Long-term outcome of femoral derotation osteotomy in children with spastic diplegia

A systematic review and meta-analysis of long-term outcomes of femoral derotation surgery for intoeing gait in cerebral palsy

BACKGROUND

Femoral derotation osteotomy is treatment of choice in intoeing gait secondary to cerebral palsy (CP).

RESEARCH QUESTION

The aim of this study was to critically appraise the literature regarding the long-term outcomes of femoral derotation surgery in CP.

METHODS

Electronic databases of PubMed and Scopus was used for the literature review by two researchers independently (SB, SC). The study population included patients of cerebral palsy undergoing femoral derotation surgery. The keywords used were "cerebral palsy", "intoeing gait", "femur anteversion", "hip anteversion", "femur derotation" and "femur osteotomy".

RESULTS

Nine studies which included 657 limbs in 407 patients were selected for this study of which eight were retrospective in nature. The improvement in hip rotation at stance at last follow up (more than five years) maintained a statistical significance (SMD 1.67 95 %CI 1.12-2.22). Similar statistically significant outcomes were noted for foot progression angle (SMD 1.19 95 %CI 0.92-1.47), anteversion (SMD 2.75 95 %CI 1.49-4.01) and total passive internal rotation (SMD 1.71 95 %CI 1.19-2.22).

SIGNIFICANCE

Femoral derotation surgery is the procedure of choice for correction of intoeing gait in CP. Even though, there is deterioration of results on long-term as compared to short term, majority of the patients shall maintain overall correction without recurrence of an intoeing gait. Future studies with uniform criteria for defining recurrence on the basis of functional limitations shall provide better idea about the natural course of this procedure.

Functional knee joint axis calibration and outcome after femoral derotation in patients with cerebral palsy

BACKGROUND

Patients with cerebral palsy and increased femoral anteversion frequently show disturbing internal rotation gait which may be treated via femoral derotation osteotomy (FDO). A recent study monitored that hip rotation in gait may heavily depend on the procedure by which it is being determined. Traditional measures using the femoral epicondyles as reference for the knee axis (CONV) resulted in more severe transverse plane deviations compared to those using a functional method (FUNC) with relevant implications for treatment indication of FDO.

RESEARCH QUESTION

Is mean hip rotation in stance (mHipRotSt) as obtained via FUNC the more sensitive measure for explaining functional changes after FDO compared to CONV method taking the femoral epicondyles as reference for the knee axis?

METHODS

3D-gait analysis before and one year after FDO was performed in fourteen patients including functional joint axis determination of the knee of which MR imaging was available in eight patients both pre- and postoperatively. Transverse plane gait parameters were calculated using both approaches (CONV, FUNC). Differences between examinations as well as between methods were determined.

RESULTS

Changes in femoral anteversion as measured by MR reasonably well confirm the structural changes as measured clinically and intraoperatively. The average change in mHipRotSt across the group was substantially smaller than the structural change implies. Further, using the FUNC approach led to much smaller values compared to when using the CONV approach. We address this to a mismatch between the axes determined in each method.

SIGNIFICANCE

In the presence of femoral deformity, the knee joint axis as determined via a functional method together with the conventional method (femoral epicondyles for the knee axis) allows to quantify knee rotation independent of torsional parameters of the tibia. It may therefore help to better quantify rotational malalignments in gait and improve decision making of FDO.

A 10.5-year follow-up of walking with unilateral spastic cerebral palsy

Purpose

The purpose of this study was to describe gait evolution in patients with unilateral spastic cerebral palsy (USCP) using modified Gait Profile Score (mGPS without hip rotation), Gait Variable Score (GVS), walking speed, and the observed effects of single-level surgery (SLS) after 10 years.

Methods

Fifty-two patients with USCP (Gross Motor Function Classification System I) and data from two Clinical Gait Analyses (CGAs) were included. The evolution of patients' mGPS, GVS, and walking speed were calculated. Two "no surgery" and "single-level surgery" patient categories were analyzed. Paired t-tests were used to compare the data between CGAs and as a function of treatment category. Pearson's correlations were used to examine relationships between baseline values and evolutions in mGPS and walking speed.

Results

Mean ages (SD) at first and last CGAs were 9.3 (3.2) and 19.7 (6.0) years old, respectively, with an average follow-up of 10.5 (5.6) years. Mean mGPS for the patients' affected side was significantly lower at the last CGA for the full cohort: baseline = 8.5° (2.1) versus follow-up = 7.2° (1.6), effect size = 0.73, p < 0.001. Significant improvements in mGPS and GVS for ankle and foot progression were found for the SLS group. The mGPS change and mGPS at baseline (r = -0.79, p < 0.001) were negatively correlated.

Conclusions

SLS patients demonstrated a positive long-term change in gait pattern over time. The group that had undergone surgery had worse gait scores at baseline than the group that had not, but the SLS group's last CGA scores were relatively closer to those of the "no surgery" group.

Level of evidence

This was a retrospective comparative therapeutic study (level III).

Increased Femoral Anteversion Does Not Lead to Increased Joint Forces During Gait in a Cohort of Adolescent Patients

Orthopedic complications were previously reported for patients with increased femoral anteversion. A more comprehensive analysis of the influence of increased femoral anteversion on joint loading in these patients is required to better understand the pathology and its clinical management. Therefore, the aim was to investigate lower-limb kinematics, joint moments and forces during gait in adolescent patients with increased, isolated femoral anteversion compared to typically developing controls. Secondly, relationships between the joint loads experienced by the patients and different morphological and kinematic features were investigated. Patients with increased femoral anteversion (n = 42, 12.8 ± 1.9 years, femoral anteversion: 39.6 ± 6.9°) were compared to typically developing controls (n = 9, 12.0 ± 3.0 years, femoral anteversion: 18.7 ± 4.1°). Hip and knee joint kinematics and kinetics were calculated using subject-specific musculoskeletal models. Differences between patients and controls in the investigated outcome variables (joint kinematics, moments, and forces) were evaluated through statistical parametric mapping with Hotelling T2 and t-tests (α = 0.05). Canonical correlation analyses (CCAs) and regression analyses were used to evaluate within the patients’ cohort the effect of different morphological and kinematic predictors on the outcome variables. Predicted compressive proximo-distal loads in both hip and knee joints were significantly reduced in patients compared to controls. A gait pattern characterized by increased knee flexion during terminal stance (KneeFlex_tSt) was significantly correlated with hip and knee forces, as well as with the resultant force exerted by the quadriceps on the patella. On the other hand, hip internal rotation and in-toeing, did not affect the loads in the joints. Based on the finding of the CCAs and linear regression analyses, patients were further divided into two subgroups based KneeFlex_tSt. Patients with excessive KneeFlex_tSt presented a significantly higher femoral anteversion than those with normal KneeFlex_tSt. Patients with excessive KneeFlex_tSt presented significantly larger quadriceps forces on the patella and a larger posteriorly-oriented shear force at the knee, compared to patients with normal KneeFlex_tSt, but both patients’ subgroups presented only limited differences in terms of joint loading compared to controls. This study showed that an altered femoral morphology does not necessarily lead to an increased risk of joint overloading, but instead patient-specific kinematics should be considered.

Femoral derotation osteotomy-Does intraoperative electromagnetic tracking reflect the dynamic outcome?

