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Biomedical subjects

S G Trevino

Publications and source records attributed to S G Trevino.

14 recordsLinked to original sources
PubMed2001

Calcaneocuboid stability: a clinical and anatomic study.

Injuries to the midtarsal joints are relatively uncommon and often unrecognized entities. Acute and chronic instability patterns to the calcaneocuboid joint can occur from such injuries. No previous determinations of normal calcaneocuboid laxity have been reported. Utilizing a previously described technique, stress radiographs were performed in human cadaveric specimens following serial sectioning of the ligamentous supports of the calcaneocuboid joint. Significant differences in calcaneocuboid gap and angle occurred between unstressed and stressed conditions. Cadaveric specimen testing determined that the dorsal and plantar calcaneocuboid ligaments both provide significant contributions to joint stability. Prior to defining pathologic states of joint laxity, normal ranges of stability must be determined. By more clearly defining normal stability of the calcaneocuboid joint and its ligamentous contributions, greater insight into the diagnosis and treatment of calcaneocuboid instability can be obtained.

Adult↗
PubMed2000

The effects of early mobilization in the healing of achilles tendon repair.

Twenty-four male New Zealand rabbits underwent suture repair of a tenotomy of the left achilles tendon. The rabbits were randomized into two groups of 12 animals; in group (A), the ankle was immobilized by pinning for 35 days, while in the group (B), the ankle was immobilized for only 14 days followed by active mobilization. Following sacrifice at 35 days postoperatively, the retrieved tendons were evaluated by biomechanical testing and histologic examination. Approximately 50% of stretching occurred in the first four days; average overall elongation was 9.5+/-1.0 mm and 12.7+/-1.5 mm (p=0.102) and average stiffness recovery was 67.4+/- 2.0% and 82.9 +/- 1.9% (p=0.0004) for groups A and B respectively. Histologically both groups demonstrated traces of disorganized neo-collagen fibers at the repair site as early as the fourth day with subsequent appearance of more mature collagen. The results obtained from our study favor early mobilization of the repaired tendon, which seems to restore the functional properties of the tendons more rapidly than continuous immobilization of an identical surgical repair.

Achilles Tendon↗
PubMed1999

Open versus closed repair of the Achilles tendon: an experimental animal study.

This experimental animal study compared the healing patterns between open and closed treatments of Achilles tendon tenotomies. Twenty-four male New Zealand rabbits underwent tenotomy of the left Achilles tendon and were randomized into two groups, treated with either open surgical repair or closed management. After the death of the animal, the retrieved tendons were submitted for biomechanical and histological testing. The total elongation of the open treatment group was 9.5+/-1.0 mm compared with 21.2+/-3.4 mm for the closed treatment group (P = 0.008), and the regain of stiffness was 67.4+/-2.0% and 48.9+/-5.3%, respectively (P = 0.132). Histological evaluation demonstrated similar healing patterns in both groups.

Achilles Tendon↗
PubMed1998

Biomechanical consequences of sequential plantar fascia release.

Plantar fascia release has long been a mainstay in the surgical treatment of persistent heel pain, although its effects on the biomechanics of the foot are not well understood. With the use of cadaver specimens and digitized computer programs, the changes in the medial and lateral columns of the foot and in the transverse arch were evaluated after sequential sectioning of the plantar fascia. Complete release of the plantar fascia caused a severe drop in the medial and lateral columns of the foot, compared with release of only the medial third. Equinus rotation of the calcaneus and a drop in the cuboid indicate that strain of the plantar calcaneocuboid joint capsule and ligament is a likely cause of lateral midfoot pain after complete plantar fascia release.

Biomechanical Phenomena↗
PubMed1998

Tibiotalocalcaneal arthrodesis: anatomic and technical considerations.

In the first of this two-part cadaver investigation, we inserted a specially designed, pointed device (simulating a 12-mm nail) in an antegrade fashion in each of eight fresh-frozen cadaver tibial specimens; the tibial isthmus was used as a centralizing guide. The exit point was noted, and the specimen was dissected to identify the structures at risk. In all specimens, we found that the device placed the lateral plantar artery and nerve at risk (average minimal distance from device to structure, 0 mm) and that damage to the flexor hallucis brevis and plantar fascia occurred. In addition, in six of the eight specimens, the device skewered or skived the flexor hallucis longus tendon. We also noted that in each specimen the exit point was the sustentaculum tali, not the body of the calcaneus as expected. Thus, there was less calcaneal bone-to-rod interface for stability, and distal locking would be less effective in the lateral-to-medial direction because of the lack of medial bone stock. On the basis of the results of the first portion of the study, we investigated an alternative approach to retrograde tibial nailing to reduce the risk of injury to the plantar and medial structures of the foot. We performed a medial malleolar resection, medially displaced the talus, inserted the device in an antegrade fashion, and dissected the specimens to analyze the structures at risk. We found that malleolar resection and medial translation of the distal extremity an average of 9.3 mm (range, 7-11 mm) increased the average minimal distance from the tip of the device to the neurovascular bundle to 18.4 mm (range, 14-32 mm). We also found that there was no damage to the flexor hallucis longus and that all eight specimens demonstrated bony contact completely surrounding the nail device within the tuberosity portion of the calcaneus (assessed by postoperative radiographs). The results of this study suggest that malleolar resection and medial translation of the distal extremity before retrograde nailing of the tibia may reduce the risk of vital structure injury and enhance the rigidity of the fixation.

