Asymmetric pelvic and hip rotation in children with bilateral cerebral palsy: uni- or bilateral femoral derotation osteotomy?

Predictors of Changes in Pelvic Rotation after Surgery with or without Femoral Derotational Osteotomy in Ambulatory Children with Cerebral Palsy

Asymmetry of pelvic rotation affects function. However, predicting the post-operative changes in pelvic rotation is difficult as the root causes are complex and likely multifactorial. This retrospective study explored potential predictors of the changes in pelvic rotation after surgery with or without femoral derotational osteotomy (FDRO) in ambulatory children with cerebral palsy (CP). The change in the mean pelvic rotation angle during the gait cycle, pre- to post-operatively, was examined based on the type of surgery (with or without FDRO) and CP distribution (unilateral or bilateral involvement). In unilaterally involved patients, pelvic rotation changed towards normal with FDRO (p = 0.04), whereas patients who did not undergo FDRO showed a significant worsening of pelvic asymmetry (p = 0.02). In bilaterally involved patients, the changes in pelvic rotation did not differ based on FDRO (p = 0.84). Pelvic rotation corrected more with a greater pre-operative asymmetry (β = -0.21, SE = 0.10, p = 0.03). Sex, age at surgery, GMFCS level, and follow-up time did not impact the change in pelvic rotation. For children with hemiplegia, internal hip rotation might cause compensatory deviation in pelvic rotation, which could be improved with surgical correction of the hip. The predicted changes in pelvic rotation should be considered when planning surgery for children with CP.

Effects of artificially induced bilateral internal rotation gait on gait kinematics and kinetics

BACKGROUND

Bilateral internal rotation gait is a common gait abnormality in children with bilateral cerebral palsy, but still not fully understood.

RESEARCH QUESTION

The aim of this clinical study was to analyze the effects of artificially induced bilateral internal rotation gait on kinematics and kinetics. Our hypothesis was, that the internal rotation gait defined as increased dynamic internal hip rotation itself causes significant alterations in gait kinematics and kinetics.

METHODS

30 typically developing children with a mean age of 12 (SD 3) years (range 8 - 16) performed three-dimensional gait analysis in two different conditions: with unaffected gait and with artificially induced bilateral internal rotation gait with two rotation bandages worn in order to internally rotate the hips. Kinematic and kinetic changes between these two conditions were calculated and compared using a mixed linear model with "gait condition" as fixed effect and both "limb" and "patient" as random effects.

RESULTS

The rotation bandages induced a significant increase in internal hip rotation and foot progression angle towards internal without affecting pelvic rotation. The peak hip internal rotator moment during loading response and the peak hip external rotator moment during the first half of stance phase increased significantly and the peak hip internal rotator moment during the second half of stance phase decreased significantly. Anterior pelvic tilt, hip flexion, knee flexion and ankle dorsiflexion increased significantly. The first peak of the frontal hip moment decreased, and the second increased significantly. The second peak of the frontal knee moment decreased significantly, while the first didn't change significantly.

SIGNIFICANCE

The data suggest, that the bilaterally increased dynamic internal hip rotation itself has a relevant impact on frontal hip moments. The increased anterior pelvic tilt, hip and knee flexion may be either induced by the pull of the rotation bandage or a secondary gait deviation.

Long-term functional outcomes after an external femoral derotation osteotomy in individuals with cerebral palsy

BACKGROUND

It is unknown how a femoral derotation osteotomy (FDO) during childhood affects functional outcomes in adulthood among individuals with bilateral cerebral palsy (CP).

RESEARCH QUESTIONS

How do long-term functional outcomes after an FDO compare to matched individuals who did not have an FDO? How do outcomes change over time?

METHODS

We queried the gait laboratory database for individuals who underwent an external FDO in childhood and were currently ≥25 years old. Participants returned for a long-term analysis (gait, physical examination, functional tests, imaging, questionnaires). The matched non-FDO group included only individuals in Gross Motor Function Classification System levels I-II, yielding three groups (non-FDO I-II, FDO I-II, FDO III-IV).

