Lengthening and transfer of hamstrings for a flexion deformity of the knee in children with bilateral cerebral palsy

Distal femoral osteotomy and patellar tendon advancement for the treatment of crouch gait in patients with bilateral spastic cerebral palsy

BACKGROUND

Crouch gait, or flexed knee gait, represents a common gait pattern in patients with spastic bilateral cerebral palsy (CP). Distal femoral extension and/or shortening osteotomy (DFEO/DFSO) and patellar tendon advancement (PTA) can be considered as viable options when knee flexion contractures are involved. Better outcomes have been reported after a combination of both, independently of the presence of knee extensor lag. In this study, we evaluated the clinical and kinematic outcomes of these procedures.

PATIENTS AND METHODS

We reviewed a cohort of 52 limbs (28 patients) who were treated for crouch gait by DFEO/DFSO alone (group 1, n = 15) or DFEO/DFSO + PTA (group 2, n = 37) as a part of single event multilevel surgery (SEMLS). The mean age at surgery was 14 years, and the mean follow-up time was 18 months. The physical examination data and three-dimensional standardized gait analysis were collected and analyzed before the surgery and postoperatively.

RESULTS

Overall knee range of motion improved in all limbs. The knee flexion decreased significantly in both groups at initial, mid, and terminal stance. Hip flexion significantly decreased in mid-stance for limbs in group 2. Both clinical and gait parameters were most improved in limbs who underwent DFEO/DFSO + PTA. Increased pelvic tilt was observed in both groups after surgery.

CONCLUSION

Although DFEO/DFSO alone was successful in correcting knee flexion contractures, PTA has helped to improve knee extensor lag and knee extension during gait.

LEVEL OF EVIDENCE

Therapeutic level IV.

Persistent increase in anterior pelvic tilt after hamstring lengthening in children with cerebral palsy

BACKGROUND

Hamstring lengthening has traditionally been the surgical treatment of choice to correct flexed knee gait in children with cerebral palsy (CP). Improved passive knee extension and knee extension during gait are reported post hamstring lengthening, but concurrent increased anterior pelvic tilt also occurs.

RESEARCH QUESTION

Does anterior pelvic tilt increase after hamstring lengthening in children with CP both in the short-term and mid-term, and what predicts increased post-operative anterior pelvic tilt?

METHODS

44 participants were included (age 7.2, SD 2.0 years; 5 GMFCS I, 17 GMFCS II, 21 GMFCS III, 1 GMFCS IV). Mean pelvic tilt was compared between visits, and the effect of potential predictors of change in pelvic tilt was examined using linear mixed models. The relationship of change in pelvic tilt to change in other variables was examined using Pearson correlation.

RESULTS

Anterior pelvic tilt increased significantly post-operatively by 4.8° (p < 0.001). It remained significantly higher by 3.8° at 2-15 years follow-up (p < 0.001). Change in pelvic tilt was not affected by sex, age at surgery, GMFCS level, assistance during walking, time since surgery, or baseline values of hip extensor strength, knee extensor strength, knee flexor strength, popliteal angle, hip flexion contracture, step length, walking speed, maximum hip power in stance, or minimum knee flexion in stance. Pre-operative dynamic hamstring length was associated with greater anterior pelvic tilt at all visits but did not affect amount of change in pelvic tilt. Patients in GMFCS I-II showed a similar pattern of change in pelvic tilt to GMFCS III-IV.

SIGNFICANCE

When considering hamstring lengthening for ambulatory children with CP, surgeons should weigh increased mid-term anterior pelvic tilt post-operatively with the desired outcome of improved knee extension in stance. Patients with neutral or posterior pelvic tilt and short dynamic hamstring lengths pre-operatively have lowest risk of excessive post-operative anterior pelvic tilt.

Long-term outcome of hamstring lengthening versus transfer and the role of biceps femoris lengthening in patients with spastic diplegia and dynamic knee flexion in gait

BACKGROUND

Orthopedic treatment of flexed-knee gait consists of hamstring lengthening along with surgery at other levels. Transfer of the semitendinosus (hamstring transfer) was introduced to avoid increase of anterior pelvic tilt as well as reduce risk of recurrence.

METHODS

We retrospectively assessed children with spastic cerebral palsy and flexed-knee gait pre-operatively, 1 year post-operatively, and at a minimum of 7 years post-operatively.

