PubMed Health⌕ Search

Biomedical subjects

B J Sangeorzan

Publications and source records attributed to B J Sangeorzan.

At least 19 recordsLinked to original sources

An equinus deformity of the ankle accounts for only a small amount of the increased forefoot plantar pressure in patients with diabetes.

Patients with diabetes mellitus may develop plantar flexion contractures (equinus) which may increase forefoot pressure during walking. In order to determine the relationship between equinus and forefoot pressure, we measured forefoot pressure during walking in 27 adult diabetics with a mean age of 66.3 years (sd 7.4) and a mean duration of the condition of 13.4 years (sd 12.6) using an Emed mat. Maximum dorsiflexion of the ankle was determined using a custom device which an examiner used to apply a dorsiflexing torque of 10 Nm (sd 1) for five seconds. Simple linear regression showed that the relationship between equinus and peak forefoot pressure was significant (p < 0.0471), but that only a small portion of the variance was accounted for (R(2) = 0.149). This indicates that equinus has only a limited role in causing high forefoot pressure. Our findings suggest caution in undertaking of tendon-lengthening procedures to reduce peak forefoot plantar pressures in diabetic subjects until clearer indications are established.

Adult↗

Fractures of the tarsal bones.

Fractures involving the midtarsal bones are relatively uncommon. The morbidity associated with these injuries can be significant, however. Accurate diagnosis and appropriate treatment can help restore midfoot function and decrease the incidence of chronic pain. Treatment should preserve the function of the talonavicular joint, maintain the relative length of the medial and lateral columns, and protect the ligaments and soft tissues until adequate healing has occurred.

Foot Injuries↗

Biomechanics of procedures used in adult flatfoot deformity.

A flatfoot deformity can occur secondary to fairly obvious causes, or more subtle and less definable entities. Complicating the situation further, it is likely that the cause of an acquired flatfoot deformity in an adult is multifactorial. This likelihood makes the definition, diagnosis, and appropriate treatment of this condition a daunting task. More research is needed to define further the biomechanics of the foot and to understand the significance of the forces that combine to create flatfoot deformity.

Adult↗

The effect of posterior tibial tendon dysfunction on hindfoot kinematics.

This biomechanical study investigated the functional role of the posterior tibial tendon (PTT) in acquired flatfoot mechanics. Acquired flatfoot deformity has been attributed to PTT dysfunction; however, the progression from acute dysfunction to end-stage deformity has not been fully demonstrated. Eight human cadaver lower leg and foot specimens were used in two phases of experimental testing. In Phase 1, intact (normal) specimens were loaded to simulate (a) heel strike, (b) stance, and (c) heel rise both with and without PTT function. Then, each specimen was subjected to a procedure designed to create a simulated flatfoot deformity. The resulting flattened feet were used in Phase 2 to examine the effect of restoring PTT function to a flatfoot model. During both phases of testing, the 3-D kinematic orientation of the hindfoot complex was recorded. Small but statistically significant changes in the angular orientation of the hindfoot complex were observed, during both Phase 1 and 2 testing, when comparing the effects of a functional and dysfunctional PTT. The greatest angular changes were recorded during heel rise. For the normal foot, the small changes observed in the orientation of the hindfoot complex following release of the PTT load suggest that the intact osteo-ligamentous structure of the hindfoot is initially able to maintain normal alignment following acute PTT dysfunction. Once the soft tissues have been weakened, as in our flatfoot model, the PTT had little effect in overcoming the soft tissue laxity to correct the position of the foot.

Biomechanical Phenomena↗

Morbidity associated with ORIF of intra-articular calcaneus fractures using a lateral approach.

This is a review of 183 patients with 218 displaced intraarticular fractures of the calcaneus treated by open reduction and internal fixation. One hundred and ninety four (89%) wounds underwent primary uneventful healing. Twenty-four wounds (11%) required local wound care. One deep infection occurred in a neuropathic foot that required below-knee amputation. No free-tissue transfers, local tissue flaps or skin grafts were needed in patients who presented initially with a closed fracture. Ninety-five fractures (43.5%) required subsequent surgical procedures (hardware removal-88/95 [93% of secondary procedures]). Six patients (2.8%) had postoperative sural nerve findings. Seventeen procedures other than hardware removal were performed. There were five subtalar fusions including two subtalar distraction bone-block arthrodeses. There were seven claw toe correction procedures, four calcaneal valgus osteotomies for varus malunions and one subtalar arthrolysis at the time of hardware removal. These results suggest internal fixation of displaced intra-articular calcaneus fractures using a single lateral approach is a safe, reliable method of treatment.

