Articular Cartilage of the Syndesmosis: Avoiding Iatrogenic Cartilage Injury During Syndesmotic Fixation

Background: The optimal surgical management of syndesmosis injuries consists of internal fixation between the distal fibula and tibia. Much of the available data on this joint details the anatomy of the syndesmotic ligaments. Little is published evaluating the distribution of articular cartilage of the syndesmosis, which is of importance to minimize the risk of iatrogenic damage during surgical treatment. The purpose of this study is to describe the articular cartilage of the syndesmosis. Methods: Twenty cadaveric ankles were dissected to identify the cartilage of the syndesmosis. Digital images of the articular cartilage were taken and measured using calibrated digital imaging software. Results: On the tibial side, distinct articular cartilage extending above the plafond was identified in 19/20 (95%) specimens. The tibial cartilage extended a mean of 6 ± 3 (range, 2-13) mm above the plafond. On the fibular side, 6/20 (30%) specimens demonstrated cartilage proximal to the talar facet, which extended a mean of 24 ± 4 (range, 20-31) mm above the tip of the fibula. The superior extent of the syndesmotic recess was a mean of 10 ± 3 (range, 5-17) mm in height. In all specimens, the syndesmosis cartilage did not extend more than 13 mm proximal to the tibial plafond and the syndesmotic recess did not extend more than 17 mm proximal to the tibial plafond. Conclusion: Syndesmosis fixation placed more than 13 mm proximal to the tibial plafond would have safely avoided the articular cartilage in all specimens and the synovial-lined syndesmotic recess in most. Clinical Relevance: This study details the articular anatomy of the distal tibiofibular joint and provides measurements that can guide implant placement during syndesmotic fixation to minimize the risk of iatrogenic cartilage damage.

Does the orientation of syndesmosis fixative device affect the immediate reduction of the distal tibiofibular joint?

Introduction Incongruent stabilization of the distal tibiofibular joint (syndesmosis) results in poorer long-term outcome in malleolar fractures. The aim was to analyze whether the orientation of the syndesmotic stabilization would affect the immediate reduction imaged in computed tomography (CT). Materials and methods The syndesmotic congruity in 114 ankle fractures with stabilization of the syndesmosis were retrospectively analyzed in the post-operative bilateral CT scans. The incisura device angle (IDA) was defined and correlated with the side-to-side difference of Leporjärvi clear-space (ΔLCS), anterior tibiofibular distance (ΔantTFD) and Nault talar dome angle (ΔNTDA) regardless of the stabilization technique and separately for suture button system and syndesmotic screw. Asymmetric reduction was defined as ΔLCS > 2 mm and |ΔantTFD|> 2 mm. Results Regardless of the stabilization technique, no correlation between the IDA and the ΔLCS (r = 0.069), the ΔantTFD (r = 0.019) nor the ΔNTDA (r = 0.177) could be observed. There were no differences between suture button system and syndesmotic screw. Asymmetrical reduction was detected in 46% of the cases, while sagittal asymmetry was most common. No association was found between the orientation of stabilization device and occurrence of asymmetrical reduction (p > 0.05). The results of suture button system and syndesmotic screw were comparable in this respect (p > 0.05). Conclusion Poor correlation between the orientation of the stabilization device and the immediate post-operative congruity of the syndesmosis could be shown. In contrast to current literature, this study did not show difference of suture button system over syndesmotic screw in this regard. Careful adjustment of the fibula in anteroposterior orientation should be given special attention.

Associations Between the Morphological Parameters of Proximal Tibiofibular Joint (PTFJ) and Changes in Tibiofemoral Joint Structures in Patients with Knee Osteoarthritis

BackgroundTo describe the longitudinal associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and joint structural changes in tibiofemoral compartments in patients with knee osteoarthritis (OA).MethodsThe participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. PTFJ morphological parameters were measured on coronal and sagittal MRI. The contacting area (S) of PTFJ, and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ) and coronal plane (posterior stress-bolstering area, Sυ) were assessed. Knee structural abnormalities, including cartilage defects, bone marrow lesions (BMLs) and cartilage volume, were evaluated at baseline and after 2 years. Log binominal regression models and linear regression models were used to assess the associations between PTFJ morphological parameters and osteoarthritic structural changes.ResultsIn the longitudinal analyses, the S (RR: 1.45) and Sτ (RR: 1.55) of PTFJ were significantly and positively associated with an increase in medial tibial (MT) cartilage defects. The Sτ (β: -0.07), Sυ (β: -0.07), and S (β: -0.06) of PTFJ were significantly and negatively associated with changes in MT cartilage volume. The Sτ (RR: 1.55) of PTFJ was positively associated with an increase in MT BMLs, and Sφ (RR: 0.35) was negatively associated with an increase in medial femoral BMLs. ConclusionsThis longitudinal study suggests that higher load-bearing area of PTFJ could be a risk factor for structural changes in medial tibiofemoral (MTF) compartment in knee OA. This may provide a theoretical support for proximal fibular osteotomy in the treatment of MTF OA.Trial registration: Clinicaltrials.gov Identifier: NCT01176344; Anzctr.org.au Identifier: ACTRN12610000495022Date of registration: 7 May 2010