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Category: Bunion Introduction/Purpose: Hallux valgus correction is often complicated by recurrence in the setting of inadequate soft tissue balancing. The etiology of recurrence is multifactorial, but a key factor is the quality of the medial capsulorrhaphy which is limited by the quality and strength of the soft tissues. These soft tissues are often attenuated with loss of integrity due to the longstanding bunion deformity. We hypothesize that the medial capsulorrhaphy augmented with a suture tape construct will create a stronger repair. Methods: 8 unmatched and 16 matched cadaveric foot specimens were prepared. None had bunion deformities. The 8 unmatched samples were tested to determine the strength of the native medial capsule. The 16 matched samples underwent a longitudinal medial capsulotomy, eminence resection and medial capsulorrhaphy with or without augmentation with a suture tape construct. The samples were then tested in a biomechanics lab to determine the strength of the medial capsulorrhaphy. Results: The mean maximum moment for the intact, capsular repair and suture tape groups were 2.19 ± 0.639 Nm, 0.225 ± 0.074 Nm and 0.968 ± 0.581, respectively, P

Category: Infection Introduction/Purpose: Postoperative infections after foot and ankle surgery can cause devastating outcomes for patients. Studies of postoperative infection rates in outpatient foot and ankle surgery range from 0.5-6.5%, with increasing numbers found in diabetic patient populations. The use of perioperative antibiotics in the prevention of postoperative infection in outpatient surgery is a topic that has often been discussed yet there remains considerable controversy. The authors hypothesize that there is no difference in postoperative infection rate or wound healing complications in patients who received postoperative oral antibiotics versus those that did not. Additionally, the authors sought to identify patient characteristics associated with postoperative infections or wound complications. Methods: Retrospective chart review of 649 elective outpatient foot and/or ankle surgery cases over a 2-year period performed by two fellowship trained foot and ankle surgeons at an academic medical center ambulatory surgical unit. All cases were included with at least one follow-up visit and no evidence of chronic wounds or infection. Those cases that did not have adequate follow up or if postoperative antibiotic treatment could not be determined were subsequently excluded. Analysis evaluated patients that received postoperative oral antibiotics (PAB) and those that did not receive postoperative oral antibiotics (NAB) to identify whether a difference in infection rate or wound healing complication were present. Patient demographics, medical comorbidities, BMI, smoking status, and tourniquet time were analyzed to identify contributing factors or comorbidities that may be more prevalent in those that developed postoperative infections in the PAB and NAB groups. Results: 633 operative cases were included in the study. The average age of patients in the PAB group and NAB group was equal (age 45 ± 17). The number of infections in PAB was 6, while the number of infections in NAB was 10 (3% vs. 2%, p = 0.60). The number of deep versus superficial infections and wound complications between the two groups was not statistically significant. Patients that developed infections versus those that did not were older (average age 55 vs. 45, p = 0.02), demonstrated a higher prevalence of hypertension (44% vs. 17%, p = 0.01), and a history of neoplasm (19% vs. 2%, p < 0.01). No significant difference was found between groups based on BMI, diabetes, tourniquet time, or smoking status. Conclusion: There are limited studies published on the efficacy of routine postoperative antibiotics in outpatient foot and ankle surgery, despite a majority of surgeons (75%) reporting using postoperative antibiotics.2 The present study suggests there is no benefit to prescribing postoperative oral antibiotics in an outpatient surgery setting. Additionally, older patients, patients with hypertension, and patients with a history of neoplasm made up a larger percentage of patients in the postoperative infection group. BMI, diabetes, tourniquet time and smoking status did not have a significant difference in postoperative infections between the PAB group and NAB group.

