Showing papers in "Journal of Arthroplasty in 2009"
TL;DR: Dabigatran, effective compared to once-daily enoxaparin, showed inferior efficacy to the twice-daily North American enoxAParin regimen, probably because of the latter's more intense and prolonged dosing.
Abstract: Dabigatran, an oral once-daily unmonitored thrombin inhibitor, has been tested elsewhere using enoxaparin 40 mg once daily. We used the North American enoxaparin 30 mg BID regimen as the comparator. This was a double-blind, centrally randomized trial. Unilateral total knee arthroplasty patients were randomized to receive oral dabigatran etexilate 220 or 150 mg once daily, or enoxaparin 30 mg SC BID after surgery, blinded. Dosing stopped at contrast venography, 12 to 15 days after surgery. Among 1896 patients, dabigatran 220 and 110 mg showed inferior efficacy to enoxaparin (venous thromboembolism rates of 31% [P = .02 vs enoxaparin], 34% [P < .001 vs enoxaparin], and 25%, respectively). Bleeding rates were similar, and no drug-related hepatic illness was recognized. Dabigatran, effective compared to once-daily enoxaparin, showed inferior efficacy to the twice-daily North American enoxaparin regimen, probably because of the latter's more intense and prolonged dosing.
638 citations
TL;DR: This study examines the importance of overall coronal alignment as a predictor for revision in patients with primary TKAs and found that outliers in overall alignment have a higher rate of revision than well-aligned knees.
Abstract: A recent study has challenged the premise that well-aligned total knee arthroplasties (TKAs) have better survival than outliers. This study examines the importance of overall coronal alignment as a predictor for revision. Patients with primary TKAs were stratified into neutral, varus, and valgus alignment groups based on the postoperative tibiofemoral angle. In 6070 knees (3992 patients), there were 51 failures (0.84%): 21 (0.5%) in the neutral group, 18 (1.8%) in the varus group, and 12 (1.5%) in the valgus group. The best survival was for overall alignment between 2.4° and 7.2° of valgus. Varus knees failed primarily by medial tibia collapse, whereas valgus knees failed from ligament instability. Outliers in overall alignment have a higher rate of revision than well-aligned knees. The goal of TKA should be to restore alignment within 2.4° to 7.2° of valgus.
564 citations
TL;DR: This is the first study to establish the incidence and risk factors associated with early onset and delayed periprosthetic joint infection in the Medicare patient population.
Abstract: Periprosthetic joint infection is one of the most challenging complications of total joint arthroplasty. We evaluated the incidence of early-onset (less than 2 years) and late-onset (greater than 2 years) periprosthetic joint infection after primary total hip arthroplasty (THA). The Medicare 5% national sample data set (1997-2006) was used to longitudinally follow primary THA patients. Deep infections were identified with the International Classification of Diseases, Ninth Revision, Clinical Modification code 996.66. Kaplan-Meier survivorship curves were compiled with infection as the end point. Cox regression was used to evaluate patient and hospital characteristics. Eight hundred eighty-seven THA infections were identified from 39 929 THA patients. The incidence of infection was 1.63% within 2 years and 0.59% between 2 and 10 years. Comorbidities, sex, procedure duration, and socioeconomic status were found to be significant risk factors. This is the first study to establish the incidence and risk factors associated with early onset and delayed periprosthetic joint infection in the Medicare patient population.
470 citations
TL;DR: Patients with coronal alignment within 3 degrees of neutral had superior International Knee Society and Short-Form 12 physical scores at 6 weeks, 3 months, 6 months, and 12 months after surgery.
Abstract: This is a randomized prospective controlled trial comparing the alignment, function, and patient quality-of-life outcomes between patients undergoing conventional (CONV) and computer-assisted (CAS) knee arthroplasty. One hundred and fifteen patients (60 CAS, 55 CONV) underwent cemented total knee arthroplasty. Three patients were lost to follow-up. Eighty-eight percent (CAS) vs 61% (CONV) of knees achieved a mechanical axis within 3 degrees of neutral (P = .003). Aligning femoral rotation with the epicondylar axis was accurately achieved in CAS and CONV with no significant difference. Patients with coronal alignment within 3 degrees of neutral had superior International Knee Society and Short-Form 12 physical scores at 6 weeks, 3 months, 6 months, and 12 months after surgery. Computer-assisted total knee arthroplasty achieves greater accuracy in implant alignment and this correlates with better knee function and improved quality of life.
