Abstract
INTRODUCTION:
Running is one of the most common sports practices in the world due to the beneficial impact on the health, despite the relatively high risk of getting injuries. In fact, running is one of the most common sports capable to induce overuse injuries of the lower back and leg. In previous studies, the symptoms in the lower limb have been attributed to lumbosacral degenerative pathology. When the symptoms are unclear, they must be studied with great attention by carrying out an accurate process of screening and differential diagnosis.
MATERIALS AND METHODS:
A 42-year-old non-competitive male runner who complained of left leg pain was referred to a physiotherapist. He reported a continuous, deep, sharp, shooting pain of the left leg. The symptoms began one year earlier. Symptoms worsened during prolonged driving and long distance running. The patient had been previously diagnosed with lumbar radicular irradiation in the leg by a general practitioner. Initial management, in another physical therapy outpatient setting, was without any improvement.
RESULTS:
After surgical excision, symptoms gradually regressed shortly and the patient was referred to a physiotherapist in order to fully recover and restore work and running activities.
CONCLUSION:
This case report describes the history, assessment and treatment of a runner with a rare cause of leg pain. After surgery excision, treatment focused on education and loading the tissues over many weeks through a graded program of loaded exercises and running retraining.
Introduction
Running is one of the most common sports practices in the world, due to the low running costs and the beneficial impact on the health ranging from the improvement of the cardiovascular system and the reduction of mortality risk to the reduction of the incidence of obesity and the improvement of many chronic health problems [1, 2]. The importance induced by the media concerning health, diet, fitness and competitive athletics has brought an increase in levels of physical activity even in subjects without preparation and training methodology [3], thus identifying the relatively high risk of getting injuries as the primary drawback of running [1, 2].
In fact, running is one of the most common sports capable to induce overuse injuries of the lower back and the leg [4]. In particular, the incidence of lower extremity injuries in runners ranges from 19.4% to 79.3% [1]. The most common diagnoses for pain in lower leg include dysfunctions such as patellofemoral pain; medial tibial stress syndrome (shin splints); achilles tendinopathy; iliotibial band syndrome; plantar fasciitis; and stress fractures of the metatarsals and tibia [1, 5, 6, 7, 8]. In other cases, the symptoms in the lower limb have been attributed to lumbosacral degenerative pathologies [9, 10, 11] such as low back pain (LBP) or lumbar radicular syndrome [12]. LBP and radicular syndrome are considered benign conditions and are usually managed quite easily [13, 14]. When the symptoms are unclear, these clinical conditions must be considered with great attention by carrying out an accurate process of screening and differential diagnosis [13]. In fact, in this case the correlation between symptoms and serious pathology was not always clear and the lumbar radicular syndrome could delay the diagnosis and more appropriate treatment. This case report represents an emblematic example. The patient presented symptoms in the lower left leg and had been diagnosed with LBP with radicular syndrome, but it turned out he was affected by schwannoma in the superficial peroneal nerve.
Case presentation
A 42-year-old non-competitive male runner who complained of left leg pain was referred to a physiotherapist. He reported a continuous, deep, sharp, shooting pain and a superficial burning sensation in the anterolateral aspect of the left leg. The symptoms began one year earlier with an insidious onset and were not associated with any trauma or injury. Symptoms worsened during prolonged driving and long distance running (i.e. 10–15 km). Symptoms began in concomitance with the start of the running training, and pain was almost constant with an intensity of 7/10 at Numeric Pain Rating Scale (NPRS) [15]. The patient was previously diagnosed with LBP and radicular irradiation in the leg by a general practitioner (GP) that prescribed a lumbar Magnetic Resonance Imaging (MRI). Initial management, in other physical therapy outpatient settings, included physiotherapy (lumbar massage, exercise for lumbar spine), physical therapy modalities (i.e. tens), and spinal manipulation, all without any improvement.
Physical assessment
During the history examination, the patient reported a previous episode of LBP in the past, but noted that it always resolved spontaneously without any specific treatment. In fact, he presented LBP with an intensity of pain of 1-2/10 NPRS. Our physical examination did not reveal any impairments on the lumbar spine (range of motion (ROM)) were normal and the pain was not exacerbated by back movements or coughing). Neurological examination was also normal; no obvious motor or sensory deficit was noted, Lasegue’s test was negative and osteotendinous reflexes were normal. Furthermore, the patient was healthy and had no past medical problems. Furthermore, the MRI scans of his lumbar and sacral spine were normal. To make a diagnosis, the lumbar spine was excluded and the screening process focused specifically on the leg. Additional provocative and functional tests were performed on the symptomatic leg. The fulcrum sign, single leg hops and peroneal percussion test were negative and the ROM of the knee and ankle were normal. However, there was a significant increase of the familiar patient symptoms during superficial palpation close to the fibular head and during resisted dorsiflexion of the foot. An accurate local deep palpation of the upper third of the anterior part of the left leg, around the fibular head, revealed an isolated oblong soft-tissue mass sensitive to percussion, which has been gradually increasing in size for more than one year but was never mentioned by the patient in other medical examinations. A nodular formation in the soft tissue raised the suspicion of a neurinoma of superficial peroneal nerve [9, 14, 16]. With this diagnostic hypothesis the patient was referred for ultrasonography that showed an oval formation in proximity of the fibular head (Fig. 1). A successive MRI (Figs 2 and 3) confirmed the diagnosis of neurinoma of peroneal nerve.
