Enhancing precision in osteochondral lesions of the talus measurements and improving agreement in surgical decision-making using weight-bearing computed tomography and distance mapping.

PURPOSE: Weight-bearing computed tomography (WBCT) enables the creation of a three-dimensional (3D) model that represents the ankle morphology in a standing position. Distance mapping (DM) is a complementary feature that uses color coding to represent the relative intraarticular distance and can be used to outline intraarticular defects. Consequently, DM offers a novel approach to delineating osteochondral lesions of the talus (OLT), allowing for the quantification of its surface, volume and depth. The reliability of DM for OLT measurements has yet to be thoroughly evaluated. This study primarily aims to determine the reliability of DM in measuring the surface, depth and volume of OLT. A secondary objective is to ascertain whether measurements obtained through DM, when integrated with a predefined treatment algorithm, can facilitate consensus among surgeons regarding the optimal surgical intervention. METHODS: This cohort comprised 36 patients with 40 OLTs evaluated using WBCT and DM. Two raters used DM to determine the lesion boundary (LB) and lesion fundus (LF) and calculate the lesion depth, surface and volume. The raters were asked to choose between bone marrow stimulation, autologous matrix-induced chondrogenesis and osteochondral transposition based on the measurement. Inter-rater and intra-rater agreement was measured. RESULTS: Interclass correlation of the lesion's depth surface produced an excellent inter-rater and intra-rater agreement of 0.90-0.94 p < 0.001. Cohen's κ agreement analysis of the preferable preoperative plan produced a κ = 0.834, p < 0.001, indicating a near-perfect agreement. CONCLUSION: WBCT-based 3D modules and DM can be used to measure the lesion's surface, depth and volume with excellent inter-rater and inter-rater agreement; using this measurement and a predetermined treatment algorithm, a near-perfect inter-rater agreement for the preoperative planning was reached. WBCT in conjunction with AI capabilities could help determine the type of surgery needed preoperatively, evaluate the hindfoot alignment and assess if additional surgeries are needed. LEVEL OF EVIDENCE: Level III.

Axial rotation analysis in total ankle arthroplasty using weight-bearing computer tomography and three-dimensional modeling.

BACKGROUND: Post-operative alignment is the most critical indicator for a successful total ankle arthroplasty (TAA). Total ankle malrotation is associated with an increased risk for polyethylene wear and medial gutter pain. Currently, there is no consensus on the correct way to measure the alignment of the tibial and talar component rotations in the axial plane. In the current study, the post-operative analysis system was assessed using weight-bearing computer tomography and a three-dimensional (3D) model. The purpose of the study was to assess the inter-observer and intra-observer agreement of this system. MATERIAL AND METHOD: Four angles were measured by two raters independently in two separate readings: posterior tibial component rotation angle (PTIRA), posterior talar component rotation angle (PTARA), tibia talar component axial angle (TTAM), and tibial component to the second metatarsal angle (TMRA). Agreement analysis was quantified according to the interclass coefficient. RESULTS: Sixty TAAs across 60 patients were evaluated. A good inter-observer agreement and intra-observer agreement when measuring the PTIRA, PTARA, and TTAM angles was observed along with an excellent inter-observer agreement and intra-observer agreement when measuring the TMRA angle. CONCLUSION: In conclusion, the current 3D model-based measurement system demonstrates good to excellent inter and intra-agreement. According to these results, 3D modelling can be reliably used to measure and assess the axial rotation of TAA components. LEVEL OF EVIDENCE: Level 3 retrospective study.

Reconstruction of a missing or insufficient distal fibula in the setting of a total ankle replacement: The Milanese technique.

BACKGROUND: The presence of an intact distal fibula is reported as a prerequisite when considering total ankle replacement and its lack is usually considered a contraindication. The purpose of the study was to describe the results of a surgical technique to reconstruct the distal fibula (Milanese fibular reconstruction technique) in the setting of a total ankle replacement and insufficient fibula. METHODS: Retrospective analysis of 15 patients (15 ankles) who underwent rotational fibular reconstruction technique with minimum follow-up of 24 months. Patients were evaluated preoperatively and at the last follow-up with AOFAS Ankle and Hindfoot score, VAS pain scale, SF-12 and range of motion. Standard weightbearing radiographs were used for radiographic assessment. RESULTS: The average of all clinical scores significantly improved (P<.001). The average radiographic parameters showed a neutral alignment. No cases of reabsorption of the new lateral malleolus were observed even in cases with complications that accounted for 2 superficial wound infection and 2 deep infections. CONCLUSIONS: The Milanese fibular reconstruction technique can successfully reestablish a lateral strut and in the setting of an ankle prosthesis in patients with an insufficient fibula.

