Rectus transfer in spastic diplegia

Objectives  

Change of function of the rectus femoris through medial transfer of its distal tendon. This procedure transforms a hip flexor and knee extensor into a hip and knee flexor. Thus the muscle acts as a hip flexor during the terminal stance phase and swing phase and as a knee flexor during the swing phase. This permits the foot to clear the ground and to improve the spastic gait.     

Rectus Femoris Distal Tendon Resection Improves Knee Motion in Patients With Spastic Diplegia

Background  

Children with spastic diplegia frequently show excessive knee extension (stiff-knee gait) throughout swing phase, which may interfere with foot clearance. Abnormal rectus femoris activity is commonly associated with a stiff-knee gait. Rectus femoris transfer has been recommended to enhance knee flexion during swing. However, recent studies suggest the transfer does not generate a knee flexor moment but diminishes knee extension moment in swing and MRI studies show the transferred tendons can be constrained by scarring to underlying muscles. Thus, it is possible knee flexion would be improved by distal rectus release rather than transfer since it would not be adherent to the underlying muscles.     

Comparison of hamstring lengthening with hamstring lengthening plus transfer for the treatment of flexed knee gait in ambulatory patients with cerebral palsy

Purpose

Children with spastic diplegic and hemiplegic cerebral palsy frequently ambulate with flexed knee gait. There has been concern that hamstring lengthening used to treat this problem may weaken hip extension. This study evaluates the primary outcome of hamstring transfer plus lengthening in comparison with traditional hamstring lengthening in treating flexed knee gait in ambulatory patients with cerebral palsy.

Methods

A total of 47 children (67 lower limbs) ranging in age from 5 to 17 years old were included in this study. All subjects underwent a variety of additional surgeries at the time of the hamstring surgery as part of a multilevel treatment plan. All patients who met the inclusion criteria were divided into two groups, the hamstring lengthening alone group (HSL) and the hamstring transfer plus lengthening group (HST). Full gait analysis studies were done for all subjects pre-operatively and 1 year post-operatively.

Results

There were 25 patients (35 limbs) in the HSL group and 22 patients (32 limbs) in the HST group. There was no significant difference in age, gender, or the time from surgery to post-operative gait analysis between groups. On physical examination, both HSL and HST groups showed improvement in passive knee extension, popliteal angle, and straight leg raise. Maximum knee extension in stance phase was improved in both groups. The maximum hip extension in late stance phase was significantly improved only in the HST group. The peak hip extension power in stance phase showed significant improvement only in the HST group and a significant decrease for the HSL group.

Conclusions

The findings of this study demonstrated that both the HSL and HST procedures resulted in similar amounts of improvement in passive range of motion of the knee, as well in knee extension in stance during gait at 1 year post-operatively. However, with the HST procedure, there was better preservation of hip extension power and improved hip extension in stance. The HST procedure should be considered when hamstring surgery is performed.     

Combined split anterior tibial-tendon transfer and intramuscular lengthening of the posterior tibial tendon. Results in patients who have a varus deformity of the foot due to spastic cerebral palsy

Twenty patients who had a varus deformity of the foot secondary to spastic cerebral palsy had twenty-two operations involving combined split anterior tibial-tendon transfer and intramuscular lengthening of the posterior tibial tendon, with and without concomitant lengthening of the Achilles tendon. Preoperatively, all patients had had a dynamic varus deformity of the hindfoot and adduction of the forefoot in both the stance phase and the swing phase of gait. At an average follow-up of 6.2 years (range, 2.3 to 8.8 years), there were fourteen excellent, four good, and four poor clinical results. Two patients who had a fixed varus deformity of the hindfoot and one patient who had a very weak anterior tibial muscle had a poor result. We concluded that the combined procedure is effective for correction of a flexible varus deformity of the foot in patients who have spastic cerebral palsy.     

