Current concepts review. Methods for locating missing patients for the purpose of long-term clinical studies.
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Follow-Up Studies↗
Biomedical subjects
M F Swiontkowski
Publications and source records attributed to M F Swiontkowski.
Angulated screw placement in the lateral condylar buttress plate for supracondylar femoral 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.
Aged↗
Treatment of type II, IIIA, and IIIB open fractures of the tibial shaft: a prospective comparison of unreamed interlocking intramedullary nails and half-pin external fixators.
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.
Adolescent↗
Quantitative assessment of bone injury and repair after reamed and unreamed locked intramedullary nailing.
BACKGROUND: Cortical reaming and intramedullary nail insertion injure the medullary vascular system. Little attention has been directed toward quantitative assessment of bone injury and repair after locked intramedullary nailing of long-bone fractures with and without reaming. The effects of reamed versus unreamed locked intramedullary nailing on cortical porosity and new bone formation were compared in a sheep fractured tibia model. METHODS: After creation of a standardized spiral fracture by three-point bending with torsion, each tibia was stabilized by insertion of a locked intramedullary nail. Ten sheep were randomized into two groups, one that had reaming before nail insertion and one that did not. Fluorochromes were given 2 weeks (xylenol orange), 6 weeks (calcein green), and 12 weeks (tetracycline) postoperatively. All animals were killed at 12 weeks postoperatively. Cortical porosity and new bone formation were determined for the proximal diaphysis, fracture site, and distal diaphysis. RESULTS: Overall cortical porosity was greater with reamed nails than with unreamed nails (p = 0.02). Porosity in the inner cortex (18.3% (reamed) vs. 14.3% (unreamed); p = 0.09) and outer cortex (16.8% (reamed) vs. 12.2% (unreamed); p = 0.04) was greater in the reamed group. With reamed nails only, there was less new bone formation at 2 (p = 0.04) and 12 (p = 0.05) weeks in the inner cortex compared with the central cortex and outer cortex. Overall, there was no difference between reamed and unreamed nails in the amount of new bone formation at 2, 6, or 12 weeks. CONCLUSIONS: This study demonstrates that greater injury or overall cortical porosity is associated with reamed nail insertion. There is no difference, however, between the amount of new bone formation after reamed and unreamed nail insertion. Nail insertion without reaming may be initially advantageous when tibial cortical vascularity is compromised, by limiting further injury to cortical bone. This may be important with open tibial fractures in which there is a significant risk of infection after injury. Between 2 and 12 weeks after injury, neither reamed nor unreamed nail insertion seems to have a significant advantage with respect to the amount of new bone formation that occurs.
Animals↗
Return to work following injury: the role of economic, social, and job-related factors.
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.
Absenteeism↗
Closed fractures of the tibial shaft. A meta-analysis of three methods of treatment.
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.
Casts, Surgical↗
Correlation between the measures of impairment, according to the modified system of the American Medical Association, and function.
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.
Activities of Daily Living↗
Clinical and functional outcomes of internal fixation of displaced pilon fractures.
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.
Adolescent↗
Norian SRS cement augmentation in hip fracture treatment. Laboratory and initial clinical results.
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.
Aged↗
Stabilization of pelvic ring disruptions.
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.
Child↗
Interobserver variation in the AO/OTA fracture classification system for pilon fractures: is there a problem?
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.
Ankle Injuries↗
Relationship between the volume of total hip replacements performed by providers and the rates of postoperative complications in the state of Washington.
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.
Aged↗
Comparison of the Musculoskeletal Function Assessment questionnaire with the Short Form-36, the Western Ontario and McMaster Universities Osteoarthritis Index, and the Sickness Impact Profile health-status measures.
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.
Activities of Daily Living↗
Development of a musculoskeletal extremity health status instrument: the Musculoskeletal Function Assessment instrument.
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.
Adolescent↗
Musculoskeletal Function Assessment instrument: criterion and construct validity.
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).
Adolescent↗
Augmentation of femoral neck fracture fixation with an injectable calcium-phosphate bone mineral cement.
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.
Adult↗
Effect of periosteal stripping on cortical bone perfusion: a laser doppler study in sheep.
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.
Animals↗