Recurrence of hip instability after reconstructive surgery in patients with cerebral palsy

Treatment of Hip Displacement in Children With Cerebral Palsy: A 5-year Comparison of Proximal Femoral Osteotomy and Combined Femoral-Pelvic Osteotomy in 163 Children

BACKGROUND

This study compared the 5-year outcomes of isolated proximal femoral varus osteotomy (FO) and combined proximal femoral varus and pelvic osteotomy (FPO) for the treatment of hip displacement in children with cerebral palsy (CP) in Sweden, focusing on the number of reoperations and residual hip displacement.

METHODS

The study included 163 children with a 5-year follow-up after FO or FPO in the national Swedish CP surveillance program, CPUP. Descriptive statistics and univariate and multivariate Cox regression analyses were used to identify whether the age at surgery, sex, Gross Motor Function Classification System level, CP dominant symptom, hip migration percentage (MP), type of surgery (unilateral/bilateral), and history of soft tissue hip surgery were related to the 5-year outcomes after surgery. Failure after hip surgery was defined as a skeletal reoperation involving the hip and/or MP >50%.

RESULTS

During the period 2001 to 2017, 163 children (65 girls) underwent 246 femoral and/or pelvic osteotomies (154 FO, 47 bilaterally; 92 FPO, 16 bilaterally) and had a 5-year follow-up; 95 and 74 children had ≥1 FO or FPO as the primary skeletal surgery, respectively. The mean preoperative MP (51%±18% for FO and 59%±17% for FPO, P =0.001) and age at surgery (6.2±2.5 years for FO and 7.3±2.8 years for FPO, P =0.014) differed between procedures. At the 5-year follow-up, 5 hips (5%) had reoperations and 5 hips (5%) had radiological failure among the 92 FPOs, and 33 (21%) had reoperations and 14 (9%) radiological failure among the 154 FOs. The difference in outcome failure rate was significant ( P <0.001). Multivariate Cox regression analysis showed a lower risk for failure with FPO [hazard ratio (HR)=0.32, 95% CI: 0.15-0.68] compared with FO. A higher preoperative MP increased the risk for outcome failure (HR=1.21, 95% CI: 1.15-1.36 for each 5% increment).

CONCLUSIONS

FPO had a higher mean preoperative MP but a lower 5-year outcome failure rate compared with FO. A higher preoperative MP was associated with an increased risk of failure.

LEVEL OF EVIDENCE

Level II-prospective comparative study.

Hip reconstruction in cerebral palsy: Lessons from a single center and 137 hips

Background

This large, retrospective, single-center study aimed to compare the outcomes of unilateral hip reconstruction and bilateral hip reconstruction in children with non-ambulatory cerebral palsy and ascertain risk factors for recurrent instability and reoperation.

Method

We performed a retrospective review of 137 hip reconstructions performed for patients with cerebral palsy. Preoperative and postoperative clinical and radiological parameters were documented, including hip migration percentage, acetabular index, the Gross Motor Function Classification System, the Melbourne Cerebral Palsy Hip Classification System, hip abduction, and pelvic obliquity.

Results

Overall, 49 patients underwent bilateral hip reconstruction, and 37 patients underwent unilateral hip reconstruction. In the unilateral hip reconstruction group, the reconstructed hip remained stable (with a migration percentage < 33%) in 59% of patients compared to 74.4% of the more affected hips in the bilateral hip reconstruction group (p = 0.02). Of the unreconstructed hip in the unilateral hip reconstruction group, 74.4% remained stable (with a migration percentage < 33%), compared to 78.8% of the less affected hips in the bilateral hip reconstruction group. A level pelvis was maintained at final follow-up in significantly more patients in the bilateral hip reconstruction group than the unilateral hip reconstruction group (p = 0.002). Further surgical intervention was performed in 41% of the unilateral hip reconstruction group, compared with 11.5% in the bilateral hip reconstruction group (p = 0.001). Surgery performed under the age of 8 years and not performing an acetabular osteotomy were found to be risk factors for recurrent instability in all groups.

Conclusion

Our series suggests that in terms of recurrent instability after hip reconstruction in cerebral palsy, protective factors against this complication include bilateral hip reconstruction, hip reconstruction after 8 years of age, and the use of an acetabular osteotomy.