Range of motion of foot joints following total ankle replacement and subtalar fusion.

BACKGROUND: In severe cases of ankle and subtalar arthritis, arthrodesis of the subtalar joint is performed in combination with ankle arthroplasty. In these special cases gait analysis reveals real motion at the replaced tibiotalar joint. METHODS: Twenty-three patients affected by ankle and subtalar arthritis, treated either with a 3-component or a 2-component prosthesis in combination with subtalar arthrodesis, were clinically evaluated preoperatively and at a minimum of 1-year follow-up. Gait analysis was performed postoperatively using a multi-segment foot protocol. Foot kinematics were compared to corresponding data from a healthy control group. RESULTS: Clinical scores significantly improved from preoperative to follow-up. The clinically measured passive ankle dorsiflexion/plantarflexion significantly improved at the follow-up. Patients' normalized walking speed and stride length were significantly lower than those in control. With exception of the ankle frontal-plane motion, sagittal-plane mobility of foot joints was about 50% than that in healthy joints. CONCLUSIONS: Improvement in clinical scores was found for both prostheses. Normal spatio-temporal parameters were not restored. In these patients, fusion of the subtalar joint appeared to be compensated by larger frontal-plane motion at the tibiotalar joint. LEVEL OF EVIDENCE: Level III- retrospective comparative study. The study was approved by the local Ethics Committee as protocol MAT (protocol registration at clinicaltrials.gov NCT03356951).

Learning curve assessment for total ankle replacement using the transfibular approach.

BACKGROUND: Total ankle arthroplasty is an increasingly effective option for the treatment of end-stage arthritis. One recent innovation utilizes a transfibular, lateral approach. Like any new system, there is likely a learning curve associated with its use. We analyzed a series of patients who received a total ankle arthroplasty via a transfibular approach to state if it is possible to identify and to evaluate effects of a learning curve in the use of this novel total ankle replacement system. METHODS: 76 consecutive patients meeting inclusion and exclusion criteria were retrospectively analyzed. All patients had a minimum of 24 months of follow-up. Intraoperative parameters, preoperative and postoperative subjective outcome scores, radiographic parameters, and complications were recorded and evaluated. RESULTS: There were significant learning curve effects on various surgical and postoperative parameters. Surgical time decreased with the curve stabilizing after the 16th patient. With regard to patient outcomes, a learning curve was identified for the VAS, AOFAS, and SF-12 MCS scores. The number of patients required to stabilize these curves were 21, 13, and 16, respectively. Alignment as measured by alpha and gamma angles also improved with experience, with the curves stabilizing at 18 and 15 patients, respectively. There was a larger number cases required for complication rates, with the curve stabilizing after the 39th patient. No significant learning curve was found for ankle ROM, SF-12 PCS, beta angle, tibio-talar ratio (TTR), or tibio-talar surface angle (TTS). CONCLUSIONS: This study demonstrates a significant learning curve with respect to operative time, patient outcomes, and radiographic parameters. Extrapolating this information, we urge surgeons to adequately familiarize themselves with any new implant through a training program in a high-volume center. LEVEL OF EVIDENCE: IV, case series.

Effectiveness of subtalar arthroereisis with endorthesis for pediatric flexible flat foot: a retrospective cross-sectional study with final follow up at skeletal maturity.

