The Lapidus bunionectomy is a popular procedure for severe bunion deformity where metatarsus primus varus is equal to or exceeds 15 degrees. We evaluated a new locking compression plate which may improve outcomes with the Lapidus procedure.
Methods:
Ten matched pairs of cadaver feet were used to compare the standard crossed 4.0-mm compression screw method of fixation to the LPS Lapidus plate. After performing the matched operations the cadaver constructs were stressed to failure using the INSTRON and Wavemaker software.
Results:
The LPS Lapidus plate load to failure was 108 Nm with a bending moment of 6.0 Nm. The crossed screw technique was inferior at 78 Nm with a bending moment of 4.4 Nm (p = 0.02)
Conclusion:
Unlike other H-plates or locking plates, load to failure was higher with the Lapidus plate constructs.
Clinical Relevance:
The increased rigidity provided by these plates may help to minimize the risk of nonunion or malunion.
BednarzPAManoliA: Modified Lapidus Procedure for the Treatment of Hypermobile Hallux Valgus. Foot Ankle Int.
2.
BozkurtM: Stability of a Cannulated Screw vs. a Kirschner Wire for the Proximal Crescentic Osteotomy of the First Metatarsal: A Biomechanical StudyJ. Foot and Ankle Surg. 43:138–143, 2004. http://dx.doi.org/10.1053/j.jfas.2004.03.010.
3.
CarlARossSEvanskiPWaughT: Hypermobility in hallux Valgus. Foot ankle Int. 8:264–270, 1998.
4.
CatanzaritiAMendicinoRWLeeMSGallinaMR: The Modified Lapidus Arthrodesis: A Retrospective Analysis. J. Foot Ankle Surg. 38:322–332, 1999.
5.
ChowYCLuiTHKwokKWChowYY: Plate Fixation for Crescentic Metatarsal Osteotomy in the Treatment of Hallux Valgus: An Eight-Year Followup Study, Foot Ankle Int. 29: 29–33, 2008. http://dx.doi.org/10.3113/FAI.2008.0029.
6.
ClarkHRVeithRGHansenST: Adolescent Bunions Treated by the Modified Lapidus Procedure. Bull. Hosp. Joint Dis., 47:109–122, 1987.
7.
CoetzeeJCWickumD: The Lapidus Procedure: A Prospective Cohort Outcome Study. Foot Ankle Int. 25:526–531, 2004.
8.
CohenDAParksBGSchonLC: Screw Fixation Compared to H-Locking Plate Fixation for first Metatarsaocuneiform Arthrodesis: A Biomechanical Study, Foot Ankle Int. 26: 984–989, 2005.
GoldnerJLGainesRW: Adult and Juvenile Hallux Valgus: Analysis and Treatment. Orthop. Clin. N. Am. 7:863–887, 1976.
11.
HansenST: Functional Reconstruction of the foot and Ankle. Philadelphia, Lippincott Williams Wilkins, pg 221, 2000.
12.
HortonGAOlneyBW: Deformity Correction and Arthrodesis of the Midfoot With a Medial Plate. Foot ankle Int. 14:493–499, 1993.
13.
JohnsonKAKileTA: Hallux Valgus Due to Cuneiform Metatarsal Instability. J. South. Orthop. Assoc. 3:273–282, 1994.
14.
KomendaGAMyersonMSBiddingerKR: Results of arthrodesis for Management of Hallux Valgus and Metatarsus Primus Varus. J. bone Joint Surg. 78A:1665–1676, 1996.
15.
LapidusPW: The Operative correction of the Metatarsus Varus Primus in Hallux Valgus. Surg. Gynecol. Obstet. 58:183–191, 1934.
16.
LapidusPW: The Author's bunion Operation from 1931 to 1959. Clin. Orth. Rel. Res. 16:119–135, 1960.
17.
MannRAPriekskornDSobelM: Mid-tarsal and Tarsometatarsal Arthrodesis for Primary Degenerative Osteoarthritis or Osteoarthritis After Trauma. J. Bone Joint Surg., 78A:1376–1385, 1996.
18.
McInnesBDBoucheRT: Critical Evaluation of the Modified Lapidus Procedure. J. Foot Ankle Surg. 40:71–90, 2001.
19.
MyersonMAllonSMcGarveyW: Metatarso-cuneiform Arthrodesis for Management of Hallux Valgus and Metatarsus Primus Varus. Foot Ankle Int, 13:107–113, 1992.
ScrantonPEZuckermanJD: Bunion Surgery in Adolescents: Results of Surgical Treatment. J. Ped. Orthop., 4:39–43, 1984.
22.
ScrantonPE: “Principles in Bunion Surgery.”J. Bone Joint Surg. 65A:1026–28, 1983.
23.
ViennePFavrePMeyerD: Strength of Fixation of Ludloff Metatarsal Osteotomy Utilizing Three different Types of Kirschner Wires: a Biomechanical Study. Foot Ankle Int., 24:805–811, 2003.
24.
ViennePFavrePMeyerD: Comparative Mechanical Testing of Different Geometric Designs of Distal first Metatarsal Osteotomies. Foot Ankle Int. 28:232–236, 1997.
25.
WeilLZlotoffHJCoutureSD: Diagnosis and treatment of first metatarsophalangeal joint disorders. Section 3: Hallux varusJ Foot Ankle Surg Vol. 42(3), pp. 137–42, 2003.
