Src is a major signaling component for CTGF induction by TGF-beta1 in osteoblasts.

Connective tissue growth factor (CTGF/CCN2) is induced by transforming growth factor beta1 (TGF-beta1) where it acts as a downstream mediator of TGF-beta1 induced matrix production in osteoblasts. We have shown the requirement of Src, Erk, and Smad signaling for CTGF induction by TGF-beta1 in osteoblasts; however, the potential interaction among these signaling pathways remains undetermined. In this study we demonstrate that TGF-beta1 activates Src kinase in ROS17/2.8 cells and that treatment with the Src family kinase inhibitor PP2 prevents Src activation and CTGF induction by TGF-beta1. Additionally, inhibiting Src activation prevented Erk activation, Smads 2 and 3 activation and nuclear translocation by TGF-beta1, demonstrating that Src is an essential upstream signaling partner of both Erk and Smads in osteoblasts. MAPKs such as Erk can modulate the Smad pathway directly by mediating the phosphorylation of Smads or indirectly through activation/inactivation of required nuclear co-activators that mediate Smad DNA binding. When we treated cells with the Erk inhibitor, PD98059, it inhibited TGF-beta1-induced CTGF protein expression but had no effect on Src activation, Smad activation or Smad nuclear translocation. However PD98059 impaired transcriptional complex formation on the Smad binding element (SBE) of the CTGF promoter, demonstrating that Erk activation was required for SBE transactivation. These data demonstrate that Src is an essential upstream signaling transducer of Erk and Smad signaling with respect to TGF-beta1 in osteoblasts and that Smads and Erk function independently but are both essential for forming a transcriptionally active complex on the CTGF promoter in osteoblasts.

Molecular requirements for induction of CTGF expression by TGF-beta1 in primary osteoblasts.

Connective tissue growth factor (CTGF/CCN2) is a cysteine rich, extracellular matrix protein that acts as an anabolic growth factor to regulate osteoblast differentiation and function. In osteoblasts, CTGF is induced by TGF-beta1 where it acts as a downstream mediator of TGF-beta1 induced matrix production. The molecular mechanisms that control CTGF induction by TGF-beta1 in osteoblasts are not known. To assess the role of individual Smads in mediating the induction of CTGF by TGF-beta1, we used specific Smad siRNAs to block Smad expression. These studies demonstrated that Smads 3 and 4, but not Smad 2, are required for TGF-beta1 induced CTGF promoter activity and expression in osteoblasts. Since the activation of MAPKs (Erk, Jnk and p38) by TGF-beta1 is cell type specific, we were interested in determining the role of individual MAPKs in TGF-beta1 induction of CTGF promoter activity and expression. Using dominant negative (DN) mutants for Erk, Jnk and p38, we demonstrated that the expression of DN-Erk caused a significant inhibition of TGF-beta1 induced CTGF promoter activity. In contrast, the expression of DN-p38 or DN-Jnk failed to inhibit activation of CTGF promoter activity. To confirm the vital role of Erk, we used the Erk inhibitor (PD98059) to block its activation, demonstrating that it prevented TGF-beta1 activation of the CTGF promoter and up-regulation of CTGF expression in osteoblasts. Since Src can also act as a downstream signaling effector for TGF-beta in some cell types, we determined its role in TGF-beta1 induction of CTGF in osteoblasts. Treatment of osteoblasts with a Src family kinase inhibitor, PP2, or the expression of two independent kinase-dead Src mutant constructs caused significant inhibition of TGF-beta1 induced CTGF promoter activity and expression. Additionally, blocking Src activation prevented Erk activation by TGF-beta1 demonstrating a role for Src as an upstream mediator of Erk in regulating CTGF expression in osteoblasts. To investigate the involvement of the TGF-beta1 response element (TRE) and the SMAD binding element (SBE) in CTGF induction, we cloned the rat CTGF proximal promoter (-787 to +1) containing the TRE and SBE motifs into a pGL3-Luciferase reporter construct. Using a combination of CTGF promoter deletion constructs and site-directed mutants, we demonstrated the unique requirement of both the TRE and SBE for CTGF induction by TGF-beta1 in osteoblasts. Electro-mobility shift assays using specific probes containing the TRE, SBE or both showed TGF-beta1 inducible complexes that can be ablated by mutation of the respective motif, confirming their requirement for TGF-beta1 induced CTGF promoter activity. In conclusion, these studies demonstrate that CTGF induction by TGF-beta1 in osteoblasts involves Smads 3 and 4, the Erk and Src signaling pathways, and requires both the TRE and SBE motifs in the CTGF proximal promoter.

