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Objectives: This study examined factors influencing return to work (RTW) following severe fracture to a lower extremity., Methods: This prospective cohort study followed 312 individuals treated for a lower extremity fracture at 3 level-1 trauma centers. Kaplan-Meier estimates of the proportion of RTW were computed, and a Cox proportional hazards model was used to examine the contribution of multiple risk factors on RTW., Results: Cumulative proportions of RTW at 3, 6, 9, and 12 months post-injury were 0.26, 0.49, 0.60, and 0.72. After accounting for the extent of impairment, characteristics of the patient that correlated with higher rates of RTW included younger age, higher education, higher income, the presence of strong social support, and employment in a white-collar job that was not physically demanding. Receipt of disability compensation had a strong negative effect on RTW., Conclusions: Despite relatively high rates of recovery, one quarter of persons with lower extremity fractures did not return to work by the end of 1 year. The analysis points to subgroups of individuals who are at high risk of delayed RTW, with implications for interventions at the patient, employer, and policy levels.

We performed a prospective study of 302 patients who had a fracture of the lower extremity. Our purpose was to determine whether there was any association between impairment ratings of the lower extremity, derived with use of the Guides to the Evaluation of Permanent Impairment by the American Medical Association, and measurements of task performance based on direct observation as well as the patient's own assessment of activity limitation and disability as recorded on the Sickness Impact Profile. The mean residual impairment of the lower extremity according to the Guides was 27 per cent one year after the injury. Only 130 subjects (43 per cent) could perform all five functional tasks without difficulty. Eighty-four subjects (28 per cent) reported functional limitations that resulted in a score on the Sickness Impact Profile that was more than one standard deviation from the preinjury norm for the sample. Impairment ratings according to a modification of the system of the American Medical Association correlated strongly with the performance of functional tasks (r = 0.57) as well as the patients' reported activity limitations as recorded on the Sickness Impact Profile (r = 0.55). Correlations were highest when measures of impairment were based on strength rather than on range of motion. The relationship between the impairment rating and function (as observed by an examiner and as reported by the patient) was not influenced by the location of the fracture or the receipt of disability compensation. Our results suggest that the American Medical Association developed a valid approach for the measurement of physical impairment after a fracture of the lower extremity. In our study, the anatomical approach of evaluation based on muscle strength that was described in the Guides to the Evaluation of Permanent Impairment was the most sensitive measure of impairment compared with the anatomical measure based on range of motion and compared with the functional and diagnostic methods for the rating of impairment. Until the diagnostic and functional approaches for the measurement of musculoskeletal impairment are refined, we recommend use of the anatomical approach when evaluating impairment after a fracture of the lower extremity.

Bone quality, initial fracture displacement, severity of fracture comminution, accuracy of fracture reduction, and the placement of the internal fixation device are important factors that affect fixation stability. New high strength cements that are susceptible to remodeling and replacement for fracture fixation may lead to improved clinical outcome in the treatment of hip fractures. Norian SRS is an injectable, fast setting cement that cures in vivo to form an osteoconductive carbonated apatite of high compressive strength (55 MPa) with chemical and physical characteristics similar to the mineral phase of bone. It can be used as a space filling internal fixation device to facilitate the geometric reconstruction, load transfer, and healing of bone with defects and/or fractures in regions of cancellous bone. Furthermore, this cement can improve the mechanical holding strength of conventional fixation devices. Use of this material potentially could improve fracture stability, retain anatomy during fracture healing and improve hip function, thus achieving better clinical outcomes. In vivo animal studies have shown the material's biocompatibility, and cadaveric studies have shown the biomechanical advantage of its use in hip fractures. Initial clinical experience (in 52 femoral neck fractures and 39 intertrochanteric fractures) showed the potential clinical use of this innovative cement in the treatment of hip fractures.

Certain supracondylar femoral fractures are not amenable to internal fixation with fixed angle devices. In these instances, the condylar buttress plate is the recommended alternative; however, this is a less rigid device. Because of the decreased rigidity and strength of this device, there is a tendency toward varus angulation and malunion. In six fresh-frozen human knee specimens, segmental osteotomies were created to mimic supracondylar femoral fractures. The medial cortex was completely removed to make the fracture unstable to varus deformity. The fracture was fixed with a lateral condylar buttress plate using 4.5 mm screws. Each specimen was tested once with all the screws installed perpendicular to the plate, and again with the middle screw, just proximal to the fracture, angled 45 degrees diagonally across the fracture into the subchondral bone of the medial femoral condyle. For the construct with all screws placed perpendicular to the buttress plate, the initial stiffness was 410 N/mm, and after 1000 cycles it was 230 N/mm. With a screw placed diagonally across the fracture site, stiffness increased to 833 N/mm on the first cycle, and 796 N/mm after 1000 cycles. In all specimens with the screws placed perpendicular to the plate, the distal fragment had a permanent varus deformity after 1000 cycles, under no load, of 0.91 mm. For the diagonal screw condition, the average magnitude for all six specimens was 0.42 mm. This simple means of screw angulation in the plate strengthened the overall construct to resist the tendency toward varus deformity. The attractive features include the ease of application, and the use of an existing construct.

We reviewed the literature to determine the clinical outcomes of the treatment of closed fractures of the tibial shaft with immobilization in a cast, open reduction with internal fixation, or fixation with an intramedullary rod. We reviewed 2372 reports of comparative trials and uncontrolled studies of series of patients published between 1966 and 1993. Nineteen reports, involving six controlled trials and twenty-seven groups of patients, met our inclusion criteria. A structured questionnaire was used to assess the quality of the literature in terms of the experimental design and the method of assessment of outcome. Outcomes from controlled trials were summarized with odds ratios and risk differences, and outcomes from case series were summarized by the medians of the reported results. The studies that were reviewed generally had few subjects and were poorly designed. The comparative trials showed treatment with a cast to be associated with a lower rate of superficial infection than open reduction and internal fixation (mean difference, -5.81 per cent; p = 0.02) and open reduction and internal fixation to be associated with a higher rate of union by twenty weeks than treatment with a cast (mean difference, -18.07 per cent; p = 0.008). There were no other significant associations. There were insufficient data for us to evaluate any aspect of functional status, level of pain, or other patient-reported outcomes of any of the methods of treatment. The results of the present review suggest that the data from the published literature are inadequate for decision-making with regard to the treatment of closed fractures of the tibia.