RESULTS

Sixty-one adults (11 non-FDO, 34 FDO I-II, 16 FDO III-IV) returned 13-25 years after baseline (non-FDO) or surgery (FDO). The non-FDO and FDO I-II groups were matched at baseline on most variables, except the FDO group had weaker hip abductors. At long-term, groups were similar on gait variables (median long-term hip rotation [primary outcome], non-FDO: -4°, FDO I-II: -4°, FDO III-IV: -5°), hip abduction test, fear of falling, and most pain measures despite anteversion being 29° greater in the non-FDO group. The FDO I-II group reported more falls than the non-FDO group. All groups improved on hip rotation, foot progression, and hip abductor strength. Speed and step length decreased/tended to decrease for all three groups. Hip abduction moment and gait deviation index did not change. Improvements in the FDO groups were maintained from short- to long-term.

SIGNIFICANCE

These results challenge the notion that an FDO is necessary to correct mean stance hip rotation for higher functioning individuals since nearly identical results were achieved by adulthood in the non-FDO I-II group. However, an FDO provides improvement earlier and maintenance from short- to long-term. This should factor into the shared decision-making process.

Kinematics after unilateral femoral derotation osteotomy in children with diplegic cerebral palsy

INTRODUCTION

Femoral derotation osteotomy (FDO) is a treatment option in children and adolescents with cerebral palsy who have transverse plane deviations in their lower limbs. When the transverse kinematic deviations are asymmetric, the osteotomy indication can be unilateral.

HYPOTHESIS

Unilateral FDO has a kinematic effect on ipsilateral transverse plane deviations along with those of the pelvis and contralateral side.

MATERIALS AND METHODS

Among the 170 diplegic children that our team has operated on, 34 underwent unilateral FDO. Their mean age was 12.5±2.7 years; 12 were GMFCS level I and 22 were level II. The kinematic changes 18 months after surgery were evaluated with a paired Student's t test and correlations were determined with the Spearman test (p<0.05). The mean preoperative femoral anteversion was 45°±8°. In terms of kinematics, on the operated side, the children had a mean internal hip rotation of 26°±7°, external pelvis rotation of -8°±6° and inward foot progression angle of 8°±12°.

RESULTS

The anteversion was corrected surgically by -28°±5°. Postoperatively, the ipsilateral hip rotation (10°±10°), pelvis rotation (-2°±5°) and foot rotation (6°±12°) were significantly improved. No correlations were identified between the resulting kinematic parameters and surgical correction. The five feet that had inward rotation (13°±9°) were improved to (-5°±7°).

DISCUSSION

Unilateral FDO of the hip in patients with asymmetry not only reduces the internal rotation of the operated hip, it also normalizes the rotation of the pelvis and both feet. However, these improvements are not directly related to the amount of surgical correction.

LEVEL OF EVIDENCE

IV: case series.

The long-term outcome of pelvic asymmetry during gait in children with cerebral palsy following unilateral femoral derotation osteotomy

In this retrospective study, children with cerebral palsy underwent a unilateral femoral derotation osteotomy and had a preoperative (PO), short-term postoperative (1-3 years), and a long-term postoperative (≥5 years) gait analysis. Patients were subdivided into groups by the PO pelvic presentation and Gross Motor Function Classification System level. In children with PO pelvic external rotation, femoral derotation osteotomy decreased the hip internal rotation and decreased the pelvic external rotation. These results could influence surgical planning to achieve long-term pelvic asymmetry.

Clinical and Gait Parameters Related to Pelvic Retraction in Patients with Spastic Hemiplegia

Pelvic retraction during walking is a common finding seen in patients with spastic hemiplegia. However, potential factors related to this condition have not been comprehensively examined in a systemic manner in previous studies. The purpose of this study was to elucidate any clinical and gait parameters related to pelvic retraction in patients with hemiplegic cerebral palsy. A total of 212 independent ambulatory patients were enrolled in the study. Group I consisted of 113 patients who had persistent pelvic retraction, and Group II of 99 with a normal range of pelvic rotation throughout the gait cycle as evidenced by kinematic analysis. A multivariate logistic regression analysis using a clustering technique was performed, with use of eight gait factors and five clinical factors. Decreased ankle dorsiflexion, increased hip internal rotation, increased anterior pelvic tilt, the Winters classification type II, and asymmetrical posturing of the upper extremity during gait were found to be related to pelvic retraction. This is the only study including a broader array of assessment domains of both clinical and gait parameters with a considerably large and homogenous population with hemiplegia. Further studies will be needed to see whether the rectification of those parameters may improve abnormal gait and pelvic retraction in hemiplegia.

