The paper deals with the torques of external muscles acting on the upper ankle joint under weight-bearing conditions and their importance in diagnosing and treating the human foot. Experimental data ...were collected and calculations were performed. Based on the experiments with the biomechanical model of the foot and upper ankle joint, it was shown how the changes in the force arms of the external muscles of the foot under weight-bearing conditions, change the torque. The real values of muscle forces and torques of the external muscles of the foot were calculated. Taking into account the distance of the lines of muscle action from the axis of rotation of the upper ankle joint the rotational force of the muscles was calculated. The influence of changing the force arm on the rotational efficiency of the muscle balancing the moment of gravity was shown. Knowledge of muscle torque under weight-bearing conditions is crucial for correctly assessing foot biomechanics. It has been shown that torque (gravitational and muscular), not pure force, is crucial when assessing the rotational capacity of the analyzed joint. A change in the approach to diagnostics and treating paresis or weakness of extrinsic foot muscles was proposed through the manipulation of the distance of their action line from the axis of joint rotation.
Purpose
The modified Broström operation for chronic ankle instability has demonstrated good clinical results. Absence of ligamentous tissue is a risk factor for recurrence of ankle instability after ...surgery. This study evaluated the effect of quality of ligament tissue (anterior talofibular ligament, ATFL) on prognosis, in a cohort of patients with chronic ankle instability after the modified Broström operation.
Methods
This was a retrospective case series. Overall, 60 patients underwent the modified Broström operation for chronic ankle instability (mean follow-up, 30.1 range, 24–47 months). Presence of ATFL remnant was assessed on ultrasound, magnetic resonance imaging, and arthroscopy in all patients. Foot and ankle outcome score (FAOS) was used to evaluate functional outcomes. Clinical outcomes were compared by the condition of the ligament remnant. Association with other risk factors was evaluated using multiple linear regression analysis.
Results
ATFL was visible in 51/60 cases on ultrasound. Thirty, 22, and eight patients had thin or absent; normal thickness; and thick ATFL on magnetic resonance imaging, respectively. ATFL was visible in 15 patients on arthroscopy and nonvisible or not clear in 45. No significant differences occurred in FAOS with the presence of ATFL remnant on ultrasound, arthroscopy, and the grade of ATFL thickness on magnetic resonance imaging. No correlation was found between FAOS and the thickness of ATFL.
Conclusion
The results suggest that the modified Broström operation for patients with chronic ankle instability was good, regardless of the presence or absence of ATFL remnant.
Level of evidence
III, Retrospective cohort study.
Osteochondral lesions of the ankle are a more common source of ankle pain than previously recognized. Although the exact pathophysiology
of the condition has not been clearly established, it is ...likely that a variety of etiological factors play a role, with trauma,
typically from ankle sprains, being the most common. Technological advancements in ankle arthroscopy and radiologic imaging,
most importantly magnetic resonance imaging, have improved diagnostic capabilities for detecting osteochondral lesions of
the ankle. Moreover, these technologies have allowed for the development of more sophisticated classification systems that
may, in due course, direct specific future treatment strategies. Nonoperative treatment yields best results when employed
in select pediatric and adolescent patients with osteochondritis dissecans. However, operative treatment, which is dependent
on the size and site of the lesion, as well as the presence or absence of cartilage damage, is frequently warranted in both
children and adults with osteochondral lesions. Arthroscopic microdrilling, micropicking, and open procedures, such as osteochondral
autograft transfer system and matrix-induced autologous chondrocyte implantation, are frequently employed. The purpose of
this article is to review the history, etiology, and classification systems for osteochondral lesions of the ankle, as well
as to describe current approaches to diagnosis and management.
BACKGROUND:Treatment of end-stage ankle osteoarthritis remains challenging, especially in young patients. Initial reports have shown early benefits of joint distraction for the treatment of ankle ...osteoarthritis. We report the five to ten-year results of a previously described patient cohort following ankle distraction surgery.
METHODS:All thirty-six patients who had undergone ankle distraction surgery between December 2002 and October 2006 were contacted. Patients were evaluated by a clinical investigator and completed the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) surveys. Radiographs as well as computed tomography and magnetic resonance imaging scans of the ankles were obtained at the follow-up visits.
RESULTS:Twenty-nine patients (81%) were followed for a minimum of five years (mean and standard deviation, 8.3 ± 2.2 years). Sixteen (55%) of the twenty-nine patients still had the native ankle joint whereas thirteen patients (45%) had undergone either ankle arthrodesis or total ankle arthroplasty. Positive predictors of ankle survival included a better AOS score at two years (hazard ratio HR = 0.048, 95% confidence interval CI = 0.0028 to 0.84, p = 0.04), older age at surgery (HR = 0.91, 95% CI = 0.83 to 0.99, p = 0.04), and fixed distraction (HR = 0.094, 95% CI = 0.017 to 0.525, p < 0.01). Radiographs and advanced imaging revealed progression of ankle osteoarthritis at the time of final follow-up.
CONCLUSIONS:Ankle function following joint distraction declines over time. Patients should be well informed of the commitment that they must make during the treatment period as well as the long-term results after surgery.
LEVEL OF EVIDENCE:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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 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).
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.
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.
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.
