Category: Trauma; Ankle;Other Introduction/Purpose: Malreduction in ankle syndesmosis repair is associated with post-operative pain, instability, and revision. Although multiple surgical techniques are designed to minimize malreduction, little is understood regarding the multi-factorial sources of error these techniques aim to address. For example, image interpretation errors may be particularly problematic, as previous work indicates identifying subtle fibular displacements from imaging is challenging for experienced orthopaedic trauma surgeons. In this context, this study evaluates whether surgical experience and/or inclusion of a visual aid improves surgeon accuracy during an image interpretation task. The task originates from the center-center technique, which is designed to minimize syndesmosis malreduction by drilling through the aligned centers of the tibia and fibula on an internally-rotated, lateral ankle x-ray. Methods: Twenty-eight individuals participated in this IRB-approved study (10 orthopaedic surgery attendings, 8 orthopaedic surgery residents, 10 medical students). Each evaluated 90 lateral ankle images arranged in two equal sets. In each set, the fibula was displaced from perfectly centered (-40% posterior to +40% anterior in 10% increments; each increment repeated 5 times). The two sets were identical, except one was augmented with a visual aid (or crosshair) marking the center of the tibia. Image and set order were randomized to control for learning effects. For each image, participants classified the fibula as 'centered' or 'non- centered' while wearing eye-tracking glasses. The glasses recorded two physiological measures of cognitive burden: blinks per image and image interpretation time. Statistical analyses tested the hypotheses that surgical experience and addition of a visual aid improved interpretation accuracy and decreased cognitive burden. Statistical significance (p <= 0.05) was evaluated using ANOVA followed by paired t-tests. Results: All participants accurately identified images with large fibular displacements (>20%) and perfectly centered (0%) images; however, interpretation accuracy at small displacements (10%) approximated random chance (Fig. 1A). Inclusion of a visual aid significantly improved image interpretation accuracy for both the full image set (p = 0.015, Fig. 1B) and images with small displacements (p = 0.025, Fig. 1A 10% and 20%). Although surgical experience was not a significant predictor of interpretation accuracy, surgical experience did significantly influence physiological measures of cognitive burden. Interestingly, inclusion of a visual aid slightly increased cognitive burden as measured by blinks per image for trainees, but significantly decreased this metric for attendings (p = 0.014, Fig. 1C). Compared to attendings, time per image was significantly increased for residents (p = 0.007), but not medical students (Fig. 1D). Conclusion: This study demonstrates that a visual aid can improve image interpretation accuracy for both experienced surgeons and trainees. Interestingly, the inclusion of the visual aid decreased the physiologically measured cognitive burden of attendings, but not trainees. This suggests that additional visual information displayed on an x-ray image may be processed and used differently by experienced versus inexperienced surgeons. Thus, this study provides foundational evidence that augmenting images can improve surgical accuracy and motivates future work to characterize how image augmentation influences clinical and educational outcomes.
Category: Trauma; Other Introduction/Purpose: Knee flexion has been demonstrated to impede popliteal venous return with large effect size among patients lying supine for surgery. Passive popliteal flow impedance has also been suggested to occur with knee scooter usage due to knee flexion. This study compared the effect of knee flexion angles on popliteal venous return between upright, crutch and knee scooter positioning when immobilized. Further, the countervailing effect of standardized hallux musculovenous pump activation was observed. Methods: This was an IRB approved study of young, healthy volunteers. Popliteal venous diameter and flow metrics were assessed with venous ultrasonography and compared between straight leg, crutch, and knee scooter positioning while wearing a walking boot and nonweightbearing. Flow was assessed with muscles at rest and with hallux musculovenous pump activation via active oscillation between hallux metatarsophalangeal joint extension and flexion at one motion per second (0.5 Hz) as paced by a metronome. Observer consistency was assessed. Paired-sample Student’s t-test and the Wilcoxon signed rank tests were used to assess within-subject differences for diameter and venous flow parameters, respectively. Knee flexion and musculovenous pump activation effects sizes were calculated. A priori sample size indicated 24 subjects were needed to achieve 80% power to detect a significant ( p < 0.006 ) difference in medial flow for any of 8 comparisons, assuming large effect sizes. Results: 16 of 24 (67%) subjects were female. Twelve limbs (50%) were right sided. The mean age was 21.9 years (SD 3.0 years) and the mean body mass index was 21.9 (SD 1.9). Observer consistencies were excellent (0.93 to 0.99). No significant differences in mean vessel diameter, time-averaged mean velocity, and total volume flow occurred. Corresponding knee flexion effect sizes were small (range -0.04 to -0.26). A significant decrease (-24%) in active median time-averaged peak velocity (TAPV) occurred between upright and crutch position (20.89 cm/s vs. 15.92 cm/s, p < 0.001) with a medium effect size (-0.51). Hallux musculovenous pump increased all flow parameters (all p< 0.001) and effect sizes were comparatively larger (>0.6) across all knee flexion positions. Conclusion: Compared to values reported for supine individuals, upright passive popliteal venous return was observed to be markedly diminished at all knee flexion angles. Knee flexion had minimal effect on diameter, a small effect in further diminishing TAMV and TVF and a medium effect on diminishing TAPV. Hallux musculovenous pump activiation had a large effect on increasing flow at all knee flexion angles. Patients may well be counseled to use toe motion to counter the negative effects of gravity, and to a lesser extent knee flexion, when using crutches and knee scooters while their ankle is immobilized.
