Total Hip Surgery Research Articles

Pharmacological treatment of heterotopic ossification following hip and acetabular surgery

Heterotopic ossification is a common complication following total hip arthroplasty and surgery following acetabular trauma. It is associated with pain and a decreased range of movement. Prophylaxis is achieved by either non-steroidal anti-inflammatory drug treatment or localised irradiation therapy. The objective of this study was to evaluate the evidence for pharmacological agents used for the prophylaxis of heterotopic ossification following hip and acetabular surgery. The study used a comprehensive literature search to identify all major clinical studies investigating the pharmacological agents used in the prophylaxis of heterotopic ossification following hip and acetabular surgery. It was concluded that indometacin remains the ‘gold standard’ for heterotopic ossification prophylaxis following total hip arthroplasty and is the only drug proven to be effective against heterotopic ossification following acetabular surgery. Following total hip arthroplasty, other non-steroidal anti-inflammatory drugs, including naproxen and diclofenac, are equally as effective as indometacin and can be considered as alternative first-line treatments. Celecoxib is also of equal efficacy to indometacin and is associated with significantly fewer gastrointestinal side effects. However, serious concerns were raised over the safety of selective cyclooxygenase-2 inhibitors for the cardiovascular system and these should be used cautiously.

In vivo comparison of hip mechanics for minimally invasive versus traditional total hip arthroplasty

Background Minimally invasive surgery has been developed to reduce incision length, muscle damage, and rehabilitation time. However, reduced exposure of anatomical landmarks may result in technical errors and inferior implant survivorship. The objective of this study was to compare in vivo motions and hip joint contact forces during gait in total hip arthroplasty subjects, performed with either minimally invasive surgery or standard surgical approaches. Methods Fifteen subjects implanted using either minimally invasive surgery anterolateral, minimally invasive surgery posterolateral, or traditional posterolateral total hip arthroplasty were evaluated using fluoroscopy while performing gait on a treadmill. Kinematics, obtained using 3D-to-2D image registration technique, were input as temporal functions in a 3D inverse dynamic mathematical model that determines in vivo soft tissue and hip contact forces. Findings The subjects implanted with posterolateral and anterolateral minimally invasive surgery demonstrated significantly less separation than those implanted with the traditional approach ( P < 0.01). The minimally invasive surgery subjects also experienced lower average maximum peak forces, with 3.2 body weight for the anterolateral minimally invasive surgery and 2.9 body weight for the posterolateral minimally invasive surgery subjects, compared to 3.5 body weight for the traditional subjects ( P = 0.02 and P = 0.03, respectively). Interpretation This is the first study to compare in vivo weight-bearing kinematics, separation and kinetics for traditional, anterolateral minimally invasive surgery and posterolateral minimally invasive surgery total hip arthroplasty subject groups. Our data indicated in all analyzed parameters differences between the minimally invasive surgery and the traditional groups, with favorable results for the minimally invasive surgery subjects. This may be related, to a reduction in stabilizing soft tissues after a minimally invasive surgery procedure, leading to lower bearing surface forces at the femoral head--acetabular cup interface.

Immune Modulation after Total Hip Surgery

Background: Major trauma affects the immune system, and immunosuppression may render the patients susceptible to septic complications. The purpose of this study was to investigate lipopolysaccharide (LPS)-induced releases of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in whole blood in patients undergoing total hip replacement. Methods: Seven patients (6 females) who underwent elective total hip replacement were included. Ex vivo LPS-induced releases of TNF-α and IL-6 were measured in a whole blood assay at days 1, 6, 9 and 12 postoperatively, using low- and high-dose LPS incubation. At the same time, white blood cell counts were analyzed. Results: The amount of TNF-α release was significantly reduced at days 6 and 12. Compared to monocyte counts, TNF-α release was significantly decreased also at day 9 in low- and high-dose LPS stimulation. IL-6 in plasma was significantly increased at day 1 and normalized thereafter. There were no differences in LPS-induced IL-6 levels compared to the levels before surgery. Conclusion: This in vivo/ex vivo study shows a reduced capacity of whole blood to release LPS-induced TNF-α at day 6 through to day 12 after major orthopedic surgery. Attenuated TNF-α release may contribute to an increased postoperative susceptibility to gram-negative sepsis.

