Using Registries to Investigate Rare Diseases
There has been a huge worldwide effort over the last 2-plus decades to establish arthroplasty registries. Among the many advantages of such registries, advocates emphasize the potential detection of early failures associated with new implant designs and biomaterials. The large number of patients enrolled in most registries and the methodical capturing of data yield substantial statistical and research benefits.
Based on the successes of arthroplasty registries, parallel registries have been established for sports medicine (especially for shoulder and knee conditions and treatments), fractures, musculoskeletal tumors, and others. Although the focus has been on enrolling large numbers of patients with relatively common disorders or procedures, there have been less well-publicized efforts to create smaller registries of rarer diseases.
In the October 21, 2020 issue of The Journal, Forman et al. use the 8-site Congenital Upper Limb Differences (CoULD) registry to report on associations between congenital deficiency of the radial aspect of the forearm in 259 patients (383 involved limbs) and thumb hypoplasia. Two findings stood out to me:
- The severity of radial deficiency was correlated with the severity of thumb deficiency.
- Compared with subjects who had no diagnosed syndromes, patients with concomitant syndromes (such as VACTERL and Holt-Oram) were twice as likely to have bilateral deficiency and 2.5 times as likely to have radial and thumb deficiencies as opposed to thumb deficiency alone.
In addition to reinforcing findings from previous single-institution studies, these data from Forman et al. will help surgeons counsel parents, determine treatment approaches, and establish frameworks for following patient outcomes after both surgical and nonsurgical treatment. It is my hope that other clinician-researchers with interest in understanding and managing rare conditions will establish similar registries to benefit these smaller but no-less-important groups of patients and families.
Click here to read the JBJS Clinical Summary on Congenital Hand Differences.
Marc Swiontkowski, MD