Three-Dimensional Instrumented Gait Analysis for Children With Cerebral Palsy: An Evidence-Based Clinical Practice Guideline.

BACKGROUND: Children with cerebral palsy (CP) who walk have complex gait patterns and deviations often requiring physical therapy (PT)/medical/surgical interventions. Walking in children with CP can be assessed with 3-dimensional instrumented gait analysis (3D-IGA) providing kinematics (joint angles), kinetics (joint moments/powers), and muscle activity. PURPOSE: This clinical practice guideline provides PTs, physicians, and associated clinicians involved in the care of children with CP, with 7 action statements on when and how 3D-IGA can inform clinical assessments and potential interventions. It links the action statement grades with specific levels of evidence based on a critical appraisal of the literature. CONCLUSIONS: This clinical practice guideline addresses 3D-IGA's utility to inform surgical and non-surgical interventions, to identify gait deviations among segments/joints and planes and to evaluate the effectiveness of interventions. Best practice statements provide guidance for clinicians about the preferred characteristics of 3D-IGA laboratories including instrumentation, staffing, and reporting practices.Video Abstract: Supplemental digital content available at http://links.lww.com/PPT/A524.

Is peak hamstrings muscle-tendon length criterion a sufficient indicator to recommend against surgical lengthening of hamstrings?

BACKGROUND: Excessive knee flexion during stance in children with cerebral palsy is often treated by surgical hamstrings lengthening. Pre-operative hamstrings muscle-tendon length can be estimated from kinematics and often used for decision making to rule out surgical lengthening if peak hamstrings muscle-tendon length is 'Not Short'. RESEARCH QUESTION: If peak hamstrings muscle-tendon length is within two standard deviations of typical, is that a sufficient indicator to rule out surgical hamstrings lengthening? METHODS: Three motion analysis centers retrospectively identified children with cerebral palsy, age 6-17 years, who had consecutive gait analyses with knee flexion at initial contact > 20° and popliteal angle > 35° at initial study. Three groups were considered: Medial Hamstrings Lengthening (MHL), Medial and Lateral Hamstrings Lengthening (MLHL), no surgical intervention (Control). Peak hamstrings muscle-tendon length at initial gait study was computed and categorized as 'Short' or 'Not Short'. Two outcomes variables were considered: change in peak knee extension (PKE) and change in pelvic tilt. Univariate comparisons of all variables were assessed along with a multivariate stepwise regression analysis to identify pre-operative characteristics that may predict post-operative improvement. RESULTS: 440 individuals met inclusion criteria. Percentage of individuals with improved PKE by grouping were- MHL-'Short': 60%, MHL-'Not Short': 65%, MLHL-'Short': 74%, MLHL-'Not Short': 74%, Control 'Short': 20%, Control 'Not Short': 19%. Percentage of individuals with worsened pelvic tilt were- MHL-'Short': 25%, MHL-'Not Short': 11%, MLHL-'Short': 42%, MLHL-'Not Short': 21% with significantly more individuals in MHL-'Short' subgroup compared to MHL-'Not Short'. Multivariate analysis suggested that pre-operative pelvic tilt and weak hip extensor strength have the largest effect on predicting post-operative increase in APT. Peak muscle-tendon length was not a significant predictor of post-operative knee kinematics or increase in APT. SIGNIFICANCE: This study suggests that hamstrings muscle-tendon length criteria by itself is not a sufficient indicator to recommend against hamstrings lengthening.

The long-term effects of aggressive spasticity reducing treatment, including selective dorsal rhizotomy, on joint kinematic outcomes of persons with cerebral palsy.

