Charles M. Reinert

Effect of Recombinant Human Bone Morphogenetic Protein‐2 on Fracture Healing in a Goat Tibial Fracture Model

Bone morphogenetic proteins (BMPs) are considered to have important regulatory roles in skeletal embryogenesis and bone healing. Recombinant human BMPs (rhBMPs) have been shown to heal critical size defects and promote spinal fusion. We studied the effects of rhBMP‐2 in an absorbable collagen sponge (ACS) on bone healing in a large animal tibial fracture model. Bilateral closed tibial fractures were created in 16 skeletally mature goats and reduced and stabilized using external fixation. In each animal, one tibia received the study device (0.86 mg of rhBMP‐2/ACS or buffer/ACS), and the contralateral fracture served as control. The device was implanted as a folded onlay or wrapped circumferentially around the fracture. Six weeks following fracture, the animals were sacrificed and the tibiae harvested for torsional testing and histomorphologic evaluation. Radiographs indicated increased callus at 3 weeks in the rhBMP‐2/ACS treated tibiae. At 6 weeks, the rhBMP‐2/ACS wrapped fractures had superior radiographic healing scores compared with buffer groups and controls. The rhBMP‐2/ACS produced a significant increase in torsional toughness (p = 0.02), and trends of increased torsional strength and stiffness (p = 0.09) compared with fracture controls. The device placed in a wrapped fashion around the fracture produced significantly tougher callus (p = 0.02) compared with the onlay application. Total callus new bone volume was significantly increased (p = 0.02) in the rhBMP‐2/ACS fractures compared with buffer groups and controls regardless of the method of device application. The rhBMP‐2/ACS did not alter the timing of onset of periosteal/endosteal callus formation compared with controls. Neither the mineral apposition rates nor bone formation rates were affected by rhBMP‐2/ACS treatment. The increased callus volume associated with rhBMP‐2 treatment produced only moderate increases in strength and stiffness.

Pelvic ring disruptions: Prediction of associated injuries, transfusion requirement, pelvic arteriography, complications, and mortality

Objective To determine if age, fracture pattern, systolic blood pressure on arrival, base deficit, or the Revised Trauma Score is predictive of mortality, transfusion requirements, use of pelvic arteriography, later complications, or injuries associated with the pelvic ring disruption. Study Design Retrospective review of a prospectively collected database. Methods All closed pelvic ring disruptions seen between November 1, 1997 and November 30, 1999 were included. Predictive variables and outcome variables were recorded for each patient. Statistical analysis was used to determine if the above variables were predictive. Results Shock on arrival and the Revised Trauma Score were significantly associated with mortality, transfusion requirement, Injury Severity Score, and all the Abbreviated Injury Scores except the one for skin. In addition, the Revised Trauma Score was significantly associated with the use of pelvic arteriography and predicted more complications than did shock on arrival. Age was significantly associated with transfusion requirement, Injury Severity Score, the chest and skin Abbreviated Injury Scores, use of arteriography, and death. The mortality rate among patients who presented in shock was 57 percent. A Revised Trauma Score of less than 11 predicted mortality with a sensitivity and specificity of 58 percent and 92 percent, respectively. Shock on arrival predicted mortality with a sensitivity and specificity of 27 percent and 96 percent, respectively. Age greater than sixty years predicted mortality with a sensitivity and specificity of 26 percent and 91 percent, respectively. In our analysis of the fracture patterns, we were unable to demonstrate consistent, meaningful links between specific fracture classes and the outcome variables. Conclusions Shock on arrival and the Revised Trauma Score are useful predictors of mortality and transfusion requirements, Injury Severity Score, and Abbreviated Injury Scores for the head and neck, face, chest, abdomen, and extremities. In addition, the Revised Trauma Score predicts the use of pelvic arteriography and later complications. Age predicted transfusion requirement, Injury Severity Score, the chest and skin Abbreviated Injury Scores, use of arteriography, and death.

Vertically unstable pelvic fractures fixed with percutaneous iliosacral screws: does posterior injury pattern predict fixation failure?

