Unilateral Lumbosacral Dislocation: Case Report and a Comprehensive Review

Theodoros B Grivas1, Stamatios A Papadakis*, 1, Vassiliki Katsiva2, George Koufopoulos1, Vassilios Mouzakis1
1 Orthopaedic Department, “Thriasio” General Hospital, G. Gennimata Av. 19600, Magoula, Attica, Greece
2 Department of Radiology, “Thriasio” General Hospital, G. Gennimata Av. 19600, Magoula, Attica, Greece

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 3290
Abstract HTML Views: 939
PDF Downloads: 316
Total Views/Downloads: 4545
Unique Statistics:

Full-Text HTML Views: 855
Abstract HTML Views: 532
PDF Downloads: 193
Total Views/Downloads: 1580

Creative Commons License
© Grivas et al.; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the 28th Octovriou Street 54, 15236 N. Pendeli, Greece; Tel: + 30 694 429 7086; Fax: +30 210 61 37 145; E-mail:


Lumbosacral fracture-dislocation is a rare occurrence. There are more than 73 cases reported in the English literature. We report on the imaging findings and surgical treatment in a patient suffered of unilateral traumatic L5-S1 dislocation associated with severe disruption of the posterior ligamentous complex. The patient underwent open reduction and stabilization of L4-S1 vertebrae with posterior instrumentation system. Open reduction and internal fixation was mandatory as post-traumatic ligamentous insufficiency would lead to abnormal motion. Operative treatment managed to produce a solid arthrodesis and restore stability of the lumbosacral junction. Follow-up revealed excellent results. This study reports a rare injury of the lumbosacral junction, and the literature concerning this unusual condition is extensively reviewed.

Keywords:: Unilateral lumbosacral dislocation, surgery, case report, review.


Unilateral facet dislocation is an injury classically localized to the mobile cervical spine [1]. However, its rarity in the lumbosacral spine is attributed to the orientation of the lumbar facet joints and the presence of robust muscular and capsuloligamentous structures that provide substantial stability in the lower lumbar region [2, 3].

Diagnosis of lumbosacral dislocation depends on an initial imaging study of good quality that demonstrates the abnormal relation of the lumbosacral facets [1]. Radiographs performed in the emergency room may hardly demonstrate subtle findings. The anteroposterior projection might show fractures of the ipsilateral lumbar transverse processes, lower lumbar scoliosis or signs of rotational malalignment at the lumbosacral junction including, widening of the interpedicular distance, rotational deformity of the spinous processes or increased interspinous distance. The lateral view may show an increased interspinous distance, a sharp kyphosis of L5 on S1, with anterior narrowing of the height of the disc space, malalignment of the facet joints or minimal anterior or posterior subluxation of L5 on S1 [4]. Computed tomography shows easily associated fractures [5-7]. The “naked facet” sign on the axial plane is indicative of facet dislocation. MRI examination allows identification of the herniated disc and degree of ligamentous disruption [8].

We report a case of unilateral traumatic L5-S1 dislocation, and the literature concerning this unusual condition is comprehensively reviewed.


An 18-year-old male was involved in a motorcycle accident, suffering an injury of the lumbar spine and a fracture of his left humerus. On admission the patient was confused, but awake and without history of loss of consciousness. Physical examination revealed abrasions to the patient’s left upper extremity. He complained of mild lumbosacral pain. Palpation of the spine revealed low lumbar tenderness with an echymosis in the lumbosacral region. There were no open wounds.

Neurological examination showed a 4+/5 muscular weakness in the left L5 root distribution. Rectal examination and perianal sensation were normal. Sensory examination revealed a decreased sensation in the lateral and plantar aspects of the left lower extremity. Hemodynamic and respiratory functions were normal.