Femoral derotation osteotomy (FDO) is a well-established procedure for the correction of internal rotation gait in children with cerebral palsy. Various studies have demonstrated good results for FDO both in short-term and long-term evaluation with some describing recurrence and over- or under-corrections. The present study evaluates the use of an objective intraoperative derotation measurement through electromagnetic tracking. We report the static and dynamic results of 11 cases with internal rotation gait (8 male, 3 female, mean age 22.2 years), that underwent FDO with intraoperative electromagnetic tracking and conventional goniometric measurement of the correction. The dynamic and static changes were assessed through three-dimensional gait analysis after a mean of 12 months after surgery and rotational imaging preoperative and after a mean of eleven days postoperatively. Mean hip rotation in stance significantly decreased from 20.9° (SD 5.9) to 5.8° (SD 4.7°) after FDO. The mean amount of derotation quantified by electromagnetic tracking was 23.2° (16.5°-28.8°) and 25.1° (20.0°-33.0°) for goniometric measurement. Both measurement modalities showed small differences to rotational imaging (electromagnetic bone tracking [EMT]: 0.72°; goniometer: 1.19°) but a large deviation when compared to three-dimensional gait analysis (EMT: 8.5°, goniometer: 9.1°). In comparison to the static changes and EMT measurement, the dynamic changes measured during 3-D-gait analysis reflected only 66% of the actual derotation performed during surgery. Although electromagnetic tracking allows a precise intraoperative assessment of the derotation during FDO, the amount of intraoperative correction is not reflected in the improvements in three-dimensional gait analysis.

Age related progression of clinical measures and gait in ambulant children and youth with bilateral cerebral palsy without a history of surgical intervention

BACKGROUND

Age related progression needs to be considered when assessing current status and treatment outcomes in cerebral palsy (CP).

RESEARCH QUESTION

What is the association between age, gait kinematics and clinical measures in children with bilateral CP?

METHOD

A retrospective database review was conducted. Subjects with bilateral CP with baseline and follow-up 3D gait analyses, but no history of intervening surgery were identified. Clinical and summary kinematic measures were examined for age related change using repeat measures correlation. Interactions with GMFCS classification and whether surgery was recommended were examined using robust linear regression. Timeseries kinematic data for baseline and most recent follow-up analyses were analysed using statistical parametric mapping.

RESULTS

180 subjects were included. 75% of participants were classified as GMFCS I or II at baseline. Mean time to follow-up was 4.89 (2.8) years (range 1-15.9 years) with a mean age of 6.4 (2.4) at baseline and 11.3 (3.4) at final follow-up. 15.5% of subjects demonstrated an improvement in GMFCS classification while GDI remained stable. Age related progression was noted across many clinical measures with moderate correlations (r ≥ 0.5) noted for reduced popliteal angle, long lever hip abduction and internal hip rotation range. In gait, there was reduced hip extension in late stance (p < 0.001), increased knee flexion in mid-stance (p < 0.001), reduced peak knee flexion in swing (p < 0.001) and increased ankle dorsiflexion in stance (p < 0.001). In the coronal plane, there was reduced hip abduction in swing (p < 0.001). In the transverse plane, increased external rotation of the knee (p < 0.001) and reduced external ankle rotation were noted in early stance and through swing (p < 0.001). There were no changes in foot progression or hip rotation.

SIGNIFICANCE

Individuals with CP show age related progression of clinical and kinematic variables. Treatment can only be deemed successful if outcomes exceed or match these age-related changes.

Rehabilitation After Single-Event Multilevel Surgery for Children and Young Adults With Cerebral Palsy: A Systematic Review

ABSTRACT

This review sought to describe and analyze published protocols for rehabilitation after single-event multilevel surgery for people with cerebral palsy, to identify their differences and limits, and to introduce a common step-by-step framework for future descriptions and assessments of postoperative rehabilitation protocols.The MEDLINE, Embase, CINAHL, and the Cochrane Library databases were searched. Inclusion criteria were as follows: (1) single-event multilevel surgery, (2) full-text reports published after 1985, and (3) articles with a method section describing the rehabilitation protocol. Interventions were coded using the Oxford Levels of Evidence and the Methodological Index for Non-Randomized Studies Index.Twenty-four articles were included in the review. Studies included patients aged 4-30 yrs with spastic cerebral palsy (hemiplegia, diplegia, and quadriplegia). The mean postoperative rehabilitation duration was 4.5 mos, with 4 sessions per week, and rehabilitation took place in a rehabilitation center. This review provides relevant information about the modalities, contents, limits, and difficulties associated with the post-SEMS rehabilitation protocol reported in the literature. Pain was identified as a major problem.A more precise and comprehensive description of post-SEMS rehabilitation protocols would be useful. The proposed five-step framework could be used by future studies to standardize their protocol description in terms of objective, content, and intensity.

Correction of complex three-dimensional deformities at the proximal femur using indirect reduction with angle blade plate and patient-specific instruments: a technical note

BACKGROUND

Corrective osteotomies for complex proximal femoral deformities can be challenging; wherefore, subsidies in preoperative planning and during surgical procedures are considered helpful. Three-dimensional (3D) planning and patient-specific instruments (PSI) are already established in different orthopedic procedures. This study gives an overview on this technique at the proximal femur and proposes a new indirect reduction technique using an angle blade plate.

METHODS

Using computed tomography (CT) data, 3D models are generated serving for the preoperative 3D planning. Different guides are used for registration of the planning to the intraoperative situation and to perform the desired osteotomies with the following reduction task. A new valuable tool to perform the correction is the use of a combined osteotomy and implant-positioning guide, with indirect deformity reduction over an angle blade plate.

RESULTS

An overview of the advantages of 3D planning and the use of PSI in complex corrective osteotomies at the proximal femur is provided. Furthermore, a new technique with indirect deformity reduction over an angle blade plate is introduced.

CONCLUSION

Using 3D planning and PSI for complex corrective osteotomies at the proximal femur can be a useful tool in understanding the individual deformity and performing the aimed deformity reduction. The indirect reduction over the implant is a simple and valuable tool in achieving the desired correction, and concurrently, surgical exposure can be limited to a subvastus approach.

[Dynamic analysis of joint loading due to leg axis deformity in the frontal plane : Relevance of instrumented gait analysis]

BACKGROUND

Instrumented 3D gait analysis (IGA) has been established for the functional evaluation of orthopedic diseases. It can provide valuable additional information beyond conventional static radiographic diagnostics and, thus, contributes to treatment decisions and a successful surgical outcome. Regarding the assessment of leg axis deformities IGA is currently only used in a few specialized centers.

PRACTICE

This article describes the methods used by IGA and shows its benefit for the treatment of leg axis deformities of the knee in the frontal plane. In particular, the calculation of dynamic joint loads provides important insights regarding the development of degenerative joint deformities in the knee joint and, thus, complements the static assessment of the leg axis. A new treatment algorithm for guided growth intervention in children and adolescents by temporary epiphysiodesis is presented. IGA can be particularly useful for clinical decision-making in borderline cases. If there is a discrepancy between the static leg axis and dynamic knee joint loading, IGA can reveal potential compensatory mechanisms during walking.

Proximal femoral derotation osteotomy in children with CP : long term outcome and the role of age at time of surgery

The femoral derotation osteotomy (FDO) is seen as the golden standard treatment in children with cerebral palsy and internal rotated gait. This study provides quantitative evidence in support of the beneficial effect of FDO after long term follow up. Retrospective clinical and kinematic evaluation of 31 CP patients (55 operated limbs) pre-, 1 and 3 years postoperatively after proximal FDO was conducted for a minimal follow-up of 3 years. This group con- sisted of 20 men and 11 women, aged 10.68±3.31 years at the time of surgery. Minimum follow up was 3 years (3.16±0.53 years), with 22 patients (38 operated limbs) having an additional follow up at 5 years (5.02±0.49 years). Age at FU3 and FU5 was 14.06±3.52 years and 15.39±3.08 years respectively. A set of clinical and kinematic parameters were ana- lyzed and showed a significant correction of mean hip rotation and femoral anteversion after FDO. Further plotting of individual data comparing 3 or 5 year postoperative values to 1 year postoperative values showed no further significant changes, indicating sustained correction of internally rotted gait until end of our follow up. Plotting mean hip rotation in stance as well as kinematic knee parameters according to age grouped cohorts could not show age at time of surgery to be a significant factor in recurrence of internally rotated gait or preoperative disturbances of knee motion in the sagittal plane. This study provides quantitative evidence on the beneficial effect of FDO, a surgical technique to improve internally rotated gait in cerebral palsy patients with spastic diplegia. Pre- and postoperative clinical and kinematic parameters are compared and results are discussed. Minimum follow up was 3 years with a mean follow up of 4.65±0.83 years. The effect of age at time of surgery on recurrence and kinematic parameters were studied.

