A 22-years old female, swimming champion  presented with a history of low back pain of 2 years duration. The back pain was mechanicalin nature and associated with pain in the left lower limb up to the level of the knee joint. The left lower limb pain was non radicular in nature and not aggravated on coughing or sneezing.

Patient developed her first episode of severe pain during swimming training abroad for which medical consultation was obtained. Plain radiographs, CT scans  & MRI investigations showed sclerosis of the pars region of L5 vertebra on the left side. There was also some suggestion of elongation of the pars. The fact that the pain had developed in a professional swimmer during a course of intense training and the classical radiological picture led to a suspected diagnosis of stress fracture with partial healing of L5 pars interarticularis on the left side.  Radiographic evidence of elongation of pars of L5 was also a pointer towards stress fracture of the pars.

Patient was accordingly treated with a short period of bed rest followed by restricted mobilization with lumbosacral corset. Patient had short-lived relief with this treatment. The pain reappeared after some time preventing her from continuing her training.

On presentation to us, she was investigated with repeat radiographs in both the planes, MRI, CT scan and bone scan.Investigations revealed the presence of bony eburnation around the medial facet and extending on to the pars of L5 on the left side with a nidus suggestive of an osteoid osteoma. (Figure 1 a&b).
 

Figure1-a	Figure1-b

Patient had a  microsurgical excision of the lesion. In view of the sports career of the patient, meticulous care was taken during the surgical excision  not to violate the facet joints at L4-5 and L5-S1 levels. Material collected during surgery was sent for histopathology and the diagnosis of osteoid osteoma was confirmed. Patient noticed immediate significant symptomatic relief following the surgery.

Post opeative MRI confirmed adequate excision of the lesion (Figure 2). At final follow up (3 months post-op), patient was adequately rehabilitated and was back to her swimming career (Figure 3).
 

Figure 2	Figure 3

 

Points to note in this case

It is important to thoroughly investigate a young patient presenting with persistent back  pain. Failure to respond to an established modality of treatment for an etiology should lead to further assessment to confirm the diagnosis.  Surgical treatment in these cases should be tailored to the professional career of the patient and should preferably aim at the minimum possible intervention.