Background

Whereas arthroscopic arthrodesis of the ankle is commonplace and of the subtalar joint is established, reports of arthroscopic talo-navicular fusion are a rarity.

Aims

The Chopart joint complex is a joint between the midfoot and hindfoot. The static and dynamic support system of the joint is critical for maintaining the medial longitudinal arch of the foot. Any dysfunction leads to progressive collapsing flatfoot deformity (PCFD). Often, the tibialis posterior is the primary cause; however, contrary views have also been expressed. The present investigation intends to explore the comprehensive anatomy of the support system of the Chopart joint complex to gain insight into the cause of PCFD.

Background. The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to classify the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction. Methods. We included 20 cavovarus feet from adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, 14 males). Patients included had flexible deformities, with no previous surgery. Previous work established majority of rotational deformity in cavovarus feet occurs at the talonavicular joint, which is often reduced during surgery. Using specialised software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using data from normal feet as a guide, the talonavicular joint of the cavovarus feet was digitally reduced to a ‘normal’ position. Models of the corrected position were exported and geometrically analysed using Blender 3.6 to identify anatomical trends. Results. We identified 3 types of cavovarus forefoot morphotypes. Type 1 was seen in 13 cases (65%) and was defined as a foot where only the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular correction. Type 2 was seen in 4 cases (20%) and was defined as a foot where the second and first metatarsals were progressively plantarflexed, with no significant adduction. Type 3 was seen in 3 cases (15%) and was defined as a foot where the metatarsals were still adducted after talonavicular de-rotation. Conclusion. We classify 3 forefoot morphotypes in cavovarus feet. It is important to recognise and anticipate the residual forefoot deformities after hindfoot correction as different treatment strategies may be required for different morphotypes to achieve balanced correction

Objective. The objective of this study was to evaluate the rotation and translation of each joint in the hindfoot and compare the load response in healthy feet with that in stage II posterior tibial tendon dysfunction (PTTD) flatfoot by analysing the reconstructive three-dimensional (3D) computed tomography (CT) image data during simulated weight-bearing. . Methods. CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot were taken first in a non-weight-bearing condition, followed by a simulated full-body weight-bearing condition. The images of the hindfoot bones were reconstructed into 3D models. The ‘twice registration’ method in three planes was used to calculate the position of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint. Results. From non- to full-body-weight-bearing condition, the difference in the talus position relative to the calcaneus in the talocalcaneal joint was 0.6° more dorsiflexed (p = 0.032), 1.4° more everted (p = 0.026), 0.9 mm more anterior (p = 0.031) and 1.0 mm more proximal (p = 0.004) in stage II PTTD flatfoot compared with that in a healthy foot. The navicular position difference relative to the talus in the talonavicular joint was 3° more everted (p = 0.012), 1.3 mm more lateral (p = 0.024), 0.8 mm more anterior (p = 0.037) and 2.1 mm more proximal (p = 0.017). The cuboid position difference relative to the calcaneus in the calcaneocuboid joint did not change significantly in rotation and translation (all p ≥ 0.08). . Conclusion. Referring to a previous study regarding both the cadaveric foot and the live foot, joint instability occurred in the hindfoot in simulated weight-bearing condition in patients with stage II PTTD flatfoot. The method used in this study might be applied to clinical analysis of the aetiology and evolution of PTTD flatfoot, and may inform biomechanical analyses of the effects of foot surgery in the future. Cite this article: Bone Joint Res 2013;2:255–63

