Knee Arthroplasty (knee + arthroplasty)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Knee Arthroplasty

  • total knee arthroplasty


  • Selected Abstracts


    Kinematic analysis of kneeling in cruciate-retaining and posterior-stabilized total knee arthroplasties

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2008
    Satoshi Hamai
    Abstract Kneeling is an important function of the knee for many activities of daily living. In this study, we evaluated the in vivo kinematics of kneeling after total knee arthroplasty (TKA) using radiographic based image-matching techniques. Kneeling from 90 to 120° of knee flexion produced a posterior femoral rollback after both cruciate-retaining and posterior-stabilized TKA. It could be assumed that the posterior cruciate ligament and the post-cam mechanism were functioning. The posterior-stabilized TKA design had contact regions located far posterior on the tibial insert in comparison to the cruciate-retaining TKA. Specifically, the lateral femoral condyle in posterior-stabilized TKA translated to the posterior edge of the tibial surface, although there was no finding of subluxation. After posterior-stabilized TKA, the contact position of the post-cam translated to the posterior medial corner of the post with external rotation of the femoral component. Because edge loading can induce accelerated polyethylene wear, the configuration of the post-cam mechanism should be designed to provide a larger contact area when the femoral component rotates. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:435,442, 2008 [source]


    Interface membrane fibroblasts around aseptically loosened endoprostheses express MMP-13

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2008
    Susanne Wagner
    Abstract The objective of this article was to assess whether matrix metalloproteinase-13 (MMP-13) is produced by cells of the peri-implant interface tissues and to further characterize these cells. Tissue specimens were collected from the bone,prosthesis interface at the time of revision surgery of clinically loosened hip and knee arthroplasties (n,=,27). Synovial tissues from osteoarthritic patients and young patients with mild joint deformity were used as controls (n,=,6). Tissue samples were fixed in 4% PFA, decalcified with EDTA, and embedded in paraffin. Sections (4 µm) were stained with hematoxylin/eosin and for the osteoclastic marker enzyme tartrate resistant acid phosphatase. Monocytes/macrophages were characterized with a monoclonal antibody against CD68 and mRNAs encoding MMP-13 and ,1 collagen I (COL1A1) were detected by in situ hybridization. Cells expressing transcripts encoding MMP-13 were found in 70% of the interface tissues. These cells colocalized with a cell population expressing COL1A1 mRNA, and were fibroblastic in appearance. MMP-13 expressing cells were found in the close vicinity of osteoclasts and multinuclear giant cells. No signals for transcripts encoding MMP-13 were detected in multinuclear giant cells or in osteoclasts. Control tissues were negative for transcripts encoding MMP-13 mRNA. Fibroblasts of the interface from aseptically loosened endoprostheses selectively express MMP-13. By the expression and the release of MMP-13, these fibroblastic cells may contribute to the local degradation of the extracellular matrix and to bone resorption. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:143,152, 2008 [source]


    Trends of spinal fusion surgery in Australia: 1997 to 2006

    ANZ JOURNAL OF SURGERY, Issue 11 2009
    Ian Andrew Harris
    Abstract Background:, This study aims to explore the trend in spine fusion surgery in Australia over the past 10 years, and to explore the possible influence of health insurance status (private versus public) on the rate of surgery. Methods:, Data pertaining to the rate of lumbar spine fusion from 1997 to 2006 were collected from Inpatient Statistics Collection of NSW Health, Medicare Australia Statistics and the Australian Bureau of Statistics. Data on total hip and total knee arthroplasties were collected to provide a comparator. Results:, The number of publicly performed spinal fusion procedures increased by 2% from 1997 to 2006. In comparison, privately performed spinal fusion procedures increased by 167% over the same 10-year period. In 2006, spine fusion surgery was 10.8 times more likely to be done in the private sector than in the public sector, compared with corresponding figures of 4.2 times and 3.0 times for knee replacement and hip replacement, respectively. Waiting list data showed no increase in demand for spine fusion surgery in the public sector. Conclusion:, There is a disproportionately high rate of lumbar spine fusion surgery performed in the private sector, given the rate of private insurance. The rate of increase was found to be higher than that for hip or knee arthroplasty procedures. Possible explanations for this difference include: over-servicing in the private sector, under-servicing in the public sector, differences in medical referral patterns, surgeon and patient preferences and financial incentives. [source]


    The role of selective angiographic embolization of the musculo-skeletal system in haemophilia

    HAEMOPHILIA, Issue 4 2009
    E. C. RODRIGUEZ-MERCHAN
    Summary., The incidence of haemarthrosis as a result of a spontaneous periarticular aneurysm in haemophilia is very low. In these circumstances, angiographic embolization might be considered as a promising therapeutic and coagulation factor saving option in joint bleeds not responding to replacement of coagulation factor to normal levels. Moreover, embolization should be considered as a possible treatment for postoperative pseudoaneurysms complicating total knee arthroplasty in haemophilia. However, the pathological process of aneurysmal bleeding and clotting factor replacement is entirely different. While embolization is the treatment of choice for some periarticular complications that may occur, it is by no means a panacea for all resistant periarticular bleeds in haemophilia or for postoperative bleeding which usually settles with clotting factor replacement. Another use of arterial embolization is for the treatment of haemophilic tumours of the pelvis, because they can act as a focus for infection and cause cutaneous fistulas. When they present perforations and infections of endogenous origin, their course is usually fatal. Suitable treatment has been investigated on numerous occasions, most of the literature agreeing that the only curative treatment is surgical resection. However, surgical resection after performing arterial embolization to reduce the vascularization of the pseudotumour is a good alternative, thereby reducing the size of the pseudotumour and the risk of bleeding complications during surgery. It is important to bear in mind that despite its efficacy, arterial embolization is an invasive procedure with a reported rate of complications up to 25% (16% minor, 7% serious, 2% death). [source]