Effectiveness of computer-navigated minimally invasive total hip surgery compared to conventional total hip arthroplasty: design of a randomized controlled trial

BackgroundModerate to severe osteoarthrosis is the most common indication for Total Hip Arthroplasty (THA). Minimally Invasive Total Hip Surgery (MIS) and computer-navigated surgery were introduced several years ago. However, the literature lacks well-designed studies that provide evidence of superiority of computer-navigated MIS over a conventional THA technique. Hence, the purpose of this study is to compare (cost)effectiveness of computer-navigated MIS with a conventional technique for THA. It is our hypothesis that computer-navigated MIS will lead to a quicker recovery during the early postoperative period (3 months), and to an outcome at least as good 6 months postoperatively. We also hypothesize that computer-navigated MIS leads to fewer perioperative complications and better prosthesis positioning. Furthermore, cost advantages of computer-navigated MIS over conventional THA technique are expected.Methods/designA cluster randomized controlled trial will be executed. Patients between the ages of 18 and 75 admitted for primary cementless unilateral THA will be included. Patients will be stratified using the Charnley classification. They will be randomly allocated to have computer-navigated MIS or conventional THA technique. Measurements take place preoperatively, perioperatively, and 6 weeks and 3 and 6 months postoperatively. Degree of limping (gait analysis), self-reported functional status and health-related quality of life (questionnaires) will be assessed preoperatively as well as postoperatively. Perioperative complications will be registered. Radiographic evaluation of prosthesis positioning will take place 6 weeks postoperatively. An evaluation of costs within and outside the healthcare sector will focus on differences in costs between computer-navigated MIS and conventional THA technique.DiscussionBased on studies performed so far, few objective data quantifying the risks and benefits of computer-navigated MIS are available. Therefore, this study has been designed to compare (cost) effectiveness of computer-navigated MIS with a conventional technique for THA. The results of this trial will be presented as soon as they become available.

Routine chemoprophylaxis for deep venous thrombosis in Indian patients: Is it really justified?

Background:Venous thromboembolism (VTE), which consists of deep vein thrombosis (DVT) and pulmonary embolism, is a potentially fatal disease. According to the Western literature, DVT of lower limb veins is one of the most common complications following total hip and knee arthroplasty and surgeries for lower limb fractures. Very few studies have been published from India on the subject and very little is known about the true incidence of the condition. The issue has acquired greater significance in Indian subjects in recent times as there is a manifold increase in the number of joint replacement surgeries and surgeries for lower limb fractures. There are no clear guidelines regarding the prophylaxis for VTE for Indian patients.Materials and Methods:We carried out a prospective study to determine the incidence of DVT. Present study included 125 patients undergoing total knee and hip joint arthroplasty and surgeries for fractures of the lower limb over a three-year period. All the patients underwent duplex ultrasonography between the seventh and 14th postoperative day. No mechanical or chemical form of DVT prophylaxis was used.Results:Only nine patients (7.2%) showed sonographic evidence of DVT and the majority of them resolved without treatment. There was no case of pulmonary embolism.Conclusion:DVT following total joint arthroplasty and surgery for lower limb fractures in Indian patients is not as common as reported in the Western literature. A high level of suspicion and close clinical monitoring is mandatory, routine chemoprophylaxis is perhaps not justified in every patient undergoing lower limb surgery in our opinion. More trials involving a larger number of patients and at multi centers, in future, would be required to confirm the findings of our study.

Time course of thrombosis and fibrinolysis during total hip surgery

Time course of thrombosis and fibrinolysis during total hip surgery

Selecting an agent for prophylaxis of venous thromboembolism

Q: It has become very common to use expensive low-molecular-weight heparins (LMWHs) for prophylaxis of deep venous thrombosis (DVT) in hospitalized medical and surgical patients. How can optimal prophylaxis be maintained while controlling the pharmacy expenses that result from the use of effective but costly antithrombotic agents? A: Over the past decade, the use of LMWHs has expanded exponentially as data and experience with the drugs have accumulated. As a result, hospital expenditures have increased dramatically, prompting many hospitals to evaluate LMWHs for potential formulary restriction or therapeutic interchange. The prevention of thrombotic complications is essential in the hospital setting, as venous thromboembolism (VTE), including DVT and pulmonary embolism (PE), is a major cause of morbidity and mortality in hospitalized patients, with 5–10% of all inpatient deaths associated with PE.1,–3 The frequency of VTE is 150-fold higher in hospitalized patients than in nonhospitalized individuals.4 An estimated 75% of all fatal PEs occur in medical patients, who account for 60% of all hospital admissions. 1 Early mortality rates of 3.8% and 38.9% in patients experiencing DVT and PE, respectively, have been reported.2 Patients undergoing major orthopedic surgery have an increased risk of fatal PE. Approximately 50–60% of patients undergoing total hip or knee replacement or surgery for hip fracture without prophylaxis will develop DVT, and up to 13% will die from PE.5,6 At the most basic level, the mean length of hospital stay increases from 5.4 days in patients who do not develop a DVT or PE to 11.5 and 12.4 days, respectively, in those who develop these complications (p < 0.0001 for both comparisons).6

