Faculty Bibliography

A prospective study was conducted to determine the efficacy of using recombinant BMP-7 (rhOP-1) as an adjuvant in the treatment of diaphyseal humeral nonunions. Twenty-three consecutive patients with atrophic humeral diaphyseal nonunions were treated at seven separate institutions. All nonunions were fixed with either a compression plate or an intramedullary nail in conjunction with various bone grafting techniques. Recombinant OP-1 was delivered to the fracture site in a Type I collagen carrier at the time of fixation. All fractures went on to eventual union. There were no serious complications and no adverse reactions to the rhOP-I implant. Our study suggests that rhOP-1 may be a safe and effective adjuvant for the treatment of humeral diaphyseal nonunions

The purpose of this study was to determine the effect of the last hemoglobin level before patient discharge on outcome after hip fracture. We retrospectively reviewed data prospectively collected from July 1987 to December 1997 on 844 community-dwelling patients 65 or older who had sustained an operatively treated femoral neck or intertrochanteric fracture. Women with postoperative hemoglobin levels below 12.0 g/dL and men with levels below 13.0 g/dL were classified as having anemia. The main outcome measures were mortality, return to ambulatory ability, and return to activities of daily living at 3, 6, and 12 months. Hemoglobin data were available for 714 patients (85%). At time of last hemoglobin level measurement before discharge, 643 (90.1%) of the 714 patients were classified as having anemia. Patients who had sustained a femoral neck fracture that was treated with internal fixation were less likely to have anemia than were patients who had sustained a femoral neck fracture that was treated with hemiarthroplasty and patients who had sustained an intertrochanteric fracture (P < .001). Patients with anemia at the last discharge were not at increased risk for adverse outcomes at 3, 6, or 12 months compared with patients who did not have anemia

BACKGROUND: The purpose of this study was to confirm the prevalence of medial ankle widening among patients with an isolated fibular fracture and to determine the functional outcome of nonoperative treatment despite a diagnosis of a supination-external rotation stage-IV injury based on stress radiography. METHODS: One hundred and one patients with evidence of an isolated fibular fracture and an intact mortise seen on a standard ankle trauma radiograph series were evaluated with stress radiographs. Clinical signs were recorded at the time of presentation. A positive stress test was defined as > or =4 mm of widening of the medial clear space. Patients with a negative stress test were treated nonoperatively, those with a positive stress test and clinical signs of medial injury were treated surgically, and those with a positive stress test and no signs of medial injury were treated according to the preference of the surgeon and patient. The patients were followed prospectively with radiographs and ankle outcome scores. RESULTS: Sixty-six (65%) of the 101 patients had a positive stress radiograph. Thirty-six of them had signs of medial injury, and thirty had no medial injury. With regard to predicting a positive stress radiograph, medial tenderness had a sensitivity of 56% and a specificity of 80%, swelling had a sensitivity of 55% and a specificity of 71%, and ecchymosis had a sensitivity of 26% and a specificity of 91%. Of the subset of patients without signs of medial injury, twenty were treated nonoperatively (group I) and ten were treated operatively (group II). Two of the twenty patients in group I had evidence of persistent widening of the medial clear space at the time of the latest follow-up (mean, 7.4 months); only one of those patients was symptomatic. The average American Orthopaedic Foot and Ankle Society (AOFAS) score was 94 points in group I and 93 points in group II. CONCLUSIONS: We found a high rate of positive stress radiographs for patients who presented with an isolated fibular fracture and an intact ankle mortise on the initial radiographs. Medial tenderness, swelling, and ecchymosis were not sensitive with regard to predicting widening of the medial clear space on stress radiographs. All of the patients with a positive stress radiograph and no clinical symptoms who were treated without surgery had a good or excellent clinical result

