Simon Olivotto presents a case study about visceral referred pain masquerading as musculoskeletal symptoms.

This case describes an unusual presentation of persistent thoracolumbar and flank pain in an otherwise healthy young female. She was found to have an underlying pelvic urinary tract junction (PUTJ) obstruction causing severe hydronephrosis as well as a low-grade non-invasive papillary bladder tumour. The presence of mechanical features combined with a lack of obvious red flags contributed to this patient undergoing prolonged, unnecessary treatments and delayed the diagnosis of the underlying cause.

This case highlights the need to recognise that the symptoms of visceral pathology can masquerade as musculoskeletal symptoms, which may exhibit both mechanical and non-mechanical features.

Presentation and clinical history

A 23-year-old female Royal Australian Navy member with a two-year history of persistent thoracolumbar pain was referred for a second opinion from another physiotherapist. Her symptoms were progressively worsening in intensity and coincided with episodic right flank pain. These symptoms were not improving with physiotherapy.

The onset of symptoms occurred gradually over two years; however, the patient considered that a fall while on a ship three years earlier was possibly related. At the time, a rogue wave had caused her ship to list unexpectedly and she fell against a bulkhead, injuring her right thoracolumbar region. She recalled bruising and abrasion to her right flank and thoracolumbar spine in a similar area to which she was experiencing her most recent symptoms. As she was at sea, she had no imaging or investigations at the time of injury and was only managed with restricted work duties and ibuprofen for analgesia. After a month, she reported substantial improvement and was subsequently able to return to full duties and the fitness requirements of her military role without further symptoms.

Eighteen months later the patient sought medical care for similar thoracolumbar pain, which coincided with a new onset of intermittent right flank pain. She was unable to recall a defined cause or temporal onset and reported inconsistent patterns of pain provocation. With her history of trauma, she was referred for an X-ray of thoracic spine, ribs, lumbar spine and pelvis. This did not show any evidence of recent or old fractures. After failing to improve over the next six months, she underwent a CT scan of her thoracolumbar spine. There was no evidence of any bony trauma, disc herniation, or any neural compromise, but an incidental three millimetre renal calculus of the right kidney without obstruction was reported. No further investigations were undertaken. Over the course of the next two years she sporadically attended medical appointments for which she received ibuprofen for analgesia and was referred for several short courses of physiotherapy.

She reported some relief and lessened severity of thoracolumbar pain with physiotherapy consisting of thoracic mobilisations and soft tissue therapy. Despite multiple treatments with different physiotherapists, her symptoms were gradually worsening and spreading with episodic referral to her right flank.

The patient’s goals when attending the initial physiotherapy appointment with the author included understanding what was causing her pain, and to gain insight and strategies to reduce and abolish her symptoms.

Since her fall, this patient was without symptoms for 18 months and subsequent imaging had ruled out any bony injury in the thoracolumbar region. She had a regular menstrual cycle, no history of corticosteroid use, or osteopenia, suggesting that fracture was an unlikely diagnosis (Downie et al 2013). There were no neurological symptoms, no changes in bladder or bowel control, ataxia or weakness, no unexplained weight loss and no history or family history of cancer. She reported no autonomic symptoms, was otherwise well with no signs of, or family history of, inflammatory arthropathy, and had no recent viral illness.

She described that prolonged sitting in a forklift for greater than two hours, as well as repetitive manual handling of stores, exacerbated her thoracolumbar symptoms but not her flank pain. Her flank pain was triggered by cold weather as well as consumption of alcohol. These also worsened her thoracolumbar symptoms. She reported infrequent episodes of thoracolumbar and flank pain waking her at night for no obvious reason, but that rest sometimes alleviated her thoracolumbar pain. She was unable to do anything to improve flank symptoms, although manual therapy, as well as stretching her spine on a foam roller, sometimes helped ease her thoracolumbar pain.

With diffuse widespread symptoms and sometimes unpredictable pain provocation, features of central sensitisation were considered. Further targeted questioning suggested there was no evidence of stress, negative emotions, poor self-efficacy, unhelpful beliefs or pain behaviours, which contributed to persistent pain states (Smart et al 2012). She had no history of any co-morbid functional pain disorders, which tend to be associated with altered central pain processing mechanisms.

Clinical reasoning after subjective history

The temporal relationship and non-mechanical features of the patient’s flank and thoracolumbar symptoms suggested they were both likely related to a common underlying cause. The history of blunt renal trauma, spread of pain to her flank, night pain unsettled by change in position or movement, as well as symptoms associated with alcohol consumption, raised clinical suspicion of underlying renal pathology being responsible for both+. A co-existing musculoskeletal contribution could not be ruled out as a hypothesis to explain her thoracolumbar pain.

