Image Rotation Alters Apparent Fibula Length: An Evaluation of Talocrural Angle, Shenton Line, and Dime Sign.

BACKGROUND: Fibula shortening can compromise ankle stability and force transmission, thereby impacting clinical outcomes. Because radiographs depict 3-dimensional anatomy in 2 dimensions, accurate radiographic assessment of fibula length is a commonly encountered clinical challenge. The talocrural angle (TCA), Shenton line, and dime sign are useful parameters of fibula length. Yet, the impact of 3-dimensional limb positioning on these radiographic parameters is not established. METHODS: Bone models were constructed from CT scans of 30 lower limbs. Fibula length was computationally manipulated, and digitally reconstructed radiographs were generated reflecting 1-degree increments of sagittal and axial plane rotation of each limb for each fibula length condition. The TCA was computationally measured on each image. The presence of an aligned mortise view, intact Shenton line, and intact dime sign was assessed by 2 observers. RESULTS: The mean TCA, which was 78.0 (95% CI ± 1.6) degrees for a true mortise projection with anatomic fibula length, changed by approximately 1 degree per millimeter of fibula length change. On average, 14.7 degrees of caudal rotation obscured 2 mm of fibular shortening by virtue of producing the same TCA as a true mortise view with anatomic fibula length, designated a false positive view. Axial rotation had a comparatively small effect. Observers 1 and 2 were, respectively, 91% and 88% less likely to accurately judge the image alignment of the false positive images compared to true mortise images. Moreover, intraobserver agreement was poor to moderate (mean 0.47, range 0.13-0.59) and interobserver agreement was uniformly poor (mean 0.08, range 0.01-0.20). CONCLUSION: In our study using digitally reconstructed radiographs from CT scans of 30 limbs, we found that sagittal plane rotation impacts the radiographic appearance of fibula length as measured by the TCA. Limb axial rotation had a comparatively small effect. Further study of human perception of Shenton line and dime sign is needed before the effect of rotation on these parameters can be fully understood. LEVEL OF EVIDENCE: Level IV, case series.

The Center-Center Image Closely Approximates Other Methods for Syndesmosis Reduction Clamp Placement.

BACKGROUND: The optimal placement for a syndesmosis reduction clamp remains an open question. This study compared the center-center axis, which localizes clamp placement using only an internally rotated lateral ankle X-ray, with other common approaches, whose accuracy can only be confirmed using computed tomography (CT). METHODS: Bone models of anatomically aligned (n = 6) and malreduced (n = 48) limbs were generated from CT scans of cadaveric specimens. Four axes for guiding clamp placement (center-center, centroid, B2, and trans-syndesmotic) were then analyzed, using digitally reconstructed radiographs derived from the bone models. Each axis' location was defined using angle-height pairs that describe axis orientation along the full anatomical region where syndesmosis fixation occurs. RESULTS: In anatomically aligned limbs, the center-center axis was located on average (±95% CI [confidence interval]), 0.64° (±0.50°) internal rotation, 1.03° (±0.73°) internal rotation, and 2.09° (±7.29°) external rotation from the centroid, B2, and trans-syndesmotic axes, respectively. Fibular displacement altered the magnitude of limb rotation needed to identify the center-center axis. CONCLUSION: The center-center technique is a valid method that closely approximates previously described methods for syndesmosis clamp placement without using CT, and the magnitude of C-arm rotation needed to transition from a talar dome lateral to a center-center view may be a potential method for assessing syndesmosis reduction. LEVELS OF EVIDENCE: Level III: Retrospective comparative study.

Biomechanical Sequelae of Syndesmosis Injury and Repair.

This review characterizes fibula mechanics in the context of syndesmosis injury and repair. Through detailed understanding of fibula kinematics (the study of motion) and kinetics (the study of forces that cause motion), the full complexity of fibula motion can be appreciated. Although the magnitudes of fibula rotation and translation are inherently small, even slight alterations of fibula position or movement can substantially impact force propagation through the ankle and hindfoot joints. Accordingly, implications for clinical care are discussed.

Pedal Musculovenous Pump Activation Effectively Counteracts Negative Impact of Knee Flexion on Human Popliteal Venous Flow.

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.