The clinical and functional outcomes for patients treated with open reduction and plate fixation of displaced tibial pilon fractures were determined. A retrospective search of the authors' trauma database was conducted for AO and Orthopaedic Trauma Association Code 43 injuries (pilon fractures) in adults 18 years or older who were treated between December 1988 and December 1992. The group of 64 patients who required open reduction and internal fixation to treat their fractures make up the primary cohort for this analysis. Twenty of these cases required no fibular fixation; the remainder were mostly fixed with 1/3 tubular or 3.5-mm compression plates. Tibial fixation was done using most commonly 3.5-mm cloverleaf plates, 1/3 tubular plates, or both. Of the 64 patients treated with open reduction and internal replacement, four (5%) patients had deep infection develop. Two (7%) of 14 patients had open fractures, and two (4%) of 50 patients had closed fractures. Three of these four patients smoked tobacco products; one was also an intravenous drug abuser. Staphylococcus aureus was the organism in two cases; Enterobacter, in the other two. The infection was controlled with a free flap in two cases, with antibiotics and wound debridement in one and with an arthrodesis in one. Thirty of the 64 patients completed the Short Form-36; two of these patients had bilateral fractures. The study group had significant differences in general health perceptions, physical function, physical role function, emotional role function, social and mental function, and pain and energy levels when compared with age matched population data and patients with tibial plateau fractures. The effect of other injuries on these functional status results cannot be determined specifically.

Objective: To compare unreamed intramedullary nailing (IMN) with external fixation (EF) in patients with Type II, IIIA, and IIIB open fractures of the tibial shaft., Design: An inception cohort of consecutive patients with Type II, IIIA, and IIIB tibial fractures incurred between January 1988 and March 1993 were systematically allocated into one of two treatment groups. Patients were treated and followed with a prospectively designed protocol., Patients and Setting: All patients were skeletally mature and had incurred a fracture of the tibial diaphysis within twenty-four hours of presentation to the tertiary care hospital, a Level I Trauma Center. One hundred seventy-four fractures in 168 patients were stabilized with either IMN (104) or half-pin EF (70). There were 132 men and thirty-six women, with an average age of thirty-three years (range, 14 to 77 years)., Intervention: Except for the selection of the fixation device, open fracture care was similar in the two treatment groups. All patients underwent emergent irrigation and debridement with concomitant skeletal stabilization. Cephalosporin antibiotics were administered perioperatively for twenty-four to forty-eight hours. No wounds were closed primarily. Delayed primary closure, skin grafting, and/or myoplasty were performed between three and ten days after injury., Main Outcome Measures: The main outcome measures were final fracture alignment, presence of infection or inflammation, hardware failure, time to union, and the number of operative procedures., Results: The IMN group had significantly fewer incidences of malalignment than did the EF group [8 vs. 31 percent; p = 0.00005; confidence interval (CI) = 0.18, 0.76] and had significantly fewer subsequent procedures (mean of 1.7 vs. mean of 2.7 per fracture; p = 0.001; CI = 0.45, 1.59). IMN resulted in fewer infections/ inflammatory problems than did EF at the injury site (13 vs. 21 percent; p = 0.73; CI = -0.63, 0.45) and significantly fewer at surgical interfaces (i.e., pin sites, nail and interlocking screw insertion sites; 2 vs. 50 percent; p = 0.000; CI = 0.39, 0.60). No significant difference was found in the healing rates for the two implant groups. The more severe Gustilo injury types had longer healing times regardless of the type of fixation., Conclusions: Results suggest that unreamed interlocking intramedullary nails are more efficacious than half-pin external fixators, in particular with regard to maintenance of limb alignment. However, the severity of soft tissue injury rather than the choice of implant appears to be the predominant factor influencing rapidity of bone healing and rate of injury site infection.

Objectives: To evaluate the interobserver variation for the AO/OTA fracture classification system: region forty-three-pilon fractures., Methods: One senior attending, two fellows (one trauma, one foot and ankle), one junior orthopaedic resident, and one experienced research coordinator independently classified eighty-four sets of radiographs. The evaluator was blinded as to treatment and functional outcome. The radiographs initially used to manage the patients were evaluated; no special radiographs or standardized radiographic techniques were used. The kappa statistic, Williams index, and SAV statistic were calculated., Results: Using the SAV statistic to quantify rater agreement beyond that expected by chance alone, the average chance-adjusted agreement among the raters was 0.57 for fracture type, 0.43 for group, and 0.41 for subgroup. This is equivalent to moderate agreement (0.41 to 0.60). The kappa statistic was used to determine whether there was difficulty with any specific category of the AO type classification among raters for selecting fracture type (A, B, C). Kappa values were 0.49 for type A, 0.58 for type B, 0.57 for type C, all of which were considered adequate., Conclusion: These data are similar to others reported for interobserver agreement with the AO/OTA fracture classification and other classification systems. The issue of individual judgement in taking a continuous variable (fracture pattern) and compartmentalizing it into a dichotomous variable (fracture classification system) is highlighted by these data. Determination of fracture types alone (type A, B, or C) would seem to be sufficient for clinical research where fracture severity should be reported as a variable.

