Why is Subchondral Bone Density Higher in People with Low Back Pain

A very recent study from September 2019, 1 published in the journal Skeletal Radiology, brought forward an interesting conclusion related to Low Back Pain or LBP. The results showed that the subchondral bone density was higher in people with LBP.

What was the Context?

According to years of data, LBP happens to be the second most common adult-disability around the world, with the lifetime prevalence being 54-80%. It leads to sociological, economic, and psychological stress. The causes behind LBP include facet joint osteoarthritis (OA), disc degeneration, soft tissue sprain, nerve impingement, instability, infection, and neoplasm. Being more specific, OA of the facet joints (the load-bearing joints of the posterior spine), is considered as the reason of LBP in 15–45% of patients.

Take note; long-term changes in the bone’s mechanical loading alters its microstructure. An increase in the mineral density of the subchondral bone has been observed due to loading on the joint’s subchondral surface. Such a change has been seen in joints of the upper and lower extremities as well as in the joints of the spine.

What Did the Current Study Do?

Apparently, not a lot of research has been conducted for analyzing such changes with a focus on the loading patterns of facet joint and its relation to LBP as well as how the subchondral bone is involved.

The current study had two objectives. It aimed to test the hypothesis that LBP is associated with the density of the lumbar facet subchondral bone. Other than that, it was to use computed tomography osteo absorptiometry to analyze the distribution of the subchondral bone density in the facet joint. The study wanted to better understand the loading pattern of the lumbar spine’s facet joints.

facet joint

The Design

The current research involved 89 volunteers. From them, a total of 33 were recruited as subjects that also had LBP, and a total of 56 were subjects with no LBP. The males were 47, with the females being 42. The mean age came in at 36.5 years.

All of the subjects went through lumber computed tomography (CT) scans. 3D joint surface models were created of each facet joint as well as the subchondral bone density underneath every facet joint surface.

This study used linear interpolation of the HU (Hounsfield units) at four adjacent pixels in each of the CT slice. Furthermore, ANOVA with post hoc Fisher pairwise comparisons was used for testing the association of subchondral bone density with lumbar levels, facet zones, subject gender, and patient age.

What Did the Results Show?

The results presented that subchondral bone density was observed to be the greatest in subjects with LBP as well as female and younger subjects. It was also highest in the superior facets, the center zone of the facets as well as the upper lumbar levels.

Also, it was lowest in subjects that didn’t have LBP, the male subjects, and older subjects. It was also lowest in the caudal zone of the facets, the lower lumbar levels, and the inferior facets.

What Was Concluded?

According to the present study, the data showed the differences present in the subchondral bone density when analyzing subjects with or without LBP. Furthermore, one can see how a higher density in subjects with LBP might be related to an increase in load-bearing because of the degeneration of the lumbar discs or perhaps due to the load’s abnormal distribution in the joint because of the joint’s articular cartilage being degenerated.

The current data hopes it can help others better understand the loading patterns of joints and the associated biomechanical properties.

Does Biomechanics Research Hold the Answer to Effective Low Back Pain Treatment

Studies have shown biomechanics playing a role in LBP or Low Back Pain development. It’s even considered to have links to the persistent and (or) recurrent nature of LBP. However, there’s still debate related to whether biomechanics (on its own) can offer the basis of intervention. A viewpoint-counterpoint debate 1 in the Journal of Orthopedic & Sports Physical Therapy set out to answer some questions.

Why Focus on Biomechanics?

Biomechanics is a term that relates to the mechanics of the human body. This includes the body’s neuromuscular control. Numerous studies about LBP have focused on such an area. With the issue of LBP being bio-psycho-social in nature, some believe that LBP research particularly focusing on Biomechanics may have the answers to effective LBP treatments.

The current commentary has considered whether there’s any potential in the field of biomechanics research for advancements in LBP treatment strategies. With LBP being experienced by millions of people around the globe, finding effective treatments should be a priority.

Addressing Both Sides

The current commentary has used a viewpoint-counter viewpoint format to look at both sides of the biomechanics and LBP related argument. Such a format has allowed it to be different than perspectives that only approach biomechanics.

Delaminated Circumferential

What more did it do?

Along with the viewpoint-counter viewpoint format, this commentary also described models that place a lot of emphasis on biomechanical factors. Furthermore, the reactions to specific viewpoints have been displayed as foundations for future clinical practice and research to better understand the potential of biomechanics in mapping LBP treatment.

What Was Concluded?

The commentary concluded that authors of the ‘counterpoint’ as well as ‘viewpoint positions’ agree about chronic non-specific LBP having bio-psycho-socio components that vary depending on individual experiences. They also agreed that biomechanics plays a role in such development. However, none of the biomechanical models could present a valid argument that it alone should be the focus of Low Back Pain Treatment. There’s a lot of potential in a bio-psycho-socio approach that includes biomechanics.