RESULTS

The 39 patients were a mean 9.4 ± 3.4 years at the time of surgery, 20 subjects underwent hamstring transfer, and 19 subjects had hamstring lengthening with mean follow-up 9.1 years. Passive range of motion improved initially, but regressed at long term. Dynamic minimum knee flexion in stance decreased in both groups at the first post-operative study, and was maintained at final follow-up in 64-67% of patients. There was a small increase in anterior pelvic tilt at the 1-year follow-up which subsequently decreased to less than pre-operative in the hamstring lengthening group but remained mildly increased (5°) in the hamstring transfer group at final follow-up. Success in correcting stance knee flexion of the entire group was 69% of the Gross Motor Function Classification System grades I and II and 60% of the Gross Motor Function Classification System grade III subjects. Gait profile Score and sagittal knee Gait Variable Score both showed clinically important improvement after surgery and was mostly maintained long term for both groups. Lateral hamstring lengthening was beneficial in more severe patients, with minimal risk of adverse effects.

CONCLUSION

Hamstring surgery as part of single event multi-level surgery (SEMLS) is effective in correcting flexed-knee gait in 60%-70% of patients with minimal effect on anterior pelvic tilt. There was no added advantage to hamstring transfer. Biceps Femoris lengthening may be beneficial and without significant additional risk.

LEVEL OF EVIDENCE

level III.

Mechanics of guided growth of the distal femur for correction of fixed knee flexion deformities: an extra-articular technique

INTRODUCTION

Anterior distal femoral hemiepiphysiodesis using intra-articular plates for correction of pediatric fixed knee flexion deformities (FKFD) has two documented complications: postoperative knee pain and implant loosening. The aim of this study is to investigate the mechanical properties of a novel extra-articular technique for anterior distal femoral hemiepiphysiodesis in patients with FKFD and to compare them to the conventional technique.

MATERIALS AND METHODS

Sixteen femoral sawbones were osteotomized at the level of the distal femoral physis and fixed by rail frames to allow linear distraction simulating longitudinal growth. Each sawbone was tested twice: first using the conventional technique with eight plates placed anteriorly just medial and lateral to the femoral sulcus (group A) and then with plates inserted in the proposed novel location at the most anterior part of the medial and lateral surfaces of the femoral condyles with screws in the coronal plane (group B). Gradual linear distraction was performed, and the resulting angular correction was measured. Strain gauges were attached to the plates, and the amount of strain (and equivalent stress) over the plates in response to linear distraction was recorded. The two groups were compared using the Wilcoxon signed-rank test.

RESULTS

The amount of angular correction was statistically higher in group B (extra-articular plates) at 5, 10-, and 15-mm of distraction (p < 0.001). As regards stress over the plates, the maximum stress and the area under the curve (sum of all stresses measured throughout the distraction process) were significantly higher when the plates were inserted at the conventional position (group A) (p < 0.001).

CONCLUSIONS

During anterior distal femoral hemiepiphysiodesis, the fixation of the eight plates in the coronal plane at the anterior part of the femoral condyles may produce a greater amount of correction and a lower degree of stress over the implants as compared to the conventional technique.

Finding consensus for hamstring surgery in ambulatory children with cerebral palsy using the Delphi method

PURPOSE

There is marked variation in indications and techniques for hamstring surgery in children with cerebral palsy. There is particular uncertainty regarding the indications for hamstring transfer compared to traditional hamstring lengthening. The purpose of this study was for an international panel of experts to use the Delphi method to establish consensus indications for hamstring surgery in ambulatory children with cerebral palsy.

METHODS

The panel used a five-level Likert-type scale to record agreement or disagreement with statements regarding hamstring surgery, including surgical indications and techniques, post-operative care, and outcome measures. Consensus was defined as at least 80% of responses being in the highest or lowest two of the five Likert-type ratings. General agreement was defined as 60%-79% falling into the highest or lowest two ratings. There was no agreement if neither of these thresholds was reached.

RESULTS

The panel reached consensus or general agreement for 38 (84%) of 45 statements regarding hamstring surgery. The panel noted the importance of assessing pelvic tilt during gait when considering hamstring surgery, and also that lateral hamstring lengthening is rarely needed, particularly at the index surgery. They noted that repeat hamstring lengthening often has poor outcomes. The panel was divided regarding hamstring transfer surgery, with only half performing such surgery.

CONCLUSION

The results of this study can help pediatric orthopedic surgeons optimize decision-making in their choice and practice of hamstring surgery for ambulatory children with cerebral palsy. This has the potential to reduce practice variation and significantly improve outcomes for ambulatory children with cerebral palsy.

LEVEL OF EVIDENCE

level V.