Joint angular velocity in spastic gait and the influence of muscle-tendon lengthening

BACKGROUND: Joint angular velocity (the rate of flexion and extension of a joint) is related to the dynamics of muscle activation and force generation during walking. Therefore, the goal of this research was to examine the joint angular velocity in normal and spastic gait and changes resulting from muscle-tendon lengthening (recession and tenotomy) in patients who have spastic cerebral palsy. METHODS: The gait patterns of forty patients who had been diagnosed with spastic cerebral palsy (mean age, 8.3 years; range, 3.7 to 14.8 years) and of seventy-three age-matched, normally developing subjects were evaluated with three-dimensional motion analysis and electromyography. The patients who had cerebral palsy were evaluated before muscle-tendon lengthening and nine months after treatment. RESULTS: The gait patterns of the patients who had cerebral palsy were characterized by increased flexion of the knee in the stance phase, premature plantar flexion of the ankle, and reduced joint angular velocities compared with the patterns of the normally developing subjects. Even though muscle-tendon lengthening altered sagittal joint angles in gait, the joint angular velocities were generally unchanged at the hip and knee. Only the ankle demonstrated modified angular velocities, including reduced dorsiflexion velocity at foot-strike and improved dorsiflexion velocity through mid-stance, after treatment. Electromyographic changes included reduced amplitude of the gastrocnemius-soleus during the loading phase and decreased knee coactivity (the ratio of quadriceps and hamstring activation) at toe-off. Principal component analyses showed that, compared with joint-angle data, joint angular velocity was better able to discriminate between the gait patterns of the normal and cerebral palsy groups. CONCLUSIONS: This study showed that muscle-tendon lengthening corrects biomechanical alignment as reflected by changes in sagittal joint angles. However, joint angular velocity and electromyographic data suggest that the underlying neural input remains largely unchanged at the hip and knee. Conversely, electromyographic changes and changes in velocity in the ankle indicate that the activation pattern of the gastrocnemius-soleus complex in response to stretch was altered by recession of the complex.     

Transfer of tibialis posterior tendon in cerebral palsy.

Posterior tendon transfer to the dorsum of the foot through the interosseous membrans is an effective procedure for spastic equinovarus deformity. The complications of excessive calcaneal or excessive valgus deformity can be avoided if the transfer is not inserted too tightly with the foot in dorsiflexion and if it is not transferred to a cuboid insertion. Electromyographic activity was demonstrated in some of the transferred muscles during the swing phase of gait. Tendo achillis lengthening in association with posterior tibial transfer must be done judiciously to avoid deformity of the calcaneus.     

The effects of hamstring lengthening on hip rotation

The purpose of this study is to determine the effect on hip rotation of hamstring lengthening as measured by preoperative and postoperative motion analysis. Thirty-eight patients/76 hips in children with cerebral palsy spastic diplegia were retrospectively reviewed using presurgical and postsurgical gait analysis. Physical examination and gait analysis showed an increase in knee extension and decreased popliteal angles postoperatively. Kinematic analysis showed an increase in knee extension and decreased hip internal rotation throughout the gait cycle postoperatively as well. No difference was seen between those with internal and external rotation pattern at the hip preoperatively. As a group, the patients did not improve enough to change from internal to external rotation at the hip, suggesting that children with cerebral palsy spastic diplegia with significant internal rotation gait should have other surgical options besides hamstring lengthening when internal rotation gait of the hip is to be treated.     

Gait patterns in spastic hemiplegia in children and young adults

Four homogeneous patterns of gait were defined in forty-six patients who had spastic hemiplegia secondary to cerebral palsy or other neurological disorders by analyzing kinematic data in the sagittal plane and electromyographic data. In Group I (twenty patients) the primary abnormality was a drop foot in the swing phase. The thirteen patients in Group II had a tight heel cord in the stance phase as well as a drop foot in the swing phase. The five patients in Group III also had more proximal involvement (that is, restricted motion of the knee) as well as an equinus deformity of the ankle. In Group IV, the eight patients had, in addition, restricted motion of the hip.     

Sagittal knee kinematics after hamstring lengthening

The purpose of this study was to analyze sagittal knee kinematics after hamstring lengthening. A retrospective analysis was performed of 16 children (32 knees) with cerebral palsy who underwent hamstring lengthening as an isolated surgical procedure. Gait analysis was performed before surgery and at a minimum of 1 year after surgery. Decreased stance maximum knee flexion, stance minimum knee flexion, swing maximum knee flexion, and swing minimum knee flexion were noted. Total knee excursion increased. The present study confirmed the previously reported increased total knee excursion with decreased stance minimum and swing maximum knee flexion.     