We compared the reliability, validity, and responsiveness of the Musculoskeletal Function Assessment (MFA) questionnaire with those of three commonly used health-status measures: the Short Form-36 (SF-36), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Sickness Impact Profile (SIP). The MFA, like the other health-status measures, demonstrated good reliability (intraclass correlation coefficients of more than 0.70), good sensitivity and specificity (more than 70 per cent), good criterion validity that correlated with physicians' ratings (p < 0.01), and good construct validity that correlated with the characteristics of the patients (p < 0.01). It also demonstrated better content validity than the other questionnaires, with no ceiling or floor effects for the total score. In addition, it was more responsive than the SF-36; for eight of the eleven comparisons, it was more efficient (relative efficiency of more than 2.00) in measuring changes in function between the baseline values and the values determined at the latest follow-up evaluation. These findings suggest that the MFA can be used to assess the health status of patients who have a musculoskeletal disorder.

Pelvic ring disruptions are challenging management problems for the orthopedic surgeon. Early hemorrhage, permanent nerve injury, and late pain caused by residual pelvic deformity are some of the many complicating factors. A variety of treatment alternatives are available to stabilize the disrupted pelvic ring. Each technique has inherent advantages and problems.

Since the late 1970's, an empirical relationship between the volume of procedures performed by a provider (a hospital or surgeon) and the outcome has been documented for various operations. The present study examines the relationship between the volume of hip replacements performed by surgeons and hospitals and the postoperative rate of complications. A statewide hospital discharge registry was used to identify patients who had had an elective hip replacement between 1988 and 1991. Patients who had had a revision procedure, who had been referred on an emergency basis, or who had had a diagnosis of a fracture or a malignant tumor on admission were excluded. There were 7936 eligible patients who had had 8774 hip replacements. The average annual number of all hip replacements performed from 1987 through 1991 was subsequently determined for each hospital and surgeon who had cared for at least one patient in the study cohort. The rate of operative complications was modeled as a function of the volume of procedures performed by the surgeon or hospital (the surgeon or hospital volume), with adjustment for the age of the patient, gender, co-morbidity, and operative diagnosis. We noted significant differences in the case mix of low-volume providers compared with that of high-volume providers (p < 0.01). In general, surgeons and hospitals with a volume below the fortieth percentile managed patients who had a more adverse risk profile in terms of age, co-morbidity, and diagnosis. Even after adjustment for the case mix, there was a significant relationship between surgeons who averaged fewer than two hip replacements annually (low-volume surgeons) and a worse outcome (p < 0.05). Patients managed by these low-volume surgeons tended to have higher mortality rates, more infections, higher rates of revision operations, and more serious complications during the index hospitalization. The duration of hospitalization was inversely related to surgeon volume and directly associated with hospital volume. Hospital charges were inversely related to hospital volume, even after adjustment for patient-related factors as well as the duration of hospitalization, the year of the operation, and the destination after discharge (p < 0.05). More detailed information is required to investigate the reason for these observed variations in the rates of complications. If future studies confirm an association between low-volume providers and an adverse outcome, performance of some types of elective total hip replacements at regional centers should be considered.

We sought to quantify agreement by different assessors of the AO classification for distal fractures of the radius. Thirty radiographs of acute distal radial fractures were evaluated by 36 assessors of varying clinical experience. Our findings suggest that AO 'type' and the presence or absence of articular displacement are measured with high consistency when classification of distal radial fractures is undertaken by experienced observers. Assessors at all experience levels had difficulty agreeing on AO 'group' and especially AO 'subgroup'. To categorize distal radial fractures according to joint displacement and AO type is simple and reproducible. Our study examined only whether distal radial fractures could be consistently classified according to the AO system. Validation of the classification as a predictor of outcome will require a prospective clinical study.

The first goal of this study was to determine if augmentation with an injectable, in situ setting, calcium-phosphate cement that is capable of being remodeled and was designed to mimic bone mineral significantly improved the strength and stiffness of fixation in a cadaveric femoral neck fracture model. The second goal was to determine if greater increases in fixation strength were achieved as the bone density of the specimen decreased. Sixteen pairs of fresh cadaveric human femora with a mean age of 70.9 years (SD = 17.2 years) were utilized. The bone density of the femoral neck was measured with dual-energy x-ray absorptiometry. The femoral head was impacted vertically with the femoral shaft fixed in 12 degrees of adduction using a materials testing machine to create a fully displaced fracture. Following fracture, 30% inferior comminution was created in each specimen. One randomly chosen femur from each pair underwent anatomic reduction and fixation with three cannulated cancellous bone screws, 7 mm in diameter, in an inverted triangle configuration. The contralateral femur underwent the same fixation augmented with calcium-phosphate cement. Specimens were preconditioned followed by 1.000 cycles to one body weight (611.6 N) at 0.5 Hz to simulate single-limb stance loading. The stiffness in the first cycle was observed to be significantly greater in cement-augmented specimens compared with unaugmented controls (p < 0.05). After cycling, each specimen was loaded at 10 mm/min until complete displacement of the fracture surface and failure of fixation occurred. Specimens augmented with bone mineral cement failed at a mean of 4,573 N (SD = 1,243 N); this was significantly greater (p < 0.01) than the mean for controls (3,092 N, SD = 1,258 N). The relative improvement in fixation strength (augmented/control x 100%) was not inversely correlated to femoral neck bone density (p = 0.25, R2 = 0.09), was weakly correlated to the volume of cement injected (p = 0.07, R2 = 0.22), and was inversely related to the fixation failure load of the control specimen (p = 0.001, R2 = 0.54). There was a mean relative improvement in fixation strength of 169.6% (SD = 77.5). These findings suggest that calcium-phosphate cement provides initial beneficial augmentation to fixation of femoral neck fractures.