Knee flexion contracture impacts functional mobility in children with cerebral palsy with various degree of involvement: a cross-sectional register study of 2,838 individuals

Background and purpose - The impact of knee flexion contracture (KFC) on function in cerebral palsy (CP) is not clear. We studied KFC, functional mobility, and their association in children with CP.Subjects and methods - From the Swedish national CP register, 2,838 children were defined into 3 groups: no (≤ 4°), mild (5-14°), and severe (≥ 15°) KFC on physical examination. The Functional Mobility Scale (FMS) levels were categorized: using wheelchair (level 1), using assistive devices (level 2-4), walking independently (level 5-6). Standing and transfer ability and Gross Motor Function Classification (GMFCS) were assessed.Results - Of the 2,838 children, 73% had no, 14% mild, and 13% severe KFC. KFC increased from 7% at GMFCS level I to 71% at level V. FMS assessment (n = 2,838) revealed around 2/3 were walking independently and 1/3 used a wheelchair. With mild KFC (no KFC as reference), the odds ratio for FMS level 1 versus FMS level 5-6 at distances of 5, 50, and 500 meters, was 9, 9, and 8 respectively. Correspondingly, with severe KFC, the odds ratio was 170, 260, and 217. In no, mild, and severe KFC 14%, 47%, and 77% could stand with support and 11%, 25%, and 33% could transfer with support.Interpretation - Knee flexion contracture is common in children with CP and the severity of KFC impacts function. The proportion of children with KFC rose with increased GMFCS level, reduced functional mobility, and decreased standing and transfer ability. Therefore, early identification and adequate treatment of progressive KFC is important.

The influence of preoperative knee flexion contracture severity on short-term outcome of orthopedic surgery in ambulatory children with bilateral cerebral palsy

BACKGROUND

Indications and cutoff value of deformities to determine surgical procedures for flexed knee gait are not clear. The aim was to determine the influence of none or mild, and moderate preoperative knee flexion contracture on the improvement of gait after orthopedic surgery in children with bilateral cerebral palsy (CP).

METHODS

Inclusion criteria; bilateral CP, Gross Motor Function Classification System level I-III, and pre- and post operative-gait analysis. The 132 individuals identified were categorized into 2 groups based on the severity of knee flexion contracture (group 1: none or less than 11°; group 2: greater than or equal to 11°), and then matched according to the exact same soft tissue and/or bony orthopedic surgical procedures performed. The indication for surgery was to prevent progressive development of knee flexion contracture and stance phase flexed knee gait. Pre- and postoperative physical examination and gait analysis data were analyzed retrospectively.

RESULTS

Sixty (30 + 30) children, with mean age 10.6 years in each group, were included. The average follow-up time was 17 months. Gait Deviation Index (GDI) improved in group 1 from mean 66 (SD 19) to 74 (15), p = 0.004, and in group 2 from 60 (13) to 69 (15), p = 0.001. Knee flexion in stance improved in group 1 from 21.4 (16.1) to 12.1 (16.0) degrees, p = 0.002, and in group 2 from 32.2 (14.2) to 17.0 (15.9), p = 0.001. Step length improved in both groups, p = 0.017 and p = 0.008, respectively. Only in group 2 significant improvement was noted in walking speed, p = 0.018 and standing function, Gross Motor Function Measure (GMFM-D), p = 0.001. Knee flexion contracture decreased in group 1 from mean 4.6 (5.3) to 2.1 (8.3) degrees, p = 0.071 and in group 2 from 17.2 (4.9) to 9.6 (9.3), p = 0.001. There was no statistical difference between groups in pre-post improvement of GDI or other variables, except GMFM-D.

CONCLUSIONS

Relative mild to moderate preoperative knee flexion contracture does not influence the short-term improvement of gait after orthopedic surgery in children with bilateral CP.

Comparison between semitendinosus transfer to distal femur and medial hamstrings surgical lengthening for treatment of flexed knee gait in cerebral palsy

PURPOSE

Hamstrings surgical lengthening (HSL) has been frequently used for the treatment of flexed knee gait in cerebral palsy; however, recurrence of knee flexion deformity (KFD) and increase of anterior pelvic tilt (APT) were reported in a long-term follow-up.

RESEARCH QUESTION

The aim of this study was to compare semitendinosus transfer to distal femur (STTX) and semitendinosus surgical lengthening (STL) regarding the reduction of KFD and the increase of APT after flexed knee gait treatment.

METHODS

One hundred and eleven patients were evaluated and they were divided into two groups according to surgical procedures at knees: group A (65 patients/130 knees), including patients who received medial HSL as part of multilevel approach; group B (46 patients/92 knees), represented by patients who underwent orthopedic surgery including an STTX instead of STL.

RESULTS

Fixed knee flexion deformity (FKFD) decreased only in group B (from 6.79° to 2.96°, p < 0.001) after intervention. In kinematics, APT increased from 16.38° to 19.03° in group A (p = 0.003), while group B also increased from 15.26° to 20.59° (p < 0.001). The minimum knee flexion in stance phase (MKFS) reduced from 25.34° to 21.65° (p = 0.016) in group A and from 31° to 19.57° (p < 0.001) in group B. In the comparison between groups A and B, the increase of APT (p = 0.028) and reduction of FKFD (p < 0.001), popliteal angle (p = 0.001), bilateral popliteal angle (p = 0.003) and MKFS (p = 0.006) were higher after STTX than STL.

