Showing papers in "Clinical Orthopaedics and Related Research in 2012"

The Chitranjan Ranawat award: is neutral mechanical alignment normal for all patients?: the concept of constitutional varus

Abstract: Background Most knee surgeons have believed during TKA neutral mechanical alignment should be restored. A number of patients may exist, however, for whom neutral mechanical alignment is abnormal. Patients with so-called “constitutional varus” knees have had varus alignment since they reached skeletal maturity. Restoring neutral alignment in these cases may in fact be abnormal and undesirable and would likely require some degree of medial soft tissue release to achieve neutral alignment.

The new Knee Society Knee Scoring System.

Abstract: In 1989, The Knee Society Clinical Rating System [3] was developed as a simple, but objective scoring system to rate the knee and patient’s functional abilities such as walking and stair climbing before and after TKA. Since the scoring system did not include assessment of radiographs, The Knee Society endorsed a method to evaluate radiographs [2]. The Knee Society Clinical Rating System has been the most popular method of tracking and reporting outcomes after total and partial knee arthroplasty worldwide. However, the reliability, responsiveness, and validity of the original score have been challenged. In addition, it became clear over time that there were ambiguities and deficiencies with the original Knee Society Clinical Rating System that challenged its utility and validity in our contemporary patients, who often have expectations, demands, and functional requirements that are different from those of prior generations of patients who underwent knee arthroplasty. The Knee Society therefore embarked on a complete review of the previous system. The project started more than 3 years ago and involved Knee Society members from 18 institutions in the United States and Canada; these individuals contributed more than 500 cases of both preoperative and postoperative TKA. The magnitude of this exhaustive project involved a multidisciplinary team of arthroplasty surgeons, epidemiologists, and statisticians. The prior objective knee score was amplified from the prior Knee Society score to incorporate current knee arthroplasty clinical parameters. The functional component of the new score was developed on the basis of comprehensive inventories of the activities and observations of 101 patients at five major knee arthroplasty centers who completed a 120-item survey, which was ultimately condensed down to the current assessment tool. This assessment tool was then included in the validation process at the 18 participating centers. The final scoring system was then approved by the Knee Society Scoring Committee. The new Knee Society Knee Scoring System is both physician and patient derived. It includes versions to be administered preoperatively (Appendix 1) and postoperatively (Appendix 2). It has an initial assessment of demographic details, including an expanded Charnley functional classification [1]. The objective knee score, completed by the surgeon, includes a VAS score of pain walking on level ground and on stairs or inclines, as well as an assessment of alignment, ligament stability, and ROM, along with deductions for flexion contracture or extensor lag. Patients then record their satisfaction, functional activities, and expectations. Given the diverse activity profiles of many contemporary patients, the functional component of the score was improved to include a patient-specific survey, which evaluates features such as standard activities of daily living, patient-specific sports and recreational activities, patient satisfaction, and patient expectations. Portions of the original Knee Society Clinical Rating System have been integrated into the new version to maintain the integrity of the prior version of the Knee Society score. The new Knee Society Knee Scoring System has been developed and validated, in part, to better characterize the expectations, satisfaction, and physical activities of the younger and more diverse population of current patients undergoing TKA. The new score provides sufficient flexibility and depth to capture the diverse lifestyles and activities of our current patients. The score was validated in a thoughtful and methodical fashion confirming internal reliability and analyzed for differential item functioning [4]. The new Knee Society Scoring System is broadly applicable across sex, age, activity level, and implant type. In conclusion, the new Knee Society Scoring System is a validated and responsive method for assessing objective and subjective outcomes after total and partial knee arthroplasty, without the ambiguities of the prior scoring system. As physicians, clinical practices, and health systems become increasingly more responsible for reporting patient outcomes, the clear value of this new scoring system will become apparent. The new scoring system is available through application on the Knee Society Web site (http://www.kneesociety.org).

Patient-related Risk Factors for Postoperative Mortality and Periprosthetic Joint Infection in Medicare Patients Undergoing TKA

Abstract: Background The impact of specific baseline comorbid conditions on the relative risk of postoperative mortality and periprosthetic joint infection (PJI) in elderly patients undergoing TKA has not been well defined.

Development of a new Knee Society scoring system

Abstract: Background The Knee Society Clinical Rating System was developed in 1989 and has been widely adopted. However, with the increased demand for TKA, there is a need for a new, validated scoring system to better characterize the expectations, satisfaction, and physical activities of the younger, more diverse population of TKA patients.

Most effective regimen of tranexamic acid in knee arthroplasty: a prospective randomized controlled study in 240 patients.

