Focussed classification of scapula fractures: failure of the lateral scapula suspension system.

INTRODUCTION: Following an increase in the incidence of scapular fractures and interest in the outcome of their treatment, a basic classification system was developed for ease of use in the emergency setting. It has been expanded to a comprehensive system to allow for more in-depth classification of scapular fractures for clinical research and surgical decision making. It focusses on three specific regions of the scapula: the scapular body, the glenoid fossa and the lateral scapular suspension system (LSSS). This article presents a classification of the LSSS involvement to better characterise the injuries of this region and to emphasise its relevance to evaluation of the position of the scapula, hence the glenoid fossa, and so the centre of rotation of the shoulder joint. METHODS: An iterative consensus and evaluation process comprising an international group of seven experienced shoulder specialist and orthopaedic trauma surgeons was used to specify and evaluate the failure of the LSSS associated with scapula fractures. This was supported by a series of agreement studies. The system considered lack of involvement (S0), incomplete (S1) and complete (S2) failure of the LSSS. The last evaluation was conducted on a consecutive collection of 120 scapula fractures documented by three-dimensional computed tomography (3D CT) reconstruction videos. RESULTS: Surgeons agreed on the involvement/failure of the LSSS in 47% of the 120 cases with an overall Kappa of 0.54. The sample most likely included 70 S0, 29 S1 and 21 S2 cases, where surgeons showed median classification accuracies of 93%, 71% and 80% for these categories, respectively. While two surgeons showed some uncertainty about their classification, the remaining surgeons only failed to identify LSSS failure in <20% of the cases. Kappa coefficients of reliability for classification of incomplete and complete LSSS involvement according to subcategories were 0.85 and 0.82, respectively. CONCLUSION: While LSSS involvement can be reliably identified, its characterisation regarding complexity is problematic even with 3D CT images. The proposed LSSS system is considered clinically relevant and sufficient to further assess its role in treatment-decision processes and outcome prognosis.

Outcome after fixation of ankle fractures with an injury to the syndesmosis: the effect of the syndesmosis screw.

The purpose of this study was to compare the clinical and radiological outcome of patients with intact, broken and removed syndesmosis screws after Weber B or C ankle fracture with an associated injury to the syndesmosis. We hypothesised that there would be no difference. Of a possible 142 patients who fulfilled our inclusion criteria, 52 returned for clinical and radiological assessment at least one year after surgery. Of these, 27 had intact syndesmosis screws, ten had broken screws, and 15 had undergone elective removal of the screw. The mean American Orthopaedic Foot and Ankle Society ankle/hindfoot score was 83.07 (sd 13.59) in the intact screw group, 92.40 (sd 12.69) in the broken screw group, and 85.80 (sd 11.33) in the removed screw group (p = 0.0466). There was no difference in clinical outcome of patients with intact or removed syndesmotic screws. Paradoxically, patients with a broken syndesmosis screw had the best clinical outcome. Our data do not support the removal of intact or broken syndesmosis screws, and we caution against attributing post-operative ankle pain to breakage of the syndesmosis screw.

Indometacin as prophylaxis for heterotopic ossification after the operative treatment of fractures of the acetabulum.

Our study was designed to compare the effect of indometacin with that of a placebo in reducing the incidence of heterotopic ossification in a prospective, randomised trial. A total of 121 patients with displaced fractures of the acetabulum treated by operation through a Kocher-Langenbeck approach was randomised to receive either indometacin (75 mg) sustained release, or a placebo once daily for six weeks. The extent of heterotopic ossification was evaluated on plain radiographs three months after operation. Significant ossification of Brooker grade III to IV occurred in nine of 59 patients (15.2%) in the indometacin group and 12 of 62 (19.4%) receiving the placebo. We were unable to demonstrate a statistically significant reduction in the incidence of severe heterotopic ossification with the use of indometacin when compared with a placebo (p = 0.722). Based on these results we cannot recommend the routine use of indometacin for prophylaxis against heterotopic ossification after isolated fractures of the acetabulum.

Attitudes of orthopaedic trauma surgeons regarding current controversies in the management of pelvic and acetabular fractures.

