Traumatic posterior dislocation of sacrococcygeal joint: A case report and review of the literature.

BACKGROUND: Sacrococcygeal joint dislocation is very rare. There are seven cases of sacrococcygeal joint dislocation found in the literature; most are anterior, and only one prior case of posterior dislocation was reported involving the mid-coccygeal joint. Here, we report another case of posterior dislocation of the sacrococcygeal joint. CASE DESCRIPTION: A 19 year-old female developed acute low-back and groin pain following a fall from the first floor. She was diagnosed with an unstable pelvic fracture along with posterior dislocation of the sacrococcygeal joint. The next day, after being hemodynamically stabilized, she underwent percutaneous fixation of the sacral fracture, while the sacrococcygeal joint dislocation was managed conservatively. Her pain decreased, and she was discharged on the third postoperative day and followed up to 6 weeks.
CONCLUSION: Most sacrococcygeal joint dislocations can be managed conservatively. Copyright:

INTRODUCTION

The sacrococcygeal symphysis is a fibrocartilaginous joint that connects the apex of the sacrum to the coccyx.[7,8] Sacrococcygeal joint dislocation is very rare and usually follows a direct fall onto buttocks. Two types of dislocations are described; the anterior dislocations are more common than the posterior ones; and they can lead to chronic pain. Treatment options include NSAIDS and physical therapy, steroid injections into the joint, coccyx manipulations, tension band fixation, surgical pinning together of the sacrum and coccyx, and coccygectomy. Seven cases of sacrococcygeal joint dislocation have been reported in the literature (e.g., six anterior and one posterior), to this we add another case of posterior dislocation of the sacrococcygeal joint.[2,3]

CASE DESCRIPTION

A 19-year-old female sustained a fall from the first floor of her home. She presented with acute lower back and groin pain. The pelvic X-rays [Figure 1a] showed fractures of the bilateral superior and inferior pubic rami, and a right sacral ala fracture with posterior sacrococcygeal dislocation. The lumbo-sacral-pelvic MRI and CT scans confirmed the sacrococcygeal dislocation [Figure 1b and c]. After being hemodynamically stabilized, surgery on the 2nd day of hospitalization included sacral fracture reduction and percutaneous fixation with two iliosacral screws. Notably, the sacrococcygeal dislocation was managed conservatively/nonsurgically. Postoperatively, the X-rays were satisfactory [Figure 2], and she was discharged on the 3rd postoperative day with minimal tenderness over the coccyx. Six weeks later, she was asymptomatic.

Figure 1:

(a) X-ray pelvis with both hip AP showing bilateral superior and inferior pubic rani fracture with Denis zone 2 fracture of sacrum (b) MRI mid-sagittal T2W image showing posterior sacrococcygeal joint dislocation. (c) CT mid-sagittal view showing posterior sacrococcygeal joint dislocation.

Figure 2:

Postoperative X-ray showing right sacroiliac joint percutaneous fixation and posterior dislocated sacrococcygeal joint.

DISCUSSION

Sacrococcygeal dislocation has no standard treatment guidelines. There are only isolated case reports that show the equal success of conservative[2,3,5,6] versus surgical[1,4] management [Table 1]. Kanabur et al.,[3] in 2017, published the case of a 13-year-old female with traumatic anterior sacrococcygeal joint dislocation treated with rectal closed manipulation; despite partial loss of alignment, she was asymptomatic at 36 postoperative months. Hamoud and Abbas,[2] in 2017, presented two cases of sacrococcygeal dislocation, both successfully managed conservatively.

Table 1:

Review of the literature.

Rijal et al.,[6] in 2004, published their case of a traumatic anterior dislocation of the coccyx after a fall; they attempted per-rectal closed reduction that was unsuccessful; although they recommended an open procedure, the patient refused, and 8 months later, which was asymptomatic. Kim et al.[4] reported in 2004 a 31-year-old female whose traumatic anterior sacrococcygeal dislocation was initially managed with manipulation under general anaesthesia; due to difficultly in maintaining the alignment, minimally invasive surgery using a joystick manoeuvre was employed to reduce the sacrococcygeal joint and stabilize it with a smooth 2.4 mm diameter Steinman pin.

Here, the authors concluded that fracture–dislocations of the coccyx in young adults could be effectively treated conservatively and avoided performing a closed reduction due to their high failure rates.[2]

CONCLUSION

In this case, a 19-year-old female underwent sacral fracture reduction with percutaneous placed double iliosacral screw fixation, while the sacrococcygeal posterior dislocation was managed conservatively.