Facet Pain

Decoding Lumbar Facet Joint Pain: Unraveling Controversies and Clarity in Diagnosis and Treatment

RESEARCH REVIEW ON FACET JOINT PAIN AND HOW DYNAMIC DISC MODELS HELP

increasing precision and reducing fears

Introduction

In this narrative review published in Pain Practice, we delve into the realm of pain originating from the lumbar facet joints. This update builds upon the foundations laid in the 2010 article titled “Evidence-based Interventional Pain Medicine According to Clinical Diagnoses.”1 Pain emanating from the lumbar facets can be succinctly defined as discomfort arising from the innervated structures within the joint, including the subchondral bone, synovium, synovial folds, and joint capsule. Notably, the articular cartilage itself lacks neural innervation.

Medial Branch and Nerve Facet Model

However, simplicity in definition belies the complexity and controversy that often shrouds the diagnosis and treatment of lumbar facet joint pain. Various studies have reported a wide-ranging prevalence of this condition, spanning from 4.8% to over 50% among individuals experiencing low back pain. The discrepancies primarily hinge on the criteria employed for diagnosis and patient selection, with more stringent criteria yielding lower prevalence rates. High-quality studies utilizing controlled blocks typically place the prevalence rate between 10% and 20%, with an increased incidence among the elderly.

Lumbar facet joints are anatomical structures formed by the articulation between the inferior articular process of the superior vertebra and the superior articular process (SAP) of the inferior vertebra, contributing significantly to the posterior articulation of the lumbar spine. Interestingly, as one descends from L3 to S1 along the lumbar column, the orientation of these facet joints evolves from the sagittal plane (which provides resistance against rotational forces) to the coronal plane (which offers superior protection against forward flexion and shearing forces), with the most robust transverse articular orientation occurring distally.

An intriguing feature of lumbar facet joints is their dual innervation pattern. Unlike the cervical spine, where medial branches are differently named due to the C8 spinal root’s unique position, each lumbar facet joint receives innervation from the medial branches of the named nerve at its upper level and from one level above. These medial branches also influence the multifidus muscle, interspinous ligament, and muscle.

The journey of the medial branch begins from the ramus dorsalis of the spinal nerve, which concurrently serves as the source of lateral and intermediate branches. Subsequently, the medial branch courses beneath the mamillo-accessory ligament, maintaining its consistent location and branching to the facet joints both above and below. The L5 dorsal branch diverges slightly, running in the groove between the SAP and the sacral ala, offering unique treatment possibilities.

Medial Branch Ablation approach parallel
A) Parallel insertion of electrodes. Parallel placement may result in a higher likelihood of missing the
nerve than with near-parallel orientation.

Methods of the paper

This narrative review draws its foundation from the 2010 article titled “Pain originating from the lumbar facet joints.” In 2015, an independent entity, Kleijnen Systematic Reviews, conducted a meticulous, systematic review spanning the years 2009 to 2015. This comprehensive review leveraged existing systematic reviews (SRs) and randomized controlled trials (RCTs). For the present article, an updated search was executed, encompassing the timeframe from 2015 to 2022. The search terms employed included “lumbar” and “facet,” coupled with “pain” within the context of interventional pain management techniques. Specifically, the search focused on keywords like “injection,” “intra-articular,” “medial branch block,” and “radiofrequency.” Additionally, authors had the discretion to identify and incorporate any pertinent articles that may have been overlooked during the search process.

DIAGNOSIS: UNVEILING THE COMPLEXITY OF LUMBAR FACET JOINT PAIN

When navigating the intricate terrain of diagnosing (chronic) low back pain, it becomes evident that various psychosocial factors can exert a significant influence on the patient’s experience. Therefore, the process of diagnosis should extend beyond a mere physical examination. It must encompass a comprehensive and multidimensional evaluation, considering how pain interlaces with daily activities and the individual’s overall quality of life. Equally important is the screening for red flags that might signal underlying conditions such as cancer, infection, trauma, or systemic neurologic issues.

However, it’s crucial to acknowledge that pain originating from the lumbar facet joints doesn’t present with pathognomonic signs or symptoms. Instead, clinicians rely on various factors to unravel the diagnostic puzzle. These include the location and referral patterns of pain, its onset and duration, the quality of pain, factors that exacerbate or alleviate it, and diagnostic imaging.