Arthrodesis↗
PubMed1996

Callosities, corns, and calluses.

Inappropriate shoes, abnormal foot mechanics, and high levels of activity produce pressure and friction that lead to corns and calluses. Most lesions can be managed conservatively by proper footwear, orthoses, and, if necessary, regular paring. The lesions usually disappear when the causative mechanical forces are removed. Surgery is rarely indicated and should be specifically aimed at correcting the abnormal mechanical stresses.

Callosities↗
PubMed1996

Partial Achilles tendon ruptures associated with fluoroquinolone antibiotics: a case report and literature review.

Fluoroquinolone antibiotics (such as olprofloxacin, pefloxacin, ofloxacin, norfloxacin, temafloxacin, etc.) have recently been implicated in the etiology of Achilles tendinitis and subsequent tendon rupture. We report on a patient with bilateral partial Achilles tendon ruptures associated with ciprofloxacin therapy and present a review of the current literature on this increasingly recognized complication. Treatment with fluoroquinolones should be discontinued at the first sign of tendon inflammation so as to reduce the risk of subsequent rupture. Magnetic resonance imaging is useful in distinguishing between Achilles tendinitis and partial tendon rupture.

Achilles Tendon↗
PubMed1995

Operative treatment of acute displaced intra-articular calcaneus fractures.

A retrospective study of 18 operatively treated calcaneal fractures was conducted. The fractures were all type II and type III fractures according to the classification system of Crosby et al. The average follow-up was 32 months and consisted of subjective and objective criteria. The findings were compared with the results of nonoperative treatment reported by Crosby et al. The findings suggests that type II fractures have a similar outcome when either operative or nonoperative treatment is used. Type III fractures, however, fared considerably better with operative intervention when compared with those treated with nonoperative techniques.

Accidental Falls↗
PubMed1995

Controversies in tarsometatarsal injuries.

Lisfranc injuries still remain a problematic situation in many clinical cases. Although thought to be an uncommon problem, they are actually a common injury. This article serves to make the clinician aware of the many recent changes in diagnosis and treatment. Emphasis is placed on the precise diagnosis of this condition and subsequent follow-up.

Ankle Injuries↗
PubMed1994

Management of acute and chronic lateral ligament injuries of the ankle.

Acute and chronic lateral ligament injuries of the ankle represent a common but persistent problem to orthopedic specialists. A comprehensive physical examination and classification system were proposed as an approach to this problem. Guidelines for both conservative and surgical management for acute and chronic injuries are described. A comparison of the most common lateral ligament repairs is provided, with emphasis on the benefits of the so-called anatomic repair.

Ankle Injuries↗
PubMed1991

Chronic lateral ankle instability.

Chronic lateral ankle instability may be present in as many as 10% to 30% of people suffering from acute lateral ankle ligament injuries. Ankle instability has been referred to as either functional instability or mechanical instability. Management options consist of either nonoperative or operative treatment, with the majority of the literature emphasizing operative management for chronic instability. Long-term studies assessing the different types of available operative repairs have now been published. This review article discusses chronic lateral ankle ligament instability from a functional, anatomical point of view. The indications for treatment, nonoperative and operative treatment, as well as the biomechanical information available regarding these methods of treatment are considered. The major emphasis of this review is discussion and analysis of the many different surgical treatment options. Following this review, we presently recommend anatomical repair to the bone of both the anterior talofibular ligament and the calcaneofibular ligament, together with imbrication of the ligaments. In patients with hypermobility, long-standing instability, or arthritis, reconstruction using the Chrisman-Snook technique is recommended.

Ankle Joint↗
PubMed1987

Occurrence of the plantaris tendon in patients sustaining subcutaneous rupture of the Achilles tendon.

Many surgeons treat closed subcutaneous rupture of the Achilles tendon with primary surgical repair. Reinforcement of the primary repair can be accomplished easily using the plantaris tendon. Unfortunately, in the population of patients who sustain this injury, the plantaris is absent in 60% of patients. This is a statistically significant difference when compared to the absence of the plantaris tendon of less than 10% in reported cadaveric studies.

Achilles Tendon↗