Amelioration in Ankle Pain and Improvement in Function After Total Knee Arthroplasty for Ipsilateral Knee and Ankle Osteoarthritis: A Report of Two Cases

Midterm Outcomes After Total Knee Arthroplasty With Lateral Approach for Valgus Knee Deformity in Patients With Rheumatoid Arthritis

Background Valgus knee deformity is often seen in rheumatoid arthritis (RA) cases. Usually, the medial approach has been often utilized for total knee arthroplasty (TKA), even in valgus deformity cases; however, the medial approach is feared to induce further instability in the medial side because it could further break the soft tissue structure, including medial collateral ligament (MCL) and medial patellofemoral ligament (MPFL). Consequently, loosening of the implant, recurrence of valgus knee deformity, and pain due to instability might be induced in the early period after surgery. In this study, a lateral approach for TKA against valgus deformity in RA cases was utilized to avoid further damage on the medial side. Methods Eleven valgus knees in 10 patients with RA (mean age, 61.1 years; mean follow-up, 33.1 months) underwent primary TKA with the lateral approach. Iliotibial band (ITB) dissection and/or peroneal nerve release were performed if necessary. Radiological and clinical investigations were evaluated pre- and postoperatively. Results The average operating time was 106 minutes, which was no longer compared with the time after the medial approach described previously. The extension angle was significantly improved from -15.0 ± 10.2 to -5.5 ± 4.2 degrees (P = 0.03), while the flexion angle showed no significant change (from 111.8 ± 15.9 to 115.0 ± 13.2 degrees). The hip-knee-ankle angle (HKA) was also significantly corrected from -9 ± 4.9 to 0.4 ± 1.7 degrees (P < 0.001). The 2011 Knee Score System (KSS) scores were significantly improved from 6.9 ± 3.4 to 21.5 ± 2.9 (P < 0.001) in symptoms, from 15.6 ± 2.7 to 31.1 ± 4.1 (P < 0.001) in satisfaction, and from 31.5 to 59.5 (P < 0.01) in activity. Conclusion Midterm outcomes after lateral approach TKA were good, and knee alignment was significantly improved. The lateral approach TKA for valgus deformity in patients with RA was not complicated and difficult because it required no additional operating time compared with the medial approach. From the perspective of preventing further damage to the soft tissue structure on the medial side, the lateral approach was meaningful for valgus deformity in patients with RA.

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.

Improvement of Knee Alignment and Function After Corrective Surgery for Hindfoot Deformity: A Report of 3 Cases

CASE

Marked varus or valgus hindfoot deformities in 3 patients with ankle osteoarthritis or rheumatoid arthritis were treated by corrective surgery using total ankle arthroplasty or distal tibia oblique osteotomy. All cases achieved not only sufficient correction and satisfactory clinical/radiographic hindfoot improvement but also improvements in both knee alignment and function.

CONCLUSION

Corrective surgery for hindfoot deformity can potentially change or improve ipsilateral knee alignment and function, representing an unexpected benefit of hindfoot realignment.

Association of Decreased Physical Activity with Rheumatoid Mid-Hindfoot Deformity/Destruction

Foot/ankle problems remain important issues in rheumatoid arthritis (RA) patients. Although forefoot deformity generally takes a major place in surgical treatment, concomitant mid-hindfoot deformity is also commonly seen. In this situation, it can be easy to overlook that mid-hindfoot deformity can also induce or exacerbate clinical problems behind the forefoot events. Thus, the relationship between mid-hindfoot deformity/destruction and physical activity/ADL was investigated. Radiographic findings of 101 lower limbs (59 patients) were retrospectively evaluated. Alignment parameters in the lower extremity and joint destruction grade (Larsen grade) were measured. The timed-up-and-go (TUG) test, modified health assessment questionnaire (mHAQ), pain, self-reported scores for the foot and ankle (SAFE-Q), and RA disease activity were investigated to assess clinical status. The relationships among these parameters were evaluated. Subtalar joint destruction was correlated with TUG time (r = 0.329), mHAQ score (r = 0.338), and SAFE-Q: social functioning (r = 0.332). TUG time was correlated with the HKA (r = −0.527), talo-1st metatarsal angle (r = 0.64), calcaneal pitch angle (r = −0.433), M1-M5A (r = −0.345), and M2-M5A (r = −0.475). On multivariable linear regression analysis, TUG time had a relatively strong correlation with the talo-1st metatarsal angle (β = 0.452), and was negatively correlated with calcaneal pitch angle (β = −0.326). Ankle joint destruction was also correlated with TUG time (β = 0.214). Development of structural problems or conditions in mid-hindfoot, especially flatfoot deformity, were related with decreased physical activity in RA patients. Wearing an insole (arch support) as a preventative measure and short foot exercise should be considered from the early phase of deformity/destruction in the mid-hindfoot in the management of RA.