A closed-ended questionnaire was mailed to all 363 active members of the Orthopaedic Trauma Association. It directed, toward practicing pelvic and acetabular surgeons, questions pertaining to practice demographics and preferred methods for detection and prevention of deep venous thrombosis (DVT), nerve injury, and heterotopic ossification (HO). Questionnaires were received from 226 surgeons (62 percent). Of the surgeons who responded, 181 (80 percent) perform pelvic-fracture and acetabular-fracture surgery; only questionnaires from this group were analyzed. Standard statistical methods were used to perform both univariate and multivariate analyses. Preoperative DVT screening was performed by 48 percent of the surgeons; ultrasound was the most commonly used modality (82 percent). Preoperative DVT prophylaxis was administered by 88 percent of those surveyed; the majority (78 percent) used sequential compression devices. Postoperative prophylaxis was used by 99 percent; the most commonly used modality was sequential compression devices. Analysis suggests that fellowship-trained surgeons and surgeons in practice for fewer than twenty years are more likely to use preoperative DVT prophylaxis. HO prophylaxis was administered by 88 percent; the most commonly used modality was indomethacin. Intraoperative nerve monitoring was performed by only 15 percent of the respondents. Most surgeons employed prophylactic measures to prevent DVT and HO. The wide variation in type of prophylaxis and reasons for use suggests that controversy will continue, and a standard of care for these conditions has yet to be defined. Very few surgeons use intraoperative nerve monitoring routinely.

The floating shoulder: clinical and functional results.

BACKGROUND: Displaced ipsilateral fractures of the clavicle and the glenoid neck are a complex injury pattern that is usually the result of high-energy trauma. The treatment of these injuries is controversial, as good results have been reported with both operative and nonoperative treatment. METHODS: Nineteen patients who had sustained a displaced fracture of the glenoid neck with an ipsilateral clavicular fracture or acromioclavicular separation (floating shoulder) were retrospectively evaluated. The treatment was nonoperative in twelve patients and operative in seven. At the time of final follow-up, standard radiographs were made and all patients were examined by a physical therapist and either a fellowship-trained shoulder surgeon or an orthopaedic traumatologist. In addition, each patient responded to three different validated objective functional outcome measures: the Short Form-36, the American Shoulder and Elbow Surgeons Shoulder Scale, and the Disabilities of the Arm, Shoulder and Hand Questionnaire. Isokinetic strength-testing was performed, and strength in internal and external rotation was compared with that of the uninvolved shoulder. The main outcome measures included fracture-healing, functional outcome, patient satisfaction, and muscular strength. RESULTS: With regard to range of motion, only the amount of forward flexion was found to be significantly greater in the operatively treated group (p = 0.03). The operatively treated shoulders were found to be weaker in external rotation at 300 degrees /sec and weaker in internal rotation at 180 degrees /sec. When normalized to hand dominance, however, the numbers were too small to identify any significant difference. There was no significant difference between groups with regard to the three functional outcome measures. CONCLUSIONS: Good results may be seen both with and without operative treatment. Therefore, we cannot universally recommend operative treatment for a double disruption of the superior suspensory shoulder complex. Treatment must be individualized for each patient.

A prospective evaluation of the clinical utility of the lower-extremity injury-severity scores.

BACKGROUND: High-energy trauma to the lower extremity presents challenges with regard to reconstruction and rehabilitation. Failed efforts at limb salvage are associated with increased patient mortality and high hospital costs. Lower-extremity injury-severity scoring systems were developed to assist the surgical team with the initial decision to amputate or salvage a limb. The purpose of the present study was to prospectively evaluate the clinical utility of five lower-extremity injury-severity scoring systems. METHODS: Five hundred and fifty-six high-energy lower-extremity injuries were prospectively evaluated with use of five injury-severity scoring systems for lower-extremity trauma designed to assist in the decision-making process for the care of patients with such injuries. Four hundred and seven limbs remained in the salvage pathway six months after the injury. The sensitivity, specificity, and area under the receiver operating characteristic curve were calculated for the Mangled Extremity Severity Score (MESS); the Limb Salvage Index (LSI); the Predictive Salvage Index (PSI); the Nerve Injury, Ischemia, Soft-Tissue Injury, Skeletal Injury, Shock, and Age of Patient Score (NISSSA); and the Hannover Fracture Scale-97 (HFS-97) for ischemic and nonischemic limbs. The scores were analyzed in two ways: including and excluding limbs that required immediate amputation. RESULTS: The analysis did not validate the clinical utility of any of the lower-extremity injury-severity scores. The high specificity of the scores in all of the patient subgroups did confirm that low scores could be used to predict limb-salvage potential. The converse, however, was not true. The low sensitivity of the indices failed to support the validity of the scores as predictors of amputation. CONCLUSIONS: Lower-extremity injury-severity scores at or above the amputation threshold should be cautiously used by a surgeon who must decide the fate of a lower extremity with a high-energy injury.