The goals of internal fixation are an accurate reduction and stable fixation in the presence of adequate bony vascularity. This can be achieved by a variety of means including plate fixation. A certain amount of periosteal stripping is necessary for proper open reduction of a fracture and for proper plate application. With displaced diaphyseal fractures, cortical bone perfusion (CBP) is already compromised. Further damage, in terms of periosteal stripping for plate fixation, may not be acceptable. Little information is available as to what extent the periosteum contributes to cortical bone perfusion. The purpose of this study was to determine the acute effects of periosteal stripping on cortical bone perfusion in a sheep tibia model. Twenty-three sheep were operated on and had the medial aspect of their right tibia exposed. Cortical bone perfusion measurements were obtained using laser Doppler flowmetry prior to periosteal stripping and after periosteal stripping. The results of this study show that the cortical bone perfusion significantly decreased by 20% after periosteal stripping over the entire length of the tibia. We therefore conclude that the periosteum contributes to diaphyseal bone perfusion and that it is important to preserve this source with fractures where blood supply is already significantly compromised.

We used a miniature swine femoral neck fracture model to demonstrate the effects of the fracture on blood flow, histologic appearance, MRI signal and the development of posttraumatic osteonecrosis. The fracture was created and internally fixed in the right hip of 11 swine, with the left hip serving as the control. Femoral head blood flow via Laser Doppler Flowmetry and MRI data was examined for the experimental hip preoperatively, postoperatively and at 1, 2, 4 and 8 weeks postfracture. At 8 weeks, the animals were killed and the femoral heads were evaluated. Femoral head blood flow decreased immediately postfracture and continued to diminish with time. MRI signal intensities in the femoral head at 4 and 8 weeks were significantly less when the fixation failed than when it was intact. Histologic grades (0-14 points) and bone densities were 7.6 and 49%, respectively, on the experimental side, compared to 1.6 and 56% on the control side. Histologic grading, bone density values and blood flow data had no relation to changes in MRI signal intensity.

The Musculoskeletal Function Assessment (MFA) instrument, a health status instrument with 100 self-reported health items, was designed for use with the broad range of patients with musculoskeletal disorders of the extremities commonly seen in clinical practice. In this paper, we report on its criterion and construct validity. Criterion validity was tested against physicians' ratings of patient functioning (e.g., upper functioning, lower functioning, daily activities, recreational functioning, emotional adjustment, and overall functioning) and standard clinical measures (e.g., grip strength, walking speed, fine motor skills, knee and elbow strength, and range of motion). Significant correlations (p < or = 0.05) between its scores, physicians' ratings, and clinical measures support the MFA's criterion validity. Construct validity was demonstrated against existing measures of health status (e.g., measures of lower and upper mobility, activity level and satisfaction, health status, social support, pain, emotional status, and quality of life), in accordance with clinical hypotheses about the effect of musculoskeletal disorders on functioning (e.g., type and number of problems, severity of illness or injury, and comorbidities) and by an analysis of demographic characteristics (e.g., sex, education, income, health insurance, and employment) against the MFA scores. Discriminant construct validity was supported in an analysis of MFA scores by patient disease groups (p < or = 0.01).

Despite an increasing reliance on the use of health status measures to assess and evaluate medical care, no single instrument is currently available for use with the broad range of patients with musculoskeletal disorders of the extremities that is commonly seen in clinical practice. In this paper, we report on the development of the Musculoskeletal Function Assessment instrument, a 100-item self reported health status instrument that is designed to meet this need. The instrument was developed in two phases. During the first phase, items were selected on the basis of interviews with 135 patients and 12 clinicians and from reviews of existing health status instruments. The items then were grouped into categories. During the second phase, the instrument was tested for reliability and content validity using a sample of 327 patients with one of five musculoskeletal disorders of the upper and lower extremities (fractures, soft-tissue injuries, repetitive motion disorders, osteoarthritis, and rheumatoid arthritis). The patients were selected from both community and academic sites. Content validity also was demonstrated, based on a review of item selection procedures, expert opinion, and the distribution of scores on the instrument.

A study was performed to compare the effects of reamed versus unreamed locked intramedullary nailing on soft-tissue blood flow in a fractured sheep tibia model. After creation of a standardized short spiral fracture, each tibia was stabilized by insertion of a locked intramedullary nail. Ten animals were randomized into two groups: one that had reaming prior to nail insertion and one that did not. Blood flow was measured in real time, using laser Doppler flowmetry. Skin and muscle perfusion measurements were made at three locations (proximal diaphysis, fracture site, and distal diaphysis) and at five time intervals (postfracture; postnail insertion; and at 2-week, 6-week, and 12-week follow-ups). All animals were sacrificed at 12 weeks postoperatively. Muscle blood flow remained elevated longer in the reamed group than in the unreamed group, following completion of the procedure. Muscle perfusion was significantly greater in the reamed group than in the unreamed group (p < 0.033) and was significantly greater than skin perfusion at 2 weeks (p < 0.024). There was no difference in skin perfusion between the reamed and unreamed groups at any time interval. The study demonstrates that muscle perfusion is altered following reamed and unreamed intramedullary nailing. The findings demonstrate the change in blood flow in the surrounding soft-tissue envelope during the process of revascularization, following devascularization of a segment of tibial cortex by intramedullary nailing.

In order to understand the effect of malunion on functional outcome, it is essential that deformity be measured in a consistent manner. A standardized method of measuring eight anatomic parameters at the distal radius was developed. By this method, six x-ray films of healed distal radius fractures were subsequently measured by 16 raters. Rater agreement was quantified by using the intraclass correlation coefficient. Tolerance limits were developed in order to estimate the expected margin of error for each parameter. Parameters measured with high rater agreement include ulnar variance, palmar tilt, and radial shift; however, even experienced clinicians did not readily agree on the size of step and gap deformity. Using the method of tolerance limits, one would expect that two randomly chosen clinicians measuring step and gap deformity on a random x-ray film will differ by more than 3 mm at least 10% of the time. Similarly, repeat step or gap measurements by the same observer are expected to differ by more than 2 mm at least 10% of the time. In view of our inability to measure deformity more accurately, the concept of a specific relationship between a given degree of deformity and outcome must be questioned. Prospective research is needed in order to improve our understanding of the precise relationship between malunion and functional outcome.