Comparable outcomes with intramedullary nail and plate constructs for Schatzker VI tibial plateau fractures.

BACKGROUND: Outcomes data of intramedullary nail fixation (IMN) constructs for complex Schatzker VI tibial plateau fractures are scant in the literature. This study compares the clinical and radiographic outcomes of IMN, dual plate, and single plate constructs for Schatzker IV tibial plateau fractures. METHODS: Retrospective cohort study of sixty-two patients at a University-based Level 1 trauma center who underwent open reduction internal fixation for Schatzker VI tibial plateau fracture. Constructs evaluated were IMN (with or without raft screws), dual plating, and single plating. Demographic, clinical, and radiographic outcomes were recorded. All fractures were additionally classified based on the OTA classification for sub analyses. Mean follow-up was 13.2 (SD 13.3) months. Predictors of construct selection and outcomes were evaluated with bivariate logistic regression. Outcomes were compared between groups with independent samples t-tests and Chi Square tests. RESULTS: No significant demographic differences were found between IMN, dual plate or single plate construct cohorts. There was a higher proportion of open fractures within the IMN construct group versus the dual plate cohort (21.1% vs 3.6%). No statistically significant differences in radiographic outcomes were observed between cohort groups except for small but statistically significant differences in condylar width (CW) ratio change and tibial slope; when fracture cohorts were sub analyzed by specific OTA classification, there were no significant differences in any radiographic outcomes. There was a significant difference between the ratio of OTA 41C1, C2 and C3 fractures regarding treatment allocation (p = 0.004), favoring dual plate fixation for OTA 41C3 fractures. There were no significant differences found between treatment cohorts in terms of all cause complications (p > 0.05). IMN and single plate constructs were utilized when posteromedial condyle fractures were nondisplaced or minimally displaced. CONCLUSION: Intramedullary nail fixation with or without supplemental raft screws produced similar short-term clinical and radiographic results compared to dual and single plate constructs among patients with Schatzker VI fracture types, regardless of OTA classification. Level of Evidence Level III retrospective cohort.

Intraoperative Assessment of Reduction of the Ankle Syndesmosis.

PURPOSE OF REVIEW: Postoperative malreduction of the ankle syndesmosis is common, poorly defined, and its assessment is controversial. In the absence of a gold standard method to evaluate the ankle syndesmosis, a variety of techniques have been described. As the knowledgebase expands, data illustrating caveats for such techniques has become available. The purpose of this review is to highlight literature-sourced technical pearls and their related caveats for the intraoperative assessment of the ankle syndesmosis. RECENT FINDINGS: Although numerical criteria are commonly used to assess syndesmotic reduction, anatomical variation in the healthy population frequently exceeds proposed cutoffs. Patient-specific uninjured anatomy can be defined by comparing to the uninjured contralateral ankle; however, side-to-side variation is present for many anatomical relationships. Advanced imaging (e.g., lateral radiographs, 3-dimensional radiography) can influence intraoperative surgeon decision-making and improve syndesmosis reduction, but minute improvements in syndesmosis reduction may not outweigh increased operating time and costs. Intraoperative imaging is an adjunct, not a replacement for direct visualization or palpation when reducing the syndesmosis. Arthroscopy may benefit younger patients with high physical demands by improving identification of intra-articular pathology absent on MRI. Although anatomical reduction is important to restore pre-injury biomechanics, it is unclear whether differences in reduction quality influence patient-reported outcomes. In the absence of a gold standard, awareness of the options for intraoperative assessment of the syndesmosis and their respective accuracy and limitations reported herein could enhance surgeons' ability to intraoperatively reduce the syndesmosis with the tools currently available.

Syndesmosis Injury Contributes a Large Negative Effect on Clinical Outcomes: A Systematic Review.

