facet osteoarthritis

Facet osteoarthritis pain is common and thought to be a significant contributor to back pain in the US. Within the United States, it costs 100 Billion dollars annually to combat this endemic problem. However, back pain can originate from many anatomical structures, and the facet joint is only one of them but thought by many as significant. Other common pain structures are the intervertebral discs in the case of disc bulges, disc extrusions, disc protrusions and frank nuclear sequestration. There are also more severe causes of back pain like aneurysm and other organ pathology, so it is crucial to have a professional look carefully at the diagnostics of each case.

In the case of mechanical lower back pain (others use the term non-specific lower back pain), the facet joint garners good attention. The word ‘facet’ comes from the French facette (12c., Old French facete), diminutive of face “face, appearance” and are two anatomical structures that reside behind the intervertebral disc.

Facet osteoarthritis

Modeling facet osteoarthritis is tricky because of the complexity of motion at the spinal level. The intervertebral disc height plays a role with respective facet compression because it resides on the front of the spinal motion segment. It is this compression thought to be contributing to back pain.

Clincally, facet osteoarthritis pain is often unilateral in nature

In a study conducted recently 1, researchers worked to induce facet joint arthritis by creating compression with a spring. Over time the researchers found the increased expression of interleukin‑1β and tumour necrosis factor‑α expression. In other words, with more compression elapsing over time, the more the expression of the molecules related to many low back pain patients.

This is an important study linking the mechanics of compression and the associated physiology of molecules, which are thought to be markers of back pain patients.

At Dynamic Disc Designs, we have developed models to help explain the associated compression of facet joints as it relates to disc height loss and gains. We are committed to bringing the best in modelling. Explore our website for more.

pathology & pain in Peripheral Joint

A review 1 published in Arthritis Research & Therapy decided to cover the link between subchondral bone features, pain, and structural pathology during peripheral joint OA (osteoarthritis). The review concluded that the subchondral OA bone does seem to have relevance when it comes to therapeutic measures.

The Context

According to research, OA (or osteoarthritis) is the most common form of arthritis is human beings. It leads to disability and chronic pain. Also, during the process of this review, the market didn’t necessarily have licensed DMOADs (disease-modifying osteoarthritis drugs). Take note; multiple tissues are usually involved in clinical OA. Gaining a better understanding regarding the intricate relationships that exist between these tissues and structural progression (along with the symptoms) might help with identifying potential tissue targets. The subchondral bone is of particular interest because it’s significantly associated with the hyaline cartilage.

The current review was conducted to comprehensively go over the available literature on subchondral bone structure which has been assessed using non-conventional radiographic imaging modalities. The said literature, used in this review, had examined common sites of peripheral OA as well as had described the relationships between joint replacement, structural progression, subchondral bone features, and pain.

The Method

The required original articles were found using Medline, EMBASE, and the Cochrane library databases. The articles reported an association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in the knee, hip, hand, ankle and foot OA.

A total of 2456 abstracts were screened for this review. Take note; 139 papers were included (70 of which were cross-sectional, 71 were longitudinal analyses).

The Results

The results of this review showed that there was an independent association when it came to the link between BMLs (bone marrow lesions), osteophytes and bone shape with structural progression or joint replacement. Furthermore, there was an independent association between BMLs and bone shape with longitudinal change in pain as well as incident frequent knee pain (respectively).

What was Concluded?

The review concluded that there are independent associations between subchondral bone features and structural progression, pain as well as joint replacement when peripheral OA is concerned; in the hand and hip, however, particularly in the knee. Furthermore, more in-depth research needs to be conducted to collect data about other associations (namely with the ankle and foot). Also, a better understanding of the subchondral OA bone might open doors for better therapeutic strategies.

Neck Muscles

A review 1 in the journal Spine decided to look at a particular soft tissue connection. The said connection has been stated to exist between the dura mater and neck muscles. The evidence offered by this review could help bring froth better treatment for craniocervical pain in humans as well as ensure spinal health.

What Was the Purpose of this Review?