Objective To measure the failure rate of percutaneous iliosacral screw fixation of vertically unstable pelvic fractures and particularly to test the hypothesis that fixations in which the posterior injury is a vertical fracture of the sacrum are more likely to fail than fixations with dislocations or fracture-dislocations of the sacroiliac joint. Design Retrospective review. Setting Level 1 trauma center. Methods All patients with pelvic fractures admitted between January 1, 1993, and December 31, 1998, were identified from the trauma registry. Hospital records were used to identify patients treated with iliosacral screws. Radiologic studies were examined to identify patients who had unequivocally vertically unstable pelvic fractures. Immediate postoperative and follow-up anteroposterior, inlet, and outlet radiographs from a minimum of 12 months postinjury were examined. Position, length, and numbers of iliosacral screws and any evidence of screw failure (eg, bending or breakage) were recorded. Residual postoperative displacement and late displacement of the posterior pelvis were measured. The main outcome measure was failure, defined as at least 1cm of combined vertical displacement of the posterior pelvis compared with immediate postoperative position. The main analysis was for association between fracture pattern and failure. Patient demographic data, iliosacral screw position, and anterior pelvic fixation method also were studied. Results The study group comprised 62 patients with unequivocally vertically unstable pelvic fractures in whom the posterior injury was treated with closed reduction and percutaneous iliosacral screw fixation. Of patients, 32 had dislocations or fracture-dislocations of the sacroiliac joint, and 30 had vertical fractures of the sacrum. Fixation failed in four patients, all with vertical sacral fractures and all within the first 3 weeks after surgery. These four patients required revision fixation. In two further cases with vertical sacral fractures, there was evidence that the fracture had only barely been held by the fixation, but these fractures healed, and follow-up radiographs did not meet the displacement criteria for failure. A vertical sacral fracture pattern was associated significantly with failure (Fisher exact test, P =0.04); the excess risk of failure compared with sacroiliac joint injury was 13% (95% confidence interval 1% to 25%). There was no significant association between failure and anterior fixation method, iliosacral screw arrangement or length, or any demographic or injury variable. Conclusions Percutaneous iliosacral screw fixation is a useful technique in the management of vertically unstable pelvic fractures, but a vertical sacral fracture should make the surgeon more wary of fixation failure and loss of reduction.

Percutaneous fixation of the columns of the acetabulum: a new technique.

A technique for percutaneous placement of cannulated screws in the acetabulum is presented. Surgical technique is described, and fluoroscopic imaging techniques used to guide screw placement are also illustrated. The technique was used to limit soft tissue dissection in three patients. Results and examples are presented.

Preliminary results and complications following limited open reduction and percutaneous screw fixation of displaced fractures of the actabulum

Twenty-four patients underwent attempted closed or limited open reduction of displaced acetabular fractures. If reduction was successful, the fractures were stabilized with percutaneous screws. Group 1 was composed of elderly patients with complex fractures and radiographic findings that were felt to be predictive of post-traumatic arthritis. In these patients, percutaneous screw fixation was used to improve fracture anatomy, allow mobilization and total hip replacement later, if necessary. In group 1, anatomical reduction was not felt to be a necessity. Group 2 was composed of young patients with simple fracture types. For group 2, anatomical reduction was the goal. In 23/24 patients, closed or limited open reduction was successful. In group 1, maximum displacement averaged 10 mm preoperatively, 3 mm postoperatively. In group 2, maximum displacement averaged 7 mm preoperatively, 1 mm postoperatively. One elderly patient was lost to follow-up and one died, leaving 21 patients with an average follow-up of 12 months. All the fractures healed. One patient had a transient femoral nerve palsy, and two elderly patients had minor losses of reduction due to unprotected ambulation after surgery. Five of the elderly patients have gone on to total hip arthroplasty. The average Harris Hip scores in groups 1 and 2 were 85 and 96, respectively.

Percutaneous screw fixation of fractures of the iliac wing and fracture-dislocations of the sacro-iliac joint (OTA Types 61-B2.2 and 61-B2.3, or Young-Burgess "lateral compression type II" pelvic fractures).