INTRODUCTION: The literature largely addresses questions of diagnostic accuracy and therapeutic accuracy. However, the magnitude of the clinical impact of syndesmosis injury is commonly described in intuitive yet qualitative terms. This systematic review aimed to quantify the impact of syndesmosis injury. METHODS: Published clinical outcomes data were used to compute an effect size reflecting the impact of syndesmosis injury. This was done within the clinical contexts of isolated syndesmosis injury and syndesmosis injury with concomitant ankle fracture. Clinical outcomes data included Olerud-Molander (OM) and American Orthopaedic Foot and Ankle Society (AOFAS) scores, visual analog scale for pain, and days missed from sport competition. Parametric data were compared with Student t tests. Effect size was computed using Cohen's d. RESULTS: In ankle fracture patients, syndesmosis injury demonstrated a large effect size for OM (d = 0.96) and AOFAS (d = 0.83) scores. In athletic populations without concomitant ankle fracture, syndesmosis injury demonstrated a large effect size on days missed from competition (d = 2.32). DISCUSSION: These findings confirm the magnitude of the negative impact of syndesmosis injury in athletic populations with isolated injury and in ankle fracture patients. In ankle fracture patients, this large negative effect remains despite surgery. Thus, syndesmosis repair may not fully mitigate the impact of the injury. LEVELS OF EVIDENCE: Level III: Systematic review.

Impact of Bone Graft on Fusion Rates in Primary Open Ankle Arthrodesis Fixated With Cannulated Screws: A Systematic Review.

There is currently no consensus on the importance of bone graft use in ankle arthrodesis. Despite this, bone graft is widely used. We aimed to summarize the available literature on primary open ankle arthrodesis fixated with cannulated screws in order to assess the importance of bone graft in achieving more favorable rates of fusion. PubMed and Embase were queried for articles reporting on primary open ankle arthrodesis fixated with cannulated screws which specified use or non-use of bone graft. Pooled data analysis was performed. Modified Coleman Methodology Scores were calculated to assess reporting quality. Twenty-seven studies met our inclusion criteria and were divided into three groups: no bone graft (NBG), fibular onlay with bone graft (FOBG), and use of bone graft (BG). All three groups had comparable fusion rates of 94.7%, 95.3%, and 95.1% respectively (p = .98). Number needed to treat was 7 and Absolute Risk Reduction was 14.8%. The reviewed literature was largely of moderate quality, with an overall Coleman score of 60.6 and no significance between the 3 groups (p = .93). In conclusion, primary open ankle arthrodesis fixated with cannulated screws generally had favorable fusion rates, and bone graft use did not have a significant effect on union rates. The available literature suggests that bone graft may not be needed in routine tibiotalar arthrodesis in low-risk patients. It may more significantly impact patients who are at high-risk of fusion failure, and dedicated research on this high-risk subset of patients is required.

Anterior Ankle Incision Wound Complications Between Total Ankle Replacement and Ankle Arthrodesis: A Matched Cohort Study.

The anterior incision is commonly used for total ankle replacement (TAR) and ankle arthrodesis. Historically, the anterior incision has demonstrated a high incidence of complications. The purpose of this study was to evaluate anterior incisional healing and soft tissue complications between TAR and ankle arthrodesis with anterior plate fixation.This was an IRB-approved retrospective review of wound healing and other complications among 304 patients who underwent primary TAR (191 patients) or ankle arthrodesis (113 patients) via the anterior approach over a 4-year period. The operative approach, intraoperative soft tissue handling, and postoperative protocol for the first 30 days were the same between groups. The mean follow-up was 11.8 months. To diminish the effect of selection bias, a subgroup analysis was performed comparing 91 TAR patients matched to an equal number of demographically similar ankle arthrodesis patients. Overall, 19.7% of patients experienced delayed wound healing greater than 30 days. Although the TAR and arthrodesis subgroups had dissimilar demographics, there was no difference in outcomes. Between matched pairs, no statistically significant differences were observed; however, trends were identified with matched cohort groups when compared to the overall patient series. These trends toward statistically significant differences in delayed wound healing and incidence of wound care in the matched cohort groups warrants further investigation in larger series or multicenter study. Further work is needed to identify the modifiable risk factors associated with the anterior ankle incision.

Reliability of the "Clinical Tibiofibular Line" Technique for Open Syndesmosis Reduction Assessment.

