Introduction and purpose: The expression hallux rigidus is used to describe a situation characterized by pain and a decrease in range of movement of the first metatarsophalangeal joint: the head of the first metatarsal moves on a sagittal plane without a stable surface, in spite of stabilizers such as the phalanx itself and the gleno-sesamoid system. The aim of this retrospective study is to define demographic data and their association with etiological, clinical and radiological factors in patients with primary hallux rigidus.

Materials and methods: We reviewed the records of one hundred and forty patients operated in our department between 1995 and 2005 for hallux rigidus. We selected 66 cases of primary hallux rigidus with complete clinical records. We excluded all secondary hallux rigidus cases from the study.

Results: We carried out comparative ANOVA studies to validate the relationship between weight and degree of hallux rigidus, as well as the relationship with BMI (body mass index), the value of the hallux valgus and distal hallux angle, the value of the adductor and the intermetatarsal angle. All these data were studied for a confidence interval of 95% and 90%. No statistically significant relationship was found, which does not mean that there may not be a relationship between parameters. Moreover, a direct relation was found between gender and development of hallux rigidus (p=0.095), which is statistically significant for a confidence interval of 90%. Height is also a parameter related to hallux rigidus, the greater the height of the patient the greater the development of hallux rigidus (p=0.067) for a 90% confidence interval. A radiological parameter statistically related to hallux rigidus is the elevation of the first metatarsal (p=0.075) for a confidence interval of 90%.

Conclusions:

Female sex and a greater frequency of hallux rigidus have a statistically significant relationship (p=0.095) for a 90% confidence interval. This is contrary to the opinion expressed in most of the literature published up to the present.

Joint replacement failure is usually caused by the formation of wear debris resulting in aseptic loosening. Particulate metal and soluble metal ions from orthopaedic alloys (cobalt chromium or vanadium titanium aluminium) that are used in medical prostheses can accumulate in tissues and blood leading to increased chromosome aberrations in bone marrow and peripheral blood lymphocytes. This paper demonstrates that two of the metals used in orthopaedic prostheses, chromium and vanadium can produce delayed as well as immediate effects on the chromosomes of human fibroblasts in vitro. Fibroblasts were exposed to metal ions for only 24 hours and were then expanded over 30 population doublings involving ten passages. The initial increase of chromosomal aberrations, micronuclei formation and cell loss due to lethal mutations persisted over multiple population doublings, thereby demonstrating genomic instability. Differences were seen in the reactions of normal human fibroblasts and those infected with a retrovirus carrying the cDNA encoding hTERT that rendered the normal human fibroblasts telomerase-positive and replicatively immortal. This suggests that chromosomal instability caused by metal ions is influenced by telomere length or telomerase activity. Formerly this syndrome of genomic instability has been demonstrated in two forms following irradiation. One type is non-clonal and involves the appearance of lethal aberrations that cannot have been carried by the surviving cells. The other type is clonal and the aberrations are not lethal. These may arise as a result of complex rearrangements occurring at a high rate post-insult in surviving cells. The consequences of genomic instability are not yet known but it is possible that the increase of chromosomal aberrations that have been previously observed in human patients could be due to immediate and delayed expression of cellular damage after exposure to orthopaedic metals.