Aims. Complex joint fractures of the lower extremity are often accompanied by soft-tissue swelling and are associated with prolonged hospitalization and soft-tissue complications. The aim of the study was to evaluate the effect of vascular impulse technology (VIT) on soft-tissue conditioning in comparison with conventional elevation. Methods. A total of 100 patients were included in this prospective, randomized, controlled monocentre study allocated to the three subgroups of dislocated ankle fracture (n = 40), pilon fracture (n = 20), and intra-articular calcaneal fracture (n = 40). Patients were randomized to the two study groups in a 1:1 ratio. The effectiveness of VIT (intervention) compared with elevation (control) was analyzed separately for the whole study population and for the three subgroups. The primary endpoint was the time from admission until operability (in days). Results. The mean length of time until operability was 8.2 days (SD 3.0) in the intervention group and 10.2 days (SD 3.7) in the control group across all three fractures groups combined (p = 0.004). An analysis of the subgroups revealed that a significant reduction in the time to operability was achieved in two of the three: with 8.6 days (SD 2.2) versus 10.6 days (SD 3.6) in ankle fractures (p = 0.043), 9.8 days (SD 4.1) versus 12.5 days (SD 5.1) in pilon fractures (p = 0.205), and 7.0 days (SD 2.6) versus 8.4 days (SD 1.5) in calcaneal fractures (p = 0.043). A lower length of stay (p = 0.007), a reduction in pain (p. preop. = 0.05; p. discharge. < 0.001) and need for narcotics (p. preop. = 0.064; p. postop. = 0.072), an increased reduction in swelling (p < 0.001), and a lower revision rate (p = 0.044) could also be seen, and a trend towards fewer complications (p = 0.216) became apparent. Conclusion. Compared with elevation, VIT results in a significant reduction in the time to achieve operability in complex joint fractures of the lower limb. Cite this article: Bone Joint J 2021;103-B(4):746–754

Swelling following an ankle fracture is commonly believed to preclude surgical fixation, delaying operative treatment to allow the swelling to subside. This is in an attempt to achieve better soft tissue outcomes. We aim to identify whether pre-operative ankle swelling influences postoperative wound complications following ankle fracture surgery. This is a prospective cohort study of 80 patients presenting to a tertiary referral centre with operatively managed malleolar ankle fractures. Ankle swelling was measured visually and then quantitatively using the validated ‘Figure-of-eight’ technique. Follow-up was standardised at 2, 6, and 12 weeks post-operatively. Wound complications, patient co-morbidities, operative time, surgeon experience, and hospital stay duration were recorded. The complication rate was 8.75% (n=7), with 1 deep infection requiring operative intervention and all others resolving with oral antibiotics and wound cares. There was no significant difference in wound complication rates associated with quantitative ankle swelling (p=0.755), visual assessment of ankle swelling (p=0.647), or time to operative intervention (p=0.270). Increasing age (p=0.006) and female gender (p=0.049) had a significantly greater probability of wound complications. However, BMI, smoking status, level of the operating surgeon, and tourniquet time were not significantly different. Visual assessment of ankle swelling had a poor to moderate correlation to ‘Figure-of-eight’ ankle swelling measurements ICC=0.507 (0.325- 0.653). Neither ankle swelling nor time to surgery correlates with an increased risk of postoperative wound complication in surgically treated malleolar ankle fractures. Increasing patient age and female gender had a significantly greater probability of wound infection, irrespective of swelling. Visual assessment of ankle swelling is unreliable for quantifying true ankle swelling. Operative intervention at any time after an ankle fracture, irrespective of swelling, is safe and showed no better or worse soft tissue outcomes than those delayed for swelling

