Ki Hyuk Sung, MD PhD, Soon-Sun Kwon, PhD*, Gyeong Hee Cho, PT PhD, Chin Youb Chung, MD PhD, Kyoung Min Lee, MD PhD,

Sang Ho Chun, MD, Sangyeop Shin, MD, Hyun Choi, MD, Moon Seok Park, MD PhD Department of orthopaedic surgery, Seoul National University Bundang Hospital, Gyeonggi, Korea

*Depratment of Mathematics, Ajou University, Geyonggi, Korea

Objectives

To evaluated the long-term outcomes at more than 10 years

after femoral derotation osteotomy (FDO) in children with

cerebral palsy (CP)

Methods

Inclusion criteria

1) consecutive ambulatory patients with spastic CP

2) patients who underwent single event multilevel surgery including

FDO

3) patients who underwent 3D gait analyses preoperatively and at 1

year and more than 10 years postoperatively

FDO

• Indication: in-toeing gait with increased femoral anteversion and

internal foot progression with increased hip internal rotation

• At intertrochanteric level with the patient in the prone position

• Goal: femoral anteversion of 15°

• Amount of derotation: determined by intraoperative modified

trochanteric prominence angle test

Outcome measures: mean internal hip rotation, mean foot

progression in stance phase, mean pelvic rotation, gait

deviation index (GDI)

Results

Improvement of mean hip rotation after FDO was significantly

improved at final follow-up. Improvement of mean foot

progression angle and GDI after FDO was maintained at final

follow-up.

No patients underwent revision surgery due to recurrence of

rotation deformity

Conclusions

FDO performed in the prone position provides favorable long-term

outcomes at more than 10 years postoperatively, without recurrence of

rotation deformity in children with CP.

To avoid under-correction or recurrence due to insufficient derotation,

surgeons should consider not only dynamic gait analysis findings but

also the measurement of anatomic femoral anteversion during

intraoperative derotation.

This research was supported by Basic Science Research Program through the National Research

Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(No. NRF-

2017R1A2B4007412)

Presenter: Moon Seok Park, MD, E-mail: pmsmed@gmail.com

Table 3. Factors affecting GDI score and transverse kinematics of 3D gait analysis after FDO

Figure 2. In all graphs, the solid black line represents the average value, and the grey area

represents one standard deviation. The positive values indicate internal rotation.

Figure 1. (A) A guide pin is inserted parallel to the femoral neck axis on a frog-leg

lateral hip radiograph, and intertrochanteric osteotomy and derotation are

performed until the modified TPAT reaches 15°. (B) The modified TPAT is defined as the angle between a vertical line and the long

axis of the leg when a guide pin is located horizontal to the ground.

Value

Sex (male/female) 19/ 15

Laterality (right/left) 24/ 29

Anatomical type (hemiplegia/diplegia) 9 / 25

GMFCS level (I/II) 14 / 20

Age at surgery (years) 7.8 ± 3.0 (4.9 - 17.1)

Age at final follow-up (years) 20.8± 3.8 (16.1 – 30.4)

Follow-up duration (years) 12.9 ± 2.7 (10.0 - 21.0)

Table 2. Kinematic data and GDI before and after FDO

Parameters Preop Postop

1Y

Final

follow-up

p-value

Pre-1Y Pre-10Y 1Y-final RM-

ANOVA

Mean pelvic rotation (̊ ) -2.5±7.7 0.3±5.4 1.7±6.2 0.008 0.004 0.525 0.001

Mean hip rotation (̊ ) 9.6±12.2 3.1±9.3 -5.9±8.1 0.004 <0.001 <0.001 0.001

Mean foot

progression in stance (̊ ) 7.9±16.3 -7.4±11.3 -10.9±11.3 <0.001 <0.001 0.094 0.001

GDI 68.2±8.7 83.4±8.5 82.3 ± 9.5 <0.001 <0.001 1.000 0.001

Mean

hip rotation (°)

Foot progression

in stance (°)

Mean

pelvic rotation (°) GDI

Estimation SE p Estimation SE p Estimation SE p Estimation SE p

Follow up

(year) -0.85 0.14 <0.001 -0.33 0.13 0.016 0.06 0.09 0.490 -0.12 0.11 0.268

Sex

(Male) 0.85 2.01 0.686 -6.41 3.84 0.100 -0.34 1.21 0.778 2.19 2.13 0.308

Age at

Surgery 0.41 0.35 0.243 -0.43 0.64 0.509 -0.11 0.22 0.610 -0.56 0.36 0.132

Side (Rt) -1.86 1.66 0.278 0.241 1.72 0.892 2.14 1.08 0.063 0.18 1.28 0.888

Anatomical

type

(hemi)

-0.88 3.27 0.788 -2.72 5.85 0.643 -2.52 1.66 0.134 6.43 2.75 0.022

GMFCS

level (I) 3.51 2.29 0.130 2.02 4.16 0.630 -2.98 1.37 0.034 3.47 2.40 0.154

Table 1. Patients demographics