Orthopaedic trauma education: visions for the future through the OTA. Orthopaedic Trauma Association.

As the trauma center system continues to expand, not only will the requirement for more and better trained trauma surgeons increase, but the means of educating them will need to become more standardized. The general surgeons recognized this many years ago, but orthopaedic trauma has lagged in its efforts to present a coordinated academic and clinical program to residents and fellows. The Orthopaedic Trauma Association has made a move to develop guidelines which may be used by training programs in an effort to improve the educational standards of this subspecialty. The recruitment and retention of young orthopaedic trauma surgeons remains an issue.

Aggressive treatment of 119 open fracture wounds.

BACKGROUND: The purpose of this study was to determine whether immediate primary closure of open fracture wounds can be performed without increasing the incidence of infections and delayed unions/nonunions. Although the traditional management of these injuries has been open treatment, a trend toward immediate primary closure has evolved on our service. METHODS: All open fractures presenting to an urban Level I trauma center during a 42-month period were reviewed. Of the 127 patients with open fractures, 90 patients (119 open fractures) were initially treated at the above institution within 24 hours of injury, had fractures proximal to the carpus or tarsals, and were followed-up until fracture union. All patients underwent emergent wound irrigation and debridement. The method of fracture immobilization and timing of wound closure was left to the discretion of the attending orthopedic surgeon. Immediate primary closure was used in 22 of 25 Grade I open fractures (88%), 37 of 43 Grade II fractures (86%), 24 of 32 Grade IIIa fractures (75%), 4 of 12 Grade IIIb fractures (33%), and 0 of 7 Grade IIIc fractures (0%). RESULTS: Eight fractures (7%) were complicated by a deep wound infection/osteomyelitis, and 19 fractures (16%) developed a delayed union/nonunion. Statistical analysis revealed no significant difference in delayed/nonunion and infection rates between immediate and delayed closures. CONCLUSION: Immediate primary closure of open fracture wounds after a thorough debridement by an experienced fracture surgeon appears to cause no significant increase in infections or delayed union/nonunions. In addition, early closure may decrease the requirement for subsequent debridements and soft-tissue procedures, thereby minimizing surgical morbidity, shortening hospital stays, and reducing costs. We feel that a randomized, prospective study of this aggressive approach to open fracture care is warranted.

Diaphyseal forearm fractures treated with and without bone graft.

BACKGROUND: The purpose of this study was to determine whether the acute bone grafting of diaphyseal forearm fractures decreases the incidence of nonunion and reduces the time to union. Although the traditional treatment of comminuted radius and/or ulnar shaft fractures involves bone graft, a recent report called into question this practice. PATIENTS: A database search was used to identify all acute diaphyseal forearm fractures presenting to an urban Level I trauma center between 1988 and 1996. All radius and/or ulnar shaft fractures, as well as all Monteggia and Galeazzi fracture-dislocations, in patients with closed physes were included. The charts and operative reports were available for 64 diaphyseal forearm fractures in 49 patients. Fifty-six fractures were followed for at least 1 year beyond clinical and radiographic union. The injuries were treated with open reduction and plate fixation by experienced orthopedic traumatologists. All noncomminuted fractures were treated without bone graft. For the comminuted fractures, the decision to use bone graft was left to the discretion of the operating surgeon. RESULTS: Overall, 55 of 56 fractures (98%) achieved union at a mean of 49 days (range, 19-123 days), with the only nonunion occurring in a patient with a closed, noncomminuted Galeazzi injury. Among the 20 noncomminuted fractures, all of which were treated without bone graft, 19 (95%) achieved union at a mean of 50 days (range, 19-102 days). Among the 36 comminuted fractures, all 25 treated without bone graft achieved fusion at an average of 50 days (range, 20-123 days) and all 11 treated with bone graft achieved union at an average of 45 days (range, 22-67 days). No statistically significant difference in the incidence of nonunion or time to union was noted between fractures that were treated with and without bone graft. CONCLUSION: Acute bone grafting of diaphyseal forearm fractures did not affect the union rate or the time to union.

