The Biomechanical Role of the Deltoid Ligament on Ankle Stability: Injury, Repair, and Augmentation.

BACKGROUND: Deltoid ligament injuries occur in isolation as well as with ankle fractures and other ligament injuries. Both operative treatment and nonoperative treatment are used, but debate on optimal treatment continues. Likewise, the best method of surgical repair of the deltoid ligament remains unclear. PURPOSE: To determine the biomechanical role of native anterior and posterior components of the deltoid ligament in ankle stability and to determine the efficacy of simple suture versus augmented repair. STUDY DESIGN: Controlled laboratory study. METHODS: Ten cadaveric ankles (mean age, 51 years; age range, 34-64 years; all male specimens) were mounted on a 6 degrees of freedom robotic arm. Each specimen underwent biomechanical testing in 8 states: (1) intact, (2) anterior deltoid cut, (3) anterior repair, (4) tibiocalcaneal augmentation, (5) deep anterior tibiotalar augmentation, (6) posterior deltoid cut, (7) posterior repair, and (8) complete deltoid cut. Testing consisted of anterior drawer, eversion, and external rotation (ER), each performed at neutral and 25° of plantarflexion. A 1-factor, random-intercepts, linear mixed-effect model was created, and all pairwise comparisons were made between testing states. RESULTS: Cutting the anterior deltoid introduced ER (+2.1°; P = .009) and eversion laxity (+6.2° of eversion; P < .001) at 25 degrees of plantarflexion. Anterior deltoid repair restored native ER but not eversion. Tibiocalcaneal augmentation reduced eversion laxity, but tibiotalar augmentation provided no additional benefit. The posterior deltoid tear showed no increase in laxity. Complete tear introduced significant anterior translation, ER, and eversion laxity (+7.6 mm of anterior translation, +13.8° ER and +33.6° of eversion; P < .001). CONCLUSION: A complete deltoid tear caused severe instability of the ankle joint. Augmented anterior repair was sufficient to stabilize the complete tear, and no additional benefit was provided by posterior repair. For isolated anterior tear, repair with tibiocalcaneal augmentation was the optimal treatment. CLINICAL RELEVANCE: Deltoid repair with augmentation may reduce or avoid the need for prolonged postoperative immobilization and encourage accelerated rehabilitation, preventing stiffness and promoting earlier return to preinjury activity.

Outcomes Following Repair of Achilles Midsubstance Tears: Percutaneous Knotless Repair vs Open Repair.

BACKGROUND: Optimum treatment for acute Achilles tendon rupture results in high mechanical strength, low risk of complications, and return to preinjury activity level. Percutaneous knotless repair is a minimally invasive technique with promising results in biomechanical studies, but few comparison clinical studies exist. Our study purpose was to compare functional outcomes and revision rates following acute Achilles tendon rupture treated between percutaneous knotless repair and open repair techniques. METHODS: Patients 18 years or older with an acute Achilles tendon rupture, treated by a single surgeon with either open repair or percutaneous knotless repair, and more than 2 years after surgery were assessed for eligibility. Prospective clinical data were obtained from the data registry and standard electronic medical record. Additionally, the patients were contacted to obtain current follow-up questionnaires. Primary outcome measure was Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL). Secondary outcome measures were FAAM sports, 12-Item Short Form Health Survey (SF-12), Tegner activity scale, patient satisfaction with outcome, complications, and revisions. Postoperative follow-up closest to 5 years was used in this study. RESULTS: In total, 61 patients were included in the study. Twenty-four of 29 patients (83%) in the open repair group and 28 of 32 patients (88%) in the percutaneous knotless repair group completed the questionnaires with average follow-up of 5.8 years and 4.2 years, respectively. We found no significant differences in patient-reported outcomes or patient satisfaction between groups (FAAM ADL: 99 vs 99 points, P = .99). Operative time was slightly longer in the percutaneous knotless repair group (46 vs 52 minutes, P = .02). Two patients in the open group required revision surgery compared to no patients in the percutaneous group. CONCLUSION: In our study, we did not find significant differences in patient-reported outcomes or patient satisfaction by treating Achilles tendon midsubstance ruptures with percutaneous knotless vs open repair. LEVEL OF EVIDENCE: Level IlI, retrospective cohort study.

Broström Repair With and Without Augmentation: Comparison of Outcomes at Median Follow-up of 5 Years.