Category: Ankle Introduction/Purpose: Distal tibiofibular syndesmosis sprain has been reported among 13% to 23% of all ankle fractures, often requiring surgery. However, post-operative malreduction rates have been reported to range from 0 to 54%. Optimal reduction is a significant predictor of overall functional outcome. The centroids of the tibia and fibula align the theoretically ideal axis of syndesmosis fixation alignment. The “Center-Center” method for syndesmosis fixation is a recently described intraoperative technique for aligning the central axes of the tibia and fibula on the ankle lateral fluoroscopic view, seemingly aligning the centroids. There is a lack of validation and outcomes data to support this technique. This study was performed in order to determine how reliably the ”center-center” technique aligns with the centroid axis of the fibula and tibia. Methods: This was a quantitative descriptive study utilizing 30 axial computed tomography scans from July 1, 2016 to June 30, 2018. Eighteen males and 12 females were included with an average age of 44-years-old. CT measurements were made using Visage 7. Three observers measured the maximum difference in degrees between the Center-Center and Centroid measurements at 10 mm, 20 mm, and 30 mm proximal to the tibial plafond for each patient. The Center-Center axis was established by internally rotating the CT image until the fibula aligned within the center of the tibia. The centroid measurement was established using a tool that calculated the centroid of each bone. Finally, the difference in external rotation required to obtain the Center-Center measurements were observed at levels 10 mm versus 20 mm, 20 mm versus 30 mm, and 10 mm versus 30 mm. Results: The Center-Center and Centroid axes were highly consistent within and between subjects and levels, differing on average by a mean 0.39 degrees (95% CI 0.29 to 0.49 degrees) across all comparisons. These axes externally rotated a mean 3.10 degrees (95% CI 2.56 to 3.64 degrees) from 10 mm to 20 mm and a mean 2.72 degrees (95% CI 2.35 to 3.09 degrees) from 20 mm to 30 mm. There were no statistically significant differences in the mean values obtained between observers for any axis at any height (p-value range 0.4 to 1.0) and intraclass correlation indicated excellent to near perfect interobserver agreement (ICC range, 0.876 to 0.988). Conclusion: The Center-Center technique consistently and closely aligns the fibula and tibia along the Centroid axis. These two axes externally rotate approximately 3 degrees for each 10 mm above the plafond. The Center-Center technique may offer the highly accurate means sought for achieving accurate and consistent intraoperative syndesmosis fixation alignment due to its highly consistent relationship to the Centroid axis. Surgeons should be aware of the external rotation of these axes between heights as the axes externally rotated a mean 3 degrees for each 10 mm height increase. Failure to correct limb rotation for each height could result in iatrogenic malreduction.
Category: Ankle Introduction/Purpose: Tibialis anterior tendon (TAT) rupture causes substantial morbidity. Nearly 200 surgical cases have been reported in the literature since 1905 wherein primary repair was not achieved approximately 40% of the time due to post- debridement tendon defect size. The present study describes the clinical outcomes of augmented, half-thickness TAT segment transposition, a novel reconstruction technique for managing post-debridement TAT defect. The purpose was to assess this technique as an alternative to tendon transfer and allograft tendon interposition. Methods: IRB-approved, retrospective electronic medical record review of patients with attritional distal TAT rupture. In all cases, the post-debridement tendon defect prohibited primary repair or reinsertion and was managed by distal transposition of a half-thickness TAT segment to span the defect. This graft was secured with a six core suture end-to-end anastomosis. Then, this repair was augmented with human acellular dermal matrix allograft (Graftjacket®, Wright Medical Technology, Memphis, TN). A total of five patients were treated with this technique. One patient died of unrelated causes remote from surgery and one was lost to follow up. Three patients with a minimum one year follow up were included. Outcomes were assessed via observed range of motion, clinical motor power assessment, ability to heel walk 15 feet, visual analog scale pain score, Foot and Ankle Ability Measure score, postoperative complications, and patient satisfaction at one year. Outcomes data were analyzed using descriptive statistics. Results: The mean age was 68 years (range, 59 to 73 years). Two patients were female. Mean interval between injury and surgery was 59.3 days (range, 15 to 146 days). All patients regained symmetrical range of motion, medical research council grade 5 motor power and the ability to heel walk. Mean pain scores improved from 4.6 (range, 2.5 to 8.5) preoperatively to 0.7 (range, 0 to 2) postoperatively. Mean FAAM scores increased from 30.6 (range, 23.8 to 43.8) preoperatively to 78.7 (range, 72.6 to 97.6) postoperatively. No postoperative complications occurred. At one year, one patient was satisfied and two were very satisfied with their outcome. Conclusion: Although constrained by a small sample size, the present findings appear to indicate that this technique produces short term clinical results comparable to those described for other techniques for TAT reconstruction. Future work should assess if these results are reproducible and long lasting. Additionally, the relative value of saving donor site morbidity or the cost of allograft tendon in comparison to the added cost of the Graftjacket should be determined