Proximal versus distal femoral derotation osteotomy in bilateral cerebral palsy

AIM

Femoral derotation osteotomy (FDO) can be conducted either proximally or distally to correct internal rotation gait (IRG) and increased anteversion in children with cerebral palsy (CP). Previous studies with limited numbers of participants have presented comparable short-term static and kinematic outcomes for both techniques. The objective of this retrospective multicentre study was to verify this thesis with a larger number of patients.

METHOD

In total, 119 children with CP and IRG were included after matching the groups on preoperative mean stance hip rotation: 67 intertrochanteric (proximal group) FDO (average age at surgery 9y [SD 3y]); 52 supracondylar (distal group) FDO (average age at surgery 12y [SD 3y]). One random limb of each child was analyzed. Both transverse plane kinematic gait data and torsional parameters of clinical examination were assessed preoperatively and postoperatively.

RESULTS

On average, both groups' mean hip rotation and midpoint of hip rotation improved postoperatively, and groups did not differ preoperatively or postoperatively for these variables (p>0.05).

INTERPRETATION

The osteotomy location does not influence short-term gait kinematics nor static measurements. Therefore, the choice of performing proximal or distal FDO in children with CP for treatment of IRG and increased anteversion should be motivated by considerations other than these outcome parameters.

WHAT THIS PAPER ADDS

Femoral derotation osteotomy (FDO) location does not influence mean stance hip rotation in cerebral palsy (CP). FDO location does not influence mid-point hip rotation in CP. FDO location should be motivated by concomitant procedures performed.

Quantitative Assessment of Knee Progression Angle During Gait in Children With Cerebral Palsy

BACKGROUND

Abnormal hip rotation is a common deviation in children with cerebral palsy (CP). Clinicians typically assess hip rotation during gait by observing the direction that the patella points relative to the path of walking, which is referred to as the knee progression angle (KPA). Two kinematic methods for calculating the KPA are compared with each other. Video-based qualitative assessment of KPA is compared with the quantitative methods to determine reliability and validity.

METHODS

The KPA was calculated by both direct and indirect methods for 32 typically developing (TD) children and a convenience cohort of 43 children with hemiplegic type CP. An additional convenience cohort of 26 children with hemiplegic type CP was selected for qualitative assessment of KPA, performed by 3 experienced clinicians, using 3 categories (internal, >10 degrees; neutral, -10 to 10 degrees; and external, >-10 degrees).

RESULTS

Root mean square (RMS) analysis comparing the direct and indirect KPAs was 1.14+0.43 degrees for TD children, and 1.75+1.54 degrees for the affected side of children with CP. The difference in RMS among the 2 groups was statistically, but not clinically, significant (P=0.019). Intraclass correlation coefficient revealed excellent agreement between the direct and indirect methods of KPA for TD and CP children (0.996 and 0.992, respectively; P<0.001).For the qualitative assessment of KPA there was complete agreement among all examiners for 17 of 26 cases (65%). Direct KPA matched for 49 of 78 observations (63%) and indirect KPA matched for 52 of 78 observations (67%).

CONCLUSIONS

The RMS analysis of direct and indirect methods for KPA was statistically but not clinically significant, which supports the use of either method based upon availability. Video-based qualitative assessment of KPA showed moderate reliability and validity. The differences between observed and calculated KPA indicate the need for caution when relying on visual assessments for clinical interpretation, and demonstrate the value of adding KPA calculation to standard kinematic analysis.

LEVEL OF EVIDENCE

Level II-diagnostic test.

Preoperative hip rotation moments do not predict long-term development after femoral derotation osteotomy in children with cerebral palsy

BACKGROUND

Femoral derotation osteotomy (FDO) is the standard treatment for internal rotation gait (IRG) in children with cerebral palsy (CP) although high rates of recurrence have been reported recently. Various factors associated with recurrence could be identified, but no predictor named.

RESEARCH QUESTIONS

Does FDO lead to a change of internal transversal hip moments? Are preoperative internal transversal hip moments a predictor for recurrence of IRG?

