[1] Prince Sultan Mil Med City, POB 13225-6604, Riyadh 12233, Saudi Arabia
[2] Nasser Inst Res & Treatment, Dept Orthoped, Nile Corniche St, Cairo 1351, Egypt
[3] Taibah Univ, Coll Med, Orthopaed Dept, POB 30001, Medina 42353, Saudi Arabia
[4] Kantonsspital Winterthur, Head Foot & Ankle Unit, Orthopaed & Trauma Dept, CH-8401 Winterthur, Switzerland
[5] Univ La Laguna, Head Foot & Ankle Unit, Orthopaed Dept, Tenerife 38200, Spain
[6] Univ Utah, Dept Orthopaed, 590 Wakara Way, Salt Lake City, UT 84108 USA
[7] Schmerzklin Basel, Orthopaed Dept, Swiss Ortho Ctr, Swiss Med Network, Hirschgasslein 15, CH-4010 Basel, Switzerland