Role of in situ IL-2r and TGF-beta expression in tolerant vascularized bone marrow (limb) transplant chimeras.

We hypothesized that an increase in IL-2 activated T cells in situ within the marrow component of a transplanted limb may adversely affect development of tolerance, while increased TGF-beta expression locally would facilitate tolerance induction and/or maintenance. Digital image analysis of cellular expression of IL-2r in the bone marrow was significantly increased in the CON and TXP limbs for both GVHD and tolerant recipients as compared to normal limb marrow (P < .02). The amount of cellular expression of TGF-beta was significantly increased in the GVHD animals, both CON and TXP, as compared to the tolerant animals (43.2 +/- 3.1 vs 10.6 +/- 2.6; P < .000001). Our results show that increased IL-2r and TGF-beta expression in situ within the bone marrow is an important effect common to both alloimmune tolerance and GVHD induction with VBMT chimeras. The dramatic increase in the expression of TGF-beta in the GVHD transplanted limbs may explain the profound immunosuppression that results. Additionally, moderate expression of TGF-beta in situ in tolerant chimeras may represent a mechanism for the induction and maintenance of tolerance.

Graft-versus-host disease in limb transplantation: digital image analysis of bone marrow and TGF-beta expression in situ using a novel 3-D microscope.

A subpopulation of parental to hybrid VBMT recipients developed characteristic clinical and histopathologic manifestations of GVHD. These changes are similar to those seen in human GVHD secondary to bone marrow transplantation. Human GVHD also manifests itself in an acute and chronic manner. Only a minority (30% to 40%) of animals developed lethal GVHD in our model. Those animals developing GVHD had a significantly (P < .0001) higher expression of TGF-beta in situ compared to the tolerant subpopulation. The differential expression of TGF-beta may represent an important mechanism of immune dysregulation associated with GVHD in CTA recipients.

Surgical management of soft tissue lesions associated with pelvic ring injury.

Mortality rates associated with pelvic ring injury combined with open wounds have decreased considerably during the past 2 decades. Consequently, increased survivability has heightened the demand for definitive stabilization techniques to address pelvic ring instability. Control of hemorrhage and avoidance of sepsis remain paramount concerns in the initial and later stages of management, respectively. Exclusion of occult and readily apparent perforations of the genital urinary and gastrointestinal tracts is essential when using a multidisciplinary approach. Recognition of open and closed degloving injury patterns and appropriate adherence to treatment guidelines will optimize outcome and avoid catastrophic complication.

Patterns of injury and disability caused by forklift trucks.

Over a 7-year period, 34 patients were treated at the Southern New Jersey Regional Trauma Center for forklift-related injuries, ranging from minor contusions to multiple organ-system trauma. Hospital and rehabilitation courses were prospectively evaluated, documenting long term impairment of function and disability. Patients injured by falling from forklifts generally had less severe injuries, requiring fewer surgical procedures, shorter hospital stays, and less overall disability, than patients who received crush-type (object-oriented) injuries. The more serious injuries were most frequently caused by a forklift striking or running over the patient. There were strong correlations between the Injury Severity Score assessed upon initial evaluation and subsequent length of hospitalization, degree of disability, and extent of functional impairment after recovery. These findings support the enforcement of existing safety precautions for the operation of forklift trucks.

Open fractures of the patella: long-term functional outcome.

