Avulsion fractures of apophysial ring ("limbus") posterior superior of the L5 vertebra, associated to pre-marginal hernia in athletes

Abstracts

O aumento de adolescentes praticando esportes de forma cada vez mais competitiva tem causado o aumento de lesões relacionadas à prática desportiva. A dor lombar é uma queixa freqüente entre os atletas, geralmente relacionada a contraturas da musculatura paravertebral e fraturas ( espondilólise ) devido ao excesso de treinamento e aplicação de técnicas incorretas. Porém, outras etiologias podem causar a dor lombar, como processos infecciosos, tumorais e fraturas. As fraturas com arrancamento do anel apofisário são lesões incomuns e raramente ocorrem na região póstero-superior da vértebra L5. Os relatos da literatura mostram que o local mais acometido é a região póstero-inferior da vértebra L4. Apresentamos dois casos de atletas jovens com esta incomum lesão. O objetivo deste trabalho é discutir a possível etiologia, os melhores métodos para o diagnóstico e possíveis formas de tratamento desta patologia.

Fratura com arrancamento; anel apofisário; hérnia discal pré-marginal

ARTIGO ORIGINAL

Avulsion fractures of apophysial ring ("limbus") posterior superior of the L5 vertebra, associated to pre-marginal hernia in athletes

Eduardo Barros Puertas^I; Marcelo Wajchenberg^II; Moisés Cohen^III; Mario Néia Isoldi^IV; Luciano Miller Reis Rodrigues^V; Paulo Satiro de Souza^V

^IPhD in Orthopaedics, Head of the Spine Group

^IIAssistant doctor of the Spine Group and of the CETE

^IIIPhD in Ortopaedics and Head of the CETE

^IVOrthopaedic Surgeon and Specialist in Sports Medicine by CETE

^VAssistant Doctor of the Spine Group

^{Correspondence}

SUMMARY

The number of sport related injuries has raised as the increasing number of adolescents practicing competitive sports. Lumbar pain is a frequent complaint among young athletes. It is usually related to the contracture of paravertebral muscles and fractures (spondylolysis) caused by excessive practicing and incorrect techniques. However, other etiologies can cause lumbar pain, such as infectious processes, tumor and fractures.

Avulsion fractures of the apophysial ring are uncommon lesions which rarely happen in the posterior superior area of the L5 vertebra. The literature shows that the most susceptible place to injuries is the posterior inferior area of the L4 vertebra. This paper presents two cases of young athletes with this unusual lesion. The objective of this work is to discuss the possible etiology and the best diagnostic and treatment procedures for this pathology.

Key words: Avulsion fractures of spine, spine lesions in athletes, apophysis ring lesions.

INTRODUCTION

Low back pain is a common complaint among athletes, however, most of the times, the diagnosis given to the athlete is of a back pain related to paravertebral muscles contraction. Plain radiographs, generally add few information to the examiner, however subtle local changes may justify the necessity of other exams, such as TC scan or MRI. Spondilolysis is the most frequent spinal bone injury in athletes, involving mainly L5, however other diseases are important as differential diagnosis, such as infections, tumors and fractures.

Avulsion fractures of the posterior part of apophysial ring are rare ⁽⁴⁾, with few reports in literature. The first report of this pathology was made by Lowrey⁽⁸⁾ in 1973, with a surgical treatment of a teenager presenting sciatalgia, caused by radicular compression. The most frequently involved place is the posterior region of the inferior plateau of the L4 vertebra^(6,7). We present the cases of two athletes, one soccer player and one weight lifter, with avulsion fracture of the posterior superior apophysial ring of L5 vertebra, associated to a pre-marginal disc herniation.

