PubMed Health⌕ Search

Biomedical subjects

J T Deland

Publications and source records attributed to J T Deland.

At least 19 recordsLinked to original sources
PubMed2001

A closed-loop cadaveric foot and ankle loading model.

Investigations of human foot and ankle biomechanics rely chiefly on cadaver experiments. The application of proper force magnitudes to the cadaver foot and ankle is essential to obtain valid biomechanical data. Data for external ground reaction forces are readily available from human motion analysis. However, determining appropriate forces for extrinsic foot and ankle muscles is more problematic. A common approach is the estimation of forces from muscle physiological cross-sectional areas and electromyographic data. We have developed a novel approach for loading the Achilles and posterior tibialis tendons that does not prescribe predetermined muscle forces. For our loading model, these muscle forces are determined experimentally using independent plantarflexion and inversion angle feedback control. The independent (input) parameters -- calcaneus plantarflexion, calcaneus inversion, ground reaction forces, and peroneus forces -- are specified. The dependent (output) parameters -- Achilles force, posterior tibialis force, joint motion, and spring ligament strain -- are functions of the independent parameters and the kinematics of the foot and ankle. We have investigated the performance of our model for a single, clinically relevant event during the gait cycle. The instantaneous external forces and foot orientation determined from human subjects in a motion analysis laboratory were simulated in vitro using closed-loop feedback control. Compared to muscle force estimates based on physiological cross-sectional area data and EMG activity at 40% of the gait cycle, the posterior tibialis force and Achilles force required when using position feedback control were greater.

Achilles Tendon↗
PubMed2001

Outcome following addition of peroneus brevis tendon transfer to treatment of acquired posterior tibial tendon insufficiency.

The flexor digitorum longus, the tendon most often used for transfer in posterior tibial tendon insufficiency, is one-half to one-third the size of the posterior tibial tendon. Occasionally it may be particularly small or may have been previously used for transfer. In these cases, the senior author has felt that the addition of a transfer of the Peroneus Brevis (PBr) tendon may be helpful in maintaining sufficient tendon and muscle mass to rebalance the foot. Thirteen patients who underwent this procedure were retrospectively identified and matched by age and length of follow-up to patients who underwent a more standard tendon transfer operation minus the addition of the PBr transfer. Pain and functional status were then assessed by the American Orthopaedic Foot and Ankle Society's ankle/hindfoot rating scale. Each patient was tested by an independent physical therapist to evaluate inversion and eversion strength. The mean duration of follow-up was 20.6 months (12 to 34 months). The average AOFAS score of the PBr group was 75.8 compared to 71.5 for the standard control group. There was no significant difference between the groups when inversion or eversion strengths were compared. Inversion strength and eversion strength was rated good or excellent (4 or 5) in 12 out of 13 of the PBr transfer group patients. No major complications were encountered in either group. Although it does not increase inversion strength, a PBr transfer can be used to augment a small FDL without causing significant eversion weakness. This can be useful when the FDL is particularly small or in revision surgery.

Calcaneus↗
PubMed2000

The medial crosssover toe: a cadaveric dissection.

UNLABELLED: The development of a medial crossover second toe (second toe crossing over the first toe) is not a rare clinical condition. It often occurs in the setting of hallux valgus, although not exclusively so. The resulting displacement of the second toe can cause pain in shoes, with surgical correction being problematic. The pathologic anatomy of this condition has not been fully described. In an effort to better understand it, dissection of a cadaveric specimen with a full crossover toe is presented. The dissection revealed findings not previously documented. They include medial displacement of the flexor tendons and plantar plate along with deformity of the plate itself. These changes are in addition to contracture of the medial collateral ligaments and the previously described rupture of the lateral collateral ligaments. Both the plantar plate and the collateral ligaments, the two major static soft tissue stabilizers of the lesser MP joint, were found to be significantly involved. Pull on the flexor tendons only accentuated the malalignment of the toe. CLINICAL SIGNIFICANCE: The extensive soft tissue changes explain the difficulty in achieving a successful long term correction of a full medial crossover toe with a soft tissue procedure. With attenuation of the plantar plate and medial displacement of the flexor tendons, there is an imbalance of muscle forces across the MP joint. This muscle imbalance would not be corrected by release of the medial collateral ligament, dorsal capsular release or extensor tendon lengthening. Reconstruction of the collateral ligament is at risk for incomplete correction since it is unlikely to resolve deformity in the plate if already present.

Cadaver↗
PubMed2000

Deltoid ligament strain after correction of acquired flatfoot deformity by triple arthrodesis.

