Korean J Sports Med.  2021 Dec;39(4):193-197. 10.5763/kjsm.2021.39.4.193.

Atypical Spondylolysis of the Fifth Lumbar Vertebra in Baseball Players: Two Cases Report

• Cho HL
• Kim DY
• Jin HK
• Kim JH

• KMID: 2523235
• DOI: http://doi.org/10.5763/kjsm.2021.39.4.193

Abstract

Lumbar spondylolysis is a frequent cause of low back pain especially in adolescents involved in sporting activities. It is considered as a fatigue-type defect in the pars interarticularis or isthmus resulted from repetitive hyperextension and rotation on the spine; however, there is still confusion in regard to imaging findings of the location and direction of the defect. We report two unique cases of fifth lumbar spondylolysis in professional baseball hitter and adolescent pitcher; early-stage unilateral incomplete isthmus fracture and bilateral fracture in a different configuration, respectively. Computed tomography demonstrated vertical and more coronally oriented fracture lines compared with typical spondylolytic defect, and repetitive rotation in the same direction of pitching might cause a different type of fracture on the contralateral isthmus with the preexisting unilateral defect. Intriguingly, early-stage unilateral fracture in hitter was united after only 6 weeks of rest and rehabilitation and able to return to the game.

Keyword

Low back pain; Spondylolysis; Atypical; Stress fracture; Isthmus

Figure

• 

  Fig. 1 Fat-suppressed sagittal magnetic resonance imaging in case 1. (A) Compared to the normal right posterior elements, (B) high signal intensity bone marrow edema (arrow) in pedicle and superior articular process around low signal intensity vertical fracture line in the left isthmus of the fifth lumbar vertebra (L5). Inner boxes are scout images.

• 

  Fig. 2 Initial computed tomographic imaging in case 1. (A) Axial image of the fifth lumbar vertebra (L5) demonstrated linear fracture line (arrows) in anterior portion of the sclerotic isthmus. (B) Compared to the intact right isthmus in sagittal reconstructed image, (C) focal caudal cortical disruption (arrow) was located in ventral portion of the sclerotic isthmus (arrowhead). Inner boxes are scout images.

• 

  Fig. 3 Six-week follow-up computed tomographic imaging in case 1 showed complete healing of the previous left isthmic fracture (arrows) of the fifth lumbar vertebra (L5) on (A) axial and (B) sagittal reconstructed images. Inner boxes are scout images.

• 

  Fig. 4 Both oblique plain radiographs in case 2 showed (A) typical Scotty dog defect (arrows) in the right isthmus of the fifth lumbar vertebra (L5); however, (B) the left isthmus was relatively intact and oblique fracture line (arrows) was seen on anterior portion of the left inferior articular process of L5.

• 

  Fig. 5 Fat-suppressed sagittal magnetic resonance imaging in case 2. (A) Compared to typical high signal intensity right isthmic defect (arrow) of the fifth lumbar vertebra (L5), (B) high signal intensity bone marrow edema (arrowheads) in the left pedicle of the L5 anterior to low signal intensity fracture line (arrows). Inner boxes are scout images.

• 

  Fig. 6 Initial computed tomographic imaging in case 2. (A) Axial image of the fifth lumbar vertebra (L5) demonstrated horizontally directed left isthmic fracture line (arrowhead) compared to posterolaterally oriented right fracture line (arrows). (B) Compared to typical oblique dorsoventral right isthmic defect of the L5 (arrows) in sagittal reconstructed image, (C) coronally oriented vertical fracture line of left isthmus of L5 (arrows) was extended to upper facet joint. Inner boxes are scout images.

Reference

1. Haukipuro K, Keranen N, Koivisto E, Lindholm R, Norio R, Punto L. 1978; Familial occurrence of lumbar spondylolysis and spondylolisthesis. Clin Genet. 13:471–6. DOI: 10.1111/j.1399-0004.1978.tb01200.x. PMID: 668183.

2. Wiltse LL, Widell EH Jr, Jackson DW. 1975; Fatigue fracture: the basic lesion is inthmic spondylolisthesis. J Bone Joint Surg Am. 57:17–22. DOI: 10.2106/00004623-197557010-00003. PMID: 1123367.

3. Fredrickson BE, Baker D, McHolick WJ, Yuan HA, Lubicky JP. 1984; The natural history of spondylolysis and spondylolisthesis. J Bone Joint Surg Am. 66:699–707. DOI: 10.2106/00004623-198466050-00008. PMID: 6373773.

4. Tezuka F, Sairyo K, Sakai T, Dezawa A. 2017; Etiology of adult-onset stress fracture in the lumbar spine. Clin Spine Surg. 30:E233–8. DOI: 10.1097/BSD.0000000000000162. PMID: 28323705.

5. McCleary MD, Congeni JA. 2007; Current concepts in the diagnosis and treatment of spondylolysis in young athletes. Curr Sports Med Rep. 6:62–6. DOI: 10.1007/s11932-007-0014-y. PMID: 17212915.

6. Sairyo K, Katoh S, Sasa T, et al. 2005; Athletes with unilateral spondylolysis are at risk of stress fracture at the contralateral pedicle and pars interarticularis: a clinical and biomechanical study. Am J Sports Med. 33:583–90. DOI: 10.1177/0363546504269035. PMID: 15722292.

7. Conte SA, Thompson MM, Marks MA, Dines JS. 2012; Abdominal muscle strains in professional baseball: 1991-2010. Am J Sports Med. 40:650–6. DOI: 10.1177/0363546511433030. PMID: 22268233.

8. Yamashita K, Sakai T, Takata Y, et al. 2018; Utility of STIR-MRI in detecting the pain generator in asymmetric bilateral pars fracture: a report of 5 cases. Neurol Med Chir (Tokyo). 58:91–5. DOI: 10.2176/nmc.cr.2017-0123. PMID: 29276206. PMCID: PMC5830529.

9. Sairyo K, Katoh S, Komatsubara S, et al. 2004; Spondylolysis fracture angle in children and adolescents on CT indicates the facture producing force vector: a biomechanical rationale. Internet J Spine Surg. 1:1–6. DOI: 10.5580/15a.

10. Sakai T, Tezuka F, Yamashita K, et al. 2017; Conservative treatment for bony healing in pediatric lumbar spondylolysis. Spine (Phila Pa 1976). 42:E716–20. DOI: 10.1097/BRS.0000000000001931. PMID: 27755499.