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Background: One complication of TKA is postoperative anterior knee pain. Balancing retinacular tissue tension to improve patellar tracking is essential in preventing pain. Lateral release might help balance tension although the quantitative changes in patellofemoral force and pressure differentials after lateral release are unknown.Questions/purposes: We asked if there are differences in patellofemoral forces and pressures for knees resurfaced with standard and gender-specific components and whether lateral release changes these differentials.Methods: We studied six fresh-frozen cadaver knees with native knees and knees that had TKAs with patellofemoral resurfacing using traditional and gender-specific components. The knees were taken through passive ROM, and the means for medial and lateral peak pressure and maximum force were calculated before and after a lateral release was performed.Results: In traditional resurfaced knees, lateral peak pressure was greater than medial peak pressure by 727.6 ± 550.0 kPa and lateral maximum force was greater than medial maximum force by 29.6 ± 15.9 N. Lateral release decreased the pressure (71.4 ± 826.0 kPa) and force (10.0 ± 32.1 N) differentials in the traditional but not in the gender-specific design. In gender-specific resurfaced knees, lateral peak pressure was greater than medial peak pressure by 158.7 ± 360.0 kPa and lateral maximum force was greater than medial maximum force by 15.5 ± 10.4 N. Lateral release increased the pressure (285.7 ± 565.0 kPa) and force (16.8 ± 10.8 N) differentials.Conclusions: Our preliminary data suggest lateral release is more effective in reducing peak pressure and maximum force differentials in knees resurfaced with traditional standard components than with gender-specific components.Clinical Relevance: The lateral release technique might help with tissue balancing when using standard components in TKA. [ABSTRACT FROM AUTHOR]

Background: There has been widespread interest in medical errors since the publication of To Err Is Human: Building a Safer Health System by the Institute of Medicine in 2000. The Patient Safety Committee of the American Academy of Orthopaedic Surgeons has compiled the results of a member survey to identify trends in orthopaedic errors that would help to direct quality assurance efforts.Methods: Surveys were sent to 5540 Academy fellows, and 917 were returned (a response rate of 16.6%), with 53% (483) reporting an observed medical error in the previous six months.Results: A general classification of errors showed equipment (29%) and communication (24.7%) errors with the highest frequency. Medication errors (9.7%) and wrong-site surgery (5.6%) represented serious potential patient harm. Two deaths were reported, and both involved narcotic administration errors. By location, 78% of errors occurred in the hospital (54% in the surgery suite and 10% in the patient room or floor). The reporting orthopaedic surgeon was involved in 60% of the errors; a nurse, in 37%; another orthopaedic surgeon, in 19%; other physicians, in 16%; and house staff, in 13%. Wrong-site surgeries involved the wrong side (59%); another wrong site, e.g., the wrong digit on the correct side (23%); the wrong procedure (14%); or the wrong patient (5% of the time). The most frequent anatomic locations were the knee and the fingers and/or hand (35% for each), the foot and/or ankle (15%), followed by the distal end of the femur (10%) and the spine (5%).Conclusions: Medical errors continue to occur and therefore represent a threat to patient safety. Quality assurance efforts and more refined research can be addressed toward areas with higher error occurrence (equipment and communication) and high risk (medication and wrong-site surgery). [ABSTRACT FROM AUTHOR]

Background: The American Academy of Orthopaedic Surgeons (AAOS) has developed an array of outcomes assessment instruments designed for the efficient collection of outcomes data from patients of all ages with musculoskeletal conditions in all body regions. The Lower Limb Instruments were developed through a process of literature review, consensus-building, and field-testing.Methods: The instruments were distributed to a total of 290 subjects in twenty orthopaedic practices throughout the United States and Canada. Of the 290 patients, seventy each had a diagnosis in the categories of foot and ankle, sports/knee, and hip and knee and forty each had a diagnosis in the categories of trauma and rehabilitation. Retests to be taken twenty-four hours after the first test were distributed to subsamples of patients for each instrument. Seventy-one one-year follow-up questionnaires (twenty-five Sports/Knee, twenty-five Foot and Ankle, sixteen Hip and Knee, and five Lower Limb Core instruments) were returned.Results: The Lower Limb Core Scale and the Hip and Knee Core Scale, each consisting of seven items addressing pain, stiffness and swelling, and function, performed at an acceptable level. Additional Sports/Knee and Foot and Ankle Modules proved to have internal and retest reliability of 0.80 or better, comparable with the values for well-established measures such as the Short Form-36 (SF-36). All of the new scales were moderately to strongly correlated with other measures of pain and function, such as physician ratings, the SF-36, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Seventy-one patients provided follow-up information for the analysis of sensitivity to change. The Lower Limb Core was found to contribute independently to the prediction of the transition score based on the patient and physician assessments of change.Conclusions: The AAOS Lower Limb Instruments for outcomes assessment are highly reliable and are correlated with other measures for similar constructs. They are also sensitive to change in patient status. The Lower Limb Core Scale may be used with attribution of pain either to the lower limb or to a specific joint or side without sacrificing reliability. Combined with the SF-36, the AAOS outcomes assessment instruments comprehensively and efficiently measure outcomes in orthopaedic patients with lower-limb conditions. [ABSTRACT FROM AUTHOR]