Comparison of hamstring transfer with hamstring lengthening in ambulatory children with cerebral palsy: further follow-up

Background

Overactivity or contractures of the hamstring muscles in ambulatory children with cerebral palsy (CP) can lead to either a jump gait (knee flexion associated with ankle plantar flexion) or a crouch gait (knee flexion associated with ankle dorsiflexion). Hamstring lengthening is performed to decrease stance knee flexion. However, this procedure carries the potential risk of weakening hip extension power as well as recurrence over time; therefore, surgeons have adopted a modified procedure wherein the semitendinosus and gracilis are transferred above the knee joint, along with lengthening of the semimembranosus and biceps femoris.

Purpose

The purpose of our study is to evaluate the differences between hamstring lengthening alone (HSL group) and hamstring lengthening plus transfer (HST group) in the treatment of flexed knee gait in ambulatory children with CP. We hypothesized that recurrence of increased knee flexion in the stance phase will be less in the HST group at long-term follow-up, and hip extensor power will be better preserved.

Methods

Fifty children with CP who underwent hamstring surgery for flexed knee gait were retrospectively reviewed. All subjects underwent a pre-operative gait study, a follow-up post-operative gait study, and a long-term gait study. The subjects were divided into two groups; HSL group (18 subjects) or HST group (32 subjects). The mean age at surgery was 9.9 ± 3.3 years. The mean follow-up time was 4.4 ± 0.9 (2.7–6.3) years.

Results

On physical examination, both groups showed improvement in straight leg raise, knee extension, popliteal angle, and maximum knee extension in stance at the first post-op study, and maintained this improvement at the long-term follow-up, with the exception of straight leg raise, which slightly worsened in both groups at the final follow-up. Both groups improved maximum knee extension in stance at the initial follow-up, and maintained this at the long-term follow-up. Only the HST group showed significant (p < 0.05) improvement in the peak hip extension power in stance at the first post-op study, and this increased further at the final follow-up. In the HSL group, there was an initial slight decrease in the hip extension power, which subsequently increased to pre-operative values at the long-term study. Only the HST group showed increase of the average anterior pelvic tilt at the long-term follow-up study, although this was small in magnitude. There were two subjects who developed knee recurvatum at the post-op study, and both were in the HST group.

Conclusions

There is no clear benefit in regards to recurrence when comparing HST to HSL in the long term. In both HSL and HST, there was reduction of stance phase knee flexion in the long term, with no clear advantage in either group. Longer follow-up is needed for additional recurrence information. There was greater improvement of hip extension power in the HST group, which may justify the additional operative time of the transfer.

Significance

This study helps pediatric orthopedic surgeons choose between two different techniques to treat flexed knee gait in patients with CP by showing the long-term outcome of both procedures.     

Outcome of patients after Achilles tendon lengthening for treatment of idiopathic toe walking

Fifteen children who were diagnosed with idiopathic toe walking that cannot be corrected by nonoperative treatment were assessed by clinical examination and computer-based gait analysis preoperatively and approximately 1 year after Achilles tendon lengthening. Passive dorsiflexion improved from a mean plantarflexion contracture of 8 degrees to dorsiflexion of 12 degrees after surgery. Ankle kinematics normalized, with mean ankle dorsiflexion in stance improving from -8 to 12 degrees and maximum swing phase dorsiflexion improving from -20 to 2 degrees. Peak ankle power generation increased from 2.05 to 2.37 W/kg but did not reach values of population norms. No patient demonstrated clinically relevant triceps surae weakness or a calcaneal gait pattern. Seven patients had a stance phase knee hyperextension preoperatively, and 6 of these corrected after surgery. Achilles tendon lengthening improves ankle kinematics without compromising triceps surae strength; however, plantarflexion power does not reach normal levels at 1 year after surgery.     

The effect on gait of lengthening of the medial hamstrings in cerebral palsy

The purpose of this study was to analyze the effect of lengthening of the medial hamstrings on the gait of patients who had spastic cerebral palsy. Thirty-one patients had preoperative and postoperative gait analyses. Standard parameters, such as velocity, cadence, and stride length, were evaluated, as were motion graphs of the hip, knee, and ankle. There was little difference between the preoperative and postoperative mean values for velocity, cadence, and stride length, which were expressed as percentages of normal for the patient's age. The contours of the postoperative motion graphs of the knees changed very little compared with those of the preoperative graphs; when a graph showed restricted motion preoperatively, it did so postoperatively. Although extension of the knee in stance phase improved postoperatively, the improvement was accompanied by decreased flexion of the knee during swing phase. When spasticity of both the hamstrings and the quadriceps was noted on the preoperative electromyogram, motion of the knee in the sagittal plane was markedly restricted.     