Adolescent↗

Outcome after open reduction and internal fixation of Lisfranc joint injuries.

BACKGROUND: Open reduction and internal fixation has been recommended as the treatment for most unstable injuries of the Lisfranc (tarsometatarsal) joint. It has been thought that purely ligamentous injuries have a poor outcome despite such surgical management. METHODS: We performed a retrospective study of patients who underwent open reduction and screw fixation of a Lisfranc injury in a seven-year period. Among ninety-two adults treated for that injury, forty-eight patients with forty-eight injuries were followed for an average of fifty-two months (range, thirteen to 114 months). Fifteen injuries were purely ligamentous, and thirty-three were combined ligamentous and osseous. Patient outcome was assessed with use of the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and the long-form Musculoskeletal Function Assessment (MFA) score. RESULTS: The average AOFAS midfoot score was 77 points (on a scale of 0 to 100 points, with 100 points indicating an excellent outcome), with patients losing points for mild pain, decreased recreational function, and orthotic requirements. The average MFA score was 19 points (on a scale of 0 to 100 points, with 0 points indicating an excellent outcome), with patients losing points because of problems with "leisure activities" and difficulties with "life changes and feelings due to the injury." Twelve patients (25 percent) had posttraumatic osteoarthritis of the tarsometatarsal joints, and six of them required arthrodesis. The major determinant of a good result was anatomical reduction (p = 0.05). The subgroup of patients with purely ligamentous injury showed a trend toward poorer outcomes despite anatomical reduction and screw fixation. CONCLUSIONS: Our results support the concept that stable anatomical reduction of fracture-dislocations of the Lisfranc joint leads to the best long-term outcomes as patients so treated have less arthritis as well as better AOFAS midfoot scores.

Adult↗

The lateral column lengthening and medial column stabilization procedures.

The results of medial column stabilization, lateral column lengthening, and combined medial and lateral procedures were reviewed in the treatment of adult acquired flatfoot secondary to posterior tibialis tendon insufficiency. All bony procedures were accompanied by transfer of the flexor digitorum longus tendon to the medial cuneiform or stump of the posterior tibialis tendon and tendoachilles lengthening or gastrocnemius recession. Medial column fusion was performed for naviculocuneiform and cuneiform first metatarsal sag; lateral column lengthening was performed for calcaneovalgus deformity with a flat pitch angle; and combined procedures were performed for complex combined deformities. At 1 to 4 year followup of 65 feet, 88% of the feet that had lateral column lengthening, 80% that had medial column stabilization, and 88% of the feet that had medial and lateral procedures had a decrease in pain or were pain free. The lateral talar first metatarsal angle improved by 16 degrees in the patients in the lateral column lengthening group, 20 degrees in the patients in the medial column stabilization group, and 24 degrees in the patients in the combined medial and lateral procedures group. The anteroposterior talonavicular coverage angle improved by 14 degrees in the patients in the lateral column lengthening group, 10 degrees in the patients in the medial column stabilization group, and 14 degrees in the patients in the combined medial and lateral procedures group. These techniques effectively correct deformity without disrupting the essential joints of the hindfoot and midfoot.

Achilles Tendon↗

Subluxation of the talocalcaneal joint in adults who have symptomatic flatfoot.

BACKGROUND: When flatfoot is acquired during adulthood, the shape of the foot changes. In addition to a decreased arch, there may be valgus angulation of the hindfoot or abduction of the forefoot, or both. However, there is little objective information to provide a better understanding of the anatomical or morphological changes that occur in acquired adult flatfoot. We wondered if such an understanding of the three-dimensional anatomy might shed light on the pathway by which these changes occur. We designed this study to measure the three-dimensional position of the talocalcaneal joint in patients who have painful flatfoot. METHODS: Computed tomography scans of the feet of eight patients who had symptomatic flatfoot were used to construct a model of the talocalcaneal articulation. The scans were performed on a custom loading frame developed to simulate weight-bearing with the foot in a neutral position while a seventy-five-newton axial compressive load was applied. The digital data from the scans were used to make three-dimensional computer models of the articular surfaces of the talus and calcaneus of each foot. These models then were used to calculate the percentage of the articular surface that was in contact and, conversely, the percentage that was subluxated. Two surfaces were modeled for each bone; the posterior facet formed one surface, and the anterior and middle facets were combined to form the second surface. The data were compared, with use of Mann-Whitney nonparametric U analysis, with those derived from scans of the feet of four patients without a deformity of the hindfoot who served as controls. RESULTS: A mean (and standard deviation) of 68+/-9 percent of the posterior facet of the calcaneus was in contact with the talus in the patients who had flatfoot compared with 92+/-2 percent in the controls, and a mean of 51+/-23 percent of the anterior and middle facets of the calcaneus was in contact with the talus in the patients who had flatfoot compared with 95+/-6 percent in the controls. These differences were significant (p = 0.0066 for both). CONCLUSIONS: Marked subluxation of the talocalcaneal joint occurs in some patients who have symptomatic planoabductovalgus deformity.