Knee swelling is common after injury or surgery, resulting in pain, restricted range of movement and limited mobility. Accurately measuring knee swelling is critical to assess recovery. However, current measurement methods are either unreliable or expensive [1,2]. Therefore, a new measurement method is developed. This wearable (the ‘smart brace’) has shown the ability to distinguish a swollen knee from a not swollen knee using multi-frequency-bio impedance analysis (MF-BIA) [3]. This study aimed to determine the accuracy of this smart brace. The study involved 25 usable measurements on patients treated for unilateral knee osteoartritis with a 5mL injection of Lidocaïne + DepoMedrol (1:4). MF-BIA measurements were taken before and after the injection, both on the treated and untreated knee. The smart brace accurately measured the effect of the injection by a decrease in resistance of up to 2.6% at 100kHz (p<0.01), where commonly used gel electrodes were unable to measure the relative difference. Remarkably, both the smart brace and gel electrodes showed a time component in the MF-BIA measurements. To further investigate this time component, 10 participants were asked to lie down for 30 minutes, with measurements taken every 3 minutes using both gel electrodes and the smart brace on both legs. The relative change between each time step was calculated to determine changes over time. The results showed presence of a physiological aspect (settling of knee fluids), and for the brace also a mechanical aspect (skin-electrode interface) [4]. The mechanical aspect mainly interfered with reactance values. Overall, the smart brace is a feasible method for quantitatively measuring knee swelling as a relative change over time. However, the skin-electrode interface should be improved for reliable measurements at different moments in time. The findings suggest that the smart brace could be a promising tool for monitoring knee swelling during rehabilitation

Abstract. Decellularised porcine superflexor tendon (pSFT) provides an off-the-shelf, cost-efficient option for ACL reconstruction (ACLR). During decellularisation, phosphate buffered saline (PBS) is used for washing out cytotoxic solutes and reagents, maintaining tissue hydration. It has been shown to increase water content in tendon, swelling the tissue reducing mechanical properties. End stage PBS washes in the standard protocol were substituted with alternative solutions to study tissue swelling and its impact on the mechanical behaviour and matrix composition of pSFTs. 25%, 100% Ringers and physiological saline test groups were used (n=6 for all groups). pSFTs were subject to tensile and confined compression testing. Relative hydroxyproline (HYP), glycosaminoglycan (GAG) and denatured collagen content (DNC) were quantified. Modified decellularised tendon groups were compared to tendons decellularised using the standard protocol and native tendons. Specimen dimensions reduced (p=0.004) post-decellularisation only in 25% Ringers group. In all other modified groups, less swelling was apparent but not statistically different from standard group. Only 25% Ringers group had higher linear modulus (p=0.0035) and UTS (p=0.013) compared to standard group. All decellularised groups properties were reduced compared to native pSFTs. Stress relaxation properties showed a significant reduction in decellularised groups compared to native. Compression testing showed no significant differences in peak stress for modified decellularised groups compared to native. A reduction (p=0.036) was observed in standard group. Quantification of GAGs and DNC showed no significant differences between groups. HYP content was higher (p<0.0001) for saline group. A significant reduction in tissue swelling could be related to improved mechanical properties of decellularised pSFTs. Alternative solutions in end stage washes had no significant effect on quantities of matrix components, but altered structure/function could explain the differences in tensile and compressive behaviour, and should be further studied. In all decellularised groups, pSFTs retained suitable mechanical properties for ACLR

Patients awaiting resolution of swelling and oedema prior to ankle surgery can represent a significant burden on hospital beds. Our study assessed whether external pneumatic intermittent compression (EPIC) can reduce delays to surgery. Our prospective randomised controlled trial (n= 20) compared outcomes of patients treated with EPIC vs control group managed with ice and elevation. Included were patients aged <18 years with isolated closed ankle fractures admitted for management of swelling prior to surgery. Excluded were open fractures, injuries to contralateral leg, diabetes, absent pulses, peripheral vascular disease, inability to consent, no requirement for admission. Eligible patients were randomised to active or control arms. All patients were managed initially with reduction and back slab application. Patients in active arm fitted with EPIC (Hydroven 3000) device over the back slab. Assessment by treating team determined the time at which patient is assessed ready for surgery. Patients in the treatment arm were assessed as ready for surgery sooner, (123 hrs vs 168hrs, T score = 1.925, P 0.035) and had a shorter time to surgery (167 hrs vs 216 hrs, T score = 1.748, P 0.047) Length of stay was reduced bud did not reach statistical significance. (259 hrs vs 269 hrs, T score 0.229, P 0.41). Our results showed a statistically and clinically significant reduction in time that patients were assessed ready for surgery and time to surgery in the treatment cohort. We conclude that although further data is needed to achieve an adequately powered study and assess the safety profile of the EPIC, incorporation of EPIC into routine clinical practice has the potential for significant cost savings