BACKGROUND: The purpose of this study was to assess the effectiveness of external fixation and percutaneous pinning in maintaining distal radius fracture reduction over a 6-month period and to identify factors that might predict loss of fracture reduction. METHODS: Seventy cases had complete radiographic evaluation before surgery; at surgery; and at 6-week, 3-month, and 6-month follow-up. Radiographic parameters measured included volar tilt, dorsal displacement, radial inclination, radial height, radial shift, and ulnar variance. RESULTS: Dorsal tilt averaged 17.5 degrees from neutral before surgery; this value was corrected to 0.9 degree at surgery, but then progressed to 4.2 degrees by the 6-month follow-up. At 6-month follow-up, 49% of cases had lost more than 5 degrees of initially reduced volar tilt. However, none of these patients went from an acceptable initial reduction to an unacceptable reduction at 6 months. Initial deformity, patient age, use of bone graft, and duration of external fixation were not predictors of loss of reduction. CONCLUSION: Loss of reduction of volar tilt was seen for a period of up to 6 months after fixation, despite the use of pinning to hold the reduction. No specific predictor of loss of reduction was noted, although there was a trend toward loss of reduction in younger patients

OBJECTIVE: To review the biomechanical principles that guide fracture fixation with plates and screws; specifically to compare and contrast the function and roles of conventional unlocked plates to locked plates in fracture fixation. We review basic plate and screw function, discuss the design rationale for the new implants, and examine the biomechanical evidence that supports the use of such implants. DATA SOURCES: Systematic review of the per reviewed English language orthopaedic literature listed on PubMed (National Library of Medicine online service). STUDY SELECTION: Papers selected for this review were drawn from peer review orthopaedic journals. All selected papers specifically discussed plate and screw biomechanics with regard to fracture fixation. PubMed search terms were: plates and screws, biomechanics, locked plates, PC-Fix, LISS, LCP, MIPO, and fracture fixation. DATA SYNTHESIS: The following topics are discussed: plate and screw function-neutralization plates and buttress plates, bridge plates; fracture stability-specifically how this effects gap strain and fracture union, conventional plate biomechanics, and locking plate biomechanics. CONCLUSIONS: Locked plates and conventional plates rely on completely different mechanical principles to provide fracture fixation and in so doing they provide different biological environments for healing. Locked plates may increasingly be indicated for indirect fracture reduction, diaphyseal/metaphyseal fractures in osteoporotic bone, bridging severely comminuted fractures, and the plating of fractures where anatomical constraints prevent plating on the tension side of the bone. Conventional plates may continue to be the fixation method of choice for periarticular fractures which demand perfect anatomical reduction and to certain types of nonunions which require increased stability for union

A tape blister, a skin excoriation that occurs under the taped portion of surgical bandages, can be a source of postoperative morbidity. Tape blisters are caused by the separation of the epidermis from the dermis at the dermal-epidermal junction. Tape resistant to stretching contributes to blister formation because of the concentration of forces at the ends of the tape. Although tape blisters are a pervasive clinical problem, their incidence after hip surgery has rarely been reported in the orthopedic literature. Therefore, we retrospectively reviewed a consecutive series of patients with hip fractures to determine the incidence of tape blisters at our institution. One hundred three patients were included in the study. Tape-related injuries occurred in 22 patients (21.4%). Patient age, patient sex, number of medical comorbidities, smoking history, nutritional status, and type of surgery were not statistically significantly associated with risk for developing tape blisters

Hip fractures are common injuries in the elderly and are associated with considerable morbidity and mortality. Although technical advances in the treatment of the elderly have resulted in improved fracture fixation and surgical outcomes, clinical pathways have been developed to further improve patient outcome while shortening hospital length of stay after hip fracture. We describe the clinical pathway used since 1990 at the Hospital for Joint Diseases. The outcomes of 747 patients treated before 1990 were compared with outcomes of 318 patients treated at our hospital after initiation of the clinical pathway. Use of the clinical pathway was associated with significant decreases in the acute care hospital length of stay, in-hospital mortality, and 1-year mortality