Abstract: Background The antifibrinolytic tranexamic acid reduces surgical blood loss, but studies have not identified an optimal regimen

Improved Accuracy of Alignment With Patient-specific Positioning Guides Compared With Manual Instrumentation in TKA

Abstract: Coronal malalignment occurs frequently in TKA and may affect implant durability and knee function. Designed to improve alignment accuracy and precision, the patient-specific positioning guide is predicated on restoration of the overall mechanical axis and is a multifaceted new tool in achieving traditional goals of TKA. We compared the effectiveness of patient-specific positioning guides to manual instrumentation with intramedullary femoral and extramedullary tibial guides in restoring the mechanical axis of the extremity and achieving neutral coronal alignment of the femoral and tibial components. We retrospectively reviewed 569 TKAs performed with patient-specific positioning guides and 155 with manual instrumentation by two surgeons using postoperative long-leg radiographs. For all patients, we assessed the zone in which the overall mechanical axis passed through the knee, and for one surgeon’s cases (105 patient-specific positioning guide, 55 manual instrumentation), we also measured the hip-knee-ankle angle and the individual component angles with respect to their mechanical axes. The overall mechanical axis passed through the central third of the knee more often with patient-specific positioning guides (88%) than with manual instrumentation (78%). The overall mean hip-knee-ankle angle for patient-specific positioning guides (180.6°) was similar to manual instrumentation (181.1°), but there were fewer ± 3° hip-knee-ankle angle outliers with patient-specific positioning guides (9%) than with manual instrumentation (22%). The overall mean tibial (89.9° versus 90.4°) and femoral (90.7° versus 91.3°) component angles were closer to neutral with patient-specific positioning guides than with manual instrumentation, but the rate of ± 2° outliers was similar for both the tibia (10% versus 7%) and femur (22% versus 18%). Patient-specific positioning guides can assist in achieving a neutral mechanical axis with reduction in outliers. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Robotic-assisted TKA Reduces Postoperative Alignment Outliers and Improves Gap Balance Compared to Conventional TKA

Abstract: Background Several studies have shown mechanical alignment influences the outcome of TKA. Robotic systems have been developed to improve the precision and accuracy of achieving component position and mechanical alignment.

Reliability of a Complication Classification System for Orthopaedic Surgery

Abstract: Background Quality of health care and safety have been emphasized by various professional and governmental groups. However, no standardized method exists for grading and reporting complications in orthopaedic surgery. Conclusions regarding outcomes are incomplete without a standardized, objective complication grading scheme applied concurrently. The general surgery literature has the Clavien-Dindo classification that meets the above criteria.

Do Patient-specific Guides Improve Coronal Alignment in Total Knee Arthroplasty?

Abstract: Background Coronal alignment may impact clinical outcome and survivorship in TKA. Patient-specific instrumentation has been developed to restore mechanical or kinematic axis and potentially reduce component malpositioning. Although it is clear these instruments add cost, it is unclear whether they improve alignment.

Unicompartmental versus total knee arthroplasty database analysis: is there a winner?

Abstract: Background TKA and unicompartmental knee arthroplasty (UKA) are both utilized to treat unicompartmental knee arthrosis. While some surgeons assume UKA provides better function than TKA, this assumption is based on greater final outcome scores rather than on change in scores and many patients with UKA have higher preoperative scores.

Are patient-specific cutting blocks cost-effective for total knee arthroplasty?

Abstract: Background Using patient-specific cutting blocks for TKA increases the cost to the hospital for these procedures, but it has been proposed they may reduce operative times and improve implant alignment, which could reduce the need for revision surgery.

Gustilo-Anderson Classification

Abstract: Open fractures usually are high-energy injuries. This, along with the exposure of bone and deep tissue to the environment, leads to increased risk of infection, wound complications, and nonunion [12, 28, 31]. Antibiotics, surgical débridement, and internal fixation have improved outcomes of open fracture management in important ways, but the underlying principles for treating open fractures have remained the same since World War I: primary asepsis, adequate debridement, immobilization, and protection of wounds against disturbance and reinfection [25, 26]. Despite the overall improvement in outcome after open fractures, the variable outcomes among different patterns of open fractures with differing severities prompted the development of grading systems that classify them based on increasing severity of the associated soft tissue injuries. These grading systems seek to help guide treatment, improve communication and research, and predict outcome. Such classifications have been in use for some time [29]; however, it is the Gustilo-Anderson classification that has become the most commonly used system for classifying open fractures. Early attempts by Veliskakis [29] at grading open fractures were refined by Gustilo and Anderson in 1976 [16]. After reviewing their initial classification of the most severe open injuries, Gustilo et al. subsequently modified their classification system into its current form in 1984 [17]. Ultimately, through their studies of prevention of infection in open long bone fractures [16, 17], Gustilo et al. outlined the general principles of management of open fractures, and helped define the contemporary approach to the treatment of open fractures.

