Aims

This systematic review aimed to summarize the full range of complications reported following ankle arthroscopy and the frequency at which they occur.

Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options.

Cite this article: Bone Joint J 2021;103-B(5):822–827.

The Bologna–Oxford (BOX) total ankle replacement (TAR) was developed with the aim of achieving satisfactory pain-free movement of the ankle. To date, only one single multicentre study has reported its clinical results. The aim of this study was to conduct an independent review of its mid-term results.

We retrospectively reviewed a total of 60 prospectively followed patients in whom 62 BOX TARs had been implanted between 2004 and 2008. We used the American Orthopedic Foot and Ankle Society (AOFAS) score to assess the clinical results. Standardised radiographs taken at the time of final follow-up were analysed by two observers. The overall survival was 91.9% at a mean follow-up of 42.5 months (24 to 71). The mean AOFAS score had improved from 35.1 points (sd 16.6; 4 to 73) pre-operatively to 78.0 (sd 10.7; 57 to 100) at final follow-up (p < 0.01). Tibial radiolucencies < 2 mm in width were seen around 16 TARs. Talar radiolucencies < 2 mm were seen around four TARs. A total of 47 patients (78.3%) were very satisfied or satisfied with the outcome. Five patients required revision for functional limitation or continuing pain.

Our study describes the clinical outcome of total ankle replacement (TAR) performed in patients with moderate to severe varus deformity. Between September 2004 and September 2007, 23 ankles with a varus deformity ≥ 10° and 22 with neutral alignment received a TAR. Following specific algorithms according to joint congruency, the varus ankles were managed by various additional procedures simultaneously with TAR.

After a mean follow-up of 27 months (12 to 47), the varus ankles improved significantly in all clinical measures (p < 0.0001 for visual analogue scale and American Orthopaedic Foot and Ankle Society score, p = 0.001 for range of movement). No significant differences were found between the varus and neutral groups regarding the clinical (p = 0.766 for visual analogue scale, p = 0.502 for American Orthopaedic Foot and Ankle Society score, p = 0.773 for range of movement) and radiological outcome (p = 0.339 for heterotopic ossification, p = 0.544 for medial cortical reaction, p = 0.128 for posterior focal osteolysis). Failure of the TAR with conversion to an arthrodesis occurred in one case in each group.

The clinical outcome of TAR performed in ankles with pre-operative varus alignment ≥ 10° is comparable with that of neutrally aligned ankles when appropriate additional procedures to correct the deformity are carried out simultaneously with TAR.

We performed a retrospective study to assess the long-term outcome of non-augmented anatomical direct repair of the lateral ankle ligaments, as originally described by Duquennoy et al, for the treatment of chronic lateral instability of the ankle. This procedure aims to restore stability by the re-insertion and tightening of the original talofibular and calcaneofibular ligaments without division of the ligament. We examined the outcome in terms of the post-operative quality of life, the function of the joint and the development of osteoarthritis.

Between 1985 and 2002, 23 patients (11 males, 12 females) with a mean age of 32 years (15 to 58) who had undergone this procedure completed the Short-Form 36 assessment of quality of life and the Olerud and Molander Ankle score for the subjective evaluation of symptoms. Clinical re-evaluation, including examination of the ankle and the completion of the American Orthopaedic Foot and Ankle Society questionnaire was performed on 21 patients after a mean follow-up of 13 years (3 to 22.2). At the final follow-up radiographs of both ankles were taken to assess the development of osteoarthritis.

The mean total Short-Form 36 and Olerud and Molander Ankle scores in 23 patients at final follow-up were 79.6 points (37 to 100) and 81.6 points (40 to 100), respectively. The mean total post-operative American Orthopaedic Foot and Ankle Society score in 21 patients was 89.7 points (72 to 100). We found a significant post-operative reduction in talar tilt and anterior drawer sign (chi-squared test, p < 0.001). The functional outcome of the procedure was excellent in ten patients (48%), good in seven (33%) and fair in four (19%). The results in terms of ankle function and stability did not deteriorate with time and there was little restriction in movement.

This procedure is simple and effective with a very low rate of complications.

A cavovarus foot deformity was simulated in cadaver specimens by inserting metallic wedges of 15° and 30° dorsally into the first tarsometatarsal joint. Sensors in the ankle joint recorded static tibiotalar pressure distribution at physiological load.

The peak pressure increased significantly from neutral alignment to the 30° cavus deformity, and the centre of force migrated medially. The anterior migration of the centre of force was significant for both the 15° (repeated measures analysis of variance (ANOVA), p = 0.021) and the 30° (repeated measures ANOVA, p = 0.007) cavus deformity. Differences in ligament laxity did not influence the peak pressure.

These findings support the hypothesis that the cavovarus foot deformity causes an increase in anteromedial ankle joint pressure leading to anteromedial arthrosis in the long term, even in the absence of lateral hindfoot instability.

Chronic ankle instability after ligamentous injuries has been attributed to loss of proprioception, but there has been no previous study of the mechanoreceptors in human ligaments at this joint. We have examined the ligaments from five cadaver ankles for mechanoreceptors and classified them into the four types described by Wyke and Freeman in their study of feline ligaments. Type-II receptors, thought to provide the sensation of the beginning of joint motion, and type-III receptors, thought to be activated at the extremes of movement, were the most common. Our findings provide some neuroanatomical data to validate further research into the use of proprioceptive training after ligamentous injuries about the ankle

We have treated 45 patients (47 ankles) for chronic lateral instability by a new reconstructive procedure. The operation includes lateral shift of the entire lateral capsule-ligament complex and proximal advancement of the talocalcaneal ligament and the inferior extensor retinaculum. We reviewed 39 patients (39 ankles) at a mean of 4.6 years (2 to 7) after operation. There were 29 men and 10 women with an average age of 27 years (19 to 43); 11 of them were competitive college-level athletes and 28 were recreational athletes. The functional rating was excellent in 26 patients, good in 8, fair in 3 and poor in 2. Thirty-six patients (92%) were satisfied with the result and 34 (9 of 11 college-level athletes and 25 of 28 recreational athletes) have been able to return to their preinjury level of sport. At the last review, there had been only three episodes of recurrent ankle instability, all in recreational athletes; none had required further surgery. The unsatisfactory results were associated with pre-existing degenerative changes in the ankle.