Amiethab Aiyer

Radiographic Correction Following Reconstruction of Adult Acquired Flat Foot Deformity Using the Cotton Medial Cuneiform Osteotomy

Background: The Cotton osteotomy has been used to correct residual forefoot supination in flexible flatfoot deformity reconstruction. The purpose of this study was to delineate the radiographic effects of the Cotton osteotomy by controlling for concomitant procedures used for deformity correction. Methods: We retrospectively analyzed 67 patients who underwent a Cotton osteotomy as part of a flatfoot reconstructive procedure. We evaluated 12 radiographic parameters including the articular surface angles of the foot, Meary angle, and a newly defined medial arch sag angle (MASA). Twenty-eight of these patients were matched to a cohort that did not undergo a Cotton osteotomy. Results: In all patients who underwent a Cotton osteotomy, there were statistically significant changes in the articular surface angles and medial arch height (P < .05). No radiographic secondary sag of the medial column was seen at final follow-up. Compared to 28 matched controls, the Cotton osteotomy did not improve Meary angle but provided an additional 6.5 degrees correction of the MASA (P = .002). After reliability testing, the intraclass correlation coefficient was found to be substantial for the MASA compared to Meary angle. Discussion: The data suggest that the MASA was a useful radiographic tool for assessing midfoot collapse in the setting of pes planovalgus. The current study demonstrated the corrective capacity of the Cotton osteotomy on the MASA; at final follow-up, there was no evidence of radiographic instability. This is suggestive that a naviculocuneiform arthrodesis may not be warranted for medial column stabilization in the setting of flatfoot reconstruction. Level of Evidence: Level III, case control study.

Revision Total Ankle Replacement

Overview Introduction The technique for revision total ankle replacement described in this article addresses the subsidence and loosening that occur when an Agility total ankle replacement fails. Step 1: Indications and Contraindications The main indications for revision total ankle arthroplasty include loosening and subsidence of the talar component, with no limit to the extent of subsidence or loss of talar bone stock as neither precludes use of a revision system, particularly when a flat cut on the talus can be made. Step 2: Anterior Incision and Joint Exposure Make the incision employing the prior anterior midline incision, create full-thickness flaps of tissue to diminish the risk of wound dehiscence, and completely expose and debride the joint as this is critical to revising the total ankle replacement correctly. Step 3: Remove the Talar Component and Polyethylene Remove the talar component, which is rarely difficult as it is usually loose. Step 4: Remove the Tibial Component When removing the tibial component, it is critical to preserve as much of the anterior tibial cortex as possible to provide support for the revision tibial component. Step 5: Make the Tibial Bone Cut Tibial cuts can be made proximal or distal to tibial osseous defects. Step 6: Make the Talar Bone Cut It is preferable to use a cutting block for the talus that attaches to the tibial guide. Step 7: Managing Loosening and Cavitary Defects If there is substantial bone loss around the tibia after component removal, consider impaction bone-grafting, as better bone quality makes it is easier to obtain a press fit and allow immediate weight-bearing. Step 8: Place Trial Components Size the tibia and talus and subsequently insert the tibial and talar trials and polyethylene simultaneously. Step 9: Cementing Technique In revision settings, manual cement insertion is important because there is no medullary canal to work around. Results We previously reported the outcomes of revision of failed Agility total ankle replacements (DePuy, Warsaw, Indiana) in forty-one patients. Pitfalls & Challenges

Reproducibility of Computed Tomography to Evaluate Ankle and Hindfoot Fusions

Background: Although plain radiographs have been historically used to evaluate the status of arthrodesis in the foot and ankle, computed tomography (CT) has gained popularity for evaluation of fusion status. The degree of fusion identified on CT scan has been correlated with functional outcome, with an arthrodesis area of 25-50% necessary for clinical success. In the clinical setting, orthopaedic surgeons often evaluate CT scans independently. The purpose of this study was to evaluate the interrater reliability of CT scans to assess the status of hindfoot or ankle fusions among orthopaedic foot and ankle surgeons. Methods: Forty-one CT scans were identified retrospectively from the tertiary referral practices of 4 fellowship-trained orthopaedic foot and ankle surgeons. Inclusion criteria were patients with ankle, subtalar, or tibiotalocalcaneal fusions. Fusions with bulk allograft were excluded. All CT scans were completed at the investigating institution. The primary author (RAC) reviewed all CT scans to ensure the adequacy and completeness of the films. Images were blinded of any patient identifiers. All 4 surgeons individually reviewed the blinded scans and determined whether the arthrodesis site was greater than or less than 50% fused. Interrater reliability was completed via kappa analysis. Results: Based on kappa analysis, there was high interrater reliability in the assessment of subtalar arthrodesis. This was not statistically significant for the evaluation of ankle arthrodesis. Conclusion: The CT scan has become instrumental in determining the adequacy of arthrodesis in the foot and ankle. The present study demonstrates the reliability of orthopaedic surgeons to ascertain the status of subtalar arthrodesis via CT scan. Level of Evidence: Level IV, case series.