Category: Ankle Introduction/Purpose: The anterior incision is commonly used for total ankle replacement (TAR), and anterior approach ankle arthrodesis. Historically, the anterior incision has demonstrated a high incidence of complications, specifically with early generation TAR. Modern TAR designs have provided instrumentation and techniques that better respect the vulnerability of the anterior soft tissues, potentially reducing the incidence of anterior incision related complications. To our knowledge, anterior wound healing rates have not been evaluated in the context of modern anterior approach ankle arthrodesis and arthroplasty. The purpose of this study was to evaluate and compare the incisional healing and complications of the anterior approach for ankle arthrodesis and arthroplasty. Methods: This was an IRB-approved retrospective review of wound healing and complications among 304 patients who underwent primary TAR or ankle arthrodesis via the anterior approach between August 1, 2011 and August 31, 2015. Of the 304 patients, 191 (62.8%) underwent TAR and 113 (37.2%) underwent arthrodesis. The surgical approach, intraoperative soft tissue handling, and postoperative protocol for the first 30 days was the same between groups. Demographics, clinical characteristics of the wound healing, and neurovascular status were analyzed using two-sample t-tests or Wilcoxon rank sum tests for continuous variables and chi-square or Fisher’s exact tests for categorical variables. To diminish the effect of selection bias, a subgroup analysis was performed comparing 91 TAR patients matched to an equal number of ankle arthrodesis patients based upon gender, age, diabetes, and smoking status. Results: The mean follow-up was 11.8 (range, 1.4 to 62.2) months. Overall, 19.7% of patients experienced delayed wound healing greater than 30 days, 15.8% required office-based wound care, 12.2% had a wound infection, 15.1% were prescribed antibiotics, 9.5% underwent wound debridement in the office, 4.6% had nerve injury, and 0.7% had a vascular injury. Implant revision or removal occurred in 10.5%, with a bias towards hardware removal in ankle arthrodesis. In the entire group of 304 patients, there was no difference between TAR and arthrodesis in risk of incisional wound challenges or complications nor neurovascular injury. In the subgroup matched for gender, age, diabetes status and smoking history there was no difference in outcomes. Conclusion: In this large cohort of 304 patients undergoing anterior approach to the ankle, postoperative complication rates were constant at all levels of analysis, with no difference seen between anterior ankle arthrodesis or ankle approach total ankle arthroplasty. This suggests that the primary determinates of complications were neither the demographic nor implant factors considered herein. The anterior ankle incision has a documented wound complication risk, regardless of the surgical procedure, and any modifiable risk factors remain elusive.
Knee scooters are commonly used for mobility instead of other devices. However, passive popliteal venous flow impedance has been observed with knee scooter usage ostensibly as a result of deep knee flexion. This study aimed to characterize the magnitude of impact knee flexion has on popliteal venous flow in relation to the degree of knee flexion when walking boot immobilized. Furthermore, the countervailing effect of standardized pedal musculovenous pump (PMP) activation was observed. Popliteal venous diameter and flow metrics were assessed with venous ultrasonography in 24 healthy individuals. Straight leg, crutch, and knee scooter positioning while wearing a walking boot and non-weight-bearing were compared. Flow was assessed with muscles at rest and with PMP activation. Of 24 participants, 16 (67%) were female. Twelve limbs (50%) were right sided. The mean age was 21.9 (SD = 3.0) years, and the mean body mass index was 21.9 (SD 1.9) kg/m2. Observer consistencies were excellent (intraclass correlation range = 0.93 to 0.99). No significant differences in mean vessel diameter, time-averaged mean velocity, and total volume flow occurred (all P > .01). Corresponding knee flexion effect sizes were small (range = -0.04 to -0.26). A significant decrease (-24%) in active median time-averaged peak velocity occurred between upright and crutch positions (20.89 vs 15.92 cm/s; P < .001) with a medium effect size (-0.51). PMP activation increased all flow parameters (all P < .001), and effect sizes were comparatively larger (>0.6) across all knee flexion positions.Clinical Significance: Knee flexion has a small to medium impact on popliteal venous return in healthy patients. Active toe motion effectively counters the negative effects of gravity and knee flexion when the ankle is immobilized.Levels of Evidence: Therapeutic, Level IV.
Disorders of the Achilles tendon, the largest tendon in the human body, are common and occur in both active and sedentary persons. A thorough history and physical examination allow primary care physicians to make an accurate diagnosis and to initiate appropriate management. Mismanaged or neglected injuries markedly decrease a patient's quality of life. A growing body of related literature is the basis for current therapeutic regimens, which use a multimodal conservative approach, including osteopathic manipulative treatment. Although primary care physicians can manage most cases of Achilles tendon disorders, specialty care may be needed in certain instances. Procedural intervention should consider any comorbid conditions in addition to patients' lifestyle to help guide decision making. When appropriately managed, Achilles tendon disorders generally carry a favorable prognosis.
