Osteochondritis of the first metatarsal sesamoids

Osteochondritis of the sesamoids of the hallux is an infrequently presenting condition of uncertain etiology. The diagnosis is usually established by the typical clinical presentation, fragmentation of the affected sesamoid seen on the axial-view radiogram and increased uptake on the 99mTc bone scan. The condition is usually refractory to conservative treatment and is best treated by excision of the affected sesamoid.     

Elongation of the first metatarsal

A case is described in which a 30% elongation of the first metatarsal was achieved by gradual distraction with a mini-Hoffman device. The procedure resulted in considerable cosmetic improvement.     

Shortening of the first metatarsal as a complication of metatarsal osteotomies

There have been few reports of shortening of the first ray of the foot because of damage to the physis of the first metatarsal during the performance of metatarsal osteotomy for residual metatarsus adductus. In a retrospective study of twenty-seven feet in twenty patients who underwent this procedure, eight feet in seven patients were noted to have some degree of residual shortening of the first ray. This is an incidence of 30 per cent. The follow-up period after osteotomy ranged from two years to seven years and four months (average, four years). We could find no clear correlation between the occurrence of shortening and the patient's age at osteotomy, sex, or race, or the etiology of the adduction for which the osteotomy had been done. A clear correlation was found, however, with the surgical technique that had been employed. In two of the eight feet with a short first ray, the osteotomy had been done within the physis of the first metatarsal. In the other feet the procedure had employed an osteotomy site close to the physis or extensive periosteal dissection, or both. The results in our patients implicate subperiosteal dissection of the first metatarsal as an important, previously unreported cause of damage to the physis and of the resultant shortening. We recommend radiographic determination of the relationship of the osteotomy site to the physis before dissection is performed.     

Unicameral bone cyst of the first metatarsal

An unusual case of a unicameral bone cyst located in the head of the first metatarsal is presented with a review of the literature. This benign bone tumor is rarely found in the metatarsal bones. Pathologic, clinical, and radiographic findings, as well as a differential diagnosis will be discussed.     

Influence of foot position on the measurement of first metatarsal axial rotation using the first metatarsal axial radiographs

BackgroundThe purpose of this study was to clarify 1) the measurement error of the pronation angle using the first metatarsal axial radiograph with the pronation angle along the longitudinal axis of the first metatarsal as the reference standard, 2) the influence of variability in the foot position on the measurement error, and 3) the intra- and interrater reliability of pronation angle measurement using digitally reconstructed radiographs.MethodsDigitally reconstructed radiographs of the first metatarsal were generated from the computed tomography images of 10 feet without hallux valgus (non-HV group) and 10 feet with hallux valgus (HV group). In total, 135 images were created at different degrees of supination, plantarflexion, and adduction from each foot to simulate the first metatarsal axial view. Then, the pronation angle of the first metatarsal was measured. The measurement error was determined using the mean error and 95% limits of agreement. Simple linear regression analysis was used to test the correlations of the measurement error with pronation, plantarflexion and adduction angles. The intra- and interrater reliability of measurement was assessed using the intraclass correlation coefficient and minimum detectable change values.ResultsThe mean measurement errors were 0.1° for both the non-HV and HV groups. There was no significant correlation of the measurement error with pronation, plantarflexion or adduction angles for both groups. Additionally, the intraclass correlation coefficients for the intra- and interrater reliability were more than 0.9 in both the non-HV and HV groups with the minimum detectable change values ranging from 0.7° to 1.4°.ConclusionThe measurement error of first metatarsal pronation using the axial view was clinically acceptable. The measurements were not influenced by the variability in foot position while obtaining the radiograph. The first metatarsal axial view could be used to quantify the first metatarsal coronal rotation.     

The obliquity of the first metatarsal base

BACKGROUND: The degree of obliquity of the base of the first metatarsal is thought to predispose to metatarsus primus varus deformity. Radiographs currently are used to interpret the obliquity of the proximal first metatarsal but are subject to error. A 'normal' obliquity of the first metatarsal base has not yet been established. METHODS: Direct measurements of 77 human first metatarsals were used to establish mean values for the proximal first metatarsal obliquity angle with respect to age, gender, and ethnicity in this sample population. The overall length of the first metatarsal and the width of the base were measured. The measured values were compared in relation to age, gender, and ethnicity of the specimens. RESULTS: The overall mean obliquity angle was 3.42 degrees (range, -3 to 8 degrees, SD 2.54). The mean obliquity angle in females was 3.67 degrees (range, -3 to 8 degrees, SD 2.91). The mean obliquity angle in males was 3.30 degrees (range, -2 to 7 degrees, SD 2.24). Mean base obliquity angle in the African-American specimens was 3.0 degrees (range, 3 to 7 degrees, SD 2.59), while the average first obliquity angle in the Caucasian specimens was 3.83 degrees (range, -2 to 8 degrees, SD 2.34). The obliquity of the first metatarsal base increased with age from a mean of 3.5 degrees in the youngest group to 5.13 degrees in the oldest. CONCLUSIONS: Exaggerated obliquity of the first metatarsal base is a proposed cause for metatarsus primus varus. No average values had been established for the proximal first metatarsal obliquity. These mean values are useful in determining if pathologic obliquity is present. In this study group, the mean medial obliquity angle was 3.42 degrees.     