CONCLUSION

In the present study, patients who received STTX exhibited more improvement of knee extension at clinical examination and during gait than those who underwent to STL; however, STTX was not effective to prevent the increase of APT after flexed knee gait treatment.

Orthopaedic management of knee joint impairment in cerebral palsy: A systematic review and meta-analysis

BACKGROUND

The optimal management of impaired knee joint function in patients with cerebral palsy (CP) remains a significant and ongoing challenge in paediatric orthopaedic surgery.

RESEARCH QUESTION

What are the clinical and functional outcomes after operative and non-operative orthopaedic interventions for knee joint impairment in patients with CP?

METHODS

This systematic review and meta-analysis of orthopaedic interventions for the management of knee joint impairment in paediatric CP patients evaluated study-level data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. We performed searches of the following electronic databases from their dates of inception to November 2019: Medline (Ovid), Embase (Ovid) and Pubmed. We extracted mean differences in pre-operative and post-operative measurements for the following outcomes: minimum knee flexion in stance; knee flexion at initial contact; maximum knee flexion in swing; range of motion; popliteal angle; fixed flexion deformity angle; and mean pelvic tilt.

RESULTS

Sixty-nine retrospective cohort studies, prospective cohort studies and RCTs comprising 2991 patients were included with 4578 knees analysed. Included studies were of sufficient quality as assessed by the MOOSE checklist. Operative interventions showed significant improvement in knee flexion at initial contact, knee flexion in stance, range of motion, popliteal angle and fixed flexion deformity which were comparable when subgrouped according to operative technique. In contrast, non-operative techniques and botulinum toxin injection did not confer significant improvements. Operative interventions for knee joint impairment led to increased mean pelvic tilt and reduced maximum knee flexion in swing.

SIGNIFICANCE

This review provides strong evidence that operative interventions for the management of knee joint impairment in cerebral palsy patients improve knee kinematics and clinical examination findings.

Surgical outcomes after single event multilevel surgery in cerebral palsy patients with mid-stance knee hyperextension

BACKGROUND

Some patients with cerebral palsy (CP) exhibit excessive knee flexion at initial contact followed by knee hyperextension (KE) in mid-stance.

RESEARCH QUESTION

This study investigated the change in sagittal kinematics after distal hamstring lengthening (DHL) and triceps surae lengthening procedures in CP patients with KE, and compared it to those without KE. In addition, the risk factors for the worsening of postoperative KE were analyzed.

METHODS

Consecutive 312 patients (596 limbs) with CP who underwent DHL and triceps surae lengthening were included. All patients underwent preoperative and 1-year postoperative three-dimensional gait analysis. Patients' limbs were divided into the KE and knee flexion (KF) groups, according to preoperative minimum knee flexion in stance. KE was defined as minimum knee flexion in stance less than 0°.

RESULTS

The KE and KF groups included 130 and 466 limbs, respectively. Knee and ankle sagittal kinematics significantly improved after surgery in both groups. Minimum knee flexion in stance significantly increased from -6.6˚ to 0.5˚ in the KE group, but decreased from 14.6˚ to 7.8˚ in the KF group. Among the KE group, minimum knee flexion in stance improved in 103 limbs (79.2 %), but worsened in 27 limbs (20.8 %). Degree of preoperative KE was the only factor significantly associated with postoperative worsening of KE (p=0.002). The cutoff value for the worsening of KE was -5.8˚ of preoperative minimum knee flexion in stance.

SIGNIFICANCE

This study demonstrated that the sagittal kinematics of the knee and ankle joints improved after DHL and triceps surae lengthening procedures in CP patients with and without KE. Preoperative degree of KE was a risk factor for the worsening of KE after surgery. Therefore, careful selection for indication of DHL is required to prevent postoperative KE due to overlengthening of the hamstrings, particularly in patients with severe preoperative KE.

Hamstring lengthening in females with cerebral palsy have greater effect than in males

Children with spastic diplegia cerebral palsy often demonstrate crouched gait patterns, and typically undergo hamstring lengthenings. The objective of this retrospective study was to determine if the surgical response to medial and lateral hamstring lengthenings is different between males and females. Preoperative and postoperative kinematic data of 109 (71 males and 38 females) patients with cerebral palsy were evaluated. Females demonstrated larger decreases in popliteal angle, larger decreases in mid-stance knee flexion, and higher incidences of knee hyperextension postoperatively. Results indicate that females have larger responses to hamstring lengthenings than males.

