Understanding the foot's functional anatomy in physiological and pathological conditions: the calcaneopedal unit concept.

BACKGROUND: A thorough review of the available orthopaedic literature shows significant controversies, inconsistencies and sparse data regarding the terminology used to describe foot deformities. This lack of consensus on terminology creates confusion in professional discussions of foot anatomy, pathoanatomy and treatment of deformities. The controversies apply to joint movements as well as static relationships between the bones. DESCRIPTION: The calcaneopedal unit (CPU) is a specific anatomical and physiological entity, represented by the entire foot excepted the talus. The calcaneus, midfoot and forefoot are solidly bound by three strong ligaments that create a unit that articulates with the talus. The movement of the CPU is complex, as it rotates under the talus, around the axis of Henke that coincides with the talo-calcaneal ligament of Farabeuf.This calcaneopedal unit is deformable. It is compared with a twisted plate, able to adapt to many physiological situations in standing position, in order to acheive a plantigrade position.Moreover, the calcaneopedal unit and the talo-tibiofibular complex are interdependent; rotation of the latter produces morphologic modifications inside the former and vice versa. PURPOSE: This paper is a review article of this concept and of its physiopathological applications.

Delayed presentation of popliteal artery injury during Ilizarov limb lengthening.

Major vascular injury can result during use of the Ilizarov technique for lower extremity limb lengthening. Vascular reconstruction may be accomplished while leaving the external fixation ring in place. Continued distraction is made possible by leaving sufficient redundancy in the vascular graft.

Management of clubfoot deformity in amyoplasia.

Forty-one clubfeet in 22 patients with amyoplasia were studied retrospectively at a mean duration after surgery of 118 months (range, 45-253). The clubfeet were managed by a regimen including initial stretching casts, posteromedial release, and postoperative splinting at night. The mean age at the time of surgery was 7.3 months. Correction of deformity without recurrence was achieved in 11 (27%). Recurrent deformity was corrected by serial casting in eight feet and required secondary operative procedures in 20 feet. In the feet without recurrence of deformity, the duration of splinting at night after surgery was significantly longer than in those with recurrence (p < 0.05). At follow-up, 39 (95%) feet were plantigrade and were considered satisfactory. Our findings suggest that most clubfeet in amyoplasia can be effectively corrected by posteromedial release and that the recurrence of deformity can be reduced by splinting at night and often corrected by serial cast treatment.

Orthopaedic manifestations of invasive group A streptococcal infections complicating primary varicella.

The incidence of invasive group A streptococcal (GAS) infections in primary varicella appears to be increasing. GAS infections complicating varicella range from cellulitis, abscess, and septic arthritis to life-threatening necrotizing fasciitis and pyomyositis in association with GAS toxic shock syndrome (TSS). Four patients admitted in 1 year to the Children's Hospital and Medical Center in Seattle, whose care included evaluation and treatment by the Orthopaedic service, are presented to illustrate this spectrum. Three had a delay in diagnosis, including discharge from previous emergency department visits. One patient with polyarticular septic arthritis was treated with diagnostic aspiration and intravenous antibiotics. The remainder required urgent surgical debridement for treatment of deep infection. Patients with necrotizing fasciitis or pyomyositis had life-threatening complications of TSS, including hypotension, adult respiratory distress syndrome (ARDS), coagulopathy, and acute renal failure. These patients required aggressive fluid resuscitation and prolonged intensive care unit support. Diagnostic imaging studies were obtained in one patient with necrotizing pyomyositis but may have served only to delay definitive treatment. Recognition of the potential for secondary GAS infections and a high index of suspicion for the presence of necrotizing soft-tissue infection are essential in the evaluation of any child with fever and localized extremity pain with varicella.

Calcaneal lengthening for valgus deformity of the hindfoot. Results in children who had severe, symptomatic flatfoot and skewfoot.

Thirty-one severe, symptomatic valgus deformities of the hindfoot in twenty children who had flatfoot (twenty-five feet) or skewfoot (six feet) were corrected with a modification of the calcaneal lengthening osteotomy described by Evans. Despite prolonged non-operative treatment, all patients had pain, a callus, ulceration, or a combination of these signs and symptoms under the head of the plantar flexed talus; they could not tolerate a brace, and shoe wear was excessive. Twenty-six of the deformities were secondary to an underlying neuromuscular disorder. The calcaneal lengthening was combined with an opening-wedge osteotomy of the medial cuneiform to correct the deformities of both the hindfoot and the forefoot in the patients who had a skewfoot. Other concurrent osseous and soft-tissue procedures were frequently performed in the flatfeet and skewfeet to correct adjacent deformities or to balance the muscle forces. Allograft bone was used in twenty-four feet and autogenous bone, in seven. The patients ranged in age from four years and seven months to sixteen years at the time of the operation. The duration of follow-up ranged from two years to three years and seven months after the operation. Satisfactory clinical and radiographic correction of all components of the deformity of the hindfoot was achieved in all but the two most severely deformed feet. These two feet had sufficient correction to eliminate the symptoms despite a small persistent callus under the head of the talus. The pain and callus were eliminated in all of the other feet, the patients were able to tolerate a brace, and shoe wear was improved. Subtalar motion was preserved in all feet except for the four that had had a limited joint arthrodesis performed previously or simultaneously for pre-existing degenerative osteoarthrosis. Calcaneal lengthening is effective for the correction of severe, intractably symptomatic valgus deformities of the hindfoot in children. My patients had resolution of the signs and symptoms associated with the deformity while avoiding the need for an arthrodesis and the many short and long-term complications associated with it.

Fracture of the cuboid in children. A source of leg symptoms.