CASES AND METHODS

Case 1

A.L.D.T., 17 years old, male, weight lifter, practiced daily (5 days/week). Came for medical assistance reporting lumbar pain for 2 months, with worsening of the symptoms and incapacity after crouching with excessive load. The patient did not report any symptom of irradiation to lower limbs. At initial physical examination, it was noticed intensive contracture of lumbosacral muscles, shortening of ischiotibial muscles and a relative relaxation of abdominal muscles. No neurologic change was found. Radiographic examination displayed a fracture, with a posterior displacement of a small bone fragment of superior plateau of L5 vertebra. This fragment could be better seen through a CT scan. In this examination, a left central lateral disc herniation was also identified.

The patient was treated with analgesics and NSAIDs, use of a lumbar orthesis, physiotherapeutic rehabilitation and rest of his physical activities for three months. After this period, complete relief of the symptoms was observed, and the patient allowed to a progressive return to his activities. He had no symptoms for 7 months.

Case 2

B.C.L., 22 years old, male, soccer player, came for medical assistance reporting severe lumbar pain with a severe sciatalgia irradiated to left lower limb with incapacity for practicing sport. The athlete remained with the symptoms for two months, until coming to our service. At physical examination a severe spasm of paravertebral lumbosacral muscles was noticed, with shortening of ischiotibial muscles. Lasègue maneuver was positive in left lower limb, and a slight hypotrophy of quadriceps with reduction of left patellar reflex was also noticed. Radiographs didn't show clearly any bone change. CT scan allowed seeing a bone fragment avulsed from upper plateau of L5 vertebra, posteriorly displaced trending to the left conjugation hole. The bone fragment was healed to the posterior wall of the L5 vertebra, and sclerosis could be noticed at the avulsion site as well. Sagital image (reconstruction) allowed a perfect localization of the bone injury. MRI allowed identification of the L4-L5 intervertebral disc, which presented signs of degeneration and dehidratation in sagital images weighted in T2, besides a voluminous left central lateral disc herniation, with root compression to left.

The patient was treated with analgesics and steroid anti-inflammatory, lumbar orthesis, physiotherapy and rest during two months, without any clinical sign of improvement, with increasing apprehension and anxiety. Surgery was indicated for hernia resection through a unilateral left laminectomy, with curettage of the bone fragment and foraminectomy besides disc herniation resection. The proposed surgery was performed without problems. The patient was discharge from the hospital 24 hours after the surgery, being submitted to hydrotherapy starting the fourth day after the surgery. During the first month after performing the surgery the patient remained without symptoms, with only shortening of ischiotibial muscles. He returned to play soccer competitively by the end of the third treatment month.

DISCUSSION

Avulsion fracture of apophysial ring is difficult to diagnosis and has few reports in literature^{(1,4,5,6,7,8)}. According to several authors, the most commonly affected place is the posterior inferior region of L4 vertebra^{(1,3,5,6,7,8)}. We present in this report of two cases the presence of this injury in the posterior superior region of L5 vertebra in athletes, one soccer player and one weight lifter.

Among the uncommon locations of this injury, it is important to say about the report of one case involving a soccer player who had a posterior displacement of the apophysis ring in the upper plateau of S1 vertebra, causing severe lumbosciatalgia due to compression of the S1 left root⁽³⁾.

It is described through the report of one case, the mechanism of injury in a teenager who practiced weight lifting, stressing the importance of forced flexion associated with axial compression⁽⁷⁾, in the etiology of the avulsion of the fragment of the posterior inferior margin of the body of L4 vertebra. In another case, happened the appearance of a bony elevation in the inferior plateau of the L3 vertebra in a 14 years old gymnastic practitioner, stressing the link between sports practicing and apophysial fracture in lumbar vertebrae⁽⁵⁾.

Several terms were use to classify this injury, as epiphyseal persistence, limbic bone, posterior bone avulsion and intraosseous posterior marginal cartilage lumbar node⁽⁶⁾.

It was suggested the name paradiscal defect, emphasizing the presence of the discal herniation primarily, causing a secondary form, the avulsion of the bone fragment ⁽⁴⁾. We observed the presence of disc herniation in both presented cases, being symptomatic in one patient. We believe that the discal herniation has a primary role in the physiopathology of the avulsion fracture of apophysial ring.