BACKGROUND: Pediatric flexible flatfoot is sometimes asymptomatic but it can rarely cause physical impairment, pain, and difficulty walking. We evaluated the radiographic effectiveness of intervention of subtalar arthroereisis with endorthesis for pediatric flexible flatfoot with final follow-up at skeletal maturity. METHODS: This is a retrospective cross-sectional study. 56 consecutive patients (112 feet) who underwent surgical treatment with subtalar arthroereisis for pediatric flexible flatfoot (mean age at final follow-up 15.5±1.2 years, 39.3% female) were enrolled. All the radiographic studies were performed in the hospital. Radiographs (standard weight-bearing radiographs of the foot with anteroposterior and lateral view) were used to measure lateral talocalcaneal angle (LTC), calcaneal pitch angle (CP), Meary's angle (MA), anteroposterior talonavicular angle (APTN), talonavicular uncoverage percent (TNU). Minimum follow-up was 18 months. Measures were assessed pre-operatively and at the final follow-up. Clinical and functional parameters were assessed at the final follow-up. RESULTS: Children who underwent surgical treatment with subtalar arthroereisis for pediatric flexible flatfoot exhibited a statistically significant improvement in all radiographic measurement parameters at the last follow-up at skeletal maturity (all, p<0.004). Mean follow-up was 40.1±23.6months. Clinical parameters were not correlated with the foot radiographic parameters at follow up period. CONCLUSIONS: Our results suggest that endorthesis in pediatric flexible flatfoot was effective for improving radiographic parameters at skeletal maturity. The amount of the morphologic correction at the end of the skeletal growth should be expected mainly for lateral tarso-metatarsal alignment and talo-navicular congruency (MA, APTN, TNU). LEVEL OF EVIDENCE: Level III, retrospective study.

Return to Sport After Arthroscopic Autologous Matrix-Induced Chondrogenesis for Patients With Osteochondral Lesion of the Talus.

OBJECTIVE: To determine the rate of return of patients to sport after arthroscopic autologous matrix-induced chondrogenesis (AT-AMIC) for outcomes 2 years after surgery. DESIGN: Retrospective observational cross-sectional study. SETTING: C.A.S.C.O.-Foot and Ankle Unit, Istituto Ortopedico Galeazzi, Milan, Italy. PATIENTS AND INTERVENTION: Twenty-six consecutive patients, 65.4% male (mean ± SD age: 33.7 ± 11.0 years), that underwent AT-AMIC procedure between 2012 and 2015 were selected retrospectively. From this population, only sporting patients at amateur's level were included. Arthroscopic autologous matrix-induced chondrogenesis was proposed in patients with pain and persistent disability. MAIN OUTCOME MEASURES: All patients were assessed with the American Orthopaedic Foot and Ankle Score (AOFAS), physical component score of the 12-Item Short Form Health Survey (SF-12), Halasi ankle activity score, and University of California, Los Angeles (UCLA) activity scale preoperatively and at 24 months postoperatively. RESULTS: Overall, 80.8% of the patient group returned to the same preinjury sport. The mean follow-up was 42.6 ± 10.9 months (range from 25 to 62 months). Significant differences were observed with reference to AOFAS, SF-12, Halasi, and UCLA scores at the last follow-up in patients who had undergone AT-AMIC (all, P < 0.001). CONCLUSIONS: A high percentage of patients return to their preinjury sport after AT-AMIC surgery.

Infections in primary total ankle replacement: Anterior approach versus lateral transfibular approach.

BACKGROUND: Total ankle replacement (TAR) represents an alternative to fusion for the treatment of end-stage ankle osteoarthritis. The aim of the present study was to retrospectively assess the frequency of infections between TARs with anterior and lateral transfibular approach at 12-months follow-up. METHODS: 81 TARs through an anterior approach and 69 TARs through a lateral approach were performed between May 2011 and July 2015. We compared surgical time and tourniquet time, as well as superficial and deep infections frequency during the first 12 postoperative months. RESULTS: In the anterior approach group, there were 3 (3.7%) deep infections and 4 (4.9%) superficial wound infections. In the lateral approach group, there were 1 (1.4%) deep infection and 2 superficial wound infections (2.9%). There were not statistically significant differences between the groups. There was a significant difference between anterior approach (115minutes) and lateral approach group (179minutes) in terms of surgical time (P<0.001). CONCLUSIONS: The frequency of superficial and deep periprosthetic infections during the first postoperative year was not significantly different in the lateral approach group compared to the anterior approach group, despite the significantly longer surgical time in the lateral transfibular approach group.

Reliability of the Phi angle to assess rotational alignment of the talar component in total ankle replacement.