The increase of anterior pelvic tilt after semitendinosus transfer to distal femur in patients with spastic diplegic cerebral palsy

The aim of this study was to compare semitendinosus transfer to distal femur (STTX) to semitendinosus surgical lengthening (STL) regarding the increase of anterior pelvic tilt after flexed knee gait treatment. Thirty-nine patients were evaluated, and they were divided according surgical procedures at knees: STL group (22 patients/44 knees), which included patients who received medial hamstrings surgical lengthening as part of multilevel approach, and STTX group (17 patients/34 knees), which was represented by patients who underwent orthopedic surgery including a STTX instead of STL. In the present study, the mean anterior pelvic tilt increased in all groups after treatment and STTX was not effective to prevent it in a medium-term follow-up.

Pelvic Tilt Changes After Hamstring Lengthening in Children With Cerebral Palsy

BACKGROUND

Flexion deformity of the knee is a common presentation in children with cerebral palsy with hamstring surgery as an option for addressing this. However, concerns with regard to increased pelvic tilt have been raised. The purpose of this study was to compare preoperative and postoperative pelvic tilt after isolated hamstring lengthening versus combined hamstring lengthening and the influence of Gross Motor Function Classification System (GMFCS) levels on pelvic tilt.

METHODS

This retrospective study included 46 ambulatory children with cerebral palsy who had had open medial hamstring lengthening (mean age at surgery, 11 y 11 mo; SD, 2 y 11 mo; GMFCS I, 16; GMFCS II 20; GMFCS III 10). Twelve children underwent isolated surgery and 34 children underwent combined surgery. The isolated hamstring procedures could be combined with foot and/or ankle-level surgery, as only the hamstring procedure would affect the pelvic tilt. Combined surgery was defined as hamstring lengthening with other procedures performed at the knee or more proximally. The preoperative and postoperative 3-dimensional gait analysis data were evaluated in this study.

RESULTS

Both the isolated and combined hamstring lengthening groups showed no significant change in pelvic tilt ([INCREMENT]1.28, P=0.203; [INCREMENT]1.47, P=0.113, respectively). A significant change in pelvic tilt was seen in children functioning at GMFCS III ([INCREMENT]4.66, P=0.009) but not GMFCS I and II ([INCREMENT]0.37, P=0.718; [INCREMENT]0.48, P=0.697). Significant postoperative decreases in the knee flexion angle at initial contact were seen for both isolated ([INCREMENT]5.72, P=0.010) and combined hamstring lengthening ([INCREMENT]10.95, P<0.001).

CONCLUSIONS

Hamstring lengthening, for the majority of patients, did not lead to a clinically significant change in mean pelvic tilt and improved knee flexion angle at initial contact. Children who functioned at GMFCS level III had an increase in anterior pelvic tilt and caution should be exercised in this group.

STUDY DESIGN

Level IV evidence-case series.

Management of the Knee Problems in Spastic Cerebral Palsy

Two common knee problems in cerebral palsy are increased knee flexion during stance phase and reduced knee flexion during the swing phase of gait. We reviewed the recent literature and based on that, we formed this review. Hamstring spasticity, quadriceps weakness, soleus weakness, and lever-arm dysfunction are few factors which lead to increased knee flexion during stance phase. Rectus spasticity diminishes knee flexion in the swing. Resulting gait-stiff knee gait interferes with ground clearance. Both gait patterns result into esthetically poor gait and increased energy consumption. Knee flexion gait may lead to pain in the knee. Natural history of knee flexion gait suggests deterioration over time. In the early stage, these gait abnormalities are managed by nonoperative treatment. Cases in which nonoperative measures fail or advance cases need surgical treatment. Various variables which are taken into consideration before selecting a particular treatment option are described. We also present an algorithm for decision-making. Nonsurgical options and surgical procedures are discussed.

Effectiveness of surgical and non-surgical management of crouch gait in cerebral palsy: A systematic review

BACKGROUND

Cerebral palsy (CP) is a prevalent group of neuromotor disorders caused by early injury to brain regions or pathways that control movement. Patients with CP exhibit a range of functional motor disabilities and pathologic gait patterns. Crouch gait, characterized by increased knee flexion throughout stance, is a common gait pattern in CP that increases energy costs of walking and contributes to ambulatory decline. Our aim was to perform the first systematic literature review on the effectiveness of interventions utilized to ameliorate crouch gait in CP.

METHODS

Comprehensive searches of five medical databases yielded 38 papers with 30 focused on orthopaedic management.

RESULTS

Evidence supports the use of initial hamstring lengthenings and rectus femoris transfers, where indicated, for improving objective gait measures with limited data on improving gait speed or gross motor function. In contrast, evidence argues against hamstring transfers and revision hamstring lengthening, with recent interest in more technically demanding corrective procedures. Only eight studies evaluated alternatives to surgery, specifically strength training, botulinum toxin or orthoses, with inconsistent and/or short-lived results.

