Medial displacement calcaneal osteotomy: Loss of correction with varying drilling techniques

Introduction: Joint preserving surgery for flatfoot reconstruction utilizes correction of bony malalignment and medial soft tissue reconstruction. A medial displacement calcaneal osteotomy (MDCO) can be an essential adjunct to deformity correction and good patient outcomes. Our cadaveric study compares three different surgical techniques utilizing two cannulated screws to best maintain medial translation of the calcaneal osteotomies. Materials and methods: Fifteen above knee fresh-frozen, matched pair cadaveric specimens (30 limbs) were randomized equally to three groups. MDCO were performed on all specimens, followed by manual 10 mm translation. The groups consisted of a “simultaneous drilling,” “staggered drilling,” and a control group, which involved simultaneous drilling of only the near cortex. Following screw fixation, the calcaneal tuberosity was manually translated in a lateral direction. The loss of correction was measured in millimeters. Results: The “simultaneous” drilling group experienced the greatest mean loss of correction at 2.6 mm (range 1.37–3.48 mm). The “staggered” group showed an average loss of 1.16 mm (range 0.36–2.67 mm). The control group demonstrated the greatest maintenance of correction with a mean loss of 0.036 mm (range 0.01–0.06 mm). Conclusions: MDCO realigns the hindfoot adding support to the medial soft tissue reconstruction during flatfoot correction. Loss of initial correction may result in residual deformity and poor long-term outcomes. Our study demonstrates that simultaneous drilling of only the tuberosity near cortex prior to screw fixation was the best at maintaining osteotomy correction. Level of evidence: : Level V, Cadaveric stud

Mid Term Followup of Patient Reported Outcomes in Patients <50 years with a Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: End stage arthritis is a debilitating condition that significantly affects patients’ quality of life. Ankle arthritis differs from arthritis of the hip and knee in that ankle arthritis is often posttraumatic in nature and affects a younger patient population. Historically, younger age was a contraindication to total ankle arthroplasty (TAA) and ankle arthrodesis was the mainstay of treatment. Advances in TAA implant design and revision implants has expanded indications and increased usage of TAA. Despite this, many surgeons remain hesitant due to the lack of long term data on patient outcomes and survivorship in these patients. The purpose of our study was to evaluate patient reported outcome measures and survivorship after primary TAA in patients < 50 years of age at the time of surgery. Methods: A retrospective chart review was conducted of patients < 50 years of age who underwent primary TAA at a single institution from 2010-2020. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow up of 5 years. Patient reported outcome (PRO) measures collected included FADI, VAS, SMFA SF-36, AOFAS hindfoot scores, and FAOS scores. Outcome measures were evaluated preoperative, 1 year postoperative, and at final clinical follow up. Paired t-tests were performed to compare individual patients’ changes in PRO from preoperative to postoperative timepoints. Multiple comparisons correction was performed using the Bonferroni method. Implant survivorship was evaluated based on need for revision of either the tibial or talar component. Results: A total of 59 patients were included in the study. The average age at time of surgery was 43.2 years. All patients had a minimum follow up of 5 years with a mean follow up time of 8.8 years. Mean FADI improved from 53.3 (sd:14.1) preoperatively to 16.1 (sd:11.4) (p < 0.001) at 1-year postoperatively. Mean VAS and SMFA also improved from preoperative to 1-year postoperative timepoints [VAS: 68.2 (sd:27.0) to 10.3(sd:13.1) (p < 0.001); SMFA: 36.1 (sd:12.2) to 14.8 (sd:13.7) (p < 0.001)]. A total of 5 patients required revision of components during the follow up period. Three patients required complete revision of both tibial and talar components, 2 due to aseptic loosening and 1 due to deep infection requiring explant of components. Conclusion: Patients < 50 years undergoing TAA for end stage ankle arthritis have improved patients reported outcomes greater than 5 years after surgery. Despite the increased demands of the younger population, survivorship of total ankle implants in our study was 85% at a mean of 8.8 years postoperative. We believe that TAA is a safe and reliable option for young patients with high patient satisfaction at mid term follow up

