Re: Bipartite Tibial Sesamoid
THE FOLLOWING IS OFFERED GRATIS AS GENERAL INFORMATION ONLY, AND, AS SUCH, MAY NOT BE APPLICABLE TO THE SPECIFIC QUESTIONER AND/OR HIS/HER PROBLEM. IT IS CLEARLY NOT BASED ON ACTUAL KNOWLEDGE AND/OR EXAMINATION OF THE QUESTIONER OR HIS/HER MEDICAL HISTORY, AND IT CAN NOT AND SHOULD NOT BE RELIED UPON AS DEFINITIVE MEDICAL OPINION OR ADVICE. ONLY THROUGH HANDS-ON PHYSICAL CONTACT WITH THE ACTUAL PATIENT CAN ACCURATE MEDICAL DIAGNOSIS BE ESTABLISHED AND SPECIFIC ADVICE BE GIVEN. NO DOCTOR/PATIENT RELATIONSHIP IS CREATED OR ESTABLISHED OR MAY BE INFERRED. THE QUESTIONER AND/OR READER IS INSTRUCTED TO CONSULT HIS OR HER OWN DOCTOR BEFORE PROCEEDING WITH ANY SUGGESTIONS CONTAINED HEREIN, AND TO ACT ONLY UPON HIS/HER OWN DOCTOR’S ORDERS AND RECOMMENDATIONS. BY THE READING OF MY POSTING WHICH FOLLOWS, THE READER STIPULATES AND CONFIRMS THAT HE/SHE FULLY UNDERSTANDS THIS DISCLAIMER AND HOLDS HARMLESS THIS WRITER. IF THIS IS NOT FULLY AGREEABLE TO YOU, THE READER, AND/OR YOU HAVE NOT ATTAINED THE AGE OF 18 YEARS, YOU HEREBY ARE ADMONISHED TO READ NO FURTHER.
First, I need to review with you the function of the hallux sesamoids. By definition, a sesamoid bone is a naturally occurring bone which develops within a tendon, the ostensible purpose of which is to give greater mechanical advantage to the tendon in which it is invested as it crosses a joint. In the case of the hallux sesamoids, each is invested in the respective medal and lateral tendons of the flexor hallucis bresis muscle. The function of the flexor hallucis brevis muscle is not merely to assist the flexor hallucis longis in flexing the great toe at the first metatarsal-phalangeal joint, but its more important function is to stabilize the great toe during weight-bearing when the toe is DORSIflexed. In this function, it acts to give purchasing power to the great toe just prior to push-off. A cock-up or hammering of the great toe is possible, but more of a potential when BOTH tendons of the flexor hallucis brevis are disrupted, such as in a Keller bunionectomy where the base of the proximal phalanx is resected.
A tibial sesamoidectomy will invariably cause damage to the medial tendon of the flexor hallucis brevis, although skillful "shelling out" of the sesamoid from the tendon and subsequent skillful repair can minimize this. In addition, a tibial sesamoidectomy, both because of potential damage to the medial tendon of the flexor hallucis brevis and the surgical approach through the medial aspect of the joint capsule and portions of the hallucis abductus tendon, tends to present the possibility of subsequent hallux valgus, especially in patients who already have such tendency. All that being said, most surgical procedures are a trade-off between what IS and what hopefully will be BETTER, and the average patient does well both short and long term with a tibial sesamoidectomy, with the pain generally resolved, providing that the sesamoid was indeed the cause of the pain. Athletes whose sport depends greatly on foot function always present a special situation with any sort of foot surgery, and how much, if any, a sesamoidectomy will mitigated any individual athlete's ability to run at the level to which he/she sas accustomed is not qualitatively reliably predictable.
A bipartite sesamoid is a commonly occurring anomaly, probably cause by some abnormality in its development and/or ossefication. Most bipartite sesamoids are larger than would be a non-bipartite one, but, although on x-ray they appear to be unconnected bones, in reality, they are generally "fused" together by fibrocartilage, and personally, I would dispute the need and/or advisability to disrupt this fibrocartilage "fusion" for the purpose of a graft. Then again, in my experience, I have not found that bipartite sesamoids present any more propensity for sesamoiditis than non-bipartite sesamoids, and therefore it may be that fusing one may not resolve the sesamoiditis. Of course, it must be established that this so-called bipartite sesamoid is not really a non or mal-united fractured sesamoid, in which event a graft MIGHT be helpful.