A common thread in patient reports of lumbar facet joint pain is axial low back pain, which can manifest unilaterally or bilaterally. Pain stemming from the upper facet joints can cast its pain shadow over the flank, hip, groin, and thigh regions. In contrast, pain originating from the lower facet joints tends to gravitate towards the posterior thigh. It’s a rarity for facet-related pain to extend distally beyond the knee.

Typically, patients describe this type of pain as a persistent ache that intensifies during activities devoid of neuropathic characteristics or radicular distribution. However, it’s worth noting that nociplastic features like tingling and allodynia may occasionally accompany lumbar facetogenic pain. Since facet joints play pivotal roles in the spine’s principal movements, pain can intensify during extension, flexion, rotation, or uphill walking. Additionally, it can be triggered by static positions, such as prolonged standing or sitting, and upon awakening from sleep, often accompanied by morning stiffness.

CRACKING THE DIAGNOSTIC CODE: HISTORY AND CLINICAL EXAMINATION IN LUMBAR FACET JOINT PAIN

A systematic review conducted by Maas et al.2 delved into the diagnostic accuracy of history and physical examination in identifying lumbar facet joint pain. Their findings revealed a somewhat disheartening reality. Multiple combinations of index tests and reference standards were scrutinized, often with limited data and a high risk of bias. The conclusions drawn were clear: neither history nor physical examination could reliably pinpoint a painful facet joint or reduce the necessity for diagnostic block procedures.

Gomez Vega3 and their team, on the other hand, embarked on a pilot study armed with a systematic review and consensus meetings under their belt. They honed in on 36 signs and symptoms, meticulously whittling them down to 12, including eight symptoms and four signs. The resulting diagnostic scale presented a glimmer of hope, offering a potential path to identification. However, it’s important to note that even this scale had its limitations, with varying results for different symptoms and signs.

Further studies, such as those evaluating Kemp’s test and paraspinal tenderness, continued to grapple with the challenge of accurate diagnosis. Sensitivities and specificities wavered below 50%, and historical and physical exam signs remained elusive in predicting responses to diagnostic blocks.

UNLOCKING CLARITY WITH DYNAMIC DISC MODELS: A WINDOW INTO FACET JOINT PAIN DIAGNOSIS

In the intricate puzzle of lumbar facet joint pain diagnosis, dynamic disc models emerge as a powerful key, illuminating the path to understanding for both clinicians and patients. These three-dimensional marvels offer a dynamic perspective on the spine’s inner workings, shedding light on motions, postures, and loads that might otherwise remain hidden.

**Visualizing the Culprit:** Picture a patient suffering from unilateral lower back pain that intensifies when they bend forward into flexion. Often, such experiences can lead to confusion and frustration, leaving patients seeking answers. This is where dynamic disc models come into play, transforming the abstract into the tangible. By manipulating these models into flexion demonstrating shear, clinicians can vividly demonstrate how facet joints are impacted during specific movements. When the patient witnesses the compression and irritation of a facet joint firsthand, the source of their pain becomes crystal clear. This visual revelation not only validates their experience but also fosters a deeper connection with the diagnosis.

**Treatment Clarity:** Dynamic disc models go beyond mere diagnosis; they can be instrumental in elucidating treatment strategies. For instance, a clinician can use the model to illustrate how spinal manipulation, in combination with core stability exercises, can alleviate facet joint pain. Through dynamic simulations, patients grasp the mechanics of these treatments, enhancing their confidence and compliance.

**Educational Empowerment:** Facet joint pain often carries a shroud of uncertainty. Patients might wonder if they are making their condition worse through everyday movements. Dynamic disc models provide a platform for education and empowerment. They enable patients to explore their condition, ask questions, and gain a deeper understanding of the relationship between their actions and pain. This newfound knowledge empowers them to make informed choices, reduce fear, and actively participate in their recovery.

In educating patients about their lumbar facet joint pain, dynamic disc models serve as a bridge between the intricate anatomical world and the patient’s lived experience. They demystify the condition, foster understanding, and pave the way for effective treatments.

Dynamic Disc Designs

At ddd, we create models demonstrating disc dynamics to educate the patients on the biomechanical principles of disc dynamics over a lifetime. In the case above, lumbar facet pain can be shown by showing the patient with specific motions, postures and loads that can cause pressure on facet joints. The act of shear causes translation of one vertebra on another and can be shown with a dynamic disc model demonstration. Rotation also causes facet approximation on one side while the other side can cause gapping and irritation to the capsule, for example.  Our models can help with this dynamic education connecting a patient’s symptoms with spine professional’s solutions. Explore.