Treatment of fixed knee flexion deformity and crouch gait using distal femur extension osteotomy in cerebral palsy

Purpose

The purpose of this study was to evaluate the results of distal femur extension osteotomy and medial hamstring lengthening in the treatment of fixed knee flexion deformity in patients with spastic diparetic cerebral palsy.

Methods

A retrospective study was done in a group of 12 diparetic cerebral palsy patients. A distal femur extension osteotomy was performed as part of multilevel surgery on lower limbs. The fixed knee flexion deformity was measured during physical examination, whereas hip and knee flexion in the stance phase and anterior pelvic tilt were both analyzed at kinematics. The pre- and post-surgery results were compared and analyzed statistically. A medical record review was done in order to identify the complications. The mean follow-up was 28 months.

Results

A significant reduction of fixed knee flexion deformity at physical examination and knee flexion in the stance phase at kinematics was observed, but with no decrease in hip flexion. As a non-desired effect, there was an increase in anterior pelvic tilt after surgical procedures. With regard to complications, a single patient had skin breakdown at a calcaneous area on one side and the recurrence of deformity was seen in 27% of cases.

Conclusions

In this study, in which fixed knee flexion deformity did not exceed 40° before surgery, the distal femur extension osteotomy was effective in increasing knee extension in the stance phase. However, an increase in anterior pelvic tilt, deformity recurrence and necessity for walking aids are possible complications of this procedure.     

A functional electrical stimulation system improves knee control in crouch gait

BackgroundCrouch gait is a major sagittal plane deviation in children diagnosed with cerebral palsy (CP). It is defined as a combination of excessive ankle dorsiflexion and knee and hip flexion throughout the stance phase. To the best of our knowledge, functional electrical stimulation (FES) has not been used to decrease the severity of crouch gait in CP subjects and assist in achieving lower limb extension.PurposeTo evaluate the short- and long-term effects of FES to the quadriceps muscles in preventing crouch gait and achieving ankle plantar flexion, knee and hip extension at the stance phase.MethodsAn 18-year-old boy diagnosed with CP diplegia [Gross Motor Function Classification System (GMFCS) level II] was evaluated. The NESS L300^® Plus neuroprosthesis system provided electrical stimulation of the quadriceps muscle. A three-dimensional gait analysis was performed using an eight-camera system measuring gait kinematics and spatiotemporal parameters while the subject walked shod only, with ground reaction ankle foot orthotics (GRAFOs) and using an FES device.ResultsWalking with the FES device showed an increase in the patient’s knee extension at midstance and increased knee maximal extension at the stance phase. In addition, the patient was able to ascend and descend stairs with a “step-through” pattern immediately after adjusting the FES device.ConclusionsThis report suggests that FES to the quadriceps muscles may affect knee extension at stance and decrease crouch gait, depending on the adequate passive range of motion of the hip, knee extension, and plantar flexion. Further studies are needed in order to validate these results.     

Postoperative gait velocity and mean knee flexion in stance of ambulatory children with spastic diplegia four years or more after multilevel surgery

Factors associated with longer-term outcomes of multilevel orthopaedic surgery in ambulatory children with cerebral palsy using a multivariate approach were evaluated using a retrospective pretest-posttest design. The population included 20 ambulatory children with spastic diplegia who had undergone multilevel orthopaedic surgery with a minimum of 4-year interval between a preoperative and a postoperative gait assessment. Multiple regression analysis was used to identify factors associated with postoperative velocity and mean knee flexion in stance. Independent variables included in the regression models were velocity, mean knee flexion in stance, age at preoperative evaluation, Gross Motor Function Classification System level, use of ankle-foot orthoses, leg length, age-adjusted body mass index, number of surgical procedures, and range of motion of hip and knee. Children who demonstrated faster postoperative gait velocity 4 years or more after surgery were younger at the time of initial evaluation, had undergone fewer surgical procedures, had faster preoperative gait velocity, used ankle-foot orthoses postoperatively, and had increased hip extension range of motion postoperatively (R = 0.55). Children who demonstrated greater knee flexion in stance 4 years or more after surgery had undergone more surgical procedures, greater postoperative popliteal angle, and less knee extension range of motion (R = 0.73). This study demonstrates the usefulness of a multivariate approach toward understanding and predicting outcomes. The results of this study will provide clinicians and researchers more information about those factors associated with maintained improvements in the longer term and may be useful for treatment planning.     