412 citations
TL;DR: In this retrospective review study, obesity, diabetes, and younger age were found to be risk factors for joint arthroplasty infection.
Abstract: The study aims to delineate the deep infection rates and infection risk factors for primary total knee and total hip arthroplasty patients. A retrospective review was conducted on 6108 patients from 1991 to 2004. The deep infection cases were compared to the noninfected cohort whereby infection risk factors were identified. Of the 8494 joint arthroplasties, 43 (0.51%) developed a deep infection (30 total knee arthroplasties, 13 total hip arthroplasties). Patients with a body mass index greater than 50 had an increased odds ratio of infection of 21.3 (P < .0001). Diabetic patients were 3 times as likely to become infected compared to nondiabetic patients (P = .0027). Simultaneous bilateral total joint arthroplasties were found to have developed infection 3 times less frequently than those performed as unilateral procedures (P = .0024). The average age in our infection cohort was 64.3 and 68.4 in the noninfected cohort. In this retrospective review study, obesity, diabetes, and younger age were found to be risk factors for joint arthroplasty infection.
346 citations
TL;DR: Patients with a low cumulative error score had a better functional outcome and their length of stay in hospital was 2 days shorter and trends were identified for better function with good sagittal and rotational femoral alignment and good Sagittal and coronal tibial alignment.
Abstract: The aim of this study was to identify what aspects of implant alignment and rotation affect functional outcome after total knee arthroplasty (TKA). One hundred and fifty-nine total knee arthroplasties were performed at the authors' institution between May 2003 and July 2004. All patients underwent an objective and independent clinical and radiological assessment before and after surgery. A computed tomography scan was performed at 6 months. The alignment parameters that were measured included sagittal femoral, coronal femoral, rotational femoral, sagittal tibial, coronal tibial, and femorotibial mismatch. The cumulative error score, which represents the sum of the individual errors, was calculated. Functional outcome was measured using the Knee Society Score. Good coronal femoral alignment was associated with better function at 1 year (P = .013). Trends were identified for better function with good sagittal and rotational femoral alignment and good sagittal and coronal tibial alignment. Patients with a low cumulative error score had a better functional outcome (P = .015). These patients rehabilitated more quickly and their length of stay in hospital was 2 days shorter.
339 citations
TL;DR: Revision TKA procedures were most commonly performed in large, urban, nonteaching hospitals in Medicare patients ages 65 to 74 and the average length of hospital stay was 5.1 days, the average total charges were $49,360, and the most common type of revision TKA procedure reported was all component revision.
Abstract: Understanding the cause of failure and type of revision total knee arthroplasty (TKA) procedures performed in the United States is essential in guiding research, implant design, and clinical decision making in TKA. We assessed the causes of failure and specific types of revision TKA procedures performed in the United States using newly implemented ICD-9-CM diagnosis and procedure codes related to revision TKA data from the Nationwide Inpatient Sample (NIS) database. Clinical, demographic, and economic data were reviewed and analyzed from 60,355 revision TKA procedures performed in the United States between October 1, 2005 and December 31, 2006. The most common causes of revision TKA were infection (25.2%) and implant loosening (16.1%), and the most common type of revision TKA procedure reported was all component revision (35.2%). Revision TKA procedures were most commonly performed in large, urban, nonteaching hospitals in Medicare patients ages 65 to 74. The average length of hospital stay (LOS) for all revision TKA procedures was 5.1 days, and the average total charges were $49,360. However, average LOS, average charges, and procedure frequencies varied considerably by census region, hospital type, and procedure performed.
338 citations
TL;DR: The results of this study suggest more rapid recovery for hip function and gait ability after MIS-THA via a DAA when compared to an MPA.
Abstract: We classified 182 consecutive patients (195 hips) treated by primary cementless minimally invasive total hip arthroplasty (MIS-THA) into 2 groups via the surgical approaches: direct anterior approach (DAA, 99 hips) and a mini-posterior approach (MPA, 96 hips) Ninety-nine percent of the cups in the DAA group and 91% in the MPA group had been implanted within the safe zone (P = 008) Patients in the DAA group could get single-leg stance of more than 5 seconds by 166 days (P = 0004), had positive Tredelenburg's sign by 29%, got 50-m walking time of 523 seconds (P = 017), and showed improvement in the use of assistive walking aids (P = 031) at 3 weeks postoperatively The results of this study suggest more rapid recovery for hip function and gait ability after MIS-THA via a DAA when compared to an MPA
260 citations
TL;DR: Patients with developmental dysplasia of the hip may present with acetabular rim overloading, labral hypertrophy, and tear, and patients with evidence of abnormal hip morphologies may not benefit from hip arthroscopy and isolated treatment of the labrum; in fact, the latter may accelerate the process of arthritis in some patients.