BACKGROUND: Selective dorsal rhizotomy (SDR) creates a large and permanent reduction of spasticity for children with cerebral palsy (CP). Previous SDR outcomes studies have generally lacked appropriate control groups, had limited sample sizes, or reported short-term follow-up, limiting evidence for improvement in long-term gait function. RESEARCH QUESTION: Does aggressive spasticity management for individuals with CP improve long-term gait kinematics (discrete joint kinematics) compared to a control group of individuals with CP with minimal spasticity management? METHODS: This study was a secondary analysis - focused on joint-level kinematics - of a previous study evaluating the long-term outcomes of SDR. Two groups of participants were recruited based on a retrospectively completed baseline clinical gait study. One group received aggressive spasticity treatment including a selective dorsal rhizotomy (Yes-SDR group), while the other group had minimal spasticity management (No-SDR group). Both groups had orthopedic surgery treatment. Groups were matched on baseline spasticity. All participants prospectively returned for a follow-up gait study in young adulthood (greater than 21 years of age and at least 10 years after baseline). Change scores in discrete kinematic variables from baseline to follow-up were assessed using a linear model that included treatment arm (Yes-SDR, No-SDR), baseline age, and baseline kinematic value. For treatment arm, 5° and 5 Gait Deviation Index points were selected as thresholds to be considered a meaningful difference between treatment groups. RESULTS: At follow-up, there were no meaningful differences in pelvis, hip, knee, or ankle kinematic variable changes between treatment arms. Max knee flexion - swing showed a moderate treatment effect for Yes-SDR, although it did not reach the defined threshold. SIGNIFICANCE: Aggressive spasticity treatment does not result in meaningful differences in gait kinematics for persons with cerebral palsy in young adulthood compared to minimal spasticity management with both groups having orthopedic surgery.

Symmetry of Shoe Size and Calf Girth in Children With Treated Idiopathic Clubfoot: A Longitudinal Study.

BACKGROUND: Treatments for idiopathic clubfoot focus on obtaining a functional foot, typical gait pattern, and activity participation. Patients and families are also concerned about practical considerations regarding shoe wear and the appearance of the calf. The purpose of this study was to quantify whether children treated for idiopathic clubfoot have symmetry differences in shoe size and calf girth when presenting with unilateral versus bilateral involvement. METHODS: Participants with a diagnosis of idiopathic clubfoot (treated with Ponseti or French functional methods) were prospectively recruited along with children who are typically developing. Shoe size and calf girth were measured at 5, 7, and 10 years of age. RESULTS: Sixty-five participants, 45 with a diagnosis of idiopathic clubfoot (26 unilateral and 19 bilateral) and 20 who were typically developing, began the study at age 5. Children with clubfoot treated with the Ponseti versus French methods showed no differences in shoe size asymmetry, calf girth asymmetry, or absolute calf girth at age 5. Participants with unilateral clubfoot demonstrated an average of 1.5 size smaller shoes for the involved side at all 3 ages. Participants with bilateral clubfeet had a significantly smaller, <0.75 size difference between both feet. Participants with unilateral clubfoot demonstrated about a 2 cm smaller calf girth on the involved side compared with the uninvolved side at all 3 ages. Participants with bilateral clubfeet had a smaller, <0.5 cm calf difference between sides. Calf girths for involved limbs were significantly smaller than for uninvolved limbs. CONCLUSIONS: Children with unilateral clubfeet can expect to need a smaller shoe on their involved side. Children with bilateral clubfeet can expect a minimal shoe size discrepancy between limbs. All limbs with clubfoot involvement can expect to have a smaller calf girth than limbs that are typically developing. LEVEL OF EVIDENCE: Level II. This is considered a prognostic study-investigating the effect of a treated clubfoot on shoe size and calf girth. This is a lesser-quality prospective study in which <80% of persons completed follow-up.

Long-term effects of spasticity treatment, including selective dorsal rhizotomy, for individuals with cerebral palsy.

AIM: To understand the long-term effects of comprehensive spasticity treatment, including selective dorsal rhizotomy (SDR), on individuals with spastic cerebral palsy. METHOD: This was a pre-registered, multicenter, retrospectively matched cohort study. Children were matched on age range and spasticity at baseline. Children at one center underwent spasticity treatment including SDR (Yes-SDR, n=35) and antispastic injections. Children at two other centers had no SDR (No-SDR, n=40 total) and limited antispastic injections. All underwent subsequent orthopedic treatment. Participants returned for comprehensive long-term assessment (age ≥21y, follow-up ≥10y). Assessment included spasticity, contracture, bony alignment, strength, gait, walking energy, function, pain, stiffness, participation, and quality of life. RESULTS: Spasticity was effectively reduced at long-term assessment in the Yes-SDR group and was unchanged in the No-SDR group. There were no meaningful differences between the groups in any measure except the Gait Deviation Index (Yes-SDR + 11 vs No-SDR + 5) and walking speed (Yes-SDR unchanged, No-SDR declined 25%). The Yes-SDR group underwent more subsequent orthopedic surgery (11.9 vs 9.7 per individual) and antispastic injections to the lower limbs (14.4 vs <3, by design). INTERPRETATION: Untreated spasticity does not cause meaningful impairments in young adulthood at the level of pathophysiology, function, or quality of life.

