Saam Morshed

Variability in the Assessment of Fracture-Healing in Orthopaedic Trauma Studies

BACKGROUND There is a lack of consensus among orthopaedic surgeons in the assessment of fracture-healing. We conducted a systematic review of recent clinical studies of long-bone fracture care that were published in three major orthopaedic journals to identify current definitions of fracture-healing. METHODS MEDLINE and the computerized databases for The Journal of Bone and Joint Surgery (American Volume), The Journal of Bone and Joint Surgery (British Volume), and the Journal of Orthopaedic Trauma were searched from January 1996 through December 2006 with use of title, abstract, keyword, and medical subject headings. Therapeutic clinical studies of long-bone fractures of the appendicular skeleton in adults in which fracture-healing was assessed were selected. Two reviewers independently identified articles and extracted data. Any disagreement was resolved by consensus. We qualitatively and quantitatively summarized the definition of fracture union and the reliability of the assessment of radiographic fracture-healing. RESULTS One hundred and twenty-three studies proved to be eligible. Union was defined on the basis of a combination of clinical and radiographic criteria in 62% of the studies, on the basis of radiographic criteria only in 37%, and on the basis of clinical criteria only in 1%. Twelve different criteria were used to define fracture union clinically, and the most common criterion was the absence of pain or tenderness at the fracture site during weight-bearing. In studies involving the use of plain radiographs, eleven different criteria were used to define fracture union, and the most common criterion was bridging of the fracture site. A quantitative measure of the reliability of the radiographic assessment of fracture union was reported in two studies. CONCLUSIONS We found a lack of consensus with regard to the definition of fracture-healing in the current orthopaedic literature. Without valid and reliable clinical or radiographic measures of union, the interpretation of fracture care studies remains difficult.

Comparison of cemented and uncemented fixation in total hip replacement: a meta-analysis

Background The choice of optimal implant fixation in total hip replacement (THR)—fixation with or without cement—has been the subject of much debate. Methods We performed a systematic review and meta-analysis of the published literature comparing cemented and uncemented fixation in THR. Results No advantage was found for either procedure when failure was defined as either: (A) revision of either or both components, or (B) revision of a specific component. No difference was seen between estimates from registry and single-center studies, or between randomized and non-randomized studies. Subgroup analysis of type A studies showed superior survival with cemented fixation in studies including patients of all ages as compared to those that only studied patients 55 years of age or younger. Among type B studies, cemented titanium stems and threaded cups were associated with poor survival. An association was found between difference in survival and year of publication, with uncemented fixation showing relative superiority over time. Interpretation While the recent literature suggests that the performance of uncemented implants is improving, cemented fixation continues to outperform uncemented fixation in large subsets of study populations. Our findings summarize the best available evidence qualitatively and quantitatively and provide important information for future research.

Delayed Internal Fixation of Femoral Shaft Fracture Reduces Mortality Among Patients with Multisystem Trauma

BACKGROUND Fractures of the femoral shaft are common and have potentially serious consequences in patients with multiple injuries. The appropriate timing of fracture repair is controversial. The purpose of the present study was to assess the effect of timing of internal fixation on mortality in patients with multisystem trauma. METHODS We performed a retrospective cohort study with use of data from public and private trauma centers throughout the United States that were reported to the National Trauma Data Bank (version 5.0 for 2000 through 2004). The study included 3069 patients with multisystem trauma (Injury Severity Score, > or =15) who underwent internal fixation of a femoral shaft fracture. The time to treatment was defined in categories as the time from admission to internal fixation: t(0) (twelve hours or less), t(1) (more than twelve hours to twenty-four hours), t(2) (more than twenty-four hours to forty-eight hours), t(3) (more than forty-eight hours to 120 hours), and t(4) (more than 120 hours). The relative risk of in-hospital mortality when the four later periods were compared with the earliest one was estimated with inverse probability of treatment-weighted analysis. Subgroups with serious head or neck, chest, abdominal, and additional extremity injury were investigated. RESULTS When compared with that during the first twelve hours after admission, the estimated mortality risk was significantly lower in three time categories: t(1) (relative risk, 0.45; 95% confidence interval, 0.15 to 0.98; p = 0.03), t(3) (relative risk, 0.58; 95% confidence interval, 0.28 to 0.93; p = 0.03), and t(4) (relative risk, 0.43; 95% confidence interval, 0.10 to 0.94; p = 0.03). Patients with serious abdominal trauma (Abbreviated Injury Score, > or =3) experienced the greatest benefit from a delay of internal fixation beyond twelve hours (relative risk, 0.82 [95% confidence interval, 0.54 to 1.35] for patients with an Abbreviated Injury Score of <3, compared with 0.36 [95% confidence interval, 0.13 to 0.87] for those with an Abbreviated Injury Score of > or =3) (p value for effect modification, 0.09). CONCLUSIONS Delayed repair of femoral shaft fracture beyond twelve hours in patients with multisystem trauma, which may allow time for appropriate resuscitation, reduces mortality by approximately 50%. Patients with serious abdominal injury benefit most from delayed treatment. These results support delaying definitive treatment of long-bone injuries in patients with multisystem trauma as a means of so-called damage-control in order to reduce adverse outcomes.

