Scandinavian Total Ankle Replacement

Abstract

The purpose of the current prospective study was to determine the midterm results of 68 total ankle replacements with the Scandinavian Total Ankle Replacement (S.T.A.R.) prosthesis. The 65 patients (34 women and 31 men; mean age at surgery, 56.1 years [range, 22-85 years]) were assessed clinically and radiologically after 3.7 years (range, 2.4-6.2 years). Thirty-five patients (54%) were totally pain-free. The overall clinical score was graded as excellent or good in 67 ankles. The American Orthopaedic Foot and Ankle Society hindfoot score improved from 24.7 points (range, 3-44 points) preoperatively to 84.3 points (range, 44-100 points) at followup. Three patients (three ankles, 4.4%) had a ballooning bone lysis on the tibial side. Despite prophylaxis, periarticular hypertrophic bone formation was seen in 43 ankles (63%; 42 patients), associated with a decrease of dorsiflexion and plantar flexion. Nine ankles (13%; nine patients) had revision surgery because of problems with the components and 14 ankles (21%; 14 patients) had secondary or additional operations. All revision or secondary surgeries were successful, and no ankle had to be converted to an ankle arthrodesis. The early experience with the S.T.A.R. ankle implant is encouraging, although we have encountered more complications and potential problems than previously reported.Although numerous studies have shown encouraging short-term results of total ankle arthroplasty, 6,13,17,21 medium-term and long-term results have revealed considerable complications, including ankle pain, painful malleolar impingement, tibial component loosening, and talar component subsidence. 2,7,18,20,22,23,25 The length of followup was a major factor in relation to patient satisfaction, with patients with longer followup generally having declining degrees of satisfaction. The major factors implicated in loosening were highly constrained designs and cement fixation. 4,9 More recent approaches to total ankle replacement have emerged to permit semiconstrained to nonconstrained motion, and to rely on bone ingrowth for implant stability. Among others, the cementless, three-component S.T.A.R. (LINK S.T.A.R. Scandinavian Total Ankle Replacement, Waldemar Link, Hamburg, Germany) prosthesis has become popular. For the cementless S.T.A.R. prosthesis, to our knowledge, only two studies have provided outcomes in the peer reviewed literature. Kofoed and Danborg 11 reported very encouraging results in 31 in patients with osteoarthritis (OA), who were followed up for 3.5 years (range, 1-8 years). In this series, there was one revision done for malalignment. All patients were reported to be improved clinically as a result of the operation, and none had evidence of component loosening or subsidence. In seven ankles treated in patients with rheumatoid arthritis (RA), Wood et al 24 reported good function and range of motion (ROM) for maximal dorsiflexion to maximal plantar flexion of 30°after 5.4 years (range, 5-6 years). None of the seven ankles had any progressive lucency.The purpose of the curren...

Intermediate Term Outcome of the Agility™ Total Ankle Arthroplasty

“…As a result, a second generation of ankle replacement designs emerged. 4,5,9,34,35,43,45,55,56,57,58 Published results for second generation total ankle arthroplasty designs are better than the first generation results. 10,14,17,28,35 As an aside it should be noted that with better techniques of internal fixation, ankle fusion results have also improved.…”

Ligament Balancing for Total Ankle Arthroplasty: An in vitro Evaluation of the Elongation of the Hind- and Midfoot Ligaments

“…6 Deformities of the hindfoot, excluding the ankle joint, have been corrected by osteotomies or arthrodesis. 11,47 To improve the range of motion during total ankle arthroplasty an achilles tendon lengthening or a gastrocnemius recession was added to many procedure. 11,47 Table 1 gives an overview of the ligaments that could contribute to balancing the ankle ligament or increase range of motion during total ankle replacement.…”

Scandinavian Total Ankle Replacement: The Surgical Technique

“…1,7,10,[15][16][17][18][19][20][21][22] Generally, it has been found to give very satisfactory results. We shall continue to follow our cases long-term.…”