Instrumented gait analysis for management of gait disorders in children with cerebral palsy: A scoping review.

BACKGROUND: The use of Instrumented Gait Analysis (IGA) for the clinical management of individuals with cerebral palsy (CP) has increased in recent years. Previous systematic reviews have been completed to evaluate and summarize the evidence related to the efficacy of IGA in general. However, a focused summary of research studies on IGA for children with CP related gait disorders is needed. RESEARCH QUESTION: The purpose of the current work was to perform a scoping review to describe and categorize the range of existing literature about IGA as applied to the clinical management of children with CP related gait disorders. METHOD: A health sciences librarian developed a search strategy to include four key inclusion criteria of original research study, population included children with CP, study employed IGA, available in English. The available literature was organized into six study categories: reliability and validity, documentation of subgroups or model development, IGA for clinical decision making, effectiveness of treatments that depend on IGA, cost effectiveness, IGA used to evaluate the outcome of surgical, medical or rehabilitation treatment. RESULTS: 909 studies met the inclusion criteria and were placed into the six study categories. 14 % of studies were in reliability and validity, 33 % in subgroups or modeling, 2% in IGA for clinical decision making, 2% in treatments that depend on IGA, 1% in cost effectiveness, and 49 % of studies had IGA used as an outcome measure for treatment. SIGNIFICANCE: This scoping review has documented the wide range, diversity and extent of original research studies investigating the use of IGA for the clinical management of children with CP related gait disorders. The large volume of studies provides a basis for future work to develop a CPG about the use of IGA for the clinical management of children with CP related gait disorders.

Children with Cerebral Palsy Have Similar Walking and Running Quality Assessed by an Overall Kinematic Index.

Running ability is critical to maintaining activity participation with peers. Children and adolescents with cerebral palsy (CP) are often stated to run better than they walk, but running is not often quantitatively measured. The purpose of this study was to utilize overall gait deviation indices to determine if children with diplegic CP run closer to typically developing children than they walk. This retrospective comparative study utilized 3D running kinematics that were collected after walking data at two clinical motion analysis centers for children with diplegic cerebral palsy. Separate walking and running Gait Deviation Indices (GDI Walk and GDI* Run), overall indices of multiple plane/joint motions, were calculated and scaled for each participant so that a typically developing mean was 100 with standard deviation of 10. An analysis of variance was used to compare the variables Activity (walking vs running) and Center (data collected at two different motion analysis laboratories). Fifty participants were included in the study. The main effect of Activity was not significant, mean GDI Walk = 76.4 while mean GDI* Run = 77.1, p = 0.84. Mean GDI scores for walking and running were equivalent, suggesting children with diplegic cerebral palsy as a group have similar walking and running quality. However, individual differences varied between activities, emphasizing the need for individual assessment considering specific goals related to running.

Synergies analysis produces consistent results between motion analysis laboratories.

AIM: The dynamic motor control index during walking (walk-DMC) is a scaled measure of motor control derived from electromyographic analysis of the lower extremity during gait. Walk-DMC has been shown to be related to patient outcomes and there has been an increasing interest from motion analysis centers regarding using this metric in their own practice. However, the methods for computing the index reported in the literature are not consistent. Here we propose a standardized method and investigate if this leads to results that are consistent between laboratories. METHOD: Comparisons between three sets of typically developing controls contributed by three independent motion analysis centers are made. Comparisons are also made between the proposed and previously published methods. A program script to compute the walk-DMC was used for this study and is made freely available with this manuscript. RESULTS: Using this script, results are highly consistent between three participating centers. The currently proposed method results in a wider distribution of walk-DMC values than those previously reported. INTERPRETATION: Using consistent processing methods, synergy measures are equivalent between centers. The major differences between current and published data are attributed to the use of concatenation of several walking trials.

Factors Influencing Outcomes of the Dysplastic Hip in Nonambulatory Children With Cerebral Palsy.

