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

Prevalence and Treatment of Surgical Complications Following Proximal Femoral Osteotomies in Children with Cerebral Palsy: An Analysis of 1085 Hips

Purpose

Proximal femoral osteotomy (PFO) is a reconstructive surgical option used to improve hip containment or correct internal hip rotation gait in children with cerebral palsy (CP). A few reports describe the risk of surgical complications after PFO. The purpose of this study was to determine the risk factors associated with adverse postoperative surgical outcomes in pediatric patients with CP following PFO and to report the treatment of complications.

Methods

Following institutional review board approval, 1085 (1003 primary and 82 secondary) PFO procedures were retrospectively reviewed in 563 children with CP with at least 1 year of follow-up after final surgery over an 18-year follow-up period. Demographic characteristics, motor type, gross motor function classification system (GMFCS) level, medical comorbidities, feeding tube status, seizure history, intervention type, and prevalence of PFO-related surgical complications and associated treatments were evaluated. Multivariate regression analysis was performed to determine risk factors for all surgical complications.

Results

During a 5.8-year (± 3.8 years) follow-up, at least 1 surgical complication was identified in 143 (13.1%) hips in 121 (21.5%) patients after PFO in children with CP. Of these complications, the most common was heterotopic ossification (65 [6%] of hips); most of which were asymptomatic and required no treatment. Other complications included 25 (2%) nonunions, 21 (2%) deep or superficial infections, 13 (1%) delayed unions, 12 (1%) peri-implant fractures, and 7 early implant failures (0.64). The rate of revision surgery due to these complications was 13.1% (6.8% of hips), of which 41% (30 revision surgeries) were for the treatment of nonunion. Regarding the development of delayed union or nonunion, dystonia, GMFCS level IV/V, and seizure history were identified as risk factors by multivariate analysis.

Conclusions

The prevalence of surgical complications after PFO was 13.1% with 6.8% of hips requiring revision surgery. Dystonia, seizure history, and nonambulatory status were the strongest predictors for the need for revision surgery after PFO. These data can be used to help counsel patients and families regarding the risks associated with PFO for children with CP.Level of proof: IV; retrospective study.

Does Acetabulum Remodel Following Varus Derotation Osteotomy for Perthes' Disease?

Objective  We investigated the effect of disease stage, patient's age and final contour of femoral head on acetabulum contour following varus derotation osteotomy of proximal femur (VDRO) in unilateral Perthes's disease. Methods  The study is a retrospective analysis of case records of 23 children aged ≥6 years with unilateral Perthes' disease who underwent primary VDRO procedure for containment. Acetabular index (AI) and center edge angle (CEA) were calculated bilaterally in preoperative and follow-up radiographs and compared statistically. Results  There were 15 boys and 8 girls. Six hips were in Ib, 8 in IIa and 9 in IIb modified Waldenström stage while undergoing VDRO. The mean age at surgical intervention was 8.7 years. The mean follow-up duration was 3.5 years. All femoral heads were healed at final follow-up and the final Stulberg grades were I = 3, II = 8, III = 7, IV = 5. A significant acetabular dysplasia on the affected side was present preoperatively. At follow-up, the patients operated had significantly raised AI and reduced CEA. There was no significant acetabular remodeling of the affected hips at follow-up even in children operated at younger age (< 8 years) or early stages (stage Ib or IIa). The acetabulum remodeling did not correspond to the final Stulberg grade as well. Conclusion  Acetabulum was found involved in early stages of Perthes' disease. Varus derotation femoral osteotomy for the diseased hip showed no significant improvement in acetabular dysplasia even when operated in early disease stages or younger age group. Residual acetabular changes were also noted even with favorable Stulberg grades.

Postoperative Immobilization After Hip Reconstruction in Cerebral Palsy: No Difference Between Hip Spica and Abduction Pillow

Purpose

This study aims to compare radiographic outcomes and complication rates of immobilization with an abduction pillow to spica casting for postoperative care after a hip reconstruction with varus derotational proximal femur osteotomy (VDRO) with or without pelvic osteotomy for children with cerebral palsy (CP).