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

The standard treatment of arthrosis of the ankle joint is arthrodesis while new prosthesis leed to good clinical results. Currently there is much controversial discussion, and knowledge of the fundamentals of biomechanics is becoming ever more important. Ten macroscopically and roentgenographically normal foot specimens were tested comparing tibio-talar arthodesis vs. nativ situation on a kinematic gait simulator. The stance- phase of normal walking gait was simulated from heel-contact to toe-off. Ground reaction forces were simulated by a tilting angle- and force-controlled translation stage upon which a pressure measuring platform was mounted. Force was applied to the tendons of the foot flexor and extensor muscle groups by cables attached to an additional set of six force-controlled hydraulic cylinders. Tibial rotation was produced by an electrical servo motor. The change after arthrodesis was a varying degree of relocation of average force and maximum pressure from the lateral onto the medial column of the foot; the increase force on talonavicular joint and decrease on calcaneocuboid joint is statistically significant. The average force increased from native 66.7N to 80.8N upon arthrodesis in the talonavicular joint and decreased in the calcaneocuboid joint from 71.9N to 58.5N. Peak pressure increased from 3728kPa to 4552kPa in talonavicular joint and decreased in calcaneocuboid joint from 3809kPa to 3627kPa. After arthrodesis, we measured inconsistent changes in Chopart joint. On some feet, the changes in stress were slight, but on majority, relocation of force and peak pressure was significant. The result was a change in the function of Chopart joint with increased extension load on talonavicular joint at time of highest joint load during push-off. These in vitro observations explain the clinical observations that have followed ankle arthrodesis. For one, there are reports on tibiotalar arthrodesis patients who are largely mobile and free of complaints, which correlates with the observation that not all preparations indicate a clear relocation of force and intraarticular peak pressure onto the talonavicular joint. In these cases, the ability of strong muscular plantar flexion could explain a good functional result. In contrast, and in addition to subtalar joint degeneration, arthroses in the talonavicular joint have been frequently observed following tibiotalar arthrodeses. The relocation of both force and intraarticular peak pressure onto the medial column of the foot in the majority of preparations explain the degeneration on the extensor side of the joint with osteophyte formation impressively

Background. Total ankle replacements (TARs) are becoming increasingly more common in the treatment of end stage ankle arthritis. As a consequence, more patients are presenting with the complex situation of the failing TAR. The aim of this study was to present our case series of isolated ankle fusions post failed TAR using a spinal cage construct and anterior plating technique. Methods. A retrospective review of prospectively collected data was performed for 6 patients that had isolated ankle fusions performed for failed TAR. These were performed by a single surgeon (IW) between March 2012 and October 2014. The procedure was performed using a Spinal Cage construct and grafting in the joint defect and anterior plating. Our primary outcome measure was clinical and radiographic union at 1 year. Union was defined as clinical union and no evidence of radiographic hardware loosening or persistent joint lucent line at 1 year. Results. The mean follow-up was 37.3 months (SD 13.2). Union was achieved in 5 of the 6 patients (83%). One patient had a non-union that required revision fusion incorporating the talonavicular joint that successfully went on to unite across both joints. Another patient had radiographic features of non-union but was clinically united and asymptomatic and one required revision surgery for a bulky symptomatic lateral malleolus with fused ankle joint. Conclusion. The failing TAR presents a complex clinical situation. After removal of the implant there is often a large defect which if compressed leads to a leg length discrepancy and if filled with augment can increase the risk of non-union. Multiple methods have been described for revision, with many advocating fusion of both the ankle joint and subtalar joint. We present our case series using a spinal cage and anterior plating that allows preservation of the subtalar joint and a high rate of union