CONCLUSIONS

Although crouch in CP is recognized clinically as a complex multi-joint, multi-planar gait disorder, this review largely failed to identify interventions beyond those which directly address sagittal plane knee motion, indicating a major knowledge gap. Quality of existing data was notably weak, with few studies properly controlled or adequately sized. Outcomes from specific procedures are confounded by multilevel surgeries. Successful longer term strategies to prevent worsening of crouch and subsequent functional decline are needed.

LEVEL OF EVIDENCE

Systematic review.

Cerebral palsy

Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts and management strategies currently focus on the needs of children. Clinical management of children with cerebral palsy is directed towards maximizing function and participation in activities and minimizing the effects of the factors that can make the condition worse, such as epilepsy, feeding challenges, hip dislocation and scoliosis. These management strategies include enhancing neurological function during early development; managing medical co-morbidities, weakness and hypertonia; using rehabilitation technologies to enhance motor function; and preventing secondary musculoskeletal problems. Meeting the needs of people with cerebral palsy in resource-poor settings is particularly challenging.

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.

The effects of surgical lengthening of hamstring muscles in children with cerebral palsy--the consequences of pre-operative muscle length measurement

Children with cerebral palsy often undergo multiple orthopaedic surgical procedures in a single episode. Evidence of the effectiveness of individual components within the overall package is sparse. The introduction of musculoskeletal modelling in Oswestry has led to a more conservative management approach being taken with hamstring muscles for children walking in a degree of crouch. Muscles which were shown to be of at least normal length at initial contact were not surgically lengthened, as would have been the case previously. A retrospective review of 30 such patients was therefore possible, comparing 15 patients treated before the policy change who had their hamstrings lengthened with 15 treated after who did not. All patients had pre and post operative gait assessments and significant changes were observed for each group separately and for the two groups when compared. The comparison revealed that preserving the hamstrings does tend to reduce, and therefore normalize, the dynamic muscle length. Examination of the two patient groups separately, however, reveals a more complex picture with more global gait improvements seen when the hamstrings were lengthened. No absolute recommendation can be made to inform the clinical management of all children with normal to long hamstring muscles during gait. The final decision of whether to include a hamstring lengthening will need to take into account the characteristics of the individual child.

Explaining the variability improvements in gait quality as a result of single event multi-level surgery in cerebral palsy

PURPOSE

This is a study of all children with spastic diplegic cerebral palsy (Gross Motor Classification System levels II and III) who had single event multi-level surgery (SEMLS) at a single tertiary referral hospital between 1995 and 2008 to identify factors predicting improvement in gait quality as quantified by the gait profile score (GPS). 9 factors (5 dichotomous and 4 continuous, including preoperative GPS) that might be expected to predict outcomes were identified and univariate and multivariable analysis used to explore how these affected outcomes.

SCOPE

Data from 121 children were included. The mean improvement in GPS of 4.3° was 2.7 times the minimal clinically important difference. Univariate analysis suggested that preoperative GPS is a very strong predictor of improvement in GPS (p<10(-5)) and when this is considered as a covariate only GMFCS level (p=10(-5)) and having had previous surgery (p=0.026) were found to be statistically significant predictors of GPS improvement (p<0.05). Children of GMFCS level II improved on average by 2° more than those of level III once differences in preoperative GPS had been accounted for.

CONCLUSION

Children with the most abnormal gait patterns preoperatively, and hence those with the most potential to improve are those that improve the most and surgery has clearly been beneficial. Over a quarter of children show changes in GPS which were less than the MCID. The majority of these were those with the least abnormal gait patterns preoperatively and further research is required to establish whether and how such children benefit from SEMLS.

Long term outcome of single event multilevel surgery in spastic diplegia with flexed knee gait

Distal hamstring lengthening (DHL) is a commonly performed procedure in flexed knee gait. However, the necessity of this procedure has been challenged due to the concerns on adverse effects in long-term follow-up. This retrospective study was undertaken to investigate the long-term outcome of single event multilevel surgery (SEMLS), including bilateral DHL, in ambulatory patients with cerebral palsy using 3D gait analysis. Twenty-nine ambulatory patients with spastic diplegic cerebral palsy who had undergone SEMLS including bilateral DHL were included. 3D gait analysis was performed preoperatively, 1 year postoperatively and over 10 years postoperatively. Preoperative temporal parameters, kinematics and GDI were compared with values obtained 1 and 10 year follow-up visits. The mean age of patients at time of first surgery was 8.3 years (range, 5.4-16.3 years), and mean time from first surgery to last 3D gait analysis was 11.8 years (range, 10.0-13.3 years). Mean pelvic tilt was not changed significantly after SEMLS including DHL. Mean knee flexion at initial contact decreased from 31.1° preoperatively to 26.0° at 1 year postoperatively (p=0.065), and then decreased significantly to 23.6° at 10 years postoperatively (p=0.038) versus the preoperative value. Mean GDI score significantly improved from 69.4 preoperatively to 77.9 at 1 year postoperatively (p=0.003) and continuously improved to 82.2 at 10 years postoperatively (p=0.017). Single event multilevel surgery including DHL provides a favorable outcome 10 years postoperatively in patients with spastic diplegic cerebral palsy.

