Risk factors for osteoarthritis include raised BMI and female gender. Whether these two factors influenced synovial gene expression was investigated using a triangulation and modelling strategy which generated 12 datasets of gene expression in synovial tissue from three knee pathologies with matching BMI groups, obese and overweight, and gender distributions. Intra-operative synovial biopsies were immersed in RNAlater at 4oC before storage at -80oC. Total RNA was extracted using RNAeasy with gDNA removal. Following RT- PCR and quality assessment, cDNA was applied to Affymetrix Clariom D microarray gene chips. Bioinformatics analyses were performed. Linear models were prepared in limma with gender and BMI factors incorporated sequentially for each pathology comparison, generating 12 models of probes differentially expressed at FDR p<0.05 and Bayes number, B>0. Data analysis of differently expressed genes utilized Ingenuity Pathway Analysis and Cytoscape with Cluego and Cytohubba plug-ins.Abstract
Introduction
Methodology
It is increasingly evident that synovium may play a larger role in the aetiology of osteoarthritis. We compared gene expression in whole tissue synovial biopsies from end-stage knee osteoarthritis and knee trauma patients with that of their paired explant cultures to determine how accurately cultured cells represent holistic synovial function. Synovial tissue biopsies were taken from 16 arthroplasty patients and 8 tibial plateau fracture patients with no osteoarthritis. Pairs of whole tissue fragments were either immediately immersed in RNAlater Stabilisation Solution at 4o C before transfer to -80o C storage until RNA extraction; or weighed, minced and cultured at 500mg tissues/5ml media in a humidified incubator at 37oC, 5% CO2. After sub-culturing total RNA was extracted using RNAeasy Plus Mini Kit with gDNA removal. Following RT-PCR and quality assessment, cDNA was applied to Affymetrix Clariom D microarray gene chips. Bioinformatics analyses were performed.Abstract
Introduction
Methodology
Articular cartilage degradation is a defining feature of osteoarthritis. Synovium is a reactive tissue with synovial villae, neoangiogenesis and intimal hyperplasia common to many joint pathologies. The consequences of cartilage debris in osteoarthritis impacting the synovial intima is not well understood. We analysed the immunohistology of synovium from 16 patients with osteoarthritis and 17 patients undergoing knee surgery for non-arthritic pathologies. This data was integrated with imaging and functional scores to correlate synovitis in osteoarthritis. Formalin-fixed paraffin embedded synovial biopsy sections were cut in serial sequence and processed for routine staining (H&E or CD3, CD68, CD20, Vimentin, vWF and PCNA IHC) using standardised Dako monoclonal mouse anti-human antibodies. Digital images scanned at x20 were evaluated for fragments of cartilage and aggregates of inflammatory cells. Clinical data (gender, BMI, KL grade, WOMAC & SF-12 scores) was aligned with histopathological data.Abstract
Introduction
Methodology
Synovitis impacts osteoarthritis symptomatology and progression. The transcription factors controlling synovial gene expression have not been described. This study analyses gene expression in synovium samples from 16 patients with osteoarthritis with 9 undergoing arthroscopic and 8 knee trauma surgery for non-arthritic pathologies. Intra-operative synovial biopsies were immersed in RNAlater at 4oC before storage at -80oC. Total RNA was extracted using RNAeasy. After purification, RT-PCR and quality assessment, cDNA was applied to Affymetrix Clariom D microarray gene chips. Bioinformatics analyses were performed. Linear models were prepared in limma with gender and BMI factors incorporated sequentially for each pathology comparison, generating 12 models of probes differentially expressed at FDR p<0.05 and Bayes number, B>0. Data analysis of differently expressed genes utilized Ingenuity Pathway Analysis and Cytoscape with Cluego and Cytohubba plug-ins.Abstract
Introduction
Methodology
Bio-impedance analysis (BIA) provides a convenient method for the estimation of whole body and segmental measurement of skeletal muscle mass (SMM). BIA-measured SMM parameters may be effectively used for the normalisation of muscle strength and removing body-size dependence. Despite an increasing interest in using bio-impedance analysis (BIA) for the estimation of segmental skeletal muscle mass (SMM); existing data is sparse. On the other hand, there is a need for better understanding of the influence of SMM on gender-related differences in muscle strength. Using BIA technique, this study aimed to measure the SMM, determine its correlation with muscle strength, and examine its relation with gender-related differences in muscle strength.Summary Statement