Background. The only existing classification of Müller-Weiss Disease (MWD), based solely on Méary's angle, serves neither as guide for prognosis nor treatment. This accounts for lack of gold standard in its management. Methods. Navicular compression, medial extrusion, Kite's angle and metatarsal lengths were measured on all radiographs of 95 feet with MWD. Joints involved, presence and location of navicular fracture were recorded. Results. We identified three distinct groups. Group 1 comprises 11 “early-onset” MWD feet, aged 9 to 29 years. These had the greatest compression and medial extrusion, and lowest Kite's angles. All except 1 were index minus and had a lateral navicular fracture. None has required surgery to date. Only 1 has moderate talonavicular joint (TNJ) degeneration. Group 2 comprises 23 “Müller-Weissoid” feet with radiologically normal navicular in their fifties and developing MWD, on average, 4.5 years later. These had the lowest compression and extrusion, and highest Kite's angles. None had complete fracture. All had TNJ arthritis, with early changes at lateral naviculocuneiform joint (NCJ) in 43%. Group 3 “late-onset” MWD, presenting in the sixth decade, is subdivided into 3 sub-groups. Only TNJ is involved in group 3A (16). Group 3B denotes affection of TNJ more than NCJ (20). In group 3C “reverse Müller-Weiss disease”, which affects NCJ more than TNJ (25), second metatarsal overlength is highest of all groups. No difference in age, compression, extrusion and Kite's angle exists among the 3 subgroups. No fracture occurred in group 3A compared to 65% and 32% in groups 3B and 3C, respectively. Conclusions. With a need to compare like-for-like pathology, the proposed classification provides a common platform for reporting outcomes of different treatment modalities, operative or nonoperative. We theorize pathogenetic pathways in the different groups and propose systematic surgical approaches for each category

Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial approach and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 10 cadaveric specimens. Distraction of the joint was performed as standard for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches. Disarticulation was performed and the marked surface area was quantified using a digital Microscribe allowing a three dimensional virtual model of the articular surfaces to be assessed. This study will provide quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint. These data may provide support for the use of the dorsal approach for talonavicular arthrodesis

Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 11 cadaveric specimens (10 fresh frozen, 1 embalmed). Distraction of the joint was performed as used intraoperatively for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches using a previous reported technique3. Disarticulation was performed and the marked surface area was quantified using an immersion digital microscribe, allowing a three dimensional virtual model of the articular surfaces to be assessed. The median percentage of accessible total talonavicular articular surface for the medial and dorsal approaches was 71% and 92% respectively. This difference was significant (Wilcoxon Signed Ranks Test, p<0.001). This study provides quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint. These data support for the use of the dorsal approach for talonavicular arthrodesis

Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 11 cadaveric specimens (10 fresh frozen, 1 embalmed). Distraction of the joint was performed as used intraoperatively for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches using a previous reported technique. Disarticulation was performed and the marked surface area was quantified using an immersion digital microscribe, allowing a three dimensional virtual model of the articular surfaces to be assessed. The median percentage of accessible total talonavicular articular surface for the medial and dorsal approaches was 71% and 92% respectively. This difference was significant (Wilcoxon Signed Ranks Test, p< 0.001). This study provides quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint. These data support for the use of the dorsal approach for talonavicular arthrodesis

Aims. Fractures of the navicular can occur in isolation but, owing to the intimate anatomical and biomechanical relationships, are often associated with other injuries to the neighbouring bones and joints in the foot. As a result, they can lead to long-term morbidity and poor function. Our aim in this study was to identify patterns of injury in a new classification system of traumatic fractures of the navicular, with consideration being given to the commonly associated injuries to the midfoot. Patients and Methods. We undertook a retrospective review of 285 consecutive patients presenting over an eight- year period with a fracture of the navicular. Five common patterns of injury were identified and classified according to the radiological features. Type 1 fractures are dorsal avulsion injuries related to the capsule of the talonavicular joint. Type 2 fractures are isolated avulsion injuries to the tuberosity of the navicular. Type 3 fractures are a variant of tarsometatarsal fracture/dislocations creating instability of the medial ray. Type 4 fractures involve the body of the navicular with no associated injury to the lateral column and type 5 fractures occur in conjunction with disruption of the midtarsal joint with crushing of the medial or lateral, or both, columns of the foot. Results. In order to test the reliability and reproducibility of this new classification, a cohort of 30 patients with a fracture of the navicular were classified by six independent assessors at two separate times, six months apart. Interobserver reliability and intraobserver reproducibility both had substantial agreement, with kappa values of 0.80 and 0.72, respectively. Conclusion. We propose a logical, all-inclusive, and mutually exclusive classification system for fractures of the navicular that gives associated injuries involving the lateral column due consideration. We have shown that this system is reliable and reproducible and have described the rationale for the subsequent treatment of each type. Cite this article: Bone Joint J 2018;100-B:176–82

