Tibial torsion correlates with talar morphology.

BACKGROUND: There is limited literature on axial rotation of the ankle or variations in anatomy of the talus. We aim to evaluate the rotational profile of the distal tibia and its relationship to talus morphology, radiographic foot-type, and tibiotalar tilt in arthritic ankles. METHODS: Preoperative imaging was reviewed in 173 consecutive patients with ankle arthritis. CT measurements were used to calculate tibial torsion and the talar neck-body angle (TNBA). Tibiotalar tilt and foot-type were measured on weightbearing plain radiographs. RESULTS: Measurements indicated mean external tibial torsion of 29.2±9.1˚ and TNBA of 35.2±7.5˚ medial. Tibiotalar tilt ranged from 48˚ varus to 23.5˚ valgus. A moderate association between increasing external tibial torsion and decreasing TNBA was found (ρ=-0.576, p<.0001). Weak relationships were found between external tibial torsion and varus tibiotalar tilt (ρ=-0.239, p=.014) and plantarflexion of the talo-first metatarsal angle (ρ=-0.218, p<.025). CONCLUSION: We observed a statistically significant correlation between tibial torsion and morphology of the talus, tibiotalar tilt, and first ray plantarflexion. This previously unreported association may provide information regarding the development of foot and ankle deformity and pathology. LEVEL OF EVIDENCE: Level III.

Proximal Femoral Shortening and Varus Collapse After Fixation of "Stable" Pertrochanteric Femur Fractures.

OBJECTIVES: To evaluate and compare femoral neck shortening and varus collapse in stable pertrochanteric femur fractures treated with sliding hip screws (SHSs) or cephalomedullary nails (CMNs). DESIGN: Retrospective review. SETTING: Academic medical center. PATIENTS: A total of 290 patients were included in the study. The average age was 82 years, and most were women. All sustained low-energy pertrochanteric femur fractures (OTA/AO A1.1, 1.2, 1.3, 2.2) treated operatively with SHSs or CMNs. Minimum radiographic follow-up was 3 months, with an average of 28 (range 3-162) months. INTERVENTION: CMN or SHS fixation. MAIN OUTCOME MEASURES: Varus collapse of the femoral neck-shaft angle and proximal femoral shortening. RESULTS: Both implants allowed some varus collapse. Univariate analysis demonstrated a significantly greater portion of patients with SHSs progressed to varus collapse >5 degrees (P = 0.02), mild horizontal shortening >5 mm (P < 0.01), and severe horizontal shortening >10 mm (P < 0.01). There was no statistical difference in vertical shortening (P = 0.3). There was no difference in implant failure (P = 0.5), with failure rates of 3% for cephalomedullary implants and 5% for SHS constructs. CONCLUSIONS: The SHS group experienced greater varus collapse and horizontal shortening. There was no difference in overall implant failure. These findings suggest that the CMN is a superior construct for maintenance of reduction in stable pertrochanteric fractures, which may lead to improved functional outcomes as patients recover. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Impact of Knee Scooter Flexion Position on Venous Flow Rate.

BACKGROUND:: The knee scooter is a commonly used mobility device in the setting of unilateral below-knee immobilization. The bent-knee posture has been shown to decrease venous flow in a seated position, but the knee scooter differs as the patient is weightbearing through the affected extremity. Our goal was to investigate the effects of knee scooter positioning on popliteal venous flow. METHODS:: Duplex ultrasonography was performed to obtain venous diameter and flow velocity of the popliteal vein on healthy subjects over the age of 18 without immobilization. Measurements were performed on the left knee of each subject while standing and with the same knee flexed on the knee scooter, by 2 physicians trained in ultrasound techniques. Mean velocity, peak velocity, vessel diameter, and volumetric flow rate were calculated and t tests were performed for each variable. A power analysis was performed, determining that 9 subjects would provide 80% power with an alpha of 0.05. A total of 13 subjects participated in the study. Mean age was 33 (range 20-56) years, with 6 females and 7 males. RESULTS:: Measurements of subjects while standing and on the knee scooter demonstrated a significant decrease in mean velocity (6.5 vs 3.2 cm/s, P < .01) and volumetric flow rate (227.8 vs 106.2 mL/min, P < .01) while subjects were using the scooter. Vessel diameter (0.82 vs 0.78 cm, P = .15) and peak velocities (19.8 vs 14.7 cm/s, P = .19) were not significantly different between standing and kneeling positions. CONCLUSION:: Our findings demonstrated a statistically significant decrease in volumetric flow rate in subjects using a knee scooter device with a flexed knee. Although venous stasis is a known risk factor for DVT, flow rate thresholds for increased thrombus formation are not well defined. The duration of scooter use, or flexed knee positioning, may have some effect on the degree of stasis. This finding should caution orthopedists to consider the risk attributed to the knee scooter as part of their overall patient assessment. LEVEL OF EVIDENCE:: Level II, therapeutic, comparative study.