Avascular necrosis of the first metatarsal head

Avascular necrosis of the first metatarsal head is uncommon. It is most often seen following a distal metatarsal osteotomy for hallux valgus. In this setting surgery has usually involved extensive periarticular dissection as well. Although many cases may be subclinical, in its most pronounced form it is a powerful cause of failure of bunion surgery. This article examines the underlying factor contributing to this problem as well as its long-term management.     

Haematogenous osteomyelitis of the first metatarsal sesamoid

Summary A rare case of haematogenous osteomyelitis of the sesamoid of the first metatarsophalangeal-joint visualized by a CT-scan have been presented. The characteristics of this disease have been stressed. When the diagnosis had been considered treatment should be surgical drainage with debridement of all infected tissues. Previous authors [2, 3, 9] recommend antibiotic treatment, but it was not given to this patient. There was total cure after three months.     

Distal first metatarsal chevron osteotomy

The distal chevron osteotomy is a popular, reliable, effective procedure for correcting hallux valgus deformity and bunions. The procedure has been refined to produce and maintain satisfactory correction and repair. Significant modifications to the original procedure include alteration of the bone cuts and more thoughtful soft tissue releases to improve correction of sesamoid positioning. The most significant improvement involves a change in the osteotomy plane and angle, combined with internal fixation to maintain the correction. Finally, the sharp edge of the superior medial corner of the metatarsal head, identified as a source of excess pressure in shoewear, can be removed and beveled to a smooth rounded surface.     

参与第1跖趾关节的籽骨软骨软化症

目的　探讨籽骨软骨软化症的病因、病理。方法　对经病理学明确诊断的４ 例籽骨退行性改变患者进行回顾性分析, 结合足部解剖及生物力学特点探讨病因及病理。结果　４ 例均因长期穿尖头高跟鞋,产生强制性拇外翻及跖趾关节过度背伸,这种不正常的力学载荷最终导致籽骨软骨软化。结论　籽骨软骨软化症主要病因可能来源于两种效应即“弓弦效应”和“高弓效应”。     

Principles of first metatarsal osteotomies.

Summarizing all the data while choosing the suitable procedure for hallux valgus deformity leads to classification of 3 main categories, which are based on the intermetatarsal angle (Table 1). Mild deformity has less than 15 degrees intermetatarsal angle, intermediate deformity has 15 degrees to 20 degrees intermetatarsal angle, and severe deformity has more than 20 degrees [table: see text] intermetatarsal angle. Every category may be divided further into low degree of DMAA (8 degrees) or high degree of DMAA (> 15 degrees). When choosing the correct procedure, the length of the first metatarsal has to be considered. In short first metatarsals, base angular osteotomies lead to further shortening of the metatarsal. Displacement osteotomies are preferred. In mild deformity, a distal osteotomy can be performed. If a mild deformity has a high DMAA, it can be corrected by a distal rotated chevron osteotomy. Intermediate deformity with a normal DMAA can be corrected by displacement osteotomies, and high DMAA can be corrected by rotated scarf of double osteotomy, which includes a base osteotomy to correct the intermetatarsal angle and a distal osteotomy, such as Riverdin, to correct the DMAA. Severe deformity can be corrected only by angular osteotomies. Inherently, these osteotomies increase the DMAA; they can be performed only in normal DMAA. Only a base angular osteotomy and distal rotation osteotomy can correct high levels of DMAA in severe intermetatarsal angles.     

Bilateral cleft epiphysis of the first metatarsophalangeal joint

We report the case of a young patient who presented with symptomatic bilateral cleft epiphyses of the first metatarsophalangeal joint. She has become asymptomatic with radiological union of the clefts after prolonged follow-up, but is left with moderate hallux rigidus. This condition was thought previously only to be a radiological variant, with no documentation of symptomatic presentation or radiological resolution of the cleft.