Seventy-nine open patella fractures in 76 patients were treated between 1986 through 1994, with an 80% incidence of multiple injuries. All were treated with irrigation and debridement, open reduction, internal fixation, and reconstruction of the extensor mechanism. In no case was a primary patellectomy performed, even with severe comminution. There were three failures of initial fixation and one asymptomatic nonunion. Average range of motion for all groups was 112 degrees, at an average follow-up of 21 months. Secondary surgical procedures were performed in 65% of knees, the majority for symptomatic hardware. To determine long-term functional outcome, a modified Hospital for Special Surgery knee score was used. At an average of 36 months, good to excellent knee scores were observed in 17 of 22 patients. We conclude that all attempts for preservation of bone substance and precise reconstruction of the extensor should be attempted, reserving total patellectomy as a salvage procedure.

Graft-versus-host disease in extremity transplantation: digital image analysis of bone marrow in situ.

The development of either unstable immune chimerism and lethal graft-versus-host disease or stable immune chimerism and alloimmune tolerance can result from extremity transplantation. LBN rats served as recipients of Lewis vascularized extremity (limb) transplants. Recipients received no immune suppression and were immunologically unmodified. The bone marrow of transplanted and contralateral limbs was analyzed in situ for distribution of nuclei, nuclear area, and staining intensity by digital image analysis and computerized morphometry. Cellularity was significantly increased, and fat content was significantly decreased in the graft-versus-host disease animals' marrow versus the tolerant animals' marrow for both the transplanted and contralateral limbs. Tolerant animals demonstrated significantly increased nuclear staining compared with graft-versus-host disease animals for both transplanted and contralateral limbs. Additionally, there were significant changes between the host and the transplanted limbs for marrow intensity and cellularity within tolerant and graft-versus-host disease groups. The significant differences in the graft-versus-host disease-positive recipients suggested that both autoimmune dysregulation and alloimmune reactions were in effect for both donor and host bone marrow compartments. Cellular alterations in the tolerant recipients' marrow were suggestive of subtle subclinical graft-versus-host responses.

Early exchange intramedullary nailing of distal femoral fractures with vascular injury initially stabilized with external fixation.

Fracture of the femur with accompanying arterial injury represents approximately 1% of all femoral fractures. Controversy exists regarding the choice of fixation and the sequence of fixation and vascular repair. We report on the treatment of six patients with seven distal femoral fractures and angiographically documented arterial injuries treated over a 20-month period. The treatment protocol consisted of angiography followed by provisional external fixation and early primary exchange to an intramedullary nail. Five of the seven fractures were open. Three fractures were caused by blunt trauma, and four were secondary to shotgun blasts. Average follow-up was 12 months (range, 6-25 months). All fractures healed with an average time to union of 25 weeks. There were no complications related to the vascular repair. One case of an acute deep infection resolved after debridement and placement of polymethylmethacrylate cement beads impregnated with antibiotics and a course of intravenous antibiotics. All patients returned to their previous levels of activity. Based on the results of our experience with a small group of patients, we feel that this treatment protocol will prove to be a safe and efficient method of management of these difficult injuries.

Initial experience with the treatment of supracondylar femoral fractures using the supracondylar intramedullary nail: a preliminary report.

Initial experience at a Level I Trauma Center with the use of a retrograde supracondylar intramedullary (IM) nail for the treatment of supracondylar and supracondylar-intercondylar intraarticular fractures of the distal femur is presented. Thirty-eight patients with 41 complex distal femur fractures were treated with this newly developed retrograde IM rod. These included 22 open fractures and 19 closed fractures. Four nonunions occurred, but all progressed to union after revision internal fixation and bone grafting. Two of five delayed unions required revision fixation. Two required screw renewal and dynamization. Thirty-five of 41 knees achieved at least 90 degrees of knee motion. There were no infections and no problems with wound healing. Four patients developed fatigue fractures of the rod. These mechanical failures occurred when 11- and 12-mm nails were used in conjunction with 6.4-mm interlocking screws. The rod system was therefore modified to include 12- and 13-mm diameter nails and smaller 5.0-mm interlocking screws. There have been no subsequent nail failures. We are cautiously optimistic that supracondylar IM rod fixation will contribute to the management of these difficult fractures. However, further clinical trials and additional biomechanical testing should be undertaken prior to widespread use of this device.