Radiographic study:

Initial lumbosacral anteroposterior radiograph showed avulsion of the L5 left transverse process and obliquity of the lumbar spine on the sacrum, manifest as increase of the L5-S1 interspinous distance and as rotational deformity of the L5 spinous process (Fig. 1). Helical CT scan of the lumbosacral junction was performed using 3 mm axial slices from L4 to S1 level with reconstruction in the coronal and sagittal planes. This revealed unilateral left L5-S1 facet joint dislocation with perch of the articular facets and fracture of the L5 inferior process (the inferior part of it). On the right, fracture of the S1 superior articular facet was demonstrated with normal alignment of the facet joint (Figs. 2, 3a, b). Magnetic resonance imaging (MRI) of the lumbosacral spine confirmed the bone injuries and showed mild posterior subluxation of L5 on S1. Furthermore, it demonstrated disruption of the posterior ligamentous complex including the ligamentum flavum bilaterally, the interspinous and supraspinous ligaments and extensive high-signal intensity traumatic changes of the paraspinous musculature (Fig. 4). Epidural hematomas were noted causing compression of the dural sac. There was no evidence of disc disruption.

Fig. (1).

Preoperative anteroposterior radiograph. The L5-S1interspinous distance is increased and the interspinous line shows a stepoff at this level. Avulsion of the L5 left transverse process is identified (arrow). The left facet joint is not well delineated.

Fig. (2).

Axial CT image shows avulsion of the L5 left transverse process and the lateral half of the pedicle.

Fig. (3).

(a, b) CT oblique coronal reformatted sequential images demonstrate the fracture at the root of right superior facet (RS) (arrow), the normal right inferior facet (RI), the normal (not fractured) LS, the fractured left transverse process (TP). The inferior part of LI is not identified (comminuted).

Fig. (4).

MRI of the lumbosacral spine. Sagittal T2-weighted midline and off-midline images showing epidural haematoma (curved arrow), extensive high-signal intensity changes in the posterior ligamentous complex (empty arrow) and discontinuity of the ligamentum flavum (straight arrow) suggestive of disruption. Notice mild posterior subluxation of L5 on S1.

The patient underwent surgery the next day through a posterior approach. Intra-operative findings of unilateral facet fracture-dislocation were revealed. The left articular capsule of L5-S1 was torn. A rotational deformity of the L5 in relation to the sacrum was noticed. Disruption of the posterior ligamentous complex was evident and confirmed the imaging findings. Vertical traction force on the spinous process of L5 vertebra by using a small periosteal elevator could not managed to restore the reduction, as the inferior process of the L5 vertebra was comminuted and thus, unable to serve as a block against deforming forces. An arthrodesis was performed from L4 to S1 vertebrae using titanium rods and screws. This solution seemed to be appropriate as it could reduce the L5 displacement by applying traction to the right pedicle screw positioned in L5 with bent rods placed between L4 and S1. It was unable to insert a screw at the L5 left pedicle because it was fractured, (Fig. 5a, b).

Fig. (5).

Anteroposterior (a) and lateral (b) postoperative radiographs.

The patient was upright on the second postoperative day after bracing. Currently, seventy-two months after the injury, the patient is free of symptoms and able to walk without any help.


Traumatic fracture-dislocation of L5 is a very uncommon injury. It can be easily missed, especially in multi trauma patients [9]. The lumbosacral joint is a solid and stable junction and that because of its increased inclination in the sagittal plane, the more vertical orientation of the facets and the presence of the powerful musculature and the ligamentum complexes [10]. Rupture of the iliolumbar ligamentum complex increase the flexion at the lumbosacral joint by 77%, as experimentally demonstrated by Leong et al [11].

An in depth review of the literature revealed that 57 of patients were men (78%) and 16 were women (22%) [12-52]. The average age was 27 years and this injury pattern has been described in patients as young as 5 years [13] to as old as 52 years [5, 23]. The causes of the injury were motor vehicle accidents in 34 cases (46.5%), falls from a height in 17 cases (23.3%), occupational injuries in 13 cases (17.8%), motor versus pedestrian in 3 cases (4.1%), sports related injuries in 3 cases (4.1%), 2 cases after an airplane (1.4%) and a helicopter crash (1.4%), respectively, and one case was a war related injury (1.4%). Fractures of the transverse processes were seen in 34 cases (46.5%) [1, 2, 4-6, 8, 10, 12, 13, 15, 17, 18, 21, 23, 24, 28, 31, 37, 38-43, 47, 49, 50, 52], and disk involvement at L5-S1 level was present in 12 cases (16.4%) [1, 4, 10, 19, 28, 30, 32, 35, 45, 49]. The ratio bilateral/unilateral fracture-dislocations were 1.1:1. Additional injuries in the other parts of the body included head injuries, abdominal injuries, femur fractures, clavicular fractures, and rib fractures.