We report eight cases of fracture of the cuboid in seven children under four years of age, collected during a two-year period. There was no history of trauma in five of the patients. This fracture is rarely diagnosed and has probably been under-reported. Small children are poor historians and difficult to examine, and early radiographs may be normal or have only subtle abnormalities. Cuboid fracture should be considered in the differential diagnosis of limping toddlers, and a bone scan may be needed to confirm the diagnosis earlier than radiography. These fractures heal completely, without sequelae. Treatment in a short-leg walking cast is recommended, primarily for reasons of comfort.

Effect of calcaneal lengthening on relationships among the hindfoot, midfoot, and forefoot.

To better understand the bony component of pes planus and the means by which the Evans calcaneal lengthening corrects them, we studied the standing radiographs of seven adult patients who had undergone calcaneal lengthening to treat symptomatic pes planus. Weightbearing AP and lateral views done preoperatively and postoperatively were used for the study. For each set of films, the following parameters were measured: on the lateral view; overall length of the calcaneus, lateral talometatarsal angle, lateral talocalcaneal angle, and the calcaneal pitch angle; and on the dorsoplantar view, the talometatarsal and talocalcaneal angle. In addition, the relative coverage of the talus by the navicular was described by an angular measurement based on the relationship of the center of the talus to the center of the navicular. The average improvements in lateral talocalcaneal angle (a reflection of hindfoot valgus) was 6.4 degrees when the long axis of the calcaneus was used and 6.8 degrees when the inferior surface of the calcaneous was used for the measurement. The lateral talometatarsal angle improved an average 11.3 degrees (from an average of 19.7 degrees to 8.4 degrees). The dorsoplantar talometatarsal angle (a measure of forefoot adduction/abduction) improved 15.8 degrees (preoperative average 26.8 degrees, postoperative average 11 degrees). The calcaneal pitch angle improved an average 10.8 degrees (preoperative average 3.2 degrees, postoperative average 14 degrees). The relationship between the talus and navicular was defined by an angular measurement based on the center of each articular surface before and after correction using this measurement. An average improvement of 26 degrees occurred in the alignment of these two articular surfaces.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory outcome of children with myelomeningocele: effect of lower-extremity muscle strength.

The relationship between patterns of strength and mobility was studied in 291 children with myelomeningocele, graded as community ambulators, partial (household) ambulators and nonambulators. Iliopsoas strength was found to be the best predictor of ambulation, with the quadriceps, anterior tibialis and glutei also contributing significantly. Grade 0 to 3 iliopsoas strength was always associated with partial or complete reliance on a wheelchair. No patient with grade 4 to 5 iliopsoas and quadriceps function relied completely on wheelchairs and the majority were community ambulators. Grade 4 to 5 gluteal and anterior tibialis function was associated with community ambulation, without aids or braces. Deterioration in mobility was most common in those with strong iliopsoas/quadriceps and grade 0 to 3 gluteus medius, and was not age-related.

Displaced intra-articular fractures of the tarsal navicular.

Between 1980 and 1987, twenty-one patients who had a displaced fracture of the body of the tarsal navicular were treated with open reduction and internal fixation. A classification system was devised on the basis of the direction of the fracture line, the pattern of disruption of the surrounding joints, and the direction of displacement of the foot. In a Type-1 injury, the fracture line is in the coronal plane and there is no angulation of the fore part of the foot. In a Type-2 fracture, the primary fracture line is dorsal-lateral to plantar-medial, and the major fragment and the fore part of the foot are displaced medially. In a Type-3 injury, there is a comminuted fracture in the sagittal plane of the body of the tarsal navicular, and the fore part of the foot is laterally displaced. Satisfactory reduction, which was defined as restoration of more than 60 per cent of the joint surface in the anteroposterior and lateral planes, was achieved in all Type-1 injuries, 67 per cent of the Type-2 fractures, and 50 per cent of the Type-3 fractures. Radiographic evidence of healing was seen at an average of 8.5 weeks after injury. At an average follow-up of forty-four months (range, twelve to 106 months), a good result was noted in fourteen patients (67 per cent); a fair result, in four (19 per cent); and a poor result, in three (14 per cent). Both the type of fracture and the accuracy of the operative reduction directly correlated with the final clinical outcome.

Pitfalls in diagnosis: the hip.

The hip joint is unique anatomically, physiologically, and developmentally. Because of these features, diagnosis of pathologic conditions is more difficult than for most joints. Because delay in diagnosis and treatment may result in crippling osteoarthritis, it is imperative that diagnostic pitfalls be avoided.

Medial femoral torsion and osteoarthritis.

We investigated the hypothesis that medial femoral torsion is a predisposing factor to osteoarthritis of the hip. Anteversion was measured by biplane radiography in 44 hips (32 patients) with idiopathic osteoarthritis of the hip and a control group of 98 normal hips (49 adults). The mean and range of anteversion measures were similar in both groups. The mean was 22 degrees for osteoarthritic hips (range 3 degrees-49 degrees) and 19 degrees for normal controls (range -2 degrees-49 degrees). This difference was not significant. This study disagrees with others that propose an association between increased anterversion and osteoarthritis of the hip. Prophylactic operative correction of femoral torsion for osteoarthritis is not recommended.

Management of hip dislocations in children with arthrogryposis.

From a review of 131 children with arthrogryposis, we studied 18 patients with hip dislocations. Fourteen patients (10 unilateral, four bilateral) were treated by open reduction. Mean age at surgery was 9.7 months, and follow-up ranged from 9 to 245 months. Range of motion of patients treated by open reduction following the medial approach was greater than in those treated by anterolateral incision and greater than in bilateral cases treated by closed reduction. Acetabular development was satisfactory following the medial approach and there were no re-dislocations, but one hip developed avascular necrosis.