    Total joint arthroplasty in haemophilia

    HAEMOPHILIA, Issue 5 2000
    Beeton
    In severely affected haemophilic patients arthropathy is a common problem which can lead to considerable pain and functional deficit. Surgical management, including total joint arthroplasty, can be undertaken if conservative management fails. A search of the literature showed that a number of studies describing the use of total knee arthroplasty (TKA) and total hip arthroplasty (THA) in haemophilia have been published, whereas shoulder, elbow and ankle arthroplasties are confined to case reports. This paper reviews the functional outcome of arthroplasty in the different joints, the postoperative and long-term complications, and the impact of HIV. Although complications are commonly described and the surgery is technically demanding, the results suggest that arthroplasty, particularly of the hip and knee, can be a valuable option in the management of severe haemophilic arthropathy. [source]


    Analgesic efficacy of subcutaneous local anaesthetic wound infiltration in bilateral knee arthroplasty: a randomised, placebo-controlled, double-blind trial

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2010
    L. Ø. ANDERSEN
    Background: High-volume wound local infiltration analgesia is effective in knee arthroplasty, but the analgesic efficacy of subcutaneous wound infiltration has not been evaluated. Methods: In a randomised, double-blind, placebo-controlled trial in 16 patients undergoing bilateral knee arthroplasty with high-volume local infiltration analgesia in the deeper layers, saline or ropivacaine 2 mg/ml was infiltrated into the subcutaneous part of the wound in each knee along with the placement of multi-fenestrated catheters in the subcutaneous wound layers in both knees. Pain was assessed for 6 h post-operatively and for 3 h after a bolus injection given through the catheter 24 h post-operatively. Results: Visual analogue scale (VAS) pain scores were significantly lower from the knee infiltrated with ropivacaine compared with the knee infiltrated with saline in the subcutaneous layer of the wound, at rest (P<0.02), with flexion of the knee (P<0.04) and when the leg was straight and elevated (P<0.04). Twenty-four hours post-operatively, a decline in the VAS pain scores was observed in both groups, with no statistically significant difference between injection of ropivacaine or saline in the subcutaneously placed catheters (P>0.05). Conclusion: As part of a total wound infiltration analgesia intraoperative subcutaneous infiltration with ropivacaine in bilateral total knee arthroplasty is effective in early post-operative pain management, while a post-operative subcutaneous bolus administration through a multiholed catheter 24 h post-operatively did not show improved analgesia compared with the administration of saline. [source]


    Continuous femoral nerve block after total knee arthroplasty?

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2009
    L. KADIC
    Background: A continuous femoral nerve block is frequently used as an adjunct therapy after total knee arthroplasty (TKA). However, there is still debate on its benefits. Methods: In this prospective, randomized study, patients received a basic analgesic regimen of paracetamol and dicloflenac for the first 48 h postoperatively. In addition, the study group received a continuous femoral nerve block. A morphine patient-controlled analgesia pump was also available as a rescue analgesic to all the patients. Patients' numeric rating scores for pain, the amount of morphine consumed and its side effects during the first 48 h were recorded. Knee flexion angles achieved during the first week were registered. Three months postoperatively, patients completed Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score. Results: The study group (n=27) had less pain (P=0.0016) during the first 48 h, was more satisfied with the analgesia (P<0.001) and used less morphine (P=0.007) compared with the control group (n=26). Fewer patients were nauseated, vomited or were drowsy in the study group (P=0.001). Also, the study group achieved better knee flexion in the first 6 days after surgery (P=0.001), with more patients reaching 90° flexion than the control group. However, after 3 months, there were no significant functional differences between the groups. Conclusion: A continuous femoral nerve block leads to better analgesia, less morphine consumption and less morphine-related side effects after TKA. Early functional recovery is improved, resulting in more patients reaching 90° knee flexion after 6 days. However, after 3 months, no significant functional benefits were found. [source]


    Post-operative anxiety and depression levels in orthopaedic surgery: a study of 56 patients undergoing hip or knee arthroplasty

    JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2009
    Richard S. J. Nickinson
    Abstract Objective, To investigate the presence and rates of anxiety and depression in postsurgical patients. Methods, The Hospital Anxiety and Depression Scale was used to measure anxiety and depression levels. Patients completed the questionnaire on the day prior to surgery, then on each post-operative day up to and including their day of discharge. Statistical analysis using logistic regression was performed to determine whether any variables were risk factors for developing anxiety or depression. Fifty-six patients undergoing lower limb arthroplasty agreed to take part. Results, Post-operatively 17 patients became anxious prior to discharge. No variables were significant predictors of anxiety. Post-operatively 28 subjects (50%) became depressed at some point prior to discharge. Females were more likely to become depressed than males odds ratio (OR) = 3.48 [95% confidence interval (CI) 1.01,11.88]. Those who had had a previous lower limb arthroplasty were more likely to develop post-operative depression, OR = 3.92 (95% CI 1.05,14.6). Site of operation was not found to be significant, OR = 0.67 (95% CI 0.20,2.22). Age and anaesthetic method were not predictive of depression. The mean time point for development of depression was 2.43 days (SD = 1.40 days) and the time of deepest depression was 2.93 days (SD = 1.72 days). The mean length of depression was 1.93 days (SD = 1.21 days). The mean length of stay for depressed patients was 5 days (SD = 1.72), compared with 4 days for the non-depressed patients (SD = 1.62 days). Conclusion, The results suggest that post-operative depression does occur in orthopaedic surgery. The prevalence may be higher than that reported in other surgical specialities. These findings emphasize the need for evaluation of patients' psychiatric state post-operatively. [source]


    Precise landmarking in computer assisted total knee arthroplasty is critical to final alignment

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2010
    Yaron S. Brin
    Abstract Image-free computer navigation systems build a frame of reference of a patient's knee from anatomical landmarks entered by the surgeon during the initial stage of total knee arthroplasty. We performed tibial cuts on 70 sawbones using computer navigation. All landmarks were marked identically except for the tibial mechanical entry point, which was marked correctly in 10 bones and with offsets of 5, 10, and 15,mm medially and laterally in the others. The actual coronal angle of the tibial cuts was measured directly and compared to the final angle given by the navigation system. Significant deviations of the coronal angle were observed in the trial groups. Landmarking errors during navigated TKA can lead to inaccurate tibial bone cuts. This navigation system did not have an iterative software method to verify landmarking errors that can lead to inaccurate tibia bone cuts. Published by Wiley Periodicals, Inc. J Orthop Res 28:1355,1359, 2010 [source]


    Joint line elevation in revision TKA leads to increased patellofemoral contact forces

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2010
    Christian König
    Abstract One difficulty in revision total knee arthroplasty (TKA) is the management of distal femoral bone defects in which a joint line elevation (JLE) is likely to occur. Although JLE has been associated with inferior clinical results, the effect that an elevated joint line has on knee contact forces has not been investigated. To understand the clinical observations and elaborate the potential risk associated with a JLE, we performed a virtual TKA on the musculoskeletal models of four subjects. Tibio- and patellofemoral joint contact forces (JCF) were calculated for walking and stair climbing, varying the location of the joint line. An elevation of the joint line primarily affected the patellofemoral joint with JCF increases of as much as 60% of the patient's body weight (BW) at 10-mm JLE and 90% BW at 15-mm JLE, while the largest increase in tibiofemoral JCF was only 14% BW. This data demonstrates the importance of restoring the joint line, as it plays a critical role for the magnitudes of the JCFs, particularly for the patellofemoral joint. JLE caused by managing distal femoral defects with downsizing and proximalizing the femoral component could increase the patellofemoral contact forces, and may be a contributing factor to postoperative complications such as pain, polyethylene wear, and limited function. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1,5, 2010 [source]


    Three-dimensional knee joint kinematics during golf swing and stationary cycling after total knee arthroplasty

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2008
    Satoshi Hamai
    Abstract The expectation of returning to sports activities after total knee arthroplasty (TKA) has become more important to patients than ever. To our knowledge, no studies have been published evaluating the three-dimensional knee joint kinematics during sports activity after TKA. Continuous X-ray images of the golf swing and stationary cycling were taken using a large flat panel detector for four and eight post-arthroplasty knees, respectively. The implant flexion and axial rotation angles were determined using a radiographic-based, image-matching technique. Both the golf swing from the set-up position to the top of the backswing, and the stationary cycling from the top position of the crank to the bottom position of the crank, produced progressive axial rotational motions (p,=,0.73). However, the golf swing from the top of the backswing to the end of the follow-through produced significantly larger magnitudes of rotational motions in comparison to stationary cycling (p,<,0.01). Excessive internal,external rotations generated from the top of the backswing to the end of the follow-through could contribute to accelerated polyethylene wear. However, gradual rotational movements were consistently demonstrated during the stationary cycling. Therefore, stationary cycling is recommended rather than playing golf for patients following a TKA who wish to remain physically active. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]


    Kinematic analysis of kneeling in cruciate-retaining and posterior-stabilized total knee arthroplasties

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2008
    Satoshi Hamai
    Abstract Kneeling is an important function of the knee for many activities of daily living. In this study, we evaluated the in vivo kinematics of kneeling after total knee arthroplasty (TKA) using radiographic based image-matching techniques. Kneeling from 90 to 120° of knee flexion produced a posterior femoral rollback after both cruciate-retaining and posterior-stabilized TKA. It could be assumed that the posterior cruciate ligament and the post-cam mechanism were functioning. The posterior-stabilized TKA design had contact regions located far posterior on the tibial insert in comparison to the cruciate-retaining TKA. Specifically, the lateral femoral condyle in posterior-stabilized TKA translated to the posterior edge of the tibial surface, although there was no finding of subluxation. After posterior-stabilized TKA, the contact position of the post-cam translated to the posterior medial corner of the post with external rotation of the femoral component. Because edge loading can induce accelerated polyethylene wear, the configuration of the post-cam mechanism should be designed to provide a larger contact area when the femoral component rotates. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:435,442, 2008 [source]