Introduction
Applying appropriate upper limb regional-specific and joint-specific tools along with suitable psychologic tools provides an effective assessment of supportive, interventional, and treatment strategies in TE. Tennis elbow (TE) is a painful pathologic condition with its origin in the common wrist extensor muscles at the lateral epicondyle. As the second most frequently diagnosed musculoskeletal disorder in the neck and upper limb in a primary care setting, with an annual incidence of 4 to 7 cases per 1000 patients in general practice (with a peak at 35 to 54 yrs of age), TE has considerable socioeconomic costs. As pain relief and improvement in functional performance are the 2 common aims of all treatment strategies, the importance of using appropriate tools for the assessment of pain and functional disability in TE is evident. In view of the high prevalence of TE, uncertainties about its treatment, and its substantial socioeconomic consequences, using more specific, patient-centred assessment tools is essential for providing more useful information on the level of pain and functional disability in TE. The Study aimed to: 1) compare pain and functional disability in tennis elbow (TE) patients with healthy controls; and 2) evaluate the relationship between the 2 major psychologic factors (anxiety and depression) and TE.Summary Statement
Background
Discovery system produced effective functional improvement in both primary and revision total elbow replacement. The incidence of major complications was in an acceptable range. The search for the ideal elbow prosthesis continues as instability and loosening remain the prime reasons for total elbow replacement (TER) failure. The Discovery Elbow System (Biomet) is one of the latest generations of linked prosthesis and has been used in UK since 2003. We report outcome of TER using this system.Summary Statement
Introduction
Evaluation of the early results of the implementation of reverse shoulder arthroplasty prosthesis “Comprehensive Reverse” in primary and revision shoulder arthroplasties. September 2010–December 2012, 48 patients (32 women, 16 men) underwent reverse shoulder arthroplasty using Comprehensive Reverse system. Average age of 69.88. A total of 46 patients were followed. In 22 patients the operation was performed for revision. Patients were pre-and postoperatively evaluated using Oxford, Constant, SF-12 scores, radiographs, pain and range of motion. Mean follow-up 13 months.Objective:
Material and Methods:
Wear debris from articulating joint implants is inevitable. Small debris particles are phagocytosed by macrophages. Larger particles initiate the fusion of many macrophages into multi-nucleated giant cells for particle encasement. Macrophages are recruited into inflamed tissues from the circulating monocyte population. Approximately 10% of white blood cells are monocytes which after release from the bone marrow circulate for 2–3 days, before being recruited into tissues as inflammatory macrophages or undergoing apoptosis. Circulating MRP8/14 (S100A8/A9) is a measure of monocyte recruitment, part of the monocyte-endothelial docking complex, and shed during monocyte transmigration across the endothelium. The higher the S100A8/A9 the more monocytes being recruited giving an indirect measure of debris production. 2114 blood samples were collected from arthroplasty patients with hip or knee osteoarthritis (primary, post-traumatic and secondary), 589 before their primary arthroplasty, 1187 patients > 1 year post-arthroplasty, 101 patients before revision for aseptic loosening and 237 patients >1 year post-revision. Plasma S100A8/A9 was measured using BMA Biomedicals Elisa kit, normal levels in health adults are 0.5–3 mg/ml. Joint specific scores, WOMAC knee or Oxford Hip adjusted to percent of maximum, together with SF-12 were completed.Introduction:
Methods:
The risk factors for degenerative joint disease are well established: increasing age, obesity, joint abnormalities, trauma and overuse, together with female gender, ethnic and genetic factors. That obesity is a significant risk factor for developing osteoarthritis in non-weight-bearing as well as weight-bearing and joints was one of the first indications that the risk was nor purely that of aberrant biomechanical loading. Low grade chronic systemic inflammation is a component of each of ageing and obesity, atherosclerosis and diabetes, culminating in Metabolic Syndrome. In our study of 1684 patients with joint degeneration 85% were overweight or obese and 65% older than 65 years with 62% being both, 73% of patients were taking medications for serious, ‘non-orthopaedic’ health problems such as cardiovascular or respiratory disease, obesity or NIDDM. Monocytes are a major component of chronic inflammation, approximately 10% of white blood cells are monocytes which circulate for 2–3 days, before being recruited into tissues as inflammatory macrophages or undergoing apoptosis. Circulating S100A8/A9 (MRP8/14) is a measure of monocyte recruitment being shed during monocyte transmigration across the endothelium. The higher the S100A8/A9 the more monocytes being recruited giving an indirect measure of chronic inflammatory status. 2154 blood samples were collected from arthroplasty patients (first or second joint replacement), 1135 Female and 1019 Male, age 29–93 years, body mass index (BMI) 18–56, with hip or knee osteoarthritis (primary, post-traumatic and secondary), 589 before a primary arthroplasty, 1187 patients >1 year post-arthroplasty, 101 patients before revision for aseptic loosening and 237 patients >1 year post-revision. All study patients received metal on UHMWPE implants. Plasma S100A8/A9 was measured using BMA Biomedicals Elisa kit, normal levels in healthy adults are 0.5–3 mg/ml. The data were analysed using SPSS, p values were calculated using Spearman's test.Introduction:
Methods:
Rehabilitation after shoulder arthroplasty is a fundamental in enabling patients achieve a good functional outcome. Therapists must consider the underlying diagnosis, operative technique employed and rotator cuff integrity, amongst other factors, in order to select the most appropriate exercise regime. There is an absence of comprehensive studies in the literature with regard to shoulder rotational exercises. Therefore, this study aimed to describe the shoulder girdle muscle activation strategies during eight commonly cited rotational shoulder exercises. Thirty healthy subjects with no history of shoulder problems participated in the study. EMG was recorded from 16 shoulder girdle muscles (surface electrodes: anterior, middle and posterior deltoid, upper, middle and lower trapezius, upper and lower latissimus dorsi, upper and lower pectoralis major; fine wire electrodes: supraspinatus, infraspinatus, subscapularis and rhomboid major) using a telemetry based EMG system. Five external and three internal rotation exercises were included (table 1). Signal acquisition and processing were in accordance with standardised guidelines. Amplitude normalisation was to external and internal rotation maximum voluntary contraction as appropriate. Mean EMG amplitudes between exercises were compared using repeated measures ANOVA. Data for muscle groups was calculated by averaging the activation of the component muscles.Introduction
Method
The procedures of total elbow and shoulder replacements increased 6% to 13% annually from 1993 to 2007 with revision-related burden increasing from 4.5% to 7%. The revisions of the shoulder and elbow prostheses due to aseptic loosening, periprosthetic fractures, infections have led to the use of standard or custom-made implants due to significant bone loss. This study reports our experience in the management of complicated primary and revisions of total shoulder and elbow replacements with significant humeral bone loss and in metabolic diseases of the elbow and shoulder treated with bone resection using The Mosaic Humeral Replacement System. A total of 20 patients underwent total elbow or shoulder arthroplasty using the Mosaic Humeral Replacement System (Biomet, UK). The Mosaic system was used in 8 shoulder arthroplasties (Group A) and in 12 elbow arthroplasties (Group B). The underlying pathologis in Group A included 2 malunited proximal humerus fracture, 1 humeral osteomyelitis, 1 shoulder chondrosarcoma, 1 aggressive Gigantic Cell Tumor with prosthetic fracture, 2 metastatic lytic lesion, and 1 failed fixation of non-union proximal humerus. Figure 1 shows Mosaic implant after complex fracture of proximal humerus. Reasons for Mosaic arthroplasty in Group B included 3 humeral component revisions due to periprosthetic fracture, 1 prosthesis breaking-up with fractures, 1 revision of loose Souter Strathclyde prosthesis, 1 loose prosthesis due to infection, 1 highly comminuted elbow fracture, 1 aseptic loosening of humeral component of total elbow replacement, 3 revision of total elbow replacement due loosening and 1 pathological distal humerus fracture due to metastasis. Figure 2&3 shows pre- and post-operative Mosaic implant following complex periprosthetic fracture of distal humerus.Background