Therefore the purpose of the physical examination was to:

• confirm or exclude a non-mechanical pattern for both areas of pain in order to strengthen the rationale for referral


• assess any primary or co-existing mechanical contributions to her thoracolumbar symptoms and therefore determine any additional strategies for symptom relief.

Physical examination

Functional assessment was undertaken to assess the aggravating activities of sitting in a forklift, squatting and lifting a 10 kilogram box. During each of these tasks the patient displayed an upright active thoracolumbar extension pattern of trunk muscle bracing. She was able to reduce thoracolumbar symptoms in these tasks from 5 to 2/10 with a posterior pelvic tilt, reducing active extensor bracing.

Diaphragmatic breathing reduced her resting extensor tone, and thoracolumbar symptoms improved from 5 to 2/10. In all instances, her flank pain remained unchanged, which strengthened the hypothesis of a non-mechanical cause.

Thoracolumbar active range of movement (ROM) increased right thoracolumbar pain in both left and right rotation at approximately 45 degrees. Testing rotation in various degrees of thoracic kyphosis and extension as well as varying pelvic tilt had no effect on symptoms; however, repeated ROM displayed a small change in ROM and thoracolumbar pain. Lumbar ROM testing did not affect symptoms except for end-range flexion, which reduced thoracolumbar pain to 2/10, but did not change the flank symptoms. Slump testing to assess neuromechanosensitivity had no appreciable effect on symptoms.

Pain and muscle guarding were evident with passive accessory intervertebral movement (PAIVM) testing as well as with right rotation passive physiological intervertebral movement (PPIVM) testing at the right thoracic T8–L2 intervertebral joints. Light palpation and punctate sensory testing of the right thoracolumbar para-spinal region as well as the right flank indicated hyperalgesia rated 7/10 compared with 2/10 on her left side. Reassessment of thoracic ROM testing was performed again after PAIVM and PPIVM testing as well as relaxed diaphragmatic breathing, but there was no appreciable change in symptoms or ROM.

Clinical reasoning after physical examination

The clinical assessment did not demonstrate any obvious mechanical contribution to her flank pain in particular. It was explained to the patient that since both symptoms displayed non-mechanical behaviours, she would benefit from further medical investigations.

The mediating effect of posture and motor control on thoracolumbar symptoms suggested these may still be worthwhile to address, even if only as a strategy to provide temporary or partial symptom relief.

Management

The patient agreed to make an appointment with her GP. A trial of relaxed diaphragmatic breathing and posterior pelvic tilt strategies to be implemented during prolonged sitting and manual handling work tasks was suggested, with a frequency of at least once per hour. Thoracolumbar rotation mobility exercises in side lying were also advised as a way to also reduce extensor tone via reciprocal inhibition and improve ROM in a gravity assisted position. She was re-assessed two days later (just prior to her GP appointment), and while these strategies had provided some short-term relief, overall her symptoms had remained unchanged. This response further heightened suspicion of a non-mechanical contribution responsible for her symptoms.

The patients GP was consulted and made aware of my concerns. She was referred for a right kidney ultrasound and further specific testing of abdominal pelvic scan with contrast (Figure 2). This found a severe right- sided hydronephrosis with delayed excretion, consistent with PUTJ obstruction. She was promptly referred to a urologist and underwent a cystoscopy. During this procedure an incidental low-grade non-invasive papillary tumour in the bladder was also found and surgically removed. She had a uretic stent implanted and four weeks later a laparoscopic pyeloplasty to remove the stent. Since the obstruction had been cleared, she also passed the renal calculus. During this time she had no further physiotherapy.

Results and follow up

Seven months since these surgeries, the patient reported that her thoracolumbar and flank pain were no longer present. Her flank pain resolved almost immediately after surgery. Her thoracolumbar symptoms took a further two months to improve with continuation of the pelvic tilt and diaphragmatic breathing strategies. Consumption of alcohol and cold weather no longer caused her any symptoms. She returned to her usual duties including driving forklifts and repetitive manual handling of stores without any further pain.

This patient was reviewed by her urologist at six months with no further signs of PUTJ obstruction or tumour recurrence. Ongoing annual urologic review and periodic cystoscopy is planned to ensure no return of the tumour and obstruction.