A technique for closed reduction and percutaneous screw fixation of fractures of the iliac wing and fracture–dislocations of the sacro-iliac joint is presented. Twenty-seven pelvic fractures were treated with attempted closed reduction followed by percutaneous screw fixation. Closed reduction failed in two patients. In the other twenty-five, closed reduction to within one centimeter of residual displacement was obtained, and was followed by stabilization with percutaneously placed cannulated screws. Complications included dislodgment of a screw from the superior pubic ramus in one patient, and partial cut-out of a screw along the inner cortex of the iliac wing in another. Two patients were lost to follow-up before fracture union occurred. The remaining twenty-three patients were followed-up for an average of twenty-seven months (range, 18–48 months). All of the fractures healed in the twenty-three patients who were not lost to follow-up. All but two of the patients who were working before injury returned to work. All but one of the patients was satisfied with the outcome of their pelvic fracture treatment. Closed reduction and percutaneous screw fixation of fractures of the posterior portion of the iliac wing yields acceptable reductions, with minimal blood loss and limited damage to the surrounding soft tissues.

The effect of pelvic fracture on mortality after trauma: An analysis of 63,000 trauma patients

BACKGROUND The understanding of the mortality risk posed by pelvic fracture is incomplete. The purposes of this study were (1) to compare the mortality risk associated with a pelvic fracture with the risk conferred by other injuries and (2) to determine if the association of a pelvic fracture with mortality varies when combined with other known risk factors. METHODS Trauma registry records from two level-I trauma centers were examined. Regression analysis was done on 63,033 patients to assess the odds ratio for mortality associated with pelvic fracture compared with other variables such as age, shock, head injury, abdominal or chest injury, and extremity injury. A second analysis was carried out to determine if the impact of a pelvic fracture on mortality varied when combined with other known risk factors for mortality. RESULTS Logistic regression analysis demonstrated that pelvic fracture was significantly associated with mortality (p < 0.001). The odds ratio for mortality associated with a pelvic fracture (approximately 2) was similar to that posed by an abdominal injury. Hemodynamic shock, severe head injury, and an age of sixty years or more all had an odds ratio for mortality greater than that associated with pelvic fracture. CONCLUSIONS For the majority of trauma patients, pelvic fracture is significantly associated with a greater risk of mortality. However, pelvic fracture is one variable among many that contribute to mortality risk, and it must be considered in relation to these other variables.

Cephalomedullary nails in the treatment of high-energy proximal femur fractures in young patients: a prospective, randomized comparison of trochanteric versus piriformis fossa entry portal.

Objective The purpose of this study is to compare a cephalomedullary nail that uses a piriformis fossa starting point to one that uses a trochanteric starting point, in the treatment of high-energy proximal femur fractures in young patients. Our hypothesis was that a nail that uses a trochanteric starting point would result in less blood loss than a nail that uses a piriformis fossa starting point. Design Prospective, randomized. Setting Level 1 trauma center. Patients Thirty-four consecutive patients aged between 18 and 50 years who sustained a subtrochanteric, intertrochanteric, or ipsilateral femoral neck/shaft fracture due to a high-energy injury were enrolled. Intervention Patients were randomized to have their fractures repaired with a Russell-Taylor Recon Nail or Howmedica Long Gamma Nail. Surgery was performed on a fracture table, in supine or lateral position according to the surgeons preference. Direct fracture exposure was avoided. Reduction was obtained through traction, patient positioning, and manual pressure. If necessary, stab-wound incisions were made to introduce instruments to improve reduction. Intramedullary reamers were used, and all nails were statically locked. Bone grafting was not used. Main Outcome Measures Blood loss, incision length, duration of surgery, and body mass index were recorded for each patient. Surgeons assessment of ease of use of the device and quality of reduction were noted. Patients were to be followed up to assess fracture union. Hip and knee ranges of motion at latest follow-up were measured. Radiographs obtained at the time of union were assessed for varus malalignment. Return to work status was recorded, and the Harris Hip Score was used to assess hip function. Results There were 17 patients in each group. The 2 groups did not differ with regard to blood loss, incision length, and duration of surgery or intraoperative complications. Body mass index was significantly linked to duration of surgery (P<0.001) and incision length (P<0.001). Surgeons assessment of ease of use and reduction quality for the two devices did not differ. The rate of varus malunion did not differ between the 2 groups. Two patients were lost to follow-up before fracture union. All other fractures healed with no need for bone grafting or other procedures to obtain union. One obese patient developed a wound infection that resolved after debridement and a course of antibiotics. A total of 6 patients were lost prior to their 1-year follow-up visit. Among the remaining 28 patients, at an average follow-up of 14 months, no difference was noted between the 2 groups with regard to return to work status, Harris Hip Score, or hip and knee ranges of motion. Conclusions Both devices yield predictably good results in these difficult fractures. We found no difference between the two devices with regard to incision length, duration of surgery, blood loss, reduction, ease of use, union rate, complication rate, or outcome.