Category: Midfoot/Forefoot, Trauma Introduction/Purpose: Lisfranc injuries occurring between the medial cuneiform and base of the 2nd metatarsal require anatomic fixation. Suture button and screws are standard techniques for fixation, but the screw may decrease physiologic motion, whereas suture buttons may cause increased soft tissue irritation and iatrogenic cartilage damage. Potential benefits of the InternalBrace include physiologic motion, decreased iatrogenic damage, collagen ingrowth, limited bony erosion and decreased soft tissue irritation. In light of these potential benefits, no studies have investigated the biomechanical properties of the InternalBrace in a Lisfranc injury model. However, it is unknown whether there is significant difference in the biomechanical properties of the IB compared to the screw, or SB during load to failure, and cyclical loading. Methods: Three groups of sawbones were fixed together with either a 3.5 mm screw, SB, or IB, composed of a curved button, fibertape, and 4.75 mm biotenodesis screw. Sawbone constructs were held in a mechanical testing system (Model 809, MTS Systems Corp, Minneapolis MN). The first three groups of 10 were loaded in axial tension at 0.5mm/sec until failure to determine load-displacement data. Yield, stiffness, ultimate strength (US), yield energy, post-yield energy and ultimate strength energy were calculated. Three more groups of 8 constructs were loaded in-vitro at cyclical physiologic loads until displacement of 1.5 mm occurred. Constructs were first loaded for 10,000 cycles at 69 N (estimate for 50% body weight or assisted walking). Surviving specimens were loaded at 138 N (normal walk) for an additional 10,000 cycles and then 207 N (jog) for an additional 10,000 cycles. Displacement was recorded. The biomechanical properties were then compared between groups. Results: When loaded in axial tension at 0.5mm/sec until failure, the screw was found to be the stiffest construct (2,240 N/mm), while the InternalBrace (200 N/mm) was stiffer than the suture button (133 N/mm). Qualitatively, the InternalBrace was also found to hold load more consistently and for larger displacement prior to failure when compared to the suture button. Cyclic loading was performed with 10,000 cycles of 69 N, 138 N, and 207 N. The screw had the greatest resistance to fatigue. The InternalBrace maintained stiffness as well or better than the suture button, but the fatigue life was shorter than that of the suture button. Conclusion: To our knowledge, the biomechanical properties of the IB have not been compared to screw and SB for ligamentous lisfranc injuries. This study gives valuable information about the mechanical integrity of InternalBrace and supports continued use. However, further studies are warranted before making conclusions regarding early weight bearing.

Category: Ankle Arthritis Introduction/Purpose: Most current total ankle arthroplasty (TAA) designs attempt minimal bone resection and depend on bone ingrowth for long term survival. The arthritic process may cause subchondral bone cysts (SBCs), which could influence the available bone stock of the already limited distal tibia and talus. The prevalence or pattern of SBC formation in ankle arthritis has not been described. Furthermore, the ability of standard radiographs identifying and quantifying SBC formation is unknown. The purpose of our study is to define the prevalence and patterns of periarticular SBCs in the arthritic ankle and determine the efficacy of radiographs to identify SBCs. We hypothesized that the prevalence of SBCs is greater than determined from radiographs and that SBCs often extend beyond standard cuts for some TAA implants. Methods: We identified patients who presented with end-stage ankle arthritis and had pre-operative weight bearing x-rays and CT or MRI. Demographic data was obtained for each patient. Radiographs were reviewed to determine coronal plane deformity (varus/valgus), as well as the qualitative and quantitative presence of SBCs. The tibia and talus were divided into 6 zones: 1) antero-medial, 2) antero-lateral, 3) centro-medial, 4) centro-lateral, 5) postero-medial, and 6) postero-lateral. The same zones were used when evaluating CT or MRI. SBCs were measured to determine volume. The evaluation of all x-rays and CT/MRI’s was performed independently by three foot and ankle trained orthopaedic surgeons. We determined SBCs that extended >5 mm from the subchondral bone to be significant. We defined diffuse SBCs to be present in three or more zones in either the tibia or talus. Intra and inter-observer reliability was determined. Results: Ninety-five patients were included in our study. The average age was 69.3 years and 69% were male. Definitive treatment included 69 (73%) TAA and 26 (27%) ankle fusions. Neutral alignment occurred in 12%, congruent varus 15% and valgus 0%, and incongruent varus 54% and valgus 19%. Radiographs identified SBCs in 46% of patients and CT/MRI identified SBCs in 92% (p < 0.05). Cysts were present in the distal tibia 26% anterolateral, 17% anteromedial, 17% centrolateral, 17% posterolateral, 15% centromedial, and 9% posteromedial. Cysts were present in the talus 26% centromedial, 19% centrolateral, 19% posterolateral, 14% anterolateral, 12% anteromedial, and 10% posteromedial. 38% of the patients had diffuse SBCs. 52% of the cysts extended beyond 5 mm on either the distal tibia or talar dome. Conclusion: Our study suggests that SBCs are common in end stage ankle arthritis and may be diffuse and extend beyond standard cuts for TAA. Poor residual bone stock could compromise implant longevity and may explain early failures. Radiographs and coronal plane deformity are poor predictors for identifying extent, size, and location of SBCs. The authors recommend CT scans for all patients considered for TAA for preoperative planning for bone grafting, altering bone cut height, implant selection, or determining if the bone stock is suitable for TAA. Further study is needed to determine adequate bone stock for TAA.