The appearance of porous bone under fixation plates during fracture healing, attributed to disturbance of blood supply by the plate, has led to new plate designs with reduced plate to bone contact. The fixation stability afforded by these devices, in comparison to implants commonly used for fixation, is not well known. Therefore, the construct stiffnesses of osteotomized synthetic tibiae fixed with dynamic compression plates, external fixators, or two configurations of noncontact plates were compared in axial compression, bending, and torsion with and without cortical contact at the osteotomy site. The results of this study show that (1) the noncontact plated constructs achieve comparable fixation rigidity to constructs using dynamic compression plates or external fixators, if applied at a distance no greater than 5 mm from the surface of the tibia, and (2) the fixation rigidity of the noncontact plate decreases as the distance between plate and bone surface increases.

Carbon fiber rods were developed to provide radiolucent sidebars for external fixation. In the present study, a single-plane, half-pin, double-bar external fixator construct with either stainless-steel tubes or carbon fiber rods was applied on the anteromedial surface of an osteotomized synthetic human tibia and evaluated for fixation rigidity. Testing was performed with the bone fragments in cortical contact and with a 5-mm midshaft gap between the fragments. The sidebars then were loaded to failure in bending. The results of this study show (a) that the carbon fiber rods were 15% stiffer than the stainless-steel tubes (p = 0.009) and (b) that the external fixator with carbon fiber rods achieved approximately 85% of the fixation stiffness of the external fixator with stainless-steel tubes. The loss of stiffness of the external fixator with carbon fiber rods is most likely due to the clamps being less effective in connecting the carbon fiber rods rigidly to the Schanz screws.

The limited contact dynamic compression plate and partial contact plate were designed to decrease contact with cortical bone in an attempt to decrease cortical ischemia, remodeling, and eventual porosis under the plate after use of standard dynamic compression plates. This study quantified cortical bone blood flow beneath the plate with these three different designs in a sheep tibia fracture model. In 18 skeletally immature sheep, the right tibia was fractured and then was internally fixed with an interfragmentary screw and a dynamic compression plate, limited contact dynamic compression plate, or partial contact plate. At 12 weeks, cortical bone perfusion was assessed with laser Doppler flowmetry in nine areas beneath the plate. The baseline (before fracture) cortical bone cell flux averaged 100 +/- 60 mV. After fracture, this decreased to 60 +/- 48 mV (p < 0.0003); immediately after plating, the perfusion averaged 29 +/- 25 mV (p < 0.01). Cortical bone perfusion then increased to 106 +/- 52, 165 +/- 71, and 163 +/- 71 mV at 2, 6, and 12 weeks after fracture (p < 0.001 for all when compared with values after plating). No significant differences in cortical perfusion were seen between the types of plate. Cortical porosity under the plate was assessed with digital density analysis of microradiographs of this region. No significant difference was seen between the types of plate in this analysis or in biomechanical and disulphine blue perfusion analysis. Thus, no significant advantage was seen for the new plate designs used in this model. This lack of advantage may be a result of the immature animals used in the study, the protocol for blood flow measurement, the invasive periosteal stripping employed to create the fracture, or all three. However, as advantages with the new plate designs have been seen in other studies, this area warrants further investigation.

Injury remains the leading public health problem in the United States in terms of cost and years of life lost. It is the number 1 cause of death and disability from birth to 44 years old, which is the most economically productive segment of our population. In the current environment of rapid-pace health care system reform at the state and national levels, trauma care systems have evolved at the forefront; regionalization, continuous quality improvement systems, designation/accreditation systems, registry databases, and cost-effectiveness evaluations are being implemented in many states. In most states, these systems remain immature, but the critical framework is in place. This article attempts to present the current state of cost of injury and effectiveness data, the status of trauma registries, and the evolution of functional outcome research in trauma care.

This study was performed to compare the effects of reamed and unreamed locked intramedullary nailing on blood flow in the callus and early strength of union in a fractured sheep tibia model. After the creation of a standardized short spiral fracture by three-point bending with torsion, each tibia was stabilized by the insertion of a locked intramedullary nail. Ten animals were allocated randomly into two groups: one that had reaming prior to nail insertion and one that did not. Blood flow was measured in real time with use of laser Doppler flowmetry. Endosteal perfusion was determined at the fracture site before and after nail insertion. Perfusion of the callus was measured at three locations (proximal diaphysis, fracture site, and distal diaphysis) and at three time intervals (2, 6, and 12 week follow-up). All animals were killed 12 weeks postoperatively, and the tibiae were tested to failure in four-point bending. Nailing with reaming resulted in a larger decrease in overall endosteal perfusion than nailing without reaming (p < 0.015). The presence or absence of reaming did not affect blood flow within fracture callus. Perfusion of callus was greatest at 6 weeks of follow-up. Bending strength and stiffness were the same in both groups at 12 weeks. The study demonstrated that perfusion of callus and early strength of union are similar following intramedullary nailing with or without reaming.

The orthopaedic surgeon has a multitude of internal fixation devices and techniques available for use in the treatment of subtrochanteric fractures of the proximal femur. The successful use of second-generation locking nails is technically demanding. Close attention to positioning of the patient, reduction of the fracture, placement of the guide-wire, and insertion of the nail and of the proximal and distal locking screws is mandatory. The newer, high-strength hip-screws allow good fixation of a fracture that extends into the piriformis fossa. If medial comminution is present, this technique is best performed in conjunction with indirect reduction and bone-grafting. With proper technique, these devices allow the surgeon to manage predictably a complex subtrochanteric fracture that previously had to be treated with traction or extensive dissection and with (frequently inadequate) internal fixation.

