Eric W. Tan

Early Complications and Secondary Procedures in Transfibular Total Ankle Replacement.

Background: A new transfibular total ankle arthroplasty (TAA) system has not been assessed for potential early complications. Methods: We retrospectively assessed prospectively collected data on the initial cohort of patients undergoing TAA with this implant. We evaluated visual analog scale (VAS) pain and function, range of motion, and early radiographic outcomes. Results: Twenty consecutive TAAs (19 patients) were treated with the implant from January 2013 through June 2014. Average patient age was 63.7 (range, 41-80) years, with an average follow-up of 18 (range, 12-27) months. No fibular nonunion or implant failure was found at 12 months postoperatively. One patient had asymptomatic mild tibial lucency. Four of 20 TAAs underwent additional surgery for anterior impingement (1 ankle), deep infection and symptomatic fibular hardware (1 ankle), and symptomatic fibular hardware (2 ankles). Conclusion: Of 20 ankles treated with a new transfibular arthroplasty system, no fibular nonunion, delayed union, or implant failure was noted at 12 months postoperatively. Two complications were resolved with secondary treatment, and 2 other ankles underwent secondary surgery for symptomatic fibular hardware with good outcome. The findings suggest that this total ankle system is safe and effective at short-term follow-up. Level of Evidence: Level IV, retrospective case series.

Identifying the learning curve for total ankle replacement using a mobile bearing prosthesis

BACKGROUND Total ankle arthroplasty remains a technically demanding surgery highly influenced by the operator experience. However, no consensus exists regarding the ideal number of cases that need to be performed before a surgeon is considered proficient. The aim of this study was to identify the learning curve of a specific replacement system with regards to intraoperative and postoperative outcomes. METHODS The first 31 patients undergoing total ankle arthroplasty were examined. No additional procedures were performed at the time of the TAA. Intraoperative characteristics, postoperative complications, as well as clinical and radiologic outcomes were assessed with 24-month follow-up. Learning curves, examining the relationship between surgeon experience and patient outcomes, were determined using the Moving Average Method. RESULTS The operatory time, and the risk of intraoperative fractures decreased with increasing surgeon experience with the learning curve stabilizing after the 14th and 24th patient, respectively. Furthermore, there appeared to be a learning curve associated with most of the important clinical and radiological outcomes. The number of patients required to stabilize the learning curve for the VAS, ROM, and AOFAS was 11, 14 and 28, respectively. Radiographically, there appeared to be a learning curve of 22 patients required to stabilize the tibio-talar ratio. There was no learning curve associated with the SF-12 PCS and MCS as well as the α-, β-, and γ-angle. CONCLUSION This study demonstrates that a surgical learning curve does indeed exist when performing TAA. Most of the operative variables as well as clinical and radiological outcomes stabilize after a surgeon has performed 28 cases.

Posterior Talar Shifting in Mobile-Bearing Total Ankle Replacement

Background: End-stage ankle osteoarthritis frequently involves multiplanar malalignment in both the coronal and the sagittal planes. Sagittal malalignment often includes anterior translation of the talus relative to the tibia. Restoration of the correct tibial and talar alignment is essential for the long-term survival of total ankle replacement. Methods: This study includes 66 consecutive patients who underwent total ankle arthroplasty with the Hintegra prosthesis from May 2011 to April 2014. There were 28 females (42.4%) and 38 males (57.6%) with a mean age of about 57 years (25-82 years). Patients were clinically and radiologically assessed preoperatively and at 2, 6, and 12 months postoperatively. Results: At 12 months postoperatively, there was a statistically significant increase in American Orthopaedic Foot & Ankle Society scores from 31.9 to 72.3. Range of motion significantly increased from 9.5 to 25.4 degrees. In addition, there was a statistically significant decrease in visual analog scale (VAS) pain score from 8.9 to 2.2. Furthermore, there was a significant increase in the Tibio-Talar ratio from 2 to 6 months postoperatively (34.6%-37.2%). Conclusions: This study demonstrated significant improvements in clinical and radiologic outcomes after Hintegra total ankle arthroplasty. Significant movement of the talus occurs within the first 6 months postoperatively. This may be the result of rebalancing of muscle and ligament forces after surgery. Level of Evidence: Level IV, case series.

