-operative acetabular cup parameters using this novel dynamic imaging sequence to the Lewinnek safe zone We retrospectively reviewed 350 consecutive primary THAs that underwent dynamic pre-operative acetabular cup planning utilizing a pre-operative CT scan to capture the individual's hip anatomy, followed by standing (posterior pelvic tilt), sitting (anterior pelvic tilt), and supine X-rays. Using these inputs, we modeled an optimal cup position for each patient. Radiographic parameters including inclination, anteversion, pelvic tilt, pelvic incidence, and lumbar flexion were analyzed.Introduction
Methods
Adductor canal blocks offer an alternative to femoral nerve block for postoperative pain relief in knee arthroplasty. They may reduce the risk of quadriceps weakness, allowing earlier mobilisation of patients postoperatively. However, little is known about the effect of a tourniquet on the distribution of local anaesthetic in the limb. Ultrasound-guided adductor canal blocks were performed on both thighs of five human cadavers. Left and right thighs of each cadaver were randomised to tourniquet or no tourniquet for one hour. Iohexol radio-opaque contrast (Omnipaque 350) was substituted for the local anaesthetic for X-Ray imaging. All limbs underwent periodic flexion and extension during this hour to simulate positioning during surgery. The cadavers were refrozen. Fiducial markers were inserted into the frozen tissue. X-rays were obtained in 4 planes (AP, lateral 45° oblique/medial oblique, lateral). University Research Ethics Approval was obtained and cadavers were all pre-consented for research, imaging and photography according to the Anatomy Act (1984). Analysis of radiographs showed contrast distribution in all thighs to be predominantly on the medial aspect of the thighs. The contrast margins were entire and well circumscribed, strongly suggesting it was largely contained within the aponeurosis of the adductor canal. Tourniquets appeared to push the contrast into a narrower and more distal spread along the length of the thigh compared to a more diffuse spread for those without. Proximal spread towards the femoral triangle was reduced in limbs without tourniquets. The results suggest that contrast material may remain within the adductor canal structures during adductor canal blocks. Tourniquets may cause greater distribution of contrast proximally and distally in the thigh, but this does not appear to be clinically significant. Further studies might include radio-stereo photometric analysis using the fiducial markers in the limbs and in vivo studies to show the effect of haemodynamics on distribution.
The mainstay of surgical correction of hallux valgus is first
metatarsal osteotomy, either proximally or distally. We present
a technique of combining a distal chevron osteotomy with a proximal
opening wedge osteotomy, for the correction of moderate to severe
hallux valgus. We reviewed 45 patients (49 feet) who had undergone double osteotomy.
Outcome was assessed using the American Orthopaedic Foot and Ankle
Society (AOFAS) and the Short Form (SF) -36 Health Survey scores.
Radiological measurements were undertaken to assess the correction. The mean age of the patients was 60.8 years (44.2 to 75.3). The
mean follow-up was 35.4 months (24 to 51).Aims
Patients and Methods
Traditional physiotherapy methods utilised in the management of NSCLBP have small effects on pain and disability and this is reflected by data previously collected by the host physiotherapy service. O'Sullivan has validated a novel classification system and matching treatment strategy known as Classification Based–Cognitive Functional Therapy (CB-CFT) for people with NSCLBP. Briefly, CB-CFT is a behavioural and functional management approach to NSCLBP. A recent RCT employing CB-CFT has demonstrated superior outcomes in comparison to traditional physiotherapy methods advocated by clinical practice guidelines. It was unknown if CB-CFT improved outcomes for people with NSCLBP attending an NHS physiotherapy service, therefore an evaluation of practice was proposed. People referred to physiotherapy with NSCLBP were assessed and treated by a physiotherapist trained in the delivery of CB-CFT. Primary outcomes of interest included the Oswestry Disability Index (ODI) and Numerical Pain Rating Scale (NPRS). A retrospective evaluation was performed for sixty-one people referred to physiotherapy with NSCLBP. Statistically significant improvements in disability (ODI p<0.001) and pain (NPRS p<0.001) were demonstrated. 88% of people achieved minimum clinically important change, defined as >10 points for the ODI and 75% of people achieved minimum clinically important change, defined as >2 on NPRS. Mean improvement of 24.7 points for the ODI and 3.0 for NPRS was observed immediately following CB-CFT, demonstrating large effect sizes of 1.56 and 1.21 respectively.Purpose and Background
Methods and Results