BACKGROUND:: Bicondylar tibial plateau fractures are complex injuries, historically associated with high complication rates. The purpose of this study was: 1) to evaluate the clinical use L.I.S.S plating system for stabilization of bicondylar tibial plateau fractures. 2) To compare the biomechanics of this plating system with a double plate construct. METHODS AND MATERIALS:: Thirty-eight patients who sustained a complex tibial plateau fracture (OTA type 41C) at one of three level-one trauma centers were stabilized using the Less Invasive Stabilization System (L.I.S.S.). The cohort of patients was evaluated clinically and radiographically for outcomes at a mean 15 months.In phase 2 of this study a model of a bicondylar tibial plateau fractures was made in six matched pairs of embalmed, human tibia and randomized to fixation with either a L.I.S.S plate or a standard double plate construct. The tibias were then subjected to an axial cyclic load of 500N for 10 cycles (3Hz) to approximate 2 months in vivo and displacements measured. RESULTS:: Thirty-six of /38 (95%) patients united at 4 months after surgery with no loss of fixation nor infection. Two patients underwent prophylactic autogenous bone grafting for bone loss and united by 3 months postgrafting. Significant loss of knee range of motion (<90) was seen in five patients.Biomechanically, no differences in permanent inferior displacement of the medial fragment were found in initial axial loading and after 10 cycles between the two plate constructs. However, when loaded to 500N the L.I.S.S plate construct demonstrated almost twice the displacement of the medial fragment compared with the dual plate construct. No specimen lost fixation during cycling. CONCLUSION:: The L.I.S.S plating system provides stable fixation of complex bicondylar tibial plateau fractures allowing early range of knee motion with favorable clinical results

OBJECTIVES: The anterior curvature of the femur affects intramedullary nail insertion, revision prosthesis design, and the biomechanics of the proximal femur. Two previous studies, using small numbers of femurs, determined femoral curvature and showed that it was significantly greater than that of the several intramedullary nails they evaluated. In this study, the curvature of 948 femurs (474 matched pairs) was determined and compared with current intramedullary nails. The correlation of femoral curvature to age, gender, femoral size, and race was also evaluated. SETTING: Museum skeletal collections and a hospital biomechanics laboratory. METHODS: The curvature of 892 femurs (446) from the skeletal collections of 2 museums was measured by processing the digital images of the femurs with a computer curve-fitting program. Fifty-six additional, embalmed femurs (28 pairs) from our collection were also digitally imaged and then radiographed and their medullary curvatures similarly determined for comparison. Curvatures of 8 current antegrade intramedullary nails and 3 long-stemmed femoral hip prostheses were obtained from manufacturers and confirmed by measurements from their templates after digitization. RESULTS: We found the average femoral anterior radius of curvature was 120 cm (+/- 36 cm). There was no effect of age on femoral curvature nor was there a correlation between femoral width or femoral length to curvature. Black donor femurs had less curvature than white donor femurs (P < 0.001). There was close correlation (r = 0.967) between the femoral curvatures determined from the digital images and the radiographs. Radii of curvature of the intramedullary nails ranged from 186 to 300 cm (eg, straighter than the femurs). CONCLUSIONS: There was a large mismatch between the curvature of some current antegrade intramedullary nails and the average femur. Although this is only 1 factor affecting nail insertion, the mismatch warrants a reappraisal of these intramedullary nail designs. CLINICAL RELEVANCE: Because ease of intramedullary nail insertion and possibility of cortical comminution are determined by a number of factors including insertion point and fracture location, it appears that a decrease in radii of curvature (less straight) of current nail designs is warranted, particularly for those larger diameter nails designed for hip fracture stabilization that have greater rigidity due to design or material

BACKGROUND: The lateral trochanteric support plate (LSP) was developed to prevent excessive sliding of unstable intertrochanteric femur fractures fixed with a sliding hip screw (SHS). This study compared the fracture stability and screw sliding characteristics of unstable intertrochanteric femur fractures fixed with either an SHS and LSP or an Intramedullary Hip Screw (IMHS). METHODS: Six matched pairs of cadaveric human femurs with simulated, unstable intertrochanteric femur fractures were stabilized with either an IMHS or a 135-degree SHS with an attached LSP. Inferior and lateral head displacements and lag screw sliding distances were measured for applied static loads of 750 N, before and after cycling. RESULTS: Four-part unstable intertrochanteric femur fractures showed comparable screw sliding characteristics and stability whether instrumented with an SHS and LSP or an IMHS. CONCLUSION: A sliding hip screw with an attached lateral support plate provides stability and ability to resist medial displacement of the femoral shaft similar to that seen with the IMHS