Hierarchy of Evidence: Where Observational Studies Fit in and Why We Need Them

Although randomized controlled designs are considered the so-called gold standard in medical trials and sit atop the hierarchy of evidence in evidence-based medicine, there are situations in which they are impractical or unethical to undertake, especially in surgical trials. Then, observational studies often provide the best source of information. In this paper, we use examples from the literature to explain the importance of observational studies in furthering the boundaries of orthopaedic surgery and knowledge of musculoskeletal disorders.

Outcome Assessment in Clinical Trials of Fracture-Healing

Although there are numerous methods for defining fracture-healing in clinical studies, no consensus exists regarding the most valid and reliable manner for assessing union or for determining which outcomes are most important. This article summarizes and describes methods for the clinical assessment of fracture-healing and reports results from a systematic review of prevalent definitions currently used in published clinical studies. Conventional radiography and ad hoc clinical definitions continue to be the most commonly used means of assessing fracture-healing in clinical studies. Investigators must improve upon and apply more rigorous outcome assessment in clinical trials, emphasize patient-important outcomes, and report factors that may bias estimated effects.

Use of cost-effectiveness analysis to evaluate new technologies in orthopaedics: The case of alternative bearing surfaces in total hip arthroplasty

BACKGROUND Alternative bearing surfaces offer the potential to reduce wear and improve implant longevity following total hip arthroplasty. However, these technologies are associated with higher costs, the potential for unintended consequences, and uncertain benefits in terms of long-term survival of the implants. The purpose of this study was to evaluate the cost-effectiveness of the use of alternative bearings in total hip arthroplasty. METHODS A decision-analysis model was constructed to estimate the cost-effectiveness of the use of alternative bearings for patients undergoing total hip arthroplasty. Model inputs, including costs, clinical outcome probabilities, and health utility values, were derived from a review of the literature. Sensitivity analyses were performed to evaluate the impact of patient age at the time of surgery, implant costs, and reductions in revision rates on the cost-effectiveness of alternate bearing surfaces. RESULTS In a population of fifty-year-old patients, use of an alternative bearing with an incremental cost of 2000 dollars would be cost-saving over the individuals lifetime if it were associated with at least a 19% reduction in the twenty-year implant failure rate when compared with the failure rate for a conventional bearing. In a population of patients over the age of sixty-three years, the same implant would be associated with higher lifetime costs than would a conventional bearing, regardless of the presumed reduction in the revision rate. Conversely, an alternative bearing that adds only 500 dollars to the cost of a conventional total hip arthroplasty could be cost-saving in a population of patients over the age of sixty-five years, even if it were associated with only a modest reduction in the revision rate. In a population of patients over the age of seventy-five years, no alternative bearing would be associated with lifetime cost-savings, regardless of the cost or the presumed reduction in the revision rate. CONCLUSIONS The cost-effectiveness of alternative bearings is highly dependent on the age of the patient at the time of surgery, the cost of the implant, and the associated reduction in the probability of revision relative to that associated with conventional bearings. Our findings provide a quantitative rationale for requiring greater evidence of effectiveness in reducing the probability of implant failure when more costly alternative bearings are being considered, particularly for older patients.

Risk factors for failure of locked plate fixation of distal femur fractures: an analysis of 335 cases.

Objectives: Locked plating has become a standard method to treat supracondylar femur fractures. Emerging evidence indicates that this method of treatment is associated with modest failure rates. The goals of this study were to determine risk factors for complications and to provide technical recommendations for locked plating of supracondylar femur fractures. Design: Retrospective review. Setting: Three level I or II trauma centers. Patients/participants: Three hundred twenty-six patients with 335 distal femur fractures (OTA 33A or C, 33% open) treated with lateral locked plates were studied. The average patient age was 57 years (range 17–97 years), 55% were women, 34% were obese, 19% were diabetic, and 24% were smokers. Intervention: All patients were managed with open reduction internal fixation using a lateral distal femoral locked plate construct that included locked screws in the distal fragment and nonlocked, locked, or a combination of locked and nonlocked screws in the proximal fragment. Main Outcome Measurements: Risk factors for reoperation to promote union, deep infection, and implant failure. Results: After the index procedure, 64 fractures (19%) required reoperation to promote union, including 30 that had a planned staged bone grafting because of the metaphyseal defect after debridement of an open fracture. Independent risk factors for reoperation to promote union and deep infection included diabetes and open fracture. Risk factors for proximal implant failure included open fracture, smoking, increased body mass index, and shorter plate length. Conclusions: The identified risk factors for reoperation to promote union and complications included open fracture, diabetes, smoking, increased body mass index, and shorter plate length. Most factors are out of surgeon control but are useful when considering prognosis. Use of relatively long plates is a technical factor that can reduce risk for fixation failure. Level of Evidence: Prognostic level II. See instructions for authors for a complete description of levels of evidence.