Adult-onset hemiplegia: changes in gait after muscle-balancing procedures to correct the equinus deformity

Fifty-four adult patients with acquired spastic equinus and equinovarus deformity were treated with lengthening of the Achilles tendon, lateral transfer of the anterior tibial tendon, and appropriate muscle releases. All patients had preoperative dynamic electromyography and electrogoniometry performed in order to assist in planning the surgical procedures and to provide a baseline assessment of the dynamic deformities. Preoperatively, the stance and double-support phases of gait were prolonged. Throughout the stance phase, the gait of these patients was characterized by equinus deformity of the ankle, decreased flexion of the knee (hyperextension in the most severely involved patients), and increased flexion of the hip (which also varied with the severity of the equinus deformity of the ankle and hyperextension of the knee). In all patients, the operation was performed at least one year after onset of the hemiplegia. Clinical follow-up at an average of thirty months (range, twenty-four to sixty-two months) showed that the equinus deformity was corrected in all patients and that 59 per cent of them were brace-free. Two patients had a superficial infection that healed uneventfully, and two had pull-out of the tendon that required reoperation. Postoperative analyses of gait, performed at least one year after surgery for twenty-seven of the patients, showed that the stance and double-support phases of gait (which had been prolonged before surgery) approached the findings in normal control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of pediatric spastic foot deformities

The pathophysiology of gait under the influence of cerebral-spastic leg musculature and the resulting biomechanical effects are demonstrated. The latter must be taken into account for successful treatment of functional disturbances and in the shape of the feet in children with cerebral-spastic disturbances in movement. Co-contractions in antagonistic muscle groups of the lower extremities during the second half of the stance phase, the propulsion period of the step, are the main obstacles to achieving efficient gait. The causes lie in the spastic increase of the muscle stretch reflex as well as in a defect in the reciprocal inhibition of antagonistic muscle groups. Moderate equinus gait and an increase in the normal differences in the development of force by the dorsal and plantar flexing muscles represent effective physiological compensation for these disturbances. The common secondary changes in the shape of the foot resulting from spasticity and contractures of the muscles require long-term planning of treatment, including physiotherapy, plaster casts, plastic orthoses, orthopedic shoes and, in some cases, operations, which should be delayed as long as possible during the growth phase. Premature lengthening of the Achilles tendon regularly results in iatrogenic foot deformities.     

Outcome of medial versus combined medial and lateral hamstring lengthening surgery in cerebral palsy

Pre- and postoperative gait analysis and static measurements from 37 children with cerebral palsy who underwent hamstring lengthening were evaluated. Significant improvements in static and kinematic measures were noted after surgery in both groups. Although the differences were not statistically significant, there was a suggestion that combined medial/lateral hamstring lengthening may provide greater improvement in popliteal angle and maximum knee extension in stance. However, there also appears to be a greater risk of knee hyperextension during gait after combined medial and lateral hamstring lengthening than after medial hamstring lengthening alone. Postoperative calf spasticity also appears to be a risk factor for postoperative knee hyperextension. Assessment of calf spasticity may be important in patients undergoing medial and lateral hamstring lengthening. Additional treatments such as bracing and/or botulinum toxin injections to the calf to control equinus and knee hyperextension may be beneficial.     

