Ankle Traction During MRI of Talar Dome Osteochondral Lesions

Is the cadaveric model valid for examining orthopaedic manual therapy techniques? A cross-sectional comparative study in vivo and in vitro

BACKGROUND

Cadaveric models are sometimes used to test the effect of manual techniques. We have not found any studies comparing the effect of tibiotarsal joint distraction on cadaveric models versus live models for clinical use. The aim was to compare the effect on tibiotarsal joint distraction movement when applying three force magnitudes of tibiotarsal axial traction technique force between a cadaveric model and volunteers. In addition, to compare the magnitude of force applied between the cadaveric model and volunteers. Finally, to assess the reliability of applying the same magnitude of force in three magnitudes of tibiotarsal axial traction force.

METHODS

A cross-sectional comparative study was conducted. Sixty ankle joints were in open-packed position and three magnitudes of tibiotarsal axial traction technique force were applied. Tibiotarsal joint distraction movement was measured with ultrasound.

FINDINGS

No differences were found in applied force or tibiotarsal joint distraction between volunteers and cadavers in each magnitude of force (p > 0.05). The application of the technique showed moderate reliability for detecting low forces in both models. For medium and high force, it showed good reliability in the in vitro model and excellent reliability in the live model.

INTERPRETATION

The amount of distraction produced in the tibiotarsal joint was similar in volunteers and cadavers. The cadaveric model is a valid model for testing and investigating orthopaedic manual therapy techniques. The force applied was similar in the two models. Medium and high force detection showed good reliability, while low force showed moderate.

Relevance of Tibial Fixation during Tibiotarsal Joint Traction: Descriptive Cross-Sectional Study

Background: The effect of tibial fixation on the movement of the talus during the tibiotarsal axial traction technique (TATT) is unknown. The aim was to evaluate the effect on the tibiotarsus when applying three different intensities of TATT force with or without tibial fixation in healthy subjects, and to assess the reliability of detecting the different forces applied. Also, the discomfort generated during the technique would be analysed. Methods: A cross-sectional study was conducted in thirty lower limbs. Three magnitudes of TATT force in an open-packed position were applied in tibial fixation and non-fixation conditions. The axial traction movement was measured by ultrasound, and the magnitudes of the force applied during low-medium and high TATT force were recorded in both conditions. Patients were asked about the level of discomfort perceived during the technique. Results: The most significant distance increase (mm) was observed in the tibial fixation condition at all magnitudes of the TATT (F = 102.693, p < 0.001). The discomfort sensation (numeric rating scale, "NRS") was higher in the non-fixation condition (p > 0.05). The application of the technique showed good reliability (>0.75 ICC) for the detection of the applied force. Conclusions: The TATT in the tibial fixation condition produced more significant axial movement of the talus (mm) relative to the tibia than the non-tibial fixation condition did. The detection of the magnitudes of movement showed good reliability (ICC: 0.75 to 0.92). The technique was well tolerated at all force magnitudes, with the tibial fixation condition being the most tolerable.

Osteochondral Lesions of the Ankle and Foot

Osteochondral lesions (OCLs) in the ankle are more common than OCLs of the foot, but both share a similar imaging appearance. Knowledge of the various imaging modalities, as well as available surgical techniques, is important for radiologists. We discuss radiographs, ultrasonography, computed tomography, single-photon emission computed tomography/computed tomography, and magnetic resonance imaging to evaluate OCLs. In addition, various surgical techniques used to treat OCLs-debridement, retrograde drilling, microfracture, micronized cartilage-augmented microfracture, autografts, and allografts-are described with an emphasis on postoperative appearance following these techniques.

Talar Dome Osteochondral Lesions: Pre- and Postoperative Imaging

We suggest a similar approach to evaluating osteochondral lesions of the talar dome both pre- and postoperatively. This review addresses the etiology, natural history, and treatment of talar dome osteochondral lesions with an emphasis on imaging appearances. High-resolution magnetic resonance imaging, ideally combining a small field-of-view surface coil with ankle traction, optimizes visibility of most of the clinically relevant features both pre- and postoperatively.

Osteochondral Lesions of the Talus May Cause the Vacuum Phenomenon in the Ankle Joint

The few reports available on the vacuum phenomenon in the ankle joint refer to osteoarthritic and traumatic lesions. We present the first case concomitant with an osteochondral lesion of the talus. This case report presents computed tomographic images of the ankle. We speculate that the osteochondral lesion of the talus was the most likely cause of the vacuum phenomenon.

Weight-Bearing CT Scan After Tibial Pilon Fracture Demonstrates Significant Early Joint-Space Narrowing

BACKGROUND

Posttraumatic osteoarthritis (PTOA) is a common and early sequela of tibial pilon fractures resulting in substantial long-term disability. New approaches are needed to objectively and reliably quantify early disease progression in order to critically assess the impact of interventions aimed at preventing or mitigating PTOA. Weight-bearing computed tomography (WBCT) scans provide a means for measuring joint space while the ankle is in a loaded, functional position. We assessed the interrater and intrarater reliability of a standardized, regional method to quantify joint-space loss following tibial pilon fracture compared with the uninjured contralateral ankle.