    Patellar blood flow during knee arthroplasty surgical exposure: Intraoperative monitoring by laser doppler flowmetry

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2007
    Axel Hempfing
    Abstract Patellofemoral complications following knee arthroplasty are a well-known problem. Patellar ischemia has been suspected to be causative for fracture, anterior knee pain, and patella component failure. The purpose of this study was to assess the influence of knee arthroplasty surgical dissection on patellar blood flow. Patellar blood flow was measured by means of intraosseous laser Doppler flowmetry (LDF) in 10 patients undergoing total knee arthroplasty by a standard medial parapatellar approach. The initial blood flow was 121.6,±,114.7 AU. The signal significantly decreased by 71% (p,=,0.0051) when the knee was flexed and lost the pulsatile signal pattern in 80%. After arthrotomy, the signal was 100.1,±,120.3 AU in extension. The lowest signal was found in flexion and eversion of the patella (mean, 18,±,10.7 AU) and all signals lost pulsatility. As compared to the initial values, completion of the soft tissue dissection did not lead to a significant change of the blood flow signal (121.3,±,104.8; p,=,0.6835). Flexion of the knee joint markedly reduced patellar perfusion. Standard medial parapatellar approach did not significantly change patellar blood flow. This study does not support the theory of postoperative patellar ischemia as a cause of anterior knee pain or patellofemoral problems. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1389,1394, 2007 [source]


    Safety of, and biological and functional response to, a novel metallic implant for the management of focal full-thickness cartilage defects: Preliminary assessment in an animal model out to 1 year

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006
    Carl A. Kirker-Head
    Abstract Focal full-thickness cartilage lesions of the human medial femoral condyle (MFC) can cause pain and functional impairment. Affected middle-aged patients respond unpredictably to existing treatments and knee arthroplasty may be required, prompting risk of revision. This study assesses the safety of, and biological and functional response to, a metallic resurfacing implant which may delay or obviate the need for traditional arthroplasty. The anatomic contour of the surgically exposed MFC of six adult goats was digitally mapped and an 11 mm diameter full-thickness osteochondral defect was created. An anchor-based Co,Cr resurfacing implant, matching the mapped articular contour, was implanted. Each goat's contralateral unoperated femorotibial joint was used as a control. Postoperative outcome was assessed by lameness examination, radiography, arthroscopy, synoviocentesis, necropsy, and histology up to 26 (n,=,3) or 52 (n,=,3) weeks. By postoperative week (POW) 4, goats demonstrated normal range of motion, no joint effusion, and only mild lameness in the operated limb. By POW 26 the animals were sound with only occasional very mild lameness. Arthroscopy at POW 14 revealed moderate synovial inflammation and a chondral membrane extending centrally across the implant surface. Radiographs at POWs 14 to 52 implied implant stability in the operated joints, as well as subchondral bone remodeling and mild exostosis formation in the operated and contralateral unoperated joints of some goats. By POW 26, histology revealed new trabecular bone abutting the implant. At POWs 26 and 52 MFC cartilage was metachromatic and intact in the operated and unoperated femorotibial joints. Proximal tibiae of some operated and unoperated limbs demonstrated limited subchondral bone remodeling and foci of articular cartilage fibrillation and thinning. The chondral membrane crossing the prosthesis possessed a metachromatic matrix containing singular and clustered chondrocytes. Our data imply the safety, biocompatibility, and functionality of the implant. Focal articular damage was documented in the operated joints at POWs 26 and 52, but lesions were much reduced over those previously reported in untreated defects. Expanded animal or preclinical human studies are justified. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]


    Knee biomechanics after UKA and its relation to the ACL,a robotic investigation

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2006
    Jeremy F. Suggs
    Abstract Unicompartmental knee arthroplasty (UKA) has regained popularity in recent years. However, limited data exist on how UKA affects knee biomechanics. The role of the anterior cruciate ligament (ACL) after fixed bearing UKA remains controversial. In this study, a robotic testing system was used to apply a quadriceps/hamstrings load to cadaveric knee specimens in the intact state, after medial UKA, and after transection of the ACL in UKA. The load was applied to the knee from full extension to 120° of flexion in 30° increments. UKA generally did not affect anterior,posterior (AP) femoral position, but did cause external tibial rotation and variations in varus,valgus rotation compared to the intact knee. ACL transection after UKA shifted the femur posteriorly compared to the intact and UKA knees and increased internal tibial rotation compared to the UKA knee at low flexion. The AP motion of the articular contact position in the implant was increased after ACL transection. These data might help explain the mechanism of tibial component loosening and provide insight into further investigations of polyethylene wear in UKA. Based on the kinematic data, the ACL should be functional to provide patients the greatest opportunity for long-term success after medial UKA. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]


    Altered loading during walking and sit-to-stand is affected by quadriceps weakness after total knee arthroplasty