Methods

233 children (1–18 years old) diagnosed with CP that underwent VDRO with or without pelvic osteotomy were identified, of which 188 patients were immobilized with a spica cast and 45 were immobilized with an abduction pillow, based on surgeon preference. 123 (65%) in the Spica group and 21 (47%) in the pillow group had pelvic osteotomies. Demographic data and complication rates were collected. Radiographic parameters, including anatomic medial proximal femoral angle (aMPFA), acetabular index (AI) and migration percentage (MP), were measured for each patient at the completion of surgery, six weeks post-operatively, and one year post-operatively.

Results

There was not a statistically significant difference in BMI (p = 0.285), gender distribution (p = 0.984), or median follow-up time (p = 0.314) between groups. Rates of complications were consistent among groups with no differences in instances of delayed unions (p = 0.10), subluxations (p = 0.55), infection (p = 0.71), or non-unions (p = 0.10). There was no statistically significant difference in number of patients with an ideal aMPFA, AI, or MP (p = 0.44, p = 0.19, p = 1.00) at one year post-operatively.

Conclusions

Immobilization with an abduction pillow is a safe and effective alternative to hip spica casting following hip reconstruction.

Long-term outcomes of hip reconstruction surgery in children with GMFCS III diplegic cerebral palsy

INTRODUCTION

The results of hip reconstruction surgery are known for non-walking (GMFCS IV and V) and walking (GMFCS I and II) patients. Few studies deal with GMFCS III patients in isolation. Their intermediate functional status can be deteriorated by asymmetrical contractures, hip dislocation, multi-level deformities of the lower limbs, leading to motor function degradation, and possibly losing their ability to walk. The aim of our study was to establish whether surgical results were maintained over time and whether the functional status changed.

MATERIAL AND METHODS

Fifteen patients with GMFCS III spastic diplegia, treated for hip subluxation, were reviewed. The mean age at the time of surgery was 10 years old. The mean follow-up after surgery was 11 years. Reconstructive surgery was performed on 21 hips including pelvic osteotomy in all cases, with associated femoral osteotomy in 19 cases. Clinical (pain, joint mobility, walking aids, walking distance, GMFCS level) and radiological data (Melbourne Cerebral Palsy Hip Classification, standard coxometry) were recorded preoperatively and at the last follow-up.

RESULTS

Preoperatively, 6 patients were losing their ability to walk due to pain and flexion-adduction contracture. At the last follow-up, no patients had pain and joint mobility was improved in all cases. For one patient, recovery to their previous functional state required a period of two years. In the long term, 14 patients were GMFCS III and only one patient was GMFCS IV due to reasons unrelated to hip surgery. The radiological parameters improved significantly. The Melbourne score was IV preoperatively for all patients. At the last follow-up, 10 hips were grade I, 6 hips were grade II and 5 hips were grade III.

DISCUSSION

Correction of architectural disorders of the subluxed hip by pelvic osteotomy, in most cases associated with femoral osteotomy, improves functional and radiological status for GMFCS III patients. This improvement is maintained in the long-term. Complementary surgeries correcting the other deformities of the lower limbs were necessary in more than half of the patients.

LEVEL OF EVIDENCE

IV.

Derotational Subtrochanteric Osteotomy and External Fixation for the Treatment of Neurogenic Hip Dislocation in Children with Cerebral Palsy: Could This Be a Viable Method of Treatment?

Purpose The treatment of painful and chronic dislocated hip in children with severe cerebral palsy (CP) is particularly demanding and controversial. Numerous surgical techniques have been described, and their outcomes vary a lot. The purpose of the present study is to evaluate a new method, which combines varus derotational subtrochanteric osteotomy (VDSO) and external osteosynthesis: (VDSOEO). Methods Six non-ambulatory children with spastic quadriplegia and chronic dislocated painful hips were treated. The technique involved a small incision on the subtrochanteric site of the osteotomy, followed by retention with a single-sided external osteosynthesis with rotational correction capability [swiveling clamp (SC)] for the reduction of the femur head in the acetabulum, and finally by the osteotomy. Hardware was removed without a second intervention four-six months postoperatively and after the osteotomy was healed. Evaluation of the method was based on clinical, functional, and radiological criteria. Results  Four patients achieved improved radiological scores. Two patients demonstrated resubluxation during the period of the osteotomy's healing process. However, no patients experienced pain, and all were able to sit post-surgery, while caregivers reported improved capacity for nursing care. Conclusions It is our strong belief that this approach can improve the quality of life in children with severe CP and painful and chronic dislocated hips. It is a viable and definitely less invasive procedure than classic pelvic or femur osteotomies.