The Impact of Nitinol Staples on the Compressive Forces, Contact Area, and Mechanical Properties in Comparison to a Claw Plate and Crossed Screws for the First Tarsometatarsal Arthrodesis

Background. The optimal fixation method for the first tarsometatarsal arthrodesis remains controversial. This study aimed to develop a reproducible first tarsometatarsal testing model to evaluate the biomechanical performance of different reconstruction techniques. Methods. Crossed screws or a claw plate were compared with a single or double shape memory alloy staple configuration in 20 Sawbones models. Constructs were mechanically tested in 4-point bending to 1, 2, and 3 mm of plantar displacement. The joint contact force and area were measured at time zero, and following 1 and 2 mm of bending. Peak load, stiffness, and plantar gapping were determined. Results. Both staple configurations induced a significantly greater contact force and area across the arthrodesis than the crossed screw and claw plate constructs at all measurements. The staple constructs completely recovered their plantar gapping following each test. The claw plate generated the least contact force and area at the joint interface and had significantly greater plantar gapping than all other constructs. The crossed screw constructs were significantly stiffer and had significantly less plantar gapping than the other constructs, but this gapping was not recoverable. Conclusions. Crossed screw fixation provides a rigid arthrodesis with limited compression and contact footprint across the joint. Shape memory alloy staples afford dynamic fixation with sustained compression across the arthrodesis. A rigid polyurethane foam model provides an anatomically relevant comparison for evaluating the interface between different fixation techniques. Clinical Relevance. The dynamic nature of shape memory alloy staples offers the potential to permit early weight bearing and could be a useful adjunctive device to impart compression across an arthrodesis of the first tarsometatarsal joint. Levels of Evidence: Therapeutic, Level V: Bench testing

Evaluation of Nitinol Staples for the Lapidus Arthrodesis in a Reproducible Biomechanical Model.

While the Lapidus procedure is a widely accepted technique for treatment of hallux valgus, the optimal fixation method to maintain joint stability remains controversial. The purpose of this study is to evaluate the biomechanical properties of new shape memory alloy (SMA) staples arranged in different configurations in a repeatable first tarsometatarsal arthrodesis model. Ten sawbones models of the whole foot (n = 5 per group) were reconstructed using a single dorsal staple or two staples in a delta configuration. Each construct was mechanically tested non-destructively in dorsal four-point bending, medial four-point bending, dorsal three-point bending, and plantar cantilever bending with the staples activated at 37°C. The peak load (newton), stiffness (newton per millimeter), and plantar gapping (millimeter) were determined for each test. Pressure sensors were used to measure the contact force and area of the joint footprint in each group. There was a statistically significant increase in peak load in the two staple constructs compared to the single staple constructs for all testing modalities with P values range from 0.016 to 0.000. Stiffness also increased significantly in all tests except dorsal four-point bending. Pressure sensor readings showed a significantly higher contact force at time zero (P = 0.037) and contact area following loading in the two staple constructs (P = 0.045). Both groups completely recovered any plantar gapping following unloading and restored their initial contact footprint. The biomechanical integrity and repeatability of the models was demonstrated with no construct failures due to hardware or model breakdown. SMA staples provide fixation with the ability to dynamically apply and maintain compression across a simulated arthrodesis following a range of loading conditions.

Tendon Transfers for Hallux Varus

Although there are multiple etiologies of hallux varus, it occurs most commonly after the surgical correction of a hallux valgus deformity. While pain with shoe wear is considered to be the primary surgical indication, cosmesis needs to be accounted for as well. For patients with flexible deformities and no evidence of arthrosis at the metatarsophalangeal joint, several soft tissue procedures exist. This technique paper will detail the nature of these procedures that the authors consider to be the most current in application.