Adult↗

Complex reconstruction for the treatment of dorsolateral peritalar subluxation of the foot. Early results after distraction arthrodesis of the calcaneocuboid joint in conjunction with stabilization of, and transfer of the flexor digitorum longus tendon to, the midfoot to treat acquired pes planovalgus in adults.

BACKGROUND: The successful correction of flatfoot in children through lengthening of the lateral column, osteotomy of the medial cuneiform, and advancement of the posterior tibial tendon led to the introduction of similar procedures to treat acquired pes planovalgus secondary to attrition or rupture of the posterior tibial tendon in adults. However, to our knowledge, no study has been published documenting whether these procedures are effective treatment for acquired flatfoot in adults. METHODS: The functional and radiographic results of complex reconstruction of a painful, flexible flatfoot associated with attrition or rupture of the posterior tibial tendon were evaluated in thirty-six patients (forty-one feet) with use of a detailed questionnaire, a comprehensive physical examination, and a review of the radiographs and the medical record. RESULTS: At a mean of thirty-four months (range, twenty-four to fifty months) postoperatively, thirty-six feet (88 percent) were less painful compared with the preoperative status or were pain-free and five of the six parameters that had been used to assess correction of the deformity radiographically had improved significantly (p<0.0001). Eight feet (20 percent) had a non-union at the calcaneocuboid joint, and thirteen feet (32 percent) had anesthesia or paresthesia of the sural nerve. Twenty-nine feet (71 percent) had had additional operations, including removal of hardware from twenty feet; bone-grafting to treat a nonunion at the site of the calcaneocuboid arthrodesis and revision of the internal fixation in four feet; a medial displacement calcaneal osteotomy because of recurrent valgus angulation of the hindfoot in two feet; and a Lapidus procedure because of a hypermobile tarsometatarsal joint with hallux valgus, a triple arthrodesis because of a nonunion at the site of the calcaneocuboid arthrodesis associated with loss of correction, and a dorsiflexion-abduction wedge osteotomy through the site of the calcaneocuboid arthrodesis (which had healed) for alignment of an overcorrected foot in one foot each. The outcomes of the procedures in thirty-five feet (85 percent) were rated by the patients as satisfactory, and thirty-three (92 percent) of the thirty-six patients (thirty-eight [93 percent] of the forty-one feet) stated that they would have the procedure again if the circumstances were similar. CONCLUSIONS: Despite the high prevalence of postoperative complications, most of our patients were satisfied with the result of the procedure after the short duration of follow-up. We believe that the relief of pain and the restoration of function achieved through effective correction of the severe pes planovalgus deformity account for the satisfactory outcomes in our patients.

Adult↗

Effect of variations in calcaneocuboid fusion technique on kinematics of the normal hindfoot.

Calcaneocuboid fusion with lengthening of the lateral column of the foot has been advocated as a method of treating flatfoot deformity. This study was designed to determine how the length of the lateral column chosen or the position of the foot selected when performing this fusion affect hindfoot kinematics in normal cadaver feet. An electromagnetic tracking system was used to monitor the positions of the talus, calcaneus, navicular, and cuboid while the intact cadaver feet were moved passively and then under reproducible loads. Calcaneocuboid fusion was then performed on these feet first with the feet in neutral position and the lateral column of normal length, then lengthened 10 mm or shortened 5 mm, and then with the lateral column lengthened 10 mm and the feet positioned in plantar flexion and eversion or dorsiflexion and inversion. Kinematic measurements were made at each stage using the same loads. Fusing the calcaneocuboid joint with lengthening or shortening the lateral column and the feet in neutral position did not affect hindfoot joint motion compared with intact. Changing the position of the foot for fusion, however, resulted in significant decreases in motion in the talocalcaneal and talonavicular joints. Tibiotalar joint motion was unaffected. This study, therefore, demonstrates that when fusing the calcaneocuboid joint, attention should be paid to maintaining a neutral position of the foot.

Arthrodesis↗

Two reconstructive techniques for flatfoot deformity comparing contact characteristics of the hindfoot joints.