Abstract. Objectives. Osteoarthritis (OA) is a complex joint disorder characterised by the loss of extracellular matrix (ECM) leading to cartilage degeneration. Changes to cartilage cell (chondrocyte) behaviour occur including cell swelling, the development of fine cytoplasmic processes and cell clustering leading to changes in cell phenotype and development of focal areas of mechanically-weak fibrocartilaginous matrix. [1]. To study the sequence of events in more detail, we have investigated the changes to in situ chondrocytes within human cartilage which has been lightly scraped and then cultured with serum. Methods. Human femoral heads were obtained with Ethical permission and consent from four female patients (mean age 74 yrs) undergoing hip arthroplasty following femoral neck fracture. Osteochondral explants of macroscopically-normal cartilage were cultured as a non-scraped control, or scraped gently six times with a scalpel blade and both maintained in culture for up to 2wks in Dulbecco's Modified Eagle's Medium (DMEM) with 25% human serum (HS). Explants were then labelled with CMFDA (5-chloromethylfluorescein-diacetate) and PI (propidium iodide) (10μM each) to identify the morphology of living or dead chondrocytes respectively. Explants were imaged using confocal microscopy and in situ chondrocyte morphology, volume and clustering assessed quantitatively within standardised regions of interest (ROI) using Imaris. ®. imaging software. Results. Within 2wks of culture with HS, chondrocyte volume increased significantly from 412±9.3µm. 3. (unscraped) at day 0 to 724±16.6 µm. 3. (scraped) [N(n) = 4(380)] (P=0.0002). Chondrocyte clustering was a prominent feature of HS culture as the percentage of clusters in the cell population increased with scraping from 4.8±1.4% to 14.9±3.9% [N(n) = 4(999)] at week 2 (P=0.0116). In addition, the % of the chondrocyte population within clusters increased from approximately 38% to 60%, and the number of cells per cluster increased significantly from 3.2±0.08 to 4±0.22 (P=0.031). The development of abnormal ‘fibroblastic-like’ chondrocyte morphology demonstrating long (>5µm) cytoplasmic processes also occurred, however the time course of this was more variable. For some samples, clustering occurred before abnormal morphology, but for others the opposite occurred. Typically, by the second week, 17±2.64% of the cell population had processes and this increased to 22±4.02% [N(n) = 4(759)] with scraping. Conclusions. Scraping the cartilage will remove surface constituents including lubricants (e.g. lubricin, hyaluronic acid, phospholipids), extracellular matrix constituents (collagen, proteoglycans – potentially the ‘lamina splendens’) and cells (chondrocytes and mesenchymal stromal cells (MSCs)). Although we do not know which of these component(s) is important, the effect is to dramatically increase the permeation of serum factors into the cartilage matrix and signal the development of cytoplasmic processes, cell clustering and swelling. It is notable that these cellular changes are similar to those occurring in early OA. [1]. This raises the interesting possibility that scraped cartilage cultured with human serum recapitulates some of the changes to in situ chondrocytes during early stages of cartilage degeneration and as such, could be a useful model for following the deleterious changes to matrix metabolism. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Objectives. A fibril reinforced multiphasic cartilage model was developed to improve the understanding of the depth-dependent cartilage internal structure and its through thickness biomechanical response. The heterogeneous model of cartilage was validated against full-field strain measurement obtained via Digital Image Correlation (DIC) during free swelling experiments. Methods. Hemi-cylindrical cartilage cores of 5mm diameter were obtained from porcine femoral condyles and humeral heads. The full field behaviour of these samples was monitored using DIC during an osmotic free swelling experiment performed following a standardised protocol [1]. Computational models were created in FEBio (version 2.8, . febio.org. ). The cartilage, submerged in saline solution was represented by a 1×1mm cube [2] with geometry and constrains set up to mimic the experimental conditions. Cartilage was modelled as a multiphasic material represented by one inhomogeneous layer with depth-dependent Young's modulus [3], zonally varied water content and zonally oriented collagen fibrils [4]. Experimental and predicted strain maps were compared to each other both qualitatively and quantitatively. Results. The numerical strain map showed high strain localisation close to the cartilage surface, with strain in this region reaching 40% and 12% for femoral and humeral samples respectively, this finding was confirmed in our experimental results. Strain magnitude gradually decreased with depth, reaching near-zero at around 200μm. This behaviour also matched experimental observations. Conclusions. Both sets of computational strain results exhibited very good agreement with experimental data, both in terms of cartilage through-thickness swelling behaviour and strain magnitude. Our results show the importance of including cartilage structural inhomogeneities and inclusions of collagen fibrils when simulating through-thickness cartilage swelling. These findings highlight the crucial role of collagen fibrils on both tissue solute transport properties as well as the overall biomechanical response of cartilage. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Patients often comment on swelling after foot and ankle surgery. However the relationship between swelling and outcome (pain and function) has not previously been outlined. A recent study by Pinsker and Daniels demonstrated that while swelling was rated as important by patients it was rarely included in outcome scores. The purpose of this paper was to determine the relationship between swelling and outcome after ankle fusion or replacement. A secondary purpose was to determine how this relationship changed in time, how swelling score changed before and after surgery, and determine differences in swelling score between total ankle replacement (TAR), open ankle arthrodesis (OAA) and arthroscopic ankle arthrodesis (AAA). The COFAS prospective ankle arthritis database enrolls patients in 4 centers undergoing surgery by one of 6 surgeons since 2002. The MODEMS outcomes package from AAOS was used, with the validated ankle osteoarthritis score (AOS) score being used to assess outcomes in the pain and disability domains. The swelling score was indexed from 1 to 5, 1 being no swelling and 5 being severe swelling. Outcomes were recorded preoperatively and annually up to 2010. Statistical analysis was performed using 95% confidence intervals and correlations being determined using Pearson's correlation and r2 values. The swelling score was correlated with AOS score with an r2 of 0.13 for postoperative patients. With the swelling score analysed categorically the difference of outcome was significant with a mean AOS score of 15.1 (CI 13.3 to 16.9) for a swelling score of 1, 23 (CI 21.7 to 24.9) for a swelling score of 2, 31 (CI 29.6 to 33.1) for 33.6 (CI 34.9 to 38.8) for 4, and 39 (CI 35.3 to 43.0) for 5. Swelling scores fell outside the 95% confidence intervals for all groups indicating that the AOS outcome of swelling score 5 patients was worse than the 4 group, 4 worse than 3, 3 worse than 2, and 2 worse than 1. Patients with swelling scores of 1 scored 24 points better than those with a swelling score of 5. Swelling scores were the same preoperatively for total ankle arthroplasty, Arthroscopic and open fusions. However swelling scores were lower for arthroscopic fusions after surgery for all time periods at an average of 2.1 (CI 1.9 to 2.2), compared to total ankle arthroplasty (2.5, CI 2.4 to 2.6) and open ankle fusion (2.5, CI 2.4 to 2.6). Swelling has a major relationship with outcome. Swelling may be the cause of poorer outcomes for open ankle fusion compared to arthroscopic. Swelling is an independent factor as swelling scores for TAA were higher compared to AAA despite similar outcomes. Arthroscopic surgery reduces the postoperative swelling. Methods to reduce swelling such as compression stockings, elevation, controlling bleeding may result in better outcomes. Minimising the invasiveness of surgery achieves this goal. Patient education about swelling, elevation and compression stockings would assist in these goals

