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.     

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.     

Proximal rectus femoris release surgery is not effective in normalizing hip and pelvic variables during gait in children with cerebral palsy

The purpose of this study was to determine the efficacy of the proximal rectus femoris release to treat hip flexor contractures and hip and pelvic gait deviations in children with spastic cerebral palsy. This study was a retrospective repeated-measures analysis of data collected on two matched groups of patients, those with and without proximal rectus femoris release surgery, seen in our Motion Analysis Laboratory. Proximal rectus release surgery did not improve hip extension, did not decrease anterior pelvic tilt, and did not improve temporal-distance measures of gait in children with cerebral palsy. A multivariate measure, the Hip Flexor Index, was also unchanged. The group of patients without any hip flexor surgery was not different from the rectus femoris release group on hip or pelvic variables before or after surgery. The findings of this study offer no evidence that the proximal rectus femoris release is successful in achieving desired gait outcomes at the hip and pelvis in children with cerebral palsy.     

Surgical treatment of knee dysfunction in cerebral palsy

The prerequisites for normal gait are: (1) stability in the stance phase of gait, (2) clearance of the foot in the swing phase, (3) proper foot preposition in swing, and (4) an adequate step length. In the stance phase, the knee provides shock absorption and energy conservation; in the swing phase, it allows foot clearance. To accomplish these functions, the knee must extend fully in stance and flex approximately 60 degrees in swing. Consequently, balanced muscle action at the hip, knee, and ankle joints, combined with adequate acceleration from the hip flexor and triceps surae muscles, is essential. In the crouch gait of spastic cerebral palsy, hamstring lengthening alone often converts the flexed-knee gait to an extended-knee, stiff-legged gait with inadequate swing-phase knee flexion. This unwanted conversion is due to cospasticity of the quadriceps and hamstring muscles. Restoration of normal knee function in patients with spastic paralysis is more successful when fractional hamstring lengthening is combined with a transfer of the distal rectus femoris tendon to either the iliotibial band or the distal tendon of the semitendinosus.     

Predictive value of the Duncan-Ely test in distal rectus femoris transfer

Fifty-six patients who underwent 94 distal rectus femoris transfers and pre- and postoperative gait analyses were retrospectively reviewed. The patients were divided into three groups based on pre- and postoperative Duncan-Ely tests. Group A (34 limbs) had positive tests both before and after surgery. Group B (46 limbs) had positive tests before surgery and negative tests after surgery. Group C (13 limbs) had negative tests both before and after surgery. One limb had a negative test before surgery and a positive test after surgery and was not included in any group. Knee arc increased significantly in both groups with positive preoperative Duncan-Ely tests (groups A and B), but not in the group with negative preoperative tests (group C). The timing of peak knee flexion in swing improved in all groups, but the change was smaller and not statistically significant in the group with negative preoperative tests (group C). The findings of the current study indicate that the Duncan-Ely test may be a helpful predictor of outcome in children for whom distal rectus femoris transfer is being considered. Caution should be exercised when patients have weak quadriceps and a negative Duncan-Ely test before surgery, particularly when concurrent calf lengthening procedures are planned.     

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.     

Analysis of two different techniques in the treatment of knee stiffness in swing phase due to fibrous rectus femoris muscle in children

The objective of this study was to analyze two surgical techniques in the treatment of fibrous rectus femoris muscle in children. Data from 152 patients (161 knees) from July 1991 to December 2004 were analyzed. Clinical signs were knee stiffness in swing phase, positive Ely and Ober tests, and abnormal flexion angles of the knee and hip. Patients were operated according to one of two variants: variant A, to release the proximal tendon and variant B, to release the middle shaft of the rectus femoris muscle. There were 96 women (63.2%) and 56 men (36.8%) in this study. Bilateral involvement was found in nine patients; only the left knee was affected in 34 patients (22.4%) and only the right knee in 109 patients (71.7%). All 152 patients (161 knees) developed fibrous rectus femoris muscle (RFM) after repeated intramuscular injection of antibiotic(s) into the RFM. A total of 145 knees (136 patients) were classified as severe and 16 knees (16 patients) were classified as moderate. Overall, we attained excellent results in 109 (67.7%), good results in 26 (16.1%), fair results in 14 (8.7%), and poor results in 12 knees (7.5%). There have been no complications so far. Generally, surgical treatment of knee stiffness in swing phase due to fibrous RFM according to variant B led to postoperative poor results in only 1.2% of patients, whereas variant A gave postoperative poor results in 14.5% of patients. The surgical procedure is simple and safe, and knee and hip functions, tendency for crouch gait, and anterior pelvic tilt were remarkably improved.     