According to data, craniocervical pain has been recorded to have a high prevalence. It’s accompanied by a lot of physical, emotional, and socioeconomic effects. However, you should know that the pathophysiology of numerous disorders that involve craniocervical pain needs to be further explored. Diagnosing a patient experiencing such pain can be quite a challenge. This is due to such disorders being possibly related to posture, muscle condition, or even the state of cerebrospinal fluid.

Different approaches have targeted the suboccipital region for treating such pathologies. Research has talked about the myodural bridge. The said bridge is the connection between the muscles and the dura mater made by soft tissue. But there’s controversy regarding the myodural bridge.

Due to such a controversial status, some researchers feel, the doors to better diagnostic and therapeutic approaches are being blocked.

The current study decided to systematically review data regarding the soft tissue bridge existing between the cervical muscles and the dura mater in the upper cervical spine.

What Was the Methodology?

The team performed a systematic search of databases including PubMed, Cochrane Library, Web of Knowledge, and PEDro. The search was conducted between the 29th and the 31st of November 2015. There were no limits on the dates.

Articles (published in French, Portuguese, English, and Spanish journals) that reported original data about the continuity of non-post-surgical soft tissues between the dura mater and cervical muscles were included. Two members from the research team independently undertook the study selection process. A third member, if required, was used for resolving potential disagreements.

The Quality Appraisal of Cadaveric Studies (or the QUACS Scale) was used to assess the methodological quality of the selected studies.

What Were the Results?

The review was able to identify a total of 479 studies. After the review’s exclusion and inclusion criteria, only 26 studies were made part of the review. A strong level of evidence was observed about there being a particular soft tissue connection present. The said connection was seen between the rectus capitis posterior minor, the rectus capitis posterior major, as well as the obliquus capitis inferior muscles.

Controversy existed surrounding the possible communication between the dura mater and the serratus posterior superior, rhomboids minor, upper trapezius, and the splenius capitis through the ligamentum nuchae. 

The team found limited evidence about the rectus capitis anterior muscle and the dura mater having a soft tissue connection.

What Was Concluded?

According to the team involved, this review offered the first systematical evidence concerning the existence of the soft tissue connection present between the cervical dura mater and neck muscles. More research focusing on this particular connection could help create effective therapeutic and pathophysiological measures to better address craniocervical disorders as well as spinal health issues.

Mechanoreceptors in the Lumbar Spine’s

A study 1 published in the ‘Journal of Clinical Neuroscience’ decided to analyze mechanoreceptors present in the lumbar spine’s intervertebral discs. With such receptors linked to Low Back Pain, the study presented certain conclusive results.

What Was the Context?

Low back pain or LBP has been observed to impact people around the globe. Such ailment effects a person’s social, financial, physical, and psychological wellbeing. Research continues to create therapies to address LBP. When talking about such a condition, the nerve structures present in the intervertebral discs can’t be ignored. 

Intense muscle spasm of the vertebral musculature is an important component of LBP, elicited through reflex arches mediated by specialized nerve endings. Joint receptors have been classified into four categories. 

Type 1 is encapsulated mechanoreceptors with similarity to Ruffini endings. Type II are encapsulated mechanoreceptors that are similar to Pacinian corpuscles. Type III are encapsulated mechanoreceptors that share similarity to Golgi endings. And Type IV are unmyelinated free nerve endings as well as non-encapsulated plexuses that have nociceptive function.

While mechanoreceptors present in the human intervertebral disc have been studied, there is limited data available.

The objective of the current study was to help determine the different types of mechanoreceptors present in the two lower intervertebral discs. A review of available literature was also part of this study.

What Was the Methodology?

The current study involved a total of 25 intervertebral discs being removed during routine autopsy from a total of 15 human cadavers. The team only harvested the L4-L5 (13 discs) along with L5-S1 (12 discs). From the cadavers, 8 were male, while 7 were female. The mean age of the selected cadavers was 45.4 years from a range of 15-66 years.

Take note; none of the cadavers had a history of chronic LBP or underwent an operation on their vertebral column. Upon visual inspection, all of the specimens were deemed normal. Also, autopsy specimens were removed within 6 hours after death.

The discs’ anterior and posterior halves were dissected at the midsubstance between the endplates. Everything was studied separately. 

The team evaluated the degree of disc degeneration by using a semi-quantitative method. The morphologic criteria of Freeman and Wyke was used to distinguish the different receptors. A quantitative analysis was also performed for determining the mechanoreceptor’s density in each disc section.