Hip subluxation in Italian cerebral palsy children and its determinants: a retrospective cohort study

The study's aim was two-fold: to describe the trend of hip subluxation in the largest sample of Italian nonambulatory cerebral palsy (CP) children ever published; to investigate its determinants. This single-centre retrospective cohort study included patients with spastic or dyskinetic CP, Gross Motor Function Classification System (GMFCS) level IV or V, age 0-18 years, having been referred to our unit before March 2020. The hip subluxation was measured by means of the migration percentage (MP). Other data were gathered such as sex, CP subtype, GMFCS level, presence of drug-resistant epilepsy, age, use of walkers with weight relief or standing devices, previous botulinum injection or hip surgery, oral or intrathecal baclofen and hip pain. Multiple linear stepwise regression was performed and descriptive statistics are provided. Spastic CP had MP maximum increase in early ages, with GMFCS level V values persistently higher than level IV. The dyskinetic subtype showed a slower increase of the MP, with GMFCS level IV presenting similar or higher values, compared to level V. Age, CP severity and spastic subtype are the main determinants. The stepwise multiple regression analysis demonstrated that weight relief walking and standing assistive devices, combined with botulinum contributed to reduce the MP progression. Dyskinetic CP showed overall lower MP values and a more variable behaviour relative to age and GMFCS level, compared to the spastic subtype. Standing and walking assistive devices, with partial or total weight relief, combined with individually targeted botulinum injections, should be considered in the management of bilateral nonambulatory CP patients, to prevent hip subluxation or its recurrence after surgery.

Can Over-containment Prevent Recurrence in Children With Cerebral Palsy and Hip Dysplasia Undergoing Hip Reconstruction?

INTRODUCTION

Hip reconstruction is often necessary in children with cerebral palsy (CP) but is associated with high failure rates. Over-containment deeply seats the hip within the acetabulum at the time surgical reconstruction. The goal of this study is to evaluate the effect of over-containment on radiographic outcomes and failure rates in children with CP undergoing hip reconstruction.

METHODS

This study is a retrospective chart review of children with CP that underwent hip reconstruction between 2010 and 2019 with at least 2 years of radiographic follow-up. Migration percentage (MP), acetabular index (AI), and neck shaft angle (NSA) were recorded preoperatively, postoperatively and throughout follow-up. Failures were defined as a MP at latest follow-up ≥30% or need for revision hip reconstruction. Hips were divided into groups based on postoperative MP-group 1 (over-containment group) had a MP≤0% and group 2 had an MP>0%. Radiographic parameters and failure rates were compared across Gross Motor Functional Classification Score (GMFCS) level, age at the time of surgery, and degree of preoperative subluxation.

RESULTS

A cohort of 108 patients (197 hips) with an average age of 7.3±3.2 years met inclusion criteria with an average follow-up of 49.6 months (range: 24 to 118 mo). There were 147 hips in group 1 and 50 hips in group 2. At latest follow-up, group 1 demonstrated lower MP, AI, and NSA in comparison to group 2. The overall failure rate in our cohort was 8.1% (16 hips). Failure rates trended lowest in hips that were over-contained (6.1% v. 14.0%) although not statistically significant. Over-containment resulted in significantly lower failure rates in GMFCS IV/V hips, children under age 6 at the time of surgery and those with a higher degree of preoperative hip displacement (MP>50%).

CONCLUSIONS

Over-containment at the time of hip reconstruction can positively affect radiographic outcomes and failure rates in children with CP. Over-containment should be considered in hips at high risk of failure, especially non ambulatory children with significant hip subluxation at an early age.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Reconstructive hip surgery in children with cerebral palsy: factors influencing risk of femoral head avascular necrosis

