Abstract
Epiphysiodesis is performed to treat leg-length discrepancies and angular deformities in children. However, when placed across a physis to modulate growth, screws can bend or break postoperatively. This study evaluated the mechanical properties of 3 different screw designs commonly used when performing an epiphysiodesis. Six 4.0-mm cannulated, fully threaded; six 4.0-mm cannulated, partially threaded; and six 4.0-mm noncannulated, partially threaded cancellous screws underwent cantilever bending and tension testing in a simulated physis. All screws were tested in simulated cancellous bone foam blocks. All testing was performed using a servo-hydraulic testing machine to determine stiffness and ultimate load. For statistical analysis, one-way analysis of variance with Tukey's honestly significant difference test in post hoc analysis was used to assess significant differences among groups (P<.05). The noncannulated, partially threaded screws had a significantly lower stiffness than the 2 cannulated screw types in the tension test (P<.001) and bending test (P<.001). Additionally, the noncannulated, partially threaded screws had significantly higher ultimate load to failure than the 2 cannulated screw types in the tension test (P<.001) and the cannulated, partially threaded screws in the bending test (P=.045). The results indicate that noncannulated, partially threaded screws have a higher ultimate load capacity and are less stiff than both cannulated, partially threaded screws and cannulated, fully threaded screws. Surgeons should take into consideration that noncannulated, partially threaded screws are less likely to fail following epiphysiodesis. [Orthopedics. 2018; 41(2):e240–e244.]
- 1.Phemister DB. Operative arrestment of longitudinal growth of bones in the treatment of deformities. J Bone Joint Surg Am. 1933; 15:1–15. Google Scholar
- 2.Blount WP, Clarke GR. Control of bone growth by epiphyseal stapling: a preliminary report. J Bone Joint Surg Am. 1949; 31(3):464–478.
10.2106/00004623-194931030-00002 Crossref, Google Scholar - 3.Bowen JR, Johnson WJ. Percutaneous epiphysiodesis. Clin Orthop Relat Res. 1984; 190:170–173. Crossref, Google Scholar
- 4.Ilharreborde B, Gaumetou E, Souchet P, Efficacy and late complications of percutaneous epiphysiodesis with transphy-seal screws. J Bone Joint Surg Br. 2012; 94(2):270–275.
10.1302/0301-620X.94B2.27470 Crossref Medline, Google Scholar - 5.Nouth F, Kuo LA. Percutaneous epiphysiodesis using transphyseal screws (PETS): prospective case study and review. J Pediatr Orthop. 2004; 24(6):721–725.
10.1097/01241398-200411000-00023 Crossref Medline, Google Scholar - 6.Khoury JG, Tavares JO, McConnell S, Zeiders G, Sanders JO. Results of screw epiphysiodesis for the treatment of limb length discrepancy and angular deformity. J Pediatr Orthop. 2007; 27(6):623–628.
10.1097/BPO.0b013e318093f4f4 Crossref Medline, Google Scholar - 7.Driscoll MD, Linton J, Sullivan E, Scott A. Medial malleolar screw versus tension-band plate hemiepiphysiodesis for ankle valgus in the skeletally immature. J Pediatr Orthop. 2014; 34(4):441–446.
10.1097/BPO.0000000000000116 Crossref Medline, Google Scholar - 8.Podeszwa DA, Wilson PL, Holland AR, Copley LA. Comparison of bioabsorbable versus metallic implant fixation for physeal and epiphyseal fractures of the distal tibia. J Pediatr Orthop. 2008; 28(8):859–863.
10.1097/BPO.0b013e31818e19d7 Crossref Medline, Google Scholar - 9.Slone HS, Stacey SC, Mooney JF. Mechanical failure of single cannulated screw fixation of unstable slipped capital femoral epiphysis. J Pediatr Orthop B. 2014; 23(1):49–54.
10.1097/BPB.0b013e328364eb74 Crossref Medline, Google Scholar - 10.Stevens PM, Belle RM. Screw epiphysiodesis for ankle valgus. J Pediatr Orthop. 1997; 17(1):9–12.
