358

CASE REPORT
Surgical Treatment of Lumbar Herniated Nucleus Pulposus
Combined with Residual Bony Fragment of Apophyseal Ring
Fracture in High-Level Athletes : A Report of Two Cases
Yuto Sugimine1, Kentaro Sakaeda2, Kazuta Yamashita1, Hiroaki Manabe1, Kosuke Sugiura1, Fumio Hayashi1,
Yoshihiro Ishihama1, Yoichiro Takata1, Toshinori Sakai1, Toru Maeda1, Tomohiko Tateishi2, and Koichi Sairyo1
Department of Orthopedics, Tokushima University Graduate School, Tokushima, Japan, 2Department of Orthopedic Surgery, Doai MemorialHospital, Tokyo, Japan1

Abstract : In this paper, we present 2 cases of herniated nucleus pulposus (HNP) combined with the residual
bony fragment of apophyseal ring fracture. HNP typically exists at the narrow lateral recess formed by the bony
fragment, and so it has been reported that symptoms may persist. Case 1 was a 22-year-old man, a high-leveljavelin thrower and Paralympic athlete. He had a history of persistent pain for 4 years due to HNP, and so we
performed surgical removal. Case 2 was a 23-year-old male professional baseball player. He was referred to usonly 17 days after the onset of pain and presented with muscle weakness, a feature which may prolong the clinical course in addition other features such as pain. Thus, we performed a comparatively quick intervention ofsurgical removal. In both cases, we had excellent clinical outcomes and better function and performance. In
conclusion, in cases with HNP and apophyseal ring separation, surgical intervention in the comparatively earlyphase can be recommended, particularly if the patients desire quick return to their original level of activity. J.
Med. Invest. 66 : 358-361, August, 2019
Keywords : High-level athlete, herniated nucleus pulposus, lumbar spine, apophyseal ring fracture

INTRODUCTION
Lumbar apophyseal ring fracture is an avulsion fractureof the posterior apophyseal vertebral endplate. This fracture
occurs more commonly in children and adolescents (1-3). Finite element analysis using skeletally immature spine models
suggested that the fracture basically appears in the immature spine due to mechanical weakness of the growth plateadjoining the apophyseal body ring (4,5). Generally, patientsare treated with conservative management (1) ; however, theclinical features tend to be prolonged and the patient could
eventually require surgical intervention to remove the bony
fragment (2). Even though conservative treatment would be
effective to reduce pain, the residual bony fragment may cause
spinal canal stenosis (1) or tightness of the hamstrings (6).
Akhaddar et al. (7) reported that posterior ring apophyseal
separation was diagnosed in 87 (5.35%) of 1625 adult patients
surgically treated for lumbar disc herniation. Since the separation typically occurs in children and adolescents, the residual bony fragment of the apophyseal fracture would likely bepresent.
In this paper, we presented two adult cases of herniated nucleus pulposus (HNP) associated with the residual bony fragment of apophyseal ring fracture in top athletes, and discuss
the management of high-level adult athletes with this comorbidcondition.

Received for publication February 18, 2019 ; accepted July 25, 2019.
Address correspondence and reprint requests to Kazuta Yamashita,MD, PhD, Associate Professor, Department of Orthopedics, Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima,Tokushima, 770-8503, Japan and Fax : +81-886-33-0178.

CASE REPORTS
Case 1

A 22-year-old man who was a javelin thrower noticed low backpain and left buttock pain whenever he practiced shot put or javelin throwing about 4 years prior to presentation. He underwent
conservative treatment at an outpatient clinic, but his symptoms
recurred several times. He was referred to our department for
further examination and treatment 4 years after the onset ofsymptoms. Past medical history was total blindness due to Leber’s hereditary optic neuropathy at age 15 years.
On physical examination at our clinic, there was no muscle
weakness or sensory disturbance. Straight leg raising test(SLRT) was negative at 80 degrees on both sides but femoral
nerve stretch test and Kemp’s sign were positive on the left.
There was tenderness in the lower back and posterior aspectof the left thigh. Plain radiography suggested a small bony
fragment at the posterior aspect of L4 vertebra, but this was
not clear. Magnetic resonance imaging (MRI) revealed lumbar
disc herniation (Fig 1). To further evaluate the bony lesion, weperformed computed tomography (CT) scanning. CT clearly
revealed a residual bony fragment of apophyseal ring fracture
at the upper endplate of L4 vertebrae (Fig 1). He was then diagnosed as having lumbar disc herniation at L3/4 with the osseous
remnant of the apophyseal ring fracture at L4.
Because he had been having symptoms for about 4 years, wedecided on surgical intervention. We performed micro endoscopic
discectomy (MED) and impacted the bony fragment with a bone
impactor for reduction (Fig 2). We started conditioning training
including lower leg stretching after the surgery. Left thigh painand numbness had improved in about 2 weeks. After a month,
he was allowed to practice throwing and instructed to continue
stretching because of tightness of the hamstrings. He returned
to competitive sport 3 months after surgery. Presently, 3 years
after the surgery, he has been a candidate Paralympic athlete.

