Total Knee Arthroplasty (TKA) improves the quality of life of osteoarthritic and rheumatoid arthritis patients, however, is associated with moderate to severe postoperative pain. There are multiple methods of managing postoperative pain that include epidural anesthesia but it prevents early mobilization and results in postoperative hypotension and spinal infection. Controlling local pain pathways through intra-articular administration of analgesics is a novel method and is inexpensive and simple. Hence, we assess the effects of postoperative epidural bupivacaine injection along with intra-articular injection in total knee replacement patients. The methodology included 100 patients undergoing TKA randomly divided into two groups, one administered with only epidural bupivacaine injection and the other with intra-articular cocktail injection. The results were measured based on a 10-point pain assessment scale, knee's range of motion (ROM), and Lysholm knee score. The VAS score was lower in the intra-articular cocktail group compared to the bupivacaine injection group until the end of 1-week post-administration (p<0.01). Among inter-group comparisons, we observed that the range of motion was significantly more in cocktail injection as compared to the bupivacaine group till the end of one week (p<0.05). Lysholm's score was significantly more in cocktail injection as compared to the bupivacaine group till the end of one week (p<0.05). Our study showed that both epidural bupivacaine injection and intra-articular injection were effective in reducing pain after TKA and have a comparable functional outcome at the end of 4 weeks follow up. However, the pain relief was faster in cases with intra-articular injection, providing the opportunity for early rehabilitation. Thus, we recommend the use of intra-articular cocktail injection for postoperative management of pain after total knee arthroplasty, which enables early rehabilitation and faster functional recovery of these patients

Background. Epidural steroid injections can provide temporary relief of symptoms in the treatment of lumbar spinal stenosis. Surgery is indicated when conservative measures fail. We hypothesise that patients who gain temporary relief of symptoms from the administration of epidural steroid injections are more likely to result in an improvement in symptoms following surgical intervention compared to patients who do not respond to injection therapy. Method. The records of patients who had received both an epidural injection and surgical intervention for lumbar spinal stenosis between July 2008 and July 2010 were identified and retrospectively reviewed. Relief of symptoms following epidural injection was noted at 6 weeks post procedure and the patients symptoms following surgical intervention was noted and classified according to MacNab's criteria at 3 months post-surgery. Results. 60 patients who received both an epidural injection and surgical intervention for lumbar spinal stenosis were identified. 76% of patients who gained relief of symptoms from epidural injection scored good or excellent according to MacNab's criteria following surgery (n=34). Only 30% of patients who did not respond to injection therapy scored good or excellent according to MacNab's criteria following surgical intervention (n=5). Conclusion. Patients who gained temporary relief of symptoms from epidural injection were more likely to benefit from surgical intervention in the treatment for lumbar spinal stenosis. No conflicts of interest. No funding obtained. We confirm that this abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting

The current study aims to find the role of Enhance Recovery Pathway (ERP) as a multidisciplinary approach aimed to expedite rapid recovery, reduce LOS, and minimize morbidity associated with Non Fusion Anterior Scoliosis Correction (NFASC) surgery. A retrospective analysis of 35 AIS patients who underwent NFASC with Lenke 1 and Lenke 5 curves with a minimum of 1 year of follow-up was done. Patient demographics, surgical details, postoperative analgesia, mobilization, length of stay (LOS), patient satisfaction survey score with respect to information and care, and 90 days complications were collected. The cohort included 34 females and 1 male with a mean age of 15.2 years at the time of surgery. There were 16 Lenke 1 and 19 Lenke 5 in the study. Mean preoperative major thoracic and thoracolumbar/lumbar Cobb's angle were 52˚±7.6˚ and 51˚±4.5˚ respectively. Average blood loss and surgical time were 102 ±6.4 ml and 168 ± 10.2 mins respectively. Average time to commencing solid food was 6.5±1.5 hrs. Average time to mobilization following surgery was 15.5± 4.3 hrs. The average duration to the stopping of the epidural was 42.5±3.5 hrs. The average dose of opioid consumption intraoperatively was 600.5±100.5 mcg of fentanyl i.v. and 12.5±4.5 mg morphine i.v. Postoperatively opioids were administered via an epidural catheter at a dose of 2 mg of morphine every 24 hours up to 2 days and an infusion of 2mcg/hr of fentanyl along with 0.12-0.15% ropivacaine. The average duration to transition to oral analgesia was 55.5±8.5 hrs .20 patients had urinary catheter and the average time to removal of the catheter was 17.5±1.4 hrs. 25 patients had a chest tube and the average time to remove of chest tube was 25.5±3.2 hrs. The average length of hospital stay was 3.1±0.5 days. No patient had postoperative ileus or requirement of blood transfusion or any other complications. No correlation was found between LOS and initial cobb angle. The application of ERP in AIS patients undergoing NFASC results in reduced LOS and indirectly the cost, reduced post-operative opioid use, and overall improve patient satisfaction score