The effect of two different methods of reconstruction of flatfoot deformity and the role of the posterior tibial tendon on the contact characteristics of the hindfoot joints were quantified using pressure-sensitive film. Each of 10 cadaver feet was loaded quasi-statically by an axial compressive force to simulate varying loads. First, a specimen was tested intact, then it was tested after sectioning the spring ligament and loading the specimen cyclically to create one type of flatfoot deformity. It was then tested again after reconstructing the deformity. Reconstructions used were the Dillwyn-Evans procedure (bone graft in osteotomy of the calcaneus) or the calcaneocuboid distraction arthrodesis (CCDA). We found that surgically produced flatfoot deformity altered mainly the talonavicular joint, by decreasing its contact area. The Dillwyn-Evans method had less effect on the talonavicular joint (altering 2 of 6 measured parameters) than the CCDA (3 of 6) and more effect on the anteriomedial facet (altering 3 of 6 parameters) than the CCDA (1 of 6). The Dillwyn-Evans method had more effect on the posterior facet (altering 2 of 6 measured parameters) than the CCDA (1 of 6). Function of the posterior tibial tendon had no effect on contact characteristics of the hindfoot joints after either type of reconstruction. These findings are based on measurements using a quasi-statically-loaded foot model at three selected positions, and results may be different with dynamic loading.

Aged↗

Support of the talus: a biomechanical investigation of the contributions of the talonavicular and talocalcaneal joints, and the superomedial calcaneonavicular ligament.

The goal of this study was to determine the magnitude of force transmission to the talus by its inferior articulations to provide insight into mechanisms involving acquired deformities of the hindfoot. Cadaver feet were mounted in a loading apparatus that applied axial force through the tibia and fibula as well as tensile loading of the tendons of extrinsic musculature. This also permitted positioning of the tibia in the sagittal plane. Eighteen specimens were tested in three selected positions of the gait cycle. In one series, pressure-sensitive film was inserted into the posterior and anteromedial facets of the talocalcaneal joint as well as into the talonavicular joint. In a second series, film was inserted between the talar head and the superomedial calcaneonavicular ligament. In stance position, the specimens were also tested without posterior tibial tendon (PTT) tension. Contact areas and force transmitted across the articulations were greatest in near toe-off position, in the posterior facet of the talocalcaneal joint. The talonavicular joint, the anteromedial facet of the talocalcaneal joint, and the calcaneonavicular ligament articulation showed sequentially decreasing amounts of contact area and force transmission. Mean pressures were similar across all articulations, except in the posterior facet in near toe-off position. From heel-strike to stance, to near toe-off, a trend to increasing contact area and force was noted. No difference in contact characteristics was found in the calcaneonavicular ligament articulation after PTT release. The contact force of the calcaneonavicular ligament against the talus was found to be much smaller than those of other talar articulations; however, its medially oriented direction must contribute to stabilization of the head of the talus against medial displacement. Loss of PTT tension was not found to alter the contact forces acting at the talar head in this model, which might indicate that it shares its talar stabilizing function with other structures.

Aged↗

Alterations in talar morphology associated with adult flatfoot.

To gain a better understanding on the anatomy of the factors contributing to symptomatic flatfoot, we compared the shape of the talus in feet that were flat to that in control tali from feet with a normal arch. Computed tomographic (CT) scans were performed on 9 adult patients with 10 symptomatic flatfoot deformities. CT scans of 10 feet being evaluated for acute trauma not involving the talus were randomly selected as controls. Flatfoot tali tended to be of greater overall length than the control tali, and this difference was not statistically significant. Statistically significant differences were found when comparing ratios of talar length with talar width (P = 0.011), talar length with talar height (P = 0.001) (they were long relative to their height and width), and head length with head width (P = 0.001) for individual tali from the two groups. The tali from the flatfoot group were narrower in width and shorter in height when compared with overall length and had heads that were more elongated in the transverse plane than tali in feet with a normal appearance. CLINICAL CORRELATION: When performing surgical correction of a flatfoot in an adult, appearance of the foot rather than standard radiographic parameters should be used to judge the reduction. The altered shape of the bone may alter the standard radiographic parameters.

Adult↗

Salvage procedures for calcaneus fractures.

Salvage procedures reverse the anatomic factors that cause widening and mechanical misalignment of the hindfoot. Posttraumatic arthrosis of the subtalar joint is treated by arthrodesis, using techniques that improve alignment. The easily measured goal is to restore the normal plantar alignment of the talus (Meary's line) and return the calcaneal tuberosity to the weightbearing line beneath the talus. The subtalar joint is the joint most often treated by arthrodesis, although a triple arthrodesis is sometimes required when Chopart's joint is involved.

Arthrodesis↗