BACKGROUND: An augmented Broström repair with nonabsorbable suture tape has demonstrated strength and stiffness more similar to the native anterior talofibular ligament (ATFL) compared to Broström repair alone at the time of repair in cadaveric models for the treatment of lateral ankle instability. The study purpose was to compare minimum 2-year patient-reported outcomes (PROs) following treatment of ATFL injuries with Broström repair with vs without suture tape augmentation. METHODS: Between 2009 and 2018, patients >18 years old who underwent primary surgical treatment for an ATFL injury with either a Broström repair alone (BR Cohort) or Broström repair with suture tape augmentation (BR-ST Cohort) were identified. Demographic data and PROs, including Foot and Ankle Ability Measure (FAAM) with activities of daily living (ADL) and sport subscales, 12-Item Short Form Health Survey (SF-12), Tegner Activity Scale, and patient satisfaction with surgical outcome, were compared between groups, and proportional odds ordinal logistic regression was used. RESULTS: Ninety-one of 102 eligible patients were available for follow-up at median 5 years. The BR cohort had 50 of 53 patients (94%) completed follow-up at a median of 7 years. The BR-ST cohort had 41 of 49 (84%) complete follow-up at a median of 5 years. There was no significant difference in median postoperative FAAM ADL (98% vs 98%, P = .67), FAAM sport (88% vs 91%, P = .43), SF-12 PCS (55 vs 54, P = .93), Tegner score (5 vs 5, P = .64), or patient satisfaction (9 vs 9, P = .82). There was significantly higher SF-12 MCS (55.7 vs 57.6, P = .02) in the BR-ST group. Eight patients underwent subsequent ipsilateral ankle surgery, of which one patient (BR-ST group) was revised for recurrent lateral ankle instability. CONCLUSION: At median 5 years, patients treated for ATFL injury of the lateral ankle with Broström repair with suture tape augmentation demonstrated similar patient-reported outcomes to those treated with Broström repair alone. LEVEL OF EVIDENCE: Level II, retrospective cohort study.

Syndesmotic Suture Button Fixation Results in Higher Tegner Activity Scale Scores When Compared to Screw Fixation: A Multicenter Investigation.

BACKGROUND: Suture buttons and metal screws have been used and compared in biomechanical, radiographic, and clinical outcome studies for syndesmotic injuries, with neither implant demonstrating clear superiority. The aim of this study was to compare clinical outcomes of both implants. METHODS: Patients who underwent syndesmosis fixation at 2 separate academic centers from 2010 through 2017 were compared. Thirty-one patients treated with a suture button and 21 patients treated with screws were included. Patients in each group were matched by age, sex, and Orthopaedic Trauma Association fracture classification. Tegner Activity Scale (TAS), Foot and Ankle Ability Measure (FAAM), patient satisfaction score, surgical failure, and reoperation rates were compared. RESULTS: Patients who underwent suture button fixation had significantly higher TAS scores than those who underwent screw fixation (p < 0.001). There was no significant difference in FAAM ADL scores between cohorts (p = 0.08). Symptomatic hardware removal rates were similar (3.2% suture button cohort vs 9.0% in screw cohort). One patient (4.5%) underwent revision surgery secondary to syndesmotic malreduction after screw fixation, for a reoperation rate of 13.5%. CONCLUSION: Patients with unstable syndesmotic injuries treated with suture button fixation had higher mean TAS scores compared to patients treated with screws. Foot and Ankle Ability Measure and ADL scores in these cohorts were similar.Level of Evidence: Level 3 Retrospective Matched Case-Cohort.

Are Prospective Criteria or Objective Clinical Measures Utilized in Return to Play (RTP) Decision Making After Ankle Surgery? A Scoping Review.

