Involvement of valgus hindfoot deformity in hallux valgus deformity in rheumatoid arthritis

Characteristics of Intermetatarsal Angle Between the Second and Fifth Metatarsals (M2-M5A) in the Rheumatoid Foot

Background: Increasing of intermetatarsal angle between the first and second metatarsals (M1-M2A) has been reported as a risk factor for recurrence of hallux valgus (HV) deformity, on the other hand, increasing of intermetatarsal angle between the second and fifth metatarsals (M2-M5A) has been reported as a risk factor for resubluxation of the metatarsophalangeal (MTP) joint of the lesser toe after rheumatoid forefoot surgery. In this study, parameters related to increasing M2-M5A were investigated, as compared with M1-M2A and M1-M5A.

Methods: Radiographic parameters including M1-M2A, M1-M5A, and M2-M5A were retrospectively evaluated for 119 lower limbs from 68 patients with rheumatoid arthritis (RA). To clarify the clinical importance of these intermetatarsal angles, relationships with results from the timed up-and-go (TUG) test were also investigated.

Results: M1-M5A showed no correlation with mid-hind foot parameters, whereas M1-M2A and M2-M5A correlated with valgus/varus parameters. An increased M1-M2A was associated with lateral shift of the loading axis in the tibial plafond, whereas an increased M2-M5A was associated with medial shift, but M1-M5A showed no associations. M2-M5A/M1-M2A was significantly lower (1.7) in the normal TUG group than in the delayed TUG group (2.8) (p=0.045).

Conclusions: Different patterns of spread are seen for the forefoot. One has a predominantly increased M1-M2A with lateral shift of the loading point in the tibial plafond, whereas the other has a predominantly increased M2-M5A with medial shift of the loading point in the tibial plafond. M2-M5A also should be calculated, and M2-M5A/M1-M2A might be meaningful in understanding physical mobility in RA patients.

Impact of concurrent foot pain on health and functional status in people with knee osteoarthritis: data from the osteoarthritis initiative

OBJECTIVE

To document the prevalence of foot pain and foot pain laterality in people with knee osteoarthritis (OA) and to examine its impact on health and function.

METHODS

Participants from the Progression subcohort (n = 1,255, ages 45-79 years) of the Osteoarthritis Initiative with symptomatic tibiofemoral knee OA were included. Prevalence of foot pain, defined as pain in the foot/ankle, and foot pain laterality were determined. Health status was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index, the Short Form-12 Health Survey, and the Center for Epidemiological Studies Depression Scale. Function was assessed using the 20-meter walk test (WT) and a repeated chair stand test. Differences in health and functional measures were compared between groups with and without foot pain using multivariate analysis of covariance.

RESULTS

One-fourth (n = 317 [25%]) of people with knee OA experienced concurrent foot pain, with the majority (n = 174 [55%]) reporting pain in both feet. After adjusting for covariates, people with foot pain scored worse on all health measures and on the 20-meter WT, compared to those without (P < 0.05). Differences in health and function were found between the bilateral and ipsilateral foot pain groups compared to those without foot pain (P < 0.05), but no differences were found with the contralateral group.

CONCLUSION

Foot pain is common in people with knee OA, and bilateral and ipsilateral foot pain adversely affect health and function, suggesting laterality is important. Further research is needed to establish the mechanism and interaction of pathology at these sites and to evaluate foot pain treatment in this population.