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2005
    Ryan L. Mizner
    Abstract Purpose: Total knee arthroplasty (TKA) successfully reduces pain, but has not achieved comparable improvements in function. We hypothesized that quadriceps strength affects performance by altering loading and movement patterns during functional tasks. Methods: Fourteen subjects with isolated, unilateral TKA were tested three months after surgery. Quadriceps strength was assessed isometrically and kinematics, kinetics, and EMG were collected during level walking and sit-to-stand (STS). Function was assessed using the timed up and go test (TUG), stair climbing test (SCT), and the 6 min walk test (6MW). Results: Functional performance was significantly related to the quadriceps strength of both legs, but was more strongly related to the uninvolved strength (involved rho = ,0.43 with TUG; ,0.65 with SCT; 0.64 with 6MW) (uninvolved rho = ,0.63 with TUG; ,0.68 with SCT; 0.77 with 6MW). During STS, subjects shifted weight away from the operated limb (p <0.01). Quadriceps muscle activity and the extension moments at the knee and hip were smaller in the involved compared to the uninvolved (p <0.05). The amount of asymmetry in knee excursion during weight acceptance in gait, the asymmetry in weight bearing from sit-to-stand, and the uninvolved hip extension moment during STS were related to the amount of asymmetry in quadriceps strength (rho > 0.56, p < 0.05). Conclusions: Quadriceps weakness in patients with TKA has a substantial impact on the movement patterns and performance of the knee during functionally important tasks. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]


    Circulating and synovial levels of IGF-I, cytokines, physical function and anthropometry differ in women awaiting total knee arthroplasty when compared to men

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2005
    Sonia M. C. Pagura
    Abstract Purpose: Determine if gender differences in osteoarthritis relate to cytokine and growth factor levels. Methods: Cross-sectional comparison of serum and synovial concentrations of cytokines (IL-1,,, TNF-,, IL-6), growth factors (IGF-I, TGF-,, IRAP), physical performance and perceived function in total knee arthroplasty candidates (TKAC) (n = 17) and healthy controls (n = 21) was done. Results: Serum IGF-I values were reduced in female (TKAC 137.6 ± 7.2; Controls 160.2 ± 26.2) but not male TKAC (TKAC 182.6 ± 18.4; Controls 184.0 ± 18.4) (p < 0.05). Serum and synovial levels of cytokines and growth factors did not differ significantly by group or gender. Physical performance testing (SPW, TUG) revealed significant group and gender differences (p = 0.001) with women demonstrating greater functional impairment. Discussion: A systemic, not local component to OA pathophysiology may exist for female TKAC. Male TKAC were less impaired, and their IGF-I levels differ little from Control values. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]


    Spatially-localized correlation of dGEMRIC-measured GAG distribution and mechanical stiffness in the human tibial plateau

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2005
    Joseph T. Samosky
    Abstract The concentration of glycosaminoglycan (GAG) in articular cartilage is known to be an important determinant of tissue mechanical properties based on numerous studies relating bulk GAG and mechanical properties. To date limited information exists regarding the relationship between GAG and mechanical properties on a spatially-localized basis in intact samples of native tissue. This relation can now be explored by using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC,a recently available non-destructive magnetic resonance imaging method for measuring glycosaminoglycan concentration) combined with non-destructive mechanical indentation testing. In this study, three tibial plateaus from patients undergoing total knee arthroplasty were imaged by dGEMRIC. At 33,44 test locations for each tibial plateau, the load response to focal indentation was measured as an index of cartilage stiffness. Overall, a high correlation was found between the dGEMRIC index (T) and local stiffness (Pearson correlation coefficients r = 0.90, 0.64, 0.81; p < 0.0001) when the GAG at each test location was averaged over a depth of tissue comparable to that affected by the indentation. When GAG was averaged over larger depths, the correlations were generally lower. In addition, the correlations improved when the central and peripheral (submeniscal) areas of the tibial plateau were analyzed separately, suggesting that a factor other than GAG concentration is also contributing to indentation stiffness. The results demonstrate the importance of MRI in yielding spatial localization of GAG concentration in the evaluation of cartilage mechanical properties when heterogeneous samples are involved and suggest the possibility that the evaluation of mechanical properties may be improved further by adding other MRI parameters sensitive to the collagen component of cartilage. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]


    In vivo kinematics of total knee arthroplasty: Flat compared with concave tibial joint surface

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2000
    J. Uvehammer
    This study evaluated the influence of the geometric configuration of the tibial joint area on the kinematics of the knee. Twenty-two patients with noninflammatory arthritis and minor preoperative deformity were studied. They each received an AMK total knee replacement with retention of the posterior cruciate ligament. Eleven patients without any knee abnormalities were used as controls. The patients were stratified to either the flat (terminology of the manufacturer: standard) or concave (terminology of the manufacturer: constrained) polyethylene insert (n = 11 in each group). Knee kinematics were assessed 1 year after the operation by having the patient ascend a platform corresponding to an extension of the knee from 50 to 70° of flexion. During this motion, two film-exchangers simultaneously exposed six to 13 pairs of serial stereoradiographs. The concave geometric configuration of the tibial insert resulted paradoxically in increased anterior-posterior translations compared with the flat insect but no significant change of rotations and translations in the other directions. Compared with normal knees, the most obvious abnormality was increased anterior-posterior translations (p < 0.004). At 50° of flexion, the implants with the flat tibial polyethylene insert had displaced 2 times and the concave ones had displaced 2.5 times more posteriorly than the normal knees (p , 0.001). Less internal tibial rotation was also recorded in the flexed positions for both types of inserts compared with the normal knees (p < 0.02). Four knees in four patients, who reported symptoms of instability and abnormal knee function, showed significantly increased proximal displacement of the center of the tibial plateau in the flexed position. The findings suggest that current prosthetic designs and surgical technique do not restore normal knee kinematics and indicate that design improvements should rely on in vivo kinematic studies. [source]