Long-term effects after conversion of biarticular to monoarticular muscles compared with musculotendinous lengthening in children with spastic diplegia

Adverse effects such as increased anterior pelvic tilt (APT) are reported after muscle-tendon lengthening (MTL) for the correction of flexed knee gait in cerebral palsy. The conversion of biarticular muscles (CBM) to monoarticular muscles represents an alternative treatment, but only few short-term results have been published, without comparison with MTL. The long-term outcome of 21 diplegic patients treated with CBM in a prospective study was compared with the results in MTL patients in a matched-pair analysis. Standardized clinical examination and three-dimensional gait analysis were done before surgery, 1 year thereafter, and at long-term follow-up a mean of 9.2 years postoperatively. Mean APT increased one year after surgery in both groups. This increase was higher in MTL patients and statistically significant only for this group. Knee flexion at initial contact and minimum knee flexion in stance were significantly decreased in both groups, while in swing the CBM group tended to show more of a decrease in knee flexion but at the cost of reduced peak flexion. Both groups showed deterioration of kinematic knee parameters through to long-term follow-up; the favourable effects of CBM disappeared, and the two groups displayed comparable average pelvic and knee kinematics. Considering individual patterns the prevalence of increased APT was lower in the CBM group 1 year after surgery, indicating that sparing the semitendinosus may have a positive effect on pelvic stability. However, after 9 years 30% of the patients in both groups showed increased APT indicative of persistent hamstring insufficiency. These results demonstrate that CBM, a significantly more extensive procedure, has no long-term advantage over MTL.

Are results after single-event multilevel surgery in cerebral palsy durable?

BACKGROUND

Gait and function may deteriorate with time in patients with spastic diplegia. Single-event multilevel surgery often is performed to either improve gait or prevent deterioration. However it is unclear whether the presumed gait improvements are durable.

QUESTIONS/PURPOSES

We therefore determined whether (1) single-event multilevel surgery improves gait in patients with spastic diplegia and (2) whether the improved function is durable.

METHODS

We retrospectively reviewed the data of 14 patients with spastic diplegia. At the time of surgery, one patient had gross motor Level I function, 10 patients had Level II function, and three patients had Level III function. There were four females and 10 males with a mean age of 13 years (range, 7-18 years). The mean number of orthopaedic procedures per single-event multilevel surgery session was 7.4 ± 2.8 (median, 6.5; range, 4-15). We used instrumented gait analysis to determine joint ROM, movement analysis profiles, and the gait profile score. The minimum followup was 1 year (mean, 2 years; range, 1-3 years).

RESULTS

At last followup, movement analysis profiles for knee flexion, for ankle dorsiflexion, and for foot progression improved as did the gait profile score. Additional surgery after the index procedure was performed in nine of the 14 patients because of relapse of the original or new gait problems. Major surgical adverse events occurred in one of the 14 patients.

CONCLUSIONS

Severe gait dysfunction in patients with spastic diplegia can be improved short-term in one operative session by single-event multilevel surgery, but to preserve the early improvements many patients require additional surgery. It is unknown whether the improvements will last for decades.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

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.

Management of the knee in spastic diplegia: what is the dose?

This article discusses the sagittal gait patterns in children with spastic diplegia, with an emphasis on the knee, as well as the concept of the "dose" of surgery that is required to correct different gait pathologies. The authors list the various interventions in the order of their increasing dose. The concept of dose is useful in the consideration of the management of knee dysfunction.

Selective percutaneous myofascial lengthening of the lower extremities in children with spastic cerebral palsy

Children with spastic cerebral palsy commonly acquire lower extremity musculoskeletal deformities that at some point may need surgical correction. The authors present 58 children with spastic cerebral palsy who underwent selective percutaneous myofascial lengthening of the hip adductor group and the medial or the lateral hamstrings. All the patients were spastic diplegic, hemiplegic, or quadriplegic. The indications for surgery were a primary contracture that interfered with the patients' walking or sitting ability or joint subluxation. Gross motor ability and gross motor function of the children were evaluated using the gross motor function classification system (GMFCS) and the gross motor function measure (GMFM), respectively. The mean time of the surgical procedure was 14 minutes (range, 1 to 27 minutes). All patients were discharged from the hospital setting the same day after the operation. There were no infections, overlengthening, nerve palsies, or vascular complications. Three patients required repeat procedures for relapsed hamstring and adductor contractures at 8, 14, and 16 months postoperatively. At 2 years after the initial operation, all the children improved on their previous functional level; 34 children improved by one GMFCS level, and 5 children improved by two GMFCS levels. The overall improvement in mean GMFM scores was from 71.19 to 83.19.

