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The hydrothermal fluids that deposited the ores of the Viburnum Trend of the Southeast Missouri district have long been recognized to be sedimentary basinal brines. The major element composition of these brines has been well characterized; however, there have been no attempts to measure their metal content, which is only loosely constrained by theoretical solubility relations. The present study is an effort to assess the metal content of these mineralizing brines by analyzing fluid inclusions from gangue minerals in the Viburnum Trend using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and microthermometry. By focusing on gangue minerals instead of metal sulfide minerals, interferences from the mineral matrix are avoided. A high priority was to determine whether brines of anomalously high metal content were circulating through southeast Missouri during the time of Mississippi Valley-type mineralization. Fluid inclusions in dolomite, quartz, and calcite gangue from throughout the Viburnum Trend and representative of the entire paragenesis were analyzed. None of the inclusions contained measurable quantities of Pb, Zn, or Cu and only a few contained measurable quantities of Ba, which ranged from about 100 to 500 ppm. Where detection limits were not exceeded, they indicated maximum possible concentrations of the element in the fluid inclusion. Maximum possible concentrations varied from inclusion to inclusion and were controlled by the mass of analyte within the fluid volume—the larger or more saline the inclusion, the lower the detection limit. These results showed that the fluid that deposited quartz, calcite, and most of the dolomite gangue in the Viburnum Trend is unlikely to have had order-of-magnitude concentrations of Pb and Zn higher than 102 ppm or order-of-magnitude concentrations of Cu higher than 101 ppm. Concentrations of Pb and Zn during deposition of stage 3 dolomite could not have been higher than 103 ppm, and concentrations of Cu could not have been higher than 102 ppm. These upper limits on possible metal concentrations, with the principal exception of those in stage 3 dolomite fluid inclusions, are of magnitude similar to the highest measured concentrations of Pb, Zn, Cu, and Ba found in typical sedimentary brines. Thus, the brines responsible for depositing gangue minerals in the Viburnum Trend are unlikely to have had higher ore metal concentrations than typical basinal brines. The lack of temporal overlap between gangue and metal sulfide deposition, and the higher K/Na and lower Ca/Mg ratios in fluid inclusions in the gangue minerals compared with fluid inclusions in the metal sulfides, leaves open the possibility that the metal content of the fluid that deposited the sulfides was different from that responsible for depositing gangue. However, the data show that fluid entering the Southeast Missouri district was not pervasively metal rich throughout time, and that if metal-enriched fluid ever entered the district it did so at discrete intervals.

Brachymetatarsia is an uncommon condition, and when present, it is usually asymptomatic. A case report demonstrating the use of distraction lengthening for symptomatic multiple congenital short metatarsals is presented. A 15-year-old female with congenital short third and fourth metatarsals was treated for painful transfer lesions under the second and fifth metatarsal heads and a secondary hallux valgus deformity. Surgical correction with a chevron osteotomy, soft tissue reconstruction of the second toe, and distraction lengthening of the third and fourth metatarsals was performed. Three years after treatment, the patient has an excellent clinical correction, with no evidence of recurrent transfer lesions. To our knowledge, this is the first report demonstrating the use of distraction lengthening without supplemental bone graft for multiple short metatarsals in a single extremity.

A 64-year-old woman was treated for an idiopathic complete rupture of the posterior tibial tendon with transfer of the flexor digitorum longus tendon to the navicular. After an initial excellent result, she returned 41 months later after experiencing a sudden pop in the medial retromalleolar area, followed by progressive medial ankle pain. At reoperation, a complete rupture of the flexor digitorum longus tendon was noted at its insertion into the navicular. Reconstruction was performed utilizing a sliding lengthening of the flexor digitorum longus tendon and reattachment to the navicular with a suture anchor. Clinical improvement was noted at the 12-month follow-up evaluation. This case presentation is of clinical interest, as late acute failure of a flexor digitorum longus tendon transfer for posterior tibial tendon rupture has not been reported previously.

Twelve patients with rupture of the anterior tibial tendon are presented. Nine patients were aware of an acute event prior to their symptom onset and three were not aware of any acute event. Complete rupture of the tendon was noted in 10 patients and incomplete rupture was seen in two patients. Treatment was individualized based on age, etiology, preinjury function, patient health, and personal considerations. Five patients were treated without surgery. Three preferred no orthotic devices, and two believed their function was improved with an ankle-foot orthosis. Seven patients were treated operatively using a variety of individualized reconstructive techniques. All operatively treated patients demonstrated increased function and strength. Based on our findings, operative reconstruction is recommended in appropriate patients.

Two patients with combined rupture of the anterior tibial tendon and posterior tibial tendon are described. Both were elderly women with a gradually progressive valgus deformity of the ankle/hindfoot and severe pain. Arthrodesis procedures were performed in both patients; however, postoperative complications prevented significant clinical improvement. This combined tendon rupture is presented to document a new clinical entity.

We have treated seven patients with dislocation or recurrent subluxation of the posterior tibial tendon. The diagnosis of dislocation was made based on the patient's symptoms, physical examination, and magnetic resonance scanning. All patients were treated with surgical repair, which was modified according to the operative findings. The operative findings included tenosynovitis, a shallow or incompetent flexor groove, and tearing or absence of the flexor retinaculum. At an average of 28 months following surgery, all patients were markedly improved and six returned to their preinjury level of activity.