1. Occult fracture-subluxation of the midtarsal joint is described and illustrated by a typical case. 2. Comments are made on the mechanism of injury, diagnostic features and treatment

Injuries involving the midtarsal joint, which are frequently misdiagnosed, have been studied to clarify the mechanism, classification and treatment. The necessity for routine antero-posterior, lateral and oblique radiographs is emphasised. Seventy-one injuries have been classified according to the direction of the deforming force : medial, longitudinal compression, lateral, plantar and crush types are described. Included in the medial and lateral types is a hitherto undescribed tarsal rotation or " swivel" injury. The mechanism whereby longitudinal compression causes fractures of the body of the navicular is described, and two varieties having different prognoses are defined : one due to purely longitudinal compression and the other due to longitudinal compression with a medial component. The results of treatment have been assessed clinically and radiologically. Reduction, open if necessary, with internal fixation, is recommended for displaced fractures : primary arthrodesis is not indicated. For severe persistent symptoms from medial and longitudinal force injuries triple arthrodesis is recommended, and from lateral force injuries, calcaneo-cuboid arthrodesis

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

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

Charcot osteoarthropathy of the foot is a chronic and progressive disease of bone and joint associated with a risk of amputation. The main problems encountered in this process are osteopenia, fragmentation of the bones of the foot and ankle, joint subluxation or even dislocation, ulceration of the skin and the development of deep sepsis. We report our experience of a series of 20 patients with Charcot osteoarthropathy of the foot and ankle treated with an Ilizarov external fixator. The mean age of the group was 30 years (21 to 50). Diabetes mellitus was the underlying cause in 18 patients. Five had chronic ulcers involving the foot and ankle. Each patient had an open lengthening of the tendo Achillis with excision of all necrotic and loose bone from the ankle, subtalar and midtarsal joints when needed. The resulting defect was packed with corticocancellous bone graft harvested from the iliac crest and an Ilizarov external fixator was applied. Arthrodesis was achieved after a mean of 18 weeks (15 to 20), with healing of the skin ulcers. Pin track infection was not uncommon, but no frame had to be removed before the arthrodesis was sound. Every patient was able to resume wearing regular shoes after a mean of 26.5 weeks (20 to 45)

A method of triple arthrodesis is described which involves inlay of the subtalar and midtarsal joints. It is applicable to the undeformed and valgus foot as is encountered in poliomyelitis, spasmodic flat foot, cerebral palsy and spina bifida. The operation was successful in controlling deformity and pain. The only significant complication was failure of fusion of the midtarsal joint which occurred in three of eighty-five feet (3-5%)

1) Supination and pronation are the only material tarsal movements; other terms describe their hypothetical components only. 2) The subtalar and talo-navicular joints form a single joint functionally, which may be called the peritalar joint. 3) Peritalar movement comprises a wide range of supination and pronation of the foot about an axis which passes from the tuberosity of the calcaneum upwards, forwards and slightly medially to the neck of the talus. 4) Midtarsal movement comprises a narrow range of supination and pronation of the foot about an axis similar to that of peritalar movement. 5) Tile peritalar and midtarsal joints are thus oblique hinge joints

Among 449 patients with leprosy, 40 had clinical and radiographic evidence of neuroarthropathy in 50 feet. These changes were classified into four types according to the joints first involved by major lesions: ankle (25 feet), midtarsal (15 feet), tarsometatarsal (7 feet) and subtalar (3 feet). The progression of joint destruction was different in each type, but despite the severe destructive changes seen in radiographs, the patients had relatively few complaints. The muscles innervated by the peroneal nerve were severely paralysed in ankle and midtarsal types and it seems that, over a long term, repeated trauma and/or abnormal stress may lead to these types of neuroarthropathy. Neuropathy was less severe in the tarsometatarsal type of joint degeneration; the pathogenesis in this type seemed to be mainly direct trauma to the forefoot

We report four cases of fracture of the cuboid treated by open reduction, bone grafting where necessary and internal fixation. We recommend this treatment where there is appreciable displacement of one or more of the articular surfaces. The preliminary results were better than those previously reported for conservative treatment or for later midtarsal fusion

Twenty-four patients who attended the Edinburgh Limb Fitting Centre with 26 healed amputations through the middle part of the foot have been traced. The results in patients with Chopart's ablation through the midtarsal joints and in those with amputation through or near the tarsometatarsal region, were surprisingly good. Three of the patients who also had a contralateral Syme's stump reported that the shortened foot was superior in almost all respcts

A retrospective study involving thirty-six patients with thirty-seven ankle fusions was undertaken to assess the rate of fusion, the subjective and objective results, the residual subtalar and midtarsal movement, and the functional disability. Fusion occurred in thirty-one ankles (84 per cent). Twenty-four patients were reviewed, on average 7.5 years after fusion, and eighteen had good or excellent results; only four had been unable to return to their previous employment. The conclusion is that fusion is still a good treatment for the painful post-traumatic arthritis ankle, the resulting functional disability being minimal

The results of 62 ankle arthrodeses, mostly performed for osteoarthritis, have been reviewed; of these, 39 were examined clinically and radiographically after an average follow-up period of seven years. Compression arthrodesis was associated with the highest incidence of complications, and an anterior sliding graft gave the most satisfactory results. Very few patients required modification of their footwear; most could walk independently with a slight limp and were able to return to their pre-operative work. However, after operation, the ability to run and to participate in vigorous sporting activities was limited. Complications included wound infection, non-union, and some change in midtarsal mobility, but excellent pain relief was reported by all patients

