Distal hamstring lengthening in cerebral palsy

Summary Distal elongation of the hamstrings was performed for contracture due to neurogenic disorders in 66 patients. A follow-up study on 34 of the patients with cerebral palsy is reported here. The success of the operation was judged by functional evaluation including joint measurement and gait analysis. The advantages of this operation and the need for prolonged aftercare are discussed.

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Résumé La contracture d'origine neurologique a été corrigée chez 66 malades par allongement des ischiojambiers au niveau de leurs tendons terminaux. L'article étudie les résultats à long terme obtenus chez 34 infirmes moteurs cérébraux. L'efficacité de l'intervention a été évaluée sur le plan fonctionnel d'après la mobilité articulaire et la qualité de la marche. La discussion porte sur les avantages de cette opération et la nécessité de soins post-opératoires prolongés.

     

Video-assisted gastrocnemius-soleus and hamstring lengthening in cerebral palsy patients

The aim of the study was to present the results of video-assisted fractional lengthening of the triceps surae muscle and the hamstrings in children with spastic cerebral palsy. In the period from September 2003 to December 2004, triceps surae muscle contractures were treated in 35 lower extremities (22 patients) and hamstring lengthening was performed in 12 knees (eight patients). The patients were between 4 and 10 years of age. Lengthening of the gastrocnemius-soleus was sufficient for achieving 10 degrees dorsiflexion of the foot in 31 of the 35 extremities. The short-term follow-up, at least 1 year after operation, did not reveal any complications. The hamstring lengthening resulted in full correction in nine knees; one endoscopic procedure required conversion to open surgery owing to bleeding. In one case, incomplete sciatic nerve palsy developed. Video-assisted gastrocnemius-soleus recession as well as video-assisted lengthening of the hamstrings proved to be fully efficient in the group reported here.     

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.     

Lateral hamstring transfer and gait improvement in the cerebral palsy patient.

A retrospective analysis of twenty-three spastic patients who underwent forty-three transfers of the semitendinosus muscle to the lateral intramuscular septum and of the semimembranosus muscle to the biceps is presented. Decreased knee-flexion deformity as well as improved walking function were achieved in 91 per cent. An unsatisfactory result was associated with complications of the procedure. Only one knee of the forty-three that were operated on showed late genu recurvatum. This procedure appears to be both effective and relatively free of late comlications.     

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.     

Functional changes in the antagonists after lengthening the agonists in cerebral palsy. II. Quadriceps strength before and after distal hamstring lengthening

In a recent study, 38 patients with spastic cerebral palsy (median age, 5.6 years) were examined before and at a median 13 months after distal lengthening of the hamstrings. Four weeks after operation, the strength of the quadriceps was reduced by a median value of 70%. Seven months after operation, the strength had been regained; by 13 months after operation, it had increased by a median value of 22%. In 20 cases, strength had increased by more than 50%. The present study confirms the theory that quadriceps function is strengthened when the antagonist function is weakened. The study also explains (1) why it often takes six months for gait to become better than before operation and (2) why spasticity of the rectus often increases after the hamstrings are lengthened.     

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.     

Distal hamstring lengthening in cerebral palsy: the influence of the proximal aponeurotic band of the semimembranosus

We undertook a prospective review of 24 children with spastic diplegia treated by distal hamstring fractional lengthening at the Sheffield Children's Hospital. In 14 children (24 limbs) the correction achieved (popliteal angle) was inadequate and in these patients in the operating room a further correction was attained by dividing a tight band palpated in the substance of the semimembranosus muscle. Under general anaesthetic (preoperatively) the popliteal angle (a degrees ) was measured using a goniometer, then again (b degrees ) following distal hamstring fractional lengthening and finally (c degrees ) after surgically dividing the tight band. The mean preoperative popliteal angle (a degrees ) in all 24 limbs was 65 degrees (52-90). Following the standard hamstring fractional lengthening it (b degrees ) measured 37 degrees (35-50) and after division of the tight band it (c degrees ) measured 15 degrees (10-20). The reduction in popliteal angle following release of the tight band (proximal aponeurosis) was statistically significant (P<0.05). We undertook a cadaveric examination of 22 lower limbs and confirmed in all the cases that this band was the proximal aponeurosis of the semimembranosus muscle. The proximal aponeurosis is a well defined band located at the anterior aspect of the semimembranosus muscle where it arises from the tendon of the proximal attachment. It is separate from the distal aponeurosis. Division of the proximal aponeurosis during fractional lengthening of the distal hamstring in patients with cerebral palsy results in a significant reduction in the flexion deformity.     