Background: VTE is a serious, but decreasing complication following major orthopedic surgery. This guideline focuses on optimal prophylaxis to reduce postoperative pulmonary embolism and DVT.Methods: The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.Results: In patients undergoing major orthopedic surgery, we recommend the use of one of the following rather than no antithrombotic prophylaxis: low-molecular-weight heparin; fondaparinux; dabigatran, apixaban, rivaroxaban (total hip arthroplasty or total knee arthroplasty but not hip fracture surgery); low-dose unfractionated heparin; adjusted-dose vitamin K antagonist; aspirin (all Grade 1B); or an intermittent pneumatic compression device (IPCD) (Grade 1C) for a minimum of 10 to 14 days. We suggest the use of low-molecular-weight heparin in preference to the other agents we have recommended as alternatives (Grade 2C/2B), and in patients receiving pharmacologic prophylaxis, we suggest adding an IPCD during the hospital stay (Grade 2C). We suggest extending thromboprophylaxis for up to 35 days (Grade 2B). In patients at increased bleeding risk, we suggest an IPCD or no prophylaxis (Grade 2C). In patients who decline injections, we recommend using apixaban or dabigatran (all Grade 1B). We suggest against using inferior vena cava filter placement for primary prevention in patients with contraindications to both pharmacologic and mechanical thromboprophylaxis (Grade 2C). We recommend against Doppler (or duplex) ultrasonography screening before hospital discharge (Grade 1B). For patients with isolated lower-extremity injuries requiring leg immobilization, we suggest no thromboprophylaxis (Grade 2B). For patients undergoing knee arthroscopy without a history of VTE, we suggest no thromboprophylaxis (Grade 2B).Conclusions: Optimal strategies for thromboprophylaxis after major orthopedic surgery include pharmacologic and mechanical approaches. [ABSTRACT FROM AUTHOR]

Background: Total joint arthroplasty procedures continue to provide consistent, long-term success and high patient satisfaction scores. However, early unplanned readmission to the hospital imparts significant financial risks to individual institutions as we shift away from the traditional fee-for-service payment model., Methods: Using a combination of our hospital's administrative database and retrospective chart reviews, we report the 30-day and 90-day readmission rates and all causes of readmission following all unilateral, primary elective total hip and knee arthroplasty procedures at a large, urban, academic hospital from 2004 to 2013., Results: In total, 1165 primary total hip (511) and knee (654) arthroplasty procedures were identified, and the 30-day and 90-day unplanned readmission rates were 4.6% and 7.3%, respectively. A multivariate regression model controlled for a variety of potential clinical and surgical confounders. Increasing body mass index levels, an American Society of Anesthesiologists score of ≥3, and discharge to an inpatient rehab facility each independently correlated with risk of both 30-day and 90-day unplanned readmission to our institution. Additionally, use of general anesthesia during the procedure independently correlated with risk of readmission at 30 days only, while congestive heart failure independently correlated with risk of 90-day unplanned readmission. Readmissions related directly to the surgical site accounted for 47% of the cases, and collectively totaled more than any single medical or clinical complication leading to unplanned readmission within the 90-day period., Conclusion: Increasing body mass index values, general anesthesia, an American Society of Anesthesiologists score of ≥3, and discharge to an inpatient rehab facility each were independent risk factors for early unplanned readmission., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: This study investigated the risk and cost of postoperative complications associated with morbid and super obesity after total knee arthroplasty (TKA)., Methods: A retrospective cohort study was conducted of patients who underwent TKA using Medicare hospital claims data. The International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code V85.4x was used to identify morbidly obese patients (body mass index [BMI] ≥40 kg/m(2)) and superobese patients (BMI ≥50 kg/m(2)) in 2011-2013. Patients without any BMI-related diagnosis codes were used as controls. Twelve complications occurred in the 90-day period after TKA were analyzed using multivariate Cox models, adjusting for patient demographic, morbidity, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through subsequent 90 days., Results: Morbidly obese patients showed a significantly elevated risk in most complications examined, with a 2-fold or higher risk in dislocation and wound dehiscence. In addition, death, periprosthetic joint infection, acute renal failure, and knee revision had significant hazard ratios between 1.5 and 2.0. However, risk of deep vein thrombosis and acute myocardial infarction did not increase for the morbidly obese patients. Superobese patients had significant increase in risk of infection, wound dehiscence, acute renal failures, revisions, death, and readmission compared with patients with BMI 40-49 kg/m(2). Significant dose-response trend was found between the level of BMI and risk for death, dislocation, implant failure, infection, readmission, revision, wound dehiscence, and acute renal failure. Controlling for patient and institutional factors, each TKA had an average total hospital charges of $75,884 among superobese patients, compared to $65,118 for the control group, a difference of $10,767. Medicare payment for the superobese patients was also higher, but only by $2703., Conclusion: Morbidly obese patients pose a significantly higher risk profile than normal-weight patients in a broad range of complications after TKA. Superobese patients add another layer of risk compared with less obese patients and are considerably more expensive to treat by health care systems. Technical difficulties and the high demand on resources present a severe challenge for providing treatment for such patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Identifying BMI via administrative data is a useful way to evaluate outcomes in total joint arthroplasty (TJA) for varying degrees of obesity. The purpose of this study was to evaluate the concordance between BMI coding in administrative claims data and actual clinical BMI measurements in the medical record for patients undergoing TJA. Clinical BMI value was shown to be a significant determinant of whether ICD-9 codes were used to report the patient's obesity status (P<0.01). Although a higher clinical BMI strongly increased the likelihood of having either of the ICD-9 diagnosis codes used to identify obesity status, only the accuracy of the V85 code increased with increasing levels of BMI., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We used our database of primary total hip arthroplasties to identify those patients who had acetabular fractures fixed with percutaneous screws under the same anesthesia as for the arthroplasty procedure. There were 19 patients with the average follow-up of 22 months. Fourteen patients sustained the fracture secondary to a low-energy trauma, while the remaining patients were involved in a high-energy trauma accident. The mean survival time was calculated to be 2.5 ± 0.6 years for the low-energy group and 4 ± 1.4 years for the high-energy group. We believe that this unique treatment of acetabular fractures has a role in carefully selected patients and provides the necessary reduction and immediate stability of the fracture needed to ensure adequate fit for the acetabular cup in the subsequent THA., (© 2014.)