NICE guidelines state that every patient should be assessed for their VTE risk on admission to hospital. The aim of this study was to determine whether currently recommended risk assessment tools (Nygaard, Caprini, NICE and Plymouth) can correctly identify the patients at risk. In a consecutive series of over 750 trauma patients treated with cast immobilisation 23 were found to have suffered a VTE. Their notes were retrospectively reviewed to discover how many had been assessed for their VTE risk on admission. Additionally, the 4 most current Risk Assessment Tools were used to retrospectively score the patients for their VTE risk to determine whether they would have been identified as at risk of sVTE, had the RAMs been used at the time. We also identified a matched group of patients in the same cohort who had not suffered a VTE and they were also retrospectively risk assessed.Introduction:
Methods:
Single shot interscalene blocks are an effective analgesic for arthroscopic shoulder surgery. However, patients receiving these blocks are often found to be in significant pain when the block wears off, usually in the late evening or early hours of the morning. Overnight admission is currently routine in our unit, to ensure adequate analgesia can be administered during this period. Recent studies have suggested that adding dexamethasone to the local anaesthetic agent can prolong the duration of the block. We carried out a prospective study to assess whether addition of dexamethasone to brachial plexus blocks could reduce patient's post-operative analgesic demands and allow safe discharge on the same day after surgery. Twenty-six patients undergoing arthroscopic shoulder surgery during a morning theatre list, had ultrasound guided brachial plexus blocks using a mixture of 0.25% bupivacaine 20–30ml with 2–3mg of dexamethasone. All were admitted to the ward afterwards for analgesia and physiotherapy. Pain numerical rating scores (0–10) were recorded at rest in recovery one hour postoperatively by the attending anaesthetist and on active movement of the shoulder joint 24 hours after surgery by the attending physiotherapist. A standardised analgesia regime was prescribed with regular and as required medication, including as required strong opiates. Mean pain scores in recovery were 0.31 and on the morning after surgery were 2.38. Sixteen out of 26 required no further analgesia, with only 3 out of the 10 who did requiring opiates. The use of dexamethasone provides adequate analgesia for a prolonged period for most patients after brachial plexus block for shoulder surgery and does not result in a significant analgesic requirement when the block wears off. This may provide support for avoiding overnight admission in selected patients after arthroscopic shoulder surgery.
Intervention is rare following minimally displaced radial head fractures or positive elbow ‘fat pad’ signs. A pilot study (n=20) found no patient required active treatment after discharge following their first fracture clinic visit. We therefore initiated routine discharge from A&E with an advice sheet, and an ‘open-door policy’ if patients failed to progress. 51 patients were managed by A&E according to this protocol over a six-month period. A standardised assessment of symptoms, satisfaction and functional limitation was completed for 24 patients by phone; average time to follow-up 4.2 months (range 2–9 months). Fourteen (58.4%) reported no pain. The 10 patients (41.6%) with on-going pain reported a median visual analogue score (VAS 0–10) of 0.7 (0–4) at rest, 0.25 (0–4) at night, 3.0 (0–10) carrying heavy objects and 2.75 (0–10) during repetitive movement. 4 of 24 (16.7%) reported minor functional impairment. 3 of 24 (12.5%) patients requested orthopaedic review, but all were satisfied with outcome, seeking reassurance and discharged without any intervention. 3 of 24 (12.5%) were unhappy with their progress, but all had suffered from chronic pain or psychological conditions predating their injury. When offered further review, none of these patients accepted. 22 (91%) were satisfied with their treatment and 23 (95.8%) returned to work and hobbies. This data suggests routine discharge from A&E with advice does not compromise care, as no intervention is usually required beyond advice. These findings have obvious positive clinical and financial implications in streamlining clinical workload.
Lateral malleolar plating is associated with complication rates of up to 30%. The fibular nail is an alternative fixation technique, requiring a minimal incision and tissue dissection, with the potential to reduce the incidence of complications. We reviewed our results of 105 unstable ankle fractures fixed with the Acumed fibular nail between 2002 and 2010. The mean age was 65 years and 72% of patients had significant systemic medical comorbidities. A number of different locking screw configurations were assessed over the study period. A proximal blocking screw resulted in satisfactory stability in 93%, single locking screws in 86%, but nailing without locking in only 66%, leading to the development of our current technique. Of the twenty-one patients treated with this technique there have been no significant complications, and only two superficial wound infections. Good fracture reduction was achieved in all of these patients. The mean physical component SF12, Olerud and Molander and Foot and Ankle Outcome scores were 46, 65 and 83 respectively. The outcomes of unstable ankle fractures managed with the fibular nail are encouraging, with good radiographic and functional outcomes and minimal complications. This technique should be considered in the management of debilitated patients with unstable ankle fractures.