Three-dimensional Morphology of the Knee Reveals Ethnic Differences

Abstract: Background Studies have demonstrated sex differences in femoral shape and quadriceps angle raising a question of whether implant design should be sex-specific. Much of this research has addressed shape differences within the Caucasian population and little is known about differences among ethnic groups.

Pelvic Discontinuity Treated With Custom Triflange Component: A Reliable Option

Abstract: Background Pelvic discontinuity is an increasingly common complication of THA. Treatments of this complex situation are varied, including cup-cage constructs, acetabular allografts with plating, pelvic distraction technique, and custom triflange acetabular components. It is unclear whether any of these offer substantial advantages.

Surgical Technique: Development of an Anatomic Medial Knee Reconstruction

Abstract: Background The main static stabilizers of the medial knee are the superficial medial collateral and posterior oblique ligaments. A number of reconstructive techniques have been advocated including one we describe here. However, whether these reconstructions restore function and stability is unclear.

The Frank Stinchfield Award: Dislocation in revision THA: do large heads (36 and 40 mm) result in reduced dislocation rates in a randomized clinical trial?

Abstract: Background Dislocation after revision THA is a common complication. Large heads have the potential to decrease dislocation rate, but it is unclear whether they do so in revision THA.

A Short Tapered Stem Reduces Intraoperative Complications in Primary Total Hip Arthroplasty

Abstract: Background While short-stem design is not a new concept, interest has surged with increasing utilization of less invasive techniques. Short stems are easier to insert through small incisions. Reliable long-term results including functional improvement, pain relief, and implant survival have been reported with standard tapered stems, but will a short taper perform as well?

Pseudotumors Are Common in Well-positioned Low-wearing Metal-on-Metal Hips

Abstract: Background Pseudotumors are sterile inflammatory lesions found in the soft tissues surrounding metal-on-metal (MOM) and metal-on-polyethylene hip arthroplasties. In patients with MOM hip arthroplasties, pseudotumors are thought to represent an adverse reaction to metal wear debris. However, the pathogenesis of these lesions remains unclear. Currently, there is inconsistent evidence regarding the influence of adverse cup position and increased wear in the formation of pseudotumors.

Hemiarthroplasty for Humeral Four-part Fractures for Patients 65 Years and Older: A Randomized Controlled Trial

Abstract: Background Four-part fractures of the proximal humerus account for 3% of all humeral fractures and are regarded as the most difficult fractures to treat in the elderly. Various authors recommend nonoperative treatment or hemiarthroplasty, but the literature is unclear regarding which provides better quality of life and function.

Preoperative anemia in total joint arthroplasty: is it associated with periprosthetic joint infection?

Abstract: Anemia is common in patients undergoing total joint arthroplasty (TJA). Numerous studies have associated anemia with increased risk of infection, length of hospital stay, and mortality in surgical populations. However, it is unclear whether and to what degree preoperative anemia in patients undergoing TJA influences postoperative periprosthetic joint infection (PJI) and mortality. We therefore (1) determined the incidence of preoperative anemia in patients undergoing TJA; (2) assessed the possible association between preoperative anemia and subsequent PJI; and (3) explored the relationship between preoperative anemia with postoperative mortality. We identified 15,722 patients who underwent TJA from January 2000 to June 2007. Anemia was defined as hemoglobin < 12 g/dL in women and hemoglobin < 13 g/dL in men. We determined the effect of preoperative anemia, demographics, and comorbidities on postoperative complications. Of the 15,222 patients, 19.6% presented with preoperative anemia. PJI occurred more frequently in anemic patients at an incidence of 4.3% in anemic patients compared with 2% in nonanemic patients. Thirty-day (0.4%), 90-day (0.6%), and 1-year (1.8%) mortality rates were not higher in patients with preoperative anemia. Forty-four percent of anemic patients received an allogenic transfusion compared with only 13.4% of nonanemic patients. Anemic patients had increased hospital stays averaging 4.3 days compared with 3.9 days in nonanemic patients. Anemia did not predict cardiac complications. Our data demonstrate that preoperative anemia is associated with development of subsequent PJI. Preoperative anemia was not associated with 30-day, 60-day, or 1-year mortality in this cohort. Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Corrosion at the Cone/Taper Interface Leads to Failure of Large-diameter Metal-on-metal Total Hip Arthroplasties

Abstract: Background Metal-on-metal (MoM) THAs have reduced wear rates compared with metal-on-polyethylene. However, elevated serum metal ion levels and pseudotumors have been reported in large MoM articulations.

