Physical Capacity Among Patients Treated With Periacetabular Osteotomy for Hip Dysplasia: a Cross-sectional Study
Condition: Hip Dysplasia; Joint Diseases; Musculoskeletal Diseases
MeSH terms: Joint Diseases; Musculoskeletal Diseases; Hip Dislocation; Developmental Dysplasia of the Hip; Hip Dislocation, Congenital; Hyperplasia
Study type: Observational

Summary: 
      This cross-sectional study investigates the physical capacity of patients, who have undergone
      a periacetabular osteotomy for hip dysplasia within the last 1-5 years.
    

Detailed description: 
      Hip dysplasia is a common disease both worldwide and among the Danish population. The disease
      is characterized by a shallow and oblique acetabulum, resulting in insufficient coverage of
      the femoral head. The abnormalities of the dysplastic hip joint lead to altered biomechanical
      adaptations, highly affecting the physical capacity of patients. Studies have shown that
      patients with hip dysplasia experience reduced muscle strength and gait abnormalities, when
      compared to healthy controls.

      Each year, approximately 200 Danes with hip dysplasia are treated with periacetabular
      osteotomy (PAO). As the preferable joint-preserving surgical treatment for younger patients
      with symptomatic hip dysplasia, the PAO reduces prevalence of muscle-tendon-related pain and
      improves hip and groin related patient-reported outcome measures (PROMs). By extension,
      studies report a hip survival rate of approximately 75% 12 years following PAO.

      However, little is known about objective measures of physical capacity following PAO. Despite
      reducing muscle-tendon-related pain and improving PROMs, gait adaptations still remain and
      studies report no improvements in muscle strength, nor in the physical activity profile, 1
      year following treatment with PAO. Thus, the field calls for research aiming to identify
      parameters of impaired physical capacity in patients treated with PAO. Thorough knowledge of
      physical capacity in these patients may contribute to the establishment of a science-based
      rehabilitation strategy, potentially improving physical activity, function, work capacity and
      quality of life.

      The primary aim of this study is to analyse and identify parameters of impaired physical
      capacity in patients with hip dysplasia 1-5 years following treatment with PAO. Gait
      function, defined as peak hip extension angle and peak hip flexor moment, is chosen as the
      primary outcome, due to previously shown correlations between the extent of gait impairments
      and the Copenhagen Hip and Groin Outcome Score (HAGOS).

      As recommended by the International Hip-related Pain Research Network (IHiPRN), measurements
      of physical capacity in patients with hip-related pain should include: clinical measures,
      laboratory-based measures, measures of physical activity and return to physical activity.
      Secondary outcomes of this study are: muscle activity during level walking and walking with
      inclination, endurance and pain during walking, range of motion (ROM), muscle strength, hip
      and muscle-tendon-related pain, radiographic measures and PROMs (present level of physical
      activity and sports & activity level prior to and after treatment with PAO).

      We hypothesise that patients with the lowest scores of HAGOS subscales pain and
      sport/recreation will have the lowest physical capacity, measured as: gait impairments,
      reduced muscle strength and prevalence of muscle-tendon-related pain.

      This is a cross-sectional study.

      Thirty subjects from across the country, aged 18-40 years, who have undergone a PAO for hip
      dysplasia within the last 1-5 years, will be included in the study.

      All testing will be performed at Copenhagen University Hospital, Hvidovre.
    

Intervention name(s): Testing of physical capacity
Intervention type(s): Other
Intervention description(s): This cross-sectional study will involve evaluation of physical capacity by assessment of:
Gait function
Muscle activity during walking
Endurance during walking
Hip muscle strength
Hip range of motion
Hip and muscle-tendon-related groin pain
Hip and groin related patient-reported outcome measures (PROMs)
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Subjects who have undergone a periacetabular osteotomy (PAO) for hip dysplasia within the
        last 1-5 years.

        Subjects will be recruited through social media from two specific closed-member facebook
        groups for patients with hip dysplasia. Permission for recruiting through social media was
        granted by The Danish Data Protection Agency along with permission for the handling of
        personal data (P-2020-261).
      
Keywords: Hip Dysplasia; Hip and muscle-tendon related groin pain; Musculoskeletal Diseases