Calcaneal lengthening osteotomy in spastic planovalgus feet

Purpose of StudyPlanovalgus deformity in cerebral palsy is disabling for the child in terms of increased energy expenditure during the gait cycle. The lever arm function of the foot is lost due to midfoot break and the achilles tendon is at a disadvantage being unable to lift the body weight during push-off. We evaluated the results of calcaneal lengthening osteotomy in such patients with clinical, radiological and gait parameters.Methods17 spastic feet in a sample of 10 children were included in our study. The children were classified according to the GMFCS classification system and clinical parameters such as heel valgus and heel rise tests, radiological angles such as Talo-calcaneal angle and Talo-navicular coverage angle on AP view and Calcaneal pitch angle, calcaneus-5th metatarsal angle and talus-1st metatarsal angle on lateral view were measured. Video gait analysis was performed to observe knee progression angle in mid stance and peak knee flexion angle in mid and terminal stance.ResultsImprovement was noted clinically in the heel valgus angle (preop-12.06°, postop-5.12°) and radiological parameters showed an improved coverage of the talus by navicular with simultaneous lifting of the medial longitudinal arch. Gait analysis showed decreased knee flexion trend in mid and terminal stance phase with better restoration of the knee axis.ConclusionCalcaneal lengthening osteotomy with peroneus brevis lengthening corrects almost all aspects of planovalgus deformity with an improved gait pattern without disturbing joint range of motion. It is a safe procedure for GMFCS grade 1 and 2 patients without much complications.     

Comparison of rectus femoris transposition with traditional transfer for treatment of stiff knee gait in patients with cerebral palsy

Purpose To assess the outcome of children with cerebral palsy following reposition of the distal rectus femoris tendon for treatment of stiff knee gait. Methods Children with cerebral palsy with stiff knee gait who underwent rectus femoris transfer were studied retrospectively. Inclusion criteria were cerebral palsy of diplegic or quadriplegic type, preoperative and 1 year postoperative three-dimensional motion analysis, and no other surgery except rectus femoris transfer at the time of study. The patients were separated into two groups: in group I, the rectus femoris was transferred to the distal medial hamstring tendons, either the gracilis or the semitendinosus; in group II, the distal tendon of the rectus femoris was transposed laterally and attached to the iliotibial band/intermuscular septum. Results Peak knee flexion during swing phase, total dynamic knee range of motion, knee range of motion during swing phase, and time to peak knee flexion during swing phase were all improved in both groups. Hip and pelvic kinematics were not influenced by the surgery. Velocity, stride length, and cadence were all improved following the surgery. There was no difference between the transfer group and the transposition group. Conclusion These findings suggest that distal transfer of the rectus femoris is effective in improving swing phase knee function by diminishing the mechanical effect of the dysphasic swing phase activity of the rectus femoris, not by converting the rectus femoris to an active knee flexor. No financial support was received for this study.     

Gait pattern in patients with spastic diplegic cerebral palsy who underwent staged operations

Fifteen patients with spastic diplegic cerebral palsy (CP) were monitored for a mean length of 9.5 years after they underwent staged operations and were evaluated by gait analysis, including joint motion in the sagittal plane and the ground reaction force (GRF) in three dimensions. Results showed an increased hip flexion (132%) at midstance, a reduction of peak knee flexion (PKF) during swing (45%) accompanied by an augmented time of PKF during swing (50%), and an increased dorsiflexion of the ankle during swing (293%) as well as its time during the gait cycle, in comparison with normal values. Moreover, significant decreases of the vertical GRF at the terminal stance and the forward and backward GRF were present. Additionally, it was found that a bilateral popliteal angle < 20 degrees is acceptable in spastic CP. Staged operations gave unpredictable results in the correction of contracture of the hamstrings, the Achilles tendon, and the iliopsoas. The authors are convinced that gait analysis is useful in evaluating these patients and enhances the results of operative treatment, and they have since changed their approach toward multilevel simultaneous corrections.     

Monitoring of the sciatic nerve during hamstring lengthening by evoked EMG

Traction injury to the sciatic nerve can occur during hamstring lengthening. The aim of this study was to monitor the influence of hamstring lengthening on conduction in the sciatic nerve using evoked electromyography (EMG). Ten children with spastic cerebral palsy underwent bilateral distal hamstring lengthening. Before lengthening, the evoked potential was recorded with the patient prone. During lengthening, it was recorded with the knee flexed to 90 degrees, 60 degrees and 30 degrees, and at the end of lengthening with the hip and knee extended. In all patients, the amplitude of the evoked EMG gradually decreased with increasing lengthening. The mean decrease with the knee flexed to 60 degrees was 34% (10 to 77), and to 30 degrees, 86% (52 to 98) compared with the pre-lengthening amplitude. On hip extension at the end of the lengthening procedure, the EMG returned to the pre-lengthening level. Monitoring of the evoked EMG potential of the sciatic nerve during and after hamstring lengthening, may be helpful in preventing traction injury.