Scandinavian Total Ankle Replacement: 15-Year Follow-up.

BACKGROUND: Over the past decade, total ankle arthroplasty (TAA) has become a mainstay in the treatment of end-stage ankle arthritis. Currently in its fourth generation, the Scandanavian Total Ankle Replacement (STAR) is the only 3-piece mobile bearing ankle prosthesis available in the United States. Our current study reports implant survivorship at 15 years and patient outcomes for a subset of these survivors available for study. METHODS: Eighty-four TAAs were performed between 1998 and 2000. Metal component survivorship at 15 years was calculated with a Kaplan-Meier curve. Twenty-four (29%) of 84 patients were available for participation with a minimum 15-year follow-up. Any radiographic changes were documented. All additional procedures and complications were recorded. Clinical findings, self-reported performance and pain evaluations, and AOFAS ankle/hindfoot scores were noted. RESULTS: Metal implant survival was 73% at 15 years. Of the 24 patients available for clinical evaluation, 18 of 24 patients (70.7%) had no change in prosthetic alignment from the immediate postoperative radiograph. Only 1 subtalar fusion was required for symptomatic adjacent joint arthritis. Three patients sustained a broken polyethylene component. AOFAS scores improved from an average of 39.6 points preoperatively, to an average of 71.6. More than half (52.4%) of patients with retained implants required an additional surgical procedure; 3 required 2 additional procedures. The average time to subsequent procedure was 10.2 years. CONCLUSION: Our small cohort demonstrated STAR ankles with retention at 9 years were highly likely to survive to 15 years, and patients continued to have significant improvement in pain relief and minimal decrease in function. At 15 years from TAA, metal survivorship was 73%. As with all ankle replacements, supplementary procedures were common. LEVEL OF EVIDENCE: Level IV, case series.

Correction of moderate to severe coronal plane deformity with the STAR ankle prosthesis.

BACKGROUND: Prior studies have demonstrated a correlation between the degree of preoperative coronal plane deformity and failure following ankle replacement. We reviewed all of our patients who underwent ankle replacement utilizing the STAR prosthesis from 2000 to 2009 to evaluate the outcome of those with moderate (10 to 19 degrees) and severe (20 degrees or greater) coronal plane deformity. MATERIALS AND METHODS: Out of 130 consecutive patients, 43 patients had at least 10 degrees of preoperative coronal plane deformity. Twenty-five ankles had 10 to 19 degrees degrees of deformity and 18 ankles had 20 degrees or greater deformity. Average age was 66 years. Average length of followup was 41 (range, 12 to 98) months. RESULTS: Average talar preoperative deformity was 17.9 (range, 10 to 29) degrees, while average initial talar postoperative deformity was 3.5 (range, 0 to 12) degrees. Average final talar postoperative deformity was 4.7 (range, 0 to 14) degrees. Preoperative and final correction of deformity was statistically significant (p < 0.01), but there was no significant difference between initial and final postoperative correction. Overall, recurrence of the preoperative coronal plane deformity occurred in six of 43 patients (14%). All three patients who had deformities over 25 degrees developed recurrences. Correction of the coronal plane deformities was achieved by using intraoperative soft-tissue balancing, including deltoid ligament release in 12 patients and lateral ligament reconstruction in one patient. Deltoid ligament release was found to be necessary for all patients with greater than 18 degrees of varus plane deformity. CONCLUSION: Correction of moderate to severe coronal plane deformity with the STAR prosthesis was achievable with only soft-tissue balancing procedures with predictable results especially for deformities less than 25 degrees.

STAR™ ankle: long-term results.

BACKGROUND: There has been a resurgence of interest in total ankle replacement (TAR) due to improved results with newer prostheses. However, long-term survivorship data has been limited. The STAR™ Ankle prosthesis is the first three-part prosthesis approved for use in the United States. MATERIALS AND METHODS: Eighty-four total ankle replacements were performed in 80 patients using the STAR™ Ankle prosthesis and followed prospectively. Postoperatively, patients were evaluated with the AOFAS score for pain and function, and serial radiographs were evaluated for stability and alignment of the prosthesis. Implant failure, secondary procedures, and complications were recorded. RESULTS: Ninety-one percent of prostheses remain implanted at an average followup of 9.1 years. The probability of implant survival was 96% at 5 years and 90% at 10 years. An average 39-point improvement in the AOFAS ankle-hindfoot score was noted, from a mean of 43 to a mean of 82 points. We noted a statistically significant increase in both average pain and function sub-scores. Postoperative range of motion averaged 4.5 degrees of dorsiflexion and 35 degrees of plantarflexion. Ninety-two percent of the patients were satisfied with their outcome. Ten patients (13%) developed concerning osteolytic lesions. Change in prosthetic alignment and adjacent joint arthritis were similar to previous reports. We report 21 complications, which included 14 additional surgical procedures. CONCLUSION: The first U.S. prospective long-term survivorship data with the STAR™ Ankle prosthesis found it to be an excellent long-term option for the treatment of ankle arthritis.

Prospective controlled trial of STAR total ankle replacement versus ankle fusion: initial results.