Time course of thrombosis and fibrinolysis during total hip surgery

Venous thrombosis is common in elective hip surgery, and prophylactic treatment is used up to 12 hours before or after surgery. Recent clinical trials suggested that the timing of initiating prophylaxis significantly influenced the antithrombotic effectiveness. Furthermore, the timing of initiating antifibrinolytic treatment to reduce blood loss has been a question of debate. We studied the time course of coagulation and fibrinolysis at all phases during total hip arthroplasty. Specific markers of thrombosis (prothrombin fragment F1.2) and of fibrinolysis (plasminantiplasmin (PAP) and D-dimer) were examined in eight female and two male patients aged 16–62 years. There was a progressive increase in plasma concentrations of F1.2 during the operation. From the end of operation to 4 hours afterwards, there was no further increase in F1.2. Levels of D-dimer did not change until wound closure, when they began to increase up to 4 hours postoperatively, but there were no changes in PAP during the operation or during the 4-h postoperative period. Therefore, surgery for total hip arthroplasty activates thrombin generation during operation with fibrin degradation at a later stage. These observations harmonize with the notion that the interval between surgery and first administration of antithrombotic treatment is a critical variable.

Role of physiotherapy in peri-operative management in total knee and hip surgery

Knee osteoarthritis (OA) is often associated with pain, functional impairment and various degrees of disability. Physiotherapy in combination with both aerobic and strength training exercises have shown positive effects in both the pre-operative and post-operative period. At the initial stages of osteoarthritis, physical therapy and education can improve the functional outcome and the participation of patients in daily activities. In the case of OA progression and when an operation is the only effective treatment, physiotherapy is very useful in enhancing self-esteem and minimising depression and anxiety for the forthcoming surgery. Post-operative intense physical therapy and Continuous Passive Motion (CPM) application offer remarkable benefits in terms of faster recovery, shorter hospital stay and increase of range of motion. Furthermore, home-based excercises following discharge from the hospital should be encouraged in order to optimise the final result. Although the entire mechanism remains unclear, physical exercise protocols may be beneficial for patients and the health system alike.

MIS THA（小切開人工股関節形成術）の経験

MIS THA（小切開人工股関節形成術）の経験

The tribology of metal-on-metal total hip replacements

Total hip surgery is an effective way of alleviating the pain and discomfort caused by diseased or damaged joints. However, in the majority of cases, these joints have a finite life. The main reason for failure is osteolysis (bone resorption). It is well documented that an important cause of osteolysis, and therefore the subsequent loosening and failure of conventional metal- or ceramic-on-ultra-high molecular weight polyethylene joints, is the body's immunological response to the polyethylene wear particles. To avoid this, interest has been renewed in metal-on-metal joints. The intention of this paper is to review the studies that have taken place within different laboratories to determine the tribological performance of new-generation metal-on-metal total hip replacements. These types of joint offer a potential solution to enhance the longevity of prosthetic hip systems; however, problems may arise owing to the effects of metal ion release, which are, as yet, not fully understood.

Performance of 3 gelatine-based resorbable cement plugs: A study on 15 synthetic femurs and a prospective randomized study on 103 patients

Background Intramedullary plugs are key factors in improving cement fixation of the femoral component. We investigated the performance of 3 commercially available resorbable cement restrictors in vitro and in vivo.Methods We measured the migration of the SEM II, the C-plug, and the REX plug in 15 Sawbones synthetic femurs and in 103 patients during total hip surgery. Cement pressures were also measured distally and proximally in vitro.Results and interpretation Our in vitro results showed poor performance of the C-plug compared with the REX and SEM II plugs. In vivo, the mean migration was least for the SEM plug and most for the C-plug. The smaller sizes performed significantly better than the larger ones for all 3 plug types. The overall in vivo performance of all 3 plug types was unsatisfactory. Differences between the SEM II and REX plugs were small and therefore not significant. The SEM II performed better than the REX, the former being much cheaper and easier to insert. The Rex plug looks promising; however, the insertion device must be improved for better results. The C-plug proved to be unstable.

