Aiko Sakurai

Stress fracture of the first metatarsal after total knee arthroplasty: Two case reports using gait analysis

Stress fractures after total knee arthroplasty (TKA) occur mainly in patients with considerable deformity of the knee. In addition, the majority of these fractures after TKA involve the hip joint. We present two cases of stress fractures of the first metatarsal after TKA in patients with severe varus deformity. Correction of leg alignment and pain reduction obtained by TKA lead to stress fracture of the bone. Gait analysis was carried out for both cases in order to clarify the gait characteristics of the stress fracture. As a result, side-to-side differences of the distance between first metatarsal and foot center of pressure in the coronal plane were observed using gait analysis in these patients. Fortunately, conservative treatment was successful for these patients. Stress fractures should be considered when a patient who had a considerable severe deformity of the knee preoperatively complains of foot pain on the affected side. Contrary to stress fractures at the hip joint, patients with the fracture of the first metatarsal can be treated without surgery.

Effect of unstable meniscal injury on three-dimensional knee kinematics during gait in anterior cruciate ligament-deficient patients.

BACKGROUND Our purpose was to clarify the differences of three-dimensional knee kinematics in anterior cruciate ligament (ACL)-deficient patients between with and without meniscal injury using gait analysis. METHODS A total of 72 knees in 36 young athletes with primary and unilateral ACL injury, with a mean age of 22 years, participated. Gait analysis was done before surgery. According to the arthroscopic findings, patients were divided into two groups. The patients with an unstable meniscal tear were allocated to the meniscal injury group (ACL+M group), and the patients without a meniscal tear were allocated to the no meniscal injury group (ACL group). In the gait analysis, three-dimensional knee kinematics was evaluated and compared. RESULTS The patients in both groups exhibited lower sagittal plane knee excursions and peak knee extension angles on the affected limb than on the unaffected limb during the mid-stance. In terms of the axial plane, a rotation angle was significantly smaller in the affected knees than in the unaffected knees in the ACL group. On the other hand, an opposite phenomenon was observed in the ACL+M group. Moreover, a significantly larger rotation angle in the affected knees during the stance phase and the whole gait cycle was observed in the ACL+M group than in the ACL group. CONCLUSION Increased rotational motion during the gait was observed in the ACL-deficient knees combined with unstable meniscal injuries. Meniscal condition may be a key factor for compensatory gait mechanics to prevent rotatory instability in ACL-deficient patients patients. LEVEL OF EVIDENCE III.

Factors affecting one-leg standing time in patients with end-stage knee osteoarthritis and the age-related recovery process following total knee arthroplasty.

BackgroundThe aims of the present study were to investigate the factors affecting one-leg standing (OLS) time in patients with end-stage knee osteoarthritis (OA) and to clarify the age-related recovery process following total knee arthroplasty (TKA) in the early postoperative period.MethodsA total of 80 knees of 40 patients with knee OA were enrolled. They were asked to perform relaxed standing on one leg for as long as possible. First, OLS time was measured. Second, age, body mass index, knee flexion angle during (KFA) OLS, femorotibial angle (FTA) during OLS, and a visual analogue scale (VAS) for pain were evaluated. Multiple regression analysis was done to identify the factors affecting OLS time. In addition, the recovery process was compared between older and younger patients after TKA.ResultsA larger KFA during OLS, older age, and larger FTA were significantly associated with shorter OLS time. After TKA, postoperative OLS time in older patients did not improve significantly by postoperative day 20, while the time in younger patients improved significantly from postoperative day 19.ConclusionsEven if subjective knee pain and KFA during OLS improved, longer rehabilitation was required to improve OLS time in older patients in the early postoperative period.

Three-dimensional knee kinematics in patients with a discoid lateral meniscus during gait

BACKGROUND To date, the knee kinematics of a discoid lateral meniscus (DLM) has not been elucidated. The aim was to investigate the three-dimensional knee kinematics in knees with a DLM using gait analysis. METHODS Ten patients (mean: 14years) diagnosed with bilateral DLM and unilaterally symptomatic snapping as well as 10 healthy controls (mean: 23years) participated in the study. Each patient with a DLM had unilaterally snapping knee in full extension and deep flexion. The three-dimensional gait analysis was performed with the point cluster technique. All subjects were asked to walk on a level floor at the speed of their choice. In the sagittal plane, knee excursion was separately evaluated during the weight acceptance phase and the mid-stance phase. In the axial plane, knee excursion during the stance phase was assessed. Finally, knee excursion during the whole gait cycle was evaluated in the frontal plane. Statistical comparison was conducted between groups, and between both sides in the DLM group. RESULTS In the sagittal plane, knee excursions during the weight acceptance phase and the mid-stance phase were significantly smaller in the DLM group than in the control group; in addition, these were smaller on the symptomatic side than on the asymptomatic side in the DLM group. In the axial plane, knee excursion was also significantly smaller on the symptomatic side than on the asymptomatic side in the DLM group, whereas the frontal knee motion did not differ significantly. CONCLUSION Less knee motion in the sagittal plane may prevent snapping during extension and flexion in patients with a DLM. LEVEL OF EVIDENCE III.