BACKGROUND: The purpose of this study was to investigate the test-retest reliability of the Phi angle in patients undergoing total ankle replacement (TAR) for end stage ankle osteoarthritis (OA) to assess the rotational alignment of the talar component. METHODS: Retrospective observational cross-sectional study of prospectively collected data. Post-operative anteroposterior radiographs of the foot of 170 patients who underwent TAR for the ankle OA were evaluated. Three physicians measured Phi on the 170 randomly sorted and anonymized radiographs on two occasions, one week apart (test and retest conditions), inter and intra-observer agreement were evaluated. RESULTS: Test-retest reliability of Phi angle measurement was excellent for patients with Hintegra TAR (ICC=0.995; p<0.001) and Zimmer TAR (ICC=0.995; p<0.001) on radiographs of subjects with ankle OA. There were no significant differences in the reliability of the Phi angle measurement between patients with Hintegra vs. Zimmer implants (p>0.05). CONCLUSIONS: Measurement of Phi angle on weight-bearing dorsoplantar radiograph showed an excellent reliability among orthopaedic surgeons in determining the position of the talar component in the axial plane. LEVEL OF EVIDENCE: Level II, cross sectional study.

Adipose-derived stem cells in orthopaedic pathologies.

INTRODUCTION: To examine the current literature regarding the clinical application of adipose-derived stem cells (ADSCs) for the management of orthopaedic pathologies. SOURCES OF DATA: MEDLINE,SCOPUS, CINAHL and EMBASE (1950 to April 14, 2017) were searched by two independent investigators for articles published in English. Reviews, meta-analyses, expert opinions, case reports, mini case series and editorials were excluded. Furthermore, we excluded animal studies, cadaveric studies and in vitro studies. AREAS OF AGREEMENT: ADSCs seem to produce excellent clinical results. However, the length and modalities of follow-up in the different conditions are extremely variable. Nevertheless, it appears that the use of adipose-derived stem cells is associated with subjective and objective clinical improvements and minimal complication rates. AREAS OF CONTROVERSY: None of the studies identified is a randomized double-blinded trial, and most of the selected studies present major limitations, and different methods, confounding the results of our review. GROWING POINTS: It is necessary to conduct more and better studies to ascertain whether ADSCs really play a role in orthopaedic surgery with particular attention to ADSCs harvesting method, type of administration and the conditions treated. AREAS TIMELY FOR DEVELOPING RESEARCH: The current literature regarding the use of ADSCs for orthopaedic pathologies is limited. At present, long-term safety is the biggest challenge of ADSCs based regenerative medicine. LEVEL OF EVIDENCE: Level IV-Study of Level I, II, III, IV.

Tibial slope in total ankle arthroplasty: Anterior or lateral approach.

BACKGROUND: A new total ankle arthroplasty (TAA) system performed through a lateral approach provides direct visualization of the centre of rotation, allowing for accurate reconstruction of the joint alignment and less bone resection. Radiographic references are needed to describe deformities and plan the surgical procedures. The tibial slope is an important factor when treating malalignment. The aim of this study is to show if there is any difference regarding the post-operative tibial slope (ß angle) measurement comparing a fixed-bearing TAA through a lateral approach and a mobile-bearing TAA through an anterior approach. METHODS: The study included 217 ankles. Between May 2011 and April 2015, 77 patients underwent a TAA with a mobile-bearing implant through an anterior approach and 45 with a fixed-bearing implant through a lateral approach: in these patients the ß angle was measured 2 and 12 months postoperatively. 95 subjects with unilateral post-traumatic ankle arthritis composed the control group: in these patients we measured the anterior distal tibial angle (ADTA) of the controlateral, non arthritic tibiotalar joint. RESULTS: In the mobile-bearing group, the mean ß angle at 2 and 12 months postoperatively was 86.4±3.1 and 86.8±3.1 (p-value=0.12). In the fixed-bearing group, the mean ß angle at 2 and 12 months postoperatively was 83.1±5.4 and 83.9±6.5 (p-value=0.26). A statistically significant difference was found between the ß angle of the two groups. In the control group the mean ADTA was 84.9±2.5. A non-statistically significant difference was observed only between ß angle of the fixed-bearing group and the ADTA of the control group. CONCLUSIONS: Regarding the tibial slope, fixed-bearing TAA through a lateral approach showed a more anatomic placement. In contrast, ß angle in mobile-bearing group appeared more reproducible than fixed-bearing group.