Summary Statement. To evaluate carbon-fiber-reinforced PEEK as alternative biomaterial for total disc arthroplasty a closed loop between biotribology (in vitro), application of sterile particle suspensions in the epidural space of rabbits and biological response in vivo was established. Introduction. To prevent adjacent level degeneration in the cervical spine, total disc arthroplasty (TDA-C) remains an interesting surgical procedure for degenerative disc disease. Short- or midterm complications are migration, impaired post-operative neurological assessment due to artefacts in x-ray and MRI diagnosis and substantial rates of heterotopic ossification. The idea was to create a TDA-C design based on a polymer-on-polymer articulation to overcome these limitations of the clinically established metal-on-polyethylene designs. The objective of our study was to characterise the biotribological behaviour of an experimental cervical disc replacement made out of carbon-fiber-reinforced (CFR) PEEK and evaluate the biological response of particulate wear debris in the epidural space in vivo. Materials & Methods. In vitro wear simulation acc. to ISO 18192-1 was performed for 10 million cycles on a clinically established TDA-C device (Aesculap, Tuttlingen) made of cobalt-chromium-on-polyethylene in a direct comparison to an experimental disc prototype made of CFR-PEEK. An estimation of particle size and morphology was done acc. to Affatato et al. [5] and sterile suspensions of comparable particles (size 90% < 1 µm) in phospate buffered saline (PBS) were produced [6] for the application in the epidural space of 36 white new zealand rabbits. The particle concentration was 1 mg/ml with a volume of 0.2 ml injected percutaneously using fluoroscopic guidance and the inflammatory response was assessed 3 and 6 months post-operatively in a direct comparison between the groups PBS (control), UHMWPE and CFR-PEEK. Results. The gravimetric wear rate was for the cobalt-chromium-on-polyethylene TDA-C device as a clinical reference 1.0 ± 0.1 mg/ million cycles, compared to 0.02 ± 0.02 mg/ million cycles for the experimental CFR-PEEK articulation (p < 0.001), whereas the cumulative amount of wear of the CFR-PEEK TDA-C prototypes (0.5 ± 0.23 mg/ million cycles) was decreased by an order of a magnitude compared to cobalt-chromium-on-polyethylene (12.1 ± 1.46 mg/ million cycles) (p < 0.001). For CFR-PEEK and UHMWPE most of the particles were observed in a submicron size range and the morphology was comparable. Histopathological examination demonstrated wear debris in the vertebral canal of injection sites surrounded by inflammatory cells. The inflammation was limited to the epidural space around the particles and polymer particles were associated by a low grade foreign body reaction comprising macrophages and multi-nucleated giant cells. CFR-PEEK particulate wear debris showed at least similar histopathological reactions than UHMWPE in the cervical epidural space. Conclusion. A closed loop between biotribology (in vitro), application of sterile particle suspensions in the epidural space of rabbits and biological response in vivo was established to evaluate carbon-fiber-reinforced PEEK as alternative biomaterial for total disc arthroplasty

