Hip Displacement Surveillance in Cerebral Palsy

Can hip dislocation in cerebral palsy be prevented?

The risk of hip dislocation in children with Cerebral Palsy ranges from 15-20% to 75% in the most severely affected patients. This dislocation is not present at birth but develops progressively over the years. Go to the factsheet: general information on dislocation .

Patient care providers are responsible for implementing programs to identify any deterioration early and direct patients to facilities capable of correcting such conditions before they develop into serious and difficult-to-resolve conditions.

Currently, Italy lacks codified surveillance programs for hip dislocation in cerebral palsy aimed at early identification of patients at risk. Clinical and radiographic examinations are often arranged based on the preferences of individual physicians, physiotherapists, or individual centers, and are often discontinuous.

However, the consequences of dislocation can be significant. If the patient is able to walk, it can result in a loss of stability and gait; in more severely affected patients, however, it can cause difficulties with daily hygiene, maintaining a sitting position, the onset of pelvic obliquity, scoliosis, and, above all, pain when moving the limb. Pain secondary to dislocation is a controversial topic, and many professionals do not believe that hip dislocation causes pain in patients with Cerebral Palsy . The literature also presents case studies with differing results.

A recently published study (Wawrzuta et al, Dev Med Child Neurol 2016) reports pain in 72% of patients (average age: 18 years) with subluxated or dislocated hips and describes a factor that should hold professionals accountable: pain and hip morphology were not related to the patient’s severity, but rather to whether or not the patient had had the opportunity to be enrolled in a hip monitoring program. Part of the controversy also stems from the difficulty communicating pain in more severely ill children ( in many cases, an indirect manifestation is insomnia or malnutrition ) or from the fact that many professionals who care for young children with Cerebral Palsy do not follow the same patients into adolescence/adulthood, when growth and local pathological changes lead to painful symptoms.

We also underline that while it is true that there are cases in which hip dislocation is not painful, there are cases in which the pain is worsening and causes a serious alteration of the patient’s state of health: and in these cases, the therapeutic possibilities are limited, as conservative treatments (for example, infiltrative treatments) have limited effects and so-called “salvage” surgical treatments (resection of the proximal femur, Schanz osteotomies of femoral valgus, etc.) have uncertain and overall poor results.

Experiences abroad: surveillance protocols in cerebral palsy.

Experiences conducted abroad have highlighted the possibility of effective approaches to reducing cases of advanced dislocation in patients with Cerebral Palsy . Health surveillance programs were launched in Sweden in 1994 and in Australia in 1997, with the aim of identifying patients at risk and preventing hip dislocation in children with Cerebral Palsy . The results of these programs (with 10- and 20-year follow-ups) were so positive that the surveillance program was extended to other Northern European countries (Norway, Denmark, Iceland, Scotland) in 2005.
The Swedish and Australian protocols are slightly different but are based on similar principles.
More recently, in 2017, a surveillance protocol was also introduced in the USA.

How to monitor and diagnose hip subluxation early in a patient with Cerebral Palsy?

Clinical examination can be helpful, but it is not sufficient : in many cases, the results of the exam can be negative even in the presence of a hip alteration. Therefore, the only way to detect early worsening of the condition is to perform periodic radiographic examinations . The examination now considered the standard for these purposes is a pelvic X-ray performed with the patient supine, with the limbs aligned and the patellae at their zenith.

Unfortunately, X-rays are often requested incorrectly (for example, standing), leading to poor validity and reproducibility of the results.

On this x-ray, the Migration Index will be evaluated , that is, the percentage of the femoral head that remains uncovered with respect to the edge of the acetabulum.

The first X-ray should be performed early (around 24 months of age) to identify cases in which the dislocation occurs prematurely.
The frequency of repeat X-rays varies, up to once or twice a year, and should be proportional to the actual risk of dislocation. This risk is related to the subtype of Cerebral Palsy (higher in spastic than in ataxic forms; higher in tetraparesis than in diplegia, and higher in diplegia than in hemiparesis), but using the subtype of cerebral palsy as an indicator of dislocation risk has limitations: for example, it is not uncommon for the same patient to be classified differently (tetraparesis, diplegia, double hemiparesis) by different operators.

For this reason, the Gross Motor Function Classification System (GMFCS) is used as the most reliable predictor . While patients with GMFCS V (non-ambulatory, wheelchair-bound) have a high risk of dislocation, the risk progressively decreases to a minimal risk for GMFCS I (ambulatory without limitations). This implies the need for frequent examinations for the former and progressively less frequent for the latter.

Without going into specifics, in the Swedish protocol , children with GMFCS levels V (transported in a manual wheelchair), IV (independent mobility with limitations; possible mobility with a powered mobility device), and III (walking with a manual mobility device) undergo an x-ray annually until age 8 (after which the intervals vary depending on the clinical examination and previous x-ray results). Level II (walking with limitations) only undergoes x-rays at ages 2 and 6. Level I (walking without limitations) does not undergo x-rays until hip mobility is normal and painless.
The Australian program requires more frequent x-rays (twice a year for GMFCS V), but unlike the Swedish program, it does not require an annual clinical evaluation by a physiotherapist.
The frequency of these exams may be increased in the event of : a rapid increase in the migration index, a migration index greater than 30%, the onset of scoliosis or pelvic obliquity, or the onset of movement limitations.
Based on the results of these tests, operators will implement corrective measures.