Background: Manuscripts discussing return to play (RTP) following ankle surgery are common. However, the definition for RTP and the method by which it is determined remains unclear. The purpose of this scoping review was to clarify how RTP is defined following ankle surgery in physically active patients, to identify key factors informing RTP decision making (such as objective clinical measures), and make recommendations for future research. Methods: A scoping literature review was performed in April 2021 using PubMed, EMBASE, and Nursing and Allied Health databases. Thirty studies met inclusion criteria: original research following ankle surgery reporting at least 1 objective clinical test and documentation of RTP. Data were extracted for study methods and outcomes (RTP definition, RTP outcomes, and objective clinical tests). Results: The scoping review found studies on 5 ankle pathologies: Achilles tendon rupture, chronic lateral ankle instability, anterior ankle impingement, peroneal tendon dislocation, and ankle fracture. RTP criteria were not provided in the majority of studies (18/30 studies). In the studies that provided them, the RTP criteria were primarily based on time postsurgery (8/12) rather than validated criteria. Objective clinical outcome measures and patient-reported outcome measures (PROMs) were documented for each surgery when available. Both clinical outcomes and PROMs were typically measured >1 year postsurgery. Conclusion: In physically active patients who have had ankle surgery, RTP remains largely undefined and is not consistently based on prospective objective criteria nor PROMS. We recommend standardization of RTP terminology, adoption of prospective criteria for both clinical measures and PROMs to guide RTP decision making, and enhanced reporting of patient data at the time of RTP to develop normative values and determine when the decision to RTP is not safe. Level of Evidence: Level IV, scoping review.

Methods for Biomechanical Testing of Posterior Malleolar Fractures in Ankle Fractures: A Scoping Review.

BACKGROUND: The treatment of posterior malleolar fractures (PMFs) is debated, including the need for surgery and method of fixation. Recent literature has suggested that fracture pattern, rather than fragment size, may be an important predictor for ankle biomechanics and functional outcome. Biomechanical studies have been conducted to provide evidence-based treatment on the effects of fracture and fixation on contact pressure and stability. The objective of this scoping review is to summarize the methodologies used in biomechanical studies on PMFs and assess whether they are sufficient to test the need for surgery and method of fixation. METHODS: A scoping review of publications before January 2022 was performed. PubMed/Medline and Embase Ovid were searched for cadaver or finite element analysis (FEA) studies that created and tested the effects of PMFs in ankle fractures. Both cadaver and FEA studies were included. Data about fragment characteristics, mode of testing, and outcomes were charted by 2 persons from the study group. The data were synthesized when possible and compared. RESULTS: We included 25 biomechanical studies, including 19 cadaver studies, 5 FEA studies, and 1 cadaver and FEA study. Aside from the fragment size, few other fragment characteristics were reported. Mode of testing varied with different loads and foot positions. Strong conclusions on the effects of fracture and fixation on contact pressure and stability could not be made. CONCLUSION: Biomechanical studies on PMFs demonstrate wide variability in fragment characteristics and mode of testing, which makes it difficult to compare studies and draw conclusions on the need for surgery and method of fixation. Additionally, limited reporting of fragment measurements questions the applicability to clinical practice. The biomechanical literature on PMFs would benefit from the use of a standard classification and universal fragment measurements to match clinical injuries in future biomechanical studies. Based on this review, we recommend the Mason classification, which addresses the pathomechanism, and use of the following fragment measurements in all 3 anatomic planes when creating and describing PMFs: fragment length ratio, axial angle, sagittal angle or fragment height, and interfragmentary angle. The testing protocol needs to reflect the purpose of the study. CLINICAL RELEVANCE: This scoping review demonstrates wide methodological diversity of biomechanical studies. Consistency in methodology should enable comparison of study results, leading to stronger evidence-based recommendations to guide surgeons in decision making and offer PMF patients the best treatment.

Effect of Posterior Malleolar Fixation on Syndesmotic Stability.

BACKGROUND: Transsyndesmotic fixation with suture buttons (SBs), posterior malleolar fixation with screws, and anterior inferior tibiofibular ligament (AITFL) augmentation using suture tape (ST) have all been suggested as potential treatments in the setting of a posterior malleolar fracture (PMF). However, there is no consensus on the optimal treatment for PMFs. PURPOSE: To determine which combination of (1) transsyndesmotic SBs, (2) posterior malleolar screws, and (3) AITFL augmentation using ST best restored native tibiofibular and ankle joint kinematics after 25% and 50% PMF. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty cadaveric lower-leg specimens were divided into 2 groups (25% or 50% PMF) and underwent biomechanical testing using a 6 degrees of freedom robotic arm in 7 states: intact, syndesmosis injury with PMF, transsyndesmotic SBs, transsyndesmotic SBs + AITFL augmentation, transsyndesmotic SBs + AITFL augmentation + posterior malleolar screws, posterior malleolar screws + AITFL augmentation, and posterior malleolar screws. Four biomechanical tests were performed at neutral and 30° of plantarflexion: external rotation, internal rotation, posterior drawer, and lateral drawer. The position of the tibia, fibula, and talus were recorded using a 5-camera motion capture system. RESULTS: With external rotation, posterior malleolar screws with AITFL augmentation resulted in best stability of the fibula and ankle joint. With internal rotation, all repairs that included posterior malleolar screws stabilized the fibula and ankle joint. Posterior and lateral drawer resulted in only small differences between the intact and injured states. No differences were found in the efficacy of treatments between 25% and 50% PMFs. CONCLUSION: Posterior malleolar screws resulted in higher syndesmotic stability when compared with transsyndesmotic SBs. AITFL augmentation provided additional external rotational stability when combined with posterior malleolar screws. Transsyndesmotic SBs did not provide any additional stability and tended to translate the fibula medially. CLINICAL RELEVANCE: Posterior malleolar fixation with AITFL augmentation using ST may be the preferred surgical method when treating patients with acute ankle injury involving an unstable syndesmosis and a PMF ≥25%.