Background. Current literature of definition, classification and outcomes of fractures of talar body remains controversial. Our primary purpose is to present an unusual combination of fractures of talar body with pantalar involvement / dislocation / extension as a basis for modification of Müller AO / OTA Classification. Methods. We include four consecutive patients, who sustained talar body fractures with pantalar subluxation/dislocation /extension. These unusual injury patterns lead us to reconsider Müller AO / OTA Classification in the light of another widely used talar fracture classification, Hawkins Classification of fractures of neck of talus and subsequent modification by Canale and Kelly. Results. Müller AO / OTA Classification comprises CI – Ankle joint involvement, C2 – Subtalar joint involvement, C3 – Ankle and subtalar joint involvement. We propose Modification of Müller AO / OTA. Classification. C1 – Absolutely undisplaced fracture; C2 – Ankle and Subtalar joint involvement: subluxation; C3 – Ankle and subtalar joint involvement: subluxation with comminution; C4 – Ankle, subtalar and talonavicular joint involvement. Conclusions. Our modification redefines Müller AO / OTA Classification, extends and fills the void in the classification by inclusion of C4, draws attention to stability of talonavicular joint and reflects increasing severity of injury in fractures of talar body

In this study we evaluated the results of midtarsal release and open reduction for the treatment of children with convex congenital foot (CCF) (vertical talus) and compared them with the published results of peritalar release. Between 1977 and 2009, a total of 22 children (31 feet) underwent this procedure. In 15 children (48%) the CCF was isolated and in the remainder it was not (seven with arthrogryposis, two with spinal dysraphism, one with a polymalformative syndrome and six with an undefined neurological disorder). Pre-operatively, the mean tibiotalar angle was 150.2° (106° to 175°) and the mean calcaneal pitch angle was -19.3° (-72° to 4°). The procedure included talonavicular and calcaneocuboid joint capsulotomies, lengthening of tendons of tibialis anterior and the extensors of the toes, allowing reduction of the midtarsal joints. Lengthening of the Achilles tendon was necessary in 23 feet (74%). The mean follow-up was 11 years (2 to 21). The results, as assessed by the Adelaar score, were good in 24 feet (77.4%), fair in six (19.3%) and poor in one foot (3.3%), with no difference between those with isolated CCF and those without. The mean American Orthopaedic Foot and Ankle Society midfoot score was 89.9 (54 to 100) and 77.8 (36 to 93) for those with isolated CCF and those without, respectively. At the final follow-up, the mean tibiotalar (120°; 90 to 152) and calcaneal pitch angles (4°; -13 to 22) had improved significantly (p < 0.0001). Dislocation of the talonavicular and calcaneocuboid joints was completely reduced in 22 (70.9%) and 29 (93.6%) of feet, respectively. Three children (five feet) underwent further surgery at a mean of 8.5 years post-operatively, three with pes planovalgus and two in whom the deformity had been undercorrected. No child developed avascular necrosis of the talus. Midtarsal joint release and open reduction is a satisfactory procedure, which may provide better results than peritalar release. Complications include the development of pes planovalgus and persistent dorsal subluxation of the talonavicular joint. Cite this article: Bone Joint J 2014;96-B:837–44

We describe a retrospective review of the clinical and radiological parameters of 32 feet in 30 patients (10 men and 20 women) who underwent correction for malalignment of the hindfoot with a modified double arthrodesis through a medial approach. The mean follow-up was 21 months (13 to 37). Fusion was achieved in all feet at a mean of 13 weeks (6 to 30). Apart from the calcaneal pitch angle, all angular measurements improved significantly after surgery. Primary wound healing occurred without complications. The isolated medial approach to the subtalar and talonavicular joints allows good visualisation which facilitated the reduction and positioning of the joints. It was also associated with fewer problems with wound healing than the standard lateral approach