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.

Femoral Derotation Osteotomy Improves Hip and Spine Function in Patients With Increased or Decreased Femoral Torsion

PURPOSE

To evaluate the outcomes of proximal femoral derotation osteotomy (PFDO) on the hip and spine function of patients with abnormal femoral torsion.

METHODS

This retrospective study included patients who underwent PFDO to treat increased or decreased femoral torsion between July 2014 and February 2019. The exclusion criteria were: previous fracture, fixation of slipped capital femoral epiphysis or osteotomy in the ipsilateral femur; PFDO associated to varus or valgus osteotomy; Tönnis grade 2 or 3 osteoarthritis; and PFDO performed to treat knee abnormalities. Hip function was assessed through the modified Harris Hip Score (mHHS). A subgroup of consecutive patients with low back pain before the PFDO and operated after 2017 had the spine function assessed through the Oswestry disability index (ODI).

RESULTS

A total of 37 hips (34 patients) were studied: 15 hips with increased femoral torsion and 22 with decreased femoral torsion. Eight patients were male and 26 were female. The average age at PFDO was 33 years (range, 15-54 years). At a mean follow-up of 24 months (range, 12-65 months), the mean mHHS improved from 58.1 ± 14.3 before PFDO to 82 ± 15.6 at the most recent follow-up (P < .001). Improvement in the mHHS above the minimum clinically important difference (MCID) was observed in 33 hips (89%). In the subgroup of 14 consecutive patients with ODI available, the ODI improved from a mean of 45% ± 16% before the PFDO to 22% ± 17% at the most recent follow-up (P = .001). Nine (64.3%) of the 14 patients presented improvement in the ODI above the MCID. Revision procedure with a larger intramedullary nail was necessary in 2 hips to treat nonunion.

CONCLUSION

Proximal femoral derotation osteotomy improves the hip and spine function in patients with increased or decreased femoral torsion and nonarthritic hips.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Outcomes of isolated soft tissue surgery for in-toeing gait in patients with ambulatory cerebral palsy

BACKGROUND

Soft tissue surgery to address in-toeing gait in young cerebral palsy (CP) patients may be an alternative in some cases to femoral derotation osteotomy (FDO), which is the currently accepted treatment. The relative contribution of muscular contracture, spasticity and bone deformity is still controversial. In this study, we determined the outcomes of soft tissue surgery on hip internal rotation (HIR) when femoral anteversion was less than 45° and the soft tissues were identified as being the cause.

METHODS

This prospective study included select adolescent patients who were operated in the context of single-event multilevel surgery. The soft tissues' contribution to the HIR was identified beforehand. The surgical procedures focused on the hamstrings, adductor magnus and gluteus minimus muscles.

RESULTS

Over a 6-year period, 21 patients (mean age 14 years) and 25 lower limbs were treated. The HIR improved by an average of 17.4°±4.8° (95% CI). The gait deviation index and gait profile score also improved significantly. At a mean follow-up of 36 months, no loss of correction had occurred.

DISCUSSION

In-toeing gait in CP patents is due to the action of retracted and/or spastic muscles and the presence of excessive bone torsion. When femoral anteversion<45°, confirming soft tissue involvement allows us to do a surgical procedure on the soft tissues only to correct the dynamic aspect of HIR. Our findings suggest that, under the right conditions, soft tissue surgery can improve in-toeing gain in the long term. This technique has its place alongside FDO in certain CP patients who do not have severe femoral anteversion.

Biomechanical Comparison of Two Pediatric Blade Plate Designs in Proximal Femoral Osteotomies

BACKGROUND

Blade plates are frequently used for internal fixation following proximal femoral varus rotational osteotomy to treat hip dysplasia in children with cerebral palsy. Recently, cannulated blade plates with the option for a proximal locking screw have demonstrated ease of insertion and low complication rates. Although there are two commonly used blade plates with a proximal screw option, no comparison of their biomechanical profiles has been undertaken.

QUESTIONS/PURPOSES

Our study sought to compare the structural properties under axial loading, as well as the biomechanical contribution of a proximal screw, of two different 90° cannulated blade plates designed for pediatric proximal femurs. Plate A has a hole distal to the blade designed to attach a plate inserter, through which a 3.5-mm non-locking cortical screw could be placed. Plate B has a threaded hole distal to the blade designed to accept a 3.5-mm locking screw.

METHODS

Plate A and plate B were inserted into 33 left pediatric synthetic proximal femurs. Axial loading to failure of plate A with and without a proximal screw was compared to that of plate B with and without a proximal screw. An additional 10 samples using plate B, with and without a proximal locking screw, were tested in tension to quantify the effect of the proximal screw on pullout strength.

RESULTS

Plate B failed at a higher axial load than plate A. The addition of a proximal screw did not affect the axial load to failure for either plate. Pullout testing revealed that blade plates fixed with the proximal screw failed in tension at a significantly higher load (856.3 ± 120.9 N) than those without proximal fixation (68.1 ± 9.3 N, p < 0.001).

CONCLUSIONS

Plate B failed at a higher axial load in biomechanical testing, likely related to differences in its design. The addition of a proximal screw did not increase the axial loading properties of the blade plate construct but did increase the pullout strength by a factor of 12. These results may be used to influence implant selection and post-operative rehabilitation following proximal femoral osteotomies in children.

Follow-up of walking quality after end of growth in 28 children with bilateral cerebral palsy

PURPOSE

Assessment of surgical treatments on gait in patients with bilateral cerebral palsy (CP) is often performed in short-term studies. The purpose of this study was to analyze the influence of single-event multilevel surgery (SEMLS) on long-term evolution of gait using gait deviation index (GDI) and walking speed.

METHODS

In all, 28 patients with bilateral CP (Gross Motor Function Classification System I to III) with two clinical gait analyses (CGA) were included (mean age: 9.0 years (sd 2.9) at the first CGA, 19.6 years (sd 4.1) at the last, all of them at skeletal maturity). GDI, walking speed and their changes were calculated. Statistical analysis was performed to observe differences between baseline and follow-up CGA. Pearson's correlations were conducted to evaluate the associations between GDI and walking speed changes with: GDI at baseline and walking speed at baseline. GDI and walking speed evolution have been analyzed for two groups of patients: with and without SEMLS.

RESULTS

Regardless of the treatment, GDI was significantly higher at follow-up CGA (baseline: 73.1 (sd 13.1) versus follow-up: 80.1 (sd 13.2); p = 0.014). Significant negative correlations were found between GDI change and GDI at baseline (r = -0.52; p = 0.004) and between walking speed change and walking speed at the baseline (r = -0.70; p < 0.001). Regarding the group of patients with or without SEMLS, only significant improvement of GDI was found for patients with SEMLS (at baseline: 69.0 (sd 12.1) versus follow-up: 77.8 (sd 11.2); p < 0.05).

CONCLUSION

Analysis at skeletal maturity showed a gait quality maintained for patients without SEMLS and an improvement for patients with SEMLS.

LEVEL OF EVIDENCE

Level III.