Background. Adequate pain management is mandatory for patients' early rehabilitation and improvement of outcome after total knee arthroplasty (TKA). Conventional pain management, consisted of mainly opioids, has some adverse effects such as dizziness and nausea. Motor blockade occasionally resulted from epidural analgesics. A novel multimodal analgesic strategy with peripheral nerve block, peri-articular injection (PAI) and intravenous patient controlled analgesia (IVPCA) were utilized for our patients receiving TKA. In this study, we compared the clinical efficacy and adverse effects in the group of multimodal analgesia (MA) or epidural analgesia alone. Methods. One hundred and eighteen patients undergoing TKA with spinal anesthesia were enrolled. Patients of TKA received either our protocol of multimodal analgesia or patient controlled epidural analgesia (PCEA) alone. MA included ultrasound guided nerve block in femoral and obturator nerves before spinal anesthesia, and PAI mixed with NSAID, morphine, ropivacaine and epinephrine, as well as IVPCA after surgeries. The analgesic effect with numeric rating scale (NRS) and occurrence of adverse effects, including motor blockade, numbness, postoperative nausea/vomiting (PONV), and dizziness were recorded for all patients. Results. Thirty-one patients received MA, and eighty-seven patients received PCEA. No significant difference of NRS in MA and PCEA group within 24 hours after surgery either in rest (0.2 ± 1 compared with 0.22 ± 0.98; p = 0.930) or motion (0.40 ± 1.56 compared with 0.31± 1.23; p = 0.764). MA group sustained lesser motor blockade than PCEA (6.45% compared with 22.98%; p = 0.028) beyond 24 hours after surgery. The occurrence of numbness is lower in MA group (18.52%) compared with PCEA group(43.33%) (p=0.031). No statistic difference of PONV and dizziness is noted between two groups. However, there is a trend that lesser PONV and dizziness occurred in MA group than PCEA group. Conclusion. TKA patients receiving either MA or PCEA have adequate analgesic efficacy after surgeries. MA group has a lower incidence of motor blockade and PONV than PCEA. This multimodal analgesia proposed here has shown patients' safety and improved pain control after TKA, decreased narcotics use and their associated side effects. Besides, lesser motor blockade and adequate pain relief may encourage patient's early rehabilitation

Background. Recently, some studies have focused attention on the possibility that anaerobic pathogens of low virulence could constitute an etiological factor in disc herniation. There have been isolated such strains, predominantly Propionibacterium acne, between 7 and 53% of patients undergoing surgery for disc pathology. According to these studies, patients with anaerobic infections of the disc are more likely to develop Modic changes in the adjacent vertebrae. The aim of this work was to test this hypothesis by growing in specific media the disc material extracted in a series of lumbar discectomy and relating this factor with the presence of pre-intervention Modic changes. Methods. A total of 22 consecutive patients undergoing primary unisegmental discectomy for lumbar disc herniation (77.2% male, mean age 40.1 ± 9.1 years) were included. All patients were immunocompetent and none had previously received an epidural steroid injection prior surgery. MRI study confirmed the disc herniation. Following strict antiseptic protocols, the extracted disc material was sent for slow-growth anaerobic enriched culture (>10 days). Results. In total, anaerobic cultures were positive in 7 cases (31.8%) all men. In 5 of these cases, the symptoms developed with an acute onset. The isolated germs were always unique: Propionibacterium acne (3), Streptococcus parasanguinis (1), Actinomyces naeslundii (1), Actinomyces meyeri (1) and methicillin sensitive Staphylococcus epidermidis. Only two (28.6%) of these 7 patients had Modic changes on MRI prior surgery (one type I, one type 2). None of the patients with negative cultures had Modic changes. Conclusions. These findings support the theory that anaerobic infections of low virulence and slow growth may contribute to the pathogenesis of herniated discs. However, these cases do not necessarily develop type 1 Modic changes as previously speculated. Level of evidence. Level IV

Local infiltration analgesia is a relatively novel technique developed for effective pain control following total knee replacement, reducing requirements of epidural or parenteral post-operative analgesia. The study aimed to investigate the anatomical spread of Local Infiltration Analgesia (LIA) used intra-operatively in total knee arthroplasty (TKA) and identify the nerve structures reached by the injected fluid. Six fresh-frozen cadaveric lower limbs were injected with 180ml of a solution of latex and India ink to enable visualisation. Injections were done according to our standardised LIA technique. Wounds were closed and limbs were placed flat in a freezer at −20°C for two weeks. Limbs were then either sliced or dissected to identify solution locations. Injected solution was found from the proximal thigh to the middle of the lower leg. The main areas of concentration were the popliteal fossa, the anterior aspect of the femur and the subcutaneous tissue of the anterior aspect of the knee. There was less solution in the lower popliteal fossa. The solution was found to reach the majority of the terminal branches of the tibial, fibular and obturator nerves. Overall, there was good infiltration of nerves supplying the knee. The lack of infiltration into the lower popliteal fossa suggests more fluid or a different injection point could be used. The solution that travelled distally to the extensor muscles of the lower leg probably has no beneficial analgesic effect for a TKA patient. This LIA technique reached most nerves that innervate the knee joint which supports the positive clinical results from this LIA technique. However, there may be scope to optimise the injection sites

