Biomechanics of the first ray. Part III. Consequences of Lapidus arthrodesis on peroneus longus function: a three-dimensional kinematic analysis in a cadaver model.
It has long been proposed that first metatarsocuneiform joint (FMCJ) arthrodesis, also known as Lapidus arthrodesis, can realign the first ray and permanently lock the FMCJ to control hypermobility. Left unanswered is the functional consequence of peroneus longus (PL) after such a procedure. In this study, the effects of PL on the medial column of the foot before and after metatarsocuneiform arthrodesis were evaluated. Seven fresh-frozen cadaver specimens with an intact foot and ankle were mounted on a custom-made acrylic frame and loaded to 400 N while midstance motor function was simulated with pneumatic actuators. Three-dimensional radiowave tracking transducers were attached to the first metatarsal, medial cuneiform, navicular, and talus to measure osseous movements while tensile loads of 0% to 100% of PL predicted force was applied. Simulated arthrodesis of the metatarsocuneiform joint and then additionally the intercuneiform 1-2 joint was achieved with titanium pins and then retested to determine any change in effect from PL. Significant frontal plane eversion of the medial cuneiform (p = .016) and dorsiflexion of the talus (p = .045) occurred after Lapidus arthrodesis was achieved. This suggests that arthrodesis at the first metatarsocuneiform joint increases the efficiency of PL stabilizing action on the medial column.
Bierman
R A
RA
Northwest Surgical Biomechanics Research Laboratory, Swedish Medical Center, Seattle, WA 98122, USA.
Christensen
J C
JC
Johnson
C H
CH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001174:Arthrodesis / Q000379:methods*; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D005529:Foot Bones / Q000502:physiology*; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D008297:Male; D008682:Metatarsal Bones / Q000502:physiology*; D008875:Middle Aged; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000502:physiology*; D013640:Tarsal Joints / Q000502:physiology / Q000601:surgery*