Femoral head avascular necrosis (AVN) is a complication of hip reconstruction in children with cerebral palsy (CP) with uncertain incidence. The purpose of this study was to establish the rate of AVN in children undergoing hip reconstruction and to identify the factors associated with AVN. Medical records and radiographs of patients aged 1-18 with a diagnosis of CP who have undergone hip reconstruction over a 9-year period (2010-2018) with at least 1-year follow-up were reviewed. Age at time of surgery, sex, Gross Motor Function Classification System (GMFCS), procedure(s), preoperative migration percentage (MP), and signs of AVN on anterioposterior pelvis radiographs at routine follow-up visits (3 months, 6 months, and years 1-9, annually) according to the Bucholz-Ogden (BO) and Kalamchi-MacEwen (KM) classification systems were recorded. Univariate analysis was used to test for significance. Three hundred forty-nine hips in 209 patients met our inclusion criteria. Eleven hips (rate; 3%), in 11 patients, developed AVN. Classification of AVN was found to consist of: class I-4 (36%), class II-1 (9%), class III-[BO: 4 (36%)] [KM: 3 (27%)], and Class IV-[BO: 2 (18%)] [KM: 3 (27%)]. Average follow-up was of 3.5 years. The AVN cohort displayed older age (11.0 ± 2.8 vs. 8.1 ± 3.4; P = 0.005). Open reduction was associated with increased AVN, occurring in 9% of the hips (P = 0.004). No significant association was found between preoperative MP, GMFCS, or acetabular osteotomy. The method of open reduction (anterior vs. medial) was not significantly associated with AVN (P = 0.4471). In this large series, the observed rate of AVN was 3%, associated with open reductions at time of hip reconstruction. If possible, closed reduction would be preferred at time of hip reconstruction in children with CP to lower the risk of AVN. Level of evidence: III.

Failure of Hip Reconstruction in Children With Cerebral Palsy: What Are the Risk Factors?

BACKGROUND

The rates and risk factors contributing to failure after hip reconstruction among patients with cerebral palsy (CP) are not well established. In analyzing a large cohort of children with CP who underwent hip reconstruction, the objectives of this study are to establish (1) the failure rates and (2) associated risk factors.

METHODS

This retrospective study included chart and radiographic review of patients between the ages of 1 to 18, with a diagnosis of CP, who underwent a hip reconstructive procedure at a single children's hospital over a 9-year period (2010 to 2018). Patients without at least 2 years of follow-up were excluded. Age at time of surgery, sex, Gross Motor Function Classification System (GMFCS), procedure(s) performed, preoperative migration percentage (MP), neck-shaft angle, and acetabular index (AI) were recorded. Failure was defined as need for revision surgery or a MP >50% on follow-up radiographs. Logistic regression and multiple-variable regression-type models were used to test for significance of risk factors.

RESULTS

Of the 291 hips in 179 patients (102 males, 77 females) that met inclusion criteria, 38 hips (13%) failed. Significant differences in the failure group were seen in age at time of surgery (6.2±3.2 vs. 8.1±3.2; P<0.001), preoperative MP (62.3±28.7 vs. 39.9±24.1%; P<0.001) and preoperative neck-shaft angle (164.9±8.2 vs. 157.3±15.6 degrees; P<0.001). Age below 6 at time of surgery significantly increased failure rate (26% vs. 6.3%, P<0.001) as did preoperative MP >70% (28.9% vs. 9.9%, P<0.001). Receiving an acetabular osteotomy was protective against failure (9.1% vs. 16.9%, P=0.048), particularly in patients with a preoperative AI >25° (odds ratio=0.236; confidence interval: 0.090-0.549).

CONCLUSIONS

In this case series, failure after hip reconstruction for children with CP was determined to be 13.1%. There was a higher risk associated with age under 6 at time of surgery or a preoperative MP >70%. Correction of acetabular dysplasia when AI is more than 25 degrees with acetabular osteotomy at time of hip reconstruction, exerted a protective effect against subsequent failure.

LEVEL OF EVIDENCE

Level III-retrospective case series.

Quality of Surgery and Patient Selection Are Keys to Success in Hip Stabilization Surgery in Cerebral Palsy

BACKGROUND

Cerebral palsy patients are at risk of hip instability, to which various soft tissue and bony surgeries are performed should conservative management fail. We aim to identify factors associated with treatment failure to guide surgical management.

METHODS

Cerebral palsy patients treated at 2 university-affiliated tertiary pediatric orthopaedic referral centers with hip stabilization surgery performed for subluxation in 1998 to 2015 with minimum of 5 years follow-up were reviewed. Failure was defined as reoperation to the same hip because of recurrent subluxation. Age, sex, Gross Motor Function Classification System level, tone abnormality, operation type, Reimer's migration index (RMI), and acetabular index (AI) were assessed. Cut-off values were identified through Youden index on receiver operating characteristic curve.