Three-dimensional computerized tomographic demonstration of bilateral atlantoaxial rotatory dislocation in an adult: report of a case and review of the literature.

A rare case of bilateral atlantoaxial rotatory dislocation (Fielding type V) in an adult is presented. The diagnosis was rapidly made by computed axial tomography. Prior reports of this entity have not clearly defined the pathoanatomy, which in our case was confirmed by three-dimensional tomographic reconstruction. We offer a clarification of the anatomic lesion and a discussion of this injury, which may make recognition and treatment of future cases easier.

Clinical predictors of unstable cervical spinal injury in multiply injured patients.

All victims of major blunt trauma have been said to be at risk of cervical spinal injury. In a prospective study of 410 such patients at our institution, we identified 13 patients (6.12 per cent) with unstable cervical spines. Loss or defect of consciousness following injury (regardless of duration), neurological deficit consistent with cervical cord or nerve root injury and neck tenderness were significantly predictive of an unstable cervical spine. Immediate radiographic investigation of the cervical spine is mandatory in such patients, but may not be required in patients without these signs.

Dynamic computerized tomography of the occiput-atlas-axis complex in trauma patients with odontoid lateral mass asymmetry.

Over a 23-month period, 25 patients aged 11 to 74 years presented to our Level I trauma center with odontoid lateral mass asymmetry of 2 to 5 mm on properly centered AP open-mouth X-rays: 32% of patients were asymptomatic, 68% had cervical pain, and 32% had limited range of motion. Patients with cervical spine fractures or dislocations and those with fixed deformity were excluded. The clinical significance of asymmetry was determined utilizing dynamic axial CT scanning of the occiput (C0), atlas (C1) and axis (C2) with the head neutral and with 15 degrees to 30 degrees active rotation. Nineteen patients demonstrated greater than 5 degrees of relative motion of C1 on C2 bilaterally. Three patients had less than 5 degrees of relative motion bilaterally and three patients had less than 5 degrees relative motion with left rotation only. No patient had formal treatment and all had nearly normal cervical range of motion on clinical examination at the time of hospital discharge. The finding of an asymmetric odontoid-lateral mass interspace on properly centered open-mouth AP X-rays in the presence of otherwise normal cervical spine X-rays, in conscious patients without fixed deformity, appears to be incidental and requires no further evaluation or treatment.

Interpretation of the cervical spine X-ray: a simplified approach.

Because many nursing interventions require mobilization of the patient, cervical spine film interpretation should be a necessary tool of the critical care nurse. This article provides the fundamentals necessary for initial interpretation of the cervical spine, plus a review of the common radiographic views of the cervical spine, abnormalities, and a systematic approach to the interpretation of these studies.

Delayed identification of skeletal injury in multisystem trauma: the 'missed' fracture.

Delay in diagnosis of musculoskeletal injury in multiply injured patients may potentially lead to functional or cosmetic disability in survivors. In an 18-month prospective study to determine the incidence and spectrum of delayed recognition of skeletal injury at our Level I trauma center, delayed diagnosis of 39 fractures was made in 26 of 1,006 consecutive blunt trauma patients. The delay in recognition ranged from 1-91 days. Twenty-one (55%) of the fractures were not X-rayed at the time of admission, but nine (23%) fractures were clearly visible on admission films. Four (10%) fractures were missed because of technically inadequate X-rays, and five (13%) had adequate X-rays but could not be identified on admission films. In only two instances was a second anesthetic exposure required for operative therapy. For the patients in this series, the delay of fracture identification was not felt to contribute to additional long-term cosmetic, functional, or neurologic problems. Continued clinical and radiologic surveillance is required in multiply injured patients to prevent musculoskeletal diagnostic failure.

Abdominal trauma associated with pelvic fractures.

Abdominal trauma should always be suspected with major pelvic fractures until proven otherwise. Thorough assessment and diagnostic evaluation will determine whether surgical management is necessary. Nursing care continues to the postinjury period, which needs close observation because further complications are common.