Meta-analysis of erosive hand osteoarthritis identifies four common variants that associate with relatively large effect

OBJECTIVES

Erosive hand osteoarthritis (EHOA) is a severe subset of hand osteoarthritis (OA). It is unclear if EHOA is genetically different from other forms of OA. Sequence variants at ten loci have been associated with hand OA but none with EHOA.

METHODS

We performed meta-analysis of EHOA in 1484 cases and 550 680 controls, from 5 populations. To identify causal genes, we performed eQTL and plasma pQTL analyses, and developed one zebrafish mutant. We analysed associations of variants with other traits and estimated shared genetics between EHOA and other traits.

RESULTS

Four common sequence variants associated with EHOA, all with relatively high effect. Rs17013495 (SPP1/MEPE, OR=1.40, p=8.4×10^-14) and rs11243284 (6p24.3, OR=1.35, p=4.2×10^-11) have not been associated with OA, whereas rs11631127 (ALDH1A2, OR=1.46, p=7.1×10^-18), and rs1800801 (MGP, OR=1.37, p=3.6×10^-13) have previously been associated with hand OA. The association of rs1800801 (MGP) was consistent with a recessive mode of inheritance in contrast to its additive association with hand OA (OR homozygotes vs non-carriers=2.01, 95% CI 1.71 to 2.37). All four variants associated nominally with finger OA, although with substantially lower effect. We found shared genetic components between EHOA and other OA measures, grip strength, urate levels and gout, but not rheumatoid arthritis. We identified ALDH1A2, MGP and BMP6 as causal genes for EHOA, with loss-of-function Bmp6 zebrafish mutants displaying EHOA-like phenotypes.

CONCLUSIONS

We report on significant genetic associations with EHOA. The results support the view of EHOA as a form of severe hand OA and partly separate it from OA in larger joints.

Evaluation of factors influencing surgical treatment costs for distal biceps rupture

BACKGROUND

Given the similar outcomes of various fixation constructs for single-incision distal biceps repair, a critical evaluation of the factors that drive the cost of the procedure is the key to optimizing treatment value. The purpose of this study was to quantify variation in costs for surgical treatment of complete distal biceps ruptures, as well as identify factors affecting costs.

METHODS

We retrospectively identified adult patients consecutively treated surgically for complete distal biceps ruptures between July 2011 and January 2018 at a single academic medical center. Using our institution's information technology value tool, we recorded the surgical encounter total direct costs (SETDCs) for each patient. Univariate and multivariate gamma regression models were used to determine factors affecting SETDCs.

RESULTS

Of 121 included patients, 102 (86%), 7 (6%), and 12 (10%) underwent primary repair, revision, and reconstruction. SETDCs varied widely, with a standard deviation of 40% and a range of 58% to 276% of the average SETDC. The main contributors to SETDCs were facility utilization costs (53%) and implant costs (29%). Implant costs also varied, with a standard deviation of 16%, ranging up to 121% of the mean SETDC. Multivariate analysis demonstrated that reconstructions were 72% more costly than primary repairs (P < .001). No significant cost differences were found between cortical button and dual-suture anchor fixation (P = .058). American Society of Anesthesiologists class, body mass index, revision surgery, time to surgery, location, administration of postoperative block, and surgeon performing the procedure did not significantly affect the SETDC.

CONCLUSION

Surgical encounter and implant costs vary widely for distal biceps rupture treatment. However, no significant difference in SETDC was identified between repair with a cortical button vs. dual-suture anchor repair. The greater costs associated with reconstruction surgery should be taken into consideration.