Systemic and local cytokine patterns during total hip surgery

Objective. Increased levels of inflammatory cytokines have been described in musculoskeletal injury. Total hip replacement is major musculoskeletal surgery, and in the present study this operation was used to investigate systemic and local cytokine patterns during musculoskeletal trauma. Material and methods. Blood was sampled before, during and after surgery in 10 patients given total hip replacement. Samples of arterial blood and local blood from the femoral canal were analysed for proinflammatory and anti‐inflammatory cytokines. Results. Surgery induced significant increases in arterial and local levels of interleukin 6 (IL‐6) (p = 0.000, respectively) with the highest levels at 4 h after operation. There were significantly higher local levels of IL‐6 than arterial levels. Interleukin 1β (IL‐1β) was not significantly influenced by surgery at any time (p = 0.800 and 0.300 for local and arterial levels, respectively), nor was tumour necrosis factor α (TNFα) (p = 0.375 and 0.547 for local and arterial levels, respectively). Local levels were higher than arterial levels for IL‐1β and for TNFα. At the end of the operation, local levels of interleukin 10 (IL‐10) were significantly reduced (p = 0.036), while surgery did not influence the arterial levels of IL‐10 (p = 0.235). There were no significant differences in local and arterial levels of IL‐10 (p = 0.558). Conclusions. The study indicates that a major musculoskeletal operation on otherwise healthy patients is associated with fairly modest reactions of inflammation, both systemically and locally.

Cost-Benefit Analysis of Mis Tha: Model-Based Analysis of the Consequences for Switzerland

The objective of this study was to show model-based economic consequences of minimal invasive surgery total hip arthroplasty (MIS THA). The model is based on hospital and rehabilitation costs and lowering of loss of productivity. This study used conventional THA data from Switzerland and cost-effectiveness MIS THA analysis from the United States. According to our model, a total of 42.1 70.1 million can be saved annually in Switzerland when using MIS THA instead of conventional THA. Annual savings of 7,8 12,9 million result from the significantly shorter hospital stay. The savings potential for rehabilitation costs is 10,5 17,5 million annually. In addition, the productivity loss for the economy is lowered by 23.8 39.7 million annually. According to this economic study we recommend the introduction of MIS techniques in THA. MIS THA surgical techniques may allow the reduction of healthcare costs. Despite the promising economic advantages of MIS THA, clinical studies are necessary to prove long-term benefits.

Cost-benefit analysis of MIS THA: Model-based analysis of the consequences for Switzerland

The objective of this study was to show model-based economic consequences of minimal invasive surgery total hip arthroplasty (MIS THA). The model is based on hospital and rehabilitation costs and lowering of loss of productivity. This study used conventional THA data from Switzerland and cost-effectiveness MIS THA analysis from the United States. According to our model, a total of 42.1 70.1 million can be saved annually in Switzerland when using MIS THA instead of conventional THA. Annual savings of 7,8 12,9 million result from the significantly shorter hospital stay. The savings potential for rehabilitation costs is 10,5 17,5 million annually. In addition, the productivity loss for the economy is lowered by 23.8 39.7 million annually. According to this economic study we recommend the introduction of MIS techniques in THA. MIS THA surgical techniques may allow the reduction of healthcare costs. Despite the promising economic advantages of MIS THA, clinical studies are necessary to prove long-term benefits.

Early Results of 1000 Consecutive, Posterior, Single-Incision Minimally Invasive Surgery Total Hip Arthroplasties

One thousand consecutive cementless total hip arthroplasties performed in 759 patients using a posterior, single-incision, minimally invasive surgical approach were followed prospectively for a minimum of 2 years. All surgeries were performed using a tapered, titanium, cementless femoral component and a press-fit, ingrowth acetabular component. Mean patient age was 62.3 years. Mean incision length was 8.8 cm. Harris hip scores improved from 34 preoperatively to 92 postoperatively. Component position was considered acceptable in 95.3% of patients. Six acetabular components failed to osseointegrate, whereas no femoral component was loose. Radiolucencies were limited to the upper femur and were nonprogressive. Complications and component malpositioning were within accepted standards. This consecutive series of minimally invasive total hip arthroplasties shows that satisfactory results can be consistently achieved using this surgical technique.

