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

2. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Introduction Medial callosities Hallux valgus Shoe wear Pain Gait disturbance due to lever arm dysfunction

4. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Calcaneal pitch angle

11. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Lateral talocalcaneal angle

12. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Lateral talus-first metatarsal angle

13. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Naviculocuboid overlap (B/A)

14. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Relative calcaneal length (a/b)

15. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Calcaneocuboid subluxation

16. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL AP talus-first metatarsal angle

17. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Operative procedure

18. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL `

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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Reliability of radiographic measurement Inter-observer reliability (3 observer) 36 radiographs ICC (intraclass correlation coefficient) & 95% confidence interval

21. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Results

23. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Table 1. Patients demographics and surgical procedures Gender (M / F)51 / 24 Age (year)11.0±5.2 (range 5.4 to 30.1) Geographic type (hemiplegia/diplegia/triplegia/quadriplegia) 5 / 48 / 3/ 19 Follow-up duration (year)3.1±2.2 (range 0.3 to 8.4) Calcaneal lengthening (bilateral/ unilateral)54 / 21 Number of surgical procedures per patient6.7 ± 3.0 (range 2 to 14) Data are presented as mean ± SD

24. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Table 2. Inter-observer reliability of radiographic parameters Radiographic parametersICC95% CI AP talus-1st metatarsal angle0.7360.595 to 0.844 calcaneal pitch angle0.9180.864 to 0.954 Lateral talocalacneal angle0.7220.521 to 0.848 Lateral talus-1st metatarsal angle0.7930.641 to 0.887 Naviculocuboid overlap0.9150.859 to 0.953 Relative calcaneal length0.8170.709 to 0.895 Calcaneaocoboid subluxation0.7940.673 to 0.881 ICC, intraclass correlation coefficient

25. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Table 3. Change in radiographic measurements after calcaneal lengthening in patients with cerebral palsy ParametersPreoperativePostoperative Mean difference p-value Normal alignment AP talo-1MT (˚)22.3±11.32.4±13.619.9±14.4<0.00110±7.0 CP (˚)2.9±8.87.3±8.1-4.4±7.2<0.00117±6.0 Lat TC (˚)47.0±9.537.9.±9.29.1±8.5<0.00149±6.9 Lat talo-1MT (˚)30.2±15.611.6±13.118.5±13.8<0.00113±7.5 NC overlap (%)69.0±17.237.8±22.131.2±22.9<0.00147±13.8 Relative calcaneal length1.9±0.22.0±0.3-0.1±0.30.016- CC subluxation (˚)0.2±1.51.4±1.9-1.2±1.8<0.001- AP talo-1MT, anteroposterior talus-first metatarsal angle; CP, calcaneal pitch angle; Lat TC, lateral talocalcaneal angle; Lat talo-1MT, lateral talus-first metatarsal angle; NC overlap, naviculocuboid overlap; CC subluxation, calcaneocuboid joint subluxation.

26. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Table 4. Cut-off values of the preoperative radiographic measurements between the corrected and the under-corrected group after calcaneal lengthening in patients with cerebral palsy Parameters No. of subject (corrected group) No. of subject (under-corrected group) Area under the ROC curve 95% CIp- value Cut-off value AP talo-1MT (˚)54210.7290.614 to 0.8250.0001>23˚ Lat talo-1MT (˚)45300.7540.641 to 0.847<0.0001>36˚ NC overlap (%)47280.6450.526 to 0.7520.0319>72% AP talo-1MT, anteroposterior talus-first metatarsal angle; Lat talo-1MT, lateral talus-first metatarsal angle; NC overlap, naviculocuboid overlap; ROC curve, Receiver Operating Characteristic curve.

27. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL 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. SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL ◦ SEOUL NATIONAL UNIVERSITY BUNDANG HOSPITAL Thank you !