The through-and-through forms of femoral skeletal traction that are often used during intramedullary nailing for femur fractures can present two problems: (a) impingement with the intramedullary nail, requiring repositioning of the traction pin intraoperatively under radiographic control, to a position that may not optimally control the fracture; and (b) the risk of contaminating the intramedullary canal that will soon contain the metallic fixation device, especially when placed in the emergency room or at the bedside. Two new forms of extramedullary skeletal femoral traction are presented. The pullout strength and optimal positioning of these devices on the distal femur were evaluated. The first form of extramedullary traction evaluated was the large AO/ASIF pinless clamp. The second form of extramedullary traction, the extramedullary skeletal clamp, was based on a modification of the Gardner-Wells tong. These two forms of skeletal traction were compared with standard tensioned Kirschner wire (K-wire) through-and-through traction. Six fresh-frozen distal femora from donors (average age 29 years) were used to test the three femoral traction devices. Five of these specimens were skeletally mature. A total of 38 pullout tests were conducted. The pullout strength of the tested devices was in the following descending order: (a) tensioned K-wire; (b) extramedullary skeletal clamp (in the optimal metadiaphyseal position, 77% the strength of the K-wire); and (c) large ASIF pinless clamp (in the optimal metaphyseal position, 46% the strength of the K-wire). The mode of failure for each device was cut out through or from the bone.(ABSTRACT TRUNCATED AT 250 WORDS)

We compared the effects of reamed versus unreamed locked intramedullary nailing on cortical bone blood flow in a fractured sheep tibia model. A standardized spiral fracture was created by three-point bending with torsion, and each tibia was stabilized by insertion of a locked intramedullary nail. Eleven animals were randomized into two groups: one that had reaming before nail insertion and one that did not. Blood flow was measured in real time using laser Doppler flowmetry. Cortical bone perfusion measurements were made at three locations (proximal diaphysis, fracture site, distal diaphysis) and at eight time intervals (prefracture, postfracture, postreaming, postnail insertion, postlocking, and at 2-, 6-, and 12-week follow-up). All animals were killed at 12 weeks postoperatively. After reamed nail insertion, cortical bone perfusion was significantly decreased (p < 0.0009). After unreamed nail insertion, perfusion was decreased less (p < 0.003). Insertion of locking screws did not affect blood flow. Cortical bone perfusion was greater in the unreamed group at completion of the procedure (p < 0.011), at 2-week follow-up (p < 0.006) and at 6-week follow-up (p < 0.027). The findings suggest that cortical revascularization had occurred by 6 weeks in the unreamed group but not until 12 weeks in the reamed group. The study demonstrates that cortical circulation is spared to a greater degree by unreamed nailing. This may be advantageous in severe open tibial fractures where blood supply is already significantly compromised.

Laser Doppler flowmetry (LDF) with the use of a standard metal shafted probe, has been successfully used to study bone blood flow in a wide variety of settings. The use of the standard probe is limited by the requirement that the probe be replaced onto the bone surface or driven into the bone with a trocar. In response to this, a system of implantable, detachable fibers was developed. This system allows repeated measurement over time without repeated surgical manipulation of the area of interest. This study was performed to evaluate the implantable fiber system by determining threshold thickness for flow detection in bone. A flow chamber with perpendicular and end-on flow was designed to collect results under controlled conditions for flow detection. Threshold thickness for bovine cortical and cancellous bone samples was determined after sequentially grinding the specimens and placing them in the flow chamber. A 2% solution of latex circulated in the chamber and each specimen was exposed to both flow directions and both types of probe. The laser Doppler probe was able to detect flow by resting on top of the sample, with the latex on the other side of the sample. The results showed a significantly greater threshold thickness for the standard probes than for the implantable probes, and a significantly greater threshold thickness for trabecular bone than for cortical bone. Despite the reduced threshold thickness with the implantable fiber, this new system was able to consistently detect depth of perfusion of 80-90% of the values for the standard probe.(ABSTRACT TRUNCATED AT 250 WORDS)

We recently treated two patients with engine block-muffler contact burns and greatly underestimated the devastating injuries to bone, deep fascia, and muscle. As a result, each patient required multiple procedures to close their burn wounds. Ten-year data from the University of Washington Burn Unit confirmed our observation that these burns tend to be considerably deeper than suspected. Eighteen patients with contact burns from engine parts were identified from 1980 through 1990. Nine (50%) of these were initially recognized to be fourth-degree and five (28%) were third-degree thermal injuries, showing that these are deep burns. Eight patients required fascial excisions and four required debridement of devascularized bone. The mean burn size was only 6% total body surface area; however, the patients with fourth-degree burns had an average graft take of only 56% and required a mean hospital stay of 44 days. Patients with third-degree burns also had suboptimal graft take and some required prolonged hospitalization. Thirty-six percent of patients required flaps either as the initial procedure or as a second procedure following an autograft. The four patients with partial-thickness burns healed without surgery and their average length of hospital stay was 3 days. Of the entire group, only four healed without surgery and only five healed with a single operation. Our 10-year data indicate that engine block contact burns are usually small, but most are deceptively deep, involving tendon, muscle, or bone. If the burn appears full thickness, suspicion must be very high at the initial surgical procedure that there is deep tissue destruction.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to document functional outcome, we followed fourteen patients who had an injury of the sciatic nerve associated with a displaced acetabular fracture for a mean of twenty-seven months. In three of the patients, the injury was iatrogenic. Electromyography was useful in the localization and determination of the severity of the injury. According to the functional scale that was used, all but one patient had a satisfactory (fair or better) functional outcome, but eleven patients had residual neurological sequelae that ranged from minor paresthesia to footdrop. Seven patients who had an injury of both the tibial and peroneal divisions of the sciatic nerve had complete or nearly complete motor and sensory recovery of the tibial component. The patients who had isolated, mild involvement of the peroneal nerve had a favorable prognosis, but those who had a severe injury of the peroneal component, whether it was isolated or associated with an injury of the tibial component, did not recover good function.