Femoral derotation osteotomy in children with cerebral palsy using the pediatric proximal femoral nail

We designed a pediatric proximal femoral nail (PPFN) to overcome fixation method-related complications when performing femoral derotation osteotomy in cerebral palsy patients. Preliminary results of cerebral palsy patients who underwent femoral derotation osteotomy fixed using PPFN to treat in-toeing were evaluated. Sixteen patients with a mean age of 10 years were included. Mean follow-up duration was 36 months. There was no significant difference in the follow-up neck-shaft angle and articulotrochanteric distance values (P = 0.2 and 0.3). PPFN provides stable fixation, early weight-bearing, reduces soft-tissue disruption while limiting the complications due to fixation technique.

[Torsion and torsional development of the lower extremities]

BACKGROUND

Torsion is a frequent reason for consultation in paediatric orthopaedics. Torsion of the femur and the tibia in children change during growth. Depending on the age and possibility for compensation, this can be reflected in the gait pattern. Different causes can affect the normal development of torsion.

DIAGNOSTICS

In the context of paediatric orthopaedic assessment, the distinction between physiological and pathological torsion is essential. In addition to the patient history and observation of the gait pattern, as well as a detailed clinical examination, additional imaging techniques are used (Rippstein/Dunn, torsional CT/MRI, EOS). The dynamic effect of abnormal torsion on gait is evaluated by instrumented 3D gait analysis.

PATHOGENESIS

Evidence for the long-term significance of torsional deviations and the risk of consequential damage are low. Isolated increased femoral anteversion without accompanying hip dysplasia is fundamentally harmless, corrects during growth and only rarely needs correction in the case of ongoing disturbing gait or knee problems. In contrast, retroversion is likely indicate the development of pre-arthritic deformity and should be observed and treated more carefully. Tibial torsion shows great variability and may influence the development of femoral torsion. Torsional deformities in children with neurological or syndromal conditions are differentiated as when the biomechanical effects of torsions on their gait function are generally more marked and therefore treatment is more frequently necessary.

THERAPY

Conservative treatments cannot be expected to have an effect on the condition of the bones. Correction can only be achieved surgically with a rotational osteotomy. A simple principle underlies the technique, whereas indication and timing are challenging.

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.

Supracondylar femoral rotation osteotomy affects frontal hip kinetics in children with bilateral cerebral palsy

AIM

To evaluate the influence of supracondylar femoral derotation osteotomy (FDO) on hip abduction muscle force and frontal hip moments in children with bilateral cerebral palsy.

METHOD

For this retrospective cohort study 79 children (36 females, 43 males; mean age at surgery 11y [SD 3y]; range 4-17y) with bilateral cerebral palsy and preoperatively and 1-year postoperatively documented frontal hip moments who received supracondylar FDO in 134 limbs were included. The control group consisted of eight children (two females, six males; mean age 11y [SD 4y]; range 5-17y) who received single-event multi-level surgery without FDO.

RESULTS

Hip joint impulse (p<0.001) and the first peak of frontal hip moments (p=0.003) increased, whereas the second peak decreased (p<0.001) from preoperatively to postoperatively. Hip abductor strength improved (p=0.001) from preoperatively to postoperatively.

INTERPRETATION

Despite the compensatory mechanism, frontal hip moments are decreased preoperatively. Supracondylar FDO results in increased frontal hip moments. Changes in anteversion directly influence hip kinetics, although no direct change of the proximal bony geometry is performed.

WHAT THIS PAPER ADDS

Internal rotation gait cannot fully restore the frontal hip moment. Supracondylar femoral derotation osteotomy (FDO) influences frontal hip kinetics in children with bilateral cerebral palsy. Supracondylar FDO changes the curve progression of frontal hip moments. Supracondylar FDO restores the hip abductor moment arm. Supracondylar FDO leads to an increase in hip abductor muscle force.

Recurrent internal hip rotation gait in cerebral palsy: Case reports of two patients

Internal hip rotation in cerebral palsy (CP) is typically treated with a femoral derotation osteotomy. This has been shown to be largely a successful procedure but recurrence rates up to 41% have been reported. Reported risk factors include younger age, reduced hip joint impulse and ankle plantar-flexion. 

We report on two patients with bilateral CP demonstrating recurrent unilateral internal hip rotation despite surgical intervention(s).  Both demonstrate a number of the reported risk factors for recurrence.  In addition, this case report specifically compared gait kinematic patterns pre and post recurrence. On comparing both patient’s hip rotation and ankle dorsi/plantarflexion kinematics they are seen to be almost identical both pre-operatively and post-operatively. Both patients appear to revert to approximately 30 ^o of internal hip rotation which has been shown to maximise hip abductor function. Therefore, this case report suggests that surgical derotation in isolation is unlikely to be successful in this group and we suggest that this hip and ankle pattern may help predict recurrence in unilateral internal hip rotation.

Recurrent internal hip rotation gait in cerebral palsy: Report of two patients

Internal hip rotation in cerebral palsy (CP) is typically treated with a femoral derotation osteotomy. This has been shown to be largely a successful procedure but recurrence rates up to 41% have been reported. Reported risk factors include younger age, reduced hip joint impulse and ankle plantar-flexion.  We report on two patients with bilateral CP demonstrating recurrent unilateral internal hip rotation despite surgical intervention(s).  Both demonstrate a number of the reported risk factors for recurrence.  In addition, this case report specifically compared gait kinematic patterns pre and post recurrence. On comparing both patient’s hip rotation and ankle dorsi/plantarflexion kinematics they are seen to be almost identical both pre-operatively and post-operatively. Both patients appear to revert to approximately 30o of internal hip rotation which has been shown to maximise hip abductor function. Therefore, surgical derotation in isolation is unlikely to be successful in this group and we suggest that this hip and ankle pattern may help predict recurrence in unilateral internal hip rotation.

Knee Pain and Activity Outcomes After Femoral Derotation Osteotomy for Excessive Femoral Anteversion

BACKGROUND

Excessive femoral anteversion is a developmental condition that can become symptomatic into adolescence and manifest as anterior knee pain, tripping, and or problems with sports. Femoral derotational osteotomy about an antegrade intramedullary nail (IMN) is an accepted option to treat this condition. This is the first report of the clinical and functional outcomes of treatment of excessive anteversion with femoral derotational osteotomy stabilized with an IMN.

METHODS

We prospectively enrolled 28 consecutive patients between 2013 and 2014 who underwent derotational osteotomy. Physical examination measures were used to calculate the amount of angular correction with focus on internal and external rotation of the hip, as well as the trochanteric prominence angle test of femoral anteversion. The International Knee Documentation Committee-9, Marx, and Tegner activity scales were 3 patient-reported outcomes recorded.

RESULTS

After femoral derotation osteotomy over an IMN, femoral anteversion, as measured by the trochanteric prominence angle, improved an average of 29 degrees (P<0.0001). At 1-year minimum follow-up, 22 of 28 subjects (78.5%) demonstrated a mean significant improvement of 13 points for International Knee Documentation Committee-9 (SD=15.4, P=0.0007), which surpassed the level of minimal clinically important change. Furthermore, the Tegner inventory scores for the cohort improved by an average of 1.9 activity levels (SD=2.4, P=0.0012).

CONCLUSIONS

For adolescents with symptomatic excessive femoral anteversion, derotational osteotomy over an IMN offers a reliable surgical option that provides predictable deformity correction and significant improvements in both function and pain scales.

LEVELS OF EVIDENCE

Level II-prospective, consecutive, nonrandomized, internally controlled cohort study.

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.