A private payer database was used to examine the incidence and rates of knee arthroscopy in patients less than 65 years of age and the subsequent risk of knee arthroplasty. Time to event analysis was performed using the Kaplan-Meier method; also, Cox regression analysis was used to evaluate the relative risk of subsequent knee arthroplasty for arthroscopic patients. Overall, 247,034 knee arthroscopies, done for injury or arthropathy, were identified between 2004 and 2009. Within 1-year of arthroscopy, 2.2% of arthropathy patients and 0.9% of injury patients underwent a knee arthroplasty. These increased to 5.2% and 2.4% at 5-years, respectively. The risk of arthroplasty following arthroscopy increased significantly with age. Further study is warranted to examine the benefit of arthroscopy in younger patients with OA., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Patients treated with total hip or knee arthroplasty are at risk for venous thromboembolic disease. Laboratory evaluation of thrombophilia can help to better identify patients at higher risk for venous thromboembolic disease, and newer methods that test for genetic factors continue to evolve; however, more research is needed to justify routine testing for thrombophilia. Research studies have yielded differing results in determining the most appropriate prophylactic regimen. Both pharmaceutical and mechanical treatments are commonly used for prophylaxis. New pharmacologic prophylaxes include the Xa inhibitor rivaroxaban and the thrombin inhibitor dabigatran etexilate. The newest mechanical device used to prevent venous thromboembolism is a miniature, mobile, battery-operated pneumatic system called Continuous Enhanced Circulation Therapy. The American College of Chest Physicians guidelines and the American Academy of Orthopaedic Surgeons clinical guideline were reviewed to directly compare specific agents and balance the risks of venous thromboembolism. Future studies for venous thromboembolic prophylaxis will continue to evaluate new oral agents, improved pneumatic compression devices, and improved methods to decrease bleeding in the immediate postoperative period.

Purpose: To demonstrate that lateral to medial patellofemoral force and pressure ratios could be a surrogate marker of retinacular tension and patellar tracking., Methods: The patellofemoral forces of six knees from three fresh-frozen half-body female cadavers were evaluated with a capacitive sensor under simulated operative conditions in six staged clinical scenarios: native knees, knee arthroplasty without patellar resurfacing, resurfaced knee and patella, resurfaced knee and patella with lateral release, gender-specific knee arthroplasty with patella resurfacing, and gender-specific knee arthroplasty with lateral release. Maximum force and peak pressure were simultaneously recorded during three to four ranges of motion. Average values were compared between lateral and medial patellofemoral compartments as an objective measure of patellar tracking for the different settings., Results: Significant differences in lateral and medial force and pressure differentials were seen in most scenarios despite clinically normal patellar tracking. Lateral to medial ratios of maximum force and peak pressure significantly increased after TKA (2.9, 2.1) and after patella resurfacing (2.8, 2.6) compared to the native knee (1.6, 1.8). Addition of a lateral release in resurfaced knees decreased the ratio of lateral to medial patellofemoral forces and pressures as did gender knee arthroplasty (1.5 and 1.1, 2 and 1.3, respectively). Pressure and force values most closely resembled the native knee in the resurfaced knee/resurfaced patella with lateral release and in the gender knee arthroplasty scenarios., Conclusions: Use of lateral to medial patellofemoral force ratios as a surrogate objective marker for patellar tracking was validated in this study by decreasing ratios observed after lateral release in TKA and with gender-specific implants.