Significance of static prosthesis alignment for standing and walking of patients with lower limb amputation

The influence of three alignment parameters of a transtibial prosthesis (sagittal foot position, plantar flexion, mediolateral foot position) on the load and motion of the lower extremity joints was investigated in 13 unilateral transtibial amputees. The aim was to determine whether a correlation exists between static prosthetic alignment and gait pattern that would allow an optimal biomechanical prosthetic alignment. The gait pattern was measured using kinematic, kinetic, and electromyographic methods. Statics was defined using the alignment apparatus L.A.S.A.R. Posture. The electromyogram of the m. vastus lateralis and m. biceps femoris was recorded on both sides. The motion of joints is described by joint angles. External joint moments define the mechanical loads. Alignment has almost no influence on muscle activity and joint mechanics of the contralateral leg. In contrast, prosthetic alignment affects clearly and systematically the load and motion of the knee joint during the stance phase on the ipsilateral side. The sagittal foot position influences the maximal flexion angle in the stance phase. The plantar flexion of the foot affects the temporal structure of knee motion. The mediolateral foot position causes correspondingly different varus and valgus moments acting on the knee. Swing phase motion does not depend on prosthetic alignment. The iEMG of the m. vastus lateralis is reduced. Innervation characteristics of the m. biceps femoris on the prosthetically fitted leg has completely changed. The ischiocrural muscles take over the neuromuscular action of the m. gastrocnemius to compensate for the external knee extension moment during the second part of the stance phase. Prosthetic statics determines if the knee joint is physiologically stressed in a standing posture and during walking. Statics will be correct if the anatomical knee axis of the standing amputee is located about 15 mm posterior to the load line in the sagittal plane. In the frontal plane, the load line touches the lateral patella border and strikes the middle of the foot about 5 cm anterior to the adapter. During walking, attention should be paid to performance of knee flexion in the stance phase.     

The effect of tuning ankle foot orthoses-footwear combinations on gait kinematics of children with cerebral palsy: A case series

Study designCase series.BackgroundAFOs are a commonly prescribed medical device given to children with cerebral palsy (CP) in an attempt to improve their gait. The current literature is equivocal on the effects AFOs have on the gait of children with CP. The vast majority of AFOs issued are not subject to AFO-FC tuning. There are emerging studies investigating the effects tuning AFO-FCs has on the gait of children with CP. However, the research is limited, and there is a lack of quantitative data.ObjectiveTo compare the kinematics of tuned versus non-tuned gait in children with CP.MethodsGait analysis assessment of five children aged between 7–11 years with a diagnosis of CP (one hemiplegic and four diplegic participants, two female, three male, with a Gross Motor Functional Classification System (GMFCS) of 2) at a Gait Analysis Laboratory.ResultsIn comparison to barefoot and non-tuned gait, walking with a tuned AFO-FC produced improvements in several key gait parameters. Including hip flexion and extension, posterior pelvic tilt and knee extension. Results also indicated that the type of gait pattern demonstrated by the participant affected the outcomes of tuning.ConclusionsTuning the AFO-FC of children with CP has the potential to improve hip function, pelvic function, knee extension in stance phase and knee flexion during swing phase and that a non-tuned AFO-FC can potentially decrease hip function, posterior pelvic tilt and increase knee extension.Clinical RelevanceWhilst AFO-FC tuning has been recommended for routine clinical practice, there still remains a paucity of research on the kinematic effects of using a tuned AFO-FC compared to a non-tuned. This paper provides a comparison of kinematics on children with CP, during barefoot, non-tuned and tuned AFO-FC walking with a view to inform clinical practice.     

Rectus femoris transfer for children with cerebral palsy: long-term outcome

The purpose of this study was to evaluate the long-term results of rectus femoris transfer in cerebral palsy children with stiff-knee gait. Thirty-eight affected limbs in 24 children were evaluated preoperatively and 1 year postoperatively by gait analysis, with 26 limbs in 18 patients having final study, averaging 4.6 years postoperatively. Functional ambulatory status was evaluated based on Hoffer's criteria on ambulation. There were statistically significant improvements of 9.8 degrees in maximum swing-phase knee flexion and 7.0 degrees in total range of knee motion at 1 year, with a small loss of knee extension in stance. At final gait analysis, the improvement in the swing-phase knee flexion was maintained, but improvement in total range of knee motion was decreased. There were no significant changes in temporal parameters. Improvement in swing-phase knee flexion and foot clearance after rectus femoris transfer was associated with loss of knee extension at long-term follow-up. Hamstring lengthening in patients who develop excessive stance-phase knee flexion may be necessary.     