Abstract: Patients with developmental dysplasia of the hip may present with acetabular rim overloading, labral hypertrophy, and tear. Our hypothesis was that isolated arthroscopic treatment of labral tear is likely to fail in most patients. We investigated 34 patients who underwent at least one arthroscopy of the hip for labral tear. Developmental hip dysplasia or other morphologic abnormalities of the hip were confirmed in all patients. Arthroscopy failed to relieve pain in 24 patients. We observed accelerated arthritis in 14 patients and migration of the femoral head in 13 patients. Sixteen patients underwent further surgery (further surgeries included periacetabular osteotomy [6 patients], femoroacetabular osteoplasty [7 patients], and total hip arthroplasty [3 patients]). At the latest follow-up, all patients but one were pain-free. Patients with evidence of abnormal hip morphologies may not benefit from hip arthroscopy and isolated treatment of the labrum; in fact, the latter may accelerate the process of arthritis in some patients.
240 citations
TL;DR: This retrieval study demonstrates that even with a modern taper design and corrosion-resistant materials, increased modularity can lead to fretting and crevice corrosion, metal ion generation, and particulate debris that may contribute to periprosthetic osteolysis and loosening.
Abstract: Since the early 1990s, there has been a dramatic increase in modular total hip designs ranging from a stem with a proximal taper and modular head, to a distal stem, double taper proximal neck, and modular head. Clinical advantages of the modular neck include intraoperative adjustment of leg length via the neck-head taper and femoral anteversion via the neck-stem taper. Sixteen cases of a double tapered cone, Margron hip prosthesis, were presented for retrieval analysis. Macroscopic inspection, corrosion testing, light microscopy, and scanning electron microscopy were conducted to elucidate mechanisms of failure. In this regard, 6 neck components showed significant fretting, and crevice corrosion of the neck-stem taper with an average implantation time of 39 months compared with the remaining retrievals, which showed no corrosion with and average time in situ of 2.7 months. This retrieval study demonstrates that even with a modern taper design and corrosion-resistant materials, increased modularity can lead to fretting and crevice corrosion, metal ion generation, and particulate debris that may contribute to periprosthetic osteolysis and loosening.
220 citations
TL;DR: In this paper, the authors examined the relationship between patient expectations of total joint arthroplasty and functional outcomes and found that a greater expectation of pain relief with surgery independently predicted greater reported pain relief at 1 year of follow-up, adjusted for all relevant covariates.
Abstract: We examined the relationship between patient expectations of total joint arthroplasty and functional outcomes We surveyed 1799 patients undergoing primary hip or knee arthroplasty for demographic data and Western Ontario McMaster University Osteoarthritis Index scores at baseline, 3 months, and 1 year of follow-up Patient expectations were determined with 3 survey questions The patients with the greatest expectations of surgery were younger, male, and had a lower body mass index Linear regression modeling showed that a greater expectation of pain relief with surgery independently predicted greater reported pain relief at 1 year of follow-up, adjusted for all relevant covariates (P < 05) Patient expectation of pain relief after joint arthroplasty is an important predictor of outcomes at 1 year
TL;DR: A systematic review of the literature revealed failure to eradicate infection in 10 of 13 patients managed with a similar protocol, and the total success rate of ODCR in acute periprosthetic MRSA knee infection was 18%.
Abstract: The success of open irrigation and debridement with component retention (ODCR) for acute periprosthetic knee joint infection varies widely. The species and virulence of the infecting organism have been shown to influence outcome. This multicenter, retrospective study identified 19 cases of acute periprosthetic methicillin-resistant Staphylococcus aureus (MRSA) knee infections managed by ODCR and at least 4 weeks of postoperative intravenous vancomycin therapy. At minimum follow-up of 2 years, the treatment failed to eradicate the infection in 16 cases (84% failure rate). Of those 16 failures, 13 patients required a 2-stage exchange arthroplasty, 2 patients required repeat incision and debridement with antibiotic suppression, and 1 patient died of MRSA sepsis. In addition, a systematic review of the literature revealed failure to eradicate infection in 10 of 13 patients managed with a similar protocol. The total success rate of ODCR in acute periprosthetic MRSA knee infection was 18%.
