Inserting a screw into a long bone introduces a stress riser that can predispose the bone to fracture. Where multiple screws are inserted this vulnerability may be increased. It is thought that the pattern of screw insertion plays an important part in determining the susceptibility of the bone to stress fracture. In order to study the importance of pattern of screw insertion, third generation composite femora with cannulated screws inserted in two different patterns were tested to failure by a servohydraulic materials test system. The vertical pattern of screw insertion is less apt to predispose a long bone to subsequent fracture than a horizontal pattern.

The purpose of this study was to evaluate any differences in the accuracy of knee MRI interpretation between radiology and orthopaedic surgery residents as well as to evaluate differences in quality of interpretation relative to resident training level. In this study, 20 MRI scans demonstrating specifc pathology of the knee were identifed. From one institution, two radiology residents and two orthopaedic surgery residents of each postgraduate year (PGY) of training (2 to 5) were recruited. Each resident was asked to interpret all the studies and choose up to 16 diagnoses for each scan from the list provided. Orthopaedic surgery residents showed improvement in overall accuracy and specifcity with each year of additional training. Level of training did not correspond with increased sensitivity in the orthopaedic residents tested. Radiology residents did not demonstrate a consistent trend toward improved accuracy, sensitivity, or specifcity with additional years of training. The only statistically signifcant differences in specifcity observed between the two groups were seen in the readings of ACL tears, lateral femoral condyle chondromalacia, and chondromalacia patella. This study found that the accuracy of knee MRI interpretations between radiology and orthopaedic surgery residents did not demonstrate any differences. Level of training had no effect on the interpretation of the MRIs by radiology residents. Orthopaedic surgery residents did show an improvement with each year of additional training.

Currently, intramedullary devices are widely used for the treatment of trochanteric femoral fractures. A new device designed by AO/ASIF, the PFNA (proximal femoral nail antirotation), represents a unique intramedullary nail system for improved management, particularly in the elderly. The aim of the present study was to analyze the results of treatment with PFNA in 50 patients with trochanteric fractures. The operating time, intraoperative blood loss, and intraoperative and postoperative complications were recorded. The length of the surgical procedure averaged 20.3 min, and intraoperative blood loss averaged 22.8 mL. Reoperation was necessary in two patients (4%). We conclude that the PFNA nail is as effective as other implants in the treatment of trochanteric fractures.

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A retrospective evaluation was done to determine the relationship between hospital volume and in-hospital mortality, complications, and length of stay in patients with operatively treated fractures of the pelvis or acetabulum. Patients were divided into three groups based on hospital volume. High volume centers had higher percentages of patients with one or more comorbidities, but who were less severely injured. Mortality rates were highest in small volume centers. Mod- erate volume centers had the lowest odds of death. Complication rates were similar between small and high volume hospitals. Length of stay was shortest in high volume centers. In-hospital outcomes associated with surgical fxation of the pelvis, acetabulum, or both were not uniformly associated with hospital volume.

Although air bags have been reported to reduce passenger mortality in frontal collisions, they have also beenreported as a cause of injury in motor vehicle collisions(MVCs). The purpose of this study was to evaluate a large cohort of patients involved in MVCs to determine mortality and the pattern of injuries associated with seat belt use and air bag deployment. Information on patients involved in MVCs from 1988 to 2004 was obtained from the National Trauma Data Bank (NTDB). The data was evaluated based on four groups of safety devices: seat belt and deployed air bag (SBAB), seat belt only (SBO), deployed air bag only (ABO), and no safety devices (None). A total of 35,333 patients met study inclusion criteria. Air bags and seat belts used in combination decreased the risk of potentially fatal injuries, but increased the risk of lower extremity injuries (odds ratio, 1.35). The use of any type of restraint led to a decrease in the risk of injury or mortality in MVCs. Only half of all individu- als in this study used any type of restraint device, which indicates the need for significant improvements in public health and safety seat belt utilization programs.

Anesthesia is a broad discipline; for orthopaedic applications, the type and location of the planned orthopaedic procedure is important in the selection of the most appropriate anesthetic agent and technique. The purpose of this overiew is to: 1. highlight the role of several anesthetic agents commonly used in an orthopaedic setting and 2. to familiarize the orthopaedist with those techniques of regional anesthesia that have implications for emergency rooms and other ambulatory settings. Because the subject matter is expansive in scope, it is necessary to address each of the above objectives separately, in two different articles. Part 1 describes anesthetic agents, whereas Part 2 encompases techniques of adminsistering regional anesthesia.