Thirty-six patients (58%) had a neurological deficit at time of their admission. Twenty-six patients were presented with no neurological compromise [1-5, 15, 20, 21, 23, 31, 33, 36-38, 43, 44, 47-50] and no data has been given for the rest 11 patients [8, 17, 20, 23, 27], regarding neurological involvement. The occurrence of neuropathological complications is broadly similar. They include paraplegia (or paraparesis) [29, 43, 43], lumbar plexus lesions, hyposthesia or anesthesia in the lower extremities, and urine retention. The vast majority of the patients are complaining of severe low back pain. However, severe disability is unusual.

Forced hyperextension was the first proposed responsible mechanism for this type of injury [53]. However, most authors recently agree that these types of injuries are provoked from severe forces applied to the lumbar spine, shifting it forward on the immovable sacrum, while the lumbar spine and hips are flexed [13, 23, 24, 26, 48, 52]. The presence of a presumed rotary component in the above mentioned mechanism leads to a dislocation as demonstrated in a cadaveric experimental study by Roaf [54].

Good quality initial radiographs are important for the diagnosis, as emergency room radiographs are frequently inadequate. Transverse processes fractures are a frequent radiologic sign [4, 10]. CT scan and MRI imaging studies are of great help and easily reveal associated fractures, soft tissue and disc disruptions as well as secondary spondylolysthesis.

Aihara et al, proposed a classification system by reviewing 57 cases [9]. They classified the injury into five types: type 1, unilateral lumbosacral facet-dislocation with or without facet fracture; type 2, bilateral lumbosacral facet-dislocation with or without facet fracture; type 3, unilateral lumbosacral facet-dislocation and contralateral lumbosacral facet fracture; type 4, dislocation of the body of L5 with bilateral fracture of the pars interarticularis; and type 5, dislocation of the body of L5 with fracture of the body and/or pedicle, with or without injury of the lamina and/or facet. The presented injury was judged to be type 3 as unilateral lumbosacral facet dislocation and contralateral lumbosacral facet fracture were present.

Despite the type of injury, fracture-dislocation of the lumbosacral junction is a three-column injury. Thus, the choice of the type of treatment is essential. Although reported success with conservative treatment has been published [2, 3, 14, 16, 21, 23, 26, 38, 40, 50], currently, this choice of treatment is not accepted. Open reduction internal fixation and bone grafting is postulated by many authors [18, 34, 37, 49] and pedicle screw instrumentation is the preferred method of choice [8, 17, 20]. Surgical intervention will ensure normal anatomical relationships, and late detoriation prevention. Aihara et al. [9], recommended anterior lumbar interbody fusion after posterior reduction of the dislocation with pedicle screw instrumentation. The prognosis varies from complete recovery to unchanged neurological involvement depending on the initial injury pattern presentation, as this comprehensive review revealed. Only one case has been reported that resulted to death due to extensive fat embolism after the operation [26].

In conclusion, this study reports a rare injury of the lumbosacral junction. Open reduction and internal fixation was mandatory, as post-traumatic ligamentous insufficiency would lead to abnormal motion. Operative treatment managed to restore the stability of the lumbosacral junction and to produce a solid arthrodesis and a good outcome after two years follow-up.


The authors confirm that this article content has no conflict of interest.


Declared none.