Techniques for fixation of the lateral malleolus have remained essentially unchanged since the 1960s, but are associated with complication rates of up to 30%. The fibular nail is an alternative method of fixation requiring a minimal incision and tissue dissection, and has the potential to reduce complications. We reviewed the results of 105 patients with unstable fractures of the ankle that were fixed between 2002 and 2010 using the Acumed fibular nail. The mean age of the patients was 64.8 years (22 to 95), and 80 (76%) had significant systemic medical comorbidities. Various different configurations of locking screw were assessed over the study period as experience was gained with the device. Nailing without the use of locking screws gave satisfactory stability in only 66% of cases (4 of 6). Initial locking screw constructs rendered between 91% (10 of 11) and 96% (23 of 24) of ankles stable. Overall, seven patients had loss of fixation of the fracture and there were five post-operative wound infections related to the distal fibula. This lead to the development of the current technique with a screw across the syndesmosis in addition to a distal locking screw. In 21 patients treated with this technique there have been no significant complications and only one superficial wound infection. Good fracture reduction was achieved in all of these patients. The mean physical component Short-Form 12, Olerud and Molander score, and AAOS Foot and Ankle outcome scores at a mean of six years post-injury were 46 (28 to 61), 65 (35 to 100) and 83 (52 to 99), respectively. There have been no cases of fibular nonunion. Nailing of the fibula using our current technique gives good radiological and functional outcomes with minimal complications, and should be considered in the management of patients with an unstable ankle fracture.
Doubt has been cast over the accuracy of dermatome charts. This study investigated a large group of patients with known lumbar nerve root compression (NRC), and identified whether their radicular pain corresponded with the predicted distribution on a dermatome chart. The study included 209 patients that presented with lumbar radiculopathy. 106 were confirmed as L5 NRC and 103 as S1 NRC, by MRI. Each patient used an interactive computer assessment program to record their pain on a body map image. The coordinates were then used to compare the sensory distribution to a standard dermatome chart.Background
Methods
Six week old male Sprague-Dawley rats were administered intravenous clozapine, quetiapine, haloperidol or vehicle once daily for a period of 42 days with access to only high fat diet and their weight was monitored regularly. At the end of the study the rats were killed and the tibiae excised and bone mineral density (BMD) measured with dual X-ray absorptiometry and bone architecture assessed with micro-computed tomography (micro-CT) and associated software. Results were subjected to one-way ANOVA and post hoc Dunnetts multiple comparison test. All treatment groups were compared to control. There were no significant differences in body weight between the different groups at completion of the study. Clozapine treated animals alone showed a significant reduction in bone mineral density (p<0.05) however no differences were seen with haloperidol and quetiapine. Both haloperidol and quetiapine, but not clozapine, treatment showed a significant reduction in the bone to tissue volume ratio (BV/TV) by approximately 23% (p<0.05) and an increase in trabecular number (TbN) by approximately 21% (p<0.05). Trabecular bone architecture parameters for haloperidol and quetiapine, but not clozapine, showed more rod like and disconnected structure as reflected in the increases in structure model index (SMI) of around 15% (p<0.05) and trabecular pattern factor (TbPf) by 22% (p<0.05). This data demonstrates that in rats receiving a high fat diet, haloperidol and quetiapine have an adverse effect on bone micro-architecture without significant change in whole body bone mineral density. Clozapine did not affect bony architecture in a significant manner as reported in our earlier study, though bone mineral density was reduced. Reasons for the different effect of clozapine in this study are still uncertain but may be related to the significant weight loss seen at the end point of the previous study. Causes for osteoporosis and increased fracture risk in schizophrenia may include smoking history, malnutrition, limited sun exposure and compliance. Long term administration of both typical and atypical anti-psychotics may have a negative effect on bone and is a further factor that can influence this risk. An awareness of this relationship is useful in the orthopaedic management of schizophrenic patients.
Techniques for fixation of fractures of the lateral
malleolus have remained essentially unchanged since the 1960s, but
are associated with complication rates of up to 30%. The fibular
nail is an alternative method of fixation requiring a minimal incision
and tissue dissection, and has the potential to reduce the incidence
of complications. We reviewed the results of 105 patients with unstable fractures
of the ankle that were fixed between 2002 and 2010 using the Acumed
fibular nail. The mean age of the patients was 64.8 years (22 to
95), and 80 (76%) had significant systemic medical comorbidities.
Various different configurations of locking screw were assessed
over the study period as experience was gained with the device.
Nailing without the use of locking screws gave satisfactory stability
in only 66% of cases (4 of 6). Initial locking screw constructs
rendered between 91% (10 of 11) and 96% (23 of 24) of ankles stable.