Patients and Materials
The quest for the perfectly designed elbow prosthesis continues as instability and loosening remain the foremost reasons for the failure of total elbow replacement (TER). The Discovery® Elbow System (Biomet, UK) (Figure 1), which has been used in UK since 2003, is one of the latest generations of linked prosthesis. This system was designed to decrease polyethylene-bushing wear, improve anatomic stem design, restore elbow joint biomechanics, and produce a hinge that could be easily revised. This report describes the short term outcome of TER using the Discovery® Elbow System. A total of 60 TERs including 48 primary and 12 revisions were performed between 2003 and 2008. Patients included 21 males (37%) and 36 females (63%) with a mean age of 63 years. The indications for primary TER were advanced rheumatoid arthritis (n=19), osteoarthritis (n=16), post traumatic osteoarthritis (n=9), acute fractures (n=3), and haemophilic arthropathy (n=1). The outcome was assessed using pain score, Liverpool Elbow Score (LES), and range of movement during a mean follow-up of 26 months. Associated complications were documented. Radiological assessment included evaluation for loosening, instability and periprosthetic fractures.Background
Patients and Methods
The Copeland shoulder resurfacing arthroplasty (CSRA) (Figure1) is a cementless, pegged humeral head surface replacement which has been in clinical use since 1986. The indications for CSRA are more or less the same as conventional stemmed arthroplasty. This procedure can be considered for all patients who require shoulder replacement due to GHJ arthritis resulted from primary or secondary OA, RA, and other variations of inflammatory arthritis. It is also suggested as the first choice option for relatively young patients with post-traumatic arthritis, avascular necrosis (AVN), and instability arthropathy. This observational study reports functional and radiological outcome in CSRA during 4 years follow-up. 109 consecutive patients with primary osteoarthritis (45.9%), rheumatoid arthritis (39.4%), rotator cuff arthropathy (9.2%), and avascular necrosis (5.5%) underwent CSRA. Patients including 68 females (63%) and 41 males (37%) underwent this procedure (63 right-sided and 46 left-sided including 9 bilateral shoulders). The outcome assessment included pain and satisfaction, Oxford Shoulder Score (OSS), Constant Score (CS), and SF-12. Imaging was reviewed for glenoid morphology (Walch classification) (Figure2) and humeral head migration. The average follow-up period was 4 years, (range: 1 to 10 years).Background
Methods
Reverse total shoulder arthroplasty (RTSA) provides an alternative to standard total shoulder arthroplasty in the treatment of selected complex shoulder problems including failed shoulder replacements. The purpose of this report is to present outcome of RTSA using Comprehensive Reverse System (CRS) as either primary or revision treatment choice. Between September 2010 and April 2012, 54 patients (36 females, 18 males) with the mean age of 68.4 (±10) underwent RTSA-CRS. In 27 patients RTSA-CRS was performed as a revision due to failed previous arthroplasty. Primary underlying conditions included AVN (2), massive irreparable rotator cuff tear (2), primary osteoarthritis (7), post-traumatic osteoarthritis (2), rheumatoid arthritis (6), and rotator cuff arthropathy (8). It was not possible to complete the operation in 6 patients (4 revisions group 2 AVN cases) due to substantial glenoid erosion. Preoperative CT scan was performed in 50% of patients to assess the bony stock of the glenoid. In some patients ultrasound and MRI were performed to acquire additional information. A total of 46 patients were followed-up by means of antroposterior and axial plain X-rays, pain and satisfaction level (VAS/0–10), stiffness, Constant Score, Oxford Shoulder Score, SF-12 (Physical and mental Subscales), and range of movement for a mean duration of 6.5 months (±4.2).BACKGROUND
PATIENTS AND MATERIALS