Category: Ankle Introduction/Purpose: Numerous treatment modalities are in use today to treat symptomatic osteochondral lesions in the ankle; however, there are ongoing challenges with the treatment of certain types of lesions and concern regarding the long-term effectiveness of current common techniques. Methods: The purpose of this study was to collect mid and long-term clinical outcomes of pain, function, and activity level (VAS, SF-12, FAAM ADL, FAAM sports) Single-arm, multi-center study collected outcomes prospectively in standard clinic patients who would be undergoing or who had previously undergone treatment with DeNovo NT. The main exclusion criteria were high surgical risk, clinically diagnosed autoimmune diseases, or an active joint infection; all other patients receiving DeNovo NT could be approached for the study. The outcome analysis for this abstract focused on enrolled subjects’ final follow-up to date. Results: Clinical outcomes have been prospectively collected for 24 subjects with a total of 48 months follow-up. Twenty four of the treated lesions were located on the talus, none on the tibia. Out of the 24 patients, 23 had a single lesion and 1 had more than one. The average lesion size was 108.1 mm +/- 60.0 [23]. The Hepple classification was used to categorize each lesion. Interestingly, 19/24 were classified as 3 or higher. Cartilage ICRS was also used for classification. Out of the subjects, 23/24 were ICRS grade 3 or 4. There was also a concomitant procedure for 22/24 patients. Pre and post op VAS scores of 47.5 (+/- 23.1) and 12.2 +/- 17.8. SF-12 scores pre and post of 38.0 +/- 8.5 and 50.1 +/- 8.2. FAAM ADL’s pre and post 60.4 +/- 16.3 and 90.4 +/-11.8. FAAM sport scale scores pre and post 28.8 +/- 16.7 and 74.5 +/- 22.4. all outcome measures were statistically significant. Conclusion: Four year complete data is a challenge in this particular clinical population. This data set encompasses symptomatic osteochondral lesions of the talus treated with particulated juvenile cartilage allograft. The outcomes reflect an improvement in symptoms and patient satisfaction when treated with this technique. Based on these final outcome measures (V AS, SF-12, FAAM ADL’s, FAAM sport scale score) and satisfaction, it can be concluded that this is a viable option to get patients back to their pre-injury state.

Category: Midfoot/Forefoot Introduction/Purpose: Clinical decisions are often made based on the measurements of foot radiographs. Orthopaedic patients who have had lower extremity trauma or surgery are often given different weight bearing conditions including non-weight bearing, touch-down weight bearing, partial weight bearing (of various percent of body weight), and weight bearing as tolerated. However, it is largely unknown how these various weight bearing conditions alter specific parameters of foot radiographs. As such, the purpose of this study was to determine whether percent weight bearing influences radiographic measurements of the foot on anteroposterior (AP) and lateral radiographs? Methods: A total of 20 healthy subjects had AP and lateral radiographs of the foot under five weight bearing conditions (non-weight bearing, 10% body weight, 25% body weight, 50% body weight, and 100% body weight). Measurements were then made of hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), talonavicular coverage angle (TNCA), talo-calcaneal angle (TCA), forefoot width, LisFranc distance, cuboid height to ground (CHG), and talo-1st metatarsal angle (TMA) of each weight bearing condition. Statistical differences of each measurement for each weight bearing condition were then determined. Measurements were made by a radiologist and orthopaedic surgeon and inter-observer reliability determined for each measurement. For each radiographic measurement, a single factor ANOVA determined whether measurements were different between non-weight bearing, touchdown weight bearing, 25% weight bearing, 50% weight bearing, and 100% weight bearing. When a significant difference was detected, a post-hoc Tukey’s determined which categories of weight bearing were different. Results: The inter-observer reliability determined by the intraclass correlation coefficient was excellent to good in all measurements except for the TCA which was fair. For measurements made on the AP radiographs of the foot, the measurements that changed with percent weight bearing were the TNCA (p = 0.0009) and TCA (p = 0.0446) (Table 1). Weight bearing did not change the HVA (p = 0.2564, IMA (p = 0.1698), forefoot width (p = 0.2431), or LisFranc distance (p = 0.9854). For measurements made on the lateral radiographs of the foot, the measurement that changed with percent weight bearing was the CHG (p = 0.006). Weight bearing did not change the TMA (p = 0.9889). Conclusion: This study demonstrates a flattening of the medial arch with increasing percent body weight applied to a foot. This results in an increase in the TNCA as well as a decrease in the CHG. In addition, increasing percent body weight to the foot increases the hindfoot alignment. However, percent body weight does not alter measurements of the forefoot. Percentage body weight increase may not influence clinical preoperative/non-operative treatment as much as we expect; however, our findings do show that certain parameters increase with increasing weight bearing.