This study reviewed all applications to our residency program and all interviewees completed a standardized questionnaire. Data was collected on applicants' educational background, knowledge of the residency program, and geographical considerations. All rotating applicants (21/46) knew the correct name of the chairman and program director, and knew the program size, compared with non-rotating applicants (25/46). Applicants applied to the programs within our city limits more often (80%) than to programs furthest from the city limits (63%). These data suggest that factors including size, rotations, research, and operative experience, may be less important than geographical considerations for medical students choosing an orthopedic surgery residency.

Background: Bone quality should play an important role in decision-making for orthopaedic treatment options, implant selection, and affect ultimate surgical outcomes. The development of decision-making tools, currently typified by clinical guidelines, is highly dependent on the precise definition of the term(s) and the appropriate design of basic and clinical studies. This review was performed to determine the extent to which the issue of bone quality has been subjected to this type of process., Questions/purposes: We address the following issues: (1) current methods of clinically assessing bone quality; (2) emerging technologies; (3) how bone quality connects with surgical decision-making and the ultimate surgical outcome; and (4) gaps in knowledge that need to be closed to better characterize bone quality for more relevance to clinical decision-making., Methods: PubMed was used to identify selected papers relevant to our discussion. Additional sources were found using the references cited by identified papers., Results: Bone mineral density remains the most commonly validated clinical reference; however, it has had limited specificity for surgical decision-making. Other structural and geometric measures have not yet received enough study to provide definitive clinical applicability. A major gap remains between the basic research agenda for understanding bone quality and the transfer of these concepts to evidence-based practice., Conclusions: Basic bone quality needs better definition through the systematic study of emerging technologies that offer a more precise clinical characterization of bone. Collaboration between basic scientists and clinicians needs to improve to facilitate the development of key questions for sound clinical studies.

The purpose of this study was to use a validated capacitive pressure (Novel Electronics, Inc, St Paul, Minn) in the measurement and distribution of patellofemoral forces and pressures during simulated operative procedures. Six fresh frozen cadaver knees were evaluated through a range of motion and observations recorded in native knees (NKNP) with sequential resurfacing of tibiofemoral (RKNP) and patellofemoral (RKRP) articulations with standard and gender (GKRP) components. Significant lateral-medial maximum force differentials were observed for all conditions. Significant lateral-medial peak pressure differentials were observed in RKNP and RKRP. A significant decrease in lateral maximum force from RKRP to GKRP (P = .01) was observed. Significant increases in lateral peak were seen from NKNP to RKNP (P = .04) and RKNP to RKRP (P = .047), whereas a significant decrease was seen from RKRP to GKRP (P < .01). Achieving a quantitative intraoperative assessment of patellar tracking and soft tissue balancing may offer benefits in terms of intraoperative decision making. This is the first reported study to simulate quantitative, intraoperative assessments of patellofemoral pressure and force., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Preoperative classification of acetabular bone loss in revision total hip arthroplasty has been problematic. An evidence-based approach involves having a validated and widely accepted system of classification. A prerequisite would be a system that describes each defect in terms that are mutually exclusive, hierarchical, surgically relevant, and corresponding to experienced clinicians' preoperative estimates of surgical complexity. Of the 6 systems reviewed, only 1 demonstrated the reliability and validity required for a standardized grading system. Although high-grade defects were seen in only 17% of the 1094 hips, the failure rate associated with them was 30%. A larger population of high grade defects is necessary to determine which treatment alternatives are successful., ((c) 2010 Elsevier Inc. All rights reserved.)

Most descriptions of the extensor mechanism of the knee do not take into account its complexity and variability. The quadriceps femoris insertion into the patella is said to be through a common tendon with a three-layered arrangement: rectus femoris (RF) most superficially, vastus medialis (VM) and lateralis (VL) in the intermediate layer, and vastus intermedius (VI) most deeply. We dissected 20 limbs from 17 cadavers to provide a more detailed description of the anterior components of the knee: the tendon, the patellar retinacula, and the patellofemoral ligaments. Only three of the 20 specimens exhibited the typically described quadriceps pattern. The remainder had bilaminar and even more complex trilaminar and tetralaminar fiber arrangements. We found an oblique head of the vastus lateralis (VLO), separated from the longitudinal head by a layer of fat or fascia, in 60% of the specimens. However, we found no distinct oblique head of the vastus medialis (VMO) in any specimen. The medial patellofemoral ligament (MPFL) was more common than the lateral (LPFL), supporting its suggested role as the principal passive medial stabilizer of the patella. Because the quadriceps muscle group plays a direct role in patellofemoral joint function, investigation into the clinical applications of its highly variable anatomy may be worthwhile with respect to joint dysfunction and failures of TKAs.

Isolated greater trochanter fractures after total hip arthroplasty are associated with major comorbidities such as debilitating weakness, pain, and dislocation. No definitive standard of care has been established for these fracture. However, it is well known that reestablishing osseous union in these patients is strongly associated with return of functional status. We report a case of an elderly patient with multiple hip revision surgeries now presenting with unilateral greater trochanter fracture. Treatment incorporated the use of a trochanteric claw plate, cerclage wiring, and adjuvant demineralized bone matrix allograft to achieve successful osseous union. This is the first reported use of adjuvant demineralized bone matrix for fixing these fractures.