Deltoid insufficiency represents a difficult surgical challenge. We have witnessed patients who have developed a valgus tibiotalar deformity following a properly positioned triple arthrodesis. To investigate whether the triple arthrodesis itself, by creating a rigid triple joint complex below the ankle, leads to increased strain of the deltoid complex, a flatfoot model was created in 8 fresh-frozen below-knee amputation specimens. Each specimen was loaded in three gait cycle (GC) positions: Heel strike (0% GC), midstance (10% GC), and heel rise (40% GC). The three components of the ground reaction force (GRF) and the tendon forces consistent with those respective positions were applied. To simulate a posterior tibial tendon insufficient state the posterior tibial tendon was not loaded. Strain at the tibiocalcaneal fibers of the superficial deltoid ligament complex was determined at each of the three foot positions. A triple arthrodesis was performed and the deltoid strains were again recorded for each position. A significant increase in the strain of the deltoid ligament was observed for only the heel rise position (p=0.007) in our cadaver model following triple arthrodesis. The results favor medializing the calcaneus following arthrodesis to protect the deltoid complex.

Adult↗
PubMed2000

Biomechanics of the ankle joint. A perspective on total ankle replacement.

The biomechanics of the ankle present a unique set of challenges for arthroplasty surgery. Its biomechanics are not simple. Although the ankle joint may seem like a hinge, it is not in a line perpendicular to the tibia. The axis of rotation does not stay constant during range of motion, despite a relative congruency of this joint. Allowing for rotational forces must be accomplished, while maintaining the stability of the joint and its components. Success of the arthroplasty depends on how successful designs can dissipate these rotational forces, while maintaining the stability of the joint. It is not yet clear from the biomechanical analysis of the normal ankle joint that this dissipation of forces has been accomplished successfully in modern implants, although early results in the semiconstrained designs are encouraging. Careful assessment of long-term follow-up will determine how close the present designs are to mimicking the unique requirements of the arthritic foot and ankle. Further work on the biomechanics of these replacements would be beneficial.

Ankle Joint↗
PubMed1999

Medial arch strain after medial displacement calcaneal osteotomy: an in vitro study.

Posterior tibial tendon dysfunction with concomitant progressive flatfoot deformity is associated with ligamentous failure along the medial arch. Medial displacement calcaneal osteotomy is being used alone and in combination with other procedures, with the expectation that it contributes to maintaining the arch. The objective of this study was to examine the effect of osteotomy on reducing medial arch strain. Whole cadaver feet were subjected to vertical loads while plantigrade. Spring ligament length was monitored using liquid metal displacement gauges. Two outcomes were examined: the length of the ligament under one-half body weight and the change in length of the ligament per unit of applied load. The medial displacement calcaneal osteotomy allowed elongation of the ligament with weightbearing, but at a shorter ligament length. This afforded the spring ligament protection from the levels of force experienced in the intact and lateral column-lengthened conditions.

Biomechanical Phenomena↗
PubMed1999

Posterior calcaneal osteotomy with wedge: cadaver testing of a new procedure for insufficiency of the posterior tibial tendon.

Insufficiency of the posterior tibial tendon is challenging to treat. When the deformity is flexible, treatment options have included tendon transfer, often combined with a medial slide calcaneal osteotomy and/or a lengthening of the lateral column. Posterior calcaneal osteotomy has been shown to give correction, although not full correction. Lengthening of the lateral column also has been shown to give correction and has been used in the more severe flexible deformities, but it involves either fusion of the calcaneocuboid joint or risk of arthritis at this joint. An osteotomy combining the calcaneal medial slide with a lengthening of the lateral column at the same osteotomy site has been tested in the laboratory. This combined osteotomy provides a lengthening of the lateral column, but it is positioned away from the calcaneocuboid joint. In this study, the osteotomy was compared with a medial slide calcaneal osteotomy and an Evans lengthening of the lateral column, using a cadaver flatfoot model. Radiographic measurements were made to evaluate correction of the planovalgus deformity after each of these procedures. There was statistically significant improved correction with the new osteotomy compared with that in a standard medial slide, and correction was comparable to that in the lengthening of the lateral column. This combined osteotomy may be a reasonable alternative when more correction is desired than can be obtained from a medial slide alone and when the surgeon wishes to avoid an osteotomy near the calcaneocuboid joint.

Cadaver↗
PubMed1999

Medial arch strain after lateral column lengthening: an in vitro study.

Posterior tibial tendon dysfunction with concomitant progressive flatfoot deformity is associated with ligamentous failure along the medial arch. Lateral column lengthening is being used alone and in combination with other procedures with the expectation that it contributes to restoring and maintaining the arch. The primary objective of this study was to examine the effect of lateral column lengthening on medial arch strain. A secondary objective was to examine the effect of subtalar, talonavicular, double and triple fusions on medial arch strain. Whole cadaver feet were subjected to vertical loads while in a plantigrade position. Spring ligament length was monitored using liquid metal displacement gauges. Two outcomes were examined: the length of the ligament and the change in length of the ligament per unit of applied load. Ligament length was unchanged after lateral column lengthening. Ligament length was decreased after talonavicular, double and triple arthrodeses, consistent with the ligament being protected by these fusions. The change in length per unit of applied load after simulated lateral column lengthening was comparable to that for the intact foot, which is consistent with the ligament remaining functional during weightbearing and not being overloaded.