The Journal of Medical Investigation Vol. 66 2019

The Journal of Medical Investigation Vol. 66 August 2019359

Figure 1

Case 1 : Plain radiograph and CT images reveal osseous remnant of apophyseal ring fracture of upper endplateof L4 vertebrae (arrows, a : plane lateral radiograph, b : CT scan sagittal view, c : CT scan axial view).
MRI T2WI shows lumbar disc herniation and left lateral recess stenosis at L3/4 (d : sagittal view, e : axial view).
CT myelograms also show lateral recess stenosis at L3/4 (f : sagittal view, g : axial view).

Case 2

Figure 2

Case 1 : Postoperative bony fragment reduction (a : CT scan sagittalview, b : CT scan axial view)
MRI T2WI shows that lumbar disc herniation was almost removed
and stenosis was resolved (c : sagittal view, d : axial view).

A 23-year-old male professional baseball player felt sudden
pain in the right leg. He had previously had low back pain during
middle school. MRI revealed lumbar disc herniation at L4/5 andL5/S. The pain worsened over time despite rest and conservative
treatment. He developed buttock pain, which together with theleg pain became so severe that he could not sleep well. By 17 days
after the initial episode, he was referred to our department for
further examination and possible surgery.
On physical examination, manual muscle test showed grade 4
weakness of the flexor hallucis longus (FHL) bilaterally. SLRT
was positive at 30 degrees on the right side. Hamstring tightness
was observed on both sides. Achilles reflex was hypoactive on theright. MRI revealed lumbar disc bulge at L4/5 and herniation atL5/S. Further CT scan was performed to detect osseous disorderand clearly revealed the osseous remnant of apophyseal ringfracture at S1. These radiologic findings are shown in Fig 3. The
duration of the presenting symptoms was about 3 weeks, and so
we decided to proceed with surgical intervention. The main reason for this decision was the presence of the residual bony fragment of the apophyseal ring fracture, which caused narrowing of
the lateral recess. This may in turn prolong the clinical course.
We performed transforaminal full endoscopic lumbar discectomy (TELD) at L4/5 under local anesthesia, followed by MED
at L5/S with bony fragment reduction using a bone impactor
under general anesthesia. The procedure was successful with nosurgery-related complications such as dural tear or nerve root
injury. Immediately after surgery, his symptoms subsided dramatically. Before surgery, SLRT was positive at 30 degrees on
the right side ; however, it improved to negative at 60 degrees on
the right side after surgery. After surgery, FHL weakness also
improved on both sides.
Fig 4 shows the radiologic findings after surgery. The bony

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Y. Sugimine, et al. Bony fragment of apophyseal ring fracture

fragment is seen to overhang the spinal canal (a, b) ; however, thefragment was snapped off when it was impacted to avoid pressure on the cauda equine and the nerve root. MRI T2 weighted
imaging (T2WI) shows that the lumbar disc herniation is almost

completely removed and stenosis is resolved at both L4/5 andL5/s (c, d).
Stretching of the tight hamstrings was performed using anactive stretching machine (8), which effectively improves thetightness and allows for better trunk motion. Also, he improved
his motor control by training using the concept of Pilates (9). He
then returned to competition in the second grade Nippon Professional Baseball (NPB) league at 2 months after surgery andwas able to join the first grade NPB league at 3 months after thesurgery. He eventually returned to his original level within thesame competitive season. The following year, he played extremely well and was selected as one of the best players.