Background and Aims. Transforaminal epidurals (TFEs) have been widely used as a treatment for lumbar radicular pain since its introduction by Krempen and Smith in 1974. 1. Originally used as a diagnostic tool, it is now becoming increasingly recognised as a definitive treatment. 2. This study investigates the use of TFEs by a single surgeon over 4 years. We hoped that the study would add to our understanding and the discussion of the actual benefit of therapeutic steroid and local anaesthetic injections by this route. 3. . Methods and Results. A total of 181 patients were identified. At injection 10mls 0.25% Marcaine and 40mg Depomedrone was injected under fluoroscopic guidance. Clinic notes and MRI reports for all patients were reviewed. Of the 176 patients included in the study, 127 showed a symptomatic improvement. Of these patients, 59 proceeded to surgical decompression. For 50 patients, TFE was the definitive treatment. 13 patients were offered but declined surgery. 5 patients were too frail to proceed to surgery. 49 patients showed no symptomatic improvement. Of this group, 34 were deemed unsuitable for surgical intervention. 15 patients did proceed to surgery. Conclusions and Discussion. These results are comparable to other similar case series. Vad et al. 3. demonstrated that 78% of patients studied were satisfied with the outcome of TFE. Riew et al. 2. showed that 53% of their study group avoided surgery due to positive long term effect of TFE. The operative notes of the 15 patients who proceeded to surgery despite a negative TFE outcome are being reviewed and will be presented. Conflicts of Interest. None. Source of Funding. None

Summary Statement. The spinal cord showed marked sensibility to acute compression causing complete and irreversible injury. On the contrary, the spinal cord has more ability for adaptation to slow progressive compression mechanisms having the possibility of neural recovery after compression release. Introduction. The aim of this experimental study was to establish, by means of neurophysiologic monitoring, the degree of compression needed to cause neurologic injury to the spinal cord, and analyze whether these limits are different making fast or slow compression. Material and Methods. Spinal cord was exposed from T7 to T11 in 5 domestic pigs with a mean weight of 35 kg. The T8 and T9 spinal roots were also exposed. A pair of sticks, attached to a precise compression device, was set up to both sides of the spinal cord between T8 and T9 roots. Sequentially, the sticks were approximated 0.5 mm every 2 minutes causing progressive spinal cord compression. An acute compression of the spinal cord was also reproduced by a 2.5 mm displacement of the sticks. Cord to cord motor evoked potentials were obtained with two epidural catheters, stimulating proximal to T6 and recording below the compression level, distal to T10, for each sequential approach of the sticks. Results. The mean width of the dural sac was 7.1 mm. For progressive compression, increasing latency and decreasing amplitude of the evoked potentials were observed after a mean displacement of the sticks of 3.2 ± 0.9 mm, the evoked potential finally disappearing after a mean displacement of 4.6 ± 1.2 mm. The potential returned 16.8 ± 3.2 minutes after the compression was stopped in every case. The evoked potentials immediately disappeared after an acute compression 2.5 ± 0.3 mm, without any sign of recovering after 30 minutes. Conclusion. The proposed experimental model replicates the mechanism of a spinal cord injury caused by medially displaced screws into the spinal canal, causing therefore lateral compression to the spinal cord. The spinal cord showed marked sensibility to acute compression, which caused complete and irreversible injury. On the contrary, the spinal cord has more ability for adaptation to progressive and slow compression mechanisms. From a clinical point of view, it seems mandatory to avoid maneuvers of rapid mobilization or acute, even minimal, contusions of the thoracic cord