Shoulder motion results from a complex interaction between the interconnected segments of the shoulder girdle. Coordination is necessary for normal shoulder function and is achieved by synchronous and coordinated muscle activity. During rotational movements, the humeral head translates on the glenoid fossa in the anterior-posterior plane. Tension developed by the rotator cuff muscles compresses the humeral head into the glenoid fossa. This acts to limit the degree of humeral head translation and establishes a stable GH fulcrum about which the arm can be moved. Previous studies have been limited by the use of contrived movement protocols and muscular coordination has not been previously considered with regard to shoulder rotation movements. This study reports the activation profile and coordination of 13 muscles and 4 muscle groups during a dynamic rotational movement task based on activities of daily living. Eleven healthy male volunteers were included in the study. Electromyography (EMG) was recorded from 13 muscles (10 surface and 3 fine-wire intramuscular electrodes) using a wireless EMG system. EMG was recorded during a movement task in which the shoulder was consecutively rotated internally (phase 1) and externally (phase 2) with a weight in the hand. Muscle group data was calculated by ensemble averaging the activity of the individual component muscles. Mean signal amplitude and Pearson correlation coefficient (PCC) analysed muscle activation and coordination, respectively.Introduction
Methods
The aim of this study was to evaluate prospectively the outcome following arthroscopic Bankart repair using two types of suture anchors, absorbable and non-absorbable. Patients with a diagnosis of recurrent traumatic anterior instability of the shoulder, seen between April 2000 and June 2003 in a single unit, were considered for inclusion in the study. Patients were assessed pre-operatively and post-operatively using a subjective patient related outcome measurement tool (Oxford instability score), a visual analogue scale for pain and instability (VAS Pain and VAS instability) and a quality of life questionnaire (SF-12). The incidence of recurrent instability and the level of sporting ability were recorded. Patients were randomised to undergo surgical repair with either non-absorbable or absorbable anchors. 130 patients were included in the study. 6 patients were lost to follow-up and 124 patients (95%) completed the study. Both types of anchors were highly effective. There were no differences in the rate of recurrence or any of the scores between the two. Four patients in the non-absorbable group and 3 in the absorbable group experienced further episodes of dislocation after a traumatic event. The rate of redislocation in the whole series was therefore, 5.6%. In addition, 4 patients, all of them in the absorbable group (4%) described ongoing symptoms of instability but no true dislocations. 85% of the patients have returned to their previous level of sporting activity. There are no differences in the outcome of Arthroscopic Bankart repair using either absorbable or non-absorbable anchors. Both are highly effective, showing a redislocation rate of 5.6%.
A prospective study was carried out over a period of 4 years. 31 patients with a mean age of 49 years were treated using the clavicular hook plate. The mean follow up was 28.34 months. 23 patients were operated primarily and 8 patients were operated for symptomatic non-union. All the patients achieved clinical and radiological union in a mean 12.71 weeks. According to Constant scoring the mean was 94. According to HSS (Hospital for Special Surgery) scoring 9 patients had excellent, 21 had good. The clinical results of the clavicular hook plate were good leading to good shoulder girdle function.
Scapular instability is a disabling deformity that results in pain and influences the overall upper limb function ; for which scapular stabilization may be necessary.
The technique used for fusion was plate and wires in 6, Rush pin and wires in 2. All of them had bone grafting . At the last follow up the mean DASH score was 37 and the mean constant score was 74.67. All patients had mild or no pain,felt their scapula stable and were satisfied with the outcome. The main post operative complaint was wire breakage and migration that necessitated removal in 3 patients. We conclude that scapulothoracic fusion is a valuable procedure and can restore reasonable shoulder function and relieve pain in patients with scapular instability.