To determine functional outcomes after lower extremity fracture (LEF), a prospective follow-up study of patients admitted to three level I trauma centers for treatment of unilateral LEFs was conducted. In this paper we describe outcomes at 6 months after discharge from the initial hospitalization and examine the relationship between impairment and disability. A total of 444 patients met the entry criteria for the study. Of these 376 (85%) were successfully located and interviewed at 6 months; 302 (68%) returned to the trauma center at 6 months for a clinical assessment by a physical therapist. Study patients were predominantly young (mean age = 32.4), white (72%) men (70%) who were working before the injury (77%). The fractures resulted primarily from motor vehicle crashes (71%); mean hospital LOS was 12 days. Disability was measured using the Sickness Impact Profile (SIP), a well validated patient assessment of health status. The overall SIP score averaged for all patients was 10.2, denoting a moderate level of dysfunction or disability. Analysis of the 12 subscores that constitute the SIP indicate particularly high scores for ambulation (16.7 postdischarge vs. 1.2 preinjury), sleep and rest (14.0 vs. 5.1), emotional behavior (10.5 vs. 2.2), home management (15.1 vs. 2.6), recreation and pastimes (19.0 vs. 4.4), and most notably, work (33.2 vs. 8.3). Further analysis of the subgroup of patients working before the injury shows that 48% had returned to work at 6 months. Correlations between lower extremity impairment (range of motion, muscle strength, and pain) and the ambulation subscore of the SIP were high. However, correlations between impairment and more global areas of activity such as home management, work, and recreation were considerably lower. These results suggest that other factors, over and above the extent of physical impairment, significantly influence broader disability outcomes such as return to work. Further research is needed to define these factors so that effective interventions after acute care can be identified and appropriately targeted.

Miniature swine were used to study the effect of cervical fracture on femoral head blood flow. Laser Doppler flowmetry was used to evaluate femoral head blood flow before and after the fracture, after internal fixation with or without compression, and 8 weeks post-fracture. Fluorescent bone-labeling was performed at 2, 4 and 6 weeks post-fracture. Femoral head blood flow decreased to 40 percent of baseline following fracture, partly from the disruption of venous drainage. Histologically, all femoral heads showed some degree of trabecular thinning, microfracture, and neovascularization when compared with controls. Analyses of the laser Doppler flowmetry data, fluorescent label histology, microradiography and bone densitometry indicated that late (4-6 weeks) revascularization produces severe trabecular mechanical weakening and resultant femoral head collapse. Femoral head ischemia following fracture probably falls along a continuum, with only the more severe cases proceeding to mechanical collapse. Femoral neck fractures in the minipig produce femoral head necrosis of a severity and incidence which closely parallels that of the human population; thus, the minipig is a useful model for further study of complications following femoral neck fracture in humans.

Although radial nerve palsy associated with a closed humeral shaft fracture may be managed by observation, it is our experience that an open humeral shaft fracture with radial nerve palsy requires exploration of the nerve. In a series of 14 patients with radial nerve palsy caused by an open humeral shaft fracture, 9 (64%) of the 14 patients had a radial nerve that was either lacerated or interposed between the fracture fragments. There was an equal incidence of radial nerve lacerations or entrapments in types I, II, and III open humeral shaft fractures. Epineural radial nerve repair, done primarily or secondarily, provided a satisfactory return of radial nerve function. Rigid fixation of the associated fracture is the recommended treatment.

To determine patient-perceived functional outcome after lower extremity fracture (LEF), a prospective, follow-up study of patients managed at three level I trauma centers was conducted. Patients with unilateral LEF involving the acetabulum and distally were eligible for the study. A total of 444 patients were enrolled. Of these, 363 (82%) were interviewed at 6 months postdischarge. Study patients were predominantly young (mean age 34 years), white (72%) men (71%) who had been working preinjury (78%). Their injuries resulted primarily from motor vehicle crashes (73%); 30% had more than one fracture to the same extremity. Functional status was measured using the Sickness Impact Profile (SIP), a well-validated, general health status instrument. Mean 6-month SIP scores were significantly worse (higher) than those based on preinjury activities (9.8 vs. 2.5) (p < 0.01). Overall disability levels were moderate compared with other health conditions. Analysis of the 12 subscores comprising the SIP indicated particularly high scores in ambulation (16.2 postdischarge vs. 1.1 preinjury), sleep/rest (13.1 vs. 5.1), household management (14.5 vs. 2.6), recreation (17.6 vs. 4.2), emotional well-being (9.9 vs. 2.1), and most significantly work (33.2 vs. 8.8). Of those working preinjury, only 49% had returned by 6 months. SIP scores were highest for persons with three or more fractures to the same extremity and for fracture patterns typical of high-energy forces.