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.

Migration percentage and odds of recurrence/subsequent surgery after treatment for hip subluxation in pediatric cerebral palsy: a meta-analysis and systematic review

PURPOSE

This meta-analysis aims to systematically assess and quantitatively pool the best clinical evidence for migration percentage (MP) and odds ratio (OR) for recurrence/reoperation following treatment for hip subluxation in children with cerebral palsy (CP), including Botulinum Toxin A (BNT-A), soft-tissue lengthening and osteotomies.

METHODS

Pubmed, EMBASE and Cochrane were systematically searched from between 1 January 1953 and 11 January 2017 inclusive for studies reporting resubluxation/reoperation rates, and/or MP following treatment for hip subluxation in children with CP. The primary outcome was odds of resubluxation/reoperation. The secondary outcome was change in MP. Studies were graded for quality using the Newcastle Ottawa Scale. This meta-analysis was performed and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

A total of 14 studies were included in analysis of odds of resubluxation/reoperation and 24 studies were included in analysis of MP. The OR for resubluxation/reoperation was lower for combined osteotomies compared with femoral (OR = 0.49; 95% confidence interval (CI) 0.25 to 0.98) and for femoral osteotomy compared to soft-tissue procedures (OR = 0.20; 95% CI 0.07 to 0.61). There was no difference in odds of recurrence/reoperation between pelvic and femoral osteotomies (OR = 2.27; 95% CI 0.37 to 13.88). Combined osteotomies provided the greatest improvement in MP, while BoNT-A showed no improvement in MP.

CONCLUSION

Resubluxation/reoperation rates are high; management with osteotomies is preferred to soft-tissue procedures alone in preventing resubluxation/reoperation. This meta-analysis is limited by the observational nature and small sample sizes of many of the included studies, with their inherent risk of bias and lack of homogeneity of patient characteristics at baseline. It is possible that with larger and higher quality studies, the results and conclusions of this analysis may be altered.

Does Orientation of the Femoral Head Affect Acetabular Development? An Experimental Study in Lamb

BACKGROUND

Derotational osteotomy of the proximal femur has proved to be effective in the treatment of residual acetabular dysplasia. However, the reason why this osteotomy is effective remains debatable. The purpose of this study is to investigate if an alteration of femoral head orientation affects acetabular growth.

METHODS

A proximal femoral osteotomy was performed in 21 lambs aged 3 months: 5 varus osteotomies (110 degrees), 4 valgus osteotomies (150 degrees), and 12 derotation osteotomies. Results were compared with a control group (5 animals). Osteotomy was fixed with a screw-plate device. Version was controlled intraoperatively with K-wires. Animals were killed 3 months after surgical procedure. A morphometric study of both proximal femur and acetabulum was performed, including deepness, volume and diameters of the acetabulum, neck-shaft angle and femoral version.

RESULTS

The average neck-shaft angle for the normal, anteversion, and retroversion groups was 129 degrees, whereas it was 110 degrees for the varus group and 149 degrees for the valgus group. The average femoral version for the normal, valgus, and varus groups was 21 degrees of anteversion, whereas it was 38 degrees of anteversion for the so-called anteversion group and 17 degrees of retroversion for the retroversion group. Nor the neck-shaft angle, nor the femoral version correlated with the acetabular anteroposterior diameter (P=0.698, 0.6, respectively), the acetabular inferosuperior diameter (P=0.083, 0.451, respectively) or the acetabular deepness (P=0.14, 0.371, respectively). The neck-shaft angle correlated significantly with acetabular volume (P=0.023), so that the lower the neck-shaft angle, the higher the acetabular volume (r=-0.453). The femoral version did not correlated with acetabular volume (P=0.381).

CONCLUSIONS

Decreasing the neck-shaft angle provokes an increase in acetabular volume, whereas changes in femoral version do not affect the acetabular growth. Extra-articular osteotomies that alter femoral orientation affect intra-articular gross morphology.

LEVEL OF EVIDENCE

Level II-therapeutic study.