The effect of the Majestro-Frost procedure on internal hip rotation during gait in patients with cerebral palsy

BACKGROUND

Muscle imbalance is related to persistent internal hip rotation (IHR) after femoral derotation osteotomy (FDO) in cerebral palsy (CP). The aim of this study was to evaluate the effect of the Majestro-Frost soft tissue procedure (MFP), which potentially addresses muscle imbalance, on IHR in CP patients during walking.

METHODS

A retrospective study of an existing database (medical records and gait laboratory data) was conducted and a search was performed using the following inclusion criteria: (1) diagnosis of spastic CP, (2) GMFCS levels I-III; (3) mean IHR during stance phase higher than 11° at baseline; (4) individuals who received single event multilevel orthopedic surgery in the lower limbs and had three-dimensional gait analyses (3DGA) before and after the intervention. Patients who underwent a FDO were excluded. Eighty-three individuals were considered for the study and they were divided into two groups: No MFP (45 patients who did not receive a MFP) and MFP (36 patients who underwent a MFP). A full clinical examination and 3DGA, with kinematics calculated according to a standard software procedure (Plugin Gait), were performed before and after the intervention, and the results were compared.

RESULTS

The studied groups matched regarding demographic data and GMFCS distribution. The mean follow-up time was more than 20 months on both groups. The increase of clinical external hip rotation (EHR) on physical examination was observed only in the MFP group (from 26.4° to 33°, p = 0.002). During gait analysis, IHR decreased from 21.2° to 4.5° in the MFP group (p < 0.001) and from 16.9° to 7.9° in the No MFP group (p < 0.001). The reduction of IHR during gait was more significant in the MFP group (p = 0.001).

SIGNIFICANCE

In the present study, patients who underwent a MFP showed more reduction of IHR during gait than those which did not undergo a MFP.

Long-term outcomes over 10 years after femoral derotation osteotomy in ambulatory children with cerebral palsy

BACKGROUND

Femoral derotation osteotomy (FDO) is generally reported to be excellent for correcting the hip rotation and foot progression angles in children with cerebral palsy (CP). However, it is unclear how long the favorable outcomes are maintained.

RESEARCH QUESTION

This study was performed to evaluate the long-term outcomes at more than 10 years after FDO in children with CP.

METHODS

FDO, as part of single event multilevel surgery to improve gait function, was performed at the intertrochanteric level with the patient in the prone position. The goal of the index surgery was femoral anteversion of 15°, measured using a modified trochanteric prominence angle test intraoperatively. All patients underwent three-dimensional gait analysis preoperatively and at 1 year and over 10 years postoperatively.

RESULTS

Thirty-four ambulatory patients (53 hips) with CP undergoing FDO were included. The mean age at surgery was 7.8 years (SD = 3.0 years) and mean follow-up duration was 12.9 years (SD = 2.7 years). The mean hip rotation decreased significantly from 9.6° preoperatively to 3.1° at 1 year postoperatively (p = 0.004), and decreased significantly to -5.9° at the final follow-up (p < 0.001). The mean foot progression in stance decreased from 7.9° preoperatively to -7.4° at 1 year postoperatively (p < 0.001), and was maintained at -10.9° at the final follow-up. The GDI significantly improved from 68.2 preoperatively to 83.4 1 year postoperatively (p < 0.001), and was maintained at 82.3 at the final follow-up. No patients underwent revision surgery due to recurrence of rotation deformity.

SIGNIFICANCE

Proximal FDO performed in the prone position provides favorable long-term outcomes at more than 10 years postoperatively, without recurrence of rotation deformity. 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.

Gait pathology subtypes are not associated with self-reported fall frequency in children with cerebral palsy

BACKGROUND

Trips and falls are common concerns reported by parents of children with cerebral palsy. Specific gait pathologies (excessive internal hip rotation, intoeing, and stiff knee gait) are anecdotally associated with higher rates of falls.

RESEARCH QUESTION

Is fall frequency higher for the aforementioned gait pathologies?

METHODS

Parent-reported fall frequency from 1063 children with cerebral palsy who also had a three-dimensional gait analysis was retrospectively reviewed. Frequency of 10 common gait pathologies was determined and fall frequency for the gait pathologies of interest were compared to matched control groups. Possible effects of Gross Motor Functional Classification System (GMFCS) level and age on fall frequency were also assessed and matched in the control group, as appropriate.

RESULTS

In general, parent-reported fall frequency increased from GMFCS level I to II and then decreased until level IV. Moreover, younger children tended to report greater fall frequency, though children who reported never falling were of similar age as those who reported weekly falls, resulting in an inverted-U shaped relationship. Children with cerebral palsy who walked with excessive internal hip rotation, excessive intoeing, or stiff knee gait did not report increased fall frequencies compared to other children with cerebral palsy matched on GMFCS level and age that did not walk with those gait patterns. Approximately 35% of children reported never falling, 35% reported falling daily, and 30% reported falling monthly or weekly for each gait pattern. Therefore, elevated fall frequency appears to be a generic problem for most children with CP rather than a function of a specific gait pattern.

SIGNIFICANCE

Clinicians should be aware of these relationships, or lack thereof, when trying to decipher the cause of a child's falling and when determining appropriate interventions. Future studies may seek to more objectively quantify fall frequency, as self-report is the main limitation of this study.

MRI Assessment of Supra- and Infratrochanteric Femoral Torsion: Association With Femoroacetabular Impingement and Hip Dysplasia

OBJECTIVE

The objective of our study was to evaluate a novel measurement technique for assessing the supra- and infratrochanteric components of femoral torsion, establish reference values in healthy volunteers, and compare supra- and infratrochanteric torsion angles in patients with hip dysplasia and patients with femoroacetabular impingement (FAI) with those in healthy volunteers.

MATERIALS AND METHODS

Femoral torsion was assessed in 380 patients and 61 healthy volunteers on MRI. For assessing supra- and infratrochanteric torsion, three measurement techniques (i.e., Kim, simplified Kim, and centroid methods) were evaluated by two readers on 100 patients. The technique with the highest interreader reliability was selected to perform measurements on all patients and volunteers. Supra- and infratrochanteric torsion angles of patients were stratified by hip disorders, which were diagnosed by specialized hip surgeons, and were compared with reference values of healthy volunteers. Statistical analysis included the independent t test, Mann-Whitney U test, and intraclass correlation coefficient (ICC).

RESULTS

The centroid method showed the highest interreader reliability for measuring supra-and infratrochanteric torsion with an ICC of 0.979. The supra- and infratrochanteric torsion values of the volunteers were 31.5° ± 7.4° (mean ± SD) and -18.3° ± 9.9°, respectively. In comparison with the volunteers, patients with hip dysplasia had significantly higher supraand infratrochanteric torsion values of 37.5° ± 10.3° (p = 0.001) and -9.6° ± 11.7° (p < 0.001) and patients with pincer-type FAI had significantly higher supratrochanteric torsion values of 37.8° ± 8.0° (p = 0.002).

CONCLUSION

The supra- and infratrochanteric components of femoral torsion differ substantially between hip disorders: Patients with hip dysplasia have predominantly increased infratrochanteric torsion, whereas patients with pincer-type FAI have increased supratrochanteric torsion. Quantification of separate supra- and infratrochanteric torsion angles allows a more detailed analysis of hip disorders and may influence treatment planning.

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.

Long-term Outcome of Internal Tibial Derotation Osteotomies in Children With Cerebral Palsy

BACKGROUND

External tibial torsion (ETT) is a common bony deformity in children with cerebral palsy (CP). The current recommended treatment is tibial derotation osteotomy (TDO) to improve gait biomechanics. Satisfactory short-term results after TDO have been reported but long-term results have not been studied. The purpose of this study was to evaluate the long-term outcome following TDO to correct ETT in ambulatory children with CP.