Aim. Prospectively assess the degree of finger swelling after shoulder arthroscopy, to determine whether rings should be routinely removed prior to surgery. Method and Results. Patients undergoing shoulder arthroscopic procedures had finger diameters measured prior and post surgery, over a three month period. The study was approved by our Research and Development department. Measurements were taken using a finger circumference gauge (Southpointe, Florida, USA) and were all performed by one researcher in a standard technique, to eliminate inter observer variability. Control measurement, using the contralateral hand, were taken. Statistical analysis was performed, using the Mann Whitney U test. 31 patients undergoing shoulder arthroscopy were included in the study and had finger diameters assessed. The median amount of finger swelling on the operated side was 2.8 mm (IQR 4.6) per digit, compared to 0 mm on the contralateral side (IQR 1.6), which was significantly greater (p=0.0003). There was no statistical difference in the amount of finger swelling when patients undergoing short procedures (less than 30 minutes operating time) were compared to patients undergoing long procedures (greater than 60 minutes). Conclusions. These results suggest that patients undergoing shoulder arthroscopy have a significant degree of finger swelling post-operatively and that the amount of swelling cannot be accurately predicted based on the length of procedure alone. This indicates that rings should be routinely removed, prior to shoulder arthroscopy, even if this necessitates cutting of rings for removal

