Salvage arthrodesis for failed total ankle arthroplasty.

BACKGROUND AND PURPOSE: Total ankle arthroplasty (TAA) has gained popularity in recent years. If it fails, however, salvage arthrodesis must be reliable as a rescue procedure. We therefore investigated the clinical, radiographic, and subjective outcome after salvage arthrodesis in a consecutive group of patients, and concentrated on the influence of the method of fixation on union rate and on salvage in inflammatory joint disease. PATIENTS AND METHODS: Between 1994 and 2005, salvage arthrodesis was performed on 18 ankles (18 patients). Diagnosis was inflammatory joint disease (IJD) in 15 cases and osteoarthritis (OA) in 3. Tibio-talar fusion was performed in 7 ankles, and tibio-talocalcaneal fusion in 11. Serial radiographs were studied for time to union. Clinical outcome at latest follow-up was measured by the AOFAS score, the foot function index (FFI) and by VAS scores for pain, function, and satisfaction. RESULTS: Blade plates were used in 7 ankles (4 IJD, 3 OA); all united. Nonunion developed in 7 of the 11 rheumatic ankles stabilized by other methods. 11 patients (8 fused ankles, 3 nonunions) were available for clinical evaluation. Their mean AOFAS score was 62 and mean overall FFI was 70. VAS score for pain was 20, for function 64, and for satisfaction 74. The scores were similar in united and non-united ankles. INTERPRETATION: Blade plate fixation is successful in salvage arthrodesis for failed TAA. A high nonunion rate was found after salvage ankle arthrodesis in IJD with other methods of fixation. Clinical results were fair to good.

Low-Contact-Stress Knee Arthroplasty: Past History or Ahead of Time?

Low-contact-stress mobile-bearing (MB) total knee arthroplasty (TKA) can rely on a long history. Its concept comprises a combination of high condylar congruency and compensatory bearing rotation to promote load sharing. However, other MB designs have become available, and critical points have been raised about the benefit of MB in general. Although there is kinematic and kinetic support for the low-contact-stress concept, there is no tribologic or clinical proof of its superiority over fixed-bearing concepts. Further study should be controlled for differences in polyethylene quality and need to provide a measure of condylar congruency to differentiate authentic low-contact-stress variants form others. [Orthopedics. 2016; 39(3):e402-e412.].

Mobile-bearing total knee arthroplasty: More rotation is evident during more demanding tasks.

BACKGROUND: Some reports showed few but significant more axial femorotibial rotation in favor of mobile-bearing (MB) versus fixed-bearing (FB) total knee arthroplasty (TKA), mostly during knee bend fluoroscopic studies. The goal of the current study was to submit MB and FB groups of TKA patients to a turning activity, in which additional rotation was to be expected. METHODS: Two consecutive cohorts of patients after TKA (10 FB and 11 MB knees in a total of 18 patients) were assessed using motion analysis five year postoperatively, while performing gait and sit-to-walk (STW) movements with and without turning steps. RESULTS: Mean range of rotation in the FB group increased from 9.7° during gait, to 11.7° during STW straight, and to 14.3° during STW turning. Mean range of rotation in the MB group increased from 13.4° during gait to 21.0° during STW straight, and stayed at 21.1° during STW turning. CONCLUSIONS: Too many uncontrolled variables in the current study hinder a meaningful discrimination of MB from FB TKA rotation. However, the study does illustrate how more demanding task loads could be helpful in exploring the geometric constraints of TKA variants. LEVEL OF EVIDENCE: Level III, therapeutic study.