TL;DR: Adequate training is critical to reduce the risk of complications during the learning experience of minimally invasive hip arthroplasty procedures by community practice surgeons.
Abstract: There are no data regarding the efficacy and safety of minimally invasive hip arthroplasty technique performed by community practice orthopedists. The early clinical and radiographic results of primary total hip arthroplasty using a minimally invasive anterior approach to the hip performed on a fracture table were studied. Two hundred thirty-one consecutive patients (247 hips) of 5 community practice surgeons were studied. The average surgical time (164 minutes) and estimated blood loss (858 mL) were more than double, and the major complication rate (9%) was 6 times that reported by an innovator of the procedure. However, no postoperative dislocations occurred. Adequate training is critical to reduce the risk of complications during the learning experience of minimally invasive hip arthroplasty procedures by community practice surgeons.
TL;DR: The revision casel load of surgeons has increased over time, particularly for surgeons with the highest caseloads, particularly at the time of hip and knee arthroplasty operations.
Abstract: We analyzed the temporal changes in the caseload of primary and revision hip and knee arthroplasty surgeons in the United States between 1990 and 2004. The Nationwide Inpatient Sample was used to identify arthroplasty procedures and the surgeons who performed them. Annual caseloads were analyzed for each procedure; 47% +/- 2% and 39% +/- 2% of hip and knee surgeons performed revisions nationwide. Average revision caseloads increased slightly over time at a rate of 1.2 and 1.4 cases per surgeon per decade for total hip arthroplasty (THA) and total knee arthroplasty (TKA), respectively. The caseload of primary THA and TKA increased by 1.4 and 1.7 cases per surgeon per decade. The caseload for the top 5% of primary THA and TKA surgeons increased from 25 to 45 and 33 to 86, respectively, during this period compared with the median caseload, which increased from 4 to 5 (hip) and 5 to 10 (knee). The revision caseload of surgeons has increased over time, particularly for surgeons with the highest caseloads.
TL;DR: A 55-year-old man with a total hip prosthesis (ceramic femoral head and polyethylene inlay) with hypothyroidism, peripheral neuropathy, and cardiomyopathy for the first time is described.
Abstract: Our study describes a 55-year-old man with a total hip prosthesis (ceramic femoral head and polyethylene [PE] inlay). After a fall, the ceramic head broke into several pieces, and a subsequent revision surgery with metal femoral head and PE inlay was performed. Three months later, the so far healthy patient complained of multiorgan symptoms. The subsequent clinical examinations revealed hypothyroidism, peripheral neuropathy, and cardiomyopathy for the first time. In a second revision surgery, a massive deterioration of the metal femoral head by overlooked particles of the broken ceramic head was found. The cobalt concentration in blood exceeded a never before observed level. After replacement of the scraped femoral head, the cobalt concentration decreased considerably, and most of the symptoms disappeared.
TL;DR: TKA patients experience a significantly poorer functional outcome than THA patients 5 to 8 years postoperatively, according to the median Oxford knee score.
Abstract: The aim of this study was to compare the midterm functional outcomes of total knee arthroplasty (TKA) and total hip arthroplasty (THA). A cross-sectional postal audit survey of all consecutive patients who had a primary joint replacement at one orthopedic center 5 to 8 years ago was conducted. Participants completed an Oxford hip score or Oxford knee score, which are self-report measures of functional ability. Completed questionnaires were returned from 1112 THA patients and 613 TKA patients, giving a response rate of 72%. The median Oxford knee score of 26 was significantly worse than the median Oxford hip score of 19 (P < .001). In conclusion, TKA patients experience a significantly poorer functional outcome than THA patients 5 to 8 years postoperatively.
TL;DR: It is demonstrated that residual symptoms or dysfunctions not directly associated with the replaced knee could be a frequent cause of postoperative dissatisfaction after TKA in osteoarthritic patients.