Background. Total knee arthroplasty (TKA) is offered to patients who have end-stage knee osteoarthritis to reduce pain and improve functional performance. Knee edema and pain deteriorate the patients' outcomes after TKA at early period. By quantifying the patients' early outcome deficits and their potential relationships to edema and pain may assist in the design of in-patient rehabilitation programs. Objectives. The aim of this study was to investigate of the effect of knee swelling on early patients' outcomes after primary TKA. Design and Methods. The study group consisted of 61 patients (10 males, 51 females), who underwent primary TKR because of knee arthrosis were included in the study with mean age 65.2±9 years. Patients were evaluated regarding knee circumference (10 cm superior of midpoint of patella, midpoint of patella, 10 cm distal of midpoint of patella), pain (Numeric Pain Rating Scale (NPRS)), knee range of motion (ROM), the day of active straight leg raise, knee function score (Hospital for Special Surgery (HSS)), Functional activities were evaluated using the Iowa Level of Assistance Scale (ILAS) and walking speed was evaluated using the Iowa Ambulation Velocity Scale (IAVS). Results. There were moderate significant correlation between knee circumference (10 cm superior of midpoint of patella; r=0.328, p=0.001, midpoint of patella; r=0.310, p=0.002, 10 cm distal of midpoint of patella; r=0.300, p=0.003) and IAVS. While, significant low correlation was found between pain level and knee ROM (r=−0.272, p=0.008), there was strong significant correlation between pain level and HSS (r=0.866, p<0.001). There was not significant correlation between knee swelling and all the other measurement, and also between pain and all the other measurement (p>0.05). Conclusion. The moderate correlation between knee swelling and IVAS, low correlation between pain and knee ROM, and also strong correlation between pain and HSS suggests that improved postoperative knee swelling and pain could be important to enhance the potential benefits of TKA in early stage. With improvement in knee swelling and pain the patient may obtain good functional outcomes and knee score

The August 2023 Wrist & Hand Roundup360 looks at: Complications and patient-reported outcomes after trapeziectomy with a Weilby sling: a cohort study; Swelling, stiffness, and dysfunction following proximal interphalangeal joint sprains; Utility of preoperative MRI for assessing proximal fragment vascularity in scaphoid nonunion; Complications and outcomes of operative treatment for acute perilunate injuries: a systematic review; The position of the median nerve in relation to the palmaris longus tendon at the wrist: a study of 784 MR images; Basal fractures of the ulnar styloid? A randomized controlled trial; Proximal row carpectomy versus four-corner arthrodesis in SLAC and SNAC wrist; Managing cold intolerance after hand injury: a systematic review

Aims. The aim of this study was to determine whether closed suction drain (CSD) use influences recovery of quadriceps strength and to examine the effects of drain use on secondary outcomes: quadriceps activation, intra-articular effusion, bioelectrical measure of swelling, range of movement (ROM), pain, and wound healing complications. Patients and Methods. A total of 29 patients undergoing simultaneous bilateral total knee arthroplasty (TKA) were enrolled in a prospective, randomized blinded study. Patients were randomized to receive a CSD in one limb while the contralateral limb had the use of a subcutaneous drain (SCDRN) without the use of suction (‘sham drain’). Isometric quadriceps strength was collected as the primary outcome. Secondary outcomes consisted of quadriceps activation, intra-articular effusion measured via ultrasound, lower limb swelling measured with bioelectrical impendence and limb girth, knee ROM, and pain. Outcomes were assessed preoperatively and postoperatively at day two, two and six weeks, and three months. Differences between limbs were determined using paired Student’s t-tests or Wilcoxon’s signed-rank tests. Results. No significant differences were identified between limbs prior to surgery for the primary or secondary outcomes. No significant differences in quadriceps strength were seen between CSD and SCDRN limbs at postoperative day two (p = 0.09), two weeks (primary endpoint) (p = 0.7), six weeks (p = 0.3), or three months (p = 0.5). The secondary outcome of knee extension ROM was significantly greater in the CSD limb compared with the SCDRN (p = 0.01) at two weeks following surgery, but this difference was absent at all other intervals. Secondary outcomes of quadriceps activation, intra-articular effusion, lower limb swelling, and pain were not found to differ significantly at any timepoint following surgery. Conclusion. The use of CSD during TKA did not influence quadriceps strength, quadriceps activation, intra-articular effusion, lower limb swelling, ROM, or pain. These results have limited drain use by the authors in primary uncomplicated TKA. Cite this article: Bone Joint J 2019;101-B (7 Supple C):84–90

