Foot & Ankle

Allograft versus autograft in talar defects

Osteochondral lesions of the talus are a relatively common presentation. Arthroscopic evaluation of ankles following fracture has suggested that upwards of 30% of patients present with an osteochondral defect – and this is aside from those presenting with large traumatic osteochondral defects of the talus or with degenerative changes to the talus. The results of regenerative surgery, be it microfracture or osteochondral grafting, have been mixed. This paper from New York, New York (USA) compares two of the available options to treat osteochondral defects: allograft and autograft.¹ The authors undertook a retrospective analysis of 16 patients who received allograft and 25 patients who received autograft for an osteochondral defect of the talus. Outcomes were assessed using radiographs, clinical records, and outcome scores, including the Foot and Ankle Outcome Score (FAOS) and the 12-Item Short-Form Health Survey (SF-12) score. Where available, MRI scans were assessed using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Outcomes were assessed at a mean follow-up of just over two years, and there were no differences to be found between the cohorts in terms of demographic factors. However, this was not the case with the functional scores, for which the authors established that the patients in the autograft group did better in almost every outcome measure. The FAOS was significantly better in the autograft group (81.9 vs 70.1), as was the SF-12 (74.7 vs 61.2). From the imaging perspective, the authors established that the MOCART scores were also reflective of superior outcomes in the autograft group (87.1) than in the allograft group (75.5). Based on a comprehensive assessment of their relatively large (but non-randomized) series, the authors conclude that autograft is superior to allograft in almost every postoperative outcome you can think of. There is, of course, the donor site morbidity to consider, but at present, this represents one of the best comprehensive assessments of these two competing approaches.

Achilles tendon: operative or not?

Failure patterns in ankle arthroplasty retrievals

With just 800 ankle arthroplasties a year undertaken in England and Wales, it is unsurprising that there is little evidence to support one implant design over another. In particular, the best design features are not clearly described and supported with clinical data, although inferences can be made from the difference in survivals of specific joint arthroplasties. The authors of this study from Hanover, New Hampshire (USA) have presented one of the few retrieval studies of ankle arthroplasty components, the results of which shed some light on the failure patterns of different implant designs.³ This paper revolves around retrieval analysis and laboratory analysis of 70 ankle components of seven different designs. Analysis was undertaken for wear and component damage, along with fixation analysis for metallic components and oxidation of polyethylene components. There were higher rates of loosening seen with fixed-bearing designs, which occurred in this series after a shorter interval. The presence of fatigue failure and cracking was related to the level of oxidation measured in the retrieved component. This, in turn, was associated with gamma sterilization of the polyethylene during its manufacture process. Some of this is self-evident and mirrors findings related to total knee arthroplasties. However, this is one of the first retrieval studies in this area and, with a sufficient range of implants and designs assessed to be able to draw some conclusions, it is a worthwhile read for anyone with more than a passing interest in ankle arthroplasty.

Approaches in calcaneal fractures

The debate surrounding calcaneal fractures now centres mostly on the complication rates. While significant complication rates have been reported, case series and smaller trials have suggested that there is the potential for improved functional outcomes with fixation. There is a reasonable presumption that if complication rates could be reduced, then fixation may offer a better outcome for some patients. This has resulted in renewed interest in alternative surgical approaches. Investigators in Daejeon (South Korea) set out to establish the potential benefits of the extended sinus tarsi approach (ESTA) over the extended lateral approach (ELA) as a method for treatment of displaced calcaneal fractures.⁴ Their retrospective study involved over 100 fractures in a retrospective comparative cohort study. The authors reported the results of 52 fractures treated with the ELA (46 patients) and 64 fractures treated with the ESTA (56 patients). Outcomes assessed were pain, patient-reported functional outcomes, satisfaction, and postoperative complications, which were investigated at the three-year timepoint. The authors also evaluated the pre- and postoperative radiographs, although one of the irrefutable outcomes from the United Kingdom Heel Fracture Trial (UKHeFT) is that accuracy of radiological reduction does not relate to clinical outcome to the extent that surgeons would like to think it does. The authors conclude that, from a radiological perspective, there was no difference in calcaneal width or Böhler angle at three years of follow-up. However, they do report a more accurate reduction in terms of posterior facet step-off in the ESTA group. The ELA group suffered more wound complications and nonunions, a finding that was mirrored by the improved Foot Function Index (FFI) and self-reported satisfaction rates in the ESTA group. In terms of surgical complications, the authors report four instances of superficial peroneal nerve injury in the ESTA group but none in the ELA group. Here at 360, we would agree with the authors’ conclusion that the ESTA now represents a well-recognized approach associated with fewer wound complications.

Just minimal or minimal and better?

A few years ago, both expert opinion and some early series suggested that minimally invasive first ray surgery could lead to lower rates of wound complications, albeit with the potential for inadvertent damage of structures, difficulties involved with achieving the same result, and increased cost required for the special instrumentation. For these reasons, minimally invasive first ray surgery has not made the leap to ‘standard care’ that many hoped it might. For some procedures, however, it certainly offers the potential of reduced soft-tissue complication, with the added benefit of a smaller scar. A surgical team from Newport (UK) have shared their results of minimally invasive dorsal cheilectomy in 98 patients with hallux rigidus, all of whom had failed conservative management.⁵ Patients were an average of 54 years old, and outcomes were assessed using the Manchester-Oxford Foot Questionnaire (MOxFQ) scores and visual analogue scale (VAS) for pain scores. There was no comparator group, so it is somewhat difficult to draw any inferences about relative effectiveness with other interventions. However, the results are a compelling addition to the evidence base for minimally invasive cheilectomy. The authors established that postoperative swelling was reduced in five weeks; there were two infected wounds and four neurological injuries (of which two were permanent). The VAS pain scores improved from 8 preoperatively to 3 following surgery, while the MOxFQ summary index score improved from 58.6 to 30.5 postoperatively. As would be expected with any series reporting on cheilectomy, there was a significant reoperation rate of 12%, which was accounted for by seven metatarsophalangeal joint fusions, four repeat cheilectomies, and one removal of loose bone. Overall, this series serves to establish the potential benefits of the minimally invasive approach to dorsal cheilectomy, although it cannot be used to justify one approach over another.

Are we giving the correct antibiotics for foot and ankle surgery?

Still a STAR after all these years?

The calcaneus: have we changed fracture practice?