RESULTS

Eighty-nine hips from 55 patients with mean follow-up of 12.4 years were analyzed. Revision surgery was performed in 14 hips. Postoperative hip subluxation (P<0.001) and acetabular dysplasia (P=0.001) were predictive of failure, with postoperative RMI conferring an adjusted hazard ratio of 1.13 (95% confidence interval: 1.08-1.19, P<0.001) on multivariable survival analysis. Achieving a postoperative RMI of <27.5% predicts success with 92.9% sensitivity and 72% specificity with area under curve of 0.916 (P<0.001), while postoperative AI of <23.1 degrees predicts success with 92.3% sensitivity and 62.2% specificity with area under curve of 0.796 (P=0.001). In subgroup analysis of soft-tissue-only procedures, RMI >44% preoperative and >32% postoperative were associated with reoperation. In femur-only osteotomies, preoperative RMI >48% and postoperative RMI >28% were associated with failure. In pelvic and combined osteotomies, postoperative RMI >32% and AI >30 degrees were associated with failure. Other factors analyzed were not associated with reoperation.

CONCLUSIONS

Patient selection and quality of surgery in terms of residual postoperative hip subluxation and acetabular dysplasia are associated with need for remedial surgery. Soft-tissue-only procedures should aim to correct RMI to <32%. Bony surgery should be considered when preoperative RMI >44%, and pelvic osteotomies if RMI >48%. Pelvic osteotomies should target postoperative RMI <32% and AI <30 degrees.

LEVEL OF EVIDENCE

Level II-prognostic study.

Blood Loss and Related Laboratory Changes after Single-Event Multilevel Surgery and Hip Reconstructive Surgery in Patients with Cerebral Palsy

Backgroud

Single-event multilevel surgery (SEMLS) and hip reconstructive surgery (HRS) often cause intraoperative bleeding, consequently increasing the probability of transfusion and postoperative laboratory changes. Therefore, it is important to assess risk factors to predict the amount of blood loss. This study aimed to evaluate blood loss, its influencing factors, and the related laboratory changes during SEMLS and HRS in patients with cerebral palsy (CP).

Methods

We retrospectively examined consecutive CP patients who underwent SEMLS and HRS. Surrogate markers of blood loss, including preoperative and postoperative hemoglobin (Hb), hematocrit, and changes in Hb concentration, were assessed. Albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine levels were also analyzed for related laboratory changes. Risk factors were analyzed using multiple regression and logistic regression models.

Results

The overall cohort comprised 1,188 patients. Of them, 1,007 and 181 underwent SEMLS and HRS, respectively. Furthermore, 72 of 181 patients underwent a concomitant Dega osteotomy. The regression model showed that low preoperative Hb concentration (p < 0.001), high albumin level (p = 0.007), low body mass index (BMI) (p = 0.002), and bilateral HRS (p < 0.001) were significant risk factors of postoperative anemia. Valproate medication was associated with Hb drop, and the risk factors for Hb level < 8 g/dL on postoperative day 2 were bilateral HRS and Dega osteotomy in the HRS subgroup. In total, 21.6% had elevated AST levels on postoperative day 2, and bilateral HRS (p < 0.001), Gross Motor Function Classification System (GMFCS) level V (p = 0.041), Dega osteotomy (p < 0.001), and high preoperative AST level (p < 0.001) increased the risk of AST elevation.

Conclusions

We have summarized the estimated blood loss and related laboratory changes after SEMLS and HRS in patients with CP and identified the risk factors. Clinical guidelines should be accordingly developed to include assessment of these risk factors and their impact in the outcomes of CP patients undergoing SEMLS and HRS.

Management of Hip Disorders in Patients with Cerebral Palsy

Hip disorders are the second most common musculoskeletal abnormality seen in children with cerebral palsy, affecting nearly 1 in 3. The goal of surgical intervention is to provide a mobile, located, and painless hip. Reconstructive procedures are indicated for children with migration percentages of >40%. Reconstructive procedures typically result in a long-term satisfactory outcome, although recurrence is seen particularly in nonambulatory children and when the reconstruction is performed earlier than 6 years of age. Salvage procedures are performed when reconstructive procedures are no longer an option and degenerative changes have occurred. They include proximal femoral valgus osteotomy, proximal femoral resection, and hip arthroplasty.