Overall, seven patients had loss of fixation of the fracture and
there were five post-operative wound infections related to the distal
fibula. This lead to the development of the current technique with
a screw across the syndesmosis in addition to a distal locking screw.
In 21 patients treated with this technique there have been no significant
complications and only one superficial wound infection. Good fracture
reduction was achieved in all of these patients. The mean physical
component Short-Form 12, Olerud and Molander score, and American Academy
of Orthopaedic Surgeons Foot and Ankle outcome scores at a mean
of six years post-injury were 46 (28 to 61), 65 (35 to 100) and
83 (52 to 99), respectively. There have been no cases of fibular
nonunion. Nailing of the fibula using our current technique gives good
radiological and functional outcomes with minimal complications,
and should be considered in the management of patients with an unstable
ankle fracture.
The reinfusion of perioperative cell salvage is one method employed to reduce exposure to donor blood. Data on the safety of this process, however, are scant. Notably, the effect of intraoperative, washed cell salvage reinfusion on prothrombotic markers has not been demonstrated. The risk of postoperative venous thromboembolism following major orthopaedic operations is not insignificant. The study objective was to assess the effect of cell salvage reinfusion on coagulation and platelet activation. Twenty-one patients undergoing elective primary hip operations were recruited. Nine patients received washed cell salvage intraoperatively, and were compared with 12 patients undergoing similar surgery that did not. Two patients in the cell salvage group also received postoperative, unwashed cell salvage. Blood samples were collected pre-operatively, immediately post-operatively, and one day post-operatively for assays of platelet activation markers, P-selectin expression and fibrinogen binding by flow cytometry in diluted whole blood; coagulation activation marker, thrombin-antithrombin complex (TAT); D-dimer by ELISA, thrombin generation by chromogenic assay, and full blood count. Samples of cell salvage material were also analysed for prothrombotic markers. There were no significant differences between the groups preoperatively. Postoperatively haemoglobin levels did not differ significantly between the cell salvage group and controls. Postoperative TAT and D-dimer were significantly higher in the cell salvage group compared with controls (p<0.05). One day postoperatively, there were significantly higher platelet P-selectin expression (p=0.006) and platelet fibrinogen binding (p=0.004) in the cell salvage group compared with controls. The white cell count (WCC) was also significantly higher (p=0.04). In the intraoperative washed cell salvage material, and in postoperative cell salvage, the platelet count was low, but significant proportions of platelets were activated, and levels of D-dimer were elevated compared with venous blood. The postoperative salvage material also contained high levels of TAT. The results from this pilot study show the induction of a prothrombotic state following reinfusion of intraoperative, washed cell salvage in recipients undergoing primary elective hip operations. An inflammatory response to reinfusion is also indicated by the raised WCC. Further investigation into the safety of cell salvage is indicated.
TKA (Total Knee Arthroplasty) is a successful operation. Soft tissue problems with TKA are difficult to treat. Flap surgery is successful in treating this problem and salvaging the prostheses. We present results of flap surgery for complicated TKAs over a ten year period, performed by a single surgeon. Between 1996 and 2005, 31 patients (32 knees) underwent flap surgeries for TKAs. Four of these procedures were done prophylactically in patients with previous knee surgeries. Gastrocnemius, medial fasciocutaneous and anterior compartment flaps were used either solely or in combination based on the size of the defect. The data was collected retrospectively from case-notes and correspondence from the treating orthopaedic surgeons. All the knees included in the study had a minimum follow up of 6 months. The patients were aged between 50 and 94 years. Indication for primary TKA was osteoarthritis in 26 patients and rheumatoid arthritis in 5. The index orthopaedic surgery was a primary knee arthroplasty in 14 and revision in 13. The average duration between the TKA and flap surgery was 11 weeks (range 1 – 52). Gastrocnemius was the most commonly used local flap (17 cases). Anterior compartment flap was used in 5 cases and in the rest combination of flaps was used. Coagulase -ve Staph. aureus was the most commonly isolated organism from the perioperative wound swabs. Successful soft tissue cover was achieved in 29 of 32 knees (92%). Overall, TKA was salvaged in 23 of 32 knees (72%) and 3 knees (9.7%) underwent arthrodesis. Three (9.7%) patients had above knee amputation, two of these had post op MRSA infection. We could not use a functional knee scoring system due to inadequate information available. We conclude local flap surgery is a viable and successful procedure for providing soft tissue cover for complicated TKAs with good results.