10.1097/01241398-199701000-00003 Crossref Medline, Google Scholar - 11.Métaizeau JP, Wong-Chung J, Bertrand H, Pasquier P. Percutaneous epiphysiodesis using transphyseal screws (PETS). J Pediatr Orthop. 1998; 18(3):363–369.
10.1097/01241398-199805000-00018 Crossref Medline, Google Scholar - 12.Sánchez Mesa PA, Yamhure FH. Percutaneous hemi-epiphysiodesis using transphyseal cannulated screws for genu valgum in adolescents. J Child Orthop. 2009; 3(5):397–403.
10.1007/s11832-009-0203-8 Crossref Medline, Google Scholar - 13.Brown GA, McCarthy T, Bourgeault CA, Callahan DJ. Mechanical performance of standard and cannulated 4.0-mm cancellous bone screws. J Orthop Res. 2000; 18(2):307–312.
10.1002/jor.1100180220 Crossref Medline, Google Scholar - 14.Tencer AF, Asnis SE, Harrington RM, Chapman JR. Biomechanics of cannulated and noncannulated screws. In: , eds. Cannulated Screw Fixation: Principles and Operative Techniques. New York, NY: Springer-Verlag; 1996:15–40.
10.1007/978-1-4612-2326-9_2 Crossref, Google Scholar - 15.Leggon R, Lindsey RW, Doherty BJ, Alexander J, Noble P. The holding strength of cannulated screws compared with solid core screws in cortical and cancellous bone. J Orthop Trauma. 1993; 7(5):450–457.
10.1097/00005131-199310000-00008 Crossref Medline, Google Scholar - 16.Chapman JR, Harrington RM, Lee KM, Anderson PA, Tencer AF, Kowalski D. Factors affecting the pullout strength of cancellous bone screws. J Biomech Eng. 1996; 118(3):391–398.
10.1115/1.2796022 Crossref Medline, Google Scholar - 17.Thompson JD, Benjamin JB, Szivek JA. Pullout strengths of cannulated and noncannulated cancellous bone screws. Clin Orthop Relat Res. 1997; 341:241–249.
10.1097/00003086-199708000-00035 Crossref, Google Scholar - 18.Reese K, Litsky A, Kaeding C, Pedroza A, Shah N. Cannulated screw fixation of Jones fractures: a clinical and biomechanical study. Am J Sports Med. 2004; 32(7):1736–1742.
10.1177/0363546504264929 Crossref Medline, Google Scholar - 19.Yang SW, Kuo SM, Chang SJ, Biomechanical comparison of axial load between cannulated locking screws and noncannulated cortical locking screws. Orthopedics. 2013; 36(10):1316–1321.
10.3928/01477447-20130920-26 Link, Google Scholar - 20.Jacobson NA, Feierabend SP, Lee CL. Management of cannulated screw failure and recurrent SCFE displacement: case report. J Orthop Case Rep. 2014; 4(1):28–31.
10.13107/jocr.2250-0685.144 Crossref Medline, Google Scholar - 21.Slone HS, Stacey SC, Mooney JF. Mechanical failure of single cannulated screw fixation of unstable slipped capital femoral epiphysis. J Pediatr Orthop B. 2014; 23(1):49–54.
10.1097/BPB.0b013e328364eb74 Crossref Medline, Google Scholar - 22.Normandin BM, Tennent DJ, Baldini TH, Blanchard AM, Rhodes JT. Epiphysiodesis screw bending. Orthopedics. 2017; 40(4):e717–e720.
10.3928/01477447-20170308-08 Link, Google Scholar - 23.Elfar J, Menorca RM, Reed JD, Stanbury S. Composite bone models in orthopaedic surgery research and education. J Am Acad Orthop Surg. 2014; 22(2):111–120. Medline, Google Scholar
- 24.Bright RW, Burstein AH, Elmore SM. Epiphyseal-plate cartilage: a biomechanical and histological analysis of failure modes. J Bone Joint Surg Am. 1974; 56(4):688–703.
10.2106/00004623-197456040-00004 Crossref Medline, Google Scholar