BACKGROUND: When intraoperative computed tomography (CT) is unavailable, open syndesmosis assessment is a universally available, safe alternative that is more accurate than radiographic assessment. However, it has a documented malreduction rate of up to 16%. This may be improved upon with a validated technique for assessing the accuracy of open syndesmosis reductions. The "tibiofibular line" (TFL) is a CT-based technique found to be sensitive for malreduction. The purpose of this study was to assess the feasibility of adapting the CT-TFL method into a reliable intraoperative open technique by refining the methodology of previous work exploring the clinical TFL technique. METHODS: Three observers were instructed to clinically simulate the TFL on cadaveric lower limbs. For each specimen, observers repeated and recorded 3 clinical TFL measurements for each of 4 measurement series representing different degrees of fibula reduction. Intraclass correlation was used to assess intra- and interobserver reliabilities. RESULTS: Mean intraobserver reliability was .88. Mean interobserver reliability was .75. Both intra- and interobserver reliabilities were highest for anatomic syndesmosis reduction. CONCLUSION: The findings of excellent to near perfect intraobserver and good to excellent interobserver reliability indicate the feasibility of translating the CT-TFL into a reliable open technique. LEVELS OF EVIDENCE: Level III: Diagnostic study.

Brake Response Time Recovery After Achilles Tendon Repair.

Background. This study evaluated when patients' brake response time (BRT) recovers after right Achilles repair. Methods. Institutional review board-approved prospective study of 60 patients. Assessments included visual analogue scale pain (VAS) score, Achilles Tendon Total Rupture Score (ATRS), and a driver readiness survey. Emergent brake pedal operation was simulated at 6 weeks postoperatively and repeated until patients achieved a passing BRT. Results. Fifty-seven patients completed the study. At 6 weeks, 54 of 59 (91.5%) patients had a passing BRT with a mean of 0.60 seconds (SD 0.08 seconds). Five (8.5%) patients had a failing BRT with a significantly higher mean of 0.95 seconds (SD 0.13 seconds, P = .01). At first testing, all patients were ambulating in a walking boot with removable heel wedges. Those who passed were using significantly fewer wedges (mean 1.9 vs 2.6 wedges, P = .04). Mean VAS pain scores (Passed: 1.1, SD 1.57, vs Failed: 2.8, SD 3.35, P = .32) were not significantly different. The mean ATRS was significantly lower among those who passed (63.7, SD 16.7, vs 85.4, SD 11.1, P = .01. Three patients repeated testing at a mean 7.3 weeks (range 6.7-8). All achieved passing times (mean 0.68 seconds, range 0.55 to 0.77 seconds). The driving readiness survey was 100% sensitive but 31.3% specific for passing BRT. Its positive predictive value was 80%, and its negative predictive value was 100%. Conclusion. BRT normalizes around 6 to 7 weeks after open right Achilles tendon repair. The ATRS and driver readiness questionnaire corresponded to achieving a passing BRT. Levels of Evidence: Prognostic Level II: Prospective Cohort Study.

Outcomes of the Extended Z-Cut Osteotomy for Correction of Adult Acquired Flatfoot Deformity.