Outcome of Femoral Varus Derotational Osteotomy for the Spastic Hip Displacement: Implication for the Indication of Concomitant Pelvic Osteotomy

No previous studies have suggested a reliable criterion for determining the addition of a concomitant pelvic osteotomy by using a large patient cohort with quadriplegic cerebral palsy and a homogenous treatment entity of femoral varus derotational osteotomies (VDRO). In this retrospective study, we examined our results of hip reconstructions conducted without a concomitant pericapsular acetabuloplasty in patients with varying degrees of hip displacement. We wished to investigate potential predictors for re-subluxation or re-dislocation after the index operation, and to suggest the indications for a simultaneous pelvic osteotomy. We reviewed the results of 144 VDROs, with or without open reduction, in 72 patients, at a mean follow-up of 7.0 (2.0 to 16.0) years. Various radiographic parameters were measured, and surgical outcomes were assessed based on the final migration percentage (MP) and the Melbourne Cerebral Palsy Hip Classification Scale (MCPHCS) grades. The effects of potential predictive factors on the surgical outcome was assessed by multivariate regression analysis. A receiver operating characteristic (ROC) curve analysis was also performed to determine whether a threshold of each risk factor existed above which the rate of unsatisfactory outcomes was significantly increased. In total, 113 hips (78.5%) showed satisfactory results, classified as MCPHCS grades I, II, and III. Thirty-one hips (21.5%) showed unsatisfactory results, including six hip dislocations. Age at surgery and preoperative acetabular index had no effects on the results. Lower pre- and postoperative MP were found to be the influential predictors of successful outcomes. The inflection point of the ROC curve for unsatisfactory outcomes corresponded to the preoperative MP of 61.8% and the postoperative MP of 5.1%, respectively; these thresholds of the pre- and postoperative MP may serve as a guideline in the indication for a concomitant pelvic osteotomy. Our results also indicate that the severely subluxated or dislocated hip, as well as the hip in which the femoral head is successfully reduced by VDRO but is still contained within the dysplastic acetabulum, may benefit from concomitant pelvic osteotomy.

Neglected femoral neck fractures in cerebral palsy: a narrative review

Hip fractures are severe conditions with a high morbidity and mortality, especially when the diagnosis is delayed, and if formulated over 30 days after the injury, is termed a 'neglected femoral neck fracture' (NFNF).Cerebral palsy (CP) is probably one of the major risk factors for NFNF in Western countries, mainly because of both cognitive and motor impairments. However, considering the high prevalence of fractures in these patients, the incidence of NFNF in this population is probably underestimated, and this condition might result in persistent hip or abdominal pain.Several techniques are available for the treatment of NFNF (i.e. muscle pedicle bone graft, fixation with fibular graft, valgisation osteotomy), but most of them could affect motor function.Motor function must be preserved for as long as possible, in order to enhance the quality of life of CP patients.After discussing published NFNF cases in CP patients and available treatment options, a practical approach is proposed to facilitate the orthopaedic surgeon to both early identify and appropriately manage these challenging fractures. Cite this article: EFORT Open Rev 2020;5:58-64. DOI: 10.1302/2058-5241.5.190019.

Guided Growth of the Proximal Femur for the Management of Hip Dysplasia in Children With Cerebral Palsy

BACKGROUND

Progressive hip displacement is one of the most common and debilitating deformities seen in children with cerebral palsy (CP). The aim of this study was to evaluate the results of temporary medial hemiepiphysiodesis of the proximal femur (TMH-PF) using a transphyseal screw to control hip migration during growth in children with CP.

METHODS

This was a retrospective study of children with CP and hip dysplasia, age 4 to 11 years and GMFCS levels III-V. There were 28 patients with 56 hips that underwent TMH-PF surgery between 2007 and 2010. Clinical and radiologic evaluation was performed preoperatively, at 6, 12, and 60 months following the index surgery. Acetabular index (AI), neck-shaft angle (NSA) and migration percentage (MP) were measured. All complications were recorded.

RESULTS

All radiographic measurements were significantly improved at the final follow-up. Positive correlations were found between NSA, MP, and AI. Multiple regression analysis revealed that MP, time from surgery, and age were influenced by the decrease of the NSA. The femoral physis grew off the screw in 9 hips within 36 months. The screw head broke during attempted screw exchange in 1 hip. The remain cases (4 hips) were treated by placing a second screw parallel to the existing one. Finally, progressive subluxation occurred in 3 hips when the physis grew off the screw and were treated by skeletal reconstruction.

CONCLUSIONS

TMH-PF was effective in controlling progressive subluxation of the hip in the majority of cases, obviating the need for major reconstructive surgery in these children with CP.

LEVEL OF EVIDENCE

Level IV.