Beyond Minimally Invasive Total Hip Surgery with the Anterior Approach

There has been controversy about the benefits of minimally invasive total hip arthroplasty. There cannot be any logical argument against any type of surgery performed with the least amount of soft tissue damage, be it muscles, nerves, blood vessels, or skin. The anterior approach through one or two short incisions and surgery through internervous planes seems to be the most logical. Our series of this approach with an incision as short as possible but as long as necessary has demonstrated its effectiveness in terms of few dislocations, thromboembolic events, minimal intraoperative complications, and minor transient nerve problems. With some modifications and standardization of the procedure, it should be reproducible and safe at other centers. Modular femoral components should make it even more effective.

Increased Cytokine Secretion in Patients with Failed Implants Compared with Patients with Primary Implants

All total joint replacements generate wear debris; yet, some implant prostheses fail while others survive despite the presence of ultrahigh molecular weight polyethylene particulate. It was hypothesized that patients with failed hip implants who have osteolysis will secrete higher inflammatory cytokines than patients receiving total joint replacements. Our study evaluated the peripheral blood monocyte response to varying polyethylene particle volume ratios through cytokine quantification in two patient populations: patients having revision surgery for failed total hip replacements (failed implant group) and patients having primary total hip surgery for osteoarthritis of the hip (primary implant group). We observed elevation of all three proinflammatory cytokines tested (interleukin-6, interleukin-1, and tumor necrosis factor-alpha) in response to polyethylene particulate challenge when compared with the controls in both patient groups. The population with failed implants also had a higher absolute cytokine response to polyethylene exposure compared with the control patients having primary implants. These findings suggest that patients with failed implants have a greater inflammatory cytokine response to polyethylene than seen in patients with primary implants.

Comparison of a urine chemistry analyser and microscopy, culture and sensitivity results to detect the presence of urinary tract Infections in an elective orthopaedic population

Currently elective orthopaedic patients require a microscopy and culture of urine (MSU) to be performed on admission. Between 70-80% of urine cultures are found to be negative for infection, making this practice costly and time consuming. The purpose of this study was to compare the accuracy of a dip stick urine chemistry analyser (Clinitek 50 machine) with a MSU, to detect the presence of nitrites and/or leukocytes in a group of elective orthopaedic surgical patients.Methodology: Using a prospective cohort study design all elective orthopaedic patients who met the study criteria were invited to participate. In total 102 patients undergoing total hip or total knee replacement surgery participated.Results: Results showed that the prevalence of urinary tract infections in patients undergoing total knee or hip surgery, was 14%. High specificity and negative predictive values for the detection of bacterial growth by dip stick urine chemical analysis were found, especially when either the presence of nitrites or leukocytes was used as an indicator.Conclusion: This study has provided valuable baseline data on the accuracy of using photometry techniques as a screening measure, in the detection of UTI, in a sample of orthopaedic patients. While the Clinitek 50 dip stick urine chemistry analyser did not have high sensitivity in identifying those patients with a UTI, it was specific in identifying those patients who did not have an infection. Given the enormous cost in routine screening of these patients and the impact on nursing resources, use of this analyser could have potential nursing resource and financial benefits.

Patients with poor preoperative functional status have high expectations of total hip arthroplasty

Recent reports indicate that patients’ expectations should be assessed as part of routine practice before total hip arthroplasty (THA). A total of 1,103 THA patients preoperatively completed the Hospital for Special Surgery Total Hip Replacement Expectations Survey, an 18-item scale tested for validity and reliability. Patients also completed measures of hip-specific function (American Academy of Orthopaedic Surgeons Hip/Knee Module), and overall physical function (SF-36). Patients with worse preoperative function had higher expectations of THA and were more likely to rate their expectations as very important compared with patients with better function. In multivariate analysis, older patients, men, and those with worse functional status (both hip-specific and overall physical function) had more expectations of THA. Identifying and addressing expectations, particularly possibly unrealistic expectations, are important elements in discussions with patients before THA.