Risk factors for reoperation, readmission, and early complications after below knee amputation.

BACKGROUND: Many patients undergoing below knee amputations (BKA) return for subsequent unplanned operations, hospital readmission, or postoperative complications. This unplanned medical management negatively impacts both patient outcomes and our healthcare system. This study primarily investigates the risk factors for unplanned reoperation following BKA. METHODS: Below knee amputations from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database from the years 2012-2014 were identified by CPT code 27880 for amputation through the tibia and fibula. Our query identified 4631 BKA cases, including 30 day complications. Multivariate logistic regression modeling was performed on several patient demographic and disease factors to assess for independent predictors of unplanned reoperation. Secondary outcomes of unplanned and related readmissions (related to the procedure), major complications, minor complications, and mortality were also included in the analysis. RESULTS: Of 4631 BKAs identified, 9.63% (446/4631) underwent unplanned reoperations and 8.75% (405/4631) had unplanned and related readmissions. Major complications were experienced by 12.8% (593/4631) and minor complications by 8.7% (401/4631). Thirty day mortality rate was 5.14% (238/4631). The most common procedures for unplanned operations were thigh amputations (128/446, 28.7%), debridement/secondary closure (114/446, 25.6%), and revision leg amputations (46/446, 10.32%). Factors associated with an increased risk of unplanned reoperation included patients transferred from another facility (Adjusted Odds Ratio [AOR] = 1.28; p = .04), recent smokers (AOR = 1.34; p = .02), bleeding disorder (AOR = 1.30; p = .02), and preoperative ventilator use (AOR = 2.38; p = .01). CONCLUSION: Patients that were ongoing/recent smokers, had diagnosed bleeding disorders, required preoperative ventilator use, or were transferred in from another facility were associated with the highest risks of reoperation following BKA. This patient population experiences high rates of reoperation, readmission, complication, and mortality.

Risk Factors Associated With Cephalomedullary Nail Cutout in the Treatment of Trochanteric Hip Fractures.

OBJECTIVES: To evaluate the association of cephalomedullary nail cutout in trochanteric femur fractures with the presence of the following radiographic variables: lateral wall fracture, posteromedial fragment, angular malreduction, residual basicervical fracture gapping, screw placement, and tip-apex distance. DESIGN: Retrospective review. SETTING: Academic medical center. PATIENTS: A total of 362 patients were included in the study. The average age was 83 years and the majority was female. All sustained low-energy trochanteric femur fractures treated operatively with cephalomedullary nails. Minimum radiographic follow-up was 3 months, with an average of 11 (range 3-88) months. INTERVENTION: Cephalomedullary nailing with either a lag screw or helical blade. MAIN OUTCOME MEASURES: Cutout of the lag screw or helical blade. RESULTS: A total of 22 (6%) cutouts occurred. Univariate analysis showed significantly (P ≤ 0.01) more frequent cutout with fracture of the lateral wall, posteromedial fragment, residual gapping (>3 mm) at basicervical component, neck-shaft malreduction >5 degrees varus or 15 degrees valgus, and tip-apex distance >25 mm, and superior screw/blade positioning. There was no difference with unstable fracture pattern (P = 0.58) or fellowship training (P = 0.21). Multivariate regression analysis demonstrates that lateral wall fracture (Odds ratios [OR] = 8.0, 95% confidence interval [CI], 2.4-27.1), neck-shaft malreduction (OR = 4.3, CI, 1.3-14.7), and residual basicervical gapping (OR = 3.6, CI, 1.0-13.0) were associated with fixation cutout. CONCLUSIONS: Risk factors for cutout of trochanteric fractures in our study can be viewed as modifiable or nonmodifiable factors. Statistically significant factors included lateral wall fracture (nonmodifiable) as well as basicervical gapping and malreduction (modifiable). LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.