METHODS

Following IRB approval, gait kinematics and passive range of motion measurements were retrospectively evaluated in children with spastic CP who underwent TDO due to ETT comparing preoperative (E0), short-term postoperative (E1; 1 to 3 y post), and long-term postoperative (E2; >5 y post) results. Limbs were categorized as corrected, undercorrected, or overcorrected at both E1 and E2, by comparing mean tibial rotation (MTR) in gait to a group of typically developing children. Age at surgery, E0 MTR, E0 gait velocity, gross motor function classification system (GMFCS) score, and foot deformity were evaluated to determine their influence on long-term results.

RESULTS

The study sample consisted of 43 legs (with E0 and E2) and 22 legs (with E0, E1, and E2). The mean age at surgery was 10.3±3.4 years (range, 6 to 19.2 y). In the group MTR trended toward improvement moving from -26±17 degrees (E0, external negative) to -16±16 degrees (E1) and relapsed to -23±17 degrees at the long term (P=0.071, E0/E1; P=0.589, E0/E2). Improvement was also seen in the transmalleolar axis (P=0.074), mean ankle rotation, and mean foot orientation (P<0.05, E0/E2). At the long-term evaluation, 16 legs (37%) were found to be in the kinematic corrected group, 25 legs (58%) in the kinematic undercorrected group, and 2 legs (5%) in the kinematic overcorrected group. There were no significant differences between the corrected and undercorrected groups of children with respect to age at surgery, GMFCS, E0 MTR, gait velocity, or foot deformity.

CONCLUSIONS

Although internal TDO improves ETT in the short term, recurrence is frequent with an apparent developmental trend toward external rotation of the tibia.

LEVELS OF EVIDENCE

Level IV-therapeutic study.

Persistence and Recurrence Following Femoral Derotational Osteotomy in Ambulatory Children With Cerebral Palsy

BACKGROUND

Excessive hip internal rotation is frequently seen in children with cerebral palsy (CP). Femoral derotational osteotomy (FDO) is effective in the short term, but factors associated with long-term correction remain unclear. The purposes of this study were to define the incidence of persistence and recurrence of hip internal rotation following FDO in ambulatory children with CP and to evaluate factors that influence outcome.

METHODS

Following IRB approval, kinematic and passive range of motion (PROM) variables were retrospectively evaluated in children with spastic CP who had FDO to correct hip internal rotation as part of clinical care at a children's specialty hospital. Children included had a preoperative evaluation (Vpre), a short-term postoperative evaluation (Vshort, 1 to 3 y post), and, in some cases, a long-term postoperative evaluation (Vlong, ≥5 y post). Age at surgery, physical exam measures, and kinematics variables were evaluated as predictors for dynamic and static recurrence.

RESULTS

Kinematic hip rotation improved from 14±12 degrees (Vpre; internal positive) to 4±13 degrees (Vshort) and relapsed to 9±15 degrees long term (P<0.05 Vpre/Vshort/Vlong; 99 limbs). Hip PROM midpoint improved from 23±9 degrees (Vpre) to 8±11 degrees (Vshort) and relapsed to 14±13 degrees (P<0.01 Vpre/Vshort/Vlong). Persistent hip internal rotation was noted in 41% (kinematics) and 18% (PROM) of limbs at Vshort (105 children, 178 limbs). Of limbs that showed initial improvement at Vshort (62 children, 95 limbs), recurrence was seen in 40% (kinematic hip rotation) and 39% (hip midpoint) at Vlong. Comparing children who had recurrent hip internal rotation and those who maintained long-term correction, we saw higher levels of spasticity and lower gait velocity in the recurrent group (P<0.05).

CONCLUSIONS

Although FDO is an accepted treatment in children with CP, persistence and recurrence of hip internal rotation can occur. Recurrence is associated with spasticity and slower gait velocity. Predictor variables may be useful for surgeons during preoperative discussions of expected outcome with families of FDO candidates.

LEVEL OF EVIDENCE

Level III.

Electromagnetic tracking for femoral derotation osteotomy-an in vivo study

Femoral derotation osteotomy delivers good to excellent results in the treatment of rotational gait abnormalities and especially in internal rotation gait. The outcome of the procedure has been evaluated in numerous short- and long-term studies. Although reasons for recurrence and over-/under-correction have been unveiled in earlier studies the mechanisms are still not fully understood. False intra-operative assessment of the derotation angle may contribute to imprecise outcomes. In a recent saw-bone study we evaluated an electromagnetic tracking system in comparison to conventional goniometer measurement and a CT reference measurement and found it to be extremely accurate, whereas the use of a conventional goniometer for derotation measurement showed a high inter- and intra-rater variability. The current study evaluates the electromagnetic tracking system for continuous intra-operative derotation control under real OR conditions. Adults (age: 18-40 years) with the diagnosis of internal rotation gait, independent of the underling pathology, undergoing a supracondylar deroation osteotomy were included. A rotational CT scan was conducted before and in close proximity after surgery and the difference served as reference for the electromagnetic tracking results. The results showed a mean deviation of 2.6° (1.2-5.5°) in comparison to the reference measurement of the pre- and post-operative CT scans. The system proved to be stable under OR conditions with a good usability and a small technical footprint. Electromagnetic tracking delivers a precise, reliable, and independent assessment of intra-operative derotation angles in femoral derotation osteotomies. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2652-2657, 2017.

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.

Long-term outcomes of external femoral derotation osteotomies in children with cerebral palsy

External femoral derotation osteotomy (FDO) is an orthopaedic intervention to correct increased femoral anteversion and associated excessive internal hip rotation and internal foot progression during gait in children with cerebral palsy. The resulting functional issues may include clearance problems and hip abductor lever-arm dysfunction. The purpose of this study was to evaluate long-term gait outcomes of FDO. Twenty ambulatory patients (27 sides) with cerebral palsy who underwent pre-operative (P0) and a one year post-operative (P1) gait analysis as part of the standard of care had a second post-operative analysis (P2) approximately 11 years post-surgical intervention. Mean hip rotation in stance showed statistically significant decreases in internal rotation at P1 post-surgical intervention that were maintained long-term (mean hip rotation P0: 21±9, P1: 0±9 and P2: 6±12 degrees internal). Similar results were seen with mean foot progression (P0: 9±16 degrees internal, P1: 14±13 degrees external, P2: 13±16 degrees external). However, 2/27 sides (9%) showed a recurrence of internal hip rotation of >15° at the 11year follow-up. The reasons for this recurrence could include age, surgical location and ongoing disease process all of which need to be further examined. We conclude that FDO can show long-term kinematic and functional benefits when performed in the prepubescent child with cerebral palsy in comparison to the natural progression of of hip rotation in cerebral palsy.

Electromagnetic bone segment tracking to control femoral derotation osteotomy-A saw bone study

Correction of rotational gait abnormalities is common practice in pediatric orthopaedics such as in children with cerebral palsy. Femoral derotation osteotomy is established as a standard treatment, however, different authors reported substantial variability in outcomes following surgery with patients showing over- or under-correction. Only 60% of the applied correction is observed postoperatively, which strongly suggests intraoperative measurement error or loss of correction during surgery. This study was conducted to verify the impact of error sources in the derotation procedure and assess the utility of a newly developed, instrumented measurement system based on electromagnetic tracking aiming to improve the accuracy of rotational correction. A supracondylar derotation osteotomy was performed in 21 artificial femur sawbones and the amount of derotation was quantified during the procedure by the tracking system and by nine raters using a conventional goniometer. Accuracy of both measurement devices was determined by repeated computer tomography scans. Average derotation measured by the tracking system differed by 0.1° ± 1.6° from the defined reference measurement . In contrast, a high inter-rater variability was found in goniometric measurements (range: 10.8° ± 6.9°, mean interquartile distance: 6.6°). During fixation of the osteosynthesis, the tracking system reliably detected unintentional manipulation of the correction angle with a mean absolute change of 4.0° ± 3.2°. Our findings show that conventional control of femoral derotation is subject to relevant observer bias whereas instrumental tracking yields accuracy better than ±2°. The tracking system is a step towards more reliable and safe implementation of femoral correction, promising substantial improvements of patient safety in the future. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1106-1112, 2017.