METHODS

41 children with spastic bilateral CP and 72 limbs that received a FDO (10.4 ± 2.7 years at surgery) were included retrospectively. Kinematic data were analyzed pre- (2 ± 3 months), postoperatively (12 ± 3 months) and at long-term follow-up (at least five years postoperatively; 84 ± 13 months), internal transversal hip moments were analyzed pre- and postoperatively.

RESULTS

The maximum peaks of the internal hip rotation moment during loading response decreased significantly (p = 0.003). The minimum during the second half of the stance phase increased significantly (p = 0.004) and the initially internal externally rotating moment changed to an internal internally rotating moment. No correlation between changes in hip rotation from postoperatively to the long-term follow-up and the preoperative internal hip rotation moment could be identified.

SIGNIFICANCE

FDO leads to changes in internal hip rotation moments. Preoperative internal hip rotation moments can't be used as predicting factor for recurrence of IRG. The data suggest, that recurrence of IRG depends less on patient specific motion patterns, but more on the time point of surgery and the therapy of all concomitant deformities during SEMLS.

Long-term development of overcorrection after femoral derotation osteotomy in children with cerebral palsy

BACKGROUND

Recent studies showed rates of recurrence of internal rotation gait (IRG) after femoral derotation osteotomy (FDO) up to 40%. Some surgeons even advice overcorrection during FDO to avoid a later recurrence.

RESEARCH QUESTION

Evaluation of the long-term development of limbs with initial overcorrection after FDO.

METHODS

29 limbs of 20 children (9.9 ± 3.2 years at surgery) with IRG, cerebral palsy (CP) and more than 5° external hip rotation postoperatively were included retrospectively. A gait analysis and clinical examination were performed preoperatively (less than one year, E0), postoperatively (9-23 months, E1) and at the long-term follow-up (at least five years postoperatively, E2). Differences between those children that remained overcorrected at E2 and those with a hip rotation within normal range at E2 were evaluated.

RESULTS

At E2 41% of these limbs remained overcorrected, 52% showed a hip rotation within normal range and 7% showed recurrence of IRG. A comparison of those limbs that remained overcorrected and those ending within normal range revealed neither a difference in age at surgery nor in static and dynamic torsional parameters at E0 and E1 except for pelvic rotation. A significantly larger pelvic internal rotation at E1 for those with remaining overcorrection could be identified.

SIGNIFICANCE

A general overcorrection during FDO in children with CP to avoid recurrence of IRG cannot be recommended, as 41% remain overcorrected. Preoperative predictors for long-term development couldn't be identified. If pelvic mal-rotation is corrected, hip rotation may change into normal range over the time in combination with the development of a flexed knee gait.

Changes in hip abductor moment 3 or more years after femoral derotation osteotomy among individuals with cerebral palsy

AIM

To examine the effect of femoral derotation osteotomy (FDO) on dimensionless hip abductor moment during gait in children with cerebral palsy.

METHODS

We retrospectively analyzed data from independent ambulators within our database. Postoperative visits 1 year (short-term) and at least 3 years (mid-term) were analyzed. We estimated the coronal plane hip abductor moment arm based on musculoskeletal modeling that accounted for anteversion and hip rotation.

RESULTS

There were 140 individuals with a short-term analysis (77 males, 63 females; age at surgery 9y 11mo [range 4y 5mo-17y 5mo]) and 29 with mid-term analysis (15 males, 14 females; age at surgery 8y 7mo [range 4y 5mo-13y 1mo]). At short-term, anteversion and internal hip rotation decreased 35° and 13° respectively, which increased median (IQR) moment arms from 20 (23) per cent below normal to 2 (12) per cent above normal. Dimensionless mean hip abductor moment remained unchanged at short-term. Mid-term anteversion did not change but hip rotation increased 8° and hip abductor moment increased to 0.040 (0.029). There was no change in pelvic and trunk obliquity, although hip abductor strength increased and walking velocity decreased at mid-term.

INTERPRETATION

The unexpected lack of improvement in hip abductor moment from pre- to short-term may be caused by gait compensations that unload the hip. The increase in hip abductor moment beyond 3 years postoperatively underscores the benefits of an FDO into adolescence for independent ambulating individuals with cerebral palsy.