Shoulder pain represents a significant burden of disease in the general population, yet there is a lack of evidence about the effectiveness of routinely used interventions. Current management of ‘painful arc’ of the shoulder in Primary Care is not evidence-based. Over a six-month period patients with ‘painful arc’ of less than six months duration were recruited via their GPs. Eligible patients were consented to enter the trial and were then randomised, by sealed envelopes, to one of four arms of the study: control (normal analgesia and/or non-steroidal anti-inflammatory medication), a specified and repeatable Exercise and Manual Therapy Package (EMTP), a course of up to three subacromial steroid injections or both the EMTP and the steroid injections. The interventions and clinic follow-ups were over an 18-week period. A final postal questionnaire was sent out at one year. The progress of the patients was monitored using the Oxford Shoulder Score (OSS) and the SF36 general health questionnaire. Seventy-nine GPs referred 186 patients, of whom 112 were randomised (Control=27, EMTP=29, Injections=28, Both=28). 64 patients were female and 48 male. The mean age was 54.5 years (range 23-88 years). Ninety patients completed the trial (Control=20, EMTP=22, Injections=26, Both=22). Sixty-two returned the follow-up questionnaire. By paired sample t-tests, no significant differences were found between the OSS scores or SF-36 (physical health total) at the beginning and end of the intervention period, or at one year, in any group. There were no differences in changes in scores between groups. Two patients in the injection group went on to surgery, along with one each in the control and EMTP groups. We have found no significant differences in outcome between steroid injections, a physiotherapy package, both treatments, or symptomatic treatment in our group of patients presenting with symptoms of painful arc of the shoulder.
Patients with spinal cord injuries have been seen to have increased healing of attendant fractures. This for the main has been a clinical observation with laboratory work confined to rats. While the benefits in relation to quicker fracture healing are obvious, this excessive bone growth (heterotopic ossification) also causes unwanted side effects, such as decreased movement around joints, joint fusion and renal tract calculi. However, the cause for this phenomenon remains unclear. This paper evaluates two groups with spinal column fractures – those with neurological compromise (n=10) and those without (n=15), and compares them with a control group with isolated long bone fractures (n=12). Serum was taken from these patients at five specific time intervals post injury (1 day, 5 days, 10 days, 42 days (6 weeks) and 84 days (12 weeks)). These samples were then analysed for levels of Transforming Growth Factor-Beta (TGF-β using the ELISA technique. This cytokine has been shown to stimulate bone formation after both topical and systemic administration. Results show TGF-β levels of 142.79+/-29.51 ng/ml in the neurology group at 84 days post injury. This is higher than any of the other time points within this group (p=0.009 vs. all other time points, ANOVA). Furthermore, this level is also higher than the levels recorded in the no neurology (103.51+/-36.81 ng/ml) and long bone (102.28=/-47.58 ng/ml) groups at 84 days post-injury (p=0.009 and p=0.04 respectively, ANOVA). In conclusion, the results of this work, carried out for the first time in humans, offers strong evidence of the causative role of TGF-β in the increased bone turnover and attendant complications seen in patients with acute spinal cord injuries.
Previous work( EMG data was recorded from 192 subjects across two years (initial contact, 12 months and 24 months). The data were analysed and SCMs produced. The 30 second test data was split into 30 one second epochs. Colour values were scaled to the individual data set maximum and divided into 12 bands according to frequency strength at a particular point. Median Frequency values were calculated for each epoch and a line of best fit added to the colour map to further aid the diagnosis process. Maps with faulty recordings were excluded and 20 data sets from each group (BP and no BP) selected at random. Four observers were given only 5 minutes instruction and then asked to indicate whether they thought each map belonged to the LBP or no LBP group.Introduction
Methods
existing reviews; an international think tank charged with producing updated reviews and identifying research gaps. An extended conceptual development of a ‘flags framework’, based on the earlier approach of Yellow Flags, was used to prepare an easily understood and pragmatic approach. The framework integrates obstacles related to the person (yellow flags), the workplace (blue flags) and the context (black flags). A full-colour 32-page document suitable for distribution as both print and electronic media was developed. This contains a clear explanation of how to identify psychosocial flags, how to develop a plan to address them effectively, and how to take action to overcome the obstacles. Poster-style summaries for clinicians, the workplace, and the individual are included, and are available for download. International consultation was used to ensure system-independent applicability and language.
The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation. Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry. We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.