METHODS

We prospectively enrolled 20 patients with intra-articular tibial pilon fractures that were surgically treated at 1 of 2 level-I trauma centers. Six months after injury, bilateral ankle WBCT scans were obtained. Joint space was measured by 4 reviewers at 9 discrete regions of the tibiotalar articulation on sagittal images. Measurements were repeated by reviewers 2 weeks later. To characterize the measurement method, interrater correlation coefficient estimates and test-retest reproducibility were calculated.

RESULTS

The mean tibiotalar joint space was 21% less in the injured ankles compared with the contralateral uninjured ankles (p < 0.0001). The middle-lateral and middle-central regions of the joint demonstrated the greatest decrease in joint space between injured and uninured ankles. The interrater correlation coefficient of the measurement technique was 0.88, and the test-retest reproducibility was 0.80, indicating good reliability and reproducibility of the method.

CONCLUSIONS

We developed a simple, standardized, and reliable technique to quantify tibiotalar joint space following tibial pilon fracture on WBCT. Significant loss of joint space is seen 6 months after the injury. This tool can be used to longitudinally quantify loss of joint space following pilon fracture and assess the impact of interventions to reduce PTOA.

Accessibility to Talar Dome in Neutral Position, Dorsiflexion, or Noninvasive Distraction in Posterior Ankle Arthroscopy

BACKGROUND

Osteochondral lesions of the talus are frequent pathologies of the ankle joint. Especially through arthroscopy, the treatment is kept as minimally invasive as possible. However, there are some drawbacks as to the reachability because of the high congruency of the ankle joint. Here, either noninvasive distraction or maximal dorsiflexion may be an option for better access to the lesion. The purpose of this study was to evaluate maximal dorsiflexion compared to neutral position or noninvasive distraction of the ankle joint in the arthroscopic reachability of the talar dome. The hypothesis of this study was that maximal dorsiflexion would allow for greater accessibility of the talar dome compared to neutral position or noninvasive distraction of the joint.

METHODS

Twenty matched pairs (n=40) of anatomical ankle specimens were used. The effects of neutral position, maximal dorsiflexion, and noninvasive distraction of the ankle joint on arthroscopic accessibility of the ankle joint were tested. After disarticulation of the talus, reach was measured and compared between the 3 positions.

RESULTS

In neutral position, 13.7±1.2 mm of the talar dome was reached laterally and 14.0±1.0 mm medially. In maximal dorsiflexion, the distance was 19.0±1.1mm laterally and 19.8±1.4 mm medially, and in noninvasive distraction it was 16.1±1.5 mm laterally and 15.7±1.0 mm medially. The statistical comparison showed a significantly better reach in dorsiflexion laterally (P = .003) and medially (P = .026).

CONCLUSION

Accessibility of the talar dome in maximal dorsiflexion was superior to that in neutral position or noninvasive distraction.

CLINICAL RELEVANCE

Results of this study may allow for better planning in arthroscopic treatment of osteochondral lesions of the talus.

Evaluation of Articular Cartilage Injury Using Computed Tomography With Axial Traction in the Ankle Joint

BACKGROUND

Although chondral or osteochondral injuries are usually assessed by magnetic resonance imaging, its accuracy can be low, presumably related to the relatively thin cartilage layer and the close apposition of the cartilage of the talus and tibial plafond. We hypothesized that axial traction could provide a contrast between the articular cartilage and joint cavity, and it enabled the simultaneous evaluation of cartilage and subchondral bone. The purpose of this study was to assess the feasibility of using computed tomography (CT) imaging with axial traction for the diagnosis of articular cartilage injuries.

METHODS

Chondral lesions in 18 ankles were evaluated by CT with axial traction using a tensioning device and ankle strap for enlargement of the joint space of the ankle. CT was done in 3-mm slices and programmed for gray scale, and then CT images were allocated colors to make it easier to evaluate the cartilage layer. The International Cartilage Repair Society (ICRS) grades on CT were compared with those on arthroscopic findings.

RESULTS

The respective sensitivity and specificity of CT imaging with traction using ICRS grading were 74.4%, and 96.3%. The level of agreement of the ICRS grading between CT images and arthroscopic findings was moderate (kappa coefficient, 0.547). Adding axial traction to CT increased the delineation of the cartilage surface, including chondral thinning, chondral defect, and cartilage separation.

CONCLUSIONS

CT with axial traction produced acceptable levels of sensitivity and specificity for the evaluation of articular cartilage injuries, in addition to the assessment of subchondral bone.

LEVEL OF EVIDENCE

Level III, comparative case series.