BACKGROUND: Hip dysplasia in the nonambulatory child with spastic cerebral palsy (CP) is a common condition not always effectively treated with conservative measures even when recognized early. Optimal surgical intervention strategies and timing are not clear from previous studies. Contralateral hips with less severe subluxation in these patients also often undergo surgery and little is known of outcomes of these less severe hips. This study aims to clarify treatment factors related to long term success following hip surgery for subluxation in nonambulatory children with CP. METHODS: A total of 183 nonambulatory subjects with CP and a minimum of 2-year follow-up were included. All subjects underwent varus rotational osteotomy of the femur; other surgical factors considered were addition of pelvic osteotomy (PO), capsulorrhaphy, and soft tissue releases. Additional factors studied were age at index surgery, sex, and unilateral versus bilateral surgery. Severely subluxated (SS) hips, defined as having >50% migration, were studied separately from contralateral nonsevere hips. Surgeries were deemed successful if final follow-up indicated a migration of <25%; patients with any revision surgeries or >25% migration were categorized as failures. RESULTS: A 60% success rate was found in SS hips and a 68% success rate in nonsevere hips. Age at index surgery did not influence success rates in SS hips. In the nonsevere hips, success was associated with index surgery at older age. The addition of a PO was the only concomitant procedure demonstrated to improve outcomes. In SS hips, those with a successful outcome were 2.5 times more likely to have had a PO. The addition of capsulorrhaphy had a negative effect on the entire group, reducing odds of success to 0.8. No other factors were significant. CONCLUSIONS: The findings from this multicenter retrospective study suggest that PO be added to varus rotational osteotomies in patients with severe hip subluxation. Surgery should be undertaken for severe dysplasia without concern for age. The addition of capsulorrhaphy does not improve rate of success. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Early Bony Hip Reconstructive Surgery for Hip Subluxation in Children With Severe Cerebral Palsy.

Hip subluxation occurs frequently in children with severe cerebral palsy. This retrospective study examined the effects of age and type of bony surgery on radiographic outcomes of children with severe cerebral palsy who were treated for hip subluxation. The study included nonambulatory children with cerebral palsy undergoing bony hip reconstructive surgery consisting of proximal femoral varus derotational osteotomy (VDRO) alone or combined with pelvic osteotomy. The migration index was recorded for preoperative, postoperative, and final follow-up (minimum 2 years) radiographs. Failure was defined as subsequent bony hip reconstructive surgery or final follow-up migration index greater than 50%. Seventy-seven hips in 40 patients younger than 6 years (55 VDRO alone, 22 combined) and 73 hips in 43 patients older than 6 years (27 VDRO alone, 46 combined) met inclusion criteria. For VDRO alone, the failure rate for patients younger than 6 years (33%) was significantly higher than for patients older than 6 years (7%). For combined procedures, failure rates between younger (0%) and older groups (9%) were not significantly different. Patients younger than 6 years undergoing combined procedures started with a significantly worse migration index than patients undergoing VDRO alone, 72% vs 46%, yet had significantly better final migration indices of 13% vs 31%, respectively. For surgeons performing bony reconstructive surgery to treat hip subluxation in younger children with severe cerebral palsy who are nonambulatory, the findings of this study support the use of combined VDRO and pelvic osteotomy. [Orthopedics. 2021;44(2):e294-e300.].

Comparing the effects of two spasticity management strategies on the long-term outcomes of individuals with bilateral spastic cerebral palsy: a multicentre cohort study protocol.

INTRODUCTION: Spasticity is one of the primary pathologies associated with cerebral palsy (CP), yet no definitive evidence exists to guide the appropriate level of spasticity management for an individual. Spasticity management strategies often differ by center. On one end of this strategy spectrum is a highly-interventional approach, characterized by treatments such as a selective dorsal rhizotomy (SDR), intrathecal baclofen pump (ITB), and anti-spasticity injections and medications. On the other end of the spectrum is a less interventional approach, involving minimal use of these treatments, and no SDR. METHODS AND ANALYSIS: A retrospectively-matched, multi-center study protocol is described that comprehensively compares the long-term outcomes of a highly-interventional versus a minimally-interventional spasticity management strategy. We will analyze two groups of adults with spastic bilateral CP (≥21 years). In one group are individuals who underwent an SDR between the ages of 4 and 10 years, along with ongoing spasticity management during childhood and adolescence. In the other group are individuals who received minimal spasticity management and did not undergo an SDR. Individuals with prolonged use of an intrathecal baclofen (ITB) pump will be excluded. The two groups will be matched for spasticity and other important clinical characteristics at baseline. This study design improves on many of the limitations found in the existing outcome literature. ETHICS AND DISSEMINATION: This study received necessary approval from the University of Minnesota and Western Institutional Review Boards. Results will be disseminated via peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT03789786.