Summary Report of the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society's Symposium on Targets for Osteoarthritis Research: Part 1: Epidemiology, Pathophysiology, and Current Imaging Approaches.

This first of a 2-part series of articles recounts the key points presented in a collaborative symposium sponsored jointly by the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society with the intent to survey the state of scientific knowledge related to incidence, diagnosis, pathologic mechanisms, and injection treatment options for osteoarthritis (OA) of the foot and ankle. A meeting was held virtually on December 3, 2021. A group of experts were invited to present brief synopses of the current state of knowledge and research in this area. Part 1 overviews areas of epidemiology and pathophysiology, current approaches in imaging, diagnostic and therapeutic injections, and genetics. Opportunities for future research are discussed. The OA scientific community, including funding agencies, academia, industry, and regulatory agencies, must recognize the needs of patients that suffer from arthritis of foot and ankle. The foot and ankle contain a myriad of interrelated joints and tissues that together provide a critical functionality. When this functionality is compromised by OA, significant disability results, yet the foot and ankle are generally understudied by the research community. Level of Evidence: Level V - Review Article/Expert Opinion.

Summary Report of the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society's Symposium on Targets for Osteoarthritis Research: Part 2: Treatment Options.

This second of a 2-part series of articles recounts the key points presented in a collaborative symposium sponsored jointly by the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society with the intent to survey current treatment options for osteoarthritis (OA) of the foot and ankle. A meeting was held virtually on December 10, 2021. A group of experts were invited to present brief synopses of the current state of knowledge and research in this area. Topics were chosen by meeting organizers, who then identified and invited the expert speakers. Part 2 overviews the current treatment options, including orthotics, non-joint destructive procedures, as well as arthroscopies and arthroplasties in ankles and feet. Opportunities for future research are also discussed, such as developments in surgical options for ankle and the first metatarsophalangeal joint. The OA scientific community, including funding agencies, academia, industry, and regulatory agencies, must recognize the importance to patients of addressing the foot and ankle with improved basic, translational, and clinical research. Level of Evidence: Level V, review article/expert opinion.

Anterior Inferior Tibiofibular Ligament Suture Tape Augmentation for Isolated Syndesmotic Injuries.

BACKGROUND: The best operative construct and technique for treatment of isolated syndesmotic injuries is highly debated. The purpose of this study was to determine whether the addition of anterior inferior tibiofibular ligament (AITFL) suture repair or suture tape (ST) augmentation provides any biomechanical advantage to the operative repair of an isolated syndesmotic injury. METHODS: Twelve lower leg specimens underwent biomechanical testing in 6 states: (1) intact, (2) AITFL suture repair, (3) AITFL suture repair + transsyndesmotic suture button (SB), (4) AITFL suture repair + ST augmentation + SB, (5) AITFL suture repair + ST augmentation, and (6) complete syndesmotic injury. The ankle joint was subjected to 6 cycles of 5 Nm internal and external rotation torque under a constant axial load. The spatial relationship between the tibia, fibula, and talus was continuously recorded with a 5-camera motion capture system. RESULTS: AITFL suture repair and AITFL suture repair + ST augmentation showed no statistically significant change in fibula kinematics compared to the intact state. Compared to native, AITFL suture repair + SB showed increased fibular external rotation (+2.32 degrees, P < .001), and decreased tibiofibular gap (overtightening) (-0.72 mm, P = .007). AITFL suture repair + ST augmentation + SB also showed increased fibular external rotation (+1.46 degrees, P = .013). Sagittal plane motion of the fibula was not significantly different between any states. None of the repairs restored intact state talus rotation; however, the repairs that used ST augmentation reduced the talus external rotation laxity compared to the complete syndesmotic injury. CONCLUSION: AITFL suture repair and AITFL ST augmentation best restored the rotational kinematics and stability of the fibula and ankle joint in an isolated syndesmotic injury model. CLINICAL RELEVANCE: AITFL suture repair with or without ST augmentation may be a good operative addition or alternative to SB fixation for isolated syndesmotic disruptions.