    Ultrasound screening for asymptomatic deep vein thrombosis after major orthopaedic surgery: the VENUS study

    JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2007
    S. M. SCHELLONG
    Summary.,Background:,Venography is currently used to assess the incidence of deep vein thrombosis (DVT) in dose-finding and confirmatory trials of new antithrombotic agents. Centrally adjudicated, complete compression ultrasound (CCUS) could be a non-invasive alternative to venography. Objectives:,A substudy of two, similarly designed, phase IIb trials of a novel, oral anticoagulant for the prevention of venous thromboembolism after elective hip or knee arthroplasty was undertaken to validate CCUS against venography. Patients/Methods:,Patients received study drugs until mandatory, bilateral venography was performed 7 ± 2 days after surgery. CCUS was performed within 24 h after venography by sonographers blinded to the venography result. Sonographers were trained and certified for the standardized examination and documentation procedure. Venograms and sonograms were adjudicated centrally at different sites by two independent readers; discrepancies between readers were resolved by consensus. Results:,A total of 1104 matching pairs of evaluable venograms and sonograms were obtained from the participants of the two trials (n = 1435): 19% of venograms and 20% of sonograms were not evaluable. The observed frequency of any DVT was 18.9% with venography and 11.5% with CCUS. Sensitivity of CCUS compared with venography was 31.1% for any DVT (95% confidence interval 23.4, 38.9), 21.0% (2.7, 39.4) for proximal DVT, and 30.8% (23.1, 38.6) for distal DVT. The figures for specificity were 93.0% (91.0, 95.1), 98.7% (98.0, 99.5), and 93.3% (91.5, 95.3), respectively. Conclusions:,Based on these results, centrally adjudicated CCUS will be unable to replace venography for DVT screening early after major orthopaedic surgery in studies evaluating anticoagulant drugs. [source]


    The safety and outcome of joint replacement surgery in liver transplant recipients

    LIVER TRANSPLANTATION, Issue 4 2003
    Josh Levitsky
    A small group of patients may require total hip arthroplasty, total knee arthroplasty, or other joint replacement surgery after OLT for osteoporotic fractures, osteonecrosis, and osteoarthritis. Although arthroplasty is safe in the general population, its safety in liver transplant recipients is unclear. The aim of the study was to determine the safety and outcome of joint replacement surgery in our liver transplant recipients. A retrospective analysis was performed on all liver transplant recipients who had total joint arthroplasty at a single teaching institution between 1986 and 2002. Data regarding major intraoperative and postoperative complications was obtained from the medical charts and a hospital-based computer system. Of over 1,200 liver transplant recipients, we identified 7 patients who underwent 12 total arthroplasties (8 knee, 3 hip, 1 ankle). Joint replacements were performed electively for osteonecrosis (5 of 12) and osteoarthritis (5 of 12), whereas two hip arthroplasties were performed emergently for fractures. All patients with osteonecrosis or hip fracture had been treated with prolonged corticosteroids. There were no deaths or major complications in the intraoperative and postoperative periods. On long-term follow-up, no patients have had pain, dislocation, or infection in the postsurgical joint. No joint revision surgery has been required. In conclusion, a small number of stable liver transplant recipients at our institution underwent joint replacement surgery without major short-term or long-term complications. Our study suggests that joint replacement surgery may be safely and successfully performed in this population, although larger, randomized, prospective trials are needed to confirm our findings. [source]


    Feasibility of electromyography (sEMG) in measuring muscular activity during spinal anaesthesia in patients undergoing knee arthroplasty

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2005
    L. Niemi-Murola
    Background:, Bromage scale (0,3) is used to measure the degree of motor block during spinal anaesthesia. However, an estimation of motor block is difficult during surgery. The purpose of this study was to evaluate the feasibility of surface EMG describing spontaneous muscular activity in the lower extremities during spinal anaesthesia. Methods:, In part I of the study, 13 patients undergoing day case surgery were studied. They received 10 mg hyperbaric bupivacaine at interspace L3,4. EMG, sensory and muscular block were measured at 5-min intervals during the first 30 min and then every 15 min until the patient was able to flex the knee. In part II of the study, 16 patients undergoing knee arthroplasty received 10 mg bupivacaine through spinal catheter at interspace L3,4 (Group CSA). An additional bolus of 2.5 mg was administered using EMG-guidance, if needed. Another group, 15 patients, received a single bolus of bupivacaine (15,20 mg) at L3,4 (Group Bolus). EMG, muscular and sensory block were monitored as described above. The epidural catheter was used as rescue. Results:, Part I: EMG compared to modified Bromage scale showed a significant correlation (P < 0.01, Spearman rank correlation). Part II: The amount of bupivacaine was significantly reduced with EMG guidance when compared with the single bolus group (14.0 mg vs. 17.0 mg) (P < 0.05 Mann,Whitney U). Motor block started to recover before the sensory block in 7/15 CSA patients vs. 1/15 Bolus patient. Conclusion:, Stable maximal sensory block does not necessarily correlate with adequate motor block in patients receiving spinal anaesthesia induced with small bolus doses. In spite of electrical noise, EMG-guided administration of spinal anaesthesia significantly reduced the amount of bupivacaine compared to the hospital routine. Further studies are needed to develop the method. [source]