Clinical impact of obesity on stability following revision total hip arthroplasty.

Similar outcomes have been reported for obese and nonobese patients after primary total hip arthroplasty (THA), indicating obesity is not a contraindication to total hip arthroplasty. However, obese patients may develop implant failure and require revision THA. We compared the outcomes of revision THA in a matched cohort of obese and nonobese patients. Patients were stratified into two groups according to BMI (body mass index, kg/m2): Group 1 included 31 obese patients (BMI > 35), and Group 2 included 62 nonobese patients (BMI < 30) matched on age, gender, and type of revision procedure. Obese patients had increased total operating room time, a higher rate of discharge to a skilled nursing facility, and a higher dislocation rate (p < 0.05). Seven patients in the obese group underwent revision surgery, six of whom underwent additional reoperations to treat recurrent postoperative dislocation. Obese patients should be counseled about the increased risk of dislocation that can occur after revision THA.Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Quantification of the Upper and Second Sacral Segment Safe Zones in Normal and Dysmorphic Sacra

Objectives: To quantify the obliquity and dimensions of the upper and second sacral segment iliosacral screw safe zones and to determine the differences between normal and dysmorphic sacral morphology. Design: Retrospective cohort. Setting: University Level I trauma center. Patients/Participants: Fifty patients with pelvic computed tomography scans. Intervention: All sacra were characterized as normal or dysmorphic based on plain pelvic radiographs and previously described criteria. Multiple computed tomography scan reconstructions were viewed and manipulated simultaneously with 6 degrees of freedom to allow for custom visualization in any plane. Main Outcome Measurements: In each patient, a unique reconstruction plane was created perpendicular to the safe zone axis. The narrowest safe zone cross-sectional area was measured. Next, on simulated pelvic outlet and inlet views, safe zone obliquity and width were measured. Finally, the space available for a transverse screw was assessed. Measurements were performed for both upper and second sacral segment. Values for normal and dysmorphic safe zones were compared. Results: Sacral dysmorphism was identified in 22 patients. In these sacra, the upper sacral segment safe zone cross-section was 36% smaller than in normal sacra (P < 0.001). No transverse screws could be placed, but accommodating for the caudal to cranial obliquity (30° versus 21° in normals, P < 0.001) and posterior to anterior obliquity (15% versus 4% in normals, P < 0.001) of the safe zone, an iliosacral screw at least 75 mm in length could be placed safely in 91% of patients. A transverse screw could be placed in 75% of normal sacra. In the second segment safe zone, the cross-sectional area was more than twice as large in dysmorphic sacra compared to normals (220 mm2 versus 109 mm2, P < 0.001). The obliquity was not different on either the inlet or outlet views between groups. A transverse screw could be placed at this level in 95% of those with dysmorphic sacra and in only 50% of normal sacra. Conclusions: Sacral dysmorphism occurred in 44% of patients in this consecutive series. Many anatomic differences were consistently found between the two morphologies with clinical relevance to iliosacral screw placement. Specifically, the dysmorphic upper sacral segment safe zone is significantly smaller and more obliquely oriented but is still large enough to accommodate an iliosacral screw in nearly all patients. The second sacral segment safe zone is approximately transversely oriented in both sacral types but is more than twice as large in dysmorphic sacra. This segment may be a primary fixation opportunity in patients with sacral dysmorphism.

Design, conduct, and interpretation of nonrandomized orthopaedic studies: a practical approach. (All) evidence matters.

The most sophisticated practice of evidence-based orthopaedics requires a clear delineation of relevant clinical questions, a thorough search of the literature relating to the questions, a critical appraisal of available evidence and its applicability to the clinical situation, and a balanced application of the conclusions to the clinical problem. The balanced application of the evidence (i.e., clinical decision-making) is the central point of practicing evidence-based medicine and involves an integration of our clinical expertise and judgment with …