Investigation of factors related to the occurrence of osteochondral lesions of the talus by 3D bone morphology of the ankle.

AIMS: The aims of this study were to evaluate the morphology of the ankle in patients with an osteochondral lesion of the talus using 3D CT, and to investigate factors that predispose to this condition. PATIENTS AND METHODS: The study involved 19 patients (19 ankles) who underwent surgery for a medial osteochondral lesion (OLT group) and a control group of 19 healthy patients (19 ankles) without ankle pathology. The mean age was significantly lower in the OLT group than in the control group (27.0 vs 38.9 years; p = 0.02). There were 13 men and six women in each group. 3D CT models of the ankle were made based on Digital Imaging and Communications in Medicine (DICOM) data. The medial malleolar articular and tibial plafond surface, and the medial and lateral surface area of the trochlea of the talus were defined. The tibial axis-medial malleolus (TMM) angle, the medial malleolar surface area and volume (MMA and MMV) and the anterior opening angle of the talus were measured. RESULTS: The mean TMM angle was significantly larger in the OLT group (34.2°, sd 4.4°) than in the control group (29.2°, sd 4.8°; p = 0.002). The mean MMA and MMV were significantly smaller in the OLT group than in the control group (219.8 mm2, sd 42.4) vs (280.5 mm2, sd 38.2), and (2119.9 mm3, sd 562.5) vs (2646.4 mm3, sd 631.4; p < 0.01 and p = 0.01, respectively). The mean anterior opening angle of the talus was significantly larger in the OLT group than in the control group (15.4°, sd 3.9°) vs (10.2°, sd 3.6°; p < 0.001). CONCLUSION: 3D CT measurements showed that, in patients with a medial osteochondral lesion of the talus, the medial malleolus opens distally, the MMA and MMV are small, and the anterior opening angle of the talus is large. This suggests that abnormal morphology of the ankle predisposes to the development of osteochondral lesions of the talus. Cite this article: Bone Joint J 2018;100-B:1487-90.

Valgus deformity of the ankle following harvesting of a vascularized fibular graft in children.

Progressive valgus ankle deformity is a problematic postoperative donor-site morbidity of a vascularized fibular graft in children. To prevent this complication, tibiofibular metaphyseal synostosis (the Langenskiöld procedure) has been recommended. The authors objectively evaluated the preventive and therapeutic effects of this procedure on five children who had received free vascularized fibular grafts. Their average age at the time of operation was 3 years (range: 1 to 9 years). The Langenskiöld procedure was performed primarily in four patients, and not in one patient. The anteroposterior (A-P) mortise angle and the empirical axis of the donor-site ankle were measured radiographically. With regard to the A-P mortise angle, four of five patients showed valgus with a mild lateral wedging of the distal tibial epiphysis. The patient who did not receive the operation showed the largest A-P mortise angle and mild osteoarthritic changes. The empirical axis exceeded normal range in all of the five patients. These observations indicated that valgus deformity of the ankle in children after harvesting a vascularized fibular graft is inevitable, even if the Langenskiöld procedure is performed. The procedure can delay the ankle valgus. The authors recommend close follow-up of the children who receive the Langenskiöld procedure after harvesting a vascularized fibular graft.

Mechanical behavior of the Lisfranc and dorsal cuneometatarsal ligaments: in vitro biomechanical study.

OBJECTIVES: To define the anatomy and mechanical properties of two ligaments stabilizing the medial tarsometatarsal joints: the Lisfranc ligament and the dorsal cuneometatarsal ligament. DESIGN: Cadaveric study in normal feet. SETTING: Biomechanics laboratory. PATIENTS OR PARTICIPANTS: Twelve fresh-frozen cadaveric feet were studied. INTERVENTION: The Lisfranc and dorsal cuneometatarsal ligaments were dissected, dimensions measured, and material properties determined with a servohydraulic MTS machine on bone-ligament-bone preparations. MAIN OUTCOME MEASUREMENTS: Stiffness, strain, stress, modulus, failure load, ligament length, width, thickness, and cross-sectional area were determined. RESULTS: Dorsal ligament stiffness was 66.3+/-18.3 newtons per millimeter and the Lisfranc ligament stiffness was 189.7+/-57.2 newtons per millimeter. The failure load of the dorsal ligament averaged 150.7+/-33.1 newtons and for the Lisfranc ligament, 368.8+/-126.8 newtons. CONCLUSIONS: The stiffness and load to failure of the dorsal cuneometatarsal ligament were much higher than anticipated, which indicates that it contributes significantly to stabilizing the second metatarsal to the first cuneiform.

Calcaneocuboid distraction arthrodesis for posterior tibial tendon dysfunction and flatfoot: a cadaveric study.