    Postoperative elevated cortisol excretion is not associated with suppression of 6-sulfatoxymelatonin excretion

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2005
    J. Derenzo
    This study tests the hypothesis that elevated postoperative excretion of cortisol is associated with suppression of the nocturnal excretion of 6-sulfatoxymelatonin, the chief metabolite of the circadian hormone, melatonin. Postoperative patients demonstrate circadian rhythm disturbances and suppression of nocturnal melatonin plasma concentration. Since the nocturnal surge in melatonin concentration in normal volunteers is time-locked to the circadian nadir of cortisol concentration, perhaps the attenuation of the nocturnal melatonin surge in postoperative patients results from prolonged elevation in the plasma cortisol concentration. In this observational study performed in 21 patients having unilateral hip or knee arthroplasty, urine was collected every 4 h for the first 48 h after surgery for measurement of urinary 6-sulfatoxymelatonin (EIA) and free cortisol (RIA) excretion. The total (P < 0.05) and peak (P < 0.02) nocturnal 6-sulfatoxymelatonin excretions were lower on the first than the second postoperative night. The nocturnal cortisol nadir preceded the 6-sulfatoxymelatonin surge in 20% of the subjects on night 1 and in 75% of the subjects on night 2. The lack of a consistent relationship between the magnitude or timing of cortisol excretion and 6-sulfatoxymelatonin excretion suggests that cortisol does not mediate postoperative 6-sulfatoxymelatonin suppression. [source]


    Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?

    PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 3 2010
    Thomas Linding Jakobsen
    Abstract Background and Purpose.,Two of the most utilized outcome measures to assess knee joint range of motion (ROM) and intra-articular effusion are goniometry and circumference, respectively. Neither goniometry nor circumference of the knee joint have been examined for both intra-tester and inter-tester in patients with total knee arthroplasty (TKA). The purpose of this study was to determine the intra-tester and inter-tester reliability of active and passive knee joint ROM and circumference in patients with TKA when administered by physiotherapists (testers) with different clinical experience.,Method.,The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were obtained using a universal goniometer and a tape measure, respectively. To establish reliability, intraclass correlation coefficients (ICC2,1) and smallest real difference (SRD) were calculated.,Results.,The knee joint ROM and circumference measurements were generally reliable (ICC > 0.8) within and between physiotherapists (except passive knee extension). Changes in knee joint ROM of more than 6.6° and 10° (except active knee flexion) and knee joint circumference of more than 1.0,cm and 1.63,cm represent a real clinical improvement (SRD) or deterioration for a single individual within and between physiotherapists, respectively. Generally, the experienced tester recorded larger knee joint ROM and lower circumference values than that of the inexperienced tester.,Conclusions.,In clinical practice, we suggest that repeated knee goniometric and circumferential measurements should be recorded by the same physiotherapist in individual patients with TKA. Tester experience appears not to influence the degree of reliability. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Computer-assisted tibia preparation for total ankle arthroplasty: a cadaveric study

    THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 4 2007
    Samuel B. Adams Jr
    Abstract Background Most surgeons performing total ankle arthroplasty (TAA) suggest that accurate tibial preparation perpendicular to the tibial shaft axis improves outcomes. Recent studies demonstrate that computerized surgical navigation significantly improves the accuracy of tibial preparation in total knee arthroplasty (TKA). Methods We performed the tibial preparation for TAA in seven matched pairs of cadaver lower extremities. One set of matched pairs was prepared using the conventional external tibial alignment guide/cutting block from the Scandanavian Total Ankle Replacement system (STAR, Waldemar Link GmbH & Co., Hamburg, Germany) under fluoroscopic guidance. The second set of matched pairs was prepared using the VectorVision® navigation system (BrainLAB, Munich, Germany), with currently available computed tomography (CT)-based TKA software. Pre-operative CT data were used to assess the tibial mechanical axis. In both groups, accuracy of the tibial plafond preparation relative to the tibial shaft axis in both the coronal and sagittal planes was determined by fluoroscopic, radiographic and CT analysis. Results Mean values of the tibial cut for the set of matched-pair tibiae prepared by the conventional surgical method ranged across the three imaging assessment techniques in the ranges 89.3,89.6° (coronal plane, anteroposterior) and 90.3,90.4° (sagittal plane, lateral). For the computer-navigated set, the values were 89.7,89.9° (coronal) and 89.1,89.4° (sagittal). Comparison between the conventional and computer-navigated tibial measurements were not different at the 95% confidence interval (CI) for CT, fluoroscopy or radiographic assessments. Conclusions Our results demonstrate that accuracy of TAA tibial preparation using computer-navigation equals that of the conventional technique performed by a foot and ankle surgeon experienced in TAA. We anticipate that this investigation will encourage the development of computer-navigation applications specific to TAA, with the potential of improving accuracy over conventional methods. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Analgesic efficacy of local anaesthetic wound administration in knee arthroplasty: volume vs concentration