Biomechanical Evaluation of Achilles Tendon Midsubstance Repair: The Effects of Anchor Angle and Position.

BACKGROUND: The percutaneous knotless repair technique for Achilles tendon ruptures utilizes a Percutaneous Achilles Repair System (PARS) device for suturing the proximal tendon and 2 suture anchors for fixing the sutures into the calcaneus. Determining the best position of the suture anchors may optimize the strength of this repair. METHODS: Twelve pairs of human ankle cadaveric specimens were randomly assigned to receive suture anchors placed at 45°, 90°, or 135° from the sagittal plane. The anchors were tensioned according to a protocol representing progressive, postoperative rehabilitation. Load, number of loading cycles, displacement, and mode of failure were recorded. RESULTS: With the anchors placed at 45°, 90°, and 135°, the ultimate failure loads were mean 265 ± 64 N, 264 ± 75 N, and 279 ± 40 N, and the total number of loading cycles were mean 459 ± 166, 466 ± 158, and 469 ± 110, respectively. The effect of anchor angle on failure load, number of loading cycles, and displacement was not statistically significant. Visually, the anchors at 45° and 90° demonstrated sutures cutting through the bone. CONCLUSION: We found no statistically significant difference in pullout strength between the 3 different anchor angles. Sutures cutting through the bone may be a concern with acute anchor angles. This suggests that a 135° anchor angle may result in a lower risk of tendon elongation with the percutaneous knotless repair technique. LEVELS OF EVIDENCE: Cadaveric laboratory study.

Evaluation of the Intact Anterior Talofibular and Calcaneofibular Ligaments, Injuries, and Repairs With and Without Augmentation: A Biomechanical Robotic Study.

BACKGROUND: Acute ankle sprains are common injuries. The anterior talofibular (ATFL) and calcaneofibular ligaments (CFL) are the most injured lateral structures. However, controversy exists on the optimal surgical treatment when the injury is both acute and severe or becomes chronic and unstable. Studies have evaluated the biomechanics of these ligaments, but no studies have robotically evaluated injury effects and surgical treatment of ATFL or ATFL and CFL injuries. PURPOSE: To quantitatively evaluate biomechanical effects of ATFL and CFL lesions, ATFL repair, ATFL and CFL repair, and augmentation of ATFL on ankle stability. STUDY DESIGN: Controlled laboratory study. METHODS: Ten nonpaired cadaveric ankles were tested using a 6 degrees of freedom robot. Each ankle underwent testing in the following states sequentially: (1) intact, (2) ATFL cut, (3) CFL cut, (4) ATFL repair + CFL cut, (5) ATFL repair + CFL repair, and (6) ATFL repair with augmentation with suture tape + CFL repair. Testing included 88 N anterior drawer and 5 N·m varus talar tilt tests at 0° and 30° of plantarflexion, and 88 N Cotton test at 0° of plantarflexion. RESULTS: After all surgical treatments ankles still had increased laxity compared with intact state testing, except after augmented ATFL repair + CFL repair in anterior drawer testing at 30° of plantarflexion (P = .393). Sectioning the CFL caused a significant increase in talar tilt compared with the ATFL cut state at 0° (P < .001) and 30° of plantarflexion (P < .001), but no increase in anterior drawer or Cotton tests. CONCLUSION: Complete native stability may not be attainable at time zero repair with the tested treatments. The option that best returned stability in anterior translation was augmented ATFL repair with nonaugmented CFL repair. The importance of the CFL as a primary ligamentous stabilizer for talar tilt was confirmed. CLINICAL RELEVANCE: Evaluating lateral ankle stability and treatment with a 6 degrees of freedom robot should help delineate optimal treatment options. Findings in this study show that none of the repair methods at time zero restored kinematics to the intact state. Of the tested states, the augmented ATFL repair with CFL repair was the best option for controlling anterior translation at time zero. The importance of addressing the CFL to correct talar tilt instability was suggested as was the importance of a period of immobilization before beginning protected rehabilitation. The benefit of ATFL repair augmentation with suture tape is in limiting the postoperative motion in an anterior drawer motion to just 0.5 to 1 mm, but there was no significant improvement to talar tilt even with CFL repair, suggesting that further consideration should be given to CFL augmentation in future studies.

