Total ankle arthroplasty versus ankle arthrodesis: a comparative analysis of arc of movement and functional outcomes.

AIMS: Few reports compare the contribution of the talonavicular articulation to overall range of movement in the sagittal plane after total ankle arthroplasty (TAA) and tibiotalar arthrodesis. The purpose of this study was to assess changes in ROM and functional outcomes following tibiotalar arthrodesis and TAA. PATIENTS AND METHODS: Patients who underwent isolated tibiotalar arthrodesis or TAA with greater than two-year follow-up were enrolled in the study. Overall arc of movement and talonavicular movement in the sagittal plane were assessed with weight-bearing lateral maximum dorsiflexion and plantarflexion radiographs. All patients completed Short Form-12 version 2.0 questionnaires, visual analogue scale for pain (VAS) scores, and the Foot and Ankle Ability Measure (FAAM). RESULTS: In all, 41 patients who underwent TAA and 27 patients who underwent tibiotalar arthrodesis were enrolled in the study. The mean total arc of movement was 34.2° (17.0° to 59.1°) with an average contribution from the talonavicular joint of 10.5° (1.2° to 28.8°) in the TAA cohort. The average total arc of movement was 24.3° (6.9° to 44.3°) with a mean contribution from the talonavicular joint of 22.8° (5.6° to 41.4°) in the arthrodesis cohort. A statistically significant difference was detected for both total sagittal plane movement (p = 0.00025), and for talonavicular motion (p < 0.0001). A statistically significant lower VAS score (p = 0.0096) and higher FAAM (p = 0.01, p = 0.019, respectively) was also detected in the TAA group. CONCLUSION: TAA preserves more anatomical movement, has better pain relief and better patient-perceived post-operative function compared with patients undergoing fusion. The relative increase of talonavicular movement in fusion patients may play a role in the outcomes compared with TAA and may predispose these patients to degenerative changes over time. TAKE HOME MESSAGE: TAA preserves more anatomic sagittal plane motion and provides greater pain relief and better patient-perceived outcomes compared with ankle arthrodesis. Cite this article: Bone Joint J 2016;98-B:634-40.

MRI of injuries to the first interosseous cuneometatarsal (Lisfranc) ligament.

OBJECTIVE: The objective of this study was to assess the utility of MRI in diagnosing injury to the first interosseous cuneometatarsal (Lisfranc) ligament and to additionally determine the associated patterns of traumatic soft tissue and osseous injury. MATERIALS AND METHODS: Fifteen patients (16 feet) who were referred for MRI evaluation of the Lisfranc ligament, and had operative exploration or examination under anesthesia, were included for analysis. Standard non-contrast MRI foot imaging was performed in all cases. Evaluation of the following components was performed: the dorsal and plantar bundles of the Lisfranc ligament, the plantar tarsal metatarsal ligaments, soft tissue edema and fluid, and bone marrow edema and fractures. Surgical reports were regarded as the reference standard in all cases. RESULTS: Seven of 10 cases of grade 3 Lisfranc ligament injuries at surgery were correctly graded at MRI. No cases of surgically proven complete Lisfranc ligament tears (grade 3) were interpreted as normal at MRI. All Lisfranc ligament sprains (grade 2 or 3) at surgery were detected at MRI. Two of six cases reported as grade 1 injuries at MRI were normal at surgery. No cases of surgically proven normal or sprained Lisfranc ligaments were interpreted as grade 3 tears on MRI. Four of six of our cases of normal or sprained Lisfranc ligaments demonstrated fractures; while the minority of complete Lisfranc ligament tears (3/10) contained fractures. CONCLUSION: MRI is reasonably accurate at detecting traumatic injury to the Lisfranc ligament. However, in clinically suspected cases of traumatic Lisfranc ligament injury, true positive rate for sprain is low.

Biomechanical evaluation of the ability of casts and braces to immobilize the ankle and hindfoot.

We evaluated the ability of seven devices to immobilize a prosthetic ankle-foot complex against plantarflexion, dorsiflexion, inversion, and eversion forces: two casts (plaster of Paris and Fiberglas) and five removable braces (molded ankle/foot orthosis, composite boot brace, pneumatic boot walker, nonarticulating fracture boot, and ankle stirrup). Each device was applied to a prosthetic ankle-foot complex and evaluated on a test frame for resistance to sagittal motion and coronal torque. Results showed that casts offered significantly (P < or = 0.05) more resistance to motion in all directions tested than did the braces. The resistance offered by the devices tested depends on the conformity of the device to the shape of the foot in that plane and the material properties of the device. Braces offer the advantage of being easily removed and reapplied. Different braces offer specific advantages and disadvantages in different planes tested, and immobilization selection should be individualized based on this information.

Emerging technology: remote analysis of traumatic musculoskeletal radiographs transmitted by electronic mail.

OBJECTIVES: To determine whether remote analysis of radiographs via electronic mail (e-mail) had an impact on treatment decision-making. DESIGN: Prospective. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Twenty-five cases randomly selected from previous emergency room consultation. INTERVENTION: Textual descriptions obtained from emergency medicine physicians were compared with computer-digitized images of radiographs sent via e-mail and with the actual radiographs. Four board-certified orthopaedic surgeons reviewed all three forms of data to determine fracture diagnosis and treatment plans. MAIN OUTCOME ASSESSMENT: Diagnosis and treatment plans were obtained via written questionnaire after review of each group of data (textual, digitized image, and actual radiograph). Results were then compared across groups to determine whether digitized images were better than textual descriptions and equivalent to actual radiographs. RESULTS: Statistical analysis revealed a significant improvement in the frequency of correct diagnosis and treatment planning when digitized images were used (91 percent) compared with textual descriptions alone (48 percent) (p < 0.001). The difference in correct diagnosis and treatment plans between digitized images and actual radiographs was not statistically significant (p = 0.27). CONCLUSION: Digitized radiographs sent via e-mail can significantly improve accuracy of diagnosis and treatment compared with a simple verbal description.

Divot sign: a new observation in anterior impingement of the ankle.

Anterior impingement of the ankle results from osteophyte formation on the anterior edge of the distal tibia. Classically, subsequent degeneration results in an osteophyte forming on the anterior neck of the talus. This results in limited dorsiflexion and impingement seen in the ankles of athletes. Recent clinical observation in high performance soccer players has revealed a previously unrecognized pattern of a localized divot forming in the talar neck in place of the osteophyte. This accepts the tibial osteophyte during dorsiflexion, which is therefore not limited in these patients.

Effect of nicotine on the rate and strength of long bone fracture healing.

Empirical clinical observation suggests that cigarette smoking had an inhibitory effect on long bone fracture healing, but this has not been proven scientifically. Forty female New Zealand White rabbits had midshaft tibial osteotomies performed and plated. These were divided randomly into two groups receiving either systemic nicotine or saline (placebo). Lateral radiographs were taken at 4, 6, and 8 weeks that showed a 17.2% average difference in callus formation between the two groups and a significant lag in formation of cortical continuity in the nicotine group. The rabbits were sacrificed 8 weeks after fracture, and healing was compared biomechanically. Three (13%) fractures showed no clinical evidence of union in the nicotine group, whereas all fractures in the control group healed. Biomechanical testing showed the nicotine exposed bones to be 26% weaker in three-point bending than were those exposed to placebo.