Philip R. Wolinsky

Impact of Smoking on Fracture Healing and Risk of Complications in Limb-threatening Open Tibia Fractures

Objectives: Current data show smoking is associated with a number of complications of the fracture healing process. A concern, however, is the potential confounding effect of covariates associated with smoking. The present study is the first to prospectively examine time to union, as well as major complications of the fracture healing process, while adjusting for potential confounders. Setting: Eight Level I trauma centers. Patients: Patients with unilateral open tibia fractures were divided into 3 baseline smoking categories: never smoked (n = 81), previous smoker (n = 82), and current smoker (n = 105). Outcome Measure: Time to fracture healing, diagnosis of infection, and osteomyelitis. Methods: Survival and logistic analyses were used to study differences in time to fracture healing and the likelihood of developing complications, respectively. Multivariate models were used to adjust for injury severity, treatment variations, and patient characteristics Results: After adjusting for covariates, current and previous smokers were 37% (P = 0.01) and 32% (P = 0.04) less likely to achieve union than nonsmokers, respectively. Current smokers were more than twice as likely to develop an infection (P = 0.05) and 3.7 times as likely to develop osteomyelitis (P = 0.01). Previous smokers were 2.8 times as likely to develop osteomyelitis (P = 0.07), but were at no greater risk for other types of infection. Conclusion: Smoking places the patient at risk for increased time to union and complications. Previous smoking history also appears to increase the risk of osteomyelitis and increased time to union. The results highlight the need for orthopaedic surgeons to encourage their patients to enter a smoking cessation programs.

Failure of less invasive stabilization system plates in the distal femur: A report of four cases

Four cases of failure of distal femoral Less Invasive Stabilization System plates are reported. Two modes of failure were observed: in 2 cases, the Less Invasive Stabilization System plates broke, and in 2 cases, the plates gradually displaced from the femur as the shaft screws lost purchase in the diaphyseal femoral cortex. Delayed union/nonunion, early weight bearing, and improper plate placement were identified as the etiologies for plate failure.

Length of Operative Procedures: Reamed Femoral Intramedullary Nailing Performed with and Without a Fracture Table

OBJECTIVES To determine whether performing reamed intramedullary nailing of the femur without the use of a fracture table decreases the length of operation. DESIGN Retrospective. SETTING Level 1 trauma center, Nashville. Tennessee. PATIENTS/PARTICIPANTS Consecutively treated patients with fractures of the femoral shaft were treated with intramedullary nails from June 1986 to March 1996. INTERVENTION Reamed intramedullary nailing of the femoral shaft was performed with the use of a fracture table or with the leg draped free on a radiolucent table. MAIN OUTCOME MEASUREMENTS Length of anesthesia time, prep and drape time (from the point the anesthetized patient is turned over to the surgeons until incision), and intramedullary nailing time (from incision until end of surgery) for reamed intramedullary nailing of the femoral shaft performed with and without the use of a fracture table were compared. RESULTS Univariate analysis showed statistically significant decreases in the length of prep and drape time, operative time, and anesthetic time when fractures were treated without the use of a fracture table. Multivariate analysis showed that use of a fracture table prolongs prep and drape time (plus twenty minutes), operative time (plus seventeen minutes), and anesthesia time (plus seventy-three minutes) when the covariates of age, sex, fracture location, learning curve, position of the patient, nail brand, and number of distal bolts are controlled. CONCLUSIONS Reamed intramedullary nailing of the femoral shaft performed without the use of a fracture table is significantly faster than when the procedure is performed with a fracture table.