A comparison was made through Fisher’s exact test. The Kruskal-Wallis test was administered to record the age comparison among the mechanoreceptor groups. Statistical analysis was conducted by using SPSS version 12.

What Were the Results?

According to the results, the team couldn’t find nerve structures in 2 of the 25 disc samples. The mean density of receptors per disc was 1.4 in the discs having Ruffini receptors. The density of Golgi receptors was 1.2, while it was 1.3 for free nerve fibers in each specimen. Take note; Pacinian receptors weren’t identified in the samples.

A significant association was seen between the type and level of mechanoreceptor present when observing the disc tissue’s anterior part. Discs with Golgi and Ruffini-type receptors were analyzed to be more frequent (around 78%) at the L5-S1 level. Also, a statistically significant difference wasn’t observed between the (type and frequency) of receptors and the sex, age, and degree of disc degeneration.  

Furthermore, the receptors that showed up a lot showed morphology similar to the Ruffini receptor. The second most frequency of corpuscular receptors showed similarities to the Golgi tendon organ. Free nerve fibers were another frequent finding.

What Was Concluded?

The current study confirmed the existence of an abundant network of non-encapsulated and encapsulated receptors in the human lower lumbar spine’s intervertebral discs.

According to data, it has been assumed that the primary role of encapsulated structures is the continuous monitoring of position, acceleration, and velocity. As for free nerve fibers, they are likely involved in nociception or regulation of vessel tone.

Through the results of this study, one can see that further research is required to better understand mechanoreceptors to aid with effectively addressing LBP and related ailments.

Shoulder and Cervical Spine Pain

An interesting review 1 in the ‘American Journal of Medicine’ focused on the challenge when it came to differentiating between the cause of cervical spine and shoulder pain. It presented an evidence-based approach to address such a clinical situation.


Why Was Such a Review Conducted?

Trying to differentiate the origin of pain as well as dysfunction because of cervical pain and shoulder pathology has presented itself as a tough clinical challenge when dealing with numerous patients. A practitioner might be misled due to what the patient reports as the anatomic region where the pain is being experienced.

For such patients to be successfully treated, there needs to be a complete history and physical examination as well as the administration of the appropriate provocative maneuvers. 

Furthermore, it’s essential to have an evidence-based selection of clinical testing, which should be customized to the most likely underlying cause. The current study set out to present an evidence-based review of the common reasons behind neck and shoulder pain. Another objective was to offer guidelines to help identify the pain generator in challenging cases.

Patient Evaluation – Shoulder

According to the review, a thorough history and physical examination are a must for beginning patient evaluations. Diagnostic testing should be done depending on the examination findings.

Talking about the shoulder, recording history includes patient demographics to cover factors such as age, gender, presence of any psychosocial and medical condition, mechanism of injury, hand dominance, and such. By using a patient’s history, pain can be characterized to learn about the pain’s quality, relieving as well as aggravating factors, and progression.

Take note; dull and aching pain is seen more in shoulder pathology, while a burning or electric type pain is usually a determining factor for cervical spine or neurologic origin.

Also, shoulder pathology is commonly related to painful arm abduction. However, patients with cervical radiculopathy might experience symptom relief due to arm abduction.

The review shared that pain experienced directly over the lateral deltoid region could indicate subacromial or intrinsic glenohumeral pathology. Similarly, pain that’s localized directly over the acromioclavicular joint may indicate acromioclavicular joint pathology.

Also, shoulder pathology is commonly related to nighttime aching and sleep disturbance. According to data, patients with rotator cuff tears exhibited sleep disturbance in up to 90% of cases. 

Other than that, weakness of the shoulder while in the absence of pain should raise concern for nerve impingement.

Patient Evaluation – Cervical Spine

According to the review, pain is commonly produced (by cervical radiculopathy) around the shoulder girdle’s later portion. Patients with such a condition do report a disturbance in their sensory and strength levels starting in their neck and moving to the upper extremity.

Arm pain is reported by more than 90% of cervical radiculopathy cases.

Furthermore, data has stated that cervical radiculopathy has an infrequent association with trauma.