Arthrodesis↗
PubMed1998

Magnetic resonance imaging of the Lisfranc ligament of the foot.

Early recognition of subtle Lisfranc injuries is important, because deformity and disability may develop after initially unremarkable radiographs. The authors studied 23 patients (mean age, 25.4 years) with a history of midfoot trauma with both radiographs and magnetic resonance imaging (MRI). When compared with the uninjured side, diastasis on radiographs ranged from 0 to 2 mm. The MRI revealed 2 intact ligaments, 3 complete tears, and 18 partial tears. All patients with complete tears had at least 2 mm more displacement between the second metatarsal and medial cuneiform, compared with the unaffected side. Because of the presence of complete or near complete rupture, seven patients underwent surgery, and the degree of rupture was confirmed. MRI of five cadaver specimens was also performed, disclosing discrete dorsal and plantar components. MRI was found to be useful in identifying Lisfranc ligament tears. If there is clear diastasis on weightbearing radiographs, MRI is not indicated. Whereas radiographic findings may be equivocal, however, MRI may accurately disclose the degree of ligament disruption.

Adolescent↗
PubMed1998

Ganglion cysts of the lower extremity: an analysis of 54 cases and review of the literature.

This article reviews 54 consecutive patients with lower extremity ganglion cysts that were surgically removed and histologically confirmed at the Hospital for Special Surgery from 1981 to 1993. Lower extremity ganglia were more common among women. Patients' ages ranged from 13 to 80 years, with the fifth and sixth decades being the most common. Size of the cysts ranged from 3 cm to 10 cm (average: 2.9 cm). Thirty-six (67%) patients had ganglion cysts of the foot and ankle, and 18 (33%) patients had ganglion cysts of the knee area. Four (7%) patients had intraosseous ganglia located in the proximal tibia, patella, and the first metatarsal head. Follow-up data of 40 (74%) patients at an average of 5.9 years (range: 1 to 12.5 years) were obtained. Satisfaction was reported by 83% of patients. Recurrence was seen in 10% of patients, and a report of no or mild pain was given by 86% of the group. Patients who underwent revision ganglion excision had inferior results. Only 25% reported satisfaction and 50% reported no or mild pain. Patients who underwent curettage of an intraosseous ganglion appeared to have superior results. All patients reported satisfaction and no or mild pain. The performance of a concomitant surgical procedure, the anatomic region of the ganglion, or type of postoperative immobilization did not appear to affect the outcome.

Adolescent↗
PubMed1997

Achilles tendon insertion: an in vitro anatomic study.

Seventeen adult fresh-frozen below-knee amputation cadaver specimens were studied. Calcific Achilles tendinitis was present in three specimens. After exposing the Achilles tendon insertion on the calcaneus, the insertion was outlined with waterproof paint. The specimens were photographed on a special plexiglass apparatus to highlight important findings. For the purpose of showing the length of insertion on lateral radiographs, lead beads were placed on the most superior and most inferior aspects of the insertion. All specimens showed that the tendon terminated at the medial and lateral bone borders of the calcaneus without significant extension around the medial or lateral wall. All specimens revealed a greater distance of insertion on the medial calcaneus than on the lateral side. In the specimens that had calcific Achilles tendinitis, the posterior bone surface of the spurs was devoid of tendinous insertion, instead, the insertion occurred between the spur and the posterior wall of the calcaneus. All spurs were located laterally at the most inferior border of the tendon insertion.

Achilles Tendon↗
PubMed1997

Pes planus in patients with posterior tibial tendon insufficiency: asymptomatic versus symptomatic foot.

Bilateral weightbearing anteroposterior and lateral radiographs were analyzed in 43 patients with a clinical diagnosis of posterior tibial tendon insufficiency by two independent observers. The radiographs of each patient's asymptomatic foot was considered to serve as the control for the preexistance of pes planus. The radiographs were assessed for the severity of flatfoot deformity, the degree of talonavicular coverage, the talometatarsal angle, the calcaneometatarsal angle, the cuneiform to ground height and the cuneiform to fifth metatarsal height. Interobserver correlations were assessed. Results indicated that there was a high interobserver correlation for the values measured, making these angles reproducible among observers. Strong correlations were found in the degree of severity of flatfoot deformity between the asymptomatic and symptomatic feet as well as the values used to assess pes planus (i.e., similar radiographic measurements on the opposite side). The data suggest that patients with posterior tibial tendon insufficiency often have a preexisting flatfoot. This substantiates our belief that a preexisting flexible flatfoot, although far from the determining factor, is one of several etiological factors in the development of posterior tibial tendon insufficiency.