Summary Statement. Novel radiopaque UHMWPE sublaminar cables may be a promising alternative to gliding pedicle screws or titanium sublaminar cables within a growth-guidance system for the surgical treatment of early onset scoliosis. Introduction. Growth-guidance or self-lengthening rod systems are an alternative to subcutaneous growing rods and the vertical expandable prosthetic titanium rib for the treatment of early onset scoliosis. Their main perceived advantage over growing rods is the marked decrease in subsequent operative procedures. The Shilla growth-guidance system and a modern Luque trolley are examples of such systems; both depend on gliding pedicle screws and/or sliding titanium sublaminar wires. However, the unknown consequences of metal-on-metal wear debris are reason for concern especially in young patients. In this study, instrumentation stability, residual growth in the operated segment after surgery and biocompatibility of the novel radiopaque UHMWPE cables as an alternative to gliding pedicles screws or titanium sublaminar wires were assessed in an immature sheep model. Materials and methods. Twelve immature sheep were treated with segmental sublaminar spinal instrumentation: dual CoCr rods were held in place by pedicle screws at the most caudal instrumented level (L5) and novel radiopaque UHMWPE (Bi. 2. O. 3. additive) woven cables were placed at 5 thoracolumbar levels. Lateral radiographs were taken at 4-week intervals to evaluate growth of the instrumented segment. Four age-matched, unoperated animals served as radiographic control. After 24 weeks follow-up, the animals were sacrificed and the spines were harvested for histological evaluation and CT analysis. Results. No neurological deficits and no complications occurred during the initial postoperative period. One animal died during follow-up due to unknown cause. At sacrifice, none of the cables had loosened and the instrumentation remained stable. Substantial growth occurred in the instrumented segment (L5-T13) in the intervention group. No significant difference in growth of the operated segment was found between the intervention and control groups. Histological analysis showed fibrous encapsulation of the novel radiopaque UHMWPE sublaminar cable in the epidural space, with no evidence of chronic inflammation. Discussion. Novel radiopaque UHMWPE cables may be a promising alternative to gliding pedicle screws or titanium sublaminar cables within a growth-guidance system. UHMWPE cables may improve growth results due to the smooth surface properties of the UHMWPE cable and address concerns regarding the consequences of metal-on-metal wear debris

Patients undergoing total knee arthroplasty (TKA) experience significant post-operative pain. We report the results of a new comprehensive patient care plan to manage peri-operative pain, enable early mobilisation and reduce length of hospital stay in TKA. A prospective audit of 1081 patients undergoing primary TKA during 2008 and 2009 was completed. All patients followed a planned programme including pre-operative patient education, pre-emptive analgesia, spinal/epidural anaesthesia with propofol sedation, intra-articular soft tissue wound infiltration, post-operative high volume intermittent ropivacaine boluses with an intra-articular catheter and early mobilisation. The primary outcome measure was the day of discharge from hospital. Secondary outcomes were verbal rating pain scores on movement, time to first mobilisation, nausea and vomiting scores, urinary catheterisation for retention, need for rescue analgesia, maximum flexion at discharge and six weeks post-operatively, and Oxford score improvement. The median day of discharge to home was post-operative day four. Median pain score on mobilisation was three for first post-operative night, day one and day two. 35% of patients ambulated on the day of surgery and 95% of patients within 24 hours. 79% patients experienced no nausea or vomiting. Catheterisation rate was 6.9%. Rescue analgesia was required in 5% of cases. Median maximum flexion was 85° on discharge and 93° at six weeks post-operatively. Only 6.6% of patients had a reduction in maximum flexion (loss of more than 5°) at six weeks. Median Oxford score had improved from 42 pre-operatively to 27 at six weeks post-operatively. The infection rate was 0.7% and the DVT and PTE rates were 0.6% and 0.5% respectively. This multidisciplinary approach provides satisfactory post-operative analgesia allowing early safe ambulation and discharge from hospital. Anticipated problems did not arise, with early discharge not being detrimental to flexion achieved at six weeks and infection rates not increasing with the use of intra-articular catheters

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When transferring tissue regenerative strategies involving skeletal stem cells to human application, consideration needs to be given to factors that may affect the function of the cells that are transferred. Local anaesthetics are frequently used during surgical procedures, either administered directly into the operative site or infiltrated subcutaneously around the wound. The aim of this study was to investigate the effects of commonly used local anaesthetics on the morphology, function and survival of human adult skeletal stem cells.