Nine fresh-frozen foot specimens were studied to determine the mechanical behavior of the foot using calcaneocuboid distraction arthrodesis, an operation designed for treatment of posterior tibial tendon dysfunction with flatfoot deformity. Flatfoot deformity was created in cadaveric specimens, and to simulate toe-off phase of gait, loads were applied to the plantar surface of the foot and six tendons. Three-dimensional tarsal bone positions were determined with a magnetic tracking system. With ligament sectioning, flatfoot deformity was observed and average arch height decreased 53 +/- 3.5 mm. Height arch increased after calcaneocuboid distraction arthrodesis an average of 3.2 +/- 3.6 mm and was less than normal arch at an average of 2.1 +/- 2.4 mm. Metatarsotalar alignment compared with flatfoot improved after calcaneocuboid distraction arthrodesis in adduction and inversion to the extent that these were not significantly different from intact foot positions. Calcaneotalar position improved after calcaneocuboid distraction arthrodesis in adduction and inversion. Calcaneocuboid alignment compared with flatfoot improved after calcaneocuboid distraction arthrodesis in adduction, plantar flexion, and eversion, but compared with an intact foot was overcorrected in all three planes of motion. Arch alignment in simulated toe-off phase of gait in cadaveric feet was improved significantly with calcaneocuboid distraction arthrodesis but was not reduced anatomically.

Cartilage degeneration in talocrural and talocalcaneal joints from Japanese cadaveric donors.

In a study human cadavers, degenerative change (DC) was observed more frequently on articular surfaces of the talocrural joint (55. 8%) than on the articular surfaces of the talocalcaneal joint (29. 5%). In the talocrural joint, the anteromedial segments of the tibial plafond, talar dome, and the medial malleolar facet exhibited a high frequency of DC. Moreover, most DCs were found to coexist in multiple segments that often included both the tibial and talar sides. In the talocalcaneal joint, by contrast, DC tended to be distributed diffusely over the articular surfaces. If the DC occurred initially and progressed to a cartilage defect, it tended to be restricted to a certain portion of the talocalcaneal joint. Mirror-image lesions were observed much less frequently than expected in both the talocrural (28.3%) and talocalcaneal joint (25. 0%). Notably, these lesions were not usually observed even if the DC had progressed to a cartilage defect. We considered that the DC tended to advance to the adjacent segment on the same side rather than to the complementary segment on the opposite side. We demonstrated that the more multiple DC lesions were present in the talocrural joint, the more often DC occurred in the talocalcaneal joint. Consequently, we believe than multiplicity of DCs is more critical for the downward joint-to-joint progression of DC than is increased severity.

Role of medical capsule and transverse metatarsal ligament in hallux valgus deformity.

The role of the medial capsule and transverse metatarsal ligament in hallux valgus deformity including stability of the first metatarsophalangeal and adjacent joints was investigated in vitro. The three-dimensional positions of the proximal phalanx, first metatarsal, and second metatarsal before and after sectioning the medial capsule and metatarsal ligament were measured using a magnetic tracking system. Valgus deformity of the hallux increased with medial capsule sectioning an average of 22.3 degrees +/- 6 degrees. Valgus deformity of the hallux increased with medial capsule and metatarsal ligament sectioning an average of 27.4 degrees +/- 9.1 degrees. Valgus deformity of the hallux did not change significantly after sectioning the metatarsal ligament only. No significant changes were found in varus and eversion of the first metatarsal, in valgus of the second metatarsal, in the distance between first and second metatarsal heads after sectioning the medial capsule, or in the metatarsal ligament. This study shows the importance of the medial capsule in hallux valgus deformity. The transverse ligament did not contribute substantially to cause the deformity.

Quantitative analysis of the intrinsic muscles of the foot.

BACKGROUND: Understanding muscle architecture of the foot may assist in the design of surgical procedures such as tendon transfer, biomechanical modeling of the foot, prosthesis design, and analysis of foot function. There is limited published information regarding foot intrinsic muscle architecture. METHODS: Eleven fresh-frozen cadaveric feet were studied from eight males and three females. Twenty-eight intrinsic muscles were dissected in each foot, and measurements of fiber length, muscle length, and muscle volume obtained using calipers and water displacement technique. The physiologic cross-sectional area, fiber/muscle length ratio, muscle mass fraction, and tension fraction were then calculated. RESULTS: Intrinsic muscle length was related to foot size. The mean fiber length ranged from 13.6 mm (first plantar interosseous) to 28.0 mm (second extensor digitorum brevis). The mean muscle length ranged from 24.8 mm (adductor hallucis transverse) to 115.8 mm (abductor hallucis). The mean muscle volume ranged from 0.4 cc (fifth lumbrical) to 15.2 cc (abductor hallucis). The physiologic cross-sectional area ranged from 0.28 cm2 (second and third lumbrical) to 6.68 cm2 (abductor hallucis). The fiber/ muscle ratio ranged from 0.20 (abductor hallucis) to 0.82 (adductor hallucis transverse). The mass fraction ranged from 0.33% (fifth lumbrical) to 16.59% (abductor hallucis). The tension fraction ranged from 0.34% (fifth lumbrical) to 15.37% (abductor hallucis). CONCLUSIONS: The abductor hallucis and adductor hallucis oblique had much greater physiologic cross-sectional areas compared to those of the other intrinsic muscles. The lumbrical muscles had relatively low physiologic cross-sectional areas. These observations illustrate the underlying structural basis for the functional capacities of the intrinsic muscles of the foot.