Use of iliac crest allograft for Dega pelvic osteotomy in patients with cerebral palsy

Background

Dega pelvic osteotomy is commonly performed procedure in patients with cerebral palsy (CP) undergoing hip reconstructive surgery for hip displacement. However, there has been no study investigating the outcomes after Dega pelvic osteotomy using allograft in patients with CP. This study investigated the outcomes of Dega pelvic osteotomy using iliac crest allograft in CP with hip displacement and the factors affecting allograft incorporation.

Methods

This study included 110 patients (150 hips; mean age 8y7mo; 68 males, 42 females) who underwent hip reconstructive surgeries including Dega pelvic osteotomy using iliac crest allograft. To evaluate the time of allograft incorporation, Goldberg score was evaluated according to the follow-up period on all postoperative hip radiographs. The acetabular index, migration percentage, and neck-shaft angle were also measured on the preoperative and postoperative follow-up radiographs.

Results

The mean estimated time for allograft incorporation (Goldberg score ≥ 6) was 1.1 years postoperatively. All hips showed radiographic union at the final follow-up and there was no case of graft-related complications. Patients with Gross Motor Function Classification System (GMFCS) level V had 6.9 times higher risk of radiographic delayed union than those with GMFCS level III and IV. Acetabular index did not increase during the follow-up period (p = 0.316).

Conclusions

Dega pelvic osteotomy using iliac crest allograft was effective in correcting acetabular dysplasia, without graft-related complications in patients with CP. Furthermore, the correction of acetabular dysplasia remained stable during the follow-up period.

Fate of stable hips after prophylactic femoral varization osteotomy in patients with cerebral palsy

Background

Concurrent prophylactic femoral varization osteotomy (FVO) for stable hips has been performed in patients with cerebral palsy (CP) undergoing hip reconstructive surgery for the contralateral displaced hip. However, there is currently a lack of studies investigating the outcome after the prophylactic FVO in stable hip. This study investigated the outcomes after FVO in stable hips with CP and influencing factors. In addition, this study compared the outcomes with those after hip reconstructive surgery in the contralateral displaced hip.

Methods

This study included 119 CP patients with 224 hips (80 stable, 144 displaced) undergoing hip reconstructive surgery including FVO. Migration percentage (MP), neck-shaft angle (NSA), and head-shaft angle (HSA) were measured through preoperative and follow-up hip radiographs. All hips were divided into the stable (MP ≤ 33%) and displaced hip groups (MP > 33%) according to the preoperative radiographs, and the annual changes in the radiographic indices after FVO were analyzed.

Results

In stable hip group, MP did not significantly increase over time (p = 0.057) after prophylactic FVO. In displaced hip group, MP significantly increased over time (1.6%/year, p < 0.001). MP was significantly decreased in cases of concomitant Dega pelvic osteotomy in both stable (14.5%, p < 0.001) and displaced hips (18.9%, p < 0.001).

Conclusions

Prophylactic FVO in the stable hip in patients with CP showed good surgical outcomes, without a risk of hip displacement throughout the follow-up duration, while hip reconstructive surgery in the displaced hip was associated with a risk of increased hip displacement.

Hip Surveillance in Children with Cerebral Palsy

The hip is the second most common involved joint in cerebral palsy. Hip displacement occurs in more than 33% of children with cerebral palsy, with a higher prevalence in nonambulatory children. Hip displacement in this population is typically progressive. Hip dislocation can result in pain and difficulty with sitting and perineal care. Since early stage of hip displacement can be silent, and hip surveillance programs are recommended. Most programs use the degree of hip dysplasia and Growth Motor Function Classification System level for screening recommendations. Treatment depends on the degree of dysplasia, functional status of the patient, and patient's age.

Combined pelvic and femoral reconstruction in children with cerebral palsy

Objective

The primary aim of this study was to determine the effect of age, femoral head migration, and ambulatory status on radiographic outcomes after combined pelvic and femoral reconstruction in children with cerebral palsy. The secondary aim was to evaluate the fate of the opposite hip after unilateral reconstruction.

Methods

A retrospective cohort study design of consecutive patients from 1995–2009 was used. The records were screened for patients who underwent varus derotational osteotomy and modified Dega osteotomy.

Results

Eighty-five hips in 71 patients were included. The mean age was 8.4 ± 3.2 years and the mean follow-up was 6.6 ± 3.1 years. The final measures were a mean migration index of 20% ± 15.58%, centre edge angle of 28.45° ± 15.98°, and Sharp’s angle of 40.75° ± 8.5°. Those values were not correlated with age and the initial migration index. Nonambulatory status did not negatively affect hip stability. Final measurements of the contralateral hips were similar to the reconstructed hips, and the cumulative incidence for later reconstruction was 5.67%.