The Effect of Plate Rotation on the Stiffness of Femoral LISS: A Mechanical Study

Objective: Malposition of the femoral Less Invasive Stabilization System (LISS) plate may alter its biomechanical behavior. This study compares the mechanical stability of “correctly” affixed LISS plates matching the slope of the lateral femoral condyle to “incorrectly” placed LISS plates fixed in external rotation relative to the distal femur. Methods: A fracture gap model was created to simulate a comminuted supracondylar femur fracture (AO/OTA33-A3). Fixation was achieved using two different plate positions: the LISS plate was either placed “correctly” by internally rotating the plate to match the slope of the lateral femoral condyle, or “incorrectly” by externally rotating the plate relative to the distal femur. Following fixation, the constructs were loaded in axial, torsional, and cyclical axial modes in a material testing machine. Main Outcome Measurement: Stiffness in axial and torsional loading; total deformation and irreversible (plastic) deformation in cyclical axial loading. Results: The mean axial stiffness for the correctly placed LISS constructs was 21.5% greater than the externally rotated LISS constructs (62.7 N/mm vs. 49.3 N/mm; P = 0.0007). No significant difference was found in torsional stiffness between the two groups. Cyclical axial loading caused significantly less (P < 0.0001) plastic deformation in the correct group (0.6 mm) compared with externally rotated group (1.3 mm). All the constructs in the incorrect group failed, where failure was defined as a complete closure of the medial fracture gap, prior to completion of the test cycles. Conclusion: Correct positioning of the LISS plate for fixation of distal femur fractures results in improved mechanical stability as reflected by an increased stiffness in axial loading and decreased plastic deformation at the bone-screw interface.

Can external fixation maintain reduction after distal radius fractures

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.

Effect of immediate weightbearing on plated fractures of the humeral shaft

BACKGROUND This study evaluated the effect of immediate weightbearing on fractures of the humeral shaft treated with dynamic compression plates. METHODS Eighty-three fractures met the inclusion criteria. The weightbearing status of the humerus was based on associated injuries and not the fracture pattern. There were no differences between the weightbearing and nonweightbearing groups in patient or fracture demographics. RESULTS Ninety-four percent of the fractures healed after the initial operation. Two in the nonweightbearing group and three in the weightbearing group required a second operation to achieve union. Alignment did not differ between the two groups. Immediate full weight. bearing had no effect on the union or malunion rate. CONCLUSION When indicated, open reduction and internal fixation of the diaphysis of the humerus, followed by immediate weightbearing through the involved humerus, is a safe and efficacious procedure.

Functional outcome of bilateral limb threatening: Lower extremity injuries at two years postinjury

Objectives: To describe the functional outcome of bilateral limb-threatening injuries at 2 years postinjury and to evaluate whether a different decision-making process should be used for these patients as opposed to patients with unilateral limb-threatening injury. Design/Setting/Patients: This study population of 32 patients is a subset of 601 patients from a study of 8 level I trauma centers. The patients were prospectively followed through 24 months. Main Outcome Measurements: The principle outcome measure at 2 years was the Sickness Impact Profile, designed to measure physical and psychosocial dimensions. Results: The overall Sickness Impact Profile scores at 2 years demonstrate that all 3 bilateral injury groups (bilateral salvage [n = 14], unilateral salvage/amputation [n = 8], and bilateral amputation [n = 10]) were severely disabled (Sickness Impact Profile >10). The bilateral salvage group had the most dramatic improvement over the 24 months. The 2-year physical subscale Sickness Impact Profile data showed a similar trend. At the 2-year assessment, the bilateral amputation group was recording greater disability (Sickness Impact Profile = 16.3) compared to the bilateral salvage and unilateral amputation/salvage groups (Sickness Impact Profile = 8.5 and 12.6, respectively). The overall Psychosocial Dimension, which started off worst in the bilateral salvage group, ended up similar in all 3 groups (8 to 9). The percent of patients who returned to work was 66.7% in the unilateral salvage/amputation group versus 21.4 and 16% in the bilateral salvage and amputation groups, respectively. Conclusions: The results indicate that treatment judgments should be based upon the results derived from the analysis of the larger unilateral limb cohort data. Patients with severe, bilateral lower extremity injuries should be counseled that regardless of treatment combinations, the function of each limb is similar at 24 months. The unilateral amputation/salvage group had a greater probability of going back to work. This is the major identifiable benefit to undergoing salvage versus amputation.