Abstract: We aimed to identify the causes and predictors of patient's dissatisfaction after total knee arthroplasty (TKA) Patient's satisfaction was evaluated in 438 TKAs Causes of patient dissatisfaction were identified using patient interview, physical examinations, laboratory and radiographic tests, and relevant medical consultations Investigation of 33 dissatisfied knees identified knee-related symptoms in 16 knees (485%) and the symptoms unrelated to the replaced knee in 17 knees (515%) Multivariate logistic regression analysis revealed that worse preoperative Western Ontario McMaster University Osteoarthritis Index scale pain score and postoperative decrease in range of motion were significantly associated with postoperative dissatisfaction (odds ratio, 76 and 21, respectively) This study demonstrates that residual symptoms or dysfunctions not directly associated with the replaced knee could be a frequent cause of postoperative dissatisfaction after TKA in osteoarthritic patients
TL;DR: In this article, a questionnaire was distributed to the members of the American Association for Hip and Knee Surgeons attending the 2007 annual meeting inquiring about recommendations for 15 activities for patients with total hip arthroplasty or total knee reconstruction.
Abstract: There are limited data to guide surgeon recommendations regarding activities after total joint arthroplasty. The present study aims to better clarify the current community standards. A questionnaire was distributed to the members of the American Association for Hip and Knee Surgeons attending the 2007 annual meeting inquiring about recommendations for 15 activities for patients with total hip arthroplasty or total knee arthroplasty. One hundred thirty-nine surveys were returned. Spearman rank correlation was used to analyze the data. More than 95% of the responses placed no limitations on low-impact activities including level surface walking, stair climbing, level surface bicycling, swimming, and golf. Higher-impact activities were more commonly discouraged, although there was considerable variability. Recommendations after total hip arthroplasty were more liberal compared to those after total knee arthroplasty. Higher-volume surgeons tended to be more liberal in their recommendations. No responder indicated that there was strong scientific evidence for their recommendations. Investigations are needed to elucidate the long-term effects of higher load and/or higher cycle activities on total joint arthroplasty.
TL;DR: Patients should be made aware of these complications as part of the usual informed consent process before using this technique for postoperative pain control after knee arthroplasty.
Abstract: One thousand one hundred ninety patients underwent knee arthroplasty between January 2004 and July 1, 2007, and received an indwelling continuous infusion femoral catheter for postoperative ropivicaine pump infusion. Catheters were placed using electrical stimulation guidance. For the initial 469 patients (group 1), the continuous infusion ran for 2 to 3 days. In 721 patients, the infusion was discontinued 12 hours after surgery. There were 9 femoral nerve palsies (2 in group 1, 7 in group 2) and 8 major falls (0.7%). The overall complication rate was 1.5%, and the risk of permanent nerve injury was 0.2%. Patients should be made aware of these complications as part of the usual informed consent process before using this technique for postoperative pain control after knee arthroplasty. We did not observe fewer falls when the continuous infusion was stopped 12 hours after surgery.
TL;DR: Although the prevalence of procedure-related complications decreased over time, comorbidities increased, and a slight increase was noticed more recently, significant changes were identified in most variables studied.
Abstract: We analyzed the National Hospital Discharge Survey to elucidate temporal changes in the demographics, comorbidities, hospital stay, in-hospital complications, and mortality of patients undergoing primary total knee arthroplasties (TKAs) in the United States. Three 5-year periods were created (1990-1994, 1995-1999, and 2000-2004), and temporal changes were analyzed. The number of TKAs performed increased by 125% for the 3 periods. The increasing proportion of younger patients was accompanied by a concomitant decrease of Medicare-insured patients. Length of stay decreased from 8.44 to 4.18 days. An increase in the proportion of discharges to long-term and short-term care facilities and in procedures performed in small hospitals was noted. Although the prevalence of procedure-related complications decreased over time, comorbidities increased. Despite a decrease in mortality from the first to the second study period (0.50% vs 0.21%), a slight increase was noticed more recently (0.28%). We identified significant changes in most variables studied.
TL;DR: This economic model predicts a supply side crisis that threatens patient access to specialty care and suggests immediate steps to stimulate supply must be taken.