Safe Zone for Neural Structures in Medial Displacement Calcaneal Osteotomy A Cadaveric and Radiographic Investigation

Background: We aimed to define reference lines on standard lateral ankle radiographs that could be used intraoperatively to minimize iatrogenic nerve injury risk in medial displacement calcaneal osteotomy. Methods: Forty cadaveric specimens were used. In 20 specimens, the sural, medial plantar (MP), and lateral plantar (LP) nerves were sutured to radiopaque wire, and a lateral ankle radiograph was obtained. On the radiograph, a line was drawn from the posterior superior apex of the calcaneal tuberosity to the origin of the plantar fascia and labeled as the “landmark line.” A parallel line was drawn 2 mm posterior to the most posterior nerve, and the area between these lines was defined as the safe zone. In 20 additional specimens, an osteotomy was performed 1 cm anterior to the landmark line using a percutaneous or open technique. Dissection was performed to assess for laceration of the sural, MP, LP, medial calcaneal (MC), or lateral calcaneal (LC) nerves. Results: The safe zone was determined to be within the area 11.2 ± 2.7 mm anterior to the landmark line. After open osteotomy, lacerations were found in 3 of 10 MC nerves and 3 of 10 LC nerves. After percutaneous osteotomy, lacerations were found in 2 of 10 MC nerves and 1 of 10 LC nerves. No lacerations of the sural, MP, or LP nerves were found with either osteotomy. Conclusions: The safe zone extended 11.2 ± 2.7 mm anterior to the described landmark line. The MC and LC nerves were always at risk during medial displacement calcaneal osteotomy. Clinical Relevance: Nerve injury to both major and minor sensory nerves is likely underrecognized as a source of morbidity after calcaneal osteotomy. The current study provides a ready intraoperative guideline for minimizing this risk.

Early Weightbearing After Operatively Treated Ankle Fractures: A Biomechanical Analysis.

Background: No consensus exists regarding the timing of weightbearing after surgical fixation of unstable traumatic ankle fractures. We evaluated fracture displacement and timing of displacement with simulated early weightbearing in a cadaveric model. Methods: Twenty-four fresh-frozen lower extremities were assigned to Group 1, bimalleolar ankle fracture (n=6); Group 2, trimalleolar ankle fracture with unfixed small posterior malleolar fracture (n=9); or Group 3, trimalleolar ankle fracture with fixed large posterior malleolar fracture (n=9) and tested with axial compressive load at 3 Hz from 0 to 1000 N for 250 000 cycles to simulate 5 weeks of full weightbearing. Displacement was measured by differential variable reluctance transducer. Results: The average motion at all fracture sites in all groups was significantly less than 1 mm (P < .05). Group 1 displacement of the lateral and medial malleolus fracture was 0.1±0.1 mm and 0.4±0.4 mm, respectively. Group 2 displacement of the lateral, medial, and posterior malleolar fracture was 0.6±0.4 mm, 0.5±0.4 mm, and 0.5±0.6 mm, respectively. Group 3 displacement of the lateral, medial, and posterior malleolar fracture was 0.1±0.1 mm, 0.5±0.7 mm, and 0.5±0.4 mm, respectively. The majority of displacement (64.0% to 92.3%) occurred in the first 50 000 cycles. There was no correlation between fracture displacement and bone mineral density. Conclusion: No significant fracture displacement, no hardware failure, and no new fractures occurred in a cadaveric model of early weightbearing in unstable ankle fracture after open reduction and internal fixation. Clinical Relevance: This study supports further investigation of early weightbearing postoperative protocols after fixation of unstable ankle fractures.

Effect of Insurance on Rates of Total Ankle Arthroplasty Versus Arthrodesis for Tibiotalar Osteoarthritis

Background: Several studies have examined the effect of insurance on the management of various orthopedic conditions. The purpose of our study was to assess the effect of insurance and other demographic factors on the operative management of tibiotalar osteoarthritis. Methods: The National Inpatient Sample (NIS) database was used to identify patients who underwent a total ankle arthroplasty (TAA) or tibiotalar arthrodesis (TTA) for tibiotalar osteoarthritis. Insurance status was identified for each patient, and the proportions of each insurance type were computed for each operative modality. A multivariate analysis was performed to account for confounding variables to isolate the effect of insurance type on operative treatment. Results: From 2007 to 2012, a total of 10 010 patients (35.6%) were identified who underwent a total ankle replacement (TAR) procedure and 18 094 patients (64.4%%) who underwent TTA for tibiotalar osteoarthritis. Patients receiving a TAR were older (65.8 vs 64.2, P < .001), more likely to be female (54% vs 51%, P < .001), and had fewer comorbidities (4.2 vs 4.5, P < .001) than patients who underwent a TTA. After controlling for baseline differences, patients with Medicare (odds ratio [OR] 3.00, P < .001), and private insurance (OR 3.19, P < .001) were approximately 3 times more likely to undergo TAR than patients with Medicaid. Conclusions: Patients with tibiotalar osteoarthritis were more likely to receive a TAR procedure if they had Medicare or private insurance compared with patients who had Medicaid. Further research should be done to better understand the drivers of this phenomenon if equitable care is to be achieved. Level of Evidence: Level II, prognostic study.