Proximal femoral diaphysectomy in cerebral palsy

A study was conducted to evaluate the outcome of massive proximal femoral shortening in the cerebral palsy patient with severe spastic quadriplegia and hip instability. A retrospective review of 13 children (age range: three to 19 years of age) representing 18 hips treated with massive shortening of the proximal femur was conducted. Bilateral procedures were performed in five patients. All procedures were performed between February 1986 and March 1990. Radiographs were evaluated for preoperative and postoperative migration percentage (MP) and femoral neck-shaft angle (NSA). Charts were reviewed for complications and clinical results. All femoral osteotomies healed without difficulty. Clinical follow-up averaged 27.6 months. Satisfactory results occurred in all but one hip. Radiographs taken an average of 19.5 months postoperatively showed improved MP in all but one hip. The average preoperative MP was 70% and postoperative MP was 18%. Femoral NSA also was improved. Heterotopic bone formed in 13 hips but caused no significant problems. Other complications included postoperative seizure, urinary tract infection, cast sores, transient arm weakness, weight loss, pin protrusion through skin, and femur fracture after cast removal. Based on the good results and minimal complications in this series, massive femoral shortening appears to be a superior alternative to proximal femoral resection in these difficult patients.     

Functional changes in the antagonists after lengthening the agonists in cerebral palsy. I. Triceps surae lengthening

In a recent study, children with spastic cerebral palsy (median age, five years) were examined before and up to a median of 14 months after 52 operations involving elongation of the tendo Achillis or aponeurotomy of the gastrocnemius. On removal of the cast four weeks postoperatively, strength in the dorsiflexors had increased by more than 50%, as evaluated by the ability to raise a weight from a scale. Postoperative function was correlated with preoperative function. Strength had increased more than 200% by 14 months postoperatively, with no instance of excessive lengthening of the triceps. In 13 cases, the dorsiflexors had been without function preoperatively. Two of those cases again lost the dorsiflexor function achieved postoperatively, when dynamic shortening recurred after one year. The study thus confirms the view that antagonist function improves when spasticity in the agonist is reduced by tendon lengthening.     

Proximal femoral resection-interposition arthroplasty in cerebral palsy

Hip dislocation is common in children with total body cerebral palsy. It is associated with pain, difficulty in seating and problems with perineal hygiene. We present a retrospective study of 15 patients who had undergone 21 proximal femoral resection-interposition arthroplasties between 1990 and 2005. The mean age at the time of surgery was 16.2 years (range 11-26 years). Mean follow-up was 3.4 years (range 1-7 years). Ninety percent of patients had pain relief. Perineal hygiene and sitting was improved in all cases. A lateral femoral head defect was noted in 90% of hips and was associated with pain, and significant degenerative changes. Twelve hips had heterotopic ossification (11 type-1, one type-2 and 0 type-3). No major complications were seen. We would submit that proximal femoral resection is a good salvage procedure for the painful, dislocated hip, with an excellent chance of resolving symptoms. The finding of a lateral femoral head defect on the radiograph is associated with significant degenerative changes.     

Distal hamstring elongation in the management of spastic cerebral palsy

Forty-nine children with spastic cerebral palsy treated by distal hamstring elongation and followed for an average of 4.4 years were reviewed. The aim of the operation was to release hamstring tightness to improve the patients' level of function and efficiency and the cosmetic appearance of their gait. Forty patients had significant improvement in gait pattern, and 18 had improved motor function. Complications included transient stiff-legged gait and exaggerated lumbar lordosis. One patient with spastic quadriceps had 15 degrees of persistent genu recurvatum.     