The purpose of this prospective study was to determine the predictive factors and hence optimal management of closed uncomplicated proximal radial fractures. We examined all patients presenting to our unit over an 18-month period with isolated closed proximal radial fractures. 237 consecutive patients were included. Demographic data, physical examination, radiographs, treatment and complications were recorded. Patients were reviewed at 2, 6, 12, 26 and 52 weeks post injury. Outcome was determined via functional assessment and Mayo Elbow Score (MES). Data were analysed using SPSS. There were 156 (66%) radial head fractures and 81 (34%) radial neck fractures. 225 (95%) patients were treated non-operatively in a collar and cuff for one week followed by physiotherapy. 12 (5%) patients required primary surgical intervention due to either a mechanical block to forearm rotation (n=4) or a significant degree of radiographic comminution and/or displacement (n=8). Of the 201 patients who attended follow-up, 183 (91%) patients achieved excellent or good functional results measured on the MES. 155 (78%) patients achieved this by six weeks, with an average flexion arc of 125 degrees. Of the 12 patients treated operatively, the average MES at six weeks was fair (60). Regression analysis showed that increasing age, the AO-OTA fracture classification (B2.3, C2.3), radiographic displacement and operative treatment were significant predictors of a fair or poor outcome at six weeks. The majority of isolated proximal radial fractures can be treated non-operatively with early mobilization, achieving excellent or good results within 6 weeks. Age, fracture classification, radiographic displacement and treatment choice are important factors that determine speed of recovery.
Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) permits inference of glycosaminoglycan (GAG) distribution. We aimed to determine whether hips with cam deformities have altered GAG content, using dGEMRIC.
2 regions of interest (ROI) were studied:
acetabular cartilage from 12 to 3 O’Clock (T1-Index-acet). total cartilage (femoral and acetabular) for the joint from 9 to 3 O’Clock (T1-Indextotal). The average of all pixels within the given ROI defined the T1-index. For each hip, the ratio of the GAG content T1-Index-acet/T1-Indextotal was calculated. Mean T1-Indexto-tal and T1-Indexacet/T1-Indextotal were compared.
We carried out a retrospective review of 47 intra-articular fractures of the calcaneum treated by open reduction and internal fixation in 45 patients by a single surgeon between 1993 and 2001. The fractures were evaluated before operation by plain radiographs and a CT scan using Sanders’ classification. Osteosynthesis involved a lateral approach and the use of the AO calcaneal plate. The mean follow-up was for ten years (7 to 15). Clinical assessment included the American Orthopaedic Foot and Ankle Society Score (AOFAS), the Creighton-Nebraska Score, the Kerr, Prothero, Atkins Score and the SF-36 Health Questionnaire. The radiological evaluation consisted of lateral and axial views of the os calcis. Arthritic changes in the subtalar joint were assessed with an internal oblique view and were graded using the Morrey and Wiedeman scale. There were 18 excellent (38.3%), 17 good (36.2%), three fair (6.3%) and nine poor (19.2%) results. Five patients had a superficial wound infection and five others eventually had a subtalar arthrodesis because of continuing pain. Restoration of Böhler’s angle was associated with a better outcome. The degree of arthritic change in the subtalar joint did not correlate with the outcome scores or Sanders’ classification. Prompt osteosynthesis should be considered for intra-articular fractures of the calcaneum in order to restore the shape of the hindfoot and Böhler’s angle.
Patients with spinal cord injuries have been seen to have increased healing of attendant fractures. While the benefits are obvious, this excessive bone growth also causes unwanted side effects, such as decreased movement around joints, joint fusion and renal tract calculi. However, the cause for this phenomenon remains unclear. This paper evaluates two groups with spinal column fractures – those with neurological compromise (n=10) and those without (n=15), and compares them with a control group with isolated long bone fractures (n=12). Serum was taken from these patients at five specific time intervals post injury (1 day, 5 days, 10 days, 42 days (6 weeks) and 84 days(12 weeks)). These samples were then analysed for levels of Transforming Growth Factor-Beta (TGF-.) using the ELISA technique. This cytokine has been shown to stimulate bone formation after both topical and systemic administration. Results show TGF-.; levels of 142.79±29.51 ng/ml in the neurology group at 84 days post injury. This is higher than any of the other time points within this group (.0.009 vs. all other time points, ANOVA). Furthermore, this level is also higher than the levels recorded in the no neurology (103.51±36.81 ng/ml) and long bone (102.28±47.58 ng/ml) groups at 84 days post injury (p=0.009 and p=0.04 respectively, ANOVA). In conclusion, the results of this work, carried out for the first time in humans, offers strong evidence of the causative role of TGF-.; in the increased bone turnover and attendant complications seen in patients with acute spinal cord injuries.
Despite tendencies for Claims against medical practitioners around Australia to fall, litigation continues to be a burden on individual practitioners and the system. Unlike Claims frequency, Claims costs are not falling and indemnity insurance remains a significant practice cost. Data is presented to illustrate some trends in litigation and illustrative cases are also presented to outline some of the difficulties in defending Claims. Particular emphasis on the degree of difficulty is made in respect of Epidural Abscess.
