Faculty Bibliography

Obesity has been increasing steadily in the US population over the past 50 years. In trauma patients, obesity is associated with higher morbidity and mortality. There are reported increases in the incidence of cardiovascular, pulmonary, venous thromboembolic, and infectious complications in obese trauma patients. Obese patients who sustain high-energy traumatic injuries often sustain orthopedic injuries to the pelvis or lower extremities. Obese orthopedic trauma patients may be at higher risk for nerve injuries secondary to positioning, intraoperative complications, loss of reduction after surgery, increased intraoperative estimated blood loss, and increased operative times. Orthopedic surgeons must be aware of these results when treating these fractures in obese trauma patients

OBJECTIVES: It is well recognized that operative treatment of a fracture of the distal humerus requires handling of the ulnar nerve, which can cause nerve dysfunction; however, the incidence of postoperative ulnar nerve dysfunction is not well studied. Our purpose was to determine the incidence of ulnar nerve dysfunction after open reduction and internal fixation of distal humerus fractures and identify factors associated with its development. DESIGN: Retrospective cohort study from two university-based institutions. PATIENTS: The medical records of 69 patients with a minimum of 12 months follow-up (median, 15 months; range, 12-72 months) after open reduction and plate and screw fixation of a bicolumnar fracture of the distal humerus (Orthopaedic Trauma Association Types 13A and C) that did not have preoperative ulnar nerve dysfunction were reviewed retrospectively. INTERVENTION: Surgical repair of a distal humerus fracture with or without ulnar nerve transposition. MAIN OUTCOMES: Ulnar nerve function was graded immediately postoperatively and at final follow-up according to a modified system of McGowan. Those with and without ulnar neuropathy were analyzed for differences in final position of the nerve (anterior versus in the cubital tunnel), open injury, multiple procedures, ipsilateral injury, and demographic factors. RESULTS:: The incidence of immediately postoperative ulnar nerve dysfunction documented in the medical record was seven of 69 patients (10.1%) (McGowan grades: 1 [57%], 2 [43%], 3 [0%]). The incidence of ulnar nerve dysfunction at final follow-up was 16% (11 of 69 patients) (McGowan grades: 1 [72%], 2 [28%], 3 [0%]). No demographic, injury, or treatment factors were associated with a risk of postoperative ulnar nerve dysfunction. CONCLUSION: There is a substantial incidence of postoperative ulnar nerve dysfunction after open reduction and plate and screw fixation of the distal humerus, which is likely underestimated by this retrospective analysis. Prospective studies using careful preoperative nerve evaluation and systematic postoperative nerve assessment are likely to identify an even higher incident of postoperative ulnar nerve dysfunction. Transposition was not protective in this analysis

Hip dislocations are uncommon injuries that result from high-energy mechanisms. These patients require careful trauma evaluation to rule out concomitant injuries. Early closed or open reduction that is performed within 6 hours and close radiological follow-up is recommended to obtain the best possible results. It is also essential to educate the patient regarding the potential sequelae and follow them for evidence of osteonecrosis and posttraumatic arthritis

BACKGROUND: There is much debate regarding the optimal treatment of displaced, unstable distal radial fractures in the elderly. The purpose of this retrospective review was to compare outcomes for elderly patients with a displaced distal radial fracture who were treated with or without surgical intervention. METHODS: This case-control study examined ninety patients over the age of sixty-five who were treated with or without surgery for a displaced distal radial fracture. All fractures were initially treated with closed reduction and splinting. Patients who failed an acceptable closed reduction were offered surgical intervention. Patients who did not undergo surgery were treated until healing with cast immobilization. Patients who underwent surgery were treated with either plate-and-screw fixation or external fixation. Baseline radiographs and functional scores were obtained prior to treatment. Follow-up was conducted at two, six, twelve, twenty-four, and fifty-two weeks. Clinical and radiographic follow-up was completed at each visit, while functional scores were obtained at the twelve, twenty-four, and fifty-two-week follow-up evaluations. Outcomes at fixed time points were compared between groups with standard statistical methods. RESULTS: Forty-six patients with a mean age of seventy-six years were treated nonoperatively, and forty-four patients with a mean age of seventy-three years were treated operatively. Other than age, there was no difference with respect to baseline demographics between the cohorts. At twenty-four weeks, patients who underwent surgery had better wrist extension (p = 0.04) than those who had not had surgery. At one year, this difference was not seen. No difference in functional status based on the Disabilities of the Arm, Shoulder and Hand scores and pain scores at any of the follow-up points was seen between the groups. Grip strength at one year was significantly better in the operative group. Radiographic outcome was superior for the patients in the operative group at each follow-up interval. There was no difference between the groups with regard to complications. CONCLUSIONS: Our findings suggest that minor limitations in the range of wrist motion and diminished grip strength, as seen with nonoperative care, do not seem to limit functional recovery at one year. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence

OBJECTIVES:: A delayed union or a nonunion of a fracture is a potentially adverse complication. Understanding the mechanisms of nonunion development may lead to improved treatment modalities. Proteases such as the matrix metalloproteinases play important roles in bone remodeling and repair, in which an imbalance or a nonfunctioning enzyme may lead to defects in bone healing (nonunion). The purpose of this pilot study was twofold: first to define an mRNA expression profile of all the matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases with thrombospondin motif (ADAMTS) enzymes, and their inhibitors (TIMPs) within fracture nonunion tissue, and second to compare this profile with mineralized fracture callus. METHODS:: Using a systematic real-time polymerase chain reaction, we screened the gene expression profiles of all members of the MMPs, ADAMTS, and their inhibitor TIMPs on human fracture nonunion tissue and matched mineralized callus tissue. Significant results were further analyzed using Western immunoblotting, immunohistochemistry, and in vitro protein interaction assays with bone morphogenetic protein-2. RESULTS:: This analysis confirmed MMP-7 and MMP-12 as two unidentified enzymes expressed in fracture nonunion tissue. Both MMP-7 and MMP-12 mRNAs were significantly elevated in nonunion tissue when compared with local mineralized callus from the same site (P < 0.001); the elevated protein levels of interest were visualized through immunoblotting and immunohistochemistry. In addition, these two MMPs were found to directly bind to and degrade bone morphogenetic protein-2 in vitro. CONCLUSION:: Collectively, our findings indicate that tissue present at the site of hypertrophic nonunions commonly expresses significantly higher levels of MMP-7 and MMP-12 in relation to mineralized fracture callus. Both were found to directly inactivate bone morphogenetic protein-2 in vitro, the best established growth factor in bone formation and repair

OBJECTIVE:: Bone morphogenetic proteins (BMPs) play important roles in the stimulation of osteogenesis and osteoinduction during bone fracture healing and their expression levels may be important for bone graft efficacy. The objective of this study was to determine if there are variations in the expression of BMPs and their receptors in various bone graft harvesting sites. We analyzed autogenous marrow aspirates obtained from three different graft sites for the mRNA levels of BMPs and their receptors. METHODS:: Using real-time polymerase chain reaction, we analyzed the mRNA levels of BMPs and their receptors in autogenous bone marrow aspirates obtained from three different bone graft sites of 10 different human subjects. Collection of autogenous bone marrow from the iliac crest, the proximal humerus, and the proximal tibia was performed using standard sterile techniques in the operating room as part of surgery to treat an established fracture nonunion. RESULTS:: The mRNA levels of BMP-2 and BMP-5 were the highest in the bone marrow aspirates from the three different sites, whereas the mRNA levels of the other osteoinductive BMPs (BMP-4, -5, -6, -7, -8, and -9) were lower. The mRNA levels of BMP-3, an inhibitor of osteogenesis, were the lowest in the bone marrow aspirates of all three different sites. There were no statistical significant differences in the mRNA levels of any of the BMPs or their receptors investigated in this study in the bone marrow of the three different sites. CONCLUSION:: Because no statistical significant differences in the mRNA levels of the BMPs and their receptors were detected in the bone marrow aspirates from the three different sites, our findings suggest that potential differences of various graft sites in the augmentation of bone healing does not result from different expression levels of BMPs

BACKGROUND:: The purpose of this article was to compare clinical and functional outcomes of surgically treated trimalleolar fractures with bimalleolar and unimalleolar ankle fractures. METHODS:: A prospective database was established to enroll all unstable ankle fractures treated operatively at our institution from October 2000 to July 2005. Demographic data on 456 patients, who sustained an unstable fracture of the ankle and were treated surgically, were entered into a database, and the patients were prospectively followed up. Of these 309 patients who had at least 1-year follow-up, 54 patients sustained an ankle fracture with involvement of the posterior malleolus. Two hundred fifty-five patients had an ankle fracture without involvement of the posterior malleolus. Of the 54 posterior malleolus fracture, 20 underwent fixation of the posterior malleolus. All patients were followed up at 3 months, 6 months, and 12 months after surgery and assessed functionally with Short Musculoskeletal Function Assessment and American Orthopaedic Foot and Ankle Society Scores. RESULTS:: There was no difference in age, sex distribution, or American society of anesthesiologists classification or incidence of diabetes between the two groups. At 1-year follow-up, all patients improved their function and pain status. Using the American Orthopaedic Foot and Ankle Society, patients with posterior malleolus fracture were significantly worse both for total score (p = 0.004) and pain function (p = 0.002). At 2-year follow-up, there was no significant difference in a smaller group of patients (41 patients). Using the Short Form-36, there was a significant difference seen with vitality and social function subgroups at 1 year. Using the Short Musculoskeletal Function Assessment, there was a significant difference at 1 year for dysfunction index (p = 0.04) for the trimalleolar group. CONCLUSION:: Most patients after unstable ankle fractures treated surgically do well; however, some patients continue to have some pain and dysfunction at 1 year. There was a significant difference in outcomes comparing patients with unstable ankle fractures associated with and without posterior malleolus fractures. The presence of a posterior malleolus fracture may indicate higher energy of injury, and it does seem to result in worse outcomes at 1 year, but this seems to even out over time as was seen at 2-year follow-up in a smaller group of patients