Anesthesia may be considered in terms of two categories: general and regional. The aim of general anesthesia is to induce analgesia, sedation, amnesia, suppression of autonomic reflexes, and relaxation of muscles. Regional anesthesia is more site-specific and is typically divided into three categories based on the location of injection: 1. a central neuraxial block is an injection of an anesthetic drug into the epidural or intrathecal space; 2. a periph- eral nerve block is an injection near the nerve or plexus supplying the area under operation; and 3. a field block is an injection into the adjoining tissues with subsequent diffusion into the surgical area (in orthopaedics, it is typically employed for minor procedures of the hand or foot). Of these three categories of regional anesthesia (i.e., neuraxial, peripheral, and field blocks), this article focuses on the latter two. Although neuraxial blocks comprise an important part of regional anesthesia, they are typically performed by anesthesiologists in an operative setting for major procedures of the lower extremities. The intent of this article is to familiarize the orthopaedist with techniques that have implications for emergency rooms and other ambulatory settings in which regional techniques are sometimes favored over general alternatives because they entail less risk of systemic side effects and may involve more cost-effective use of resources.

Distal locking is considered a diffcult stage of the endomedullary tibial nailing procedure. A new rapid, simple, and inexpensive freehand aiming technique is presented that uses a galvanized metal grid. The grid is positioned to overlay the skin of the medial cutaneous face of the tibia, giving to the underlying bone under fuoroscopy a pattern that resembles a chessboard. The squares of the grid permit a rapid and accurate localization of the corresponding distal holes of the endomedullary nail, requiring only a single fuoroscopy image, which can be important relative to radiation exposure.

Bilateral asymmetric dislocations of the hip are rare compared to unilateral dislocations. This case study describes a female restrained passenger involved in a motor vehicle accident who sustained asymmetric bilateral hip dislocations. The patient underwent successful closed reduction of both hips. The clinical course and follow-up assessment of the patient was otherwise uneventful. Computed tomography scans, essential for diagnosing intra-articular loose bodies and subtle fractures, were performed after reduction and revealed in the right hip a nondisplaced acetabular rim fracture of the posterior wall on the side of the posterior dislocation. Hip dislocations are an injury requiring careful trauma evaluation to rule out concomitant injuries. Time to presentation and, more importantly, reduction of a hip dislocation, is essential in treating this injury and preventing long-term complications, such as avascular necrosis and posttraumatic arthritis. The incidence, anatomy, mechanism of injury, treatment options, and long-term sequelae of hip dislocation, with literature review, are discussed.

Complete anaesthesia in the cutaneous distribution of the ulnar nerve following submuscular anterior transposition of the ulnar nerve has not been previously reported. We postulate vascular insult as the etiology of this conditionand suggest there may be clinical importance to preserving the ulnar nerve blood supply during submuscular anterior transposition.

Inserting a screw into a long bone introduces a stress riser that can predispose the bone to fracture. Where multiple screws are inserted this vulnerability may be increased. It is thought that the pattern of screw insertion plays an important part in determining the susceptibility of the bone to stress fracture. In order to study the importance of pattern of screw insertion, third generation composite femora with cannulated screws inserted in two different patterns were tested to failure by a servohydraulic materials test system. The vertical pattern of screw insertion is less apt to predispose a long bone to subsequent fracture than a horizontal pattern.

The purpose of this study was to evaluate any differences in the accuracy of knee MRI interpretation between radiology and orthopaedic surgery residents as well as to evaluate differences in quality of interpretation relative to resident training level. In this study, 20 MRI scans demonstrating specifc pathology of the knee were identifed. From one institution, two radiology residents and two orthopaedic surgery residents of each postgraduate year (PGY) of training (2 to 5) were recruited. Each resident was asked to interpret all the studies and choose up to 16 diagnoses for each scan from the list provided. Orthopaedic surgery residents showed improvement in overall accuracy and specifcity with each year of additional training. Level of training did not correspond with increased sensitivity in the orthopaedic residents tested. Radiology residents did not demonstrate a consistent trend toward improved accuracy, sensitivity, or specifcity with additional years of training. The only statistically signifcant differences in specifcity observed between the two groups were seen in the readings of ACL tears, lateral femoral condyle chondromalacia, and chondromalacia patella. This study found that the accuracy of knee MRI interpretations between radiology and orthopaedic surgery residents did not demonstrate any differences. Level of training had no effect on the interpretation of the MRIs by radiology residents. Orthopaedic surgery residents did show an improvement with each year of additional training.

Currently, intramedullary devices are widely used for the treatment of trochanteric femoral fractures. A new device designed by AO/ASIF, the PFNA (proximal femoral nail antirotation), represents a unique intramedullary nail system for improved management, particularly in the elderly. The aim of the present study was to analyze the results of treatment with PFNA in 50 patients with trochanteric fractures. The operating time, intraoperative blood loss, and intraoperative and postoperative complications were recorded. The length of the surgical procedure averaged 20.3 min, and intraoperative blood loss averaged 22.8 mL. Reoperation was necessary in two patients (4%). We conclude that the PFNA nail is as effective as other implants in the treatment of trochanteric fractures.

.