    ANAESTHESIA, Issue 10 2010
    L. Ø. Andersen
    Summary Wound administration of local anaesthetic may be effective for postoperative pain management in knee arthroplasty, but the analgesic efficacy of local anaesthetic in relation to volume vs concentration has not been determined. In a double-blinded trial, 48 patients scheduled for total knee arthroplasty were randomly assigned to receive either a high volume/low concentration solution of ropivacaine (20 ml, 0.5%) or a low volume/high concentration solution of ropivacaine (10 ml, 1%), 6 and 24 h postoperatively through an intracapsular catheter. Pain was assessed for 2 h after administration. Pain was reduced in both groups with ropivacaine administration 24 h postoperatively (p < 0.02), but with no difference in analgesia between groups at all time intervals. No reduction in pain scores was observed with ropivacaine injection 6 h postoperatively. The median (IQR [range]) dose of oxycodone administered was 12.5 (10,19 [0,35]) mg in the high volume/low concentration group, and 20 mg (16,40 [0,65]) mg in the low volume/high concentration group (p = 0.005). In conclusion, intracapsular administration of local anaesthetic may have limited analgesic efficacy with no volume vs concentration relationship after total knee arthroplasty. [source]


    ORIGINAL ARTICLE: Analgesic efficacy of intracapsular and intra-articular local anaesthesia for knee arthroplasty

    ANAESTHESIA, Issue 9 2010
    L. Ø. Andersen
    Summary The optimal site for wound delivery of local anaesthetic after total knee arthroplasty is undetermined. Sixty patients having total knee arthroplasty received intra-operative infiltration analgesia with ropivacaine 0.2% and were then were randomly assigned to receive either intracapsular or intra-articular catheters with 20 ml ropivacaine 0.5% given at 6 h and again at 24 h, postoperatively. Analgesic efficacy was assessed for 3 h after each injection, using a visual analogue score, where 0 = no pain and 100 = worst pain. There was no statistically significant difference between groups. Maximum pain relief (median (IQR [range])) at rest observed in the 3 h after the 6 and 24 h postoperative injections was 17 (7,31 [0,80]) and 10 (4,27 [0,50]) p = 0.27 for 6,9 h; and 17 (7,33 [0,100]) and 13 (3,25 [0,72]) p = 0.28 for 24,27 h, for intracapsular and intra-articular, respectively. Intracapsular local anaesthetic has similar analgesic efficacy to intra-articular after total knee arthroplasty. [source]


    Subacute pain and function after fast-track hip and knee arthroplasty

    ANAESTHESIA, Issue 5 2009
    L. Ø. Andersen
    Summary In a well-defined fast-track setup for total hip and knee arthroplasty, with a multimodal analgesic regimen consisting of intra-operative local anaesthetic infiltration and oral celecoxib, gabapentin and paracetamol for 6 days postoperatively, we conducted a prospective, consecutive, observational study. The purpose was to describe the prevalence and intensity of subacute postoperative pain and opioid related side effects, use of analgesics and functional ability 1,10 and 30 days postoperatively. Fast-track total hip and knee arthroplasty with early discharge (< 3 days) resulted in acceptable levels of pain and postoperative nausea and vomiting with concomitant low use of opioids in > 95% of patients after discharge before day 10 after total hip arthroplasty. However, after total knee arthroplasty 52% patients reported moderate pain (VAS 30,59 mm), and 16% severe pain (VAS , 60 mm) when walking 1 month after surgery with a concomitant increase in the use of strong opioids. These results emphasise the need for improvement in analgesia after discharge following total knee arthroplasty, to facilitate rehabilitation. [source]


    Target driven analgesia for total knee arthroplasty

    ANAESTHESIA, Issue 3 2009
    D. H. Morfey
    No abstract is available for this article. [source]


    The need for patellar resurfacing in total knee arthroplasty: a literature review

    ANZ JOURNAL OF SURGERY, Issue 4 2010
    John D. Swan
    Abstract The controversy over whether or not to routinely resurface the patella during a total knee arthroplasty has persisted despite three decades of successful joint replacement procedures. Advocates for routine patellar resurfacing admit the occasional need for secondary patellar resurfacing and declare increased incidence of anterior knee pain in patients with non-resurfaced patellae as a cause for worry. Surgeons that leave the patella unresurfaced cite avoidance of complications that include patellar fracture, avascular necrosis, patellar tendon injury and instability. This review discusses the available literature on patellar resurfacing through an evidence-based analysis of randomized and pseudo-randomized controlled trials and published meta-analyses to date. The published literature seems to favour resurfacing the patellar routinely. Selective patellar resurfacing would be the ideal solution if sound pre-operative criteria could be established. So far, a method for accurately predicting which patients can avoid patellar resurfacing has not been found. Future research looking at patellar resurfacing should concentrate on developing criteria for selecting those patients that would benefit from patellar resurfacing and those that would do as well without resurfacing, and thus, limiting potential surgical complications. [source]