Treatment of femur fracture with associated vascular injury.

OBJECTIVE The aim of this study was to determine (1) if internal fixation was associated with a high amputation rate in patients with femur fracture and vascular injury; and (2) if patients who underwent internal fixation before vascular repair had a higher amputation rate. DESIGN This is a retrospective analysis. MATERIALS AND METHODS Twenty-six patients requiring femoral stabilization with injury to the superficial femoral artery, popliteal artery, or common femoral vein were studied. The Injury Severity Score and the Mangled Extremity Severity Score were calculated for each. Nineteen patients underwent internal fixation. Ten patients had internal fixation before vascular repair. RESULTS Sixteen of 19 patients treated with internal fixation had limb salvage. Nine of 10 patients who had internal fixation before vascular repair had limb salvage. Poor outcomes (gangrene, amputation, or death) were associated with a Mangled Extremity Severity Score > or = 6 (p = 0.005). CONCLUSIONS In these patients, poor outcome is associated with severe leg injury, (with a Mangled Extremity Severity Score of > or = 6). Internal fixation can be safely used, and skeletal stabilization can be safely performed before vascular repair. If ischemic time is prolonged, vascular shunts should be used until skeletal stabilization is completed.

Treatment of femur fracture with associated head injury.

OBJECTIVES The aim of this study was to determine (a) whether delay in femur fracture stabilization beyond twenty-four hours in patients with head injury increased the risk of pulmonary complications and (b) whether immediate (up to twenty-four hours) femur fracture stabilization increased the risk of central nervous system (CNS) complications. DESIGN Retrospective analysis. MATERIALS AND METHODS Thirty-two patients with femur fracture and head injury were identified. Fourteen underwent immediate stabilization of their fractures, and eighteen underwent delayed (four-teen patients) or no (four patients) stabilization of their fractures. RESULTS In the immediate stabilization group, five patients had severe head injuries [Glasgow Coma Score (GCS) < or = 8] and nine had mild head injuries (GCS > 8). In the mild head injury group, no patient had a pulmonary complication and one had a CNS complication. In the severely head-injured group, one patient had a pulmonary complication and no patient had a CNS complication. In the delayed stabilization group, six patients had mild head injuries (GCS > 8) and twelve had severe head injuries (GCS < or = 8). In the mildly head injured group, one patient had a pulmonary complication, two patients had CNS complications, and one patient died. In the severely head injured group, nine patients had pulmonary complications, three patients had CNS complications, and one patient died. Logistic regression identified delay in femur stabilization as the strongest predictor of pulmonary complication (p = 0.0042), followed by severity of chest Abbreviated Injury Score (AIS; p = 0.0057) and head AIS (p = 0.0133). Delaying fracture stabilization made pulmonary complications forty-five times more likely. Each point increase in the chest AIS and head/neck AIS increased the risk of pulmonary complication by 300 percent and 500 percent, respectively. A statistically significant predictor of CNS complications could not be identified by using logistic regression. CONCLUSION Delay in stabilization of femur fracture in head-injured patients appears to increase the risk of pulmonary complications. However, due to selection bias in this patient sample, this question cannot be definitively answered. Early fracture stabilization did not increase the prevalence of CNS complications.