Clinicians could suspect cervical myelopathy or myeloradiculopathy because of shoulder or neck pain with painless loss of hand dexterity or an uncomfortable gait or even a lack of bowel or bladder control.

Cases with Positive Provocative Shoulder Testing

In a typical case of a patient with shoulder pain with positive provocative shoulder testing, plain radiographs can be used as an initial test.

If pain radiography ends up being non-diagnostic, further testing can be done based on the presumed diagnosis. MRI and ultrasound can be used if an underlying rotator cuff tear has been suspected.

In complex cases, positive provocative shoulder testing results might be demonstrated by patients having cervical pain. A diagnostic subacromial injection can be used for provocative impingement testing as well as primary cervical pain.

Cases with Positive Provocative Cervical Spine Testing

Coming to cases with classic radiculopathy pain along with a positive Spurling test, a standard AP and lateral cervical radiographs can be used. If radiculopathy has been suspected, MRI is deemed an appropriate test. If an MRI isn’t feasible, CT myelography may be used.

EMG or electromyography has also been used when the MRI or CT are considered inconclusive. However, EMG is controversial when used as a follow-up test for radiculopathy. Selective nerve root injections are also an option.

Positive Provocative Shoulder and Cervical Spine Testing

In cases having evidence of both cervical spine and shoulder pathology on advanced imaging, focusing on the shoulder first has been considered effective.

Negative Provocative Shoulder and Cervical Spine Testing

False-positives and useless treatment strategies might be produced in cases showing an absence of specific provocative findings in the cervical spine or shoulder. In such instances, it’s recommended to opt for nonsurgical management along with physical therapy meant to address periscapular and neck pain.

What Was Concluded?

The current review concluded that in cases with a complex clinical history or displaying a complex mix of shoulder and neck pain, differentiating between a cervical spine vs. shoulder cause is challenging.

The first step is to rely on data from a thorough physical and history examination along with the necessary provocative maneuvers. Appropriate follow-up imaging should be selected. EMG and selective injections are deemed useful when advanced imaging is inconclusive. 

The health provider needs to understand the intricacies and overlapping of pain and dysfunction resulting from shoulder and cervical spine disorders. Both should be considered when evaluating a patient to help come up with a suitable treatment plan.

A review 1 in the European Spine Journal went over the treatments available for Lumbar Disc Herniation (LDH) in children and adolescents. The review shared which treatment showed the best results.

Why Conduct Such a Review?

Research has shared that LDH or lumbar disc herniation, while affecting adults, also impacted children as well as adolescents (pediatric LDH). It is important to note that pediatric LDH has a number of distinctive features due to the physiological natures of children and adolescents being unique.

Due to adult Lumbar Disc Herniation getting a lot of focus, there’s still a lot that needs to be understood about pediatric LDH. One of the areas involves the treatment available for such LDH and the possible effects of such treatments.

The current review study was conducted to help present an in-depth look at treatments for pediatric LDH and what they entail.

What Was the Methodology?

The searching strategy involved a literature search using electronic databases such as PUBMED and EMBASE. MeSH terminologies (adolescent, child, intervertebral disc displacement, and treatment outcome) and keywords (LDH, adolescent, and child) were used. There were no limitations applied.

The inclusion criteria involved articles featuring relevant information about LDH in adolescents and children. Related references were included, too. The clinical outcome in the articles was assessed, too. 

Take note; case series that didn’t feature a detailed description of the outcome were excluded. Also, case series involving patients over 21-years-of-age were excluded as well. The age-specific exclusion was because previous research demonstrated the human body had almost reached completion of growth during that time.

In the end, 44 series and a total of 8 case reports (with 1,664 cases) were included in the current review. All of the included articles fell in the 1945 to 2008 timeframe.

What Was Observed?

The review shared that LDH is quite a common disorder among adults. The frequency is believed to be much lower in children and adolescents. In all patients hospitalized for LDH, only 0.5-6.8% of the cases were reported as being pediatric patients.

Pediatric LDH is said to be caused by several potential factors. Self-reported or sport-related injury is considered to be the most common cause. This was because 30-60% of adolescents and children experiencing symptomatic LDH were reported to have a history of trauma before pain occurred. However, adult cases usually didn’t report a traumatic experience before the onset of symptoms.