Abstract: Demand for primary and revision arthroplasty is expected to double in 10 years Coincident with this is a decreased interest in arthroplasty by residents Retirement of arthroplasty surgeons further threatens access This study determines if supply will meet demand Survey data were used to calculate the 2016 workforce Demand in 2016 was estimated using the Nationwide Inpatients Sample Between 2008 and 2016, 400 arthroplasty specialists and 1584 generalists will enter the workforce By 2016, 1896 arthroplasty surgeons will retire using 65 years as a conservative retirement age, whereas 4239 will retire using 59 years as a baseline retirement age In 2016, the model estimated a procedural shortfall ranging from 174,409 (↓186%) using conservative retirement assumptions (age, 65 years) to 1,177,761 (↓694%) using baseline retirement assumptions (age, 59 years) This economic model predicts a supply side crisis that threatens patient access to specialty care Immediate steps to stimulate supply must be taken
TL;DR: Sixteen cases of revision total knee arthroplasty requiring the use of porous tantalum tibial cones after 13 cases of aseptic loosening and 3 cases of staged reimplantation for infection were reviewed, with good short-term results achieved in complex revisions, with these new reconstructive tools.
Abstract: Sixteen cases of revision total knee arthroplasty requiring the use of porous tantalum tibial cones for 2 T2A, 3 T2B, 4 T3A, and 7 T3B tibial bone defects (Anderson Orthopaedic Research Institute classification) after 13 cases of aseptic loosening and 3 cases of staged reimplantation for infection were reviewed. At an average 31 months (24-38), no patients were lost to follow-up. There were 2 cases of recurrent sepsis requiring removal of a well-fixed cone. In the remaining 14 cases, the reconstructions were functioning well with no reoperations. Radiographs demonstrated reestablishment of the joint line, neutral mechanical axis (average, 5.4 degrees of valgus), and signs of stable osteointegration into the cones. Good short-term results were achieved in complex revisions, with these new reconstructive tools.
TL;DR: The ROM improved in a head size-dependent manner primarily because of increasing the jumping distance of the femoral head rather than delaying any impingement, and the effectiveness of femoral offset was driven by delayed osseous impingements.
Abstract: The purpose of this study was to quantify the effects of femoral offset and head size on range of motion (ROM) after total hip arthroplasty. Modular prostheses were implanted into 11 cadaveric hips using a posterolateral approach and tested for ROM with 3 different offsets and 5 different femoral head sizes. Increasing the femoral offset to 4 and 8 mm resulted in 21.1 degrees and 26.7 degrees of improved flexion, and 13.7 degrees and 21.2 degrees of improved internal rotation, respectively. The ROM improved in a head size-dependent manner primarily because of increasing the jumping distance of the femoral head rather than delaying any impingement. In contrast, the effectiveness of femoral offset was driven by delayed osseous impingement.
TL;DR: Despite obvious challenges, advances in fracture management and cementless acetabular fixation in THA demonstrate improved results for posttraumatic arthritis following acetABular fracture.
Abstract: Total hip arthroplasty (THA) outcomes for posttraumatic arthritis after acetabular fracture have yielded inferior results compared to primary nontraumatic THA. Recently, improved results have been demonstrated using cementless acetabular reconstruction. Thirty-two patients underwent THA for posttraumatic arthritis after acetabular fracture; 24 were treated with open reduction internal fixation, and 8 were managed conservatively. Time from fracture to THA was 36 months (6-227 months). Average follow-up was 4.7 years (2.0-9.7 years). Harris Hip score increased from 28 (0-56) to 82 points (20-100). Six patients required revision. Five-year survival with revision, loosening, dislocation, or infection as an end point was 79%. Survival for aseptic acetabular loosening was 97%. Revision surgery correlated with nonanatomic restoration of the hip center and a history of infection (P < .05). Despite obvious challenges, advances in fracture management and cementless acetabular fixation in THA demonstrate improved results for posttraumatic arthritis following acetabular fracture.
TL;DR: Digital templating was determined to be acceptably safe for preoperative planning of primary total hip arthroplasty (THA) operations and to determine if digital Templating is safe.
Abstract: The purposes of this study were to compare the accuracy of acetate and digital templating for primary total hip arthroplasty (THA) and to determine if digital templating is safe. Preoperative planning was performed on 50 consecutive preoperative radiographs during 2005. Templating results were compared with the actual hip implants used. Interrater reliability of acetate templating and accuracy of acetate and digital templating were recorded. Digital measurement overestimated acetabular size (P < .001) and underestimated the femoral size (P = .03). The absolute errors were larger for digital compared with acetate templating; however, mean absolute errors did not differ significantly (acetabulum, P = .090; femur, P = .114). Acetate and digital templating can accurately predict the size of THA implants. Digital templating was determined to be acceptably safe for preoperative planning of primary THA operations.