Early to Mid-Term Follow-up of Total Ankle Arthroplasty in Patients <35 Years

Category: Ankle Arthritis; Ankle Introduction/Purpose: Younger age remains at the forefront of discussion when deciding between total ankle arthroplasty (TAA) and the ankle arthrodesis (AA) for treatment of end stage ankle arthritis. Unlike in the hip and knee, ankle arthritis is typically post-traumatic and presents at a much younger patient age. With the goal of preserving ankle motion, improving function and limiting adjacent joint degeneration, TAA has been shown to be safe and effective in patients < 55 years of age. However, it is not uncommon for debilitating ankle arthritis to occur in individuals within their fourth or even third decade of life resulting in significant patient comorbidity. The purpose of our study was to evaluate patient reported outcome measures and survivorship after primary TAA in patients < 35 years old. Methods: A retrospective chart review was conducted of patients < 35 years old who underwent primary TAA at a single institution from 2007-2020. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow up of 2 years. Patient reported outcome measures collected included VAS, SMFA dysfunction index, SF-36 and AOFAS hindfoot scores. Outcome measures were evaluated preoperative, 1 year postoperative, and at final follow up. Paired t-tests were performed to compare individual patients’ changes in PRO from preoperative to postoperative timepoints. Implant survivorship was evaluated as well as complications related to the index procedure. Implant survivorship based on need for complete revision of either the tibial or talar component Results: Twelve patients were included in the study. Average age at surgery was 28.5 years. Mean follow-up was 7.2 years. Mean VAS improved from 53.8 preoperatively to 14.7 (p= 0.152) at 1-year and 12.5 (p= 0.045) at final follow up, respectively. Mean SMFA improved from 40.0 preoperatively to 27.1 (p= 0.018) at 1-year and 24.0 (p= 0.006) at final follow up, respectively. SF-36 and AOFAS hindfoot scores also improved at 1 year and final follow-up compared to preoperative values [SF-36: 45.3 to 60.2 (p=0.06) and 67.0 (p=0.016); AOFAS: 40.6 to 70 (p= 0.08) and 68.9 (p=0.068)]. One patient required talar component revision due to aseptic loosening. One patient required subsequent removal of heterotopic bone due to impingement. No patients developed infection requiring surgical intervention. Conclusion: The onset of ankle arthritis typically occurs at a much younger age compared with that of the hip and knee and has a detrimental impact on patient quality of life. Despite a young age and increased activity demands, our results demonstrated that patients < 35 with end-stage ankle arthritis undergoing TAA demonstrated improved patient-reported outcomes greater than 2 years after surgery. Survivorship of TAA in our study was 91.7% at a mean follow-up of 7.2 years. We believe that TAA is a safe, effective and durable option for very young patients with high patient satisfaction at early to mid-term follow up

Ballooning Periprosthetic Osteolysis Related to Crystalline Arthropathies Following Total Ankle Arthroplasty: A Case Series

Category: Ankle Arthritis; Basic Sciences/Biologics Introduction/Purpose: From 2009-2019, there has been a 120% increase in the incidence of total ankle arthroplasty (TAA) in the United States. With the rise in primary TAA, future increases in revision TAA cases is anticipated. Aseptic loosening with periprosthetic osteolysis continues to account for a significant number of revisions. While several factors may contribute to the pathophysiology of osteolysis, an underlying inflammatory response surrounding TAA implants may play a primary role. It is well known that monosodium urate (gout) and calcium-pyrophosphate (pseudo-gout) crystals evoke a highly inflammatory response and may involve the foot and ankle joints. However, the effect of these conditions following TAA has not yet been reported. We present a small case series of patients with ballooning osteolysis following TAA with confirmed crystalline arthropathy. Methods: This is a retrospective study from a single academic institution looking at patients who underwent TAA revision surgery for periprosthetic osteolysis and concern for aseptic loosening. Revision surgeries were performed by three orthopedic foot and ankle fellowship trained surgeons. Case characteristics, including pre-operative imaging, clinical presentations, intra-operative findings and surgical treatments performed were analyzed and presented in this small case series. Results: We report 5 patients whom underwent revision surgery for ballooning periprosthetic osteolysis following TAA. Intra- operative pathology samples from periprosthetic cysts returned positive for monosodium urate (MSU) or calcium pyrophosphate (CPP) crystalline deposition (1 MSU and 4 CPP) in all 5 patients. Final intra-operative cultures were all negative for infection. Upon gross intra-operative inspection, all polyethylene liners were considered to be normal without abnormal wear characteristics. Periprosthetic cysts were isolated to the tibial component in 2 patients and involved both the tibial and talar components in 3 patients. Staged TAA revision was performed in 2 patients. Bone cyst curettage, bone grafting and polyethylene liner exchange was performed in 3 patients. Conclusion: Periprosthetic osteolysis is a known complication following TAA and often leads to implant loosening, functional disability and subsequent revision surgery. An objective strategy for management of this condition has not been agreed upon amongst orthopedic foot and ankle surgeons, as uncertainty remains surrounding the pathophysiology of osteolysis in TAA. To our knowledge, we are the first to describe a small case series of patients with crystalline arthropathy as a potential cause for periprosthetic osteolysis following TAA. Future prospective studies are warranted to better elucidate this potential cause of TAA failure