We investigated 60 patients (89 feet) with a mean age of 64 years (61 to 67) treated for congenital clubfoot deformity, using standardised weight-bearing radiographs of both feet and ankles together with a functional evaluation. Talocalcaneal and talonavicular relationships were measured and the degree of osteo-arthritic change in the ankle and talonavicular joints was assessed. The functional results were evaluated using a modified Laaveg-Ponseti score. The talocalcaneal (TC) angles in the clubfeet were significantly lower in both anteroposterior (AP) and lateral projections than in the unaffected feet (p < 0.001 for both views). There was significant medial subluxation of the navicular in the clubfeet compared with the unaffected feet (p < 0.001). Severe osteoarthritis in the ankle joint was seen in seven feet (8%) and in the talonavicular joint in 11 feet (12%). The functional result was excellent or good (≥ 80 points) in 29 patients (48%), and fair or poor (< 80 points) in 31 patients (52%). Patients who had undergone few (0 to 1) surgical procedures had better functional outcomes than those who had undergone two or more procedures (p < 0.001). There was a significant correlation between the functional result and the degree of medial subluxation of the navicular (p < 0.001, r. 2 . = 0.164), the talocalcaneal angle on AP projection (p < 0.02, r2 = 0.025) and extent of osteoarthritis in the ankle joint (p < 0.001). We conclude that poor functional outcome in patients with congenital clubfoot occurs more frequently in those with medial displacement of the navicular, osteoarthritis of the talonavicular and ankle joints, and a low talocalcaneal angle on the AP projection, and in patients who have undergone two or more surgical procedures. However, the ankle joint in these patients appeared relatively resistant to the development of osteoarthritis

The goal of clubfoot management, regardless of the method applied, is still to improve function and form as close as possible to normal values. Since the final outcome of any therapy will only become evident at the end of growth, long-term follow-up studies are necessary to evaluate the results and methods. The aim of this study was to evaluate long-term results of corrective surgery for clubfoot deformity in a selected group of patients. Other congenital or acquired abnormalities like neuromuscular disease, arthrogryposis or others were excluded in order to identify the factors associated with the success or failure of the treatment. A retrospective clinical and radiological study of 64 patients with 104 treated feet with a follow-up of 8 to 35 years (mean: 19.2 years) is presented. All of the patients were operated on by Scheel′s technique. In this technique the Achilles tendon was lengthened and combined with a dorsal arthrolysis. In some cases medial structures such as the tibialis posterior, long-toe flexors tendon sheaths and the medial ligaments of the talonavicular joint were released. A calcaneal traction was applied for four weeks and a plaster cast for six weeks. The patients were grouped according to the duration of follow-up (< 10, 10–20 and > 20 years) and the results were compared. Clinical evaluation followed the criteria according to the McKay Score, a score of 180 from which points for sequela (either morphologic or functional) are subtracted. There was an inverse relationship between the functional rating score and the length of follow-up. Acceptable results decrease over time as the patient approaches skeletal maturity. In the group with a follow-up of > 20 years, only 5% were rated as good, 34% as satisfactory, 28% as poor and 33 % as failure. Radiographic evaluation of the last group showed marked deformities of the talus and navicular bones, as well as advanced osteoarthritis. The degree of bone deformity of the talus (flat-top-talus) and navicular seems to depend on the degree of persistent residual joint subluxation after surgery and contribute to the development of secondary osteoarthritis of the ankle and subtalar joint over time. Considering the goal of treatment is to restore form and function, assessment and approach of all the components of the individual deformity is required. A complete subtalar release to realign the calcaneus to an externally rotated position is followed by a reduction of the talonavicular joint. To achieve full reduction, release of the calcaneocuboid joint is necessary because it is linked with the talonavicular joint. Preliminary results of 89 congenital clubfeet treated with a complete subtalar release with an average follow- up of five years show 12.4% excellent, 41.6% good and 39.3% satisfactory according to the McKay-Score. The results of this series underlines the importance of careful and complete derotation and anatomic realignment of the talocalcaneonavicular joint complex in order to have a lifelong functional foot with the least amount of deformity and disability. The results of any treatment for clubfoot deformity should be judged after skeletal maturity, making a follow-up of at least 20 years necessary