Accessibility and Thickness of Medial and Lateral Talar Body Cartilage for Treatment of Ankle and Foot Osteochondral Lesions.

BACKGROUND: The purposes of this study were to determine (1) if cartilage thicknesses on the talar dome and medial/lateral surfaces of the talus were similar, (2) whether there was sufficient donor cartilage surface area on the medial and lateral talar surfaces to repair talar dome cartilage injuries of the talus, and (3) whether the cartilage surface could be increased following anterior talofibular ligament (ATFL) and sectioning of the tibionavicular and tibiospring portion of the anterior deltoid. METHODS: Medial and lateral approaches were utilized in 8 cadaveric ankles to identify the accessible medial, lateral, and talar dome cartilage surfaces in 3 conditions: (1) intact, (2) ATFL release, and (3) superficial anterior deltoid ligament release. The talus was explanted, and the cartilage areas were digitized with a coordinate measuring machine. Cartilage thickness was quantified using a laser scanner. RESULTS: The mean cartilage thickness was 1.0 ± 0.1 mm in all areas tested. In intact ankles, the medial side of the talus showed a larger total area of available cartilage than the lateral side (152 mm2 vs 133 mm2). ATFL release increased the available cartilage area on the medial and lateral sides to 167 mm2 and 194 mm2, respectively. However, only the lateral talar surface had sufficient circular graft donor cartilage available for autologous osteochondral transplantation (AOT) procedures of the talus. After ATFL and deltoid sectioning, there was an increase in available graft donor cartilage available for AOT procedures. CONCLUSION: The thickness of the medial and lateral talar cartilage surfaces is very similar to that of the talar dome cartilage surface, which provides evidence that the medial and lateral surfaces may serve as acceptable AOT donor cartilage. The surface area available for AOT donor site grafting was sufficient in the intact state; however, sectioning the ATFL and superficial anterior deltoid ligament increased the overall lateral talar surface area available for circular grafting for an AOT procedure that requires a larger graft. These results support the idea that lateral surfaces of the talus may be used as donor cartilage for an AOT procedure since donor and recipient sites are similar in cartilage thickness, and there is sufficient cartilage surface area available for common lesion sizes in the foot and ankle. CLINICAL RELEVANCE: This anatomical study investigates the feasibility of talar osteochondral autografts from the medial or lateral talar surfaces exposed with standard approaches. It confirms the similar cartilage thickness of the talar dome and the ability to access up to an 8- to 10-mm donor graft from the lateral side of the talus after ligament release. This knowledge may allow better operative planning for use of these surfaces for osteochondral lesions within the foot and ankle, particularly in certain circumstances of a revision microfracture.

Relationship Between Tibiotalar Joint Space and Ankle Function Following Ankle Surgery.

BACKGROUND: Joint-preserving procedures of the ankle may postpone the need for ankle arthrodesis (AA) or total ankle replacement (TAR). The challenge for the surgeon is to determine which patients may benefit from these joint-preserving procedures. We hypothesized that patents with less than 2 mm of ankle joint space on preoperative radiographs would report inferior outcomes following joint-preserving surgery compared with those with 2 mm or greater joint space. METHODS: Patients 18 years of age or older treated with joint-preserving ankle surgery with a minimum of 2 years of follow-up were considered for study inclusion. The ankle joint space was measured on standardized weightbearing preoperative radiographs. At follow-up, patients completed questionnaires including the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports subscales, the Short Form-12 (SF-12) Physical Component Summary and Mental Component Summary, the Tegner Activity Scale, and satisfaction with outcome. RESULTS: A total of 251 patients were included in the study. Forty-three patients had an ankle joint space of less than 2 mm. Compared with the 208 patients with an ankle joint space of 2 mm or greater, they had inferior FAAM ADL, FAAM Sports, and SF-12 Physical Component Summary scores (P = .001, P = .001, and P = .006, respectively). Additionally, a statistically significant positive correlation between joint space distance and the FAAM ADL (P = .012, r = 0.158), FAAM Sports (P < .001, r = 0.301), and SF-12 Physical Component Summary (P < .010, r = 0.163) scores was found. CONCLUSION: Patients with a preoperatively narrowed ankle joint space of less than 2 mm had significantly lower outcome scores following joint-preserving ankle surgery compared with patients with preserved ankle joint space. These results may assist clinicians in selecting patients who may benefit from ankle joint-preserving procedures, as well as counseling patients with a narrowed ankle joint space regarding expected outcome after joint-preserving ankle surgery. LEVEL OF EVIDENCE: Level II, prognostic comparative study.