Secondary Surgery Rates After Primary Fusion for Adolescent Idiopathic Scoliosis.

Instrumented spinal fusion is the gold standard treatment for surgical magnitude adolescent idiopathic scoliosis (AIS), with the goal being stable fusion without the need for additional procedures. The purpose of this study was to define the surgical return rates of AIS at a single center with respect to various instrumentation constructs used during initial spinal fusion. A retrospective chart review was performed of all patients with AIS who underwent instrumented fusion with a minimum of 2-year follow-up. Demographic information, implant type, and surgical approach for the primary surgery and all subsequent secondary operations were recorded. Four hundred eleven patients who underwent instrumented fusion for AIS during the study period met inclusion criteria. Sixty-six secondary operations were performed in 50 patients (12.2%). Symptomatic hardware, pseudarthrosis, and infection were the most common indications for secondary surgery. Posterior pedicle screw constructs had a lower secondary surgery rate (5.8%) compared with hybrid and combined fusions (P<.05). The all hook, hybrid, anterior only, and combined fusions had secondary surgery rates of 13.0%, 18.5%, 10.0%, and 20.8%, respectively, which were not statistically different. When specifically comparing pedicle screw with hook constructs, there was a statistically lower pseudarthrosis rate (P=.03) favoring pedicle screw instrumentation. Patients undergoing instrumented fusion for AIS are at some risk for subsequent surgery. To lessen that risk, pedicle screw constructs should be considered, as they have shown an overall lower secondary surgery rate and in particular a lower rate of pseudarthrosis. [Orthopedics. 2019; 42(4):235-239.].

Quantitative coronal plane motion of hindfoot during clinical flexibility assessments.

BACKGROUND: Common pediatric pathologic foot presentations include cavovarus and planovalgus feet. Flexibility of the hindfoot is established for these two clinical presentations through the Coleman block (eversion) and tiptoe tests (inversion). RESEARCH QUESTION: The purposes of this study are to establish typical quantitative eversion and inversion motion of the hindfoot during Coleman block and tiptoe tests using 3-D motion capture and demonstrate feasibility of using this data to assist in making treatment decisions. METHODS: Segmented foot model kinematics were collected for this prospective descriptive study with a focus on coronal plane inversion and eversion of the hindfoot relative to the tibia. Typical standing hindfoot position, with the feet plantigrade, was determined prior to performing the tiptoe test. Maximum hindfoot inversion was extracted from the tiptoe test. Maximum hindfoot eversion was extracted from the Coleman block tests. RESULTS: 32 typically developing subjects (age range 5-21 years) completed this study. Hindfoot motion data showed a mean standing foot position of 1 ° eversion, 10 degrees inversion during tiptoe test and 6 degrees eversion during the Coleman block test. SIGNIFICANCE: Establishing control values for hindfoot flexibility can assist with making clinical treatment decisions for disorders of the foot. At our center, clients who present to the Motion Analysis Center with foot concerns receive segmented foot model quantitative assessment of hindfoot flexibility with Coleman block and tiptoe tests as appropriate.

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.

Long term gait outcomes of surgically treated idiopathic toe walkers.