Supramalleolar osteotomy is a joint-preserving surgical treatment for patients with asymmetric valgus or varus ankle arthritis. The primary goal of the procedure is to realign the spatial ...relationship between the talus and tibia and thereby normalize joint loading within the ankle. Procedures to balance the soft tissues, as well as hindfoot osteotomy and arthrodesis, may also be necessary. Clinical studies of supramalleolar osteotomy demonstrate that correction of the altered biomechanics associated with asymmetric arthritis improves functional outcomes.
Purpose
To evaluate the difference between T2 relaxation values of the subtalar cartilage in lateral ankle instability patients and healthy volunteers.
Materials and Methods
This institutional review ...board-approved study included 27 preoperative magnetic resonance imaging (MRI) examinations of 26 patients who underwent Broström operations. Data of previously enrolled healthy volunteers (12 volunteers, 13 MRIs) were used as controls. Two radiologists independently measured T2 values in eight posterior subtalar joint cartilage compartments: central calcaneus anterior (CCA) and posterior (CCP), central talus anterior (CTA) and posterior (CTP), lateral calcaneus anterior (LCA) and posterior (LCP), and lateral talus anterior (LTA) and posterior (LTP). Patient and control values were compared using linear regression analysis. Inter- and intraobserver agreement was calculated.
Results
Mean T2 values were significantly higher in the patient group in all measurements of subtalar joint cartilage compartments (
p
< 0.05) except that in LTP (
p
= 0.085) measured by reviewer 1. Both inter- and intraobserver agreements were excellent.
Conclusions
The T2 relaxation values of the subtalar cartilage were significantly higher in lateral ankle instability patients compared with those of controls.
Key Points
• Subtalar cartilage T2 values are increased in patients with lateral ankle instability.
• This trend was demonstrated regardless of the presence of talar dome cartilage lesions.
• Inter-and intraobserver agreements were excellent (intraclass coefficient range, 0.765-0.951) in subtalar cartilage T2 mapping.
BACKGROUND:We determined the preoperative and postoperative passing points of the mechanical axis of the lower limb at the level of the tibial plafond using a new method involving a full-length ...standing posteroanterior radiograph that includes the calcaneus (a hip-to-calcaneus radiograph) and correlated them to the clinical results after supramalleolar osteotomy for ankle osteoarthritis.
METHODS:We reviewed the hip-to-calcaneus radiographs of fifty lower limbs of forty-one patients treated for lower limb malalignment at our institution. The mechanical axis point of the ankle was the point at which the mechanical axis divides the coronal length of the plafond, expressed as a percentage. Four independent observers performed all measurements twice. Supramalleolar tibial osteotomy was performed in twenty-seven ankles (twenty-four patients) to treat moderate varus-type osteoarthritis of the ankle. The mean follow-up period was 2.8 years (range, two to 5.3 years). Clinical assessment was based on the American Orthopaedic Foot & Ankle Society (AOFAS) scale.
RESULTS:Interobserver and intraobserver reliability in identifying the mechanical ankle joint axis point were very high. The mean postoperative mechanical axis point was 50% (range, 13% to 70%) in ankles for which the preoperative point was ≤0%, whereas the mean postoperative point was 81% (range, 48% to 113%) in ankles for which the preoperative point was >0%. The mean change in AOFAS score was significantly less for patients with a preoperative point of ≤0% than for those with a preoperative point of >0% (p = 0.004). Improvement was significantly greater in ankles with a postoperative mechanical ankle joint axis point of ≥80% than in ankles with a postoperative mechanical ankle joint axis point of <60% (p = 0.030).
CONCLUSIONS:Traditional tibial correction resulted in great variation in the locations of the postoperative mechanical ankle joint axis point. In ankles with the preoperative point more medial than the tibial plafond, the point was insufficiently moved to the lateral side, and the clinical outcomes were less satisfactory.
LEVEL OF EVIDENCE:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Given the high volume of patient visits for foot and ankle complaints, developing a systematic approach to evaluation of foot and ankle pathology is important for orthopaedic providers. A thorough ...evaluation of weight-bearing radiographs is essential to differentiate acute and chronic injury from normal findings to dictate treatment. Radiographic changes and varying degrees of deformity can influence surgical considerations. The purpose of this article was to review and define radiographic measurements relevant to surgical decision making for common foot and ankle pathologies and treatment.
The ankle is the most frequently injured major joint in the body, and ankle sprains are frequently encountered in individuals playing football, basketball, and other team sports, in addition to ...occurring in the general population. Imaging plays a crucial role in the evaluation of ankle ligaments. Magnetic resonance imaging has been proven to provide excellent evaluation of ligaments around the ankle, with the ability to show associated intraarticular abnormalities, joint effusion, and bone marrow edema. Ultrasonography (US) performed with high-resolution broadband linear-array probes has become increasingly important in the assessment of ligaments around the ankle because it is low cost, fast, readily available, and free of ionizing radiation. US can provide a detailed depiction of normal anatomic structures and is effective for evaluating ligament integrity. In addition, US allows the performance of dynamic maneuvers, which may contribute to increased visibility of normal ligaments and improved detection of tears. In this article, the authors describe the US techniques for evaluation of the ankle and midfoot ligaments and include a brief review of the literature related to their basic anatomic structures and US of these structures. Short video clips showing dynamic maneuvers and dynamic real-time US of ankle and midfoot structures and their principal pathologic patterns are included as supplemental material. Use of a standardized imaging technique may help reduce the intrinsic operator dependence of US. Online supplemental material is available for this article.
PDF
