Impact of multiple factors on the incidence of developmental dysplasia of the hip: risk assessment tool

Introduction: Developmental dysplasia of the hip (DDH) is one of the most common musculoskeletal conditions in children. Not treated DDH leads to disability, gait abnormalities, limb shortening and chronic pain. Our study aims to determine the impact of multiple risk factors on the occurrence of DDH and develop an interactive risk assessment tool.Materials and Methods: We conducted a retrospective cohort study in the Outpatient Clinic for Children of University Hospital. The Graf classification system was used for ultrasonographic universal screening. In total, 3102 infants met the eligibility criteria (n =6204 hip joints). Results: The incidence of DDH was 4.45%. In multivariate analysis, risk factors for DDH were weight (OR = 2.17 (1.41-3.32)), week of delivery (OR = 1.18 (1.00-1.37)), gender (OR = 8.16 (4.86-13.71)), breech delivery presentation (OR = 5.92 (3.37-10.40)), symptoms of DDH (25.28 (8.77-72.83)) and positive family history in siblings (5.74 (2.68-12.31)). Multivariate logistic regression predictive model was used to construct the interactive risk calculator.Conclusion: We confirmed well-known DDH risk factors in the studied population. Our results support the recent hypothesis that preterm infants (37 < week) have lower rate of DDH. The DDH risk calculator was built but needs external validation in prospective study before being used in a clinical setting.Level of Evidence: Retrospective cohort study: Level III

Analysis of Coronal And Sagittal Spinopelvic Parameters In Developmental Dysplasia of The Hip

Background: The observational study aimed to investigate the change and correlations of the spinopelvic parameters as well as the relationships with the related symptoms in unilateral developmental dysplasia of the hip (DDH) patients. Methods: The clinical data of 22 unilateral DDH patients and 20 healthy volunteers were collected from 2016 to 2021. All patients and volunteers were taken the antero-posterior pelvic radiograph and the frontal and lateral radiography of the whole spine as a routine examination. And the clinical symptoms, signs and functions were measured according to Oswestry Disability Index and Low Back Pain Scoring System. Then the t test and Pearson correlation were used to analyze the data. Results: The Cobb(8.68±6.21°), L3(4.79±5.47°), CB(1.65±1.57cm), PT(15.02±9.55°) and TLK (7.69±6.66°) were significantly larger in the DDH patients, whereas LL(37.41±17.17°) were significantly smaller (P＜0.05). As for the coronal spinopelvic parameters, CB was found to be associated with L3 (R=0.58, P＜0.01). Of the sagittal spinopelvic parameters, SS was found to be associated with LL (R=0.48, P=0.02), and TLK was found to be related to ST and TK, respectively (R=0.49, P=0.02; R=-0.45, P=0.04). In terms of relations between the spinal and pelvic parameters, PI were found to be related to the SS (R=0.58, P＜0.01). An analysis of relations revealed a correlation between the Oswestry Disability Index and Cobb(R=0.59, P＜0.01), PT(R=0.49, P=0.02), TK(R=-0.46, P=0.03) and TLK(R=0.44, P=0.04). Furthermore, an analysis of relations revealed a correlation between Low Back Pain Scoring System and Cobb (R=-0.44, P=0.04), L3(R=-0.53, P=0.01), PT (R=-0.44, P=0.04), TK(R=0.46, P=0.03) and TLK(R=-0.43, P=0.05). Conclusion: The parameters are related to each other and compensate each other to maintain the balance of the coronal and sagittal planes of the spine. In addition, the change of some parameters is closely related to the quality of life of the patients, and can provide some clues for the clinical diagnosis and treatment of DDH.

Prenatal murine skeletogenesis partially recovers from absent skeletal muscle as development progresses

Skeletal muscle contractions are critical for normal growth and morphogenesis of the skeleton, but it is unclear how the detrimental effects of absent muscle on the bones and joints change over time. Joint size, shape and cavitation, and rudiment length and mineralisation were assessed in multiple rudiments at two developmental stages (Theiler Stage (TS)24 and TS27) in the splotch-delayed 'muscleless limb' mouse model and littermate controls. As development progressed, the effects of absent muscle on all parameters except for cavitation become less severe. All major joints in muscleless limbs were qualitatively and quantitatively abnormal in shape at TS24, while, by TS27, most muscleless joint shapes were normal, or nearly normal. In contrast, any joints which were fused at TS24 did not cavitate by TS27. Therefore, recovery in joint shape over development occurred despite absent cavitation. Mineralisation showed the most pronounced changes between TS24 and TS27 in the muscleless limbs. At TS24, all muscleless rudiments studied had less mineralisation than the controls, while at TS27, muscleless limb rudiments had either the same or significantly more mineralisation than controls of the same age. We conclude that the effects of absent muscle on prenatal murine skeletogenesis are most pronounced in early skeletal development and reduce in severity prior to birth. Understanding how mammalian bones and joints continue to develop in an environment without muscle contractions, but with mechanical stimulation due to the movement of the mother, provides important insights into conditions affecting human babies such as developmental dysplasia of the hip and arthrogryposis.