Introduction: Hip resurfacing has been increasingly used procedure for physiologically young and active patients. Wear properties of the implants are considered to be excellent. We present a case of tumor like swelling of the thigh following metal on metal hip resurfacing. Case report: 56 year old lady underwent metal on metal hip resurfacing for idiopathic osteoarthritis of right hip. Implant size: 38 mm head with 44 mm cup. After 18 months of successful surgery she presented with short duration (2 weeks) history of thigh swelling with pain and stiffness in hip and knee. Clinically gross circumferential swelling of right thigh from inguinal ligament to the knee joint. She had increased serum cobalt chromium levels. Aspiration of hip revealed high levels of cobalt and chromium. Biopsy and intra operative samples at revision revealed “no infection or tumor but non specific inflammatory reaction.”. The patient underwent revision surgery to ceramic-plastic bearing.(THR). 12 months post operative, the swelling has reduced with painless mobile hip and knee joints. Discussion: The metal on metal hip resurfacing could have produced high metal ion wear reaction leading to swelling. Which could be because of small diameter prosthesis with valgus position of femoral component with open cup angle of 49 degrees

Introduction: Ankle fractures are among the commonest orthopaedic injuries. A delay in operating is often due to the swelling associated with such fractures. On the other hand, the delay in operative fixation beyond 24 h from injury is associated with a lengthening of hospital stay which costs approximately £225 per patient per day for an acute trauma bed. Objectives: The aim of this study was to analyse the relationship between the delay in surgical intervention of open reduction and internal fixation of ankle fractures from presentation due to ankle swelling, and the length of hospital stay and postoperative complications. Patients and Methods: A retrospective study of 145 consecutive patients treated for ankle fractures over a period of 12 months between January and December 2008. results were collated excluding talar and pilon fractures. Emergency department presentation times were noted and time of anaesthetic to determine surgical delay. Notes were reviewed for inpatient stay and postoperative complications. Results: There were 62 male and 83 female patients with a mean age of 49 years. In total, 117 (80%) patients were operated on within 24 hours of presentation (early group). 28 patients’ surgery was delayed beyond 24 hours (delayed group). Of the 117 patients the mean inpatient stay was 3.79 days (± 2.39) whereas in the delayed group the mean stay was 8.57 days (± 6.54). Of the delayed group, 57% of the cases had swelling as the cause of a postponed operation, whereas other causes included lack of theatre time and lack of fitness for surgery. In the early group, 5 patients (4.27%) had wound infections and one patient had a chest infection (0.85%). Four patients (14.28%) from the delayed group developed wound infections all of whom were from patients with ankle swelling. Conclusion: We recommend that policies be put in place to provide early operative intervention for patients with fractured ankles prior to the development of swelling as this would result in improved patient outcome and significant financial savings. If an operation is not feasible within 24 hours of admission and the ankle is swollen resulting in a high operative risk, we recommend sending the patient home for a period of 5–7 days with advice on RICE and anticoagulation which would both permit surgery and cut down costs

Patient specific knee modelling has the potential to help understand the development of the mechanically induced degenerative disease, Osteoarthritis. A full joint contact model of the knee involves modelling the bones, ligaments, articular cartilage (AC) and meniscus, as well as, the kinematics and geometry of real joints. These finite element models will inevitably require great computational resource to run and it is desirable to find resource effective material model formulations which can accurately describe the mechanical behaviour of the soft tissues. Biphasic models (BIMs) have long been established as an effective formulation for modelling AC. However, the swelling behaviour caused by changes in the ionic phase is a major recovery mechanism and is neglected in the BIMs. It is therefore believed that BIMs alone are insufficient to fully describe the mechanical behaviour of AC. Instead, a thermal analogy method which is generically a BIM that includes the swelling behaviour has been thought to be suitable and has been validated against literature data using material parameters optimized to match the numerical and experimental results. To ensure the model is suitable for patient specific modelling where it will have the ability to reflect the individual AC material properties of the patients in the mechanical behaviour it predicts, two experiments have been planned and are currently being carried out using bovine AC. The first experiment is to investigate the diffusivity of the tissue in solutions of different molarity by measuring the change in tissue weight over time. Eleven explants are taken from the same bovine articular joint using a 6mm biopsy punch and are left in 10mM of PBS overnight to ensure ionic equilibrium has been reached before experiments are carried out. The explants are then placed in PBS solutions of molarities ranging from 0mM to 10mM and weighed at regular time intervals. In the final stage, the explants are then lyophilized and weighed for determining the volume of water in the tissues. Using Archimedes principle, the change in porosity of the tissue is found. A preliminary study has shown that explants submerged in a solution of 5mM has an approximately 4% change in weight after the first 24h and a further 1.73% change in the following 24h. Control specimens left in a solution of 10mM had a 0% change in weight. The second experiment is to carry out mechanical loading on the AC specimens while submerged in a solution of different ion concentrations. Experiments with various loading conditions are being investigated to explore their efficacy for validation. Preliminary compression tests have been carried out where steps of 1% strain was applied, giving a total of 10% strain. Between each step, strain was held constant until full relaxation has been achieved. The reaction force measured from the second experiment in conjunction with data collected from the first experiment will be compared to results predicted in the numerical model. This will allow the determination of whether thermal analogy is adequate or whether more complex triphasic models need to be considered. Furthermore, the development of these experimental methods will contribute to the validation of other AC material models in the future