We have reviewed the results of 19 ankle arthrodeses in 18 patients by a new technique of posterior internal compression. Sixteen of the ankles fused at a mean time of 14 weeks and the other three after reoperation. Complications included one case each of infection, Sudeck's atrophy and non-fatal pulmonary embolism. Clinical assessment using Mazur's ankle score showed excellent or good results in nine ankles and three painfree ankles in patients who were wheelchair-bound for other reasons. The mean position of fusion was in 1.7 degrees equinus and 0.8 degrees varus, and the mean range of midtarsal movements was 15.8 degrees. Twelve patients showed radiographic signs of talonavicular or subtalar osteoarthritis

Patients with spina bifida cystica commonly have significant disability from a combination of valgus deformity of the ankle and subtalar joints with lateral tibial torsion and plano-abduction deformity of the foot. These deformities can be corrected by a single procedure which combines a supramalleolar tibial osteotomy with a lateral inlay triple fusion. This procedure was carried out on 20 feet in 15 patients and the results were reviewed after an average of three years (range 18 months to 7 years). In 75 per cent of feet the combination of deformities was fully corrected, ulcers and callosities were eliminated in 95 per cent, the use of calipers minimised in 95 per cent, and in all patients the problem of shoe-wrecking was reduced. Complications included recurrent valgus deformity, delayed union of the tibial osteotomy and failure of midtarsal fusion

We studied the development of ball-and-socket deformity of the ankle by arthrography and radiography in 14 ankles of ten patients with congenital longitudinal deficiency of the fibula accompanied by various anomalies. The mean follow-up was for 18 years 10 months. In three ankles in infants less than one year old the lateral and medial sides of the ankle were already slightly round. In another seven ankles the ball-and-socket appearance developed before the age of five years. This was thought to be due to osseous coalition which limits eversion and inversion. In another four ankles in children who were over the age of one year at the initial examination, the deformity was demonstrated by arthrography and radiography at their first examination. Ball-and-socket deformity accompanied by tarsal coalition is an acquired deformity secondary to limitation of movement of the subtalar and midtarsal joints. It has completely developed by about five years of age

Isolated dislocations of the navicular are rare injuries; we present our experience of six cases in which the navicular was dislocated without fracture. All patients had complex injuries, with considerable disruption of the midfoot. Five patients had open reduction and stabilisation with Kirschner wires. One developed subluxation and deformity of the midfoot because of inadequate stabilisation of the lateral column, and there was one patient with ischaemic necrosis. We believe that the navicular cannot dislocate in isolation because of the rigid bony supports around it; there has to be significant disruption of both longitudinal columns of the foot. Most commonly, an abduction/pronation injury causes a midtarsal dislocation, and on spontaneous reduction the navicular may dislocate medially. This mechanism is similar to a perilunate dislocation. Stabilisation of both medial and lateral columns of the foot may sometimes be essential for isolated dislocations. In spite of our low incidence of ischaemic necrosis, there is always a likelihood of this complication

1. Fifty-eight major injuries in the region of the talus were reviewed regarding treatment, incidence of complications and long-term results. 2. The prognosis for simple fractures of the head, neck or body was good, as was that for dislocations of the midtarsal and peritalar joints. 3. The prognosis for fracture-dislocations of the neck and body was better than has been frequently reported. It was related to the degree of initial trauma. A good result occurs only if accurate reduction is effected and maintained. Fixation with a Kirschner wire is a useful method of maintaining the reduction after unstable fracture-dislocations. 4. Avascular necrosis occurred only in the more severe injuries and its incidence was related to the degree of initial displacement. The late results were better than have been previously described. The condition is best treated conservatively by protection from weight-bearing until revascularisation is well advanced. 5. A case with an unusual pattern of fracture of the neck of the talus is described following a plantar-flexion inversion injury

A subjective, objective and radiographic study of 21 patients with comminuted calcaneal fractures showing severe involvement of the subtalar joint is reported. The average follow-up was 14.6 years (range 8 to 29 years). Only patients with unilateral closed fractures and no associated injuries to either lower limb were admitted to the study. All were treated by early active mobilisation of the ankle, and the subtalar and the midtarsal joints. Seventy-six per cent of the patients achieved a good result with minor symptoms which did not interfere with their occupation or leisure requirements. Although two-thirds of the patients reached a point of maximal recovery at two to three years, 24% continued to improve for six years. None of the patients experienced any deterioration after this time. Neither the degree of clinical stiffness nor the degeneration of the subtalar joint, assessed radiographically, correlated with the severity of symptoms or functional disability. The role of the soft tissues in the aetiology of residual symptoms is discussed

Aims

Patients with a deformity of the hindfoot present a particular challenge when performing total knee arthroplasty (TKA). The literature contains little information about the relationship between TKA and hindfoot alignment. This systematic review aimed to determine from both clinical and radiological studies whether TKA would alter a preoperative hindfoot deformity and whether the outcome of TKA is affected by the presence of a postoperative hindfoot deformity.

Aims

To assess the effect of age on clinical outcome and revision rates in patients who underwent total ankle arthroplasty (TAA) for end-stage ankle osteoarthritis (OA).