To explain the physiopathology of this injury, we understand that repeated micro traumatisms in young athletes, mostly through abrupt flexion and extension, and weight bearing⁽⁹⁾, could start injuries of epiphyseal cartilage and overload of intervertebral disc.

The intervertebral disc of the teenager and young adult has an increased turgor due to hydratation and the presence of polysacharides in the pulpous nucleus⁽⁶⁾. This nucleus exerts an increased pressure over the fibrous annulus, circunferencially and over the terminal plates, both cranial as caudally. The fibrous annulus is adhered to the upper and inferior vertebral plateau through the Sharpey fibers and some fibers of the longitudinal posterior ligament. The increase of the pressure by the pulpous nucleus over the fibrous annulus may lead to a discal herniation and the avulsion of the bone fragment from the terminal plate. There was the report of this mechanism through an illustration⁽⁶⁾.

The ossification of the vertebral terminal plate cartilage (apophysial ring) starts around the age of 5 years, being its ossification completed around the age of 18 years^(1,9), being possible in some individuals to persist up to the age of 25 years⁽⁴⁾. Some authors suggest that ossification defects of the apophysial ring, as those described in Schmorl's disease, could be associated to this pathology⁽⁹⁾.

The diagnosis of this pathology is difficult, since the clinical history and physical examination can lead to a diagnosis of muscular back pain and discal herniation, due to the presence of sciatalgia. Plain radiographs may demonstrate subtle changes and do not help the diagnosis. CT scan allows an excellent evaluation of the avulsed bone fragment⁽⁹⁾, mainly through the bi-dimensional reconstruction. However, this exam doesn't allow a perfect evaluation of the discal herniation and of the neural tissues. MRI allows the evaluation of the cartilaginous tissue, of the disc and degree of compression of nerve roots, allowing an adequate planning of the surgery, when necessary⁽⁹⁾.

The treatment of this disease is related to the degree of neural tissue compression and reaction to conservative measures. Surgical treatment should be performed when conservative measures are ineffective⁽³⁾ after several weeks. Surgical treatment consists in performing wide laminectomy (bilaterally) with discectomy and removal of the bone fragment⁽²⁾. We believe that a laminectomy can be performed only on the affected side preserving the facetary joints thus avoiding instability, as performed in Case 2. Release of the compressed root can be performed through a small incision, with minimal damage to ligamental and muscular structure, using a microscope through a minimally invasive technique. This procedure is very important for athletes, who need to resume their physical activities as soon as possible.

During treatment of the athletes it is important to have a multi professional approach, involving doctor, physiotherapist, coacher, sponsor, being necessary a psychological support since being out of activity may bring economic, social and emotional conflicts.

CONCLUSIONS

Avulsion fracture of the apophysial ring is an uncommon disease, and rarely involves the posterior superior plateau of L5 vertebra, according to the reported in this paper. This injury has a close relationship to repeated micro traumatisms occurring during sport practice. The injury described through report of two cases is related to marginal disc herniation in teenagers and young adults.

Avulsion fracture of apophysial ring is a pathology that should be always considered in differential diagnosis of back pain and sciatalgia in athletes. Clinical history and physical examination are inconclusive, being necessary complementary exams for diagnosis. CT allows identifying the avulsed bone fragment and MRI to study the intervertebral disc and nervous structures.

Treatment of this injury is dependent of patients clinical picture and reaction to conservative treatment, being important a multi professional approach taking into consideration peculiarities and anxieties of the athlete.

REFERÊNCIAS BIBLIOGRÁFICAS

Work performed in the Centro de Traumatologia do Esporte (CETE) of the Departamento de Ortopedia da Universidade Federal de São Paulo - UNIFESP - EPM

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Publication Dates

• Publication in this collection
  21 Sept 2005
• Date of issue
  Mar 2002