Distal rectus femoris surgery in children with cerebral palsy: results of a Delphi consensus project

PurposeThe purpose of this study was for an international panel of experts to establish consensus indications for distal rectus femoris surgery in children with cerebral palsy (CP) using a modified Delphi method.MethodsThe panel used a five-level Likert scale to record agreement or disagreement with 33 statements regarding distal rectus femoris surgery. The panel responded to statements regarding general characteristics, clinical indications, computerized gait data, intraoperative techniques and outcome measures. Consensus was defined as at least 80% of responses being in the highest or lowest two of the five Likert ratings, and general agreement as 60% to 79% falling into the highest or lowest two ratings. There was no agreement if neither threshold was reached.ResultsConsensus or general agreement was reached for 17 of 33 statements (52%). There was general consensus that distal rectus femoris surgery is better for stiff knee gait than is proximal rectus femoris release. There was no consensus about whether the results of distal rectus femoris release were comparable to those following distal rectus femoris transfer. Gross Motor Function Classification System (GMFCS) level was an important factor for the panel, with the best outcomes expected in children functioning at GMFCS levels I and II. The panel also reached consensus that they do distal rectus femoris surgery less frequently than earlier in their careers, in large part reflecting the narrowing of indications for this surgery over the last decade.ConclusionThis study can help paediatric orthopaedic surgeons optimize decision-making for, and outcomes of, distal rectus femoris surgery in children with CP.Level of evidenceV     

Sagittal knee kinematics after rectus femoris transfer without hamstring lengthening

The purpose of this study was to assess the sagittal knee kinematics of rectus femoris transfer without hamstring lengthening. A retrospective review of seventeen children (29 knees) was performed. Gait analysis was performed prior to surgery and repeated at a minimum of one year after surgery. Sagittal knee kinematics were analyzed. Stance minimum knee flexion increased 7 degrees; swing maximum knee flexion increased 5 degrees; and swing minimum knee flexion increased 5 degrees. The present study confirmed previously reported increases in swing maximum knee flexion. Increases in stance minimum knee flexion and swing minimum knee flexion were also found. These findings have not been previously reported.     

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.     

Three-dimensional muscle-tendon geometry after rectus femoris tendon transfer

BACKGROUND: Rectus femoris tendon transfer is performed in patients with cerebral palsy to improve knee flexion during walking. This procedure involves detachment of the muscle from its insertion into the quadriceps tendon and reattachment to one of the knee flexor muscles. The purpose of the present study was to evaluate the muscle-tendon geometry and to assess the formation of scar tissue between the rectus femoris and adjacent structures. METHODS: Magnetic resonance images of the lower extremities were acquired from five subjects after bilateral rectus femoris tendon transfer. A three-dimensional computer model of the musculoskeletal geometry of each of the ten limbs was created from these images. RESULTS: The three-dimensional paths of the rectus femoris muscles after transfer demonstrated that the muscle does not follow a straight course from its origin to its new insertion. The typical muscle-tendon path included an angular deviation; this deviation was sharp (>35 degrees ) in seven extremities. In addition, scar tissue between the transferred rectus femoris and the underlying muscles was visible on the magnetic resonance images. CONCLUSIONS: The angular deviations in the rectus femoris muscle-tendon path and the presence of scar tissue between the rectus femoris and the underlying muscles suggest that the beneficial effects of rectus femoris tendon transfer are derived from reducing the effects of the rectus femoris muscle as a knee extensor rather than from converting the muscle to a knee flexor. These findings clarify our understanding of the mechanism by which rectus femoris tendon transfer improves knee flexion.     

