Description
Introduction
Medial sliding calcaneal osteotomy (MDCO), lateral lengthening calcaneal osteotomy (LLCOT), subtalar arthroereisis or a double calcaneal osteotomy are established procedures in correction of flexible adult acquired flatfoot deformity (AAFD). All of these have different advantages and potential complications. MDCO is insufficient in case of severe malalignment ^1. After LLCOT and double osteotomy, the role of secondary osteoarthritis of the calcaneocuboidal (cc) joints remains unclear ^2. Arthroereisis was used for pediatric flatfoot reconstruction ^3. In adult flatfoot reconstruction the role of arthroereisis remains unclear. The purpose of this study was a comparative analysis of the correction potential, pedobarographic analysis and intraarticular cc-joint pressure after MDCO, LLCOT, double calcaneal osteotomy and MDCO with additional subtalar arthroereisis.
Methods:
30 fresh frozen specimens (mid-tibia to toe-tip) were inserted in a stand simulation device. An axial load of 300 N was used. Most stabilizing tendons were loaded adapted to an established protocol ^4 : Tibialis anterior 40 N, tibialis posterior 40 N, peroneal tendons 44 N and Achilles tendon 300 N. All specimen were tested in a native state. Testing included radiological analysis, pedobarography and intraarticular cc-joint pressure. Afterwards, a senior surgeon (SE) performed MDCO, LLCOT and double calcaneal osteotomy in 10 specimens, respectively. The testing procedure was repeated. In 10 specimen following MDCO an additional subtalar arthroereisis was inserted and the testing repeated. MDCO was done with 8mm sliding. LLCOT was performed as Hintermann-osteotomy with 6,8- and 10-mm wedge sizes.
Results
After all procedures radiologic measurements (lateral talometatarsal angle, dorsoplantar talometatarsal angle and talo-navicular angle) changed significantly (p<0,05). MDCO with an additive subtalar arthroereisis, LLCOT > 8 mm wedge and double calcaneal osteotomy were superior in terms of correction potential (p<0,05). Forefoot supinatus was seen after all procedures (p<0,05). There was an increase of plantar peak pressure of the lateral midfoot after all procedures (<0,05). Intraarticular CC-joint pressure decreased after MDCO and increased after an additive subtalar arthroereisis, However, these changes were not significant (p>05). After LLCOT and double calcaneal osteotomy a significant increase of the intraarticular cc-joint pressure was noticed (p<0,05). A significant difference of the CC-joint pressure was seen between 6 mm wedge size and bigger wedge sizes (p<0,05).
Conclusion:
All treatment options for the correction of flexible AAFD led to an increase in forefoot supinatus and increased plantar pressure of the lateral midfoot. LLCOT > 8 mm wedge, calcaneal double osteotomy and MDCO with an additive arthroereises got the most corrective potential. However, LLCOT led to increased pressure in the CC joint, especially with increasing wedge sizes (>6mm). Considering correction potential, pedobarographic analysis and intraarticular CC-joint pressure MDCO with an additive subtalar arthroereisis seems to have the most beneficial characteristics.