Category: Sports Introduction/Purpose: Subtle Lisfranc ligamentous injuries are difficult to diagnose and magnetic resonance is becoming a useful tool. The purpose of this study is to evaluate the efficacy of magnetic resonance (MR) imaging for the diagnosis of injuries of the Lisfranc ligament complex. Methods: The radiology database was searched between Jan 1, 2010 and Mar 10, 2015 to identify patients over the age of 18 years who had MR imaging of the foot for suspected injury of the Lisfranc ligament complex. MR images were reviewed by 2 fellowship trained musculoskeletal radiologists, whom were blinded to the original radiology reports. Findings were categorized as: no injury or injury present. Injury was deemed to be present if 2 of the 3 components of C1-M2 ligament showed disruption or signal alterations on T1 and T2 weighted images. Disagreements were resolved by consensus. Correlation was made with surgical findings whenever performed. In patients not undergoing surgery, the presence or absence of injury was determined by clinical examination performed by an orthopedic surgeon and follow-up. Sensitivity, specificity, positive predictive value(PPV), and negative predictive value (NPV) of MR for diagnosis of Lisfranc ligament complex injury was determined. Results: Of 60 patients, 9 were excluded due to a lack of follow-up. Lisfranc injury was determined to be present on MR in 26 patients and 18 underwent surgery. Injury was confirmed in 16, and 2 were intact. 2 patients underwent closed reduction and were clinically determined to be injured. 6 of the injured 26 patients were sprained and not injured/torn on clinical evaluation. Of the 25 patients determined to have no injury on MR, 24 were intact clinically. 1 patient had a Lisfranc injury on follow-up. Sensitivity, specificity, PPV and NPV of MR for detection of significant Lisfranc injury were 94.7% (CI: 73.9% to 99.9%), 75% (CI: 56.6% to 88.5%), 69.2% (CI: 55% to 80.5%) and 96% (CI: 77.9% to 99.4%) respectively. Conclusion: MR has a high sensitivity and negative predictive value for diagnosis of injury to the Lisfranc ligament complex. MR of the foot should be considered in patients with clinical suspicion of injury to the Lisfranc ligament complex, and it is highly accurate in excluding such injuries.

Category: Surgical complications Introduction/Purpose: For patients undergoing elective foot or ankle surgery deep vein thrombosis is a recognised risk with morbidity.The literature is often based on a retrospective review of the clinical notes which can be misleading. Surveillance has not been done in the past .Our concern was that the true incidence of DVT may have been underreported and silent DVTs are possible . The study prospectively determines the prevalence of DVT in low risk patients who are non weight bearing for 6 weeks post operatively by having patients undergo clinical detection as well as high resolution ultrasound to determine the presence and extent of deep vein thrombosis (DVT) in the patients operated leg at 2 weeks and 6 weeks after surgery. Methods: 197 patients undergoing elective (i.e. not trauma or achilles ruptures) foot or ankle surgery requiring a period of 6 weeks non weight bearing post operatively were selected for the study over a 2 year period. 83 patients were excluded as being high risk for DVT based on recognised criteria. The remaining 114 patients were included in the study as they were low risk for DVT. All 114 patients were assessed clinically at 2 weeks and 6 weeks post op for the possibility of DVT and this was recorded.The patients were then sent for high resolution U/S scans on the affected leg at 2 and 6 weeks after the surgery . A middle frequency (4-9 MHz) transducer was used for the study, and a lower frequency transducer for obese or swollen legs. The scans were performed at the Vascular Lab at our Institution which performs over 10000 scans annually. Results: 114 patients were in the study. 71 Females and 43 males with average age 52 years . The incidence of DVT was 24.56% (28/114). Of the 28 positive scans, 22 (79%) had no clinical symptoms or signs of DVT. 20/28 (71%) DVTs were diagnosed at the 2 week scan and 15 of these had no symptoms or signs of DVT. 8/28 (29%) patients had clear scans at 2 weeks and positive scans at 6 weeks.In this late onset group 7/8 had no symptoms or signs of a DVT. Only 5% (6/114) patients had symptoms or signs of DVT. The incidence of DVT in the first 2 weeks after surgery was 17.5%. Of the remaining 94 patients, 8.5% developed a DVT after 2 weeks. Conclusion: In low risk patients who are non weight bearing for 6 weeks after elective foot or ankle surgery the prevalence of DVT (25%) is significantly higher than the literature suggests and the majority of patients 79% (22/28) had no symptoms or signs of DVT to assist in the diagnosis. The majority of DVT’s occurred in the first 2 weeks after surgery however 29% of the total number of DVTs occurred between week 3 and week 6 non weight bearing.