This clinical practice guideline is based on a systematic review of published studies on the management of adult patients undergoing total hip replacement (THR) or total knee replacement (TKR) aimed specifically at preventing symptomatic pulmonary embolism (PE). The guideline emphasizes the need to assess the patient's risk for both PE and postoperative bleeding. Mechanical prophylaxis and early mobilization are recommended for all patients. Chemoprophylactic agents were evaluated using a systematic literature review. Forty-two studies met eligibility criteria, of which 23 included patients who had TKR and 25 included patients who had THR. The following statements summarize the recommendations for chemoprophylaxis: Patients at standard risk of both PE and major bleeding should be considered for aspirin, low-molecular-weight heparin (LMWH), synthetic pentasaccharides, or warfarin with an international normalized ratio (INR) goal of < or =2.0. Patients at elevated (above standard) risk of PE and at standard risk of major bleeding should be considered for LMWH, synthetic pentasaccharides, or warfarin with an INR goal of < or =2.0. Patients at standard risk of PE and at elevated (above standard) risk of major bleeding should be considered for aspirin, warfarin with an INR goal of < or =2.0, or none. Patients at elevated (above standard) risk of both PE and major bleeding should be considered for aspirin, warfarin with an INR goal of < or =2.0, or none.

Arthrodesis is one of the last options available to obtain a stable, painless knee in a patient with a damaged knee joint that is not amenable to reconstructive measures. Common indications for knee arthrodesis include failed total knee arthroplasty, periarticular tumor, posttraumatic arthritis, and chronic sepsis. The primary contraindications to knee fusion are bilateral involvement or an ipsilateral hip arthrodesis. A variety of techniques has been described, including external fixation, internal fixation by compression plates, intramedullary fixation through the knee with a modular nail, and antegrade nailing through the piriformis fossa. Allograft or autograft may be necessary to restore lost bone stock or to augment fusion. For the carefully selected patient with realistic expectations, knee arthrodesis may relieve pain and obviate the need for additional surgery or extensive postoperative rehabilitation.

Massive osteolytic bone loss in revision total knee arthroplasty has been an uncommon challenge. From 2001 to 2002, 11 knees in 10 patients underwent revision of failed modular PFC (Johnson and Johnson Orthopaedics, Raynham, Mass) total knee arthroplasties with distal femoral allografts and long-stemmed revision implants for massive osteolytic induced femoral bone loss. The mean follow-up was 42 months (range, 36-48 months). Radiographic graft incorporation was demonstrated in all 11 knees with no cases of loosening. The Knee Society Pain Scores improved by an average of 25.4 points, and the function scores improved by an average of 23.3 points. The outcomes of distal femoral allografts in the reconstruction of massive osteolytic bone loss associated with failed modular PFC (Johnson and Johnson Orthopaedics) total knee arthroplasties are favorable.

Controversy exists regarding the use of cementless femoral fixation for hip arthroplasties in elderly patients. This study reviews the clinical and radiographic outcomes of cementless bipolar hemiarthroplasties in patients older than 65 years of age. From 1998 to 2000, 256 cementless bipolar hemiarthroplasties were performed in 248 patients with displaced femoral neck fractures who had a mean age of 77 years. The mean final follow-up was 3.5 years and Harris hip scores averaged 82 points. Two loose femoral stems were revised and the rest of the implants were radiographically stable and demonstrated evidence of bone ingrowth. Six patients had debilitating groin pain necessitating conversion to total hip arthroplasty. Cementless bipolar hemiarthroplasty can be safely performed in elderly patients and can provide predictable clinical and radiographic results.

Background: There exists variation over geographic areas in the use of total hip arthroplasty. This variation is not explained by the variation in the density per unit area of surgeons. The objective was to compare the severity of hip symptoms between a population-based sample of community-dwelling Medicare beneficiaries and a hospital-based sample of patients undergoing total hip replacement surgery., Material/methods: Population-based survey data on 113 community residents were compared to data from an independent sample of 157 hospital-based patients who underwent total hip replacement surgery, all of whom were 65 years and older. Severity of symptoms in both groups was rated using the Hip Rating Questionnaire (HRQ)., Results: The average population sample HRQ score was 63+/-9.0; overall arthritis impact 12+/-5, pain 14+/-6, walking 18+/-4, function 19+/-4. The average patient sample HRQ score was 56+/-14; overall arthritis impact 10+/-7, pain 11+/-4, walking 15+/-4, function 20+/-3., Conclusions: Community-dwelling individuals report symptoms as severe as patients who have undergone total hip arthroplasty. Further research is necessary to identify the reasons for the low incidence of treatment for those living in the community.