Adult↗
PubMed1997

Chronic ankle pain caused by osteoid osteoma of the neck of the talus.

Five patients with osteoid osteomas of the talar neck were treated at the Hospital for Special Surgery between 1981 and 1992. The course of care leading to definitive diagnosis and treatment was reviewed. All five of the patients had night pain relieved by aspirin or nonsteroidal anti-inflammatory drugs. One of the five reported associated trauma. The average time from onset of symptoms to correct diagnosis was 2.5 years. Juxta-articular osteoid osteoma can cause a small spur that resembles a traction spur on the neck of the talus. Anterior ankle impingement was the most common misdiagnosis. Initial treatments included arthroscopic spur debridement or synovectomy, casting for fracture, and repeated nerve blocks for reflex sympathetic dystrophy. The five patients were cured by en bloc excision of the lesion. In the diagnosis of osteoid osteoma, a history of relief of pain with aspirin is important. Plain radiographs and a bone scan are useful. Fine cut computed tomography scanning or magnetic resonance imaging are the best studies for making a definitive diagnosis. Localization by computed tomography guided needle placement or intraoperative radionuclide scanning are recommended to find the lesion for excision. Intraoperative radiographs of the excised lesion should be used to confirm complete removal.

Adult↗
PubMed1997

Motion of the hindfoot after simulated arthrodesis.

Arthrodesis of the subtalar joint, triple arthrodesis (involving the subtalar, talonavicular, and calcaneocuboid joints), double arthrodesis (involving the talonavicular and calcaneocuboid joints), arthrodesis of the talonavicular joint, and arthrodesis of the calcaneocuboid joint were simulated in a cadaver model, and the range of motion of each joint not involved in the simulated arthrodesis was measured with a three-dimensional magnetic space tracking system. The excursion of the posterior tibial tendon was also measured under all of these conditions. We found that any combination of simulated arthrodeses that included the talonavicular joint severely limited the motion of the remaining joints to about 2 degrees and limited the excursion of the posterior tibial tendon to 25 per cent of the preoperative value. Simulated arthrodesis of the calcaneocuboid joint had little effect on the range of motion of the subtalar joint, and it reduced the range of motion of the talonavicular joint to a mean of 67 per cent of the preoperative value; a mean of 73 per cent of the excursion of the posterior tibial tendon was retained. After simulated arthrodesis of the subtalar joint, a mean of 26 per cent of the motion of the talonavicular joint, 56 per cent of the motion of the calcaneocuboid joint, and 46 per cent of the excursion of the posterior tibial tendon was retained. The talonavicular joint is the key joint of the triple joint complex. The talonavicular joint had the greatest range of motion, and simulated arthrodesis of this joint essentially eliminated motion of the other joints of the complex.

Arthrodesis↗
PubMed1995

Selective hindfoot arthrodesis for the treatment of adult acquired flatfoot deformity: an in vitro study.

An acquired flatfoot deformity with significant laxity at the transverse tarsal joint was created experimentally and the amount of correction that was obtained with selective hindfoot fusions was measured radiographically. Results showed that the talonavicular, double (talonavicular and calcaneocuboid), and triple arthrodeses were able to fully correct the deformity, including correction of hindfoot valgus with just a talonavicular fusion. Subtalar and calcaneocuboid fusions failed to completely correct the deformity. This study provides experimental evidence that although the triple joints are interconnected, they differ with respect to their ability to malalignment. We conclude that talonavicular or double arthrodesis will correct deformity in a flatfoot with considerable laxity through the transverse tarsal joint, but that a subtalar fusion will not provide consistent correction.

Adult↗
PubMed1995

Anatomy of the plantar plate and its attachments in the lesser metatarsal phalangeal joint.

The plantar plate is a rarely seen, yet central structure to the lesser metatarsal phalangeal (MP) joint. Thirty cadaver lesser MP joints were studied to obtain a detailed description of the plate, including its dimensions, connections, and histology. The plate was found to be made of fibrocartilage with fiber orientation which suggests that it withstands tensile loads in line with the plantar fascia as well as the compressive loads from the metatarsal head. The plantar plate was the most substantial distal insertion of the plantar fascia. Impressive plantar plate attachments were noted to the proximal phalanx, the major longitudinal bands of the plantar fascia, and the collateral ligaments. The plate and collateral ligaments formed a substantial soft tissue box connected to the sides of the metatarsal head. From the dissections, it is apparent that malposition of the toe at the MP joint is likely over time to be associated with pathology in both the collateral ligaments and the plate. Because of these attachments and a close association with the flexor tendons to the lesser toe, the plate can be compared with the sesamoid mechanism of the first MP joint.

Adult↗