Factors Influencing Outcomes of the Dysplastic Hip in Nonambulatory Children With Cerebral Palsy

Conventional versus locked plates for hip dislocation in cerebral palsy: a matched cohort analysis

PURPOSE

Bone quality of non-ambulatory patients with cerebral palsy (CP) is a matter of concern for proximal femoral varus derotational osteotomies (VDRO). Locking plates (LCP) have been designed to compensate this biological downfall. Little data exist comparing the LCP with the conventional femoral blade plate.

METHODS

We retrospectively studied 32 patients submitted to VDRO (40 hips), operated with blade plates or LCP. Groups were matched, and the minimal follow-up was 36 months. Clinical (age at surgery, sex, GMFCS class, CP patterns) and radiological characteristics (neck shaft angle [NSA], acetabular index [AI], Reimers migration index [MP] and time until bone healing), as well as postoperative complications and the cost of treatment, were evaluated.

RESULTS

Preoperative clinical characteristics and radiographic measurements were comparable, except for a higher AI in the BP group (p < 0.01). Mean follow-up was longer in the LCP group (57.35 vs 34.6 months). Mean NSA, AI and MP had comparable correction with surgery (p < 0.01). At final follow-up, dislocation recurrence speed was higher in BP group although not statistically significant (0.56% vs 0.35%/month; p = 0.29). The complication rate was similar in both groups (p > 0.05). Finally, the cost of the treatment was 62% higher in the LCP group (p = 0.01).

CONCLUSION

Our cohorts showed LCP or BP equivalence clinically and radiographically in mid-term follow-up, with the former increasing the cost of treatment by a mean of 62%. This may raise a question on the real necessity of locked implants for these operations.

LEVEL OF EVIDENCE

Level III-Retrospective comparative study.

Hip reconstruction in children with cerebral palsy: does magnitude of surgery influence complications and outcomes?

Children with cerebral palsy (CP) and neuromuscular hip dysplasia (NMHD) frequently require hip reconstruction including femoral and pelvic osteotomies. Outcomes and complications in CP patients with NMHD who underwent varying degrees of hip reconstruction surgeries were examined. Ninety-nine patients with a diagnosis of CP who underwent surgical management of NMHD over a 15-year period (2005-2020) were reviewed. Three patient cohorts with varying degrees of surgery were analyzed including: (1) unilateral femoral osteotomy with pelvic osteotomy; (2) bilateral femoral osteotomy with unilateral pelvic osteotomy; and (3) simultaneous bilateral femoral osteotomy and bilateral pelvic osteotomy. Data points included operative (OR) time, length of stay (LOS), estimated blood loss (EBL), and transfusion requirement. Complications during the perioperative and postoperative periods were identified and graded by severity. Increased EBL, need for transfusion, OR time, and LOS were observed more frequently in patients undergoing bilateral reconstruction. Complication rates were high for all three cohorts, with 87% of cases in the bilateral pelvic osteotomy cohort experiencing ≥1 complication. However, 90% of these were considered grade I or II and required no or minimal intervention. The average postoperative migration index at final follow-up for treated hips was significantly less in bilateral pelvic osteotomy cases. Patients with CP and bilateral NMHD can be safely managed with bilateral simultaneous comprehensive reconstruction. The data presented in this study can help both surgeons and families anticipate a more accurate postoperative course. Level of evidence: III.

Hip Displacement After Triradiate Cartilage Closure in Nonambulatory Cerebral Palsy: Who Needs Continued Radiographic Surveillance?

BACKGROUND

Recommendations with regard to the need for continued hip surveillance after skeletal maturity are based on expert opinion rather than evidence. This study aimed to determine the prevalence of and risk factors associated with progressive hip displacement in cerebral palsy (CP) after triradiate cartilage (TRC) closure.