Little is known about how arthroscopic knots behave in terms of reverse slippage and creep during the first few hours following a Bankart repair. We aimed to assess differences between knot types tied with a variety of suture materials when exposed to loading which might be expected during the first 12 hours following a repair. This study uses an apparatus to model the tensioning of a slipknot, the closing of a Bankart lesion and any reverse slippage occurring on removal of the tensioning force. Eight examples each of the Duncan loop and SMC knots were tied by an experienced surgeon using 4 different suture materials (PDS, Ethibond, Panacryl, Fibrewire). An arthroscopic knotting technique was used utilising a knot pusher. Each knot was locked with 3 half-hitches alternating direction and post each time. Any reverse slippage occurring during the tying process was recorded. Each knot was then left in situ for 12 hours under loads equivalent to a repaired Bankart lesion and any subsequent reverse slippage was recorded at the end of this period. After initial passing of the Duncan loop the sutures were ranked inversely to size of suture loop (resistance to slippage) in order Panacryl (5.08±0.15mm); Fibrewire (5.7±1.03mm); Ethibond (7.22±3.47mm) and PDS (8.2±5.16mm). After passing of locking hitches, they ranked Ethibond (5.13±0.24mm); PDS (5.15±0.09mm); Panacryl (5.17±0.13mm) and Fibrewire (5.66±0.5mm – significant p<
0.05). After 12 hrs, some evidence of reverse slippage was noted, Ethibond (5.23±0.27mm); PDS (5.27±0.13mm); Panacryl (5.3±0.16mm) and Fibrewire (5.66±0.5mm – significant p<
0.05). The SMC knot showed similar results. If a slip-knot back slips it can be tightened with the first locking hitch. After this further hitches do not tighten the knot further. Some slippage was noted during the first 12 hrs. Using arthroscopic techniques, Fibrewire performs less well than other materials.
Tennis elbow (lateral epicondylitis) is a common upper limb condition, possibly resulting from angiofibroblastic degeneration. Conservative treatment comprises corticosteroid injections, rest and splints, however, occasionally surgery is necessary. Recent data comparing Botulinum Toxin Type A (BTX-A) (Botox®, Allergan Inc, Irvine, CA) with surgery suggested BTX-A is effective in treating resistant tennis elbow by providing temporary, reversible paralysis of affected muscle, thereby alleviating tensile forces and allowing tissue healing. This double-blind, randomised, controlled trial compared BTX-A with placebo in 40 patients with chronic tennis elbow (>
6 months). Recruited patients were randomised to 50U BTX-A+2mL normal saline or 2mL normal saline (placebo). Injections were administered 5cm distal to the maximal area of lateral epicondyle tenderness. Quality of life (SF-12), pain (visual analogue scale) and grip strength (Jamar dynamometer) were assessed pre- and 3 months post-injection in both affected and non-affected arms. Following BTX-A treatment patients had average 19% improvement in grip strength in the affected arm compared to average 2% for placebo, however, this difference did not reach statistical significance (p=0.08, 95% CI −2.31, 35.64). No difference between the groups was seen for the unaffected arm (BTX-A 4% improvement, placebo 1% improvement). Both groups showed similar improvements in pain assessment and also in quality of life. BTX-A treated-patients demonstrated improved grip strength in the affected arm compared to placebo, however this difference was not statistically significant.