BACKGROUND: Medial displacement calcaneus tuberosity osteotomy and anterior process lengthening calcaneus osteotomy are traditional single-plane osteotomy techniques used in adult acquired flatfoot deformity reconstruction. More recently, 3-plane step-cut osteotomies were described for each of these and shown to offer improved rotational stability via the horizontal limb. However, a major technical challenge is achieving a sufficiently long horizontal limb to correct deformity through lengthening without losing bony apposition. Combining the anterior process and tuberosity step-cuts using an elongated horizontal limb alleviates this technical challenge, creates a very large surface area for bony healing, and utilizes a single incision. We hypothesized that the Z-cut osteotomy would achieve clinical and radiographic flatfoot deformity correction with a high union rate. METHODS: This was an institutional review board-approved retrospective study of 16 patients who underwent Z-cut osteotomy for the treatment of moderate to severe symptomatic adult acquired flatfoot deformity, stage IIA/B. The mean radiographic follow-up was 8.8 months, while the mean clinical follow-up was 2.36 years. Radiographic correction was assessed via weightbearing radiographs taken preoperatively and at a mean of 26 ± 2 weeks postoperatively. Measurements included Meary's angle (talo-first metatarsal angle), talonavicular (TN) joint uncoverage percentage, TN incongruency angle, medial cuneiform to fifth metatarsal height, and calcaneal pitch. Union rates and clinical outcomes via the Foot Function Index (FFI) score were assessed preoperatively and at a mean of 29 months following surgery. Paired t test was used to compare both clinical and radiographic outcomes with statistical significance set at P < .05. RESULTS: Fifteen of 16 patients returned an FFI questionnaire with a mean improvement of 52.1 to 10.3 (P = .002). The calcaneal pitch improved from 12.7 to 15.2 degrees (P = .002), the medial cuneiform-fifth metatarsal distance improved from 12.8 to 18.5 mm (P = .002), the TN coverage angle improved from 21.3 to 9.1 degrees (P < .001), the TN uncoverage percentage improved from 32.9% to 20.3% (P < .001), and the TN incongruency angle improved from 41.4 to 19.9 degrees (P < .001). Deformity correction was well maintained in 13 of 16 patients at final follow-up. The union rate of the osteotomy was 100%. Three patients had symptomatic hardware initially; 1 patient required removal of hardware. One patient developed a superficial infection that cleared. Another patient developed peroneal tendonitis, which resolved with corticosteroid injection. CONCLUSION: The Z-cut osteotomy is a novel, technically simplified, single-incision, single-osteotomy alternative to the previously described double calcaneus osteotomy techniques for reconstructing flexible moderate to severe adult acquired flatfoot deformity that offers comparable short-term clinical and radiographic outcomes with acceptably low complications. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Medial Structure Injury During Suture Button Insertion Using the Center-Center Technique for Syndesmotic Stabilization.

BACKGROUND: The center-center technique for syndesmosis fixation has been described as an improved and reliable technique for proper reduction of the syndesmosis during ankle fracture repair. Concurrently, the use of flexible fixation with a suture button is becoming an established means of syndesmosis stabilization. The purpose of this cadaveric study was to assess for medial structure injury during the placement of a suture button using the center-center technique for ankle syndesmosis repair at 3 insertion intervals. METHODS: Simulated open syndesmosis repair was performed on 10 cadaveric specimens. Three intervals were measured at 10 mm, 20 mm, and 30 mm proximal to the level of the distal tibial articular surface along the fibula. Proper longitudinal alignment of the center-center technique was completed under fluoroscopic guidance and was marked on the medial aspect of the tibia. The 3 intervals were drilled in the appropriate technique trajectory. The suture button was subsequently passed through each drill-hole interval. A single observer used a digital caliper to measure the distance from each suture button aperture with respect to the tibialis anterior tendon, tibialis posterior tendon, and greater saphenous vein and nerve. RESULTS: A total of 30 interval measurements (10 cadavers with 3 suture button segments each) were used for data analysis. Direct impingement on the greater saphenous vein was seen in 11 of 30 (36.6%) interval measurements. Six of the 11 (54.5%) observed saphenous structure impingement events occurred at the 10-mm drill hole. CONCLUSION: The results of the present study suggest that the use of the center-center technique for syndesmosis repair with suture button fixation risks preventable injury to the greater saphenous neurovasculature. CLINICAL RELEVANCE: To understand the medial ankle anatomy, as it pertains to insertion of flexible syndesmotic fixation in a cadaveric model, to aid in prevention of clinical iatrogenic injury.

Predicting Failure of Nonoperative Treatment for Insertional Achilles Tendinosis.

Nonoperative treatment for midportion Achilles tendinosis is well defined by the literature. Multiple modalities are described for the management of insertional Achilles pathology, but no consensus exists regarding efficacy. Surgical intervention for insertional Achilles tendinosis (IAT) is successful greater than 80% of the time. Our objective was to risk stratify patients who would fail nonsurgical management of IAT and thus benefit progressing to surgery. We reviewed the records of 664 patients with IAT. The cohort was 53% male and 80% obese. Mean age was 53.7 years (standard deviation 14.7 years). Average duration of symptoms was 10.4 months (standard deviation 28 months). Of the parameters collected, 4 were found to correlate with failing nonoperative treatment: visual analog scale, limited ankle range of motion, previous corticosteroid injection, and presence of Achilles tendon enthesophyte. We found that as the number of risk factors increased so did the chance of failing nonoperative treatment. With all 4 parameters, chance of failing conservative treatment was only 55%. Thus, nonoperative management should be exhausted until surgery is the only remaining option. However, the presence of one of the aforementioned risk factors can aid a surgeon in the decision to pursue surgery in the appropriate clinical scenario. LEVELS OF EVIDENCE: Level IV: Retrospective Case series.