Proximal femoral osteotomy in children with cerebral palsy: the perspective of the trainee

BACKGROUND

There are a range of implants for fixation of proximal femoral osteotomies (PFOs) in children. We investigated the training experiences and preferences of orthopaedic residents and fellows who were learning PFO, using a fixed angled blade plate (ABP) or a locking, cannulated blade plate (LCBP). We also studied short-term technical and radiographic outcomes.

METHODS

This was a prospective, parallel-group, cohort study of 90 consecutive children and adolescents with cerebral palsy who underwent bilateral PFOs with ABP or LCBP. Surgical trainees completed a questionnaire to document the ease or difficulty of each operative step.

RESULTS

There were 48 boys and 42 girls, with a mean age of eight years and a mean follow-up of 25 months. Trainees preferred the LCBP system for: insertion of the guidewire, the seating chisel and the blade plate, as well as overall technical ease of use (p < 0.001). Radiographic outcomes were similar with no between-group differences for migration percentage (p = 0.996) or neck shaft angle (p = 0.849), but there was a higher prevalence of technical errors in the ABP group.

CONCLUSIONS

Trainee surgeons expressed a preference for LCBPs when learning PFO in children with cerebral palsy. Radiographic outcomes were similar in both groups, with close attending surgeon supervision.

Gait analysis in children with cerebral palsy

Cerebral palsy (CP) children present complex and heterogeneous motor disorders that cause gait deviations.

Clinical gait analysis (CGA) is needed to identify, understand and support the management of gait deviations in CP. CGA assesses a large amount of quantitative data concerning patients’ gait characteristics, such as video, kinematics, kinetics, electromyography and plantar pressure data.

Common gait deviations in CP can be grouped into the gait patterns of spastic hemiplegia (drop foot, equinus with different knee positions) and spastic diplegia (true equinus, jump, apparent equinus and crouch) to facilitate communication. However, gait deviations in CP tend to be a continuum of deviations rather than well delineated groups. To interpret CGA, it is necessary to link gait deviations to clinical impairments and to distinguish primary gait deviations from compensatory strategies.

CGA does not tell us how to treat a CP patient, but can provide objective identification of gait deviations and further the understanding of gait deviations. Numerous treatment options are available to manage gait deviations in CP. Generally, treatments strive to limit secondary deformations, re-establish the lever arm function and preserve muscle strength.

Additional roles of CGA are to better understand the effects of treatments on gait deviations.

Cite this article: Armand S, Decoulon G, Bonnefoy-Mazure A. Gait analysis in children with cerebral palsy. EFORT Open Rev 2016;1:448-460. DOI: 10.1302/2058-5241.1.000052.

Dynamic motor control is associated with treatment outcomes for children with cerebral palsy

AIM

To estimate the impact of dynamic motor control on treatment outcomes in children with cerebral palsy.

METHOD

We used multiple regression on a retrospective cohort of 473 ambulatory children with cerebral palsy who underwent conservative treatment, single-level orthopaedic surgery, single-event multi-level orthopaedic surgery, or selective dorsal rhizotomy. Outcomes included gait pattern, gait speed, energy cost of walking, and the Pediatric Outcomes Data Collection Instrument. Explanatory variables considered were pre-treatment levels of each outcome, treatment group, prior treatment, age, and dynamic motor control computed from surface electromyography using synergy analysis. Effect sizes were estimated from the adjusted response.

RESULTS

Pre-treatment levels had effect sizes 2 to 13 times larger than the next largest variable. Individuals with milder pre-treatment involvement had smaller gains or actual declines. Dynamic motor control was significant in all domains except energy cost. The effect size of dynamic motor control was second only to pre-treatment level, and was substantially larger than the effect size of treatment group for outcomes where both were significant (gait pattern 2:1, gait speed 4:1). The effect of dynamic motor control was independent of treatment group.

INTERPRETATION

Dynamic motor control is an important factor in treatment outcomes. Better dynamic motor control is associated with better outcomes, regardless of treatment.

A Systematic Review of the Effects of Single-Event Multilevel Surgery on Gait Parameters in Children with Spastic Cerebral Palsy

BACKGROUND

Three-dimensional gait analysis (3DGA) is commonly used to assess the effect of orthopedic single-event multilevel surgery (SEMLS) in children with spastic cerebral palsy (CP).

PURPOSE

The purpose of this systematic review is to provide an overview of different orthopedic SEMLS interventions and their effects on 3DGA parameters in children with spastic CP.

METHODS

A comprehensive literature search within six databases revealed 648 records, from which 89 articles were selected for the full-text review and 24 articles (50 studies) included for systematic review. The Oxford Centre for Evidence-Based Medicine Scale and the Methodological Index for Non-Randomized Studies (MINORS) were used to appraise and determine the quality of the studies.

RESULTS

Except for one level II study, all studies were graded as level III according to the Oxford Centre for Evidence-Based Medicine Scale. The MINORS score for comparative studies (n = 6) was on average 15.7/24, while non-comparative studies (n = 18) scored on average 9.8/16. Nineteen kinematic and temporal-distance gait parameters were selected, and a majority of studies reported improvements after SEMLS interventions. The largest improvements were seen in knee range of motion, knee flexion at initial contact and minimal knee flexion in stance phase, ankle dorsiflexion at initial contact, maximum dorsiflexion in stance and in swing phase, hip rotation and foot progression angles. However, changes in 3DGA parameters varied based on the focus of the SEMLS intervention.

DISCUSSION

The current article provides a novel overview of a variety of SEMLS interventions within different SEMLS focus areas and the post-operative changes in 3DGA parameters. This overview will assist clinicians and researchers as a potential theoretical framework to further improve SEMLS techniques within different SEMLS focus groups. In addition, it can also be used as a tool to enhance communication with parents, although the results of the studies can't be generalised and a holistic approach is needed when considering SEMLS in a child with spastic CP.

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.

Femoral derotation osteotomy in adults with cerebral palsy

BACKGROUND

Internal rotation gait constitutes a complex gait disorder in bilateral spastic cerebral palsy (BSCP) including static torsional and dynamic components resulting in lever arm dysfunction. Although femoral derotation osteotomy (FDO) is a standard procedure to correct increased femoral anteversion in children, unpredictable outcome has been reported. The effect of FDO when it is done as part of single-event multilevel surgery (SEMLS) in adulthood has not been investigated.

METHODS

In this study mid-term data of 63 adults with BSCP and internal rotation gait, undergoing SEMLS including FDO were analyzed pre- and 1.7 years postoperatively by clinical examination and 3D-instrumented gait analysis. All legs were categorized as the more or less involved side to consider asymmetry. The mean hip rotation in stance preoperatively and the intraoperative derotation was correlated with the difference pre- and postoperatively.

RESULTS

The group as a whole experienced the following results postoperatively: improved mean hip rotation in stance (p=0.0001), mean foot progression angle (p=0.0001) and a significant improvement of the clinical parameter: passive internal and external hip rotation, midpoint and anteversion (p=0.0001) for both legs separately. With regard to the less and more involved side, clinical and kinematic parameters showed comparable significant changes (p=0.0001). The anteversion improved significantly in proximal compared to distal FDO (p=0.03).

CONCLUSION

This study emphasizes an overall good correction of internal rotation gait in adults with bilateral involvement after FDO. However, the results are more predictable in adults compared to studies reporting outcome after FDO in children.