Toe walking is a common gait deviation which in the absence of a known cause is termed idiopathic toe walking. Surgical treatment in the presence of a triceps surae contracture includes tendo-Achilles or gastrocnemius/soleus recession and has been shown to be effective in improving kinematic outcomes at a one year follow up. The purpose of this study was to assess longer term kinematic and kinetic outcomes of children with idiopathic toe walking treated surgically for gastrocnemius/soleus contractures. Eight subjects with a diagnosis of idiopathic toe walking who had surgical lengthening of the gastrocnemius/soleus and had previous motion analysis laboratory studies pre-operative and 1 year post-operative, returned for a motion analysis laboratory study greater than 5 years since surgery. Subjects completed lower extremity physical exam and 3-D computerized kinematics and kinetics. Significant improvements for mean pelvic tilt, peak dorsiflexion in stance and swing, and overall kinematics index at 1 year post-operative were maintained at 5 years post-operative. Kinetic variables of ankle moment and power were improved at 1 year and 5 years post-operative. On physical exam, dorsiflexion with knee extended was tighter from 1 to 5 year follow-up which did not correspond to the functional changes of gait. Idiopathic toe walkers who were treated surgically for triceps surae contractures showed significant improvements in key kinematic and kinetic gait analysis variables at 1 year post-operative that were maintained at 5 years post-operative. Overall, subjects were satisfied with outcomes of the surgery, unrestricted in activities, and reported minimal pain.

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.

Application of the Gillette Gait Index, Gait Deviation Index and Gait Profile Score to multiple clinical pediatric populations.

Gait indices are now commonly used to assess overall pathology and outcomes from studies with instrumented gait analyses. There are differences in how these indices are calculated and therefore inherent differences in their sensitivities to detect changes or differences between groups. The purpose of the current study was to examine the three most commonly used gait indices, Gillette Gait Index (GGI), Gait Deviation Index (GDI), and Gait Profile Score (GPS), comparing the statistical sensitivity and the ability to make meaningful interpretations of the clinical results. In addition, the GDI*, a log transformed and scaled version of the GPS score which closely matches the GDI was examined. For seven previous or ongoing studies representing varying gait pathologies seen in clinical laboratories, the GGI, GDI, and GPS/GDI* were calculated retrospectively. The GDI and GPS/GDI* proved to be the most sensitive measures in assessing differences pre/post-treatment or from a control population. A power analysis revealed the GDI and GDI* to be the most sensitive statistical measures (lowest sample sizes required). Subjectively, the GDI and GDI* interpretation seemed to be the most intuitive measure for assessing clinical changes. However, the gait variable sub-scores of the GPS determined several statistical differences which were not previously noted and was the only index tool for quantifying the relative contributions of specific joints or planes of motion. The GGI did not offer any advantages over the other two indices.

Gait outcomes of patients with severe slipped capital femoral epiphysis after treatment by flexion-rotation osteotomy.

BACKGROUND: Flexion-rotational osteotomy of the proximal femur is an accepted intervention in the management of severe deformity and femoral acetabular impingement secondary to slipped capital femoral epiphysis (SCFE). The impact of this surgical intervention on gait kinematics and kinetics, validated functional questionnaires, and patient outcomes has not been well studied. The purpose of this study was to analyze the changes in standard gait parameters of patients with moderate to severe SCFE who were treated with a flexion-rotational osteotomy. METHODS: This study is a retrospective review of 8 patients treated for a unilateral moderate and severe SCFE with a flexion-rotational osteotomy. All patients had 3-D computerized gait analysis studies completed preoperatively and 1-year postoperatively. Additional data analyzed preoperatively and postoperatively included: anterior/posterior hip radiographs, standard physical examination measures, and Pediatric Outcomes Data Collection Instrument (PODCI), completed by parents. RESULTS: The Gait Deviation Index, a composite of gait kinematics, showed a significant improvement from 64.9 to 88.0 (P<0.001). Radiographically, significant improvement toward normal values were found in the epiphyseal-shaft angle on the AP view from 123 to 139 degrees (P=0.005) and on the frog lateral view from 61 to 16 degrees (P=0.00001). Hip abduction range of motion on physical examination increased from 15 to 27 degrees and hip external rotation decreased from 51 to 25 degrees after surgery (P<0.05). The PODCI significantly improved in the categories of basic mobility, sports function, and global function (P<0.05). CONCLUSIONS: Longstanding deformity as a result of a severe SCFE may lead to osteoarthritis of the hip, disabling pain, and functional deficits. Although radiographic evidence of degenerative disease may take years to develop, changes in gait parameters can be immediately evident in this population. A flexion-rotation osteotomy in the adolescent and young adult population can improve gait kinematics, radiographic measures, range of motion, and short-term functional outcome scores. It is felt that normalization of these parameters may reduce the risk of long-term hip deterioration and its related sequelae. LEVEL OF EVIDENCE: Level IV.