Physiological elongation of ligamentous complex surrounding the hindfoot joints: in vitro biomechanical study.

Ligaments surrounding the hindfoot joints play an important role in hindfoot stability. This in vitro study investigated anatomical and biomechanical characteristics of nine major ligamentous structures, including length and orientation at neutral position and physiological elongation with the foot in five different positions relative to the neutral position. The results showed that ligament elongation depended on the ligament length, orientation in neutral position, and movement of bones to which they were attached.

Control method for preloading with priority information in an integrated radiology information system/picture archiving and communication system.

More than 10 years has passed since the concept of picture archiving and communication systems (PACS) was first proposed. A great deal of effort has been expended to make PACS suitable for routine use in clinical settings, but only a few systems are currently used in this manner. A major reason is the lack of the assurance of throughput equivalent to that of a conventional system based on order sheets and analog films. In this report, two techniques to increase throughput have been introduced and studied. The first is the preloading of data elements from the various information systems and the PACS. The second is the use of the priority information to rank order the examinations placed on the list for interpretation. We have applied these techniques to an actual system and have measured the distribution of time for processing examinations. These two techniques appear to make PACS useful in routine practice because most of the urgent cases were interpreted within the target time of 40 minutes.

Preliminary time-flow study: comparison of interpretation times between PACS workstations and films.

Toshiba Hospital installed a PACS and RIS in the diagnostic imaging department along with a hospital-wide HIS in May 1993. Our PACS includes three diagnostic workstations each of which is provided with six monochrome CRT monitors. The diagnostic workstations have been used as the primary tools for interpretation of almost all radiographic images. The actual image interpretation time was measured for diagnostic workstations (237 examinations) and for conventional hard-copy films (219 examinations) for CR, CT, and MRI. The difference in interpretation times between diagnostic workstations and films was not significant. With regard to image interpretation time, diagnostic workstations are thought to be acceptable for practical image reading.

Three-dimensional corrective osteotomy for treatment of cubitus varus after supracondylar fracture of the humerus in children.

Cubitus varus deformity after supracondylar fracture of the humerus in children generally includes deformities of varus, hyperextension, and internal rotation. Presently almost all corrective osteotomies for treatment of cubitus varus deformity have been limited to correction of only the varus or of the varus and hyperextension deformity. Electromyographic study and stick picture motion analysis have revealed unphysiological joint motion and muscle activity around the joint in elbows with cubitus varus, hyperextension, and internal rotation deformity. On this basis we have successfully attempted simultaneous correction of all three deformities. The end results in 41 elbows have been satisfactory. In conclusion, we recommend simultaneous correction of the three elements of cubitus varus deformity to restore anatomic alignment of the elbow joint.

Blocking action of terodiline on calcium channels in single smooth muscle cells of the guinea pig urinary bladder.

The blocking action of terodiline, a nonspecific organic Ca++ antagonist, on smooth muscle Ca++ channels of the guinea pig urinary bladder was investigated. Inward Ca++ currents were recorded from smooth muscle cells isolated from the urinary bladder using the whole-cell patch-clamp technique. In the absence of terodiline, a use-dependent reduction in the amplitude of inward Ca++ current was observed at a stimulus frequency of 0.2 Hz. When terodiline (1-10 microM) was applied, the use-dependent reduction was accelerated markedly, depending on the stimulus frequency. The blocking action of terodiline was also dose-dependent; the Kd value as measured at the end of 20 times repetitive stimulation at 0.2 Hz was 1.7 microM. In addition to such a use-dependent block, terodiline produced a hyperpolarizing shift in the steady-state inactivation curve. The results suggest that terodiline preferentially binds to the Ca++ channel in the open state and also in the inactivated state.

Contractile responses to electrical field stimulation and ATP in guinea-pig urinary bladder.

1. The responses of guinea-pig urinary bladder smooth muscle to intramuscular nerve stimulation were investigated by isometric tension recording. 2. The nerve mediated contractions, evoked by field stimulation with a stimulus of 0.5 msec duration, a frequency of 15 Hz and a voltage of 50 V, were inhibited by atropine (10(-6) M) and alpha, beta-MeATP (10(-4) M) to about 80% and 20%, respectively, of control. 3. Simultaneous application of atropine (10(-6) M) and alpha, beta-MeATP (10(-4) M) abolished the contraction evoked by selective nerve stimulation. 4. Terodiline (10(-4) M), one of Ca2+ antagonists, inhibited the contraction evoked by both nerve selective stimulation and exogenously applied ATP. 5. Based on these results we suggested that in guinea-pig urinary bladder, ATP was a predominant excitatory transmitter and the nerve-mediated contraction and exogenous ATP were mainly dependent upon Ca2+ influx.