Introduction: Pain is the key symptom of patients suffering of osteochondral lesion (OCL) of the ankle. However, its tissue origin and the pain inducing and modulating mechanisms remain controversial. Cartilage is aneural and unlikely causing pain. Contrary soft and bone tissue show rich nociceptive innervations. Routine radiographic imaging of OCL fails to visualize the pain inducing structure. Recent studies demonstrated the capability of planar scintigraphy and SPECT for localizing painful joints in degenerative joints conditions. However, a limited spatial resolution of bone scans compromises an accurate anatomical localization of an uptake. Single photon emission computed tomography – computed tomography (SPECT-CT) is a new hybrid imaging technique allowing perfect overlay of functional and anatomical images. In OCL, SPECT-CT identifies the exact location of an OCL and determines the spatial extent of pathological bone remodeling. We conducted a study to evaluate the correlation between pathological uptake within an OCL and pain experienced by patients.

Methods: 15 patients (7 female, 8 male; mean age 39, range 20–61 years) were assessed for unilateral OCL of the talus (13 joints) or distal tibia (2 joints). Radiological imaging of the foot and ankle consisted of plain radiographs, MRI and SPECT-CT. Clinical examination included range of motion (ROM), AOFAS Ankle-Hind-foot Scale, and pain status measured by the visual analogue scale (VAS). On completion of radiological and clinical assessment, patients were referred to the interventional radiology department for a diagnostic ankle injection. CTguided ankle joint injection with local anesthetics and iodine contrast medium was performed. Exact location of the deposit was documented.

VAS score was assessed immediately post-infiltration and compared to the pre-interventional VAS score. Pain relief was defined as a reduction of VAS score of more than 50% of the pre-intervention score immediately after infiltration.

The study was approved by the institutional review board and written informed patient consent was obtained. The study was carried out in accordance with the World Medical Association Declaration of Helsinki.

Results: All infiltrations were technically successful. Pre-interventional VAS score was 5.3 (range 2 - 10; SD 2.33). Post-interventional VAS score was 1.1 (range 2 – 4; SD 1.45). This difference was statistically significant (p < 0.01).

Discussion: The results of our study show a highly significant correlation between pain in OCL and pathological uptake seen on SPECT-CT, indicating bone as a major contributor to pain in this disease. Hybrid SPECT-CT technique is a new and powerful approach to diagnosis and staging of osteochondral lesions and provides important data for adequate treatment.

Background: While several studies in the last years tried to identify clinical limitations of patients suffering from end-stage ankle osteoarthritis (OA), very few attempted to assess foot and ankle function in a more objective biomechanical way, especially using dynamic pedobarography. The aim of the study was therefore to explore plantar pressure distribution characteristics in a large cohort of posttraumatic end-stage ankle OA.

Method: 120 patients (female, 54; male, 66; 120 cases) suffering from posttraumatic end-stage ankle OA were included. The clinical examination consisted of assessment of the AOFAS hindfoot score, a pain score, the range of motion (ROM) for ankle dorsiflexion and plantar flexion, and the body mass index (BMI, kg/m2). Radiological parameters included the radiological tibiotalar alignment and the radiological ankle OA grading. Plantar pressure distribution parameters were assessed using dynamic pedobarography.

Results: Intra-individual comparison between the affected and the opposite, asymptomatic ankle revealed significant differences for several parameters: maximum pressure force and contact area were decreased in the whole OA foot, such was maximum peak pressure in the hindfoot and toes area. No correlations could be found between clinical parameters, such as AOFAS hindfoot score, VAS for pain, and ROM, and the pedobarographic data. However, there was a positive correlation between dorsiflexion and the pedobarographic parameters for the hindfoot area.

Conclusion: In conclusion, posttraumatic end-stage ankle OA leads to significant alterations in plantar pressure distribution. These might be interpreted as an attempt of the patient to reduce the load on the painful ankle. Other explanations might be bony deformity and ankle malalignment as a consequence of either the initial trauma or of the degenerative process itself, pain related disuse atrophy of surrounding muscles, and scarred soft tissue.

Introduction: Posttraumatic osteoarthritis of the ankle joint usually occurs secondary to an intraarticular fracture of the weight bearing ankle joint. The question whether also recurrent ankle sprain and /or chronic instability alone can cause this entity, is, however, still a question to debate. The aim of this retrospective study was, therefore, to analyse the history and findings of a consecutive series of patients that were treated for post-traumatic end-stage osteoarthrosis of the ankle.

Methods: The complete database (including physical exam, standard radiographs, patient questionnaire and AOFAS hindfoot score) of all patients was analysed.

Results: Out of 268 patients (females, 135 patients; males, 133) 221 (82.5%) had had a fracture (Fx) and 47 (17.5%) suffered from chronic ankle instability with recurrent sprains (but did not have a fracture). The latter group could be subdivided into 29 (10.8%) patients with recurrent sprains (RS) and 10 (6.7%) patients with only a single sprain (SS). The mean (range) delay between primary trauma and surgical treatment for endstage osteoarthritis was 21.1 (1–58) months for Fx, 37.07 (1–61) months for RS and 22.5 (5–48) months for SS.

Conclusion: Obviously, not only fractures, but also severe sprains and /or chronic instability play an important role as a cause of end stage osteaorthrosis of the ankle joint. The obtained results suggest that a single severe sprain (dislocation) can cause similar articular damages to an intraarticular fracture, as the time to develop osteoarthrosis does not differ. This is in contrast to the current opinion that ankle sprain, in most instances, does not result in symptomatic articular degeneration.