Ki Hyuk Sung, MD

1. Amount of correction after calcaneal lengthening for planovalgus foot deformity in patients with cerebral palsy Ki Hyuk Sung, MD Seoul National University Bundang Hospital

2. Introduction • Planovalgus foot deformity is common in patients with cerebral palsy • A complex 3-D malalignment • hindfoot valgus, plantar flexed talus • midfoot planus and pronation • relatively short lateral column • forefoot abduction and supination

3. Introduction • Medial callosities • Hallux valgus • Shoe wear • Pain • Gait disturbance due to lever arm dysfunction

4. Introduction • Surgical options • medial displacement osteotomy of calcaneus • subtalar extra-articular arthrodesis • lengthening of the lateral column • triple arthrodesis • Calcaneal lengthening osteotomy • most commonly used to correct the deformity and not sacrifice joint motion in patients with CP

5. Introduction • Additional procedures, such as, medial soft tissue procedure, medial bony procedure, or triple arthrodesis could be performed concomitantly with calcaneal lengthening depending on severity of deformity. • However, there has been no guideline to determine the necessity of these procedures

6. Purpose of the study • To investigate the amount of correction after calcaneal lengthening for the treatment of planovalgus foot deformity in patients with CP • To guide a surgical indication in terms of the severity of the foot deformity

7. Materials and Methods • Retrospective design • Inclusion • patients with cerebral palsy who underwent calcaneal lengthening for planovalgus deformity between 2003 and 2011 • patients who had preop and postop weight bearing AP and lateral foot radiographs

8. Materials and Methods • Exclusion • patients who had concomitant medial column procedures with calcaneal lengthening • patients with a history of previous foot surgery • patients with inadequate foot radiographs for measurement

9. Radiographic measurement • Lateral foot weight bearing radiograph • Calcaneal pitch angle • Lateral talocalcaneal angle • Lateral talus-first metatarsal angle • Naviculocuboid overlap • Relative calcaneal length • Calcaneocuboid subluxation • Anteroposterior foot weight bearing radiograph • Anteroposterior talus-first metatarsal angle

10. Calcaneal pitch angle

11. Lateral talocalcaneal angle

12. Lateral talus-first metatarsal angle

13. Naviculocuboid overlap (B/A)

14. Relative calcaneal length (a/b)

15. Calcaneocuboid subluxation

16. AP talus-first metatarsal angle

17. Operative procedure

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19. Corrected group • a group of patients whose radiographic indices improved beyond the value of normal alignment after calcaneal lengthening • Under-corrected group • a group of patients whose radiographic indices did not reach the value of normal alignment

20. Reliability of radiographic measurement • Inter-observer reliability (3 observer) • 36 radiographs • ICC (intraclass correlation coefficient) & 95% confidence interval

21. Statistical analysis • Comparison between preop radiographic measurement and postoperative measurement • Paired t-test • Define the cut-off values of the preop radiographic measurements between the corrected and the under-corrected group • ROC curve

22. Results

27. Conclusions • Calcaneal lengthening with concomitant peroneus brevis lengthening is the effective procedure for correcting planovalgus foot deformity while preserving subtalar joint motion in patients with cerebral palsy.

28. Conclusions • For the patients with more than 23˚of AP talus-first MT angle, more than 36˚of Lat. talus-first MT angle, and more than 72% of NC overlap, the additional procedures should be considered due to the possibilities of insufficient correction with calcaneal lengthening alone.

29. Thank you !