Postoperative leg swelling after a total knee replacement is common complaint amongst patients. We studied leg swelling by constructing a novel, simple and cost water volumeter. A pilot study was conducted on 15 volunteers by two observers and each observer took a total of three readings. The mean intraobserver variation was 0.2 percent and mean interobserver variation was 0.3 percent, indicating a highly acceptable level of accuracy. The water volumeterwas then used in a randomized prospective study was conducted to determine the relationship between postoperative leg swelling and Fraxiparine, a low molecular weight heparin. From the period of 1st January 2000 till 31th October 2000, a total of 36 patients were enrolled in the study. 18 patients in the study group received fraxiparine and 18 patients in the control group did not. The leg volume was measured preoperatively and on postoperative days 5, 7 and 10. We found that both groups developed maximum swelling at postoperative day 5 and this decreased to almost normal at day 10. However the fraxiparine group was statistically less swollen (4%) than the control group (10%) on day 5 and also on day 7 (−0.2% vs 7%). These findings were independent of whether the patient underwent bilateral or unilateral surgery. We conclude that low molecular weight heparins are effective in reducing postoperative leg swelling in total knee replacement

Introduction. Excessive soft tissue swelling will delay surgery for a proportion of patients admitted with ankle fractures. Surgical and anesthetic teams may waste time assessing patients destined to be cancelled due to swelling. The aim of this investigation was to determine factors associated with cancellation. Methods. Case notes of 87 patients (46 male, 41 female), mean age 43 years (range, 13 to 80) who underwent ankle fracture fixation were retrospectively analysed. 31 of 87 ankles (36%) were unsuitable for day after admission surgery due to swelling. Factors investigated included age, gender, mechanism of injury, fracture configuration and necessity for reduction on arrival in the emergency department due to dislocation; each factor was independently analysed for significance using Fisher's exact test. Results. Ankle fractures associated with a higher energy injury such as sports, falls from height and road traffic accidents were significantly more likely than simple slips to be cancelled due to excess swelling the following morning (p = 0.053). Tri- or bi-malleolar ankle injuries and fracture dislocations requiring manipulation in the emergency department were also significant risk factors for cancellation (p = 0.004 and p = 0.002 respectively). Patients presenting with at least two of these factors demonstrated a 71% probability of cancellation the following day (17 of 87 patients). Presence of three risk factors increased the probability of cancellation to 100% (3 of 87 patients). Conclusion. Cancellation on the day of surgery wastes time and causes patient distress. During busy on-call periods patients with all three risk criteria will almost certainly be too swollen for next day surgery. With the proviso that these fractures are immobilised in an acceptable position, patients could be rested with elevation and rebooked for surgery as opposed to being assessed and subsequently cancelled due to soft tissue swelling the day after injury