Leptin is a major hormonal product of the adipocyte which regulates appetite and reproductive function through its hypothalamic receptors. It has now become clear that leptin receptors are much more widely distributed than just the hypothalamus, and the skeleton has emerged as an important site of action of leptin. The signalling form of the leptin receptor has been found in several cell types including human osteoblasts, rat osteoblasts and human chondrocytes. In vitro we have shown leptin to an anabolic factor, stimulating osteoblast proliferation and inhibiting osteoclastogenesis. Leptin increases bone mass and reduces bone fragility when administered peripherally but has an indirect inhibitory effect on bone mass via the hypothalamus when administered directly into the central nervous system. Data from animal models where there is an absence of either leptin production (ob/ob) or its receptor (db/db) have been contradictory. In this study we compared the bone phenotype of leptin receptor-deficient (db/db) and wild-type (WT) mice. Micro-CT analysis was done on proximal tibiae using a Skyscan 1172 scanner. Db/db mice had significantly reduced trabecular bone volume, trabecular thickness and trabecular number and a higher degree of trabecular separation. Cortical bone was also significantly lower in db/db animals in volume, cross-sectional thickness and perimeter. These results demonstrate that in the absence of leptin signalling there is reduced bone mass indicating that leptin indeed acts in vivo as a bone anabolic factor, mimicking the in vitro results.
Adiponectin, a hormone secreted by adipocytes, regulates energy homeostasis and glucose and lipid metabolism. Plasma levels of adiponectin are negatively correlated with body fat mass. Adiponectin inhibits the formation and activity of osteoclasts and increases the proliferation and differentiation of osteoblasts in vitro. The aim of our study was to determine the bone phenotype of adiponectin knockout mice. Male adiponectin-deficient (Ad-KO) and wild-type (WT) C57BL/6J mice were sacrificed at 8, 14 and 22 weeks of age. Body weights did not differ between Ad-KO and WT mice. We scanned the left proximal tibia using micro-CT at 5μm resolution and analysed bone microarchitecture by 3D analysis. We found significant increases in trabecular bone volume (BV/TV) (15.9±1.63 vs. 12.2±0.72%, p=0.02) and trabecular number (3.20±0.18mm-1 vs. 2.32±0.12mm-1, p=0.0009) in 14-week old Ad-KO mice compared to controls. Similar differences between WT and Ad-KO were present in 8 and 22-week old animals but these did not reach statistical significance. Trabecular thickness was significantly greater (0.053±0.001mm vs. 0.048±0.002mm, p=0.04) in 22-week old Ad-KO mice compared to WT. Ad-KO mice have increased number and volume of trabeculae at 14 weeks of age indicating that the net effect of adiponectin on bone accrual in vivo is inhibitory. These effects are age-dependent. Our data concur with the observations from epidemiological studies in humans that adiponectin negatively correlates with both fat mass and bone mass. Therefore, adiponectin may be a contributor to the link between fat and bone mass.
The current standard of care in Calgary, Alberta for management of a ruptured Achilles tendon is surgical repair, typically performed following admission to hospital. The primary objective of this study was to compare the costs of hospital treatment and complications associated with the surgical repair of Achilles tendon ruptures between two groups of patients: Group One = patients enrolled in the randomised clinical trial (RCT) Multicentre Achilles Tendon Treatment Study (MATTS), Group Two = all other non-study patients. This observational cohort study analyzed all patients surgically treated for Achilles tendon ruptures at Calgary area hospitals over a three-year period (October 2002–September 2005). Inclusion criteria: age eighteen to seventy years, acute rupture. A total of two hundred and eighty-two patients met the inclusion criteria; thirty-three patients were included in Group One, two hundred and forty-nine patients in Group Two. In Group One, twenty-seven patients (82%) were treated as outpatients, five patients (15%) were ADOP-24hr, and one patient (3%) was admitted. In Group Two, twenty-seven patients (11%) were treated as outpatients, ninety-five patients (38%) were ADOP-24hr, and one hundred and twenty-seven patients (51%) were admitted. The total costs for patients treated as outpatients and requiring overnight stays in Group One were $18,408 and $7,419, respectively. In Group Two, the total cost for outpatients was $18,071 compared to $379,496 for non-study patients requiring overnight stay. If all overnight patients in each group were treated as outpatients, the total savings would be $235,545. There were no serious complications in Group One. In Group Two, complications included two cases of pulmonary embolus, and one case of compartment syndrome requiring readmission. All complications resolved. Surgical treatment of Achilles tendon rupture can be performed safely and at less cost on an outpatient basis. Participation in this RCT has allowed us to recommend a change in the standard of care in Calgary.