Characterization of patients with high-energy lower extremity trauma.

PURPOSE: (a) to report the demographic, socioeconomic, behavioral, social, and vocational characteristics of patients enrolled in a study to examine outcomes after high-energy lower extremity trauma (HELET) and to compare them with the general population; (b) to determine whether characteristics of patients undergoing limb salvage versus amputation after HELET are significantly different from each other. DESIGN AND STUDY POPULATION: A prospective study of 601 patients admitted with high-energy lower extremity trauma to eight Level I trauma centers. PROCEDURES: Patients were evaluated during the initial hospitalization. They are being followed up for 24 months postinjury. Study patients are compared with the general population by using census information, population survey data, and published norms. Characteristics of patients undergoing limb salvage versus amputation are also compared. RESULTS: Most patients were male (77 percent), white (72 percent), and between the ages of twenty and forty-five years (71 percent). Seventy percent graduated from high school (compared with 86 percent nationally) (p < 0.05). One fourth lived in households with incomes below the federal poverty line, compared with 16 percent nationally (p < 0.05). The percentage with no health insurance (38 percent) was also higher than in the general population (20 percent) (p < .05). The percentage of heavy drinkers was over two times higher than reported nationally (p < 0.01). Study patients were slightly more neurotic and extroverted and less open to new experiences. When patient characteristics were compared for those undergoing amputation versus limb salvage, no significant differences were found among any of the variables (p > 0.05). CONCLUSION: In conclusion, LEAP patients differ in important ways from the general population. However, the decision to amputate verus reconstruct does not appear to be significantly influenced by patient characteristics.

Biomaterial developments for bone tissue engineering.

The development of bone tissue engineering is directly related to changes in materials technology. While the inclusion of materials requirements is standard in the design process of engineered bone substitutes, it is also critical to incorporate clinical requirements in order to engineer a clinically relevant device. This review presents the clinical need for bone tissue-engineered alternatives to the present materials used in bone grafting techniques, a status report on clinically available bone tissue-engineering devices, and recent advances in biomaterials research. The discussion of ongoing research includes the current state of osseoactive factors and the delivery of these factors using bioceramics and absorbable biopolymers. Suggestions are also presented as to the desirable design features that would make an engineered device clinically effective.

Failure of exchange reamed intramedullary nails for ununited femoral shaft fractures.

OBJECTIVE: To determine the effectiveness of exchange reamed nails for treatment of aseptic femoral delayed unions and nonunions. DESIGN: Retrospective chart review. PATIENTS: Nineteen patients admitted to the Carolinas Medical Center Level I trauma center from 1990 to 1996 for repair of femoral shaft fracture nonunion following contemporary locked nailing performed at least six months previously. These patients showed no radiographic evidence of progression of fracture healing for three months and had clinical symptoms of nonunion. INTERVENTION: Exchange reamed nails to treat ununited femoral shaft fracture. MAIN OUTCOME MEASUREMENTS: Radiographic and clinical evidence of union of the fracture or of the necessity for additional procedures. RESULTS: In 53 percent of the patients the secondary procedure resulted in fracture union, whereas in 47 percent, one or more additional procedures were required. Eight of the nine fractures that did not unite with exchange nailing united after a subsequent procedure (bone grafting, compression plating, or nail dynamization). Neither the type of nonunion, the location of the shaft fracture, the use of static versus dynamic cross-locking, nor the use of tobacco products was statistically predictive of the need for additional procedures. CONCLUSIONS: Reevaluation of routine exchange nailing as the recommended treatment for aseptic femoral delayed union or nonunion may be required. A significant number of patients who undergo reamed exchange nailing will require additional procedures to achieve fracture healing.