Effects of surgical lengthening of the hamstrings without a concomitant distal rectus femoris transfer in ambulant patients with cerebral palsy

Eighteen ambulant patients (32 legs) who had undergone fractional lengthening of the medial and lateral hamstrings without rectus femoris transfer underwent pre- and postoperative gait analysis. A significant increase in the amount of knee extension and a decrease in the amount of peak knee flexion in swing were observed. This decrease in knee flexion signified a change towards more normal speed-related values. Dorsiflexion at initial contact decreased significantly for patients who did not undergo a gastrocnemius lengthening (n = 24). Absolute cadence was significantly lower after surgery, but the change in dimensionless cadence was not significantly different. This difference in the outcome between dimensionless and absolute stride parameters can be attributed to the increase in body height after surgery. The clinical significance of these findings is that it is important to recognize that postoperative effects of surgery on gait in children may, in part, be explained by changes in height and not surgery alone.     

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.     

Sagittal knee kinematics following combined hamstring lengthening and rectus femoris transfer

The purpose of this study was to review knee kinematics following combined hamstring lengthening and rectus femoris transfer. Previous findings reported in the literature include kinematic changes in the magnitude of stance-phase maximum knee flexion, stance-phase minimum knee flexion (extension), and swing-phase maximum knee flexion; the timing of swing-phase maximum knee flexion and swing-phase minimum knee flexion (extension); and total knee excursion. Twenty-three children underwent bilateral (22) or unilateral (1) hamstring lengthening and rectus femoris transfer (45 knees) at the Shriners Hospitals for Children in Lexington, KY between January 1996 and December 2001. Sagittal knee kinematic data were obtained as part of a complete gait study accomplished before surgery and at 1 year after surgery. Values were compared using a paired t test method set at a p < .05 level to determine statistical significance. Changes were seen in the magnitude of stance-phase maximum knee flexion, stance-phase minimum knee flexion (extension), swing-phase maximum knee flexion, and swing-phase minimum knee flexion (extension); in the timing of swing-phase maximum knee flexion; and in total knee excursion.     

Free functional rectus femoris muscle transfer for restoration of knee extension and defect coverage after trauma.

In March of 2000 and May of 2002, two patients underwent restoration of knee extension with a free neurovascular rectus femoris flap. The female patient was 10 years and the male patient 19 years old. Both patients sustained a complex trauma of the thigh with fracture of the femur and posttraumatic loss of quadriceps femoris muscles. Follow up of the patients was 51 and 27 months. After 8 months reinnervation were detected by Electromyography (EMG) in both patients and contraction became visible 2 months later. The female patient obtained a good and the male patient a very good functional result. Both patients were able to walk unaided. The authors concluded that free functional rectus femoris transfer can obtain excellent results in treating knee extension and soft-tissue defect due to trauma and loss of the quadriceps femoris muscles.     

Conversion of biarticular to monoarticular muscles as a component of multilevel surgery in spastic diplegia

We treated 20 children (40 limbs) with diplegic cerebral palsy who could walk by multilevel soft tissue operative procedures including conversion of the biarticular semitendinosus and gastrocnemius to monoarticular muscles. The mean age at surgery was 11.5 years (5.6 to 17.0). All patients underwent clinical and radiological examination and three-dimensional instrumented gait analysis before and at a mean of 3.1 years (2.0 to 4.5) after surgery. The passive range of movement at the ankle, knee and hip showed improvement at follow-up. Kinematic parameters indicated a reduced pelvic range of movement and improvement of extension of the knee in single stance after operation (p < 0.0001). However, post-operative back-kneeing was detected in five of the 40 limbs. The kinetic studies showed that the power of the hamstrings and plantar flexors of the ankle was maintained while the maximum knee extensor moment during stance was reduced. The elimination of knee flexor activity of semitendinosus and gastrocnemius combined with transfer of distal rectus femoris led to an improvement in gait as confirmed by gait analysis.     