METHODS

Patients who had spastic nonambulatory CP (Gross Motor Function Classification System IV to V) and hypertonic (spastic or mixed-type) motor type and follow-up of at least 2 years after TRC closure were included. The primary outcome variable was the hip migration percentage (MP). The secondary outcome variables included patient age at the time of TRC closure, prior preventative or reconstructive surgery, a prior intrathecal baclofen pump, history of scoliosis, history of epilepsy, a prior gastrostomy tube, a previous tracheostomy, and gender. An unsuccessful hip outcome was defined as a hip with an MP of ≥40% and/or requiring a reconstructive surgical procedure after TRC closure.

RESULTS

In this study, 163 patients met the inclusion criteria, with a mean follow-up of 4.8 years (95% confidence interval [CI], 4.4 to 5.1 years) after TRC closure at a mean patient age of 14.0 years (95% CI, 13.7 to 14.3 years). Of these hips, 22.1% (36 of 163) had an unsuccessful hip outcome. In multivariate analysis, the first MP at TRC closure (hazard ratio [HR] per degree, 1.04; p < 0.001) and pelvic obliquity (HR per degree, 1.06; p = 0.003) were independent risk factors for an unsuccessful hip outcome, but gender was not found to be significant (HR for male gender, 1.7 [95% CI, 0.8 to 3.58; p = 0.16]; female gender was the reference). However, the mean survival time for progression to an unsuccessful hip outcome was longer for female patients at 9.2 years [95% CI, 8.1 to 10.2 years]) compared with 6.2 years (95% CI, 5.6 to 6.9 years) for male patients (p = 0.02). There was also a significant improvement in survivorship for prior reconstructive surgical procedures (p = 0.002). The survivorship in patients who underwent reconstructive surgery performed at a patient age of ≥6 years was significantly higher compared with those who underwent surgery performed at <6 years of age (p < 0.05). A first MP at TRC closure of ≥35% was associated with an unsuccessful hip outcome, as determined by receiver operating characteristic (ROC) curve analysis (p < 0.001; area under the ROC curve of 0.891, sensitivity of 81%, and specificity of 94%).

CONCLUSIONS

The risk factors for the progression of hip displacement after TRC closure in patients with CP included a higher MP and increased pelvic obliquity; there was decreased survivorship for male patients and patients with no prior reconstructive surgery. Patients with these risk factors and/or an MP of ≥35% at TRC closure should have continued radiographic surveillance to detect late hip displacement.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Cerebral Palsy: Current Concepts and Practices in Musculoskeletal Care

Cerebral palsy is a neurologic disorder characterized by a spectrum of motor and cognitive deficits resulting from insults to the developing brain. The etiologies are numerous and likely multifactorial; an increasing portion of cases may be attributable to genetic causes, although the exact mechanisms responsible remain poorly understood. Major risk factors include intrauterine stroke and prematurity and neonatal infection, trauma, and hypoxia, which may occur in the prenatal, perinatal, or postnatal period. The Gross Motor Function Classification System (GMFCS) is a widely used tool to establish a child's level of function and to guide treatment; however, additional metrics are necessary to formulate long-term prognoses. Goals of care are to maximize function and independence, which directly correlate with overall quality of life, and family participation is key to establishing goals early in treatment. Nonpharmaceutical treatments include physical, occupational, and speech therapy, as well as bracing, equipment, and technology. There is a breadth of medical interventions for managing hypertonia, including medications, botulinum toxin injections, intrathecal baclofen pumps, and selective dorsal rhizotomy. Orthopedic interventions are indicated for symptomatic or progressive musculoskeletal sequelae. Treatments for dysplastic hips and/or hip instability range from soft tissue releases to bony procedures. Neuromuscular scoliosis is managed with posterior spinal fusion because bracing is ineffective against these rapidly progressive curves. The degree of care varies considerably depending on the child's baseline GMFCS level and functional capabilities, and early screening, diagnosis, and appropriate referrals are paramount to initiating early care and maximizing the child's quality of life.

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.