Some recent studies have suggested trauma being an inciting factor that exacerbated pre-existing lesion in discs.

Another factor is considered to be genetics. It has been reported that 13-57% of adolescents with LDH have a first-degree relative with the same condition.

Looking at it from a clinical perspective, pediatric LDH clinically presents itself similarly to adult LDH. Take note; a distinctive feature is that up to 90% of the patients demonstrated a positive straight-leg raising test. 

This can be explained by the fact the nerve root tension is greater in children and adolescents. Also, adolescents and children had a lower chance of presenting neurological symptoms (including weakness and numbness).

What Were the Treatments?

Coming to the treatment part of the review, there’s Conservative treatment, Intradiscal therapy, and Surgical treatment.

Breaking it down, Conservative treatment for pediatric LDH included physical therapy, bed rest, analgesic and anti-inflammatory agents, and limiting physical activity.

As for Intradiscal therapy, chemonucleolysis was the only type being administered for adolescents and children.

Surgical treatment for pediatric LDH was recommended for pediatric LDH on a case-by-case basis. Percutaneous endoscopic discectomy or PED and Microsurgical discectomy or MD were involved.

What Was Concluded?

The review concluded that the diagnosis for adult and pediatric LDH remained similar. As for the treatment, Conservative methods have been reported to be less effective for pediatric LDH when compared to being used for adults. However, Conservative treatment remained the go-to for pediatric LDH cases.

If the said treatment failed, certain patients could be moved to Chemonucleolysis. Excellent short-term outcomes were reported when pediatric LDH was treated surgically (regardless of the modality). Take note; the outcome decreased during the mid-term follow-up, yet it’s considered effective for the long run.

Except for a few exceptions, Spinal fusion isn’t recommended for pediatric LDH.

The review also reported that pediatric LDH could occur in 10-year-olds and younger, with surgical treatments offering positive results.

From this review, one can realize the need to conduct more research involving pediatric LDH for improving treatments and being ready to address any post-treatment related issues.

Crack Propagation Osteoarthritis

Osteoarthritis is common and causes much disability in the world to many. It is a joint condition that causes pain, which often leads people to seek therapy. Despite the efforts to learn the underlying causes, researchers have been confused as to the source and propagation of degenerative osteoarthritic changes. We know that surface injury to cartilage can occur from high-risk competitive sports and result in the development of osteoarthritis; the precise reasons as to this has eluded researchers in the field. Understanding the mechanobiology of the early stages of OA when micro-cracks start will be an important piece of the puzzle in the prevention of osteoarthritis.

Just this month, a group of researchers out of the University of Calgary, looked at the finer micro-structure of the cartilage. 1 They looked at crack propagation (micro-fracturing) of the cartilage to get a better understanding of the load and respective magnitude as it relates to the damage. Their objective included looking carefully at the local strain distribution of the cartilage nearby to the microcracks.

What did they do?

Cylindrical osteochondral punch plugs were harvested from pig knees and fixed to a custom design compression testing device. The cartilage thickness was measured at three different locations of the surface. To prevent dehydration, which can often occur in these testing environments and affect the results, they fully immersed the sample in a phosphate-buffered solution. The thickness of the cartilage was measured using light microscopy. Measures of strain were applied. To simulate the crack in the cartilage found in-vivo, vertical cuts were made in the cartilage at the most superficial part of the surface cartilage along with the middle zone.

What did they find out?

Axial strains were significantly more abundant at the damage zone compared to the non-damaged cartilage. This indicates that the ability of the cartilage to resist compression is less in the damaged or micro fractured cartilage, disrupting the biomechanics.

Crack Propagation Osteoarthritis


What can we take away from this study?

The drive to learn about osteoarthritis is essential. Billions of dollars are spent annually for a multitude of therapeutics, including joint replacement, injections, pharmaceuticals and manual therapy. By learning about how cracks propagate in the cartilage and, ultimately, how we prevent the development of osteoarthritis will be a great asset to the planet.

At Dynamic Disc Designs, we work to follow the research and work to bring that to the doctor-patient engagement process. Our latest modelling now includes a crack in the cartilage of the facet joint.