Gait analysis of spastic walking in patients with cervical compressive myelopathy

To assess neurological status and to evaluate the effect of surgical decompression in patients with cervical myelopathy, we performed computerized gait analysis in 24 patients with cervical compressive myelopathy who showed spastic walking. Gait analysis was repeated during neurological follow-up that averaged 32.4 months. The gait pattern in patients with severe myelopathy was characterized by hyperextension of the knee in the stance phase without plantar flexion of the ankle in the swing phase, significantly reduced walking speed and step length, prolonged stance phase duration and decreased single-stance phase duration, and increased step width. The angle of flexion of the knee joint in the stance phase was significantly correlated with the Japanese Orthopaedic Association (JOA) score. Postoperative neurological improvement was associated with increased walking speed and decreased extension angle of the knee joint (single-stance phase and swing phase). Postoperatively, 12 patients had normalized extension of the knee in stance phase and their walking speed, cadence, stance phase duration, and single-stance phase duration, as well as step length and width, showed nonsignificant differences from these parameters in healthy controls. Our results show that kinesiological gait analysis is clinically useful for the functional assessment of the severity of spastic walking in cervical myelopathy.     

Ankle and knee coupling in patients with spastic diplegia: effects of gastrocnemius-soleus lengthening

BACKGROUND: Empirical observations of subjects with an equinus gait have suggested that there is coupled motion between the ankle and knee such that, during single-limb stance, the ankle moves into equinus as the knee extends. Since the gastrocnemius-soleus muscle-tendon unit spans both joints, we hypothesized that this muscle-tendon unit may be responsible for the coupling and that lengthening of the gastrocnemius-soleus muscle alone would result in greater ankle dorsiflexion as well as greater knee extension in single-limb stance, effectively uncoupling these joints. The concept that gastrocnemius-soleus lengthening may promote knee extension is counter to the popular notion that crouch gait may result if the hamstrings are not lengthened concomitantly. METHODS: A retrospective review identified thirty-four subjects with specific kinematic characteristics of equinus gait, and their gait was compared with that of normal children. Of the thirty-four subjects, eleven (twenty-two limbs) subsequently underwent isolated midcalf lengthening of the gastrocnemius and soleus muscles with use of a recession technique. Gait analysis including joint kinematics and joint kinetics, electromyography, and physical examination were performed to test the hypothesis. RESULTS: We found that, unlike the normal subjects, the patients with an equinus gait pattern had a positive correlation (r = 0.7) between ankle and knee motion during single-limb stance. As hypothesized, ankle plantar flexion occurred while the knee moved into extension during single-limb stance. Calculations of the lengths of the gastrocnemius-soleus muscle-tendon units showed them to be short throughout the gait cycle (p < 0.0001). After gastrocnemius-soleus recession, peak ankle dorsiflexion (p < 0.001) and peak ankle power (p < 0.001) shifted to occur later in stance than they did in the preoperative gait cycle. Furthermore, the magnitude of peak power increased (p < 0.001) in late stance despite the added length of the gastrocnemius-soleus muscle-tendon unit. The electromyographic amplitude of the gastrocnemius-soleus was reduced during loading (p < 0.02), and this finding, together with the kinetic changes, suggested that muscle tension was reduced. Changes at the knee were less pronounced but included greater knee extension at foot contact (p < 0.01). No increase in the knee flexion angle or extension moment occurred in midstance after the surgery. CONCLUSIONS: Patients with an equinus gait pattern function with a shortened gastrocnemius-soleus muscle-tendon unit, and this results in coupled motion between the ankle and knee during single-limb stance. Lengthening, with use of a recession technique, shifted ankle power generation and dorsiflexion to a later time in stance with no tendency to increase midstance knee flexion. Knee extension did increase at foot contact, but excessive midstance knee flexion persisted and was likely due to concomitant contracture of the hamstrings.     