Cartilage Mesh Augmentation Technique for Treatment of Osteochondral Lesions of the Talus

Osteochondral lesions of the talus are a common cause of ankle pain and disability. After failure of nonsurgical management, surgical options tailored to specific characteristics of the lesion are considered. Surgical interventions include marrow-stimulation techniques, such as debridement and microfracture, osteochondral autograft transfer, osteochondral allograft transfer, autologous chondrocyte implantation, and particulated juvenile cartilage allograft transplantation. Cartilage mesh allograft, a viable whole-tissue cartilage allograft, is a new product designed to augment marrow-stimulation procedures. This article will provide an overview of current management options available for the treatment of osteochondral lesions of the talus and focus on the emerging use of cartilage mesh allograft to enhance traditional surgical techniques. Level of Evidence: Diagnostic Level 4. See Instructions for Authors for a complete description of levels of evidence.

☆Diagnostic and therapeutic injections of the foot and ankle—An overview

Foot and ankle injections are useful diagnostic and therapeutic tools, particularly when the pain etiology is uncertain. A variety of foot and ankle injuries and pathologies, including degenerative joint disease, plantar fasciitis and different tendinopathies are amenable to injections. Understanding the foot and ankle anatomical landmarks, a thorough physical exam and knowledge of the different injection techniques is key for a successful approach to different pathologies. The objective of this study is to review the use of foot and ankle injections in the orthopaedic literature, present the readers with the senior authors experience and provide a comprehensive clinical guideline to the most common foot and ankle diagnostic and therapeutic injections.

Impact of Computed Tomography on Operative Planning for Ankle Fractures Involving the Posterior Malleolus

Background: The purpose of this study was to (1) Determine the effect of computed tomography (CT) on identification of fractures involving the posterior malleolus, (2) determine its effect on operative indications, and (3) determine its effect on the overall operative plan. Methods: Patients with ankle fractures involving the posterior malleolus were identified. Only injuries with complete preoperative plain radiographs and a CT scan were included. Spiral tibia fractures and pilon variants were excluded. The plain radiographs were deidentified, randomized, and presented to 3 orthopedic surgeons. They were asked 3 questions: (1) Is this fracture simple or complex? (2) Does the injury require direct visualization and reduction? and (3) How would you position the patient and approach the fracture? The same process was repeated for the CT scans. A total of 376 posterior malleolus injuries were identified and 25 met the inclusion criteria. Results: A complex fracture pattern was identified on 44% of plain radiographs and 56% of CT scans. The surgeons chose to operate in 84% of cases based on plain radiographs and 92% of cases based on CT scan. The observers changed their operative approach or positioning 44% of the time after reviewing CT images. The interobserver and intraobserver correlation coefficients were moderate. Conclusion: The use of CT scan changed operative positioning and approach in 44% of cases. There was no significant change in characterization or operative indications when comparing plain radiographs to CT scan. CT scan may be a valuable tool in the management of ankle fractures involving the posterior malleolus. Level of Evidence: Diagnostic Level III, comparative series.

Dual Semitendinosus Allograft Reconstruction of Large Achilles Tendon Defects

Patients with chronic midsubstance Achilles tendinopathy who do not respond to nonoperative management often require surgical intervention. Debridement of the diseased and dysfunctional tendon may result in a gap >5 cm. A number of previously described techniques to bridge the defect include V-Y lengthening, turndown procedures, local tendon transfers, synthetic grafts, and hamstring autograft and allograft. This article describes a novel technique using 2 semitendinosus allografts to reconstruct Achilles tendinopathy with large defects. There are 2 options for distal fixation depending upon the residual amount of Achilles tendon that remains distally on the heel. This technique offers another option for the surgeon in the face of a difficult reconstructive procedure. Early outcomes have been excellent. Level of Evidence: Diagnostic Level 5. See Instructions for Authors for a complete description of levels of evidence.