Regeneration: AT-AMIC Technique: Limits and Indication.

Osteochondral lesion of the talus (OLT) is a commune cause of chronic ankle pain. Symptomatic lesions require surgical treatment. Currently, lesions with diameter less than 107.4 mm2 are treated with bone marrow stimulating technique with notable success rate. However, more extensive lesions show less predictable surgical results. Autologous matrix-induced chondrogenesis has proven to provide satisfactory medium and long-term results on OLTs. In the current review, we describe an all-arthroscopic technique and the Milan-Tel Aviv lesion assessment protocol.

Outcomes of Lateral Transfibular Approach for Total Ankle Replacement.

Total ankle replacement through a lateral transfibular approach with trabecular metal implants was introduced in 2012 and originally was advertised as a safer approach in terms of wound healing issues. Further studies showed no significant difference comparing anterior and lateral approach for infections and would healing issues, whereas the main advantage is deformity correction, acting on coronal, sagittal, and rotational deformities and on fibular length issues. It showed a survival rate of 97.7% at 5 years follow-up.

Significant Clinical Improvement After Arthroscopic Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus: A 5-Year Follow-Up.

PURPOSE: This study aims to evaluate the clinical outcomes of arthroscopic autologous matrix-induced chondrogenesis (A-AMIC) for osteochondral lesions of the talus (OLT) at 24 months and 60 months of follow-up. The secondary aim was to assess whether age, body mass index (BMI), and lesion surface affect outcomes. DESIGN: Sixty-three patients (32 males, 31 females) with a median age of 37 years [interquartile range (IQR): 25-48] were included. Preoperative and postoperative (24 months and 60 months) clinical outcomes were evaluated using a Visual Analog Score (VAS) for pain during walking, the American Orthopaedic Foot and Ankle Society (AOFAS), Short-Form Survey (SF-12), the Halasi, and the University of California, Los Angeles (UCLA) scores. Patients were categorized according to age, BMI, and lesion surface (1-1.5 cm2 and over 1.5 cm2). The effect of each category was evaluated. RESULTS: There were significant improvements in the VAS, AOFAS, SF-12, and UCLA, comparing the preoperative scores to the 60-month follow-up scores (P < 0.001). There were no significant differences in the above-mentioned outcomes between the follow-up periods. Patients older than 33 years had lower SF-12, Halasi, and UCLA scores (P = 0.005, 0.004, and <0.001, respectively). Overweight patients had lower VAS, SF-12, Halasi, and UCLA scores (P = 0.006, 0.002, 0.024, and 0.007, respectively). Lesion size was uninfluential. CONCLUSION: A-AMIC yielded clinical improvements at a minimum follow-up of 60 months in patients with symptomatic OLTs, with clinical improvement peaking in the first 2 years, followed by a plateau period. Increased age and BMI were significantly associated with inferior outcomes.

Surgical management of chronic proximal hamstring tendinopathy in athletes: a 2 to 11 years of follow-up.

BACKGROUND: Proximal hamstring tendinopathy typically afflicts athletes. The poor knowledge of this pathology can lead to late diagnosis and late treatment, which in chronic cases could be challenging. Surgical treatment could resolve the symptoms and could permit the return to full sport activity also in chronic cases. MATERIALS AND METHODS: We retrospectively evaluated 17 high-level athletes surgically treated for proximal hamstring tendinopathy. Symptoms lasted for an average of 23 months and were resistive to conservative treatment. RESULTS: The follow-up period averaged 71 months. Return to run without pain occurred at a mean of 2.4 months (range 1-4) after surgery. All patients returned to sports at their pre-symptom level at a mean of 4.4 months after surgery. Results were excellent in 15 patients (88 %) and good in two patients (12 %). No results were fair or poor. CONCLUSIONS: Surgical treatment to manage chronic proximal hamstring tendinopathy in high-level athletes showed excellent results in terms of relief from symptoms and return to previous sport level.

Needle Arthroscopic Subchondroplasty With Adipose-Derived Stem Cell Augmentation for the Treatment of Osteochondral Lesions of the Talus.