Periprosthetic supracondylar femur fractures following total knee arthroplasty (TKA) are an infrequent, but devastating, complication. From 1998 to 2000, we treated 30 supracondylar femur fractures above TKAs. Eighteen fractures were managed with retrograde intramedullary rod fixation (FIMR) and the other 12 fractures with traditional open reduction with internal fixation (ORIF). Follow-up averaged 3 years, with Knee Society knee scores being 84 and 82, respectively. Complications included 1 above-knee amputation for deep sepsis and 1 nonunion with varus alignment. FIMR appears to be the treatment of choice when it is feasible. However, traditional ORIF also may yield satisfactory results in those designs that cannot accommodate retrograde FIMR fixation.

Previous classifications of severity for total knee arthroplasty revisions have been based largely on bone loss of the femur and tibia. These approaches failed to address the more technically difficult issues in revision surgery such as surgical exposure, contractures, extremity alignment, implant removal, soft tissue stability (in the anteroposterior and in the sagittal planes), extensor mechanism integrity, and patellar revisability. Through the Knee Society, the authors developed a severity index that incorporated these latter factors into one measure. The current authors describe the application of the Knee Society Index of Severity for failed total knee arthroplasty and its method of scoring.

Compared with primary knee replacement, total knee arthroplasty revision surgery is a more complex procedure and accounts for greater expenditures of healthcare resources at each clinical stage. Overall, patients having revision procedures have poorer functional outcomes and higher complication rates than patients having primary arthroplasty. Despite the expanded scope of revision problems and the rapidly emerging technology in revision surgery, the long-term success of any method remains in question. Because there is little consensus on the timing of revision surgery, optimal surgical reconstruction, and the type of prosthesis to be implanted, the Knee Society began development of an Index of Severity for Failed Total Knee Arthroplasty. Fifty-four percent of Knee Society members completed an 82-item questionnaire that determined their clinical impression about potential risk factors for the outcomes of revision surgery for failed total knee replacements. Using these results, a consensus group developed the final version of the index. The result of the nominal group process was the Knee Society Index of Severity, which was based on eight distinct domains. Each domain was divided into attributes and weights based on the questionnaire responses and consensus meeting. Actual case scenarios from five institutions were used to test interrater reliability and validity. The interrater reliability of the average score of all ratings was 0.95; the correlation of the criterion rating with the mean rating was 0.77. When three outliers were not included, the Pearson product correlation increased to 0.92. These data support the application of the Knee Society Index of Severity as a critical component of risk factor studies, effectiveness research, and cost-effectiveness analysis involving revisions of total knee replacements.

TH1 cytokines have recently been detected in rheumatoid arthritis (RA) and osteoarthritis (OA). For this reason we studied the TH-1-promoting cytokine IL-12 in synovial membranes from patients with RA and OA. IL-12 transcripts and protein were analyzed by reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemistry, respectively. In addition, IL-12 transcripts were quantitated by competitive PCR. IL-12 transcripts (p40) were detected in 8 of 13 patients with RA and in 10 of 18 patients with OA. Their levels did not differ significantly between RA and OA. IL-12 heterodimer protein was detected by immunostaining using an anti-IL-12p70 mAb. Double labeling with anti-IL-12p70 and anti-CD68 mAbs showed that synovial lining cells and monocytes/macrophages expressed IL-12 p70 protein. The presence of IL-12 p70 protein in the synovial membranes of patients with RA and OA suggests that IL-12 may play an important immunoregulatory role in these diseases by perpetuating inflammation., (Copyright 1998 Academic Press.)

The effectiveness and safety of warfarin were compared with those of a low-molecular-weight heparin (dalteparin) for the prevention of deep-vein thrombosis after total hip arthroplasty in a prospective, randomized, multi-institutional trial. Patients who were older than eighteen years of age and were scheduled to have an elective primary or revision total hip arthroplasty were eligible; 580 patients were randomized, 550 had the operation and received prophylaxis, and 382 had evaluable venograms. Prophylaxis was provided either with warfarin beginning the night before the operation or with dalteparin beginning two hours before the operation and was continued until venography was performed. Bleeding was assessed on the basis of intraoperative blood loss, transfusion requirements, a decrease in hematocrit, and clinically identified bleeding complications. The prevalence of deep-vein thrombosis was found to be significantly lower in the patients who had received dalteparin than in those who had received warfarin (twenty-eight [15 per cent] of 192 patients compared with forty-nine [26 per cent] of 190 patients; p = 0.006). Deep-vein thrombosis occurred in the calf veins of twenty-one patients (11 per cent) who had received dalteparin and of forty-three patients (23 per cent) who had received warfarin; this difference was significant (p = 0.003). Proximal deep-vein thrombosis occurred in ten patients (5 per cent) who had received dalteparin and in sixteen patients (8 per cent) who had received warfarin; however, with the numbers available, no significant difference could be detected (p = 0.185). We also could not detect a significant difference with regard to the intraoperative and postoperative blood loss, the decrease in hematocrit, and the prevalence of major bleeding complications between the two groups; however, the patients who had received dalteparin had a significantly higher prevalence of bleeding complications involving the operative site (p = 0.03), and a significantly greater percentage required postoperative transfusions (p = 0.001). We concluded that preoperative prophylaxis with dalteparin is significantly more effective than that with warfarin in preventing deep-vein thrombosis after total hip arthroplasty. The greater effectiveness of dalteparin must be considered, however, in light of an increased need for postoperative transfusions and an increase in the prevalence of wound-related bleeding complications.

