The Alberta Congenital Anomalies Surveillance System: a 40-year review with prevalence and trends for selected congenital anomalies, 1997-2019. / Le système de surveillance des anomalies congénitales de l'Alberta : compte rendu des données sur 40 ans avec prévalence et tendances de certaines anomalies congénitales entre 1997 et 2019.

INTRODUCTION: Current published long-term provincial or territorial congenital anomaly data are lacking for Canada. We report on prevalence (per 1000 total births) and trends in 1997-2019, in Alberta, Canada, for selected congenital anomalies. Associated risk factors are also discussed. METHODS: We used data from the Alberta Congenital Anomalies Surveillance System (ACASS) to calculate the prevalence and perform chi-square linear trend analyses. RESULTS: From 1997 to 2019, the overall prevalence of neural tube defects was stable, at 0.74 per 1000 total births. The same was true for spina bifida (0.38), orofacial clefts (1.99), more severe CHDs (transposition of the great arteries, 0.38; tetralogy of Fallot, 0.33; and hypoplastic left heart syndrome, 0.32); and gastroschisis (0.38). Anencephaly, cleft palate and anorectal malformation significantly decreased with a prevalence of 0.23, 0.75 and 0.54 per 1000 total births, respectively. Significantly increasing trends were reported for anotia/microtia (0.24), limb reduction anomalies (0.73), omphalocele (0.36) and Down syndrome (2.21) and for hypospadias and undescended testes (4.68 and 5.29, respectively, per 1000 male births). CONCLUSION: Congenital anomalies are an important public health concern with significant social and societal costs. Surveillance data gathered by ACASS for over 40 years can be used for planning and policy decisions and the evaluation of prevention strategies. Contributing genetic and environmental factors are discussed as is the need for continued surveillance and research.

Congenital limb deficiencies and major associated anomalies in Alberta for the years 1980-2012.

There is a wide range of the proportion of congenital anomalies associated with limb deficiencies reported in the literature. This variation is primarily attributed to methodology and classification differences. The distribution of associated anomalies among cases with congenital limb deficiencies in Alberta born between January 1, 1980 and December 31, 2012 is described. Of the 170 cases identified, most were live born (75.3%), male (61.8%), had longitudinal limb deficiencies (78.8%), and had associated anomalies outside the musculoskeletal system (77.6%). Significant associations between the preaxial longitudinal group and the central nervous, gastrointestinal, and cardiovascular systems are reported as well as between the postaxial longitudinal group and congenital hip and foot anomalies. Probable and possible syndrome diagnoses are described for cases with recognized malformation patterns.

Views on the Oberg-Manske-Tonkin Classification System for Congenital Anomalies of the Hand and Upper Limb.

A new classification system was proposed by Tonkin et al as a replacement for the Swanson/International Federation of Societies for Surgery of the Hand system. We have reviewed their aims and have pointed out a number of problems that will make it difficult to be universally accepted.

Congenital limb deficiencies in Alberta-a review of 33 years (1980-2012) from the Alberta Congenital Anomalies Surveillance System (ACASS).

The birth prevalence of limb deficiencies in Alberta has been fluctuating. The objectives were to examine patterns and temporal trends of congenital limb deficiencies in Alberta and compare rates with those of other jurisdictions. The Alberta Congenital Anomalies Surveillance System data on live births, stillbirths, and terminations of pregnancy (<20 weeks gestation) occurring between 1980 through 2012 with the ICD-10 Royal College of Paediatrics and Child Health Adaptations codes Q71-Q73 (limb reduction defects), Q79.80 (congenital constriction bands), and Q87.24 (sirenomelia syndrome) were reviewed. Cases were classified as having amelia, transverse, longitudinal (preaxial, postaxial, central, or mixed), intercalary, split hand/split foot, complex, or other type of limb deficiency. Phenotypes were classified as associated, which included cases with a known etiology and cases with at least one other type of anomaly, or isolated. From 1980 through 2012, 795 cases were ascertained from 1,411,652 live births and stillbirths, giving a prevalence of 5.6/10,000 total births. Mixed longitudinal deficiencies were the most common (22.4%). The upper limbs (63.9%) were affected more often than the lower limbs (25.3%). Isolated limb deficiencies occurred in 43.6% of cases, 28.4% had Mendelian or other known conditions, 21.9% had multiple congenital anomalies, 5.4% had chromosome abnormalities and 0.6% were due to teratogens. The associated group, showed a significant increasing trend (P = 0.023). While the overall limb deficiency rates show very little differences across diverse populations and differing time periods, comparisons of subgroups should be made with caution, because variations in terminology and classification contribute to reported differences.

Principles of rotationplasty.

Rotationplasty is a reconstructive, limb-sparing option for management of lower extremity bone deficiency. This technique involves an intercalary resection, followed by 180° rotation of the distal limb to allow the ankle to function as a knee joint when it is fitted with a modified below-knee prosthesis. Gait analysis and functional outcome studies have reported favorable results with rotationplasty compared with those of above-knee amputation. Moreover, patient satisfaction with rotationplasty is higher than with other limb salvage procedures. The primary drawback of this procedure is patient acceptance of the limb's appearance.

Physeal bridge resection.

Growth arrest secondary to physeal bridge formation is an uncommon but well-recognized complication of physeal fractures and other injuries. Regardless of the underlying etiology, physeal bridges may cause angular and/or longitudinal growth disturbances, with progression dependent on the remaining physeal growth potential. Physeal bridge resection and insertion of interposition material releases the tethering effect of the bridge. Physeal bridge resection has become an accepted treatment option for patients with existing or developing deformity and for those with at least 2 years or 2 cm of growth remaining. Current experimental research is focused on the use of gene therapy and other factors that enhance chondrocyte proliferation to improve the management of growth arrest. The use of cartilage and cultured chondrocytes as interposition material after physeal bridge resection is an area of active research.