[1] Tsirikos A, Saifuddin A, Noordeen MH, Tucker SK. Traumatic lumbosacral dislocation: report of two cases Spine 2004; 29: E164-8.
[2] Zoltan JD, Gilula LA, Murphy WA. Unilateral facet dislocation between the fifth lumbar and first sacral vertebrae J Bone Joint Surg 1979; 61A: 767-9.
[3] Kramer KM, Levine AM. Unilateral facet dislocation of the lumbosacral junction J Bone Joint Surg 1989; 71A: 1258-61.
[4] Shen FH, Crowl A, Shuler TE, Feldenzer JA, Leivy SW. Delayed recognition of lumbosacral fracture dislocation in the multitrauma patient, the triad of transverse process fractures unilateral renal contusion and lumbosacral fracture dislocation J Orthop Trauma 2004; 56: 700-5.
[5] Vialle R, Wolff S, Pauthier F, et al. Traumatic lumbosacral dislocation: four cases and review of literature Clin Orthop 2004; 419: 91-7.
[6] Bents RT, France JC, Glover JM, Kaylor KL. Traumatic spondylopelvic dissociation Spine 1996; 21: 1814-9.
[7] Van Savage JG, Dahners LE, Renner JB, Baker CC. Fracturedislocation of the lumbosacral spine J Trauma 1992; 33: 779-84.
[8] Fabris D, Costantini S, Nena U, Lo Scalzo V. Traumatic L5-S1 spondylolisthesis: report of three cases and a review of the literature Eur Spine J 1999; 8: 290-5.
[9] Aihara T, Takahashi K, Yamagata M, Moriya H. Fracture dislocation of the fifth lumbar vertebra J Bone Joint Surg 1998; 80B: 840-5.
[10] Tohme-Noun C, Rillardon L, Krainik A, Guigui P, Menu Y, Feydy A. Imaging features of traumatic dislocation of the lumbosacral joint associated with disc herniation Skeletal Radiol 2003; 32: 360-.
[11] Leong JCY, Luk KDK, Chow DHK, Woo CW. The biomechanical functions of the iliolumbar ligament in maintaining stability of the lumbosacral junction Spine 1987; 12: 69-74.
[12] Barquet A, Menendez J, Dubra A, Masliah R, Pereyra D. Anterolateral dislocation of the lumbosacral junction Can Assoc Radiol J 1993; 44: 129-32.
[13] Beguiristain J, Schweitzer D, Mora G, Pombo V. Traumatic lumbosacral dislocation in a 5-year old boy with eight year followup Spine 1995; 20: 362-6.
[14] Boger DC, Chandler RW, Pearce JG, Balciunas A. Unilateral facet dislocation at the lumbosacral junction J Bone Joint Surg 1983; 65A: 1174-8.
[15] Boldin C, Grechenig W, Fankhauser F, Sorantin E. Traumatic unilateral facet dislocation of the lumbosacral junction Injury 2004; 35: 950-2.
[16] Boyd MC, Yu WY. Closed reduction of lumbosacral fracture dislocations Surg Neurol 1985; 23: 295-8.
[17] Carl A, Blair B. Unilateral lumbosacral facet fracture-dislocation Spine 1991; 16: 218-.
[18] Carlson J, Heller J, Mansfield F, Pedlow FX. Traumatic open anterior lumbosacral fracture dislocation: a report of two cases Spine 1999; 24: 184-8.
[19] Cohn SL, Keppler L, Akbarnia BA. Traumatic retrolisthesis of the lumbosacral junction Spine 1989; 14: 132-4.
[20] Connolly PJ, Esses SI, Heggeness MH, Cook SS. Unilateral facet dislocation of the lumbosacral junction Spine 1992; 17: 1244-8.
[21] Cruz-Conde R, Rayo A, Rodriguez de Oya R, Berjano P, Garate E. Acute traumatic lumbasacral dislocation treated by open reduction internal fixation and fusion Spine 2003; 28: E51-3.
[22] Daffner RH. Case report 570 Skeletal Radiol 1989; 18: 489-90.
[23] Das De S, McCreath SW. Lumbosacral fracture-dislocations J Bone Joint Surg 1981; 63B: 58-60.
[24] Davis AA, Carragee EJ. Bilateral facet dislocation at the lumbosacral joint Spine 1993; 18: 2540-4.
[25] Delplace J, Tricoit M, Sillion D, Vialla JF. Traumatic posterior dislocation of the lumbo-sacral joint Rev Chir Orthop 1983; 69: 141-5.