Intramedullary Nailing is now accepted as the standard treatment for most femoral diaphyseal fractures. Most intramedullary nails are designed for proximal and distal locking with screws. We describe our experience with the Brooker Wills femoral nail. This nail is unique as distal fixation is achieved with as transverse fixator deployed through slots in the nail, a concept first enunciated by deCamargo in 1952. The fins of the fixator pierce the distal cortex when deployed thereby conferring rotational stability. The entire nail (including the proximal and distal fixation devices) can be inserted through a single proximal incision in the skin. We treated 17 patients with femoral shaft fractures using this system. 93% of the patients were males. Motor vehicle accidents accounted for 80 % of the fractures. Most fractures involved the middle third of the femur (54%), followed by distal third (33%) and proximal third (13%). 67 % of the fractures showed Winquist and Hansen Grade 3 or 4 comminution. All the nailings were performed in the supine position. Static locking was done in 16 cases. Post operative weight bearing was individualized with 86% of the patients bearing full weight before the end of 16 weeks. The average time to full weight bearing was 14 weeks. The mean time to union was 17.1 weeks, with proximal, middle and distal third fractures showing average healing times of 19, 15.6 and 18.8 weeks respectively. All the fractures united. There was one case of delayed union. Intra-operative complications included–inability to deploy the distal fixator in one case and unwinding of the reamer in another case. There was one case of superficial infection where a patient developed a sinus over the metallic fin of the distal fixation device, which had penetrated the cortex. This healed after the distal fixation device was removed. There was one case of proximal nail migration, but the fracture went onto union with some limb shortening. Results were evaluated using the scoring system devised by Sanders etal (1991). The functional criteria in their scoring system include- knee flexion, presence of pain, femur deformity, walking distance, stair climbing and pre injury functional status. We achieved excellent results in 53% of patients, good- 27%, fair–13 % and poor-7%. We feel that the main advantage of the Brooker Wills Nail is the ease of distal locking. This saves time and also leads to lower level of radiation exposure, as the image intensifier is sparingly used for distal locking. In fact, this nail is an attractive option in centres which lack an image intensifier. We achieved good results with this nailing system and feel that it is an acceptable alternative to other nailing systems with conventional locking systems with screws.
The aim of this randomised, controlled trial is to compare subacromial steroid injections, physiotherapy and both interventions with a control treatment in early painful arc of the shoulder. Over a six-month period patients with “painful arc”, of less than six months duration, were recruited via their GPs. Eligible patients were consented to enter the trial and were then randomised, by sealed envelopes, to one of four arms of the study: control (normal analgesia and/or non-steroidal anti-inflammatory medication), a specified and repeatable Exercise and Manual Therapy Package (EMTP), a course of up to three subacromial steroid injections or both the EMTP and the steroid injections. The interventions and clinic follow-ups were over an 18-week period. A final postal questionnaire was sent out at one year. The progress of the patients was monitored using the Oxford Shoulder Score (OSS) and the SF36 general health questionnaire. Seventy-nine GPs referred 186 patients, of whom 112 were randomised (Control=27, EMTP=29, Injections=28, Both=28). 64 patients were female and 48 male. The mean age was 54.5 years (range 23–88 years). Ninety patients completed the trial (Control=20, EMTP=22, Injections=26, Both=22). Sixty-two returned the follow-up questionnaire. By paired sample t-tests, no significant differences were found between the OSS scores or SF-36 (physical health total) at the beginning and end of the intervention period, or at one year. Two patients in the injection group went on to surgery, along with one each in the control and EMTP groups. We have found no significant differences in outcome between steroid injections, a physiotherapy package, both treatments, or symptomatic treatment in our group of patients presenting with symptoms of painful arc of the shoulder.
Eligible patients randomised to one of four arms of the study: control (normal analgesia and/or non-steroidal anti-inflammatory medication), a specified and repeatable Exercise and Manual Therapy Package (EMTP), a course of up to three subacromial steroid injections or both the EMTP and the steroid injections. Follow-up was for 18 weeks, with postal questionnaire at one year. The primary outcome measure was the Oxford Shoulder Score (OSS).
By analysis of covariance, no significant differences were found between the OSS scores or SF-36 (physical health total) at the beginning and end of the trial, or at one year. Two patients in the injection group went on to surgery, along with one each in the control and EMTP groups. No significant differences were found between treatment groups.