Conclusions

Regardless of age, preoperative displacement, and ambulation, the combined procedure provides durable radiographic improvement. In unilateral cases, there is a low risk of later deterioration of the opposite side.

Functional status and amount of hip displacement independently affect acetabular dysplasia in cerebral palsy

AIM

Acetabular dysplasia is the one of main causes of hip displacement in patients with cerebral palsy (CP). Although several studies have shown a relationship between hip displacement and acetabular dysplasia, relatively few have evaluated the association between quantitative acetabular dysplasia and related factors, such as Gross Motor Function Classification System (GMFCS) level.

METHOD

We performed a morphometric analysis of the acetabulum in patients with CP using multiplanar reformation of computed tomography data. The three directional acetabular indices (anterosuperior, superolateral, and posterosuperior) were used to evaluate acetabular dysplasia. Consequently, linear mixed-effects models were used to adjust for related factors such as age, sex, GMFCS level, and migration percentage.

RESULTS

A total of 176 patients (mean age 9y 5mo, range 2y 4mo-19y 6mo; 104 males, 72 females) with CP and 55 typically developing individuals (mean age 13y 6mo, range 2y 5mo-19y 10mo; 37 males, 18 females) in a comparison group were enrolled in this study. Statistical modelling showed that all three directional acetabular indices independently increased with GMFCS level (p<0.001) and migration percentage (p<0.001).

INTERPRETATION

Acetabular dysplasia was independently affected by both the amount of hip displacement and the GMFCS level. Thus, physicians should consider not only the migration percentage but also three-dimensional evaluation in patients at high GMFCS levels.

A balanced approach for stable hips in children with cerebral palsy: a combination of moderate VDRO and pelvic osteotomy

BACKGROUND

Hip reconstructive surgery in cerebral palsy (CP) patients necessitates either femoral varus derotational osteotomy (VDRO) or pelvic osteotomy, or both. The purpose of this study is to review the results of a moderate varisation [planned neck shaft angle (NSA) of 130°] in combination with pelvic osteotomy for a consecutive series of patients.

METHODS

Patients with CP who had been treated at our institution for hip dysplasia, subluxation or dislocation with VDRO in combination with pelvic osteotomy between 2005 and 2010 were reviewed.

RESULTS

Forty patients with a mean follow-up of 5.4 years were included. The mean age at the time of operation was 8.9 years. The majority were non-ambulant children [GMFCS I-III: n = 11 (27.5 %); GMFCS IV-V: n = 29 (72.5 %)]. In total, 57 hips were treated with both femoral and pelvic osteotomy. The mean pre-operative NSA angle of 152.3° was reduced to 132.6° post-operatively. Additional adductor tenotomy was performed in nine hips (16 %) at initial operation. Reimers' migration percentage (MP) was improved from 63.6 % pre-operatively to 2.7 % post-operatively and showed a mean of 9.7 % at the final review. The results were good in 96.5 % (n = 55) with centred, stable hips (MP <33 %), fair in one with a subluxated hip (MP 42 %) and poor in one requiring revision pelvic osteotomy for ventral instability.

CONCLUSIONS

This approach maintains good hip abduction and reduces soft-tissue surgery. Moderate varisation in VDRO in combination with pelvic osteotomy leads to good mid-term results with stable, pain-free hips, even in patients with severe spastic quadriplegia.

Acetabular and femoral remodeling after varus derotational osteotomy in cerebral palsy: the effect of age and Gross Motor Function Classification Level

This study investigated the degree of acetabular and femoral remodeling after isolated varus derotation osteotomy (VDRO) in children with cerebral palsy. This retrospective review investigated 56 children (103 hips) who underwent VDROs for spastic hip displacement between 1994 and 2007. The average age of the patients at surgery was 7.7 years and the follow-up duration was 7.8 years (range 5-11 years). The acetabular index showed a significant linear decrease (P<0.001), with children of less than 6 years showing the greatest correction (P<0.001). VDRO without pelvic osteotomy does result in a mild improvement in acetabular dysplasia over time, with greater rates of correction found in children of less than 6 years old.

LEVEL OF EVIDENCE

Therapeutic Study - Level IV.