A new scheme proposed for Italy

The various protocols used abroad differ slightly based on the different healthcare system structures. Following an analysis of the various programs used in other countries, we have developed a radiological surveillance framework that can be applied to the Italian situation.

Bibliography

• Shrader MW, Wimberly L, Thompson R. Hip Surveillance in Children With Cerebral Palsy. J Am Acad Orthop Surg. 2019 Oct 15;27(20):760-768
• Wynter M, Gibson N, Willoughby KL, Love S, Kentish M, Thomason P, Graham HK; National Hip Surveillance Working Group. Australian hip surveillance guidelines for children with cerebral palsy: 5-year review. Dev Med Child Neurol. 2015 Sep;57(9):808-20.
• Hägglund G, Alriksson-Schmidt A, Lauge-Pedersen H, Rodby-Bousquet E, Wagner P, Westbom L. Prevention of dislocation of the hip in children with cerebral palsy: 20-year results of a population-based prevention programme. Bone Joint J. 2014 Nov;96-B(11):1546-52
• Robb JE, Hägglund G. Hip surveillance and management of the displaced hip in cerebral palsy. J Child Orthop. 2013 Nov;7(5):407-13.
  Boston Children’s Cerebral Palsy Hip Surveillance Screening Guide
  Holland Bloorview CP Hip Surveillance Clinical Care Pathway: Anne Kawamura, Chun Kim, Angie Ip, Peggy Curtis, Shauna Kingsnorth, Darcy Fehlings
• Huser A, Mo M, Hosseinzadeh P. Hip Surveillance in Children with Cerebral Palsy. Orthop Clin North Am. 2018 Apr;49(2):181-190.
  Shore BJ, Shrader MW, Narayanan U, Miller F, Graham HK, Mulpuri K. Hip Surveillance for Children With Cerebral Palsy: A Survey of the POSNA Membership. J Pediatr Orthop. 2017 Oct/Nov;37(7):e409-e414.
• Miller SD, Shore BJ, Mulpuri K. Hip Surveillance is Important to Children with Cerebral Palsy: Stop Waiting, Start Now. J Am Acad Orthop Surg Glob Res Rev. 2019 Apr 10;3(4):e021.
• Miller S, Bone J, Mulpuri K. Suspension of Hip Surveillance for Children with Cerebral Palsy During the COVID-19 Outbreak: The Benefit of Hip Surveillance Does Not Outweigh the Risk of Infection. Indian J Orthop. 2020 Aug 28:1-3.
• Wawrzuta J, Willoughby KL, Molesworth C, Ang SG, Shore BJ, Thomason P, Graham HK. Hip health at skeletal maturity: a population-based study of young adults with cerebral palsy. Dev Med Child Neurol. 2016 Jun 17.
• Hägglund G, Andersson S, Düppe H, Lauge-Pedersen H, Nordmark E, Westbom L. Prevention of dislocation of the hip in children with cerebral palsy. The first ten years of a population-based prevention programme. J Bone Joint Surg Br. 2005 Jan;87(1):95-101.
• Dobson F, Boyd RN, Parrott J, Nattrass GR, Graham HK. Hip surveillance in children with cerebral palsy. Impact on the surgical management of spastic hip disease. J Bone Joint Surg Br. 2002 Jul;84(5):720-6.
• Hägglund G, Lauge-Pedersen H, Wagner P. Characteristics of children with hip displacement in cerebral palsy. BMC Musculoskeletal Disorder. 2007 Oct 26;8:101.
• Palisano R, Rosenbaum P, Walter S, Russell D, Wood E, Galuppi B. Development and reliability of a system to classify gross motor function in children with cerebral palsy. Dev Med Child Neurol. 1997 Apr;39(4):214-23.
• Kulkarni VA, Davids JR, Boyles AD, Cung NQ, Bagley A. Reliability and efficiency of three methods of calculating migration percentage on radiographs for hip surveillance in children with cerebral palsy. J Child Orthop. 2018 Apr 1;12(2):145-151.
• Boston Children’s Cerebral Palsy Hip Surveillance Screening Guide
  Bill Reid, The Royal Children’s Hospital, Melbourne, Australia. In Shrader MW, Wimberly L, Thompson R. Hip Surveillance in Children With Cerebral Palsy. J Am Acad Orthop Surg. 2019 Oct 15;27(20):760-768
• Kulkarni VA, Davids JR, Boyles AD, Cung NQ, Bagley A. Reliability and efficiency of three methods of calculating migration percentage on radiographs for hip surveillance in children with cerebral palsy. J Child Orthop. 2018 Apr 1;12(2):145-151