Gait abnormalities following slipped capital femoral epiphysis

The authors evaluated 30 subjects with treated unilateral slipped capital femoral epiphysis and a range of severity from mild to severe to characterize gait and strength abnormalities using instrumented three-dimensional gait analysis and isokinetic muscle testing. For slip angles less than 30 degrees, kinematic, kinetic, and strength variables were not significantly different from age- and weight-matched controls. For moderate to severe slips, as slip angle increased, passive hip flexion, hip abduction, and internal rotation in the flexed and extended positions decreased significantly. Persistent pelvic obliquity, medial lateral trunk sway, and trunk obliquity in stance increased, as did extension, adduction, and external rotation during gait. Gait velocity and step length decreased with increased amount of time spent in double limb stance. Hip abductor moment, hip extension moment, knee flexion moment, and ankle dorsiflexion moment were all decreased on the involved side. Hip and knee strength also decreased with increasing slip severity. All of these changes were present on the affected and to a lesser degree the unaffected side. Body center of mass translation or pelvic obliquity in mid-stance greater than one standard deviation above normal correlated well with the impression of compensated or uncompensated Trendelenburg gait.     

Using real‐time MRI to quantify altered joint kinematics in subjects with patellofemoral pain and to evaluate the effects of a patellar brace or sleeve on joint motion

Abnormal patellofemoral joint motion is a possible cause of patellofemoral pain, and patellar braces are thought to alleviate pain by restoring normal joint kinematics. We evaluated whether females with patellofemoral pain exhibit abnormal patellofemoral joint kinematics during dynamic, weight‐bearing knee extension and assessed the effects of knee braces on patellofemoral motion. Real‐time magnetic resonance (MR) images of the patellofemoral joints of 36 female volunteers (13 pain‐free controls, 23 patellofemoral pain) were acquired during weight‐bearing knee extension. Pain subjects were also imaged while wearing a patellar‐stabilizing brace and a patellar sleeve. We measured axial‐plane kinematics from the images. Females with patellofemoral pain exhibited increased lateral translation of the patella for knee flexion angles between 0°and 50° (p = 0.03), and increased lateral tilt for knee flexion angles between 0° and 20° (p = 0.04). The brace and sleeve reduced the lateral translation of the patella; however, the brace reduced lateral displacement more than the sleeve (p = 0.006). The brace reduced patellar tilt near full extension (p = 0.001), while the sleeve had no effect on patellar tilt. Our results indicate that some subjects with patellofemoral pain exhibit abnormal weight‐bearing joint kinematics and that braces may be effective in reducing patellar maltracking in these subjects. Published by Wiley Periodicals, Inc. J Orthop Res 27: 571–577, 2009     

Vicon运动捕捉系统对单侧膝关节置换术后双侧膝关节生物力学的评价

目的探讨双侧膝关节骨关节炎患者单侧膝关节置换术后膝关节生物力学情况。方法应用Vicon运动捕捉系统采集30例双侧膝关节骨关节炎单侧膝关节置换术后行走数据,比较手术侧与非手术侧膝关节生物力学差异。结果手术侧与非手术侧膝关节生物力学存在明显差异。手术侧矢状面膝关节最大屈曲度、最大伸展度及最大活动范围较未手术侧增大(P<0.05);手术侧冠状面膝关节最大内翻度较未手术侧减小(P<0.05),手术侧冠状面膝关节最大外翻度较未手术侧增大(P<0.05);手术侧膝关节角速度和角加速度较未手术侧增快(P<0.05);手术侧膝关节屈曲力矩峰值较未手术侧增大(P<0.05),手术侧膝关节伸展力矩峰值较未手术侧减小(P<0.05);手术侧膝关节前后方向和垂直方向受力较未手术侧增大(P<0.05),手术侧膝关节左右方向受力较未手术侧减小(P<0.05)。结论采用Vicon运动捕捉系统对单侧膝关节置换术患者进行双侧膝关节生物力学评价可以准确地判断手术疗效和预测非手术侧手术时机。     

The study and correction of human gait by electrical stimulation

To gain a better understanding of the functions that the calf and vastus muscles perform in the human walking gait the author systematically increased the contractions of these muscles separately and in combination by applying Functional Electrical Stimulation (FES) to them, during walking tests performed by a subject with nonpathological gait, and a patient with a hemiplegic gait. A four-channel stimulator was used with foot switch activated control systems, which accurately sequenced the FES pulses and timed them in relation to the footswitch contacts. In normal gait FES applied to the calf muscles in the first third of the stance phase induced knee extension, but when applied later in the stance phase it increased the amount of plantar flexion and knee flexion at the push off. Strengthened vastus muscle contraction increased the amount and duration of stance phase knee extension, and interacted with the calf FES to increase the amount of heel rise at the push off. In the hemiplegic gait calf FES resulted in some increased knee flexion and ankle plantar flexion after the opposite heel strike, but a persistent lower limb extensor synergy prevented knee flexion from occurring simultaneously with plantar flexion and a heel rise, while the hemiplegic limb was still weight bearing.     