Evaluation of standard surgical preparation performed on superficial dermal abrasions.

OBJECTIVES: To determine the difference, if any, between the reduction of bacteria on contaminated normal skin and contaminated superficially abraded skin following standard surgical preparations at clinically relevant time points after injury. DESIGN: Prospective animal study. SETTING: Laboratory. SUBJECTS: Thirty-two New Zealand white rabbits. INTERVENTION: Two sites, two by two centimeters, one abraded and one nonabraded (control), were studied on each rabbit. Both were inoculated with encapsulated Staphylococcus aureus strain Wood 46. Four six-millimeter punch biopsies were obtained after inoculation, immediately before surgical scrub, and five minutes and then two hours after completion of the surgical scrub. The rabbits were divided into four cohort groups with surgical scrubs performed at six, twelve, twenty-four, and forty-eight hours after inoculation. Bacterial counts were determined. MAIN OUTCOME MEASUREMENTS: Numbers of bacteria on surgical sites. RESULTS: Before surgical preparation, the amount of bacteria on the normal skin (control sites) dropped significantly (p<0.02) except in the six-hour group (p<0.20). At the abraded skin sites, the bacteria flourished. The surgical scrub dropped bacterial counts at both the abraded and nonabraded skin sites significantly (p<0.05) except for the abraded site in the twenty-four-hour group (p<0.08). However in the twelve-, twenty-four-, and forty-eight-hour groups, the bacterial counts (colony-forming units) were still markedly elevated (>1x10(5) at abraded sites) when compared with the nonabraded skin sites (p<0.008) at the respective time intervals. Only at the six-hour interval were the bacterial counts reduced similarly at both the abraded and nonabraded skin sites. CONCLUSIONS: In a rabbit model the standard surgical preparation using povidone-iodine at six hours after inoculation is effective in reducing the bacterial count on abraded skin to that of surgically prepared nonabraded skin. Beyond that time, the standard surgical preparation is ineffective in reducing counts to those of nonabraded skin at similar time intervals.

In vivo internalization of Staphylococcus aureus by embryonic chick osteoblasts.

Staphlylococcus aureus is the primary pathogen associated with osteomyelitis, an acute and recurrent bone disease. Internalization of S. aureus by cultured embryonic chick calvarial osteoblasts has been observed. The purpose of this study was to demonstrate that internalization of bacteria by embryonic chick calvarial and tibial osteoblasts occurs in vivo. In initial experiments, 10(8) colony forming units (cfu) of S. aureus, strain UAMS-1 or Cowan 1, were injected subcutaneously under the scalp skin of 17 day chick embryos. After 45 min, calvariae were harvested and processed for transmission electron microscopy (TEM). In subsequent experiments, 10(9) cfu of UAMS-1 were injected into the allantoic sac of 17 day chick embryos via a small opening in the egg shell. After 48 h, calvariae and tibiae were harvested for TEM. S. aureus cells were found in approximately 14% of the calvarial osteoblasts after subcutaneous injection and in 11% of calvarial and tibial osteoblasts following intraallantoic injection. Endosomes were observed in some cells, but most bacteria internalized appeared to be free in the cytoplasm. Osteoblasts with as few as five bacteria had a greater loss of cytoplasmic integrity and a more heterochromatic nucleus than osteoblasts with fewer bacteria or than uninfected osteoblasts. S. aureus cells in calvariae and tibiae were also observed in the cytoplasm of approximately 4% of the osteocytes in mineralized bone matrix. Thus, internalization of S. aureus by osteoblasts in vivo augments the previous observation in vitro. This study has also shown that osteoblasts with few bacteria continue differentiating into osteocytes. Results of these experiments support the hypothesis that internalization of S. aureus by osteoblasts may play a role in the etiology of osteomyelitis.

Intraoperative fluoroscopy to evaluate fracture reduction and hardware placement during acetabular surgery.