Reconstruction of the Tibialis Anterior Tendon With Allograft: A Novel Technique

Rupture of the tibialis anterior tendon is often not clinically recognized. It typically occurs in the atraumatic setting and leads to a steppage gait. For sedentary individuals, nonoperative management may be considered. In more active individuals with stable soft-tissue envelope and a stable neurovascular status, reconstruction of the tendon is a viable option. This technique paper introduces a novel technique that bypasses the need to open the extensor retinaculum and avoids potential wound complications. Levels of Evidence: Diagnostic Level 5. See Instructions for Authors for a complete description of levels of evidence.

Foot Pain in the Child and Adolescent

There are multiple causes of pediatric foot and ankle pain. Although conservative measures are appropriate for initial management, patients with refractory pain should be given consideration for further intervention. This review highlights some of the most common causes of foot and ankle pain in the child, with specific attention to demographics, etiologies, diagnostic workup, and treatment options.

Lyme arthritis of the pediatric ankle.

Lyme arthritis results from acute inflammation caused by the spirochete Borrelia burgdorferi. The number of cases per year has been rising since 2006, with a majority of patients being affected in the northeastern United States. Development of Lyme arthritis is of particular importance to the orthopedic surgeon because Lyme arthritis often presents as an acute episode of joint swelling and tenderness and may be confused with bacterial septic arthritis. Considering the vast difference in treatment management between these 2 pathologies, differentiating between them is of critical importance. Septic arthritis often needs to be addressed surgically, whereas Lyme arthritis can be treated with oral antibiotics alone. Laboratory testing for Lyme disease often results in a delay in diagnosis because many laboratories batch-test Lyme specimens only a few times per week because of increased expense. The authors present a case of Lyme arthritis in the pediatric ankle in an endemic region. No clear algorithm exists to delineate between septic arthritis and Lyme arthritis of the joint. Improved clinical guidelines for the identification and diagnosis of Lyme arthritis of the ankle are important so that appropriate antibiotics can be used and surgery can be avoided.

The Influence of Diabetes Mellitus on Ankle Fracture Treatment: A Review of the National Surgical Quality Improvement Project (NSQIP)

Category: Trauma Introduction/Purpose: Diabetes mellitus is an epidemic affecting millions of individuals in the United States. This presents a challenging clinical problem from a surgical perspective, because of concerns for postoperative complications, including delayed wound healing, infection or compromise of fixation/repair constructs. The goal of this paper was to retrospectively review outcomes data from the American College of Surgeons: National Surgical Quality Improvement Program (ACS-NSQIP) to delineate more clearly the impact that diabetes has on operative treatment of ankle fractures, including bimalleolar and lateral malleolar injuries. Methods: Patients were identified from the 2006-2015 ACS-NSQIP database. Diabetic and non-diabetic cohorts were evaluated to compare demographics, comorbidities, perioperative details and 30-day outcomes. Univariate analysis was performed using chi-squared or Fisher’s exact and Wilcoxon signed-rank tests. A multivariate logistic regression model was created to identify independent risk factors for complications. Odds ratios were computed at the 95% confidence interval. Results: There were a total of 3745 (bimalleolar injuries [1579], lateral malleolar injuries [2166]) patients identified. With regard to treatment of distal fibular or bimalleolar injuries, diabetic patients were more likely to have a longer length of hospital stay (p < 0.05). Based on multivariate analysis, diabetic patients undergoing operative fixation of bimalleolar injuries are at higher risk for superficial incisional surgical site infection (SSI) (OR 3.26; p=0.01), any complication (OR 1.73; p<0.001), myocardial infarction (OR 10.89; p=0.046), and readmission (OR 2.38; p=0.01). In the setting of lateral malleolar fracture operative fixation, diabetic patients were at higher risk for any complication (OR 2.48; p=0.002), return to OR for unexpected complications (OR 5.88; p<0.001), and urinary tract infection (OR 4.72; p=0.03) Conclusion: Based on upon the results of this study, diabetic patients are at higher risk for postoperative complications after ankle fracture fixation, namely infection and re-operation and readmission to the hospital within 30 days after surgery. This information can help clinicians guide patients appropriately prior to surgery.