This retrospective cohort study compared the results of vascularised
and non-vascularised anterior sliding tibial grafts for the treatment
of osteoarthritis (OA)of the ankle secondary to osteonecrosis of
the talus. We reviewed the clinical and radiological outcomes of 27 patients
who underwent arthrodesis with either vascularised or non-vascularised
(conventional) grafts, comparing the outcomes (clinical scores,
proportion with successful union and time to union) between the
two groups. The clinical outcome was assessed using the Mazur and
American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot
scores. The mean follow-up was 35 months (24 to 68).Aims
Patients and Methods
A new method of vascularised tibial grafting
has been developed for the treatment of avascular necrosis (AVN)
of the talus and secondary osteoarthritis (OA) of the ankle. We
used 40 cadavers to identify the vascular anatomy of the distal
tibia in order to establish how to elevate a vascularised tibial
graft safely. Between 2008 and 2012, eight patients (three male,
five female, mean age 50 years; 26 to 68) with isolated AVN of the
talus and 12 patients (four male, eight female, mean age 58 years;
23 to 76) with secondary OA underwent vascularised bone grafting
from the distal tibia either to revascularise the talus or for arthrodesis.
The radiological and clinical outcomes were evaluated at a mean
follow-up of 31 months (24 to 62). The peri-malleolar arterial arch
was confirmed in the cadaveric study. A vascularised bone graft
could be elevated safely using the peri-malleolar pedicle. The clinical
outcomes for the group with AVN of the talus assessed with the mean
Mazur ankle grading scores, improved significantly from 39 points
(21 to 48) pre-operatively to 81 points (73 to 90) at the final
follow-up (p = 0.01). In all eight revascularisations, bone healing
was obtained without progression to talar collapse, and union was
established in 11 of 12 vascularised arthrodeses at a mean follow-up
of 34 months (24 to 58). MRI showed revascularisation of the talus
in all patients. We conclude that a vascularised tibial graft can be used both
for revascularisation of the talus and for the arthrodesis of the
ankle in patients with OA secondary to AVN of the talus. Cite this article:
A foreign-body-type host response can contribute to the induction and release of collagenolytic tissue-destructive enzymes of pathogenetic significance. Our aim was to analyse collagenase-3 in two conditions with putative involvement of foreign-body reactions. Synovial membrane-like tissue samples were obtained from cases of aseptic loosening of a total hip replacement (THR) and osteoarthritis (OA). The reverse transcription polymerase chain reaction (RT-PCR) disclosed that all the samples from patients contained collagenase-3 mRNA compared with only three out of ten control samples. The identity of the RT-PCR amplification product was confirmed by nucleotide sequencing. Immunohistochemical staining showed that collagenase-3 was present in endothelial cells, macrophages and fibroblasts, including those found in the synovial lining. This finding was confirmed by avidin-biotin-peroxidase complex-alkaline phosphatase-anti-alkaline phosphatase double staining and the specificity of the staining by antigen preabsorption using recombinant human collagenase-3. Collagenase-3 was released into the extracellular space and thus found in the synovial fluid in all patient samples as shown by Western blotting. The similar extent of collagenase-3 expression in aseptic loosening and OA compared with the low expression in control synovial membrane suggests involvement of a similar, foreign-body-based pathogenetic component in both. Comparative analysis of collagenase-3 and of foreign particles indicates that paracrine factors rather than phagocytosis We suggest that due to its localisation and substrate specificity, collagenase-3 may play a significant pathogenetic role in accelerating tissue destruction in OA and in aseptic loosening of a THR.
