Short Term Clinical and Radiographic Results of the Salto Mobile Version Ankle Prosthesis Dong Dong Wan, MD; Dong woo Shim, MD; Yoo Jung Park, MD; Yeokgu Hwang, MD; Jin Woo Lee, MD, PhD Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Korea
Disclosure NO CONFLICT TO DISCLOSE Short Term Clinical and Radiographic Results of the Salto Mobile Version Ankle Prosthesis Dong Dong Wan, MD Dong woo Shim, MD Yoo Jung Park, MD Yeokgu Hwang, MD Jin Woo Lee, MD, PhD Our disclosures are in the final AOFAS Mobile App. We have no potential conflicts with this presentation.
Short Term Clinical and Radiographic Results of the Salto Mobile Version Ankle Prosthesis Main treatment for advanced ankle arthritis is limited to TAA and arthrodesis The advantages of TAA vs arthrodesis maintains joint ROM restores more normal kinematics better functional recovery avoids adjacent joints degeneration The Salto (mobile-bearing) implant is still regarded as first-line prosthesis for arthritic patients at present time
Purpose of the research The clinical outcomes of Salto mobile bearing prosthesis were promising All of these reports are limited to Europe Research on TAA are more meaningful in Asian patients (ie. sitting with lotus position, walking on mountain road)
Patients & Methods From January 2012 ~ October 2014 62 severe arthritic patients underwent unilateral Salto TAA by two senior surgeons (JWL & WJC) Postoperative follow-up at 1 month, 3 months, 6months, 1y & annually Follow-up included medical records review, VAS pain scores, AOFAS & AOS (pain & disability) scores, ROM, radiograph Endpoints of the follow-up included implant removal and conversion to arthrodesis
Patients & Methods Radiographic measurements (pre & post operation) tibial angle (TA): a varus/valgus tolera nce range of 4 talar angle (TAL) tibial slope (TS): 5 ± 5 degrees (optim al anatomic design angle 7 ) Talocalcaneal angle (TCA):component migration was defined as a change greater than 5 Distributive area of osteolysis
Clinical outcomes Results Preop Postop P-value VAS 7.0 ± 1.7 2.5 ± 2.2 <0.001 AOFAS 48.8 ± 16.9 80.1 ± 15.0 <0.001 AOS pain 53.5 ± 17.5 17.0 ± 15.5 <0.001 AOS disability 60.8 ± 15.4 28.7 ± 25.5 <0.001 ROM 33.5 ± 16.7 40.5 ± 15.7 0.003 ROM (DF) 9.8 ± 7.8 14.7 ± 7.6 <0.001 ROM (PF) 23.7 ± 10.8 25.8 ± 9.7 0.211
Clinical outcomes The survival rate with any reoperation as the endpoint was 88.7% (95% CI, 80.4% 97.1%). Results Survival rate (%) 100.00% 80.00% 60.00% 40.00% Survival curves (Kaplan-Meier) Failure = reoperation for any reason 20.00% 0.00% Follow-up (months)
Radiologic outcomes Results Preop Postop (6ws) Last f/u P-value (6w vs last) Tibial angle (TA, ) 87.3 ± 3.8 88.4 ± 1.1 88.3 ± 0.2 0.608 Talar angle (TAL, ) 83.7 ± 8.3 88.1 ± 1.2 88.0 ± 1.4 0.150 Tibial slope (TS, ) 14.0 ± 4.5 8.4 ± 2.2 8.2 ± 2.1 0.223 Talocalcaneal angle (TCA, ) N/A 7.4 ± 4.0 7.9 ± 4.0 0.170
Results Radiologic outcomes Distributive zones and frequency of radiolucent area in 28 patients with lucent area Distributive zones and frequency of osteolysis in 28 patients with osteolysis 30 25 25 20 20 Frequency 15 10 AP view (n = 75) Lateral view (n = 18) Frequency 15 10 AP view (n = 63) Lateral view (n = 81) 5 5 0 1 2 3 4 5 6 7 8 9 10 Distributive zones of radiolucent area 0 1 2 3 4 5 6 7 8 9 10 fibula Distributive zones of osteolysis In 28 patients, a radiolucent area appeared mainly around the tibial keel and tray due to stress shielding. Osteolysis was found in 28 patients postoperatively. The distributive zones were around the tibial keel and tray. In addition, two osteolytic lesions were located at the fibula.
Discussion Our short term clinical and radiographic results of Salto prostheses are pro mising with the survival rate of 95.2% 3 osteolytic cysts resulted in prosthetic failure in our cases A CT scan is useful to make sure the precise location and size of the osteol ytic cyst Large size and progressive cyst maybe need surgical intervention Longer follow-up is necessary for this implant
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