Introduction:. In a consecutive series of 71 arthroscopic subtalar arthrodeses performed between 2004 and 2011, 14 also involved arthroscopic decortication of the talonavicular joint (double arthrodesis) and 4 the subtalar, talonavicular and calcaneocuboid joints (triple arthrodeses). Methods:. We examined complications, union rates in all 18 patients and clinical outcomes in 16 for whom this was the sole procedure. Results:. Mean age was 62 (45–78). Two talonavicular joints failed to unite and a third patient suffered a diabetic Charcot midfoot neuro-arthropathy. These patients' outcomes were classified as poor. Two patients underwent planned major ankle or midfoot surgery in addition to arthroscopic double arthrodeses. These joints united but these patients were not included in the clinical review to avoid confounding outcomes. Mean follow-up for the remaining 13 patients was 4.4 (1.75–7.5) years. There were no immediate perioperative complications. All 4 patients with triple fusions united with good or excellent outcomes. The nine patients receiving double arthrodesis united with 8 good or excellent outcomes. The remaining patient reported good deformity correction and stability but disappointing pain relief, (classification poor). Conclusions:. Double and triple arthrodeses remain valid salvage options for painful arthrosis and severe deformity. Preservation of the calcaneocuboid joint permits a relative lateral column lengthening when correcting planovalgus deformity. Arthroscopic surgery offers preservation and protection of soft tissues and reduces wound tension. The sinus tarsi approach permits good visualisation and decortication of the triple joints and rotatory correction of deformity. This technique is not appropriate when there is extensive bone loss requiring block bone grafting. Early complications are reduced and late complications such as non-union and arthrosis of adjacent joints seem similar to those reported in studies on open arthrodeses

The contributions made by metatarsus primus varus, medial subluxation of the navicular, and angulation of the neck of the talus to the residual deformity in treated club feet were assessed from radiographs. Their relation to the appearance of the feet, to the age of the patient, to the results of operations, and to the age at the time of the first operation were investigated. Lateral rotation of the ankle and flattening of the talus were also studied. Medial subluxation of the navicular was found to be the most important factor influencing both the appearance of the feet and the lateral rotation of the ankle. Relocation of the talonavicular joint correlated with the success of operative treatment; and the timing of the primary operation determined the degree of relocation which could be achieved. Metatarsus primus varus and angulation of the talus were of little importance. Increased emphasis is given to the need for early relocation of the talonavicular joint

To evaluate the mechanism of dislocation of the navicular in complex foot trauma; we hypothesize this is similar to lunate/perilunate dislocations. Our experience with 6 cases of total dislocation of navicular without fracture, and an analysis of 7 similar cases reported world-wide was used as the basis for this hypothesis. Radiographs of our patients and the published cases were analyzed in detail, and associated injuries/instablilities were assessed. The position of the dislocated navicular and the mechanism of trauma was considered and correlated, and this hypothesis was propounded. When the navicular dislocates without fracture, it most frequently comes to lie medially, with superior or inferior displacement, depending upon the foot position at injury. It is hypothesized that the forefoot first dislocates laterally (perhaps transiently) at the naviculocunieform joint by an abduction injury; in all cases we recorded significant lateral injury (either cuboid fracture, or lateral midfoot dislocation). The relocating forefoot subsequently pushes the unstable navicular from the talonavicular joint, and depending upon the residual attachments of soft tissues, this bone comes to lie at different places medially. This is a similar mechanism to the lunate dislocation in the wrist, where the relocating carpus push the lunate volarly. Our clinical experience with these complex injuries has shown that the whole foot is extremely unstable. For reduction, the talonavicular joint has to be reduced first, and then the rest of the forefoot easily reduces on to the navicular. An understanding of injury mechanics allows us to primarily stabilize both the columns of the foot, and subsequent subluxation and associated residual pain are avoided. Pure navicular dislocations are not isolated injuries, but are complex midfoot instabilities, and are similar to perilunate injuries of the wrist