BACKGROUND: Mobile-bearing ankle replacements have become popular outside of the United States over the past two decades. The goal of the present study was to perform a prospective evaluation of the safety and efficacy of a mobile-bearing prosthesis to treat end stage ankle arthritis. We report the results of three separate cohorts of patients: a group of Scandanavian Total Ankle Replacement (STAR) patients and a control group of ankle fusion patients (the Pivotal Study Groups) and another group of STAR total ankle patients (Continued Access Group) whose surgery was performed following the completion of enrollment in the Pivotal Study. MATERIALS AND METHODS: The Pivotal Study design was a non-inferiority study using ankle fusion as the control. A non-randomized multi-centered design with concurrent fusion controls was used. We report the initial perioperative findings up to 24 months following surgery. For an individual patient to be considered an overall success, all of the following criteria needed to be met: a) a 40-point improvement in total Buechel-Pappas ankle score, b) no device failures, revisions, or removals, c) radiographic success, and d) no major complications. In the Pivotal Study (9/00 to 12/01), 158 ankle replacement and 66 arthrodesis procedures were performed; in the Continued Access Study (4/02 to 10/06), 448 ankle replacements were performed, of which 416 were at minimum 24 months post-surgery at time of the database closure. RESULTS: Major complications and need for secondary surgical intervention were more common in the Pivotal Study arthroplasty group than the Pivotal Study ankle fusion group. In the Continued Access Group, secondary procedures performed on these arthroplasty patients decreased by half when compared with the Pivotal Arthroplasty Group. When the Pivotal Groups were compared, treatment efficacy was higher for the ankle replacement group due to improvement in functional scores. Pain relief was equivalent between fusion and replacement patients. The hypothesis of non-inferiority of ankle replacement was met for overall patient success. CONCLUSION: By 24 months, ankles treated with STAR ankle replacement (in both the Pivotal and Continued Access Groups) had better function and equivalent pain relief as ankles treated with fusion.

Evaluation and treatment of navicular stress fractures, including nonunions, revision surgery, and persistent pain after treatment.

Despite increased awareness of stress fractures of the tarsal navicular and a heightened index of suspicion by those physicians evaluating sports related foot pain, these injuries remain difficult to diagnose. There is often a considerable delay in the diagnosis because of its subtle and often vague clinical presentation. Accompanying a thorough history and physical, the authors recommend plain radiographs of the foot and ankle, followed by a CT scan to fully characterize any fracture of the navicular and to rule out other etiologies of foot pain. If a CT scan is negative, and a high clinical suspicion persists, an MRI scan is then obtained to rule out a stress reaction. While often successful, non-operative treatment of navicular stress fractures is prolonged and often frustrating to the competitive athlete; surgical intervention for appropriately selected patients can result in full symptom resolution and a return to the desired level of athletic participation.

Keratotic disorders of the plantar skin.

Keratotic lesions on the plantar aspect of the foot develop beneath an osseous prominence and can result in substantial disability. This occurs because, during normal gait, the metatarsal head area is subjected to more prolonged stress than any other area on the plantar aspect of the foot. In the treatment of this disorder, it is imperative to establish the etiology, among many possibilities, and then address the specific pathology accordingly.

The bunionette deformity.

The bunionette deformity results in pain about the lateral and/or the plantar aspect of the fifth metatarsal head. It is important to carefully assess the deformity anatomically in order to select the proper surgical procedure to correct this painful affliction. Knowledge of pathoanatomy and certain surgical procedures can be used to correct the deformity.

Autologous osteochondral grafting for talar cartilage defects.

The purpose of this study was to evaluate the clinical results of Osteochondral Autograft Transfer System (OATS) for the treatment of symptomatic osteochondral defects of the talus using standardized outcome analysis. Nineteen patients with symptomatic osteochondral defect (OCD) of the talus were treated with autologous osteochondral grafting. There were six men and 13 women. The average age was 32 years (range, 18 to 48 years). The average duration of symptoms prior to surgery was 4.2 years (range, three months to 12 years). All patients had failed nonoperative treatment, and 13 (68%) patients had failed prior excision, curettage and/or drilling of the lesion. The average size of the lesion prior to autografting was 12 mm x 10 mm (range, 10 x 5 mm to 20 x 20 mm). Donor plugs were harvested from the trochlear border of the ipsilateral femoral condyle. Ankle exposure was obtained with a medial malleolar osteotomy in 13 patients, arthrotomy in five patients and lateral malleolar osteotomy in one patient. Clinical evaluations were performed for both the recipient ankle and donor knee using the AOFAS Ankle/Hindfoot Scale and Lysholm knee scale, respectively. The average follow-up time was 16 months (range, 12 to 30 months). The average postoperative AOFAS ankle score was 88 (range, 60 to 100). Most patients had occasional mild pain, but excellent function, range of motion, stability and alignment. The average postoperative ankle score for the 13 patients who failed prior surgery was 91 (range, 84 to 100). The average postoperative Lysholm knee score was 97 (range, 87 to 100). Only two patients had mild knee pain. Postoperative radiographs were available for 13 patients. There was no evidence of graft subsidence and all grafts healed. All malleolar osteotomies united. Seventeen (89%) patients said that they would undergo the procedure again. The results of osteochondral autograft transplant for OCD lesions of the talus demonstrate excellent postoperative ankle scores including improvement of pain and function with minimal knee donor site morbidity. Also, our results indicate that this is an effective salvage procedure following failed previous procedures and for patients with longstanding symptoms.