The spastic hip in children and adolescents

The hip is the joint most exposed to orthopaedic complications in cerebral palsy (CP), which is the main cause of spasticity in paediatric patients. The initial immaturity of the hip allows the forces applied by the spastic and retracted muscles to displace the femoral head, eventually causing it to dislocate. The risk of hip dislocation increases with the severity and extent of CP, exceeding 70% in the most severe cases. Hip dislocation causes pain in up to 30% of cases, carries a risk of orthopaedic and cutaneous complications and hinders patient installation and nursing care. These adverse outcomes warrant routine screening, which has been proven effective in lessening the frequency and severity of hip displacement. Preventive techniques including physical therapy, orthoses and treatments to alleviate spasticity are strongly recommended in every case. The beneficial effects of treating spasticity, if needed via neurosurgical procedures, have been convincingly established. Orthopaedic surgery is required when prevention fails. Soft-tissue release is designed to correct the asymmetry in the forces applied by the muscles. Femoral osteotomy creates the possibility for spontaneous correction of secondary acetabular dysplasia. Progress has been made in standardising the use of multilevel surgery involving the soft tissues, femur and pelvis, which is often effective in correcting the morphological abnormalities and stabilising the joint. When hip pain or alterations are severe, hip resection or total hip arthroplasty are highly effective in alleviating the pain and improving patient comfort. The spastic hip is a complex condition in which currently available screening protocols and treatment strategies have been proven effective in benefitting patient outcomes.

Preoperative hip rotation moments do not predict long-term development after femoral derotation osteotomy in children with cerebral palsy

BACKGROUND

Femoral derotation osteotomy (FDO) is the standard treatment for internal rotation gait (IRG) in children with cerebral palsy (CP) although high rates of recurrence have been reported recently. Various factors associated with recurrence could be identified, but no predictor named.

RESEARCH QUESTIONS

Does FDO lead to a change of internal transversal hip moments? Are preoperative internal transversal hip moments a predictor for recurrence of IRG?

METHODS

41 children with spastic bilateral CP and 72 limbs that received a FDO (10.4 ± 2.7 years at surgery) were included retrospectively. Kinematic data were analyzed pre- (2 ± 3 months), postoperatively (12 ± 3 months) and at long-term follow-up (at least five years postoperatively; 84 ± 13 months), internal transversal hip moments were analyzed pre- and postoperatively.

RESULTS

The maximum peaks of the internal hip rotation moment during loading response decreased significantly (p = 0.003). The minimum during the second half of the stance phase increased significantly (p = 0.004) and the initially internal externally rotating moment changed to an internal internally rotating moment. No correlation between changes in hip rotation from postoperatively to the long-term follow-up and the preoperative internal hip rotation moment could be identified.

SIGNIFICANCE

FDO leads to changes in internal hip rotation moments. Preoperative internal hip rotation moments can't be used as predicting factor for recurrence of IRG. The data suggest, that recurrence of IRG depends less on patient specific motion patterns, but more on the time point of surgery and the therapy of all concomitant deformities during SEMLS.

Long-term development of overcorrection after femoral derotation osteotomy in children with cerebral palsy

BACKGROUND

Recent studies showed rates of recurrence of internal rotation gait (IRG) after femoral derotation osteotomy (FDO) up to 40%. Some surgeons even advice overcorrection during FDO to avoid a later recurrence.

RESEARCH QUESTION

Evaluation of the long-term development of limbs with initial overcorrection after FDO.

METHODS

29 limbs of 20 children (9.9 ± 3.2 years at surgery) with IRG, cerebral palsy (CP) and more than 5° external hip rotation postoperatively were included retrospectively. A gait analysis and clinical examination were performed preoperatively (less than one year, E0), postoperatively (9-23 months, E1) and at the long-term follow-up (at least five years postoperatively, E2). Differences between those children that remained overcorrected at E2 and those with a hip rotation within normal range at E2 were evaluated.

RESULTS

At E2 41% of these limbs remained overcorrected, 52% showed a hip rotation within normal range and 7% showed recurrence of IRG. A comparison of those limbs that remained overcorrected and those ending within normal range revealed neither a difference in age at surgery nor in static and dynamic torsional parameters at E0 and E1 except for pelvic rotation. A significantly larger pelvic internal rotation at E1 for those with remaining overcorrection could be identified.

SIGNIFICANCE

A general overcorrection during FDO in children with CP to avoid recurrence of IRG cannot be recommended, as 41% remain overcorrected. Preoperative predictors for long-term development couldn't be identified. If pelvic mal-rotation is corrected, hip rotation may change into normal range over the time in combination with the development of a flexed knee gait.