Needle arthroscopy has enjoyed a tremendous growth concerning the quality of intraoperative images due to technical innovation, resulting in innovative possibilities concerning concomitant minimally invasive procedures and treatment of osteochondral lesions of the talus (OLT). These lesions have increasingly been receiving scientific attention in the orthopaedic (sports) medicine field, and, as such, the quality of evidence-based treatment for them has developed substantially. Treatment of OLTs-and specifically subchondroplasty. OLTs may also be suitable for needle arthroscopic interventions. The purpose of the present technical note is, therefore, to present an all-arthroscopic needle arthroscopic technique, including subchondroplasty with adipose-derived stem cells augmentation for osteochondral lesions of the talus.

Three-Dimensional Distance Mapping to Identify Safe Zones for Lateral Column Lengthening.

BACKGROUND: Evans (E-LCL) and Hintermann LCL (H-LCL) lateral column lengthening osteotomies are standard surgical solutions for flexible, progressive collapsing feet. E-LCL is performed between the anterior and middle facets and endangers specific os calcis subtalar joint (OCST) subtypes without distinct facets. H-LCL is oriented between the posterior and middle facets and should be suitable for all OCSTs. Both osteotomies are associated with increased subtalar osteoarthritis, indicating iatrogenic damage. Distance mapping (DM) enables visualization of the relative distance between 2 articular surfaces represented by color patterns. This study aims to measure the safe zones for LCL using 3-dimensional (3D) models and DM; we hypothesize that it could be measured with high reproducibility. METHODS: Two raters categorized 200 feet across 134 patients into OCSTs based on the Bruckner classification. Four angles were measured independently. The proximal and distal extents of the posterior safe zone (PSZ) angles were determined for H-LCL osteotomies; similarly, the proximal and distal extents of the anterior safe zone (ASZ) angles were identified for E-LCL osteotomies. Consequently, the surface available for safe osteotomies were calculated. An interclass correlation was used to assess the agreement between the 2 raters. Additionally, analysis of variance and Mann-Whitney U test were used to compare the safe zones between OCSTs. RESULTS: The mean proximal and distal extents of the PSZ angles were 68 ± 7 and 75 ± 5 degrees from a line parallel to the lateral border of the calcaneus, respectively, and the proximal and distal extent of the ASZ angles were 89 ± 6 and 95 ± 5 degrees, respectively. There were no statistically significant differences between the OCSTs. Two raters measured the angles with good to excellent interrater and intrarater agreement. In 18 cases, we were unable to plan for H-LCL or E-LCL osteotomies. CONCLUSION: Distance mapping could be used to measure the safe zone, tailor a preoperative plan, and potentially reduce the risk for iatrogenic damage in LCL. 3D models and DM can increase the reliability of preoperative plans in bones with complex 3D structures. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Fast-Track for Total Ankle Replacement: A Novel Enhanced Recovery Protocol for Select Patients.

BACKGROUND: Enhanced recovery after surgery programs, also called fast-track protocols, were developed and successfully applied in the last decade for hip and knee reconstruction. Specific fast-track protocols have not yet been applied to ankle prostheses. The aim of the study was to develop and validate an enhanced recovery protocol for total ankle replacement (TAR) evaluating the clinical and radiographic results. We hypothesize that on the basis of well-defined pre- and postoperative characteristics, the current knowledge on ankle replacement, and referring to hip and knee reconstruction, it is possible to identify a "patient type" to be safely eligible to a Fast-Track Protocol with at least comparable results and without increasing the complications risk. METHODS: We identified 8 predictive variables that might affect the outcome of TAR. Those variables were the body mass index, the state of anxiety or depression, the functional preoperative status, ankle equinus, the coronal malalignment, the surgical time, the surgical accessory procedures, and the bone quality. These characteristics were evaluated for each patient with almost validated outcome tools attributing a specific score. Based on the score obtained, the patients were divided into 2 groups: the Standard Protocol group (Control Group) and the Fast-Track Protocol group (Study Group). The main difference between treatment of the 2 groups relates to the use of postoperative plaster casts: in the Fast-Track group the cast was removed the first day after surgery and walking was allowed in sports shoes assisted with crutches, whereas in the Standard Protocol group, the cast was removed after 3 weeks. Clinical and radiographic evaluation was performed for all patients preoperatively and postoperatively every 6 months. RESULTS: A total of 163 patients received a score between 1 and 5 and were included in the control group (Standard Protocol); 47 patients received a score of 0 and were allocated to the study group (Fast-Track Protocol). Clinically, except for the preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score, no statistically significant differences were recorded in the multiple comparisons between the 2 groups. No significant differences were found regarding complications. CONCLUSION: In selected patients, it is possible to apply an enhanced recovery protocol of rehabilitation, focused on immediate weightbearing and mobilization without any plaster or boot. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Reliability of Cone Beam Weightbearing Computed Tomography Analysis of Total Ankle Arthroplasty Positioning and Comparison to Weightbearing X-Ray Measurements.