Discussion

Somatic and viscero-somatic referred pain mechanisms exhibit similar behaviours and may be difficult to distinguish with clinical testing alone (Yelland & Harding 2007). While this patient experienced initial trauma and subsequent musculoskeletal back pain, the non-mechanical characteristics, as well as the sustained improvement of her flank pain and thoracolumbar pain after surgeries, suggest that the renal pathologies were likely to be the primary contributor to both areas of pain via a visceral referred pain mechanism. Alcohol consumption and cold are both features that are known to lead to diuresis and increased urine production, which could explain her symptoms due to increased visceral nociception via distension of the kidney (Jones 1990, Sun & Cade 2000).

Visceral nociception usually presents with acute deep, dull and poorly localised pain which is often associated with strong autonomic features (Sikander & Dickenson 2012). However, following prolonged periods, referred pain symptoms may be the only feature (Procacci & Maresca 1999). The gradual and progressive nature of this patient’s pain over the two years is in keeping with the timeline of known progression of hydronephrosis pathology (Mesrobian & Mirza 2012) and may explain why this patient did not report any obvious autonomic signs.

Referred pain from visceral and somatic structures are both thought to arise due to convergent afferent input synapsing with common second- order projection neurons in the dorsal horn (Procacci & Maresca 1999). This causes spatial misrepresentation in the central nervous system and results in secondary hyperalgesia and pain perceived in sites remote from noxious afferent input (Kansal & Hughes 2016). The areas of thoracolumbar and flank pain experienced by this patient are possible referral patterns for thoracic zygapophyseal joints as well as for renal dysfunction (Ray & Modak 1987). This patient had positive signs with thoracolumbar joint pain provocation on manual testing. However, research in other non-musculoskeletal conditions (eg, migraines) suggest these findings alone lack the specificity to confirm a musculoskeletal structure as the primary source of symptoms (Calhoun et al 2010).

The mechanical behaviour of this patient’s thoracolumbar symptoms can be explained by viscero-somatic pain mechanisms. Prolonged afferent barrages of visceral nociception can activate somatic efferent reflexes, which result in a sustained motor response in skeletal muscle tissue (Kansal & Hughes 2016). This, along with antidromic activation of C fibres, can contribute to sensitisation of peripheral nociceptors and can further propagate local somatic pain (Procacci & Maresca 1999, Graven-Nielson 2006).

Postural tasks were likely to be increasing load on sensitised thoracolumbar somatic tissue. Previous manual treatments probably helped in the short term to reduce this via both peripheral and central neuromodulation mechanisms (Bialosky et al 2009). Somatic changes have also been shown to persist once underlying visceral causes have resolved (Anand et al 2007, Giamberardino et al 2010). This may also explain why her thoracolumbar symptoms required a further two months of postural exercises to fully recover following surgery.

The patient’s history of a fall was one feature that raised suspicion for potential renal injury from blunt trauma to her flank. Severe hydronephrosis can develop acutely after blunt renal trauma, but for it to occur several years later is extremely rare (Lee et al 2006).

The treating urologist reported an aberrant arterial blood vessel was causing the PUTJ obstruction and believed the initial fall was unlikely to have contributed to this in any way. The early-stage papillary bladder tumour found in surgery was also considered a coincidental finding and unrelated to her renal pathology. She had no red flags for this apart from episodic night pain, which in itself is not a useful diagnostic indicator for malignancy (Premkumar et al 2018). This further highlights the challenges in diagnostic accuracy of a red flag screening, especially in detecting early-stage malignancies.

On reflection, it is easy to see how this patient’s mechanical features, including short-term responses to manual therapy and postural factors, could lead to persevering with physiotherapy treatment. However, a failure to demonstrate sustained improvements within a reasonably expected timeframe should always be a cause to re-evaluate management. This patient’s history provided clues of non-mechanical features that were consistent with renal involvement. The clinical examination did not provide any conclusive proof to refute this and referral to her GP was made. Recognising that mechanical symptoms can co-exist as a secondary consequence of underlying pathology is an important concept for clinicians to understand in order to avoid missing serious conditions masquerading as musculoskeletal pain.

The patient gave consent for her case to be presented and discussed.

I would like to thank Alastair Flett FACP, Gwendolen Jull FACP, and Debra Shirley FACP for their assistance in reviewing, assessing and preparing this case study.

Email inmotion@australian.physio for references.

APA Musculoskeletal Physiotherapist Simon Olivotto works for the Department of Defence at Garden Island Navy Base in Sydney, NSW. In addition to this, Simon also works a part-time primary contact emergency department role on weekends, and is currently undertaking the two-year musculoskeletal specialisation training program.