Outcome of hamstring lengthening and distal rectus femoris transfer surgery

To evaluate the outcome of hamstring lengthening and distal rectus femoris transfer, a retrospective study was performed comparing preoperative and postoperative gait analysis data from 16 children with neurologic involvement. Postoperatively, the timing of peak knee flexion during swing and the total arc of knee motion significantly improved. Hamstring range of motion and knee extension at terminal swing significantly improved, but stride length and gait velocity did not for the overall population. Patients who used braces postoperatively showed an improvement in stride length and velocity when wearing orthoses. This suggests that postoperative bracing may be needed in some patients to maximize the surgical outcome.     

Effect of hand position on knee extension and knee flexion torques of intercollegiate rowers

The purpose of this study was to determine if hand position: 1) grasping the test table and 2) grasping the pelvic strap, combined with stabilization via pelvic and distal thigh straps, affected knee extension and flexion torques of intercollegiate athletes. Eighteen male rowers (sweep oarsmen) completed three reciprocal contraction cycles using a 160 degrees /sec knee extension, 0.25 sec pause, and 80 degrees /sec knee flexion protocol. This protocol simulated the knee movements during rowing at about 27 strokes per minute. The order of presenting the hand positions was randomly assigned and a dependent t-test was used to compare hand positions. No statistically significant difference (p > 0.05) was observed between the peak torques produced when grasping the test table and when grasping the pelvic strap, during either knee extension (203 +/- 29 Nm and 207 +/- 26 Nm, respectively) or knee flexion (145 +/- 15 Nm and 149 +/- 18 Nm, respectively). When the knee extensors and flexors of relatively strong individuals are tested in the sitting position and while using a pelvic strap to secure the pelvis to the test table, the subjects may be given the option of grasping either the test table or the pelvic strap without significantly affecting their subsequent knee extension or flexion torques. J Orthop Sports Phys Ther 1990;11(8):367-371.     

The Effect of Total Knee Arthroplasty on Knee Joint Kinematics and Kinetics During Gait

This study determined how total knee arthroplasty (TKA) altered knee motion and loading during gait. Three-dimensional kinematic and kinetic gait patterns of 42 patients with severe knee osteoarthritis were collected 1 week prior and 1-year post-TKA. Principal component analysis extracted major patterns of variability in the gait waveforms. Overall and midstance knee adduction moment magnitude decreased. Overall knee flexion angle magnitude increased due to an increase during swing. Increases in the early stance knee flexion moment and late stance knee extension moment were found, indicating improved impact attenuation and function. A decrease in the early stance knee external rotation moment indicated alteration in the typical rotation mechanism. Most changes moved toward an asymptomatic pattern and would be considered improvements in motion, function, and loading.     

Disarticulation of the knee in children. A functional assessment

We assessed the functional abilities of six patients who had had disarticulation of nine knees during childhood by analyzing their gait using electrocardiographic telemetry. Those who were more than five years old were further studied by timing them as they ran the fifty-yard (45.7-meter) dash and by testing the strength of the musculature of the hip girdle using a Cybex dynamometer. The physiological cost-index of Butler et al. was used to assess energy consumption. Three patients had had unilateral disarticulation and three had had bilateral disarticulation. Kinematic studies showed persistent bilateral abduction of the hip throughout the gait cycle in all six patients. The flexion-extension arc of the hip was decreased in the three who had had bilateral disarticulation. Increased flexion of the hip was noted on the normal side and decreased flexion, on the affected side in those who had had unilateral disarticulation. Phase reversal of pelvic obliquity was noted in the amputees who had had bilateral disarticulation. The prosthetic knee showed good flexion during the swing phase. All patients showed a mild decrease in the velocity of gait and in the length of step and stride. The patients who had had unilateral disarticulation showed decreased duration of the bilateral stance and single stance phases and increased duration of the swing phase. Those who had had bilateral disarticulation of the knee had a normal distribution of the components of the gait cycle: bilateral stance, single stance, and swing. The physiological cost-index for all six was within the normal range, indicating minimum energy handicap.(ABSTRACT TRUNCATED AT 250 WORDS)     

Patellar biomechanics

The patella is an important functional component of the knee extension mechanism. It accounts for 13 to 30% of the knee extensors' moment arm. Functional deficits owing to patellectomy include decreased knee extension power, extension lag, instability, chronic effusion, decreased stance phase flexion, alteration of the path of instant flexion centers and decreased flexion range.     