The distal approach for anterolateral plate fixation of the tibia: An anatomic study

Objectives: To determine what anatomic structures are at risk when placing plates from distal to proximal along the anterolateral border of the tibia. Design: Cadaveric dissection study. Setting: The Zimmer Institute, Warsaw, Indiana. Methods: A laboratory investigation was performed using 10 matched limbs (5 right and 5 left) of 5 fresh, frozen, nonpreserved cadaveric specimens. Dissections were carried out to identify the relationships between the plate/screw contructs and (1) the superficial peroneal nerve (SPN) and the pedicle containing the deep peroneal nerve and the anterior tibial vessels (DPN/ATV). Results: The SPN was always visualized in the subcutaneous tissues of the distal incision. The DPN/ATV courses along the posterior half of the tibial shaft proximally and crosses the distal third of the plate as it transitions to an anterior position The pedicle crosses and covers the tibia in a consistent region 40 to 110 mm proximal to the ankle joint. Conclusions: The distal anterolateral approach can be used to place plates along the anterolateral border of the tibia. The SPN is always seen in the distal incision and is not at risk. The structures at risk are the deep peroneal nerve and the anterior tibial vessels as they course from a posterior position proximally to a more anterior position distally.

The effect of C-arm malrotation on iliosacral screw placement.

Objectives: We sought to determine whether inaccurate C-arm positioning could create images that lead to inaccurate interpretation of iliosacral screw positions. Design: Cadaveric dissection study. Setting: The learning institute of Zimmer Inc. in Warsaw, Indiana. Methods: A laboratory investigation was performed using 3 nonpreserved cadaveric specimens. Several anatomic landmarks of the pelvis were outlined using radiographic markers and guide wires placed in several positions within the pelvis in each specimen. Using C-arm images we inserted the following: a “good” wire (GW), an out-the-front (OTF) wire, an out-the-back (OTB) wire placed into the sacral canal, an “in-out-in” (IOI) wire, and a wire in the S1 foramen (S1). The C-arm was then canted in 2-degree increments toward the head and then toward the feet starting from the optimum position. Results: Properly positioned wires always appear to be contained within bone regardless of the amount of malrotation of the C-arm from the optimum inlet and outlet views. Conclusions: Improper malrotated fluoroscopic inlet and outlet views of the pelvis will distort the anatomic landmarks of the pelvis before improperly placed guide wires appear to be correctly placed. Properly placed guide wires will always appear correctly positioned regardless of the malrotation of the C-arm. “Malrotated” views, however, can be used to rule out certain incorrect screw positions.

The use of hinged external fixation to provide additional stabilization for fractures of the distal humerus

Objective: To assess improvements in fixation stability when a hinged unilateral external fixator is used to supplement compromised internal fixation for distal humerus fractures. Methods: Removing a 1-cm section of the distal humerus in cadaveric whole-arm specimens created a comminuted distal humerus fracture model (AO type 13-A3). Fixation was then performed using different constructs representing optimal, compromised, or supplemented internal fixation. Internal fixation consisted of either 2 reconstruction plates with 1, 2, or 3 (optimal) distal attachment screws, or crossing medial and lateral cortical screws. A hinged external fixator was applied in combination with compromised internal fixation. The stability of the different constructs was then evaluated using 3-point bending stiffness and distal fragment displacement measurements during flexion and extension testing. Results: Addition of the external fixator increased the stiffness of all constructs. Stiffness of the compromised reconstruction plate constructs with supplemented fixation was similar to or significantly greater than that of optimal internal fixation. Addition of the fixator to the reconstruction plates with 1 screw or the crossing screws produced displacements of the distal fragment that were similar to those of the compromised constructs alone. However, medial/lateral and anterior/posterior displacements of the distal fragment during flexion and extension of the elbow for supplemented fixation were found to be greater than those for optimal internal fixation. Conclusions: The use of a hinged external fixator for supplemental fixation of distal humerus fractures may be effective in cases where internal fixation is severely compromised, although displacements may increase above optimal fixation.