OBJECTIVES: To evaluate use of intraoperative fluoroscopy during acetabular surgery to determine fracture reduction and accurate placement of screws. DESIGN: Retrospective. SETTING: Level I trauma center. PARTICIPANTS: Thirty patients with thirty-two acetabular fractures. INTERVENTION: Patients were evaluated with fluoroscopy during surgery to assess fracture reduction and screw placement. Anterior-posterior (AP), oblique, and lateral pelvic fluoroscopic images were obtained intraoperatively. Postoperative radiographs were used to verify fluoroscopic findings; computed tomography (CT) scans were used as the control to assess intraarticular screw placement. MAIN OUTCOME MEASUREMENTS: Radiographic and clinical assessment of fracture reduction and screw placement. RESULTS: Intraoperative fluoroscopy confirmed the extra-articular position of all screws evaluated. Postoperative CT scans confirmed the extra-articular placement of all screws assessed by fluoroscopy. Quality of reduction using intraoperative fluoroscopic images had a 100 percent correlation with reduction on final radiographs. One patient, with two screws placed without fluoroscopic evaluation, had intra-articular placement requiring revision surgery. CONCLUSIONS: Intraoperative fluoroscopy is effective in evaluating both acetabular fracture reduction and hardware placement.

Mechanisms of Staphylococcus aureus invasion of cultured osteoblasts.

Staphylococcus aureus is a bacterial pathogen causing approximately 80% of all cases of human osteomyelitis. This bacterium can adhere to and become internalized by osteoblasts and previous studies indicate that osteoblasts are active in the internalization process. In the current study, we examined the roles of microfilaments, microtubules and clathrin-dependent receptor-mediated endocytosis in the internalization of S. aureus by MC3T3-E1 mouse osteoblast cells. Microfilament and microtubule polymerization was inhibited with cytochalasin D and colchicine. Clathrin-coated pit formation was examined by using the transaminase inhibitor, monodanslycadaverine. The results of this study indicate that mouse osteoblasts utilize actin microfilaments, microtubules and clathrin-coated pits in the internalization of S. aureus; however, microfilaments seem to play the most significant role in the invasion process.

Pulmonary gas exchange during intramedullary fixation of femoral shaft fractures.

BACKGROUND: This study was undertaken to determine if the alveolar dead space fraction (Vd/Vt) or the alveolar-arterial oxygen gradient (A-a DO2) increased during intramedullary fixation of femoral shaft fractures. METHODS: Fifty hemodynamically stable patients with femur fractures were prospectively enrolled. Three serial measurements of Vd/Vt and A-a DO2 were obtained immediately before femoral nailing (Pre), 30 minutes after nailing (+30), and 120 minutes after nailing (+120). Vd/Vt was determined by simultaneously measuring PaCO2 and the steady-state end-tidal CO2 (PetCO2), where Vd/Vt = (1 - PetCO2/PaCO2). RESULTS: Vd/Vt before nailing was 0.09 +/- 0.09 (mean +/- SD); at +30 and +120, Vd/Vt was 0.10 +/- 0.06 and 0.08 +/- 0.07, respectively (p > 0.2; paired t test, both time points). A-a DO2 before nailing was 84 +/- 85 mm Hg, and it did not change significantly at +30 (89 +/- 69 mm Hg; p = 0.51 vs. Pre; paired t-test) or at +120 (51 +/- 45 mm Hg). No difference in data was found with analysis by fracture classification or number of reamer passes. Vd/Vt and A-a DO2, however, were both significantly increased in patients with lung contusion (n = 6) before nailing, but neither measurement increased after nailing. One patient developed fat embolism (Vd/Vt of 0.35 at Pre and 0.31 at +120), and another patient experienced postoperative pulmonary thromboembolism (Vd/Vt increased from 0.06 at Pre to 0.17 at +120). CONCLUSION: The process of femoral nailing does not cause enough pulmonary embolization to alter pulmonary gas exchange as measured by Vd/Vt and A-a DO2. If Vd/Vt is increased preoperatively, the likelihood of subsequent pulmonary dysfunction secondary to either preoperative lung injury or fat embolism is increased.

Pelvic ring injuries.

Major pelvic disruptions lead to significant problems in acute resuscitation and definitive management. An understanding of the injury--its assessment and treatment principles--are necessary for appropriate management by all orthopaedic surgeons. In this article, we summarize the pelvic ring session at the Southeast Fracture Symposium.

Comparison of mechanical loads produced by current intramedullary reamer systems.