A retrospective evaluation was done to determine the relationship between hospital volume and in-hospital mortality, complications, and length of stay in patients with operatively treated fractures of the pelvis or acetabulum. Patients were divided into three groups based on hospital volume. High volume centers had higher percentages of patients with one or more comorbidities, but who were less severely injured. Mortality rates were highest in small volume centers. Mod- erate volume centers had the lowest odds of death. Complication rates were similar between small and high volume hospitals. Length of stay was shortest in high volume centers. In-hospital outcomes associated with surgical fxation of the pelvis, acetabulum, or both were not uniformly associated with hospital volume.

Although air bags have been reported to reduce passenger mortality in frontal collisions, they have also beenreported as a cause of injury in motor vehicle collisions(MVCs). The purpose of this study was to evaluate a large cohort of patients involved in MVCs to determine mortality and the pattern of injuries associated with seat belt use and air bag deployment. Information on patients involved in MVCs from 1988 to 2004 was obtained from the National Trauma Data Bank (NTDB). The data was evaluated based on four groups of safety devices: seat belt and deployed air bag (SBAB), seat belt only (SBO), deployed air bag only (ABO), and no safety devices (None). A total of 35,333 patients met study inclusion criteria. Air bags and seat belts used in combination decreased the risk of potentially fatal injuries, but increased the risk of lower extremity injuries (odds ratio, 1.35). The use of any type of restraint led to a decrease in the risk of injury or mortality in MVCs. Only half of all individu- als in this study used any type of restraint device, which indicates the need for significant improvements in public health and safety seat belt utilization programs.

Anesthesia is a broad discipline; for orthopaedic applications, the type and location of the planned orthopaedic procedure is important in the selection of the most appropriate anesthetic agent and technique. The purpose of this overiew is to: 1. highlight the role of several anesthetic agents commonly used in an orthopaedic setting and 2. to familiarize the orthopaedist with those techniques of regional anesthesia that have implications for emergency rooms and other ambulatory settings. Because the subject matter is expansive in scope, it is necessary to address each of the above objectives separately, in two different articles. Part 1 describes anesthetic agents, whereas Part 2 encompases techniques of adminsistering regional anesthesia.

Anesthesia may be considered in terms of two categories: general and regional. The aim of general anesthesia is to induce analgesia, sedation, amnesia, suppression of autonomic reflexes, and relaxation of muscles. Regional anesthesia is more site-specific and is typically divided into three categories based on the location of injection: 1. a central neuraxial block is an injection of an anesthetic drug into the epidural or intrathecal space; 2. a periph- eral nerve block is an injection near the nerve or plexus supplying the area under operation; and 3. a field block is an injection into the adjoining tissues with subsequent diffusion into the surgical area (in orthopaedics, it is typically employed for minor procedures of the hand or foot). Of these three categories of regional anesthesia (i.e., neuraxial, peripheral, and field blocks), this article focuses on the latter two. Although neuraxial blocks comprise an important part of regional anesthesia, they are typically performed by anesthesiologists in an operative setting for major procedures of the lower extremities. The intent of this article is to familiarize the orthopaedist with techniques that have implications for emergency rooms and other ambulatory settings in which regional techniques are sometimes favored over general alternatives because they entail less risk of systemic side effects and may involve more cost-effective use of resources.

Distal locking is considered a diffcult stage of the endomedullary tibial nailing procedure. A new rapid, simple, and inexpensive freehand aiming technique is presented that uses a galvanized metal grid. The grid is positioned to overlay the skin of the medial cutaneous face of the tibia, giving to the underlying bone under fuoroscopy a pattern that resembles a chessboard. The squares of the grid permit a rapid and accurate localization of the corresponding distal holes of the endomedullary nail, requiring only a single fuoroscopy image, which can be important relative to radiation exposure.

Bilateral asymmetric dislocations of the hip are rare compared to unilateral dislocations. This case study describes a female restrained passenger involved in a motor vehicle accident who sustained asymmetric bilateral hip dislocations. The patient underwent successful closed reduction of both hips. The clinical course and follow-up assessment of the patient was otherwise uneventful. Computed tomography scans, essential for diagnosing intra-articular loose bodies and subtle fractures, were performed after reduction and revealed in the right hip a nondisplaced acetabular rim fracture of the posterior wall on the side of the posterior dislocation. Hip dislocations are an injury requiring careful trauma evaluation to rule out concomitant injuries. Time to presentation and, more importantly, reduction of a hip dislocation, is essential in treating this injury and preventing long-term complications, such as avascular necrosis and posttraumatic arthritis. The incidence, anatomy, mechanism of injury, treatment options, and long-term sequelae of hip dislocation, with literature review, are discussed.

Complete anaesthesia in the cutaneous distribution of the ulnar nerve following submuscular anterior transposition of the ulnar nerve has not been previously reported. We postulate vascular insult as the etiology of this conditionand suggest there may be clinical importance to preserving the ulnar nerve blood supply during submuscular anterior transposition.