[26] Dewey P, Browne PSH. Fracture-dislocation of the lumbosacral spine with cauda equina lesion J Bone Joint Surg 1968; 50B: 635-8.
[27] Ebraheim NA, Savolaine ER, Shapiro P, Houston T, Jackson WT. Unilateral lumbosacral facet joint dislocation associated with vertical shear sacral fracture J Orthop Ttrauma 1991; 5: 498-503.
[28] Fardon DF. Displaced fracture of the lumbosacral spine with delayed cauda equina deficit Clin Othop 1976; 120: 155-8.
[29] Finkelstein JA, Hu RW, Al-Harby T. Open posterior dislocation of the lumbosacral junction Spine 1996; 21: 378-80.
[30] Griffin JB, Sutherland GH. Traumatic posterior fracture-dislocation of the lumbosacral joint J Trauma 1980; 20: 426-8.
[31] Guillamon JL, Samuel P. Complete lumbosacral dislocation Rev Chir Orthop 1985; 72: 269-74.
[32] Hodges SD, Shuster J, Asher MA, McClarty SJ. Traumatic L5-S1 spondylolisthesis South Med J 1999; 92: 316-20.
[33] Herron LD, Williams RC. Fracture-dislocation of the lumbosacral spine Clin Orthop 1984; 186: 205-11.
[34] Jackson RH, Quisling RG, Day AL. Fracture and complete dislocation of the thoracic or lumbosacral spine: report of three cases Neurosurgery 1979; 5: 250-3.
[35] Kaplan SS, Wright NM, Yundt KD, Lauryssen C. Adjacent fracture-dislocations of the lumbosacral spine Neurosurgery 1999; 44: 1134-7.
[36] Miz GS, Engler GL. Unilateral dislocation of a lumbosacral facet Spine 1988; 13: 956-7.
[37] Morris BDA. Unilateral dislocation of a lumbosacral facet J Bone Joint Surg 1981; 63A: 164-5.
[38] Nagi ON, Dhillon MS, Gill SS. Bilateral fracture dislocation of the sacrum without injury to the anterior pelvis Orhtopedics 1993; 16: 215-7.
[39] Naude R, Govender S, Preston M. Fracture dislocation of the lumbosacral spine S Afr Med J 1992; 82: 486-7.
[40] Newell RL. Lumbosacral fracture-dislocation: a case managed conservatively with return to heavy work Injury 1977; 9: 131-4.
[41] Nicolson RA. Lateral lumbosacral fracture dislocation: a case report Injury 1983; 15: 41-3.
[42] Pellise F, Bago J, Villanueva C. Double level spinal injury resulting in “en bloc” dislocation of the lumbar spine. A case report Acta Orthop Belgica 1992; 58: 349-52.
[43] Stuart RM, Song SJ. Unilateral lumbosacral facet joint dislocation without associated fracture Australas Radiol 2004; 48: 224-9.
[44] Resnik C, Scheer C, Adelaar R. Lumbosacral dislocation Can Assoc Radiol J 1985; 36: 259-61.
[45] Roche PH, Dufour H, Graziani N, Jolivert J, Grisoli F. Anterior lumbosacral dislocation Surg Neurol 1998; 50: 11-6.
[46] Reinhold M, Knop C, Blauth M. Acute traumatic L5-S1 spondylolisthesis Arch Orthop Trauma Surg 2005; 126: 624-30.
[47] Roy-Camille R, Gagnon P, Catonne Y, Benazet JP. Anterolateral dislocation of the lumbo-sacral spine Rev Chir Orthop 1980; 66: 105-9.
[48] Samberg LC. Fracture-dislocation of the lumbosacral spine J Bone Joint Surg 1975; 57A: 1007-8.
[49] Steinitz DK, Alexander DI, Leighton RK, O’Sullivan JJ. Late displacement of a fracture dislocation at the lumbosacral junction Spine 1997; 22: 1024-7.
[50] Veras del Monte LM, Bago J. Traumatic lumbosacral dislocation Spine 2000; 25: 756-60.
[51] Verlaan JJ, Oner FC, Dhert WJA, Verbout AJ. Traumatic lumbosacral dislocation: case report Spine 2001; 26: 1942-4.
[52] Wilchinsky ME. Traumatic lumbosacral dislocation Orthopedics 1987; 10: 1271-4.
[53] Watson-Jones R. Fractures and joint injuries. 1st ed. Baltimore: Williams & Wilkins 1940.
[54] Roaf R. A study of the mechanics of spinal injuries J Bone Joint Surg 1960; 42B: 810-23.