Long-term physical therapy management following a single-event multiple level surgery

PURPOSE

This case report provides an overview of surgical procedures, including single-event multiple level surgery (SEMLS) used in the management of secondary conditions in cerebral palsy (CP). Physical therapy (PT) management over 35 months following SEMLS is described for an adolescent (Gross Motor Function Classification System level II) with CP.

SUMMARY OF KEY POINTS

When conservative management is not sufficient to manage secondary complications, SEMLS, combined with PT and family support, may provide the foundation for greater functional improvement than surgical correction of a single impairment. The outcome measures used following SEMLS included the Gross Motor Function Measure-66, Activity Scale for Kidsperformance38, goniometry, manual muscle testing, and Numerical Pain Rating Scale.

STATEMENT OF CONCLUSIONS

Preoperative functional level can be exceeded and sustained beyond 24 months following surgery.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Rehabilitation following a SEMLS requires teamwork and a long-term commitment to maximize outcomes.

Nerve palsy after hamstring lengthening in patients with cerebral palsy

BACKGROUND

The purpose of this study was to assess the incidence of, risk factors for, and treatment of nerve palsy after hamstring lengthening in children with cerebral palsy.

METHODS

A medical record review of patients with cerebral palsy who had hamstring lengthening between 1994 and 2005 was performed. Data included the preoperative popliteal angle, the presence of a knee flexion contracture, postoperative pain management, and type of immobilization. The presence of postoperative nerve palsy was established based on the recording of numbness, loss of motor function in the foot, or hypersensitivity of the foot in the inpatient record or the postoperative clinic notes. The need for medical management and time to resolution of symptoms were noted.

RESULTS

A total of 292 children underwent 329 hamstring lengthening surgeries. The mean age at surgery was 9.5 years (range, 2.5-18 years). Twenty-eight patients (9.6%) experienced postoperative nerve palsy. Time to recognition of the palsy ranged from 4 hours to 72 days. Patients diagnosed within 24 hours had loss of motor function and/or lack of sensation of the toes. Patients diagnosed from 8 to 72 days postoperatively had dysesthesias of the feet. Treatment of early palsies consisted of the removal of immobilization, bivalving of casts, or wedging casts into flexion. Fourteen of 28 patients were treated with Neurontin. Twenty-two of 25 patients with adequate follow-up recovered nerve function. Older children, noncommunicative patients, nonambulatory patients, and those who had epidural pain management were at statistically significant higher risk for postoperative palsy. The trend for palsies in spastic quadriplegic patients and after repeat lengthening procedures did not reach significance. There was no significant relationship between popliteal angle or the presence of a knee flexion contracture and development of nerve palsy.

CONCLUSIONS

Nerve palsy occurred in 9.6% of patients undergoing hamstring lengthening. Although the greatest risk was in noncommunicative adolescents who were nonambulatory, a small number of younger ambulatory patients developed palsies as well, so that all patients must be considered at risk. Vigilance in patients with epidural pain control to avoid excessive hip flexion and/or knee extension is warranted. Treatment is immediate knee flexion. Resolution of symptoms occurred in 82.1% of patients.

The outcome of surgical intervention for early deformity in young ambulant children with bilateral spastic cerebral palsy

We reviewed the outcome in 24 children with bilateral spastic cerebral palsy aged seven years or younger for whom surgery was recommended between 1999 and 2005 following gait analysis. A total of 13 children (operative group) had surgery and the remaining 11 (control group) did not, for family or administrative reasons. The operative group had at least two post-operative gait analyses at yearly intervals, with eight children having a third and six children a fourth. The control group had a second analysis after a mean interval of 1.5 years (95% confidence interval 1.1 to 1.9). In the operative group, the Gillette gait index, the ranges of movement in the lower limb joint and knee extension in stance improved following surgery, and this was maintained overall at the second post-operative analysis. The minimum knee flexion in stance in the control group increased between analyses.

These results suggest that surgical intervention in selected children can result in improvements in gait and function in the short to medium term compared with non-operative management.

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.

Assessment of mobility after multi-level surgery for cerebral palsy

In cerebral palsy, the site and severity of the brain lesion are directly linked to gross motor function and the development of musculoskeletal deformities. The relationship between walking ability and orthopaedic surgery in children with cerebral palsy is not fully understood. The development of new tools such as the Functional Assessment Questionnaire and the Functional Mobility Scale can be used to give new insights on the functional impact of multilevel surgery. These scales are most useful as part of systematic, long-term follow-up.