Medial Double Arthrodesis: Technique Guide and Tips.

The triple arthrodesis procedure remains the historical standard to treat complex hindfoot pathology. However, in recent data, the medial double arthrodesis has been documented to provide similar benefit with decreased complication rates compared with the triple arthrodesis. Therefore, increased interest in this procedure for the treatment of complex hindfoot pathologies has ensued. We describe the technical components of the medial double arthrodesis.

Content Relevance of the Foot and Ankle Ability Measure in Patients With Achilles Tendon Diseases.

BACKGROUND: The Foot and Ankle Ability Measure (FAAM) is among the most widely utilized and best psychometrically supported lower extremity-specific patient-reported outcome measures. However, its content relevance has never been directly subjected to patient assessment. METHODS: This was an institutional review board-approved, prospective, cross-sectional study of 75 patients with Achilles tendon diseases who ranked the relevance of the FAAM's items and subscales as 1 = Not relevant, 2 = Somewhat relevant, or 3 = Very relevant. Substantial content relevance was indicated by a minimum mean item or subscale score of 2.0. Nonsurgical and surgical subgroups were compared. RESULTS: At the whole group level, the mean score was above 2.0 for each individual item and subscale. Subgroup analysis revealed that the mean relevance was above 2.0 for each of the items and subscales with the exception of the "Personal Care" item, which nonsurgical patients ranked significantly lower than did surgical patients (mean = 1.74 vs 2.23, P = .02). Additionally, this was part of a general trend across items with more 95% confidence intervals crossing below 2.0 in the nonsurgical data set (15 items, 52%) than the surgical data set (1 item, 3%). CONCLUSION: These data confirm that the FAAM has substantial content relevance to patients with Achilles tendon diseases. However, it is unclear why the surgical subgroup consistently ranked items higher than did the nonsurgical subgroup. Future work should address how a patient's content relevance perception is influenced by the relative effects of their Achilles disease type and their perceived level of disease-related functional impairment. LEVELS OF EVIDENCE: Diagnostic, Level III.

Beaming in Charcot Arthropathy-Intramedullary Fixation for Complicated Reconstructions: A Cadaveric Study.

In the modern treatment of Charcot neuroarthropathy, beam screw fixation is an alternative to plate and screw fixation. Exposure is minimized for implantation, and this technique supports the longitudinal columns of the foot as a rigid load-sharing construct. A published data review identified a paucity of data regarding metatarsal intramedullary canal morphology relevant to beam screw fixation. The purpose of the present study was to describe metatarsal diaphyseal morphology qualitatively and quantitatively in an effort to provide data that can be used by surgeons when selecting axially based intramedullary fixation. Twenty fresh-frozen cadaveric below-the-knee specimens were obtained. The metatarsals were exposed, cleaned of soft tissue, and axially transected at the point of the narrowest external diameter. Next, a digital caliper was used to measure the size and shape of the diaphysis of the first through fourth metatarsals. The diaphyseal canal shape was categorized as round, oval, triangular, or pear. The widest distance between the endosteal cortical surfaces was measured. Triangular endosteal canals were only found in the first metatarsal, and the remainder of the metatarsal canals were largely round or oval. These data help to approximate the size of fixation needed to achieve maximal screw-endosteal purchase.

Experience with Navigation in Total Ankle Arthroplasty. Is It Worth the Cost?

Optimal placement of correctly sized total ankle replacement (TAR) implants is elemental to prolonging the working life. The negative mechanical effects of implant malalignment are well characterized. There is one FDA-approved navigated TAR system with limited but encouraging outcomes data. Therefore, its value can be estimated only based on benefits other than a proven clinical outcomes improvement over conventional systems. These include unique preoperative planning through 3-dimensional templating and virtual surgery and the patient-specific cut guides, which also reduce overall instrumentation needed for the case. To better inform this conversation, well-observed longitudinal outcomes studies are warranted.