Hamstrings and psoas lengths during normal and crouch gait: Implications for muscle-tendon surgery

Crouch gait, one of the most common movement abnormalities among children with cerebral palsy, is characterized by persistent flexion of the knee during the stance phase. Short hamstrings are thought to be the cause of crouch gait; thus, crouch gait is often treated by surgical lengthening of the hamstrings. In this study, a graphics-based model of the lower extremity was used in conjunction with three-dimensional kinematic data obtained from gait analysis to estimate the lengths of the hamstrings and psoas muscles during normal and crouch gaits. Only three of 14 subjects with crouch gait (four of 20 limbs with knee flexion of 20° or more through stance) had hamstrings that were shorter than normal by more than 1 SD during walking. Most (80%) of the subjects with crouch gait had hamstrings of normal length or longer, despite persistent knee flexion during stance. This occurred because the excessive knee flexion was typically accompanied by excessive hip flexion throughout the gait cycle. All of the subjects with crouch gait had a psoas that was shorter than normal by more than 1 SD during walking. These results emphasize the need to consider the geometry and kinematics of multiple joints before performing surgical procedures aimed at correcting crouch gait.     

Gait anlysis in patients with osteoarthritis of the knee before and after total knee replacement

AIM: The reduction in quadriceps femoris muscle activation is considered to be one of the major mechanisms involved in pathological motion patterns in patients with osteoarthritis (OA) of the knee. These activation deficits are, at least in part, reversible after total knee arthroplasty (TKA). The purpose of this study was to investigate the effects of TKA on motion patterns in patients with OA of the knee. METHOD: 50 patients with knee OA were investigated prior and at 33 +/- 8 months after unilateral TKA. The control group comprised 17 healthy volunteers matched to the study group with respect to age. The gait analysis was performed with an optoelectronic motion analysis system (Elite(R), Italian). RESULTS: Step length, step duration and velocity increased after surgery (p < 0.05), but remained lower than the values of the controls (p < 0.05). Extension angles in stand and swing phase remained unchanged and significantly lower when compared to control values (p = 0.01, p = 0.04). Flexion angles in swing (p = 0.02) and stand phase (p = 0.01) increased on the operated side and were significantly higher than the flexion angle in the control group (p = 0.02, p = 0.03). Reextension in stand phase, which was investigated for quantification of functional range of motion, increased bilaterally after surgery (p < 0.01), but remained lower than the reextension of the controls (p 相似文献   

Gait analysis outcomes of percutaneous medial hamstring tenotomies in children with cerebral palsy

BACKGROUND: Hamstring lengthening procedures are commonly performed on children with cerebral palsy (CP) to improve gait. The purpose of this study was to determine the efficacy of percutaneous hamstring tenotomy surgery for children with ambulatory CP. METHODS: In this retrospective study, subjects were included if they had a diagnosis of CP and had computerized gait analysis data collected before and after surgery. Subjects were not included in the study if they had any open hamstring lengthening on the same side. Other concomitant lower extremity surgeries were not exclusionary. Short- and long-term follow-up groups were established: if the time from their surgery to their gait laboratory was less than 18 months, they were placed in the short-term follow-up group, and if the time from their surgery to their gait laboratory was greater than 18 months, they were placed in the long-term follow-up group. RESULTS: The results demonstrated that for short- and long-term groups on preoperative to postoperative analysis, there was significantly improved knee extension at initial contact, increased velocity, increased stride length, improved overall gait as indicated by a decrease in a 16 variable multivariate index (Gillette Gait Index), and a decreased popliteal angle. For the short-term group only, additional significant findings included increased peak knee extension in stance and reduced plantar flexion at initial contact. The absolute values of peak knee extension in stance and plantar flexion at initial contact were equivalent at follow-up for the short- and long-term groups. Increased anterior pelvic tilt was also significant for the short-term follow-up group only. CONCLUSIONS: The findings of this study demonstrate that the minimally invasive technique of percutaneous hamstring tenotomy is effective in improving key dynamic gait parameters for individuals with CP for a short period, and these benefits are maintained in the long term. LEVEL OF EVIDENCE: Level IV.