Although closed interlocking femoral nailing is generally considered to be a difficult but effective procedure, the true incidence of technical complications has not been well documented. Similarly, long-term and functional patient-oriented data are limited. We reviewed our experience with an interlocking nail system that was introduced in our institution in October 1987. One hundred and twenty-three patients were retrospectively reviewed with particular attention to technical complications (Group I). A second group of 144 patients with femoral shaft fractures were reviewed prospectively as a part of our Orthopaedic Trauma Outcome Database (Group IIA). In the earlier retrospective group, the technical complications in 123 cases included one distal screw fracture, one broken drill bit left (in situ), one "missed" locking distal screw, and three cases where comminution at the fracture site was increased. In the prospective group of 144 fractures, the technical complications included two "missed" distal locking screws, two broken screws, and one bent nail due to additional secondary trauma. In a third group of 56 patients (Group IIB) selected from Group IIA, an abbreviated functional assessment was performed at a minimum of 12 months postinjury. Of this group, 37% of the patients had pain that was described as related to barometric changes and was either constant or activity related; 39% had some limitation in ability to ambulate or stand. Nine percent had to obtain new employment or seek job modifications. Based on our data we conclude that closed intramedullary nailing can be done at a Level I Trauma Center with relatively few technical complications, but the functional outcomes are not as good as had been previously believed.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo studies of rat sciatic nerves in models of immediate and delayed repairs demonstrated the viscoelastic properties of the nerve and the inverse correlation between nerve blood flow and tension. In both the proximal and distal segments of the divided nerve in models of immediate and delayed repairs, the nerve blood flow decreased approximately 50% with substantial recovery in 30 minutes after 8% elongation, whereas 15% elongation produced approximately an 80% reduction in blood flow with minimal recovery. However, the baseline blood flow of the nerves in the delayed-repair model was nearly two times higher than that of the acutely injured nerves. Maximal decrease in nerve tension and corresponding increase in blood flow occurred within the first 20 minutes after elongation. The suture pull-out with failure of the repairs occurred at more than 15% elongation for all nerves. The previously divided nerves had a sixfold greater decrease in length than the acutely divided nerves (p less than 0.02). For repairs of large nerves where vascular ingrowth is likely to be incomplete, elongation of more than 8% may cause ischemia that is detrimental to nerve regeneration. Mechanical failure of the repairs occurs after elongation of 16% to 17%. The combination of nerve ischemia and mechanical failure of suture repairs suggests that surgeons should be careful to limit the use of elongation in acute and delayed repairs.

In order to investigate the effects of short-term ischemia on cortical bone microperfusion, an isolated porcine tibia diaphyseal preparation based on intact nutrient vessels was developed. Laser Doppler flowmetry (LDF) was utilized to assess continuously the cortical microcirculation and the response to short-term ischemia. The femoral artery was isolated and clamped to develop the condition of bone ischemia. On release of the clamp, reactive hyperemia was documented in all animals. Using a roller pump connected to a segment of femoral artery, the same preparation was utilized to investigate the effect of a changing femoral artery flow on the cortical microcirculation. A positive correlation between LDF output and change in arterial inflow (r = 0.64) was defined. This model has the potential for studying the effect of ischemia on bone cell viability.

Because of the controversy surrounding the selection of the surgical approach for the operative management of femoral head fractures, we retrospectively reviewed the combined experience with femoral head fractures at two major trauma centers. Forty-three femoral head fractures in 41 patients were identified. Twenty-six of the 43 fractures were Pipkin types I and II, and were managed operatively. Of the 26 patients, 12 with > 2 years of follow-up were managed with posterior surgical approaches and 12 with anterior surgical approaches. These patients were assessed with respect to operative time, estimated blood loss and function, and the radiographs for reduction, avascular necrosis, and heterotopic ossification. There was a significant decrease in operative time, estimated blood loss, and improved visualization and fixation with the anterior approach; however, there was a significant increase in functionally significant heterotopic ossification. The functional results in the two groups were identical; 67% good and excellent in each. There were no cases of avascular necrosis of the femoral head associated with an anterior approach. Because of the greater ease of access to the fracture, the anterior approach is recommended when operative reduction of a displaced Pipkin type I or II is indicated, but newer methods of minimizing heterotopic ossification must be developed.

Laser Doppler Flowmetry (LDF) has been shown to be a useful tool in the experimental and clinical measurement of bone blood flow. Two LDF receiving fiber channel systems, one with a 2mW He-Ne tube laser source and the other with an infrared diode laser source, were compared with specific reference to their light attenuation through three types of bone as well as their threshold thickness for the same specimens. The threshold thickness was higher for the infrared diode system for all three bone types whereas the attenuation was identical. The demonstrated differences were most likely due to the criteria established for flow detection; the infrared diode system has a greater degree of amplification of the output signal, yielding a higher value at each thickness of bone. The two systems will produce similar output data when used for experimental analysis of bone blood flow.

Beginning in October 1986, we prospectively evaluated the AO/ASIF Universal Femoral Nail in the treatment of traumatic (89 nails) and reconstructive (11 nails) problems of the femur. For treatment of isolated femoral fractures, the mean time of patient positioning and nail insertion was 2.4 hours with a mean blood loss of 389 ml. Seventy-eight per cent of the patients were followed for a minimum of 12 months. There were no infections, one case of nail failure, two cases of screw fracture, and three nonunions. Sixteen nails have been uneventfully removed. The AO/ASIF femoral nail provides results comparable to other intramedullary interlocking devices.

The surgical management of osteomyelitis includes radical debridement on nonviable bone. Laser Doppler flowmetry is a method for directly assessing the functional microcirculation in bone. The early results of the use of this technique as a surgical adjunct in the management of osteomyelitis are promising.

Over a four-year period, twenty-four patients who had a complex fracture of the acetabulum were treated by the same surgeon. The operation consisted of open reduction and internal fixation with combined anterior and posterior exposures during the same period of anesthesia. The cases of these patients were reviewed to ascertain whether access to both acetabular columns during the same procedure facilitates open reduction and internal fixation and to determine the indications for this combined procedure. As determined by intraoperative assessment and at follow-up examination four to thirty-two months postoperatively, anatomical reduction and rigid fixation were achieved in 88 per cent of the patients. No patient had an infection of the wound. All twenty-four patients had some degree of heterotopic ossification; as defined by Brooker et al., it was Class I in seven, Class II in thirteen, Class III in three, and Class IV in one. However, the heterotopic ossification limited motion of the hip enough to impair function in only two patients. We concluded that combined anterior and posterior exposures facilitate reduction and fixation and that these approaches should be used during the same period of anesthesia whenever anatomical reduction and rigid internal fixation cannot be achieved through a single exposure. Heterotopic ossification should be expected postoperatively, but it is rarely clinically important, at least in the short term.