Patient Reported Outcome Measures in the Foot and Ankle: Normative Values Do Not Reflect 100% Full Function.

PURPOSE: The primary purpose of this study was to determine normative values for foot and ankle ability measure (FAAM), activities of daily living (ADL), FAAM/foot and ankle disability (FADI) Sport, Tegner activity scale, SF-12 physical component summary (PCS) and mental component summary (MCS) in individuals who are representative of the "normal" adult population in the United States. The secondary purpose was to perform a confirmatory factor analysis (CFA) of ankle functional ability to provide evidence of reliability and validity of commonly used orthopaedic outcome scores. Our hypothesis was that normative values will differ based on patient characteristics and demographics, and that the selected commonly used foot and ankle outcomes scores will demonstrate acceptable reliability and validity estimates. METHODS: There were 271 persons in this study (101 women, 170 men, average age = 31.4 (SD = 15.1) years, average BMI = 25.9 (SD = 5.9)). Age, sex and BMI were documented. Comparisons of outcome scores were made between cohorts. CFA was performed to test factor structure of ankle functional ability. RESULTS: There was no significant difference in FAAM ADL between women and men (n.s.) or FAAM Sport (n.s.). Women had significantly higher SF-12 PCS (P = 0.001). Men had significantly higher SF-12 MCS (P < 0.001) and Tegner (P = 0.024). FAAM ADL, FAAM Sport and SF-12 PCS scores were significantly higher in people who did not have previous ankle surgery. Younger people and those with lower BMI had significantly higher ankle function. Reliability was excellent, and the CFA had excellent model fit demonstrating evidence of validity. CONCLUSIONS: This study revealed that normative values of foot and ankle outcome measures did not reflect 100% function and differed by sex, previous ankle surgery status, age and BMI. Individuals who did not have previous ankle surgery were younger, and had lower BMI and higher functional levels. Reliability was excellent, and the CFA model demonstrated excellent fit, providing evidence for validity, and lending support to use aggregated outcome measures as one scale. This study is unique in that it provides surgeons with normative ankle values in commonly reported outcome measures including the FAAM, FADI SF-12 and Tegner activity scale, in the normal population, based on BMI, age, gender and previous ankle surgery status. This information can be a very useful tool in the clinical setting for patient expectations counseling. In addition, surgeons and clinicians can feel confident using these outcome scores to assess their patients' progress through the continuum of care. LEVEL OF EVIDENCE: Level II.

Accuracy of MRI-Based Talar Cartilage Thickness Measurement and Talus Bone and Cartilage Modeling: Comparison with Ground-Truth Laser Scan Measurements.

OBJECTIVE: The purpose of this work was to compare measurements of talar cartilage thickness and cartilage and bone surface geometry from clinically feasible magnetic resonance imaging (MRI) against high-accuracy laser scan models. Measurement of talar bone and cartilage geometry from MRI would provide useful information for evaluating cartilage changes, selecting osteochondral graft sources or creating patient-specific joint models. DESIGN: Three-dimensional (3D) bone and cartilage models of 7 cadaver tali were created using (1) manual segmentation of high-resolution volumetric sequence 3T MR images and (2) laser scans. Talar cartilage thickness was compared between the laser scan- and MRI-based models for the dorsal, medial, and lateral surfaces. The laser scan- and MRI-based cartilage and bone surface models were compared using model-to-model distance. RESULTS: Average cartilage thickness within the dorsal, medial, and lateral surfaces were 0.89 to 1.05 mm measured with laser scanning, and 1.10 to 1.22 mm measured with MRI. MRI-based thickness was 0.16 to 0.32 mm higher on average in each region. The average absolute surface-to-surface differences between laser scan- and MRI-based bone and cartilage models ranged from 0.16 to 0.22 mm for bone (MRI bone models smaller than laser scan models) and 0.35 to 0.38 mm for cartilage (MRI bone models larger than laser scan models). CONCLUSIONS: This study demonstrated that cartilage and bone 3D modeling and measurement of average cartilage thickness on the dorsal, medial, and lateral talar surfaces using MRI were feasible and provided similar model geometry and thickness values to ground-truth laser scan-based measurements.