The effects of resection of the proximal part of the fibula on stability of the knee and on gait

We studied six patients to determine the effects of unilateral marginal resection of the proximal part of the fibula on stability of the knee and on gait. At the time of the operation, the fibular collateral ligament and the tendon of the biceps femoris were reattached, but no attempt was made to stabilize the fibula otherwise. The patients were tested an average of sixty-one months after operation. Stability of the knee was measured with an instrumented system. Gait was evaluated with an optical electronic three-dimensional digitizing system and a multicomponent force-platform. The gait of six healthy control subjects of similar age was also studied, and the reproducibility of measurements of stability of the knee was investigated in four healthy adults. There were significant differences between the side on which an operation had been done and the contralateral side with regard to the extent of anterior translation and of total anterior-posterior translation of the tibia at both 20 and 90 degrees of flexion of the knee, and in total varus and valgus rotation of the knee (the number of degrees from a position of maximum varus to one of maximum valgus angulation) at 20 degrees of flexion. The measurements of gait and of motion of the knee were found to be normal when compared with those in the control subjects. In the ground-reaction measurements, there were some significant differences from normal in the medial-lateral plane, but they were clinically unimportant. Resection of the proximal part of the fibula can lead to instability of the knee.     

Kinematic and kinetic outcomes after identical multilevel soft tissue surgery in children with cerebral palsy

This study evaluates the outcomes of multilevel soft tissue surgery in 31 ambulatory children (n = 39 sides) with cerebral palsy. All children had undergone rectus femoris transfer, hamstring lengthening, and gastrosoleus lengthening for the purpose of correcting sagittal plane abnormalities. There were no simultaneous bony surgeries. Preoperative and postoperative evaluation consisted of clinical assessment and gait analysis, including 3-dimensional kinematics and kinetics. Results demonstrated improvements in knee and ankle function. At the knee, there was a decrease in mean flexion at initial contact (from 31 degrees [SD, +/-8 degrees] to 21 degrees [SD, +/-10 degrees]) and in stance (mean stance, 22 degrees [SD, +/-12 degrees] to 16 degrees [SD, +/-11 degrees]) associated with a decreased mean internal extensor moment in stance (from 0.09 Nm/kg [SD, +/-0.24 Nm/kg] to -0.03 [SD, +/-0.22 Nm/kg]). At the same time, knee flexion was preserved in swing and occurred earlier. At the ankle, mean dorsiflexion improved at the time of examination (from 8 degrees [SD, +/-9 degrees] to 14 degrees [SD, +/-11 degrees] with the knee in extension), in terminal stance (peak from 7 degrees [SD, +/-9 degrees] to 12 degrees [SD, +/-8 degrees]), and in swing. Peak ankle power generation in stance was preserved and shifted later in stance toward push-off, with no functional weakening of the ankle plantar flexors. A longer-term assessment of a subset of patients with a second postoperative gait analysis at a mean of 4 years after surgery showed that gains measured at 1 year were maintained during the longer term. A subgroup demonstrating a jump knee gait pattern (as defined by excessive knee flexion at initial contact followed by rapid knee extension to full knee extension in midstance) had a tendency to go into knee hyperextension in stance with resultant net knee flexor moment after surgery. This raises concern about the indications for hamstring lengthening in this patient group.     

Rectus and hamstring surgery in cerebral palsy: a gait analysis study of results by functional ambulation level

The purpose of this study is to determine if children more severely involved with cerebral palsy respond as well to rectus transfer and hamstring surgery as those with less severe involvement. Ninety-nine children were classified as independent community ambulators, crutch/walker-dependent community ambulators, or household/exercise ambulators. Maximum knee extension in stance and total range of knee motion in gait increased following surgery in all groups. Peak knee flexion in swing was maintained in the independent group only, but timing of knee flexion in swing improved in all groups. All groups showed increases in stride length, and the household/exercise group also showed an increase in walking speed. Four of 39 crutch/walker-dependent community ambulators and 13 of 21 household/exercise ambulators progressed to the next higher functional ambulation group.