Although there have been many studies focusing on the increasingly important assessment of patients' satisfaction, few studies have specifically addressed this tissue for total hip arthroplasty (THA). The goals of this study were to measure patients' satisfaction with THA and to evaluate the relationships of expectations and outcome to patients' satisfaction. A total of 180 patients were surveyed 2 to 3 years after THA about their experiences with THA. Patients cited 45 different expectations, which were grouped into five categories reflecting improvement in pain, walking, psychological state, essential activities, and nonessential activities. Overall, 89% of patients were satisfied with the results of surgery. Lower rates of satisfaction were found in patients who had a better preoperative condition (as measured by the surgeons with The Hospital for Special Surgery Hip Scale), in patients who expected improvement in nonessential activities, and in patients who reported worse postoperative condition (as measured by self-assessment with the Hip Rating Questionnaire and the Medical Outcomes Study Short-form General Health Survey). Patients were also asked how they came to THA. Nearly 50% of patients were first referred to an orthopaedist by family or friends or based on their own knowledge. Seventy-four percent either had subsequently referred others for THA or would have done so if they knew someone with hip pain. This study demonstrates that satisfaction with THA is a complex phenomenon, affected by expectations, outcome, and what patients know about the procedure from their community network. A better understanding of THA satisfaction will enable better future selection of patients and an additional dimension of outcome, both of which are important to patients and payers.

A lack of consensus regarding the indications for total hip arthroplasty (THA) and total knee arthroplasty (TKA) has been cited as one reason for the variations in the rates of THA and TKA across the United States. The purposes of this study were to survey orthopaedists in a specific geographic area (New York City) regarding the candidacy of patients with osteoarthritis for THA or TKA and to compare indications for THA between orthopaedists at two academic medical centers, The Hospital for Special Surgery in the United States and McGill University in Canada. Orthopaedists were sent mail surveys asking about indications, factors affecting outcomes, and factors that might modify decisions for surgery. Approximately 45% of orthopaedists who performed THA and TKA in New York City in 1992 completed the surveys. Although there were wide variations among surgeons, most surgeons required at least severe pain daily, rest pain several days per week, transfer pain either several days per week (THA) or daily (TKA), and destruction of most of the joint space on radiograph. Younger age, comorbidity, technical difficulties, and lack of motivation modified the decision against surgery, whereas the desire to be independent and return to work swayed the decision for surgery. Most surgeons rated that patients with severe pain, osteoarthritis, or rheumatoid arthritis would have a high likelihood of an excellent outcome, whereas those with comorbidity and certain technical factors would have only a moderate likelihood of an excellent outcome. In the U.S.-Canadian survey of THA, in which more than 90% of surgeons responded, Canadian surgeons tended to require more frequent pain and use of assistive devices for walking. Although there was a majority of opinion for several indications, there was no clear consensus among surgeons regarding the indications for THA and TKA. Possible explanations for this are that isolated indications are not as important as integrating and weighing several indications and that the patient's desire to proceed with THA or TKA is an important driving force in the decision to operate.

The purpose of this study was to develop a method for directly measuring bone density of femoral neck sections. Three types of density were measured. Real density equals wet weight divided by the actual volume of bone tissue (real volume). Apparent density equals wet weight divided by the total volume occupied by the bone plus the pore spaces (total sample volume). Ash density equals the ash weight divided by the real volume. Corticocancellous cross-sections of the femoral neck were analyzed for density at two levels: level 1, proximal neck and level 3, distal neck. Density measurements were compared with histomorphometric measurements performed on cross-sections at the midportion of the femoral neck (level 2) and with a clinical radiographic measure of bone density (cortical index 3 cm below the lesser trochanter). No correlation was found between apparent density and either real (r = .12, P = .62) or ash density (r = -.09, P = .72) within a given femoral neck section. There was, however, a strong correlation between real and ash density (r = .93, P = .0001). This was expected because real and ash densities are both reflections of bone mineralization. Apparent density showed better correlation, when comparing level 1 with level 3 sections (r = .76, P = .0001), than did ash (r = .57, P = .01) or real density (r = .55, P = .01). There was no correlation between either real or ash density with any histomorphometric parameter. Apparent density was moderately correlated with total bone area expressed as a percentage of cross-sectional area (r = .66, P = .008). This finding tends to validate the direct measurement of apparent density in that both apparent density and total bone area are measurements of the concentration of bone in space. No significant correlation was found between any of the density measurements and the cortical index at 3 cm. This underscores the necessity for precisely qualifying any definition or discussion of bone quality. The success or failure of hip implants may be at least partially determined by the ability of the bone to withstand the insult of implantation of the prosthesis and to adapt successfully to the new mechanical environment. This study represents an early phase of defining parameters that may have prognostic value in long-term implant fixation.