Introduction and Aims: A variety of factors have been associated with difficulty in regaining normal knee motion following anterior cruciate ligament surgery. The purpose of this study was to determine if increased swelling in the early post-operative period is predictive of difficulty in regaining full range of motion after ACL reconstruction. Method: 118 consecutive patients were prospectively assessed post-ACL reconstruction. Range of motion was measured by goniometer at week one, four and eight. A deficit greater than 10 degrees of flexion or five degrees of extension (compared to normal leg) at the eight-week mark were defined as significant. The grade of hemarthrosis and circumference of the leg at the level of the patella were recorded at the same intervals. All patients underwent endoscopic, primary, ACL reconstruction with a standardised post-op physio protocol. Exclusion criteria included previous surgery on either knee, significant effusion at the time of surgery or associated ligament injuries. Results: Patients with a higher grade of hemarthrosis at one week were more likely to have a flexion deficit at eight weeks (P=0.002, relative risk 1.93). Increased circumference was also associated with a flexion deficit at eight weeks (P=0.007, relative risk 1.37). The presence of a large hemarthrosis was not associated with an extension deficit at (P=0.47), although there was a trend for increased circumference to be associated with extension deficit (P=0.07). The patients that had difficulty in regaining full range of motion were similar to the rest of the cohort with regards to patient age, sex, time to surgery, graft type, incidence and treatment of meniscal pathology. Conclusions: Increased swelling, at one-week post-op (presence of a large hemarthrosis or a measured circumference greater than 1.5cm more than the control limb) is associated with flexion loss at eight weeks post-surgery. These patients merit closer observation and possibly a modified rehabilitation protocol

Range of motion, degree of hemarthrosis and leg circumference was prospectively recorded in one hundred and eighteen consecutive isolated ACL reconstructions. A higher grade of hemarthrosis at one week was associated with a flexion deficit at eight weeks (P=0.002, relative risk 1.93). Increased leg circumference at one week was also associated with a flexion deficit at eight weeks (P=0.007, relative risk 1.37). An extension deficit was not associated with a hemarthrosis (P=0.47) or increased circumference (P=0.07). This prospective review identifies a risk factor for clinicians to be aware of after ACL Reconstruction. These patients merit closer observation and possibly a modified rehabilitation protocol. To determine if increased swelling in the early post operative period is predictive of difficulty in regaining full range of motion after ACL reconstruction. Increased swelling, at one-week post op (presence of a large hemarthrosis or a measured circumference greater than 1.5cm more than the control limb) is associated with flexion loss at eight weeks post surgery. These patients merit closer observation and possibly a modified rehabilitation protocol. Patients with a higher grade of hemarthrosis at one week were more likely to have a flexion deficit at eight weeks (P=0.002, relative risk 1.93). Increased circumference was also associated with a flexion deficit at eight weeks (P=0.007, relative risk 1.37). The presence of a large hemarthrosis was not associated with an extension deficit at (P=0.47) although there was a trend for increased circumference to be associated with extension deficit (P=0.07). One hundred and eighteen consecutive patients were prospectively assessed post ACL reconstruction. Range of motion was measured by goniometer at week one, four and eight. A deficit greater than 10° of flexion or 5° of extension (compared to normal leg) at the eight-week mark was defined as significant. The grade of hemarthrosis and circumference of the leg at the level of the patella were recorded at the same intervals. All patients underwent endoscopic, primary, ACL reconstruction with a standardized post op physio protocol. Exclusion criteria included previous surgery on either knee, significant effusion at the time of surgery or associated ligament injuries

Introduction. Physical disruption of the extracellular matrix influences the mechanical and chemical environment of intervertebral disc cells. We hypothesise that this can explain degenerative changes such as focal proteoglycan loss, impaired cell-matrix binding, cell clustering, and increased activity of matrix-degrading enzymes. Methods. Disc tissue samples were removed surgically from 11 patients (aged 34–75 yrs) who had a painful but non-herniated disc. Each sample was divided into a pair of specimens (approximately 5mm. 3. ), which were cultured at 37°C under 5% CO. 2. One of each pair was allowed to swell, while the other was restrained by a perspex ring. Live-cell imaging was performed with a wide field microscope for 36 hrs. Specimens were then sectioned at 5 and 30 μm for histology and immunofluorescence using a confocal microscope. Antibodies were used to recognise free integrin receptor α5β1, matrix metalloprotease MMP-1, and denatured collagen types I-III. Proteoglycan content of the medium, analysed using the colorimetric DMMB assay, was used to assess tissue swelling and GAG loss. Constrained/unconstrained results were compared using matched-pair t-tests. Results. Time-lapse cinematography revealed small cell movements in unconstrained specimens, for up to 12 hrs. By 36 hrs, unconstrained (free swelling) samples showed greater: loss of GAG's (p<0.003), loss of integrin binding (p<0.02), synthesis of MMP-1 (p<0.03), and collagen denaturation (p<0.009). Cell clustering was evident in all tissues after 36 hrs. Conclusion. Swelling of disrupted disc tissue disturbs cell-matrix binding, increases matrix degradation, and allows increased proteoglycan loss. This sequence of events could follow disc injury or herniation in-vivo