Patient-Reported Outcomes, Function, and Gait Mechanics After Fixed and Mobile-Bearing Total Ankle Replacement.

The popularity of total ankle replacement as a treatment for end-stage arthritis continues to grow. The purpose of this study was to assess changes in ankle kinetics and kinematics from a preoperative time point through two years postoperatively in patients who had received either a fixed-bearing or a mobile-bearing implant. Ninety patients who received a primary total ankle replacement (forty-nine mobile-bearing and forty-one fixed-bearing) were examined. Three-dimensional joint mechanics and ground reaction forces were measured during level walking preoperatively and one and two years postoperatively. Patient-reported and functional outcomes were also collected. Data were analyzed with use of a 3 × 2 repeated-measures analysis of variance (ANOVA) to determine significant differences between implant types and across time (α = 0.05). No significant difference was observed in the ankle motion or step time between implant types or across time. However, there was a greater increase in the peak plantar flexion moment and the Short Form-36 (SF-36) total score across time in the fixed-bearing group than in the mobile-bearing group. Conversely, visual analog scale (VAS) pain scores exhibited greater improvement in the mobile-bearing group than in the fixed-bearing group. Independent of implant type, a significant improvement was observed in walking speed, results of the functional tests, spatiotemporal variables, patient-reported outcomes, and vertical ground reaction forces. Independent of time, the fixed-bearing group demonstrated a significant increase in both the weight-acceptance and the propulsion ground reaction forces compared with the mobile-bearing group. The mobile-bearing group completed the Sit-to-Stand test significantly faster. All of the observed changes suggest improved or maintenance of function following total ankle replacement. In general, the group with a fixed-bearing implant demonstrated improvements in ankle moment and ground reaction forces, while the mobile-bearing-implant group demonstrated improvements in patient-reported pain outcome. There were few significant changes between the two implant types. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Queen RM ，Sparling TL ，Butler RJ ，Adams SB Jr ，DeOrio JK ，Easley ME ，Nunley JA ... -  《-》

Are There Differences in Gait Mechanics in Patients With A Fixed Versus Mobile Bearing Total Ankle Arthroplasty? A Randomized Trial.

Queen RM ，Franck CT ，Schmitt D ，Adams SB ... -  《-》

J. Leonard Goldner Award 2011: changes in pain, function, and gait mechanics two years following total ankle arthroplasty performed with two modern fixed-bearing prostheses.

Queen RM ，De Biassio JC ，Butler RJ ，DeOrio JK ，Easley ME ，Nunley JA ... -  《-》

Early to mid-term results of fixed-bearing total ankle arthroplasty with a modular intramedullary tibial component.

There has been a continuing increase in the use of total ankle arthroplasty for the treatment of end-stage ankle arthritis. Our aim was to determine the clinical, radiographic, and functional outcomes of total ankle arthroplasties done with a prosthesis with a modular intramedullary stem and intramedullary referencing to align the tibia. A consecutive series of patients who underwent total ankle arthroplasty with the INBONE Total Ankle Replacement from June 2007 to December 2010 were enrolled in this study. Pain and patient-reported function were assessed with use of a visual analog scale (VAS) for pain, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, the Short Musculoskeletal Function Assessment (SMFA), and the Short Form-36 (SF-36) Health Survey. Objective function was measured with assessment of walking speed, the Timed Up and Go (TUG) test, the Sit-to-Stand (STS) test, and the Four Square Step Test (4SST). Standardized weight-bearing radiographs obtained preoperatively and after total ankle arthroplasty were evaluated. We analyzed clinical, functional, and radiographic measurements with a series of repeated-measures analyses of variance (ANOVAs) with post-hoc testing to assess differences between preoperative, one-year postoperative, and most recent follow-up data. On the basis of the number of statistical comparisons, a Bonferroni correction was completed (alpha < 0.003). We identified 194 primary INBONE total ankle arthroplasties with a mean duration of clinical follow-up of 3.7 years (range, 2.2 to 5.5 years). Patients demonstrated a significant improvement (p < 0.003) in VAS pain, AOFAS, SMFA, and SF-36 scores at the time of final follow-up, compared with preoperative values, and in walking speed, STS time, TUG time, and 4SST time at two years postoperatively, compared with preoperatively. The mean coronal tibiotalar angle for varus and valgus ankles significantly improved postoperatively and was maintained until the time of final follow-up. The prevalence of unstable subsidence leading to impending failure was 5%, and the prevalence of revision was 6%. Patients who underwent total ankle arthroplasty with the INBONE Total Ankle Replacement demonstrated significant improvement in radiographic, functional, and patient-reported outcome scores at a mean of 3.7 years postoperatively. The overall implant survival rate was 89%. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Adams SB Jr ，Demetracopoulos CA ，Queen RM ，Easley ME ，DeOrio JK ，Nunley JA ... -  《-》

The effect of tibiotalar alignment on coronal plane mechanics following total ankle replacement.

Gait mechanics following total ankle replacement (TAR) have reported improved ankle motion following surgery. However, no studies have addressed the impact of preoperative radiographic tibiotalar alignment on post-TAR gait mechanics. We therefore investigated whether preoperative tibiotalar alignment (varus, valgus, or neutral) resulted in significantly different coronal plane mechanics or ground reaction forces post-TAR. We conducted a non-randomized study of 93 consecutive end-stage ankle arthritis patients. Standard weight-bearing radiographs were obtained preoperatively to categorize patients as having neutral (±4°), varus (≥5° of varus), or valgus (≥5° of valgus) coronal plane tibiotalar alignment. All patients underwent a standard walking assessment including three-dimensional lower extremity kinetics and kinematics preoperatively, 12 and 24 months postoperatively. A significant group by time interaction was observed for the propulsive vertical ground reaction force (vGRF), coronal plane hip range of motion (ROM) and the peak hip abduction moment. The valgus group demonstrated an increase in the peak knee adduction angle and knee adduction angle at heel strike when compared to the other groups. Coronal plane ankle ROM, knee and hip angles at heel strike, and the peak hip angle exhibited significant increases across time. Peak ankle inversion moment, peak knee abduction moment and the weight acceptance vGRF also exhibited significant increases across time. Neutral ankle alignment was achieved for all patients by 2 years following TAR. Restoration of neutral ankle alignment at the time of TAR in patients with preoperative varus or valgus tibiotalar alignment resulted in biomechanics similar to those of patients with neutral preoperative tibiotalar alignment by 24-month follow-up.

Grier AJ ，Schmitt AC ，Adams SB ，Queen RM ... -  《-》