Longitudinal ultrasonography image reveals oval formation in proximity of the fibular head (yellow arrow – colour in the online version).
Sagital view. MRI (in T2 with fat suppression) imaging studies of the patient’s left leg. Tumor visible on the lateral leg compartment below the level of the left fibular head (yellow arrow – colour in the online version).
Axial view. The Schwannoma with high signal intensity in T1 weighted axial left leg MRI. Tumor visible on the lateral aspect of the left fibular head (yellow arrow – colour in the online version).
Lateral view. Scar of surgical excision in the left leg (yellow arrow – colour in the online version).
After surgical excision of the neurinoma (Fig. 4), symptoms gradually regressed and the patient was referred for physical therapy in order to fully recover and restore work activities and running. A schwannoma of superficial peroneal nerve was diagnosed through histological analysis. The patient completed a total of 12 visits over the course of 24 weeks. In the first phase, manual therapy (passive joint mobilization and mobilization with movement) was performed for restoring the full knee and ankle range and pain relief. The patient visited three times a week. Relief of these symptoms should be a priority in order to gain patients’ trust, to facilitate active engagement and to optimize long-term outcomes [17]. In the second phase, the patient was instructed to undergo an exercise program. He was asked to perform prescribed exercises three times a week for three weeks. Exercises were dosed and progressed according to pain levels and the number of repetitions reached. Subsequently, three times a week for three weeks, the treatment program aimed to progressively increase the exercises functional demand and load, progressing exercises from no-weight bearing to weight bearing. Weekly meetings were scheduled to ensure proper execution of exercises and gradual progression of loads [17]. In the third phase, in line with the literature, the running retraining program was performed [18] for five weeks. Various options required consideration, including strategies to step rate manipulation, reduce overstride, altering strike pattern, reducing impact loading variables, increasing step width and altering proximal kinematics. In fact, by optimizing the amount and frequency of loading stress, injuries could be avoided [4]. The patient received a personalized running program over 12 weeks (five sessions per week, alternating between running and walking, with two rest days between).
Discussion
Schwannoma, also called neurinoma or neurilemmoma, is a benign peripheral nerve sheath tumor [9], and is the most common of its sort [19, 20, 21]. They make up 5% of benign soft tissue tumors [16], and are frequently seen between the ages of 20 and 50 [16]. Cases of common peroneal nerve schwannomas are very rare in the literature [16], and diagnosis can be delayed for a long period of time, since symptoms are usually attributed to lumbosacral degenerative pathology [9, 10, 11]. Schwannomas usually have a clinically silent course, though the present case highlights how a peroneal nerve schwannoma can become symptomatic due to mechanical compression, resulting in pain, swelling or a lump [16]. A mismatch between the resilience of the viscoelastic properties of the connective and supporting tissue during running [22] and an increase in levels of physical activity without preparation and training methodology [3], could have triggered the symptoms in this case report. In fact, literature confirmed that patients after changing their load rapidly cause a deterioration of their symptoms [23], given the dynamic nature of the relationship between applied stress and injury [4]. Schwannomas are benign lesions and their surgical excision is generally definitive and malignant transformation is rare [16].
Conclusion
In sports medicine, history and physical examination are considered the core for making the diagnosis [24]. A reliable diagnosis is important for both clinical practice and research. From a clinical practice and research perspective, it is important to identify lower leg injuries in a correct and reliable manner, as this may change the prognosis and treatment in practice, and may alter the eligibility of the candidate athlete for participation in a clinical trial. Therefore, it is important to consider differential diagnoses [24]. The current case highlights the importance of a thorough physical assessment in the presence of an atypical clinical manifestation as it specifically targeted the investigation by imaging and prompt investigation, which helped to make the correct diagnosis and initiate appropriate treatment. This case report describes the history, assessment and treatment of a runner with a rare cause of leg pain. After surgery excision, treatment focused on education and loading the tissues over many weeks through a graded exercise program and running retraining.
Footnotes
Acknowledgments
We would like to express our gratitude to the patient of this case report.
Conflict of interest
The authors declare they have no competing interests.