Effectiveness of serial stretch casting for resistant or recurrent knee flexion contractures following hamstring lengthening in children with cerebral palsy

A retrospective review of all cerebral palsy (CP) patients with resistant or recurrent knee flexion contractures treated with serial stretch casting was performed. The protocol consisted of sequential wedging (5 degrees per week) of fiberglass casts until maximum knee extension had been achieved. Measurements were made prior to the initiation of casting, at completion of the casting, and at 1 year after the casting. Forty-six subjects, with 75 involved extremities, met the study inclusion criteria. Mean age at the time of initiation of casting was 12.7 years. Using radiographic measurements, the mean initial degree of knee flexion contracture was -17.6 degrees. At the completion of casting, the mean knee flexion angle was -8.1 degrees. The mean duration of casting was 30 days. At 1 year after completion of the casting, the mean knee flexion angle was -12.2 degrees. Initial correction to within 10 degrees of full extension was achieved in 76% of extremities. Age less than 12 years and initial flexion contracture of less than -15 degrees were statistically significant factors related to maintenance of correction at 1 year. Complications included soft tissue compromise in 13 extremities (17%), transient neurapraxia in 9 extremities (12%), and tibial subluxation in 1 extremity (1%). Serial stretch casting was successful in correcting resistant knee flexion contractures in the majority of cases. Casting was less effective in teenagers and those with larger contractures. Complications were minimized by proper casting technique and controlled rate of correction.     

A long-term retrospective study of proximal hamstring release for hamstring contracture in cerebral palsy

Proximal hamstring release was used exclusively for hamstring contracture in patients with spastic cerebral palsy. Average follow-up was 9 years 5 months. Thirty-two of 78 patients were examined retrospectively. Straight leg raising increased from 30 to 68 degrees. Knee flexion contracture decreased from 16 to 9 degrees. Knee flexion contractures of greater than 10 degrees were not permanently corrected. Only four of 64 knees were in mild (5-10 degrees) recurvatum at follow-up. Lumbar lordosis averaged 53 degrees at follow-up, and hip flexion contracture release apparently had little effect on lumbar lordosis. Proximal hamstring release can be used by this described technique without severe lumbar lordosis or devastating genu recurvatum.     

Isolated calf lengthening in cerebral palsy. Outcome analysis of risk factors

We assessed the medium-term outcome of three methods of isolated calf lengthening in cerebral palsy by clinical examination, observational gait analysis and, where appropriate, instrumented gait analysis. The procedures used were percutaneous lengthening of tendo Achillis, open Z-lengthening of tendo Achillis and lengthening of the gastrosoleus aponeurosis (Baker's procedure). We reviewed 195 procedures in 134 children; 45 had hemiplegia, 65 diplegia and 24 quadriplegia. We established the incidence of calcaneus and recurrent equinus and identified 'at-risk' groups for each. At follow-up, 42% had satisfactory calf length, 22% had recurrent equinus and 36% calcaneus. The incidence of calcaneus in girls at follow-up was significantly higher (p = 0.002) while boys had an increased rate of recurrent equinus (p = 0.012). Children with diplegia who had surgery when aged eight years or younger had a 44% risk of calcaneus, while those over eight years had a 19% risk (p = 0.046). Percutaneous lengthening of tendo Achillis in diplegia was the least predictable, only 38% having a satisfactory outcome compared with 50% in the other procedures. The incidence of recurrent equinus in hemiplegic patients was 38%. Only 4% developed calcaneus. The type of surgery did not influence the outcome in patients with hemiplegia or quadriplegia. Severity of involvement, female gender, age at operation of less than eight years and percutaneous lengthening of tendo Achillis were 'risk factors' for calcaneus. Hemiplegia, male gender, and an aponeurosis muscle lengthening increased the risk of recurrent equinus.