DISCUSSION

Figure 3

Case 2 : CT images reveal the osseous remnant of apophyseal ringfracture at S1 (a, b).
MRI T2WI show lumber disc bulge at L4/5 (c) and herniation atL5/S (d).
Spinal canal stenosis at L4/5 (e) and lateral recess stenosis at L5/S (f)are evident on myelograms.

Figure 4

Case 2 : Postoperatively, bony fragment seems to overhang the spinal
canal (a, b) ; however, the fragment was snapped off when it wasimpacted, to avoid pressing on the cauda equina.
MRI T2WI shows lumbar disc herniation is almost removed andstenosis is resolved (c, d).

Apophyseal ring fracture is an avulsion vertebral fracturecaused by chronic stress and repeated trauma (1-5). The posterior apophyseal ring is highly stressed during extension and thiscan cause weakness of the ring. The weakened posterior area isavulsed following traction stress in flexion (1,2,3,4,5). Conservative treatment is usually chosen for patients with apophyseal
ring fracture. In general, surgical treatment is considered for
symptoms recalcitrant to conservative treatment.
Regarding accuracy of diagnosis, CT is considered the best
tool to detect the presence of bony fragment. Kadam et al. (10)reviewed the case of a 15-year-old boy and reported the clinicalimportance of CT scan to detect the lesion. In both our cases,
only plain radiographs and MRIs were obtained. CT scan had
not been done at the time they presented to our center. A clear
understanding of the osseous condition is essential to ensure
a precise management strategy for high-level athletes. Case 1
had a 4-year history of symptoms, which is unlike typical casesof herniation. HNP usually resolves spontaneously (11,12), anddoes not persist for long (12). Ramos Amador et al. followed 118
HNP cases using MRI, and found that 83% of cases showedspontaneous disappearance of the HNP mass within a year.
Thus, we suspected an atypical condition in Case 1, and so
performed CT scan. The pain may have persisted because of theHNP in the narrowed lateral recess due to the residual bony
fragment. If we suspect the existence of bony fragment duringfollow up patient of lumbar HNP, we should take CT scan assoon as possible. However, we have to consider that CT also has
problem of radiation exposure to patient.
Indications for surgery are important for high-level athletessuch as professional players like Case 2 in this report. For Case
1, the decision to perform surgery was relatively easy, because of
the longer duration of symptoms (i.e. 4 years). On the other hand,
we thoroughly discussed the indications for surgery for Case 2
because of the shorter duration of symptoms (i.e. 17 days). We
then decided on acute intervention by surgery for the following
reasons :1. He presented with muscular weakness, and muscle atrophy
due to prolonged weakness is rather disadvantageous for professional athletes.
2. Chronic compression of the nerve root by both the bony
fragment and the HNP would have caused the tight hamstrings (6), which in turn would not be good for professional
performance.
3. HNP typically exists in a narrow lateral recess due to thebony fragment, so the pain may not subside quickly. Inpatients with this condition, it was reported that the mean
duration of symptoms was more than 1 year (7). Indeed, Case
1 had a 4-year history of pain.
Regarding outcomes, this player returned to the first grade
NPB league 3 months after surgery in the same regular season.

The Journal of Medical Investigation Vol. 66 August 2019
By the next season the following year, his performance wasremarkable and at the end of the year he was selected as one of
the best players. For this player, we cannot directly compare outcomes with those obtained by conservative treatment ; however,his performance strongly supports the fact that our decision wassatisfactory.
Finally, we discuss the indications for surgery in HNP withthe residual bony fragment of the apophyseal ring fracture inadults. Basically, HNP can undergo spontaneous reduction(11,12), and thus conservative treatment would be the firstchoice, even though the HNP typically exists in the narrow lateral recess caused by the bony fragment. Interestingly, Akhaddar
et al. (7) reported that HNP combined with apophyseal separation may prolong clinical course. Mean duration of symptoms
was 16 months, twice longer than that in patients with only HNP(i.e. 8 months).
Taken together, these findings led us to conclude that in casesof HNP with apophyseal ring separation, surgical intervention
in the comparatively early phase can be recommended, particularly if the patients desire a quick return to their original levelof activity.

CONFLICT OF INTERESTS-DISCLOSURE
Nothing

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