Biomechanical changes associated with femoral derotational osteotomy

Torsional deformities of the femur in children may occur as a result of either idiopathic or neuromuscular disorders and may be corrected with derotational osteotomies. Regardless of the underlying etiology, neither the effects of the torsional pathologies nor the alterations resulting from corrective osteotomies are well understood. A study of children with isolated femoral anteversion undergoing a single corrective procedure may assist in understanding the biomechanics of the pathology and the efficacy of surgical correction. A multicenter retrospective study included 25 subjects with idiopathic femoral anteversion who underwent femoral derotational osteotomy and had completed pre and postoperative gait analyses. Both changes with surgery and comparisons to typically developing controls were analyzed. Reduced gait pathology and expected improvements in hip rotation and foot progression were found with derotational osteotomy. Overall gait pathology and pathological differences in pelvic tilt, hip flexion moment and knee adduction moment were found comparing anteversion subjects with typically developing subjects. Following surgery, only hip rotation was significantly and clinically different from typically developing subjects, changing from relatively inward to outward. Idiopathic femoral anteversion creates multifaceted and significant alterations to normal gait and should not be considered solely a cosmetic issue. Additionally, the efficacy of derotational osteotomy is illustrated and may be more broadly applied to other conditions where pathologic femoral anteversion is present.

Outcomes of Orthopaedic Surgery With and Without an External Femoral Derotational Osteotomy in Children With Cerebral Palsy

BACKGROUND

Ambulatory children with cerebral palsy (CP) often present with multiple deviations in all planes including increased internal hip rotation during gait. Excessive femoral anteversion is a common cause of deviation managed surgically with an external femoral derotational osteotomy (FDO). The purpose of this study was to evaluate the gait and functional outcomes of a group of subjects with CP who underwent surgical intervention that included an FDO compared with a match group with indications of internal hip rotation that did not receive an FDO.

METHODS

For this retrospective study, subjects were identified from the Motion Analysis Laboratory database that had orthopaedic surgery including an FDO (FDO group). A control group was established from a chart review identifying subjects that had indications for an FDO, but did not have this surgery (No-FDO group). All subjects had preoperative and postoperative gait studies. Subjects categorized as Gross Motor Function Classification System (GMFCS) levels I and II in both FDO and No-FDO groups were combined for analysis. Subjects rated as GMFCS level III were analyzed separately. Preoperative to postoperative kinematic and kinetic variables, Gait Deviation Index, net oxygen cost, and PODCI scores were analyzed with paired t tests.

RESULTS

Typical sagittal plane kinematic variables improved significantly by equivalent magnitudes for both FDO and No-FDO groups (GMFCS I/II and III). Transverse plane improvements were only seen for the FDO group (GMFCS I/II and III). The Gait Deviation Index, an overall index of kinematics, improved by a significantly greater amount for the FDO group across GMFCS levels I/II and III. Net oxygen cost improved for both FDO and No-FDO for GMFCS I/II. PODCI scores improved for FDO and No-FDO in GMFCS I/II, but only the FDO group for GMFCS III.

CONCLUSIONS

For children with CP, inclusion of an FDO in the surgical intervention, when indicated, resulted in improved outcomes. Overall gait kinematic improvements were significantly greater when an FDO was included in the surgical management.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Multilevel surgery in adults with cerebral palsy

Aims

Single-event multilevel surgery (SEMLS) has been used as an effective intervention in children with bilateral spastic cerebral palsy (BSCP) for 30 years. To date there is no evidence for SEMLS in adults with BSCP and the intervention remains focus of debate.

Methods

This study analysed the short-term outcome (mean 1.7 years, standard deviation 0.9) of 97 ambulatory adults with BSCP who performed three-dimensional gait analysis before and after SEMLS at one institution.

Results

Two objective gait variables were calculated pre- and post-operatively; the Gillette Gait Index (GGI) and the Gait Profile Score (GPS). The results were analysed in three groups according to their childhood surgical history (group 1 = no surgery, group 2 = surgery other than SEMLS, group 3 = SEMLS). Improvements in gait were shown by a significant decrease of GPS (p = 0.001). Similar results were obtained for both legs (GGI right side and left side p = 0.01). Furthermore, significant improvements were found in all subgroups although this was less marked in group 3, where patients had undergone previous SEMLS.

Discussion

SEMLS is an effective and safe procedure to improve gait in adults with cerebral palsy. However, a longer rehabilitation period is to be expected than found in children. SEMLS is still effective in adult patients who have undergone previous SEMLS in childhood. Take home message: Single-event multilevel surgery is a safe and effective procedure to improve gait disorders in adults with bilateral spastic cerebral palsy. Cite this article: Bone Joint J 2016;98-B:282–8.

Measuring physiological and pathological femoral anteversion using a biplanar low-dose X-ray system: validity, reliability, and discriminative ability in cerebral palsy

OBJECTIVE

The aims of this study were to evaluate the concurrent validity and reliability of a low-dose biplanar X-ray system (Ld-BPR) for the measurement of femoral anteversion (FA) by comparing Ld-BPR-based three-dimensional measures with CT-scan-based measures and to assess the discriminative ability of this method in children with cerebral palsy.

MATERIALS AND METHODS

Fifty dry femora were scanned using both a CT scan and the Ld-BPR system. Ten femora were artificially modified to mimic a range of anteversion from -30° to +60° and scanned by both modalities. FA was quantified using the images from both modalities and statistically compared for concurrent validity. Intra- and inter-observer reliability of the Ld-BPR system was also determined. Further, Ld-BPR data from 16 hemiplegic and 22 diplegic children were analyzed for its discriminative ability.

RESULTS

The concurrent validity between the Ld-BPR and CT-scan measures was excellent (R (2) = 0.83-0.84) and no significant differences were found. The intra- and inter-trial reliability were excellent (ICCs = 0.98 and 0.97) with limits of agreement of (-2.28°; +2.65°) and (-2.76°; +3.38°) respectively. Further, no significant effects of angle or method were found in the sample of modified femora. Ld-BPR measures for FA were significantly different between healthy and impaired femora.

CONCLUSIONS

The excellent concurrent validity with the CT scan modality, the excellent reliability, and the ability to discriminate pathological conditions evaluated by this study make this radiological method suitable for a validated use across hospitals and research institutes.

Factors associated with recurrence after femoral derotation osteotomy in cerebral palsy

Femoral derotation osteotomy (FDO) as gold standard treatment for internal rotation gait in cerebral palsy (CP) leads to satisfying short-term results, whereas rates of recurrence up to 33% are reported in long-term outcome studies. The purpose of this study was therefore to identify factors contributing to recurrence of internal rotation gait in patients with CP who were treated with FDO in childhood. 70 patients (age: 10 (± 3.3) years at surgery) with bilateral CP and internal rotation gait were examined pre-, one year and at least five years (mean 8 ± 2 years) postoperatively after distal or proximal FDO, using standardized clinical examination and 3D gait-analysis. 27 patients had a good hip rotation one year postoperatively (between 5° external and 15° internal for both limbs) and were considered for the analysis of factors contributing to recurrence of internal rotation gait. Regarding all included patients both mean hip rotation and foot progression angle improved significantly (p < 0.001) from pre- to postoperative. A significant deterioration in hip rotation (more involved side) (p < 0.001) from one year postoperatively to the long-term follow-up can be observed. Younger age, reduced hip joint impulse, increased plantar flexion and internal foot progression angle postoperatively could be identified as factors for recurrence. FDO on average leads to a satisfactory correction of internal rotation gait. In order to improve the long-term outcome after FDO the time of multilevel surgery should be indicated as late as possible and the different factors leading to potential recurrence should be considered.