Correlation between transverse plan kinematics and foot progression angle in children with spastic diplegia

In diplegic patients, the orientation of foot progression depends on multiple factors. We investigated the relationship between foot progression alignment, hip and pelvic rotations during gait, femoral anteversion, and tibial torsion. Kinematic and clinical parameters were evaluated for 114 children who walked independently and had not undergone previous surgery. Causes of intoeing presented combined in 72% of cases. Internal foot progression correlated with internal hip rotation and showed an inverse correlation with tibial torsion. Our results indicate that data from clinical examination and gait analysis should be evaluated carefully before making treatment recommendations, especially in terms of the correction of torsional problems, in patients with cerebral palsy.

Contribution of clinical gait analysis to single-event multi-level surgery in children with cerebral palsy

Clinical gait analysis (CGA) has been proven useful in understanding the gait disturbances seen in children and adolescents with cerebral palsy. Another major benefit provided by CGA is a clinical and scientific evaluation of how orthopaedic surgical procedures modify gait. The information provided by instrumented CGA complements the clinical data, and the two must be interpreted jointly. Although there is some variability in the surgical details of therapeutic strategies, CGA undoubtedly influences the planning of surgery. Although CGA improves surgical outcomes, these remain challenging to predict. CGA seems cost-effective. Internal hip rotation gait is used as an example to illustrate those benefits.

Long-term changes in femoral anteversion and hip rotation following femoral derotational osteotomy in children with cerebral palsy

BACKGROUND

Excessive femoral anteversion is common in cerebral palsy (CP), is often associated with internal hip rotation during gait, and is frequently treated with a femoral derotational osteotomy (FDO). Concerns exist regarding long-term maintenance of surgical outcomes. Past studies report varying rates of recurrence, but none have employed a control group.

METHODS

We conducted a retrospective analysis examining long-term (∼5 years) changes in anteversion and hip rotation following FDO in children with CP. We included a control group that was matched for age and exhibited excessive anteversion (>30°) but did not undergo an FDO. Anteversion, mean stance hip rotation, and rates of problematic remodeling and recurrence were assessed (>15° change and final level outside of normal limits).

RESULTS

The control group was reasonably well matched, but exhibited 9° less anteversion and 3° less internal hip rotation at the pre time point. At a five year follow-up, the FDO group had less anteversion than the control group (20° vs. 35°, p<0.05). The mean stance phase hip rotation did not differ between the groups (4° vs. 5°, p=0.17). Over one third of limbs remained excessively internal in both groups (FDO: 34%, Control: 37%). Rates of problematic recurrence and remodeling were low (0%-11%).

CONCLUSIONS

An FDO is an effective way to correct anteversion in children with CP. Long-term hip rotation is not fully corrected by the procedure, and is not superior to a reasonably well matched control group. Rates of problematic recurrence and remodeling are low, and do not differ between the groups.

Correction of gait after derotation osteotomies in cerebral palsy: Are the effects predictable?

Derotation osteotomies of the femur and tibia are established procedures to improve transverse plane deformities during walking with inwardly pointing knees and in- and out toeing gait. However, effects of femoral derotation osteotomies on gait were reported to be small, and those for the tibia are not known. Therefore, the aim of the study was to show the relation between the amount of intraoperative rotation and the changes during gait for osteotomies at femur and tibia levels, and predict those for the femur from preoperative clinical and gait data. Forty-four patients with spastic cerebral palsy between 6 and 19 years were included, 33 limbs received rotation only at the femur, 8 only at the tibia and 12 limbs at both levels. Gait analysis and clinical testing was performed pre- and 21.4 (SD=1.8) months postoperatively. The amount of intraoperative derotation of the femur showed no significant correlation with the change in hip rotation during walking (R=-0.17, p=0.25), whereas the rotation of the tibia showed an excellent relationship (R=0.84, p<0.001) with the change in knee rotation. Preoperative hip rotation during walking explained only 18% of the variability of the postoperative change in hip rotation during gait. Strength and passive range of motion in hip extension and abduction as well as hip extension or abduction or foot progression during walking did not show any predictive significance. In conclusion changes of knee rotation during gait is directly predictable from the amount of tibial corrections, contrary the change in hip rotation was not related to the amount of femoral derotation, and prediction was only fair.