Total Hip Arthroplasty Versus Hemiarthroplasty for Displaced Femoral Neck Fractures: Meta-analysis of Randomized Trials

Abstract: Background Most patients with displaced femoral neck fractures are treated by THA and hemiarthroplasty, but it remains uncertain which if either is associated with better function and lower risks of complications.

Operating room traffic is a major concern during total joint arthroplasty.

Abstract: Background Periprosthetic joint infection (PJI) is a challenging complication associated with total joint arthroplasty (TJA). Traffic in the operating room (OR) increases bacterial counts in the OR, and may lead to increased rates of infection.

Endoprostheses last longer than intramedullary devices in proximal femur metastases.

Abstract: Background The proximal femur is the most common site of surgery for bone metastases, and stabilization may be achieved through intramedullary fixation (IMN) or endoprosthetic reconstruction (EPR). Intramedullary devices are less expensive, less invasive, and may yield improved function over endoprostheses. However, it is unclear which, if either, has any advantages.

Incidence of Patients with Lower Extremity Injuries Presenting to US Emergency Departments by Anatomic Region, Disease Category, and Age

Abstract: The incidence of patients with lower extremity injuries presenting to emergency departments in the United States with respect to specific anatomic regions and disease categories is unknown Such information might be used for injury prevention, resource allocation, and training priorities We determined the anatomic regions, disease categories, and circumstances that account for the highest incidence of leg problems among patients presenting to emergency departments in the United States We used the National Electronic Injury Surveillance System (NEISS) to obtain a probability sample of all lower extremity injuries treated at emergency departments during 2009 A total of 119,815 patients who presented to emergency departments with lower extremity injuries in 2009 were entered in the NEISS database Patient and injury characteristics were analyzed Incidence rates for various regions, disease categories, injuries, and age groups were calculated using US census data We identified 112 unique combinations of disease categories and anatomic regions Strains and sprains accounted for 36% of all lower extremity injuries The injury with the greatest incidence was an ankle sprain (206 per 100,000; 95% confidence interval, 181–230) Younger patients were more likely to have ankle sprains, foot contusions/abrasions, and foot strains/sprains Older patients were more likely to have lower trunk fractures and lower trunk contusions/abrasions The most common incidence for injury was at home (45%) Given relatively low-acuity leg problems such as strains and sprains account for a substantial number of emergency department visits pertaining to leg problems, use of telephone triage, scheduled same or next-day urgent care appointments, and other alternatives to the traditional emergency room might result in better use of emergency healthcare resources

Combined anterior-posterior surgery is the most important risk factor for developing proximal junctional kyphosis in idiopathic scoliosis.

Abstract: Background Several studies have identified risk factors for proximal junctional kyphosis (PJK) after instrumentation for scoliosis, but the relative risks are unclear.

Nonoperative versus Operative Treatment for Thoracolumbar Burst Fractures Without Neurologic Deficit: A Meta-analysis

Abstract: Background Decision-making regarding nonoperative versus operative treatment of patients with thoracolumbar burst fractures in the absence of neurologic deficits is controversial. Lack of evidence-based practice may result in patients being treated inappropriately and being exposed to unnecessary adverse consequences.

Proximal Component Modularity in THA—At What Cost?: An Implant Retrieval Study

Abstract: Background While modular femoral heads have been used in THA for decades, a recent innovation is a second neck-stem taper junction. Clinical advantages include intraoperative adjustment of leg length, femoral anteversion, and easier revision, all providing flexibility to the surgeon; however, there have been reports of catastrophic fracture, cold welding, and corrosion and fretting of the modular junction.

What Factors Predict Failure 4 to 12 Years After Periacetabular Osteotomy

Abstract: Background The goal of periacetabular osteotomy (PAO) is to delay or prevent osteoarthritic development in dysplastic hips. However, it is unclear whether the surgical goals are achieved and if so in which patients. This information is essential to select appropriate patients for a durable PAO that achieves its goals.

Complications of Anterior Subcutaneous Internal Fixation for Unstable Pelvis Fractures: A Multicenter Study

Abstract: Background Stabilization after a pelvic fracture can be accomplished with an anterior external fixator. These devices are uncomfortable for patients and are at risk for infection and loosening, especially in obese patients. As an alternative, we recently developed an anterior subcutaneous pelvic internal fixation technique (ASPIF).