TL;DR: Besides arthroplasty, decompression was the most frequently performed joint-preserving procedure and may serve as important baseline for understanding the disease.
Abstract: This study was performed to estimate the prevalence of osteonecrosis of the femoral head in Korea. Using medical claims data from the Korean National Health Insurance Corporation, all individuals treated under a diagnosis of osteonecrosis of the femoral head were identified for each year from 2002 to 2006. Among them, the number of true cases was estimated using a randomly collected validation sample of 382 patients for which the actual diagnosis was investigated by authors. The estimated yearly prevalence per 100 000 population ranged from 20.53 (20.13
TL;DR: Bone remodeling of a metaphyseal fixed femoral stem, Mayo Conservative Hip, was characterized by the dual-energy x-ray absorptiometry and a mathematical remodeling model and suggested that the remodeling was largely regulated by the mechanical loading distribution pattern determined by implant design.
Abstract: Bone remodeling of a metaphyseal fixed femoral stem, Mayo Conservative Hip (Zimmer International, Warsaw, Ind), was characterized by the dual-energy x-ray absorptiometry and a mathematical remodeling model. The mean age of the patient was 50.8 years, and the mean follow-up was 5.7 years. As anticipated, bony structure underwent significant remodeling after the short-stemmed femoral arthroplasty with resorption proximally and ingrowth distally/laterally. Theoretical prediction further suggested that the remodeling was largely regulated by the mechanical loading distribution pattern determined by implant design.
TL;DR: The results support previous studies from this institution which demonstrated the effectiveness of a 2-stage reimplantation protocol with a standard 1:8 minimal bactericidal titer for treating infections after THA, including those due to methicillin-resistant organisms.
Abstract: Infection is a devastating complication of total hip arthroplasty (THA). This study aimed to determine whether 2-stage reimplantation is still effective for treating contemporary pathogens, including multidrug-resistant organisms. Records of all cases of infected THAs from 1989 to 2003 were reviewed for data on organism, presence of drug resistance, use of an antibiotic-impregnated spacer, type of reimplant, and success of treatment. Of the 87 protocol patients with 2 years of follow-up, 94.3% (82) underwent reimplantation. The original infection was eradicated in 80 of the 84 hips (78/82 patients), a success rate of 95%. All 21 multidrug-resistant infections were eradicated. There were no major differences in eradication rates when the period was split into 3 sections. These results support previous studies from our institution which demonstrated the effectiveness of a 2-stage reimplantation protocol with a standard 1:8 minimal bactericidal titer for treating infections after THA, including those due to methicillin-resistant organisms.
TL;DR: In this paper, the femoral offset (FO) was measured using computed tomography and a specific image processing software (HIP-PLAN) to determine 3D morphological data of the hip focusing on femoral offsets.
Abstract: Two hundred twenty-three patients with osteoarthritic hips were analyzed using computed tomography and a specific image processing software (HIP-PLAN) to determine 3-dimensional morphological data of the hip focusing on femoral offset (FO) Mean FO was found to be 422 +/- 51 mm, 22 mm greater than the 2-dimensional FO values reported in the literature The FO was found to be above 45 mm in 31% of patients and greater than 50 mm in 12% The error associated with the use of conventional plane x-rays to measure FO was found to be 35 +/- 25 mm, the x-ray technique generally underestimating the measure of FO The sum of acetabular and femoral anteversion was found to be out of the safe zone regarding dislocation risk in 47% of patients
TL;DR: It is shown that trabecular metal acetabular cups and shells with or without the use of modular augments can be effectively used to revise failed acetABular components in patients with substantial pelvic bone loss.
Abstract: The purpose of this study is to evaluate the efficacy of trabecular metal (TM) shells and augments in acetabular revisions with significant pelvic bone loss. We retrospectively reviewed 97 cases of consecutive loose total hip arthroplasty with a minimum of Paprosky grade IIA pelvic bone loss treated with a TM revision acetabular component with or without modular augments. The average Harris hip score improved from 55 preoperatively to 76 postoperatively. At the most recent radiographic evaluation, 88 cups demonstrated no lucent lines, 1 cup had lucent lines but remained well fixed, and 8 cups underwent resection arthroplasty for infection. One cup was revised for chronic instability. There were no aseptic failures in this series. Trabecular metal acetabular cups and shells with or without the use of modular augments can be effectively used to revise failed acetabular components in patients with substantial pelvic bone loss.