We analyzed the variations in the rates of elective total hip and total knee arthroplasties for 1988 in the United States to determine whether the rates correlated with the numbers of surgeons. There were 56,204 total hip arthroplasties and 68,491 total knee arthroplasties, performed in the home states of the patients among all of the Medicare beneficiaries. Medicare beneficiaries include most people who are more than sixty-five years old in the United States and a small proportion of younger people who are eligible for Medicare for other reasons. Seventy-nine per cent of the patients who had had a total hip arthroplasty and 89 per cent of those who had had a total knee arthroplasty had been managed with the operation because of osteoarthrosis. Both operations were most common in the seventy to seventy-four-year age-group. We calculated the rate of operations per 100 beneficiaries for each state and age-adjusted the results. Across all of the states, bilateral procedures constituted 1.6 per cent of the total hip arthroplasties and 4.8 per cent of the total knee arthroplasties. The in-hospital rates of mortality were 0.72 per cent for total hip arthroplasties and 0.45 per cent for total knee arthroplasties. The destinations after discharge from the hospital were similar for the two groups of patients, with more than 65 per cent of the patients being discharged directly to their homes. There were no significant differences among states in terms of the length of stay in the hospital or reimbursement of the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

The hip-rating questionnaire was developed for the assessment of the outcome of total hip replacement. The purpose of this study was to evaluate its reproducibility, validity, and responsiveness. The questionnaire uses a 100-point scale in which equal weight is given to the domains of global or over-all impact of arthritis, pain, walking, and function. Ninety-eight patients were enrolled in the prospective study and have been followed for at least three months; sixty-two patients have been followed for six months; and forty-two patients have been followed for one year. Reproducibility was tested with the use of the kappa statistic in fifty patients whose condition was stable clinically, and it was found to be good or excellent both for individual questions and for the total score. The validity of the questionnaire was assessed by comparison with the scores from a six-minute walking-distance test and arthritis impact-measurement scales. The result of the six-minute walking-distance test correlated with the patient's response concerning walking distance on the hip-rating questionnaire. The score for pain from the hip-rating questionnaire correlated well with the score for pain from the arthritis impact-measurement scales, and the total score from the hip-rating questionnaire correlated well with the total score from the arthritis impact-measurement scales. The score on the hip-rating questionnaire was responsive to the change in the clinical condition of the patient, as indicated by a favorable index of responsiveness. The results of the questionnaire were sensitive enough to demonstrate differences among treatment groups with relatively small sample sizes. This questionnaire has the characteristics of a useful instrument for assessment of outcomes, such as that after an operation.

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease affecting primarily young women. Osteonecrosis of the femoral head produces significant morbidity in these patients. The clinical and radiographic results of 33 total hip arthroplasties (THA) in 25 patients were studied. The Hospital for Special Surgery hip rating was good or excellent in all surviving index primary hip arthroplasties at a median follow-up of 47 months. Overall survival probability was 94.6% at 5 years and 81.8% at 9 years using survivorship analysis. Perioperative morbidity was minimal. Total hip arthroplasty using contemporary techniques and current management protocols can provide reliable functional improvement in patients with osteonecrosis secondary to SLE.

Disorders of hemoglobin synthesis affect the musculoskeletal system by either causing replacement of bone by hematopoietic tissue, precipitating bone and soft tissue ischemia and necrosis, or a combination of both processes. Less frequently, joints are involved by synovial ischemia, synovial deposition of iron, or microfracture of subchondral bone. Osteopenia is a significant problem in both thalassemia and sickle cell anemia and may result in vertebral and long bone fractures. Growth disturbances are frequently seen but are not often appreciated until adolescence because of improved hematologic management. The cause of the growth problems is multifactorial and may be related to hormonal deficiencies, iron overload, hypoxia, or local trauma to the growth plate secondary to significant osteopenia.

Femoral canal membrane tissue from patients who had revision of an uncemented endoprosthesis to a total hip replacement was analyzed and interlocking bone specimens were retrieved from implant fenestrations to compare membrane histology with microscopic bony remodelling. Radiographs of each hip were evaluated for bony adaptations and correlated with implant stability and interface histology. Uncemented canal membranes are composed mostly of mildly cellular dense connective tissue. Significant inflammation is rare, even in the presence of moderate metallic debris. A fibrocartilage interface often occurs above interlocking bone in areas subject to direct compressive loads. A thin membrane helps to distribute loads evenly from the rigid implant to more compliant bone. Dense lines of bone around the implant stem may be a biologic response indicating a steady-state, load-sharing equilibrium; they are not a reliable sign of implant instability. Retrieved interface membranes allow a direct view of the prosthetic-bone junction of human joint implants. In the absence of polyethylene and methacrylate wear debris, the membrane contains quiescent fibrous tissue with little inflammation. Membrane formation appears to be a mechanical adaptation to improve load distribution in the proximal femur. Presence and function of the membrane must be considered in the design and application of future press-fit implants.