Total Ankle Replacement in Cavovarus Deformity: How Far Can We Go?

Because of the good functional results and satisfactory implant survival achieved with modern models, total ankle replacement (TAR) has become a legitimate alternative to ankle fusion. However, alignment and balance are mandatory for implant survival. Satisfactory results can be achieved in patients with significant preoperative deformity if alignment and balance were obtained. If not, a staged procedure involving deformity correction and secondary TAR is possible. The authors describe the principal aspects of this concept and illustrate their current approach to TAR in cavovarus deformity.

Impact of intertibiofibular graft on the ankle joint: Medium-term radiologic and clinical assessment.

HYPOTHESIS: Intertibiofibular graft (ITFG) bridges tibial non-union, but blocks bimalleolar mortise opening, leading to loss of ankle dorsiflexion. The aim of the present study was to assess dorsiflexion loss and to determine whether it was associated with secondary osteoarthritis. Material and method A 2-center retrospective study included cases of tibial non-union, without initial involvement of the ankle, treated by ITFG with more than 2 years' consolidation. Clinical, functional and radiographic parameters were analyzed. Dorsiflexion stiffness was defined as<10° flexion. Symptomatic osteoarthritis was defined by radiologic joint impingement and/or osteophytosis associated with pain>4/10 on visual analog scale (VAS) restricting walking distance to less than 1 kilometer. RESULTS: Thirty-one cases were analyzed at a mean 7±2.8 years' follow-up. Mean pain on VAS was 3±2.6. Mean AOFAS score was 62.3±20.5 and mean SEFAS was 28.3±10.5. Mean dorsiflexion was significantly lower on the ITFG side, at 6.6±7.9° versus 15.1±4.8° on the healthy side. There was dorsiflexion stiffness in 26 cases. No correlation emerged between dorsiflexion stiffness and onset of osteoarthritis. CONCLUSION: Dorsiflexion was the most severely impacted motion. The rate of osteoarthritis was too low for any implication of dorsiflexion loss to be demonstrated, especially in traumatic contexts. LEVEL OF EVIDENCE: IV; retrospective study.

Influence of offset stem couplers in femoral revision knee arthroplasty: a radiographic study.

We questioned whether the use of offset femoral stem would result in modifying the posterior femoral condylar offset (PFCO) in revision knee arthroplasty (RTKA). We measured both PFCO and stem alignment on lateral radiographs of two cohorts: 91 knees with straight stems and 35 knees with offset coupled stems. A higher PCOR was observed in knees with an offset stem compared to knees with straight stem. Knees with an offset stem had a better alignment within the intramedullary canal. Our conclusion is that the use of a modular offset coupler with femoral stem in RTKA compared to a modular straight stem both increases the posterior condylar offset and improves alignment of the stem within the intramedullary canal.

Posteriorly offset femoral component to restore anteroposterior position of the distal femur in revision total knee arthroplasty.

This study is based on a radiographic analysis of 50 cadaveric femurs (26 males, 24 females). The position of a press-fit stemmed revision total knee arthroplasty femoral component was simulated with templates. A diaphyseal engaging stem was templated in 74% of the subjects (23 males, 14 females). Every diaphyseal engaging stem required the use of a posterior offset coupler to achieve engagement in the femoral isthmus. In 26% of femurs (3 males, 10 females), anterior bowing of the distal metaphysis prevented the use of a diaphyseal engaging stem. Our results suggest that males have less flexion of the distal femur than females and can be templated effectively with a diaphyseal engaging posteriorly offset stem, whereas a metaphyseal flexed stemmed component templates better in females.