Cells from three patients who were undergoing elective hip replacement were harvested and incubated for two hours with 1% lidocaine, 0.5% levobupivacaine or 0.5% bupivacaine hydrochloride solutions. Viability was quantified using WST-1 and DNA assays. Viability and morphology were further characterised using CellTracker Green/Ethidium Homodimer-1 immunocytochemistry and function was assessed by an alkaline phosphatase assay. An additional group was cultured for a further seven days to allow potential recovery of the cells after removal of the local anaesthetic.

A statistically significant and dose dependent reduction in cell viability and number was observed in the cell cultures exposed to all three local anaesthetics at concentrations of 25% and 50%, and this was maintained even following culture for a further seven days.

This study indicates that certain local anaesthetic agents in widespread clinical use are deleterious to skeletal progenitor cells when studied in vitro; this might have relevance in clinical applications.

A rat model of lumbar root constriction with an additional sympathectomy in some animals was used to assess whether the sympathetic nerves influenced radicular pain. Behavioural tests were undertaken before and after the operation.

On the 28th post-operative day, both dorsal root ganglia and the spinal roots of L4 and L5 were removed, frozen and sectioned on a cryostat (8 μm to 10 μm). Immunostaining was then performed with antibodies to tyrosine hydroxylase (TH) according to the Avidin Biotin Complex method. In order to quantify the presence of sympathetic nerve fibres, we counted TH-immunoreactive fibres in the dorsal root ganglia using a light microscope equipped with a micrometer graticule (10 x 10 squares, 500 mm x 500 mm). We counted the squares of the graticule which contained TH-immunoreactive fibres for each of five randomly-selected sections of the dorsal root ganglia.

The root constriction group showed mechanical allodynia and thermal hyperalgesia. In this group, TH-immunoreactive fibres were abundant in the ipsilateral dorsal root ganglia at L5 and L4 compared with the opposite side. In the sympathectomy group, mechanical hypersensitivity was attenuated significantly.

We consider that the sympathetic nervous system plays an important role in the generation of radicular pain.

Gene therapy with insulin-like growth factor-1 (IGF-1) increases matrix production and enhances chondrocyte proliferation and survival in vitro. The purpose of this study was to determine whether arthroscopically-grafted chondrocytes genetically modified by an adenovirus vector encoding equine IGF-1 (AdIGF-1) would have a beneficial effect on cartilage healing in an equine femoropatellar joint model.

A total of 16 horses underwent arthroscopic repair of a single 15 mm cartilage defect in each femoropatellar joint. One joint received 2 × 10⁷ AdIGF-1 modified chondrocytes and the contralateral joint received 2 × 10⁷ naive (unmodified) chondrocytes. Repairs were analysed at four weeks, nine weeks and eight months after surgery. Morphological and histological appearance, IGF-1 and collagen type II gene expression (polymerase chain reaction, in situ hybridisation and immunohistochemistry), collagen type II content (cyanogen bromide and sodium dodecyl sulphate-polyacrylamide gel electrophoresis), proteoglycan content (dimethylmethylene blue assay), and gene expression for collagen type I, matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, aggrecanase-1, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-3 were evaluated.

Genetic modification of chondrocytes significantly increased IGF-1 mRNA and ligand production in repair tissue for up to nine weeks following transplantation. The gross and histological appearance of IGF-1 modified repair tissue was improved over control defects. Gross filling of defects was significantly improved at four weeks, and a more hyaline-like tissue covered the lesions at eight months. Histological outcome at four and nine weeks post-transplantation revealed greater tissue filling of defects transplanted with genetically modified chondrocytes, whereas repair tissue in control defects was thin and irregular and more fibrous. Collagen type II expression in IGF-1 gene-transduced defects was increased 100-fold at four weeks and correlated with increased collagen type II immunoreaction up to eight months.

Genetic modification of chondrocytes with AdIGF-1 prior to transplantation improved early (four to nine weeks), and to a lesser degree long-term, cartilage healing in the equine model.

The equine model of cartilage healing closely resembles human clinical cartilage repair. The results of this study suggest that cartilage healing can be enhanced through genetic modification of chondrocytes prior to transplantation.