OBJECTIVE: This study evaluated the mechanical loading experienced by four clinically used intramedullary reamer cutter designs to evaluate the effects of variations in speed and feed rate on reamer system performance. DESIGN: Biomechanical laboratory study. SETTING: Research laboratory. MAIN OUTCOME MEASURE: Four clinically used reamer systems with detachable cutters were tested using a computer-controlled machining system at representative reaming and drilling speeds of 250 and 750 revolutions per minute (RPM), respectively. Hard oak blocks with mechanical properties similar to cortical bone were reamed using cutter heads with diameters from nine to fourteen millimeters (in 0.5-millimeter increments) at feed rates of 1.0 and 7.6 centimeters per second. Reactive axial loads and torques were recorded and analyzed. RESULTS: All systems demonstrated reduced maximal loads/torques for small reamer sizes (9 to 10.5 millimeters) at drilling speeds rather than reaming speeds. Individual systems demonstrated measurable differences in sensitivity to alterations in operating speed, indicating that some designs are not amenable to operation at increased speeds. In tests where reamer head cutting characteristics were isolated by using identical solid drive shafts, the deeply fluted design with a long lead taper and a rounded, burrlike body consistently produced significantly lower mechanical loading at all speeds and feed rates. In addition, two of the four systems tested use a larger flex shaft diameter for reamer head sizes of thirteen millimeters or greater. There was no indication of a need to use larger flex shafts for the larger reamers, based on mechanical load/torque data for those systems. CONCLUSIONS: The tests performed demonstrate that appropriate control of reaming speeds (RPM) can be used to minimize mechanical loading for all systems. Caution should be exercised, however, so that any operational changes that reduce resistive loads and torques do not lead the surgeon to increased feed rates. Additional study is required to investigate the variable effects of increasing the operating speed of each system on localized thermal changes.

Efficacy of surgical wound drainage in orthopaedic trauma patients: a randomized prospective trial.

OBJECTIVE: To study the efficacy of closed suction drainage in clean nonemergent surgical fracture fixation or bone grafting on the extremities or pelvis. DESIGN: A prospective randomized trial. SETTING: The orthopaedic trauma service of a Level I trauma hospital. PATIENTS: Patients were older than age eighteen years and undergoing clean nonemergent surgical fracture fixation or bone grafting procedures on the extremities (excluding hands and feet) or pelvis. INTERVENTION: The application of a surgical drain. MAIN OUTCOME MEASUREMENTS: Wound drainage, edema, hematoma and erythema, dehiscence, infection, and need for surgery or readmission were followed for six weeks. A univariate analysis with Student's t test for continuous variables and chi-squared analysis for all categorical data were used, with a p value of < or = 0.05 considered statistically significant. RESULTS: A total of 202 patients were randomized to 102 patients with no drain and 100 patients with a drain. There was no significant difference between the groups with regard to injury severity, systemic disease, age, body weight, physical status, or estimated blood loss. There was no significant difference between the drain and no-drain groups in any of the parameters evaluated. CONCLUSION: There is no significant difference between drained and nondrained wounds in clean, nonurgent orthopaedic trauma surgery. It appears that drainage systems can be safely eliminated in this group.

Does bacteremia occur during high pressure lavage of contaminated wounds?

The risk of bacteremia secondary to high pressure lavage of contaminated wounds was assessed. Twenty canines were divided randomly into four treatment groups. A 10-cm incision was made over the left shoulder of each dog. The deltoideus muscle was disrupted and traumatized. Groups A and B (n = 8) had wound contamination with 1.4 x 10(9) Staphylococcus aureus followed 75 minutes later by high pressure lavage or bulb syringe irrigation, respectively. Groups C and D (n = 2) had no contamination, followed by the same treatment. Bacterial counts were obtained before and after wound irrigation. Blood cultures were obtained before, during, and 15 minutes after irrigation. Positive control cultures were obtained during injection of bacteria into the antecubital vein. A detectable bacteremia did not occur during or after high pressure lavage or bulb syringe irrigation of acute contaminated wounds but did occur in 18 of 20 positive controls. Bacterial levels were reduced by an average of 70% +/- 10% by high pressure lavage and 44% +/- 50% by bulb irrigation. Reduction of wound bacteria was achieved more consistently with high pressure lavage than with bulb syringe irrigation.