The purpose of this study was to analyse the effects of two different biomechanical configurations on the tensile properties of equine patellar tendons. The study looked at a comparison of straight untwisted patellar tendons and double stranded, twisted specimens. The aim was to attempt a more anatomical Anterior Cruciate Ligament configuration when performing reconstruction using the patellar tendon. Thirty four specimens were harvested and each sample group consisted of a pair of equine ligaments taken from the same animal. The first of the pair served as an ‘untwisted, straight ligament’ control group and the second as the ‘twisted, double stranded test group’. The ligament dimensions were measured for each specimen and the specimen was mounted on an Instron Series 4411© tensile testing machine and tensile load was applied until failure. Results showed a clearly statistically significant reduction in the tensile properties (p<
0.005) of the twisted double stranded specimens which was against our original hypothesis. The results indicated that the twisted double stranded ligaments had only 65% of the tensile strength of their untwisted counterparts. Similar reductions were demonstrated when calculating energy to yield point and load at zero point yield stress. The results also demonstrated a significant reduction in the stiffness (Young’s Modulus) between the two test configurations. The application of a double stranded twist to the patellar tendon confers no advantage in terms of tensile property of the ligament. In fact the application of such a model may cause significant reduction in strength and stiffness of the construct which may lead to early failure of the ACL patellar tendon autograft.
The use of crude mortality and morbidity data to assess the outcome from surgical intervention can be both dangerous and misleading. Furthermore, differences in outcome when comparing differing units or surgeons may be explained merely by variations in case mix and the type of surgery. In recent years there have been a number of attempts to devise a reliable method for assessing the outcome from surgical intervention. In the general surgical setting, the POSSUM system has proved to be the most reliable and accurate of all scoring systems so far devised. It is widely applicable in other specialities as it allows comparison based on the patient’s physiological status and the magnitude of surgery. It could be used in any hospital, in elective and emergency operations. The present study attempted to validate the application of this new method of assessing the outcome after orthopaedic surgery. All consecutive patients admitted to the orthopaedic wards in a district general hospital during a 12 month period in which orthopaedic surgery was performed on a non-day case basis were assessed using the new orthopaedic POSSUM system. POSSUM is an acronym for During the 12 month period The present study indicates that orthopaedic POSSUM is accurate in assessing outcome after an orthopaedic operation and can be used as an audit aid to assess the quality of surgical care.
Recently concerns have been raised as to the effect of intra-articular radio-frequency energy on axillary nerve function. In our unit 120 shrinkage procedures have been performed with 5 intra-operative contractions of deltoid and no axillary nerve palsy. In this study we aimed to identify and quantify any changes in axillary nerve function following capsular shrinkage. Needle electrodes were inserted into the deltoid muscle of 10 patients undergoing radio-frequency capsular shrinkage and 3 patients having diagnostic arthroscopy. Recordings of Compound Muscle Action Potentials (CMAPs) were made following pre-operative magnetic coil stimulation of the axillary nerve. The nerve was then monitored during operation. At the end of the procedure, a further recording of CMAP following axillary nerve stimulation was made to allow comparison with initial readings. We have shown:
Low amplitude stimulations of the axillary nerve in 6 of the 10 patients undergoing shrinkage. Increase in latency of the axillary nerve was noted in some patients including the controls. Increase in latency was independent of time spent performing shrinkage. We have concluded:-
Stimulation of the axillary nerve occurs frequently during capsular shrinkage. This axillary nerve stimulation cannot be causally related to the application of radio-frequency energy. Increased latency may occur due to cooling of the nerve by extravasated irrigation fluid. Nerve monitoring is recommended during the training of surgeons new to this technique. We would like to acknowledge the Magstim Company for their assistance with this project.