Use of Anatomical Landmarks in Ankle Arthroscopy to Determine Accuracy of Syndesmotic Reduction: A Cadaveric Study.

Background. The aim of this study was to determine the accuracy of ankle arthroscopy as a means for diagnosing syndesmotic reduction or malreduction and to determine anatomical landmarks for diagnosis. Methods. Six matched-pair cadavers (n = 12) with through-knee amputations were studied. Component parts of the syndesmosis and distal 10 cm of the interosseous membrane (IOM) were sectioned in each. The 12 specimens were divided into 2 groups: 6 specimens in the in-situ group fixed with suture button technique and 6 specimens in the malreduced group rigidly held with a 3.5-mm screw. Specimens were randomized to undergo diagnostic arthroscopy by 3 fellowship-trained foot and ankle orthopaedic surgeons in a blinded fashion. Surgeons were asked to determine if the syndesmosis was reduced or malreduced and provide arthroscopic measurements of their findings. Results. Of 36 arthroscopic evaluations, 34 (94%) were correctly diagnosed. Arthroscopic measurement of 3.5 mm diastasis or greater at the anterior aspect of the distal tibiofibular syndesmosis correlated with a posteriorly malreduced fibula. Arthroscopic evaluation of the Anterior inferior tibiofibular ligament (AITFL), IOM, Posterior inferior tibiofibular ligament (PITFL), lateral fibular gutter, and the tibia/fibula relationship were found to be reliable landmarks in determining syndesmotic reduction. An intraclass correlation coefficient (ICC) for interrater reliability of 1.00 was determined for each of these landmarks between 2 surgeons (P < .001). The ICCs between 2 surgeons' measurements and the computed tomography measurements were found to be 0.896 (P value < .001). Conclusions. Ankle arthroscopy is a reliable method to assess syndesmotic relationship when reduced in situ or posteriorly malreduced 10 mm. Levels of Evidence: Level V: Cadaveric.

Rasch Analysis of Reliability and Validity of Scores From the Foot and Ankle Ability Measure (FAAM).

BACKGROUND: The purpose of this study was to determine the reliability and validity of scores from the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports scales in patients who have a variety of ankle injuries. METHODS: All patients who underwent surgical treatment for an ankle injury and completed the FAAM ADL and Sport scales were included in this study (n = 456; 192 females, 264 males). The average age was 47.6 years (range, 18-79 years). The average time to follow-up was 3.8 years (range, 2.0-7.7 years). All data were collected prospectively and reviewed retrospectively. A reliability and validity analysis, utilizing the Rasch measurement model, a special case of item response theory (IRT), was conducted. RESULTS: Reliability was very good. For FAAM ADL, person reliability was 0.87 and item reliability was 0.99. For FAAM Sport, person reliability was 0.89 and item reliability was 1.0. Infit mean square (MNSQ) values, which assess internal scale validity, were examined. For FAAM ADL, items 11 (coming up on your toes) and 10 (squatting) were high (2.27 and 2.08, respectively). All other infit values were within the acceptable range of 0.5 to 1.7. For FAAM Sport, all infit values were within the acceptable range. Outfit MNSQ values, which assess the FAAM ADL and Sport rating scale function, were examined. Three items from FAAM ADL were beyond the acceptable range. Items 10 and 11 from FAAM ADL had high outfit MNSQ values (2.15 and 1.98, respectively). Item 19 (light to moderate work) item had a marginally low outfit MNSQ of 0.48. For FAAM Sport, all outfit values were within the acceptable range. CONCLUSION: There was very good evidence of the reliability and validity of FAAM ADL and FAAM Sport scores. Two FAAM ADL items may indicate the need for further scale development for use in a diverse surgical ankle population. LEVEL OF EVIDENCE: Level III, comparative series.