BACKGROUND: The current reference standard for postoperative evaluation of total ankle arthroplasty (TAA) positioning, weightbearing radiography (WBXR), is subject to technical bias. Weightbearing cone beam computed tomography (WBCT) enables visualization of the foot's complex 3-dimensional (3D) structure under standing load. To date, no WBCT-based system for TAA positioning has been validated. The purpose of this study was to (1) assess TAA positioning using WBCT 3D models and (2) evaluate the agreement levels between 2 raters and thus evaluate the intermethod reliability with respect to WBXR. METHODS: Fifty-five consecutive patients were retrospectively reviewed. Two raters independently created a 3D WBCT model using dedicated software and recorded the following measurements: α angle, tibiotalar surface angle (TSA), hindfoot angle (HFA), tibiotalar ratio (TTR), ß angle, γ angle, and Φ angle. Measurements were repeated 2 months apart in similar, independent fashion and compared to WBXR. Interobserver, intraobserver, and intermethod agreements were calculated. RESULTS: All 7 measurements showed good to excellent intraobserver and interobserver reliability (ICC 0.85-0.95). The intermethod (WBCT vs WBXR) agreement showed good agreement for the γ angle (ICC 0.79); moderate agreement levels for the α angle, TSA angle, ß angle, and TTR (ICC 0.68, 0.69, 0.70, and 0.69, respectively); poor agreement for the HFA (ICC 0.25); and negative agreement for the φ angle (ICC -0.2). CONCLUSION: Position analysis of TAA using WBCT demonstrated good to excellent interobserver and intraobserver agreement and can be reliably used. Additionally, a negative to moderate agreement between standard WBCT and standard WBXR was found. LEVEL OF EVIDENCE: Level III, retrospective study.

Classification of the Os Calcis Subtalar Morphology in Symptomatic Flexible Pediatric Pes Planus Deformity Using Weightbearing CT and Distance Mapping.

BACKGROUND: The etiology of symptomatic pediatric pes planus (PP) deformity is unclear. Reduced os calcis subtalar joint (OCST) anterior facet morphology has been suggested to result in less support to the talar head and a higher propensity to develop PP deformity. Weightbearing computed tomography (WBCT) and distance mapping (DM) offer new opportunities to investigate PP deformity in general and the OCST specifically. The purpose of this study is to investigate the OCST morphology using DM and to classify PP subtalar subtypes with DM using Bruckner's A-D classification system. METHODS: Forty feet in 25 patients in a national referral center were evaluated for symptomatic PP deformity that failed nonoperative treatment. A WBCT scan was performed as part of the preoperative evaluation. Visualization of the distance distribution between the articulating surfaces of the subtalar joint was based on a DM technique. Intra- and interobserver agreement of the subtalar morphology was assessed using Bruckner's classification system. RESULTS: The mean age was 10.7 ± 1.4 years. The following mean ± SD and median ± ranges were semiautomatically measured for this group: Meary angle -21 ± 8, calcaneal inclination 15 ± 4 degrees, talar coverage angle 39 (range 32.6-49) degrees, and hindfoot moment-arm 16 ± 5 mm. Classifying subtalar morphology using DM yielded an excellent intra- and interobserver agreement. The individual percentages of each individual subtype were calculated: type A 5%, type B 48%, type C 4%, and type D in 44%. CONCLUSION: This study demonstrated excellent intraobserver and interobserver agreement in classifying the OCST using DM. A higher prevalence of types B and D was observed compared to types A and C in this PP cohort. LEVEL OF EVIDENCE: Level III, retrospective study.