The role of matrix metalloproteinases (MMPs) in the aseptic loosening of hip prostheses is well established. Gelatinase MMPs have been identified in the interface membranes and the pseudosynovial tissues in the hips. Little data are available on gelatinase MMPs and their major regulators, including specific tissue inhibitors of matrix metalloproteinases (TIMPs) in the loosening of shoulder prostheses. The objectives of this study were to determine whether A) gelatinase MMPs and their regulators (MMP14, TIMP-1,-2) are produced by periprosthetic tissues in cases of aseptic loosening of shoulder prostheses, and, B) to identify which cell types, in both interface and synovial tissues, localize the enzymes. Interface tissues and synovial tissues were obtained during revision surgery for loose shoulder implants. In 9 patients (6-Total Shoulder Replacement, 3-Hemiarthro-plasty (Bipolar), 9 samples of interface tissues and 8 samples of synovial tissues were obtained. Of the interface tissues 2 were from the interface of the bipolar and the unresurfaced glenoid. Formalin-fixed paraffin embedded sections were stained using primary antibodies for MMP2 (Neomarkers), MMP9 (Oncogene Ltd), TIMP1, TIMP2 &
MMP14 (Chemicon Ltd). Antigen retrieval required pressure cooker treatment for MMP2 and MMP9 and trypsin for TIMP1. Visualisation used a standard DAB chromagen technique (Envision, Dako Ltd.). Appropriate control sections ensured reproducibility of the staining. The antibodies selected bind to both active and inactive forms of the MMPs. Both HDPE and metal debris were seen in both the synovial and interface tissues. Transformation of macrophages to giant cells was associated with PE debris, and was not observed with metal debris alone. The presence of gelatinase MMPs in both interface and synovial tissues in aseptic loosening of shoulder prostheses was demonstrated. Differences between the MMP content of macrophages and giant cells between the tissues was detected, positivity was associated with the presence of metallic and/or HDPE debris. Activation of endothelial MMP2 by both MMP14 and low levels of TIMP2 would support the development of a vascular network.
The overall incidence of cuff tears increases with age, individuals over 80years having a 51% incidence of a tear. Currently, the aetiology of rotator cuff tears remains unclear and successful repair is achieved in only 30% patients. Matrix metalloproteinases (MMPs) have roles in a wide range of physiological processes including placentation and embryogenesis, tissue remodelling and wound healing. However, the ability of MMPs to dissolve extracellular matrix has been linked to a variety of pathological processes including rheumatoid arthritis, osteoarthritis, periodontitis and multiple sclerosis, which involve excessive matrix destruction. Production of gelatinase MMPs by torn rotator cuff has been demonstrated. The objectives of this study were to examine the expression of MMPs and their association with histological changes in full thickness tears of the rotator cuff. Rotator cuff tissue was obtained from ten patients (age 40–80years) undergoing surgical repair. The size of tear was 1–4.5cm; time from presentation to surgery was 1 month (acute) to between 0.5–4years (chronic). Immunohistochemical staining with commercial monoclonal antibodies to a range of MMPs, endothelial, macrophage and fibroblast markers was performed. Production of gelatinase MMPs was measured by gelatin zymography on tissue culture supernatant. Visualisation used a standard DAB chromagen technique. In the acute specimens there was an infiltrate of macrophages with little collagen degeneration; the fibro-blasts were MMP1 positive and endothelial cells MMP2 positive. At 12 months post-tear mature collagen, plump fibroblasts and proliferating endothelial cells were identified adjacent to the resection edge. Towards the torn edge areas of lower cellularity, sparse vascularity and collagen degeneration were observed. Vimentin positive, CD68 negative cells within this matrix were rounded with foamy cytoplasm, and intensely positive for MMP1 and MMP2, and positive for MMP-3, -10, -11, -13 and -14. Tissue culture supernatant demonstrated active and latent MMP2 production in all cases. The prolonged interval between trauma and surgical repair, with potential pharmacological intervention, remedial physiotherapy and disuse immobility, make assessment of the factors contributing to tendon degeneration difficult to determine. Fatty infiltration, dystrophic calcification and patchy collagen degeneration were common. However, clear evidence of cellular activities typical of wound repair were also identified, including fibroblast and endothelial cell proliferation. The most striking finding was the association between areas of poor collagen structure with fibroblasts staining intensely for both MMP1 and MMP2 and positive for other matrix metalloproteinases. The production of MMP1 and MMP2 may contribute to active remodelling of the tendon matrix. Success of repair could be influenced by both the quality of the matrix and the cell types and activities in the tissue at the resection edge.