Do Transient Effects of Sleep Impact Next-Day Pain and Fatigue Experienced by Older Adults with Symptomatic Osteoarthritis

Research has shown that poor quality of sleep is associated with higher rates of pain and fatigue in people dealing with OA (osteoarthritis). The current study 1, in the Journal of Pain, was conducted to determine whether or not sleep impacted the diurnal pattern of next-day pain and fatigue associated with OA. The results showed that good sleep was linked to lower pain and fatigue on awakening. However, the benefit dissipated as the day went by.

The Context

As mentioned, older adults with OA tend to commonly experience pain and fatigue because of poor quality of sleep. More research is still required to examine the influence of nocturnal sleep on pain and fatigue throughout the day.

Understanding such mechanics might prove to be beneficial when dealing with older patients with OA and helping them improve their quality of life.

Pain and Fatigue

The Study

The aim of the current study was to observe the links between self-reported sleep quality and sleep parameters with pain and fatigue experienced through the following day. The study used data covering five consecutive days from older adults with hip and/or knee OA.

The study’s objective was to investigate sleep’s association with diurnal changes in fatigue and pain. The study was conducted to answer whether or not specific times of the day existed during which symptoms are more vulnerable to the effects of poor sleep.

The study included 160 participants (adults aged 65 years and above). People with clinically important levels of fatigue were recruited.

The Western Ontario and McMaster Universities Arthritis Index (WOMAC) five-item pain subscale was used to measure pain intensity. Fatigue was measured, for this study, using the Brief Fatigue Inventory (BFI). Sleep was assessed each morning. Pain intensity and fatigue were assessed five times a day.

Using the Actiwatch-Score, the sleep intervals were established through corroborating self-report of lights off and wake-up times with actigraphy activity counts.

Stata was used for analysis.

Pain and Fatigue disc model

What was Concluded?

The results of the current (sleep quality and OA) study helped conclude that diurnal patterns were demonstrated by pain and fatigue. A good night’s sleep showed significantly lower symptoms in the morning. Good sleep had a significant impact on fatigue compared to pain intensity. A poor night’s sleep was linked to an increase in pain intensity in the morning (though it dissipated as the day progressed). However, more research (with a higher sample size and diversity) was needed to determine any future clinical benefits.

 

Does the Human Body Hold Potential for Improved Regeneration

A recent study 1 from the journal Science Advances analyzed protein turnover that occurs in articular cartilage from lower limb joints in humans. The results showed a potential for regeneration that could likely be exploited to improve joint repair.

What was the Context?

While regeneration exists in certain animal species, humans are believed not to have the ability to counter cumulative damage. In this context, the said type of damage is caused by repetitive joint use as well as certain injuries due to which cartilage breaks down and gives rise to osteoarthritis (OA). According to previous research, the turnover of insoluble collagen in human adult cartilage has been suggested to be quite limited. However, take note, humans do have the limited regenerative capacity. For example, during childhood, the regrowth of distal portions of amputated digits has been observed.

miRNA has been observed to play a significant role in regeneration; however, miRNA’s regenerative role is low in humans. The current study set out to explore the articular cartilage’s protein turnover (in the human lower limb joints).

The Design

The current study collected articular cartilage (as waste surgical specimens) from Duke University Hospital. The full-thickness cartilage was collected from the hip, knee, and ankle joints from patients that had end-stage OA who had undergone total arthroplasty surgery. Take note; the cartilage was from the perilesional regions of the hip, knee, and ankle joint’s load-bearing area.

A total of 18 samples were collected. The samples included three types of joints (hip, knee, and ankle), two types of disease state (healthy as well as OA), and three biological replicates of each type with matched age range. The mean age of healthy non-OA patients was 58.8 years. Their age range was 30 to 82 years. Also, the mean age of the patients with OA was 59.8 years (with the range being 42 and 87 years).

The analysis was performed on a quadrupole Orbitrap benchtop mass spectrometer (Q Exactive) equipped with an EASY-nLC 1000 system. Furthermore, protein identification was performed using the Homo sapiens taxonomy) setting of the Swiss-Prot database with Proteome Discoverer 2.1.

Also, miRNA quantification was done by a real-time polymerase chain reaction. The Deamidation rate was analyzed using the Swiss-PdbViewer.

What were the Results?

The study demonstrated a position-dependent gradient (distal high, proximal low) of protein turnover in human lower limb cartilage. The findings of this study have helped reveal a dynamic anabolic effect in human limbs that showcase a potential (limited) natural regenerative capacity in human cartilage.

According to these results, increased expression of matrix proteins is seen in OA knee cartilage. Also, the higher prevalence of hip and knee OA (compared to ankle OA), might explain the lack of repair in proximal joints.

What was Concluded?

The results suggested the role of regenerative miRNA present in cartilage homeostasis, intrinsic repair capacity, and turnover. Also, the limited regenerative capacity in humans is proposed to be primarily controlled by location rather than the shape of the joint or loading. The use of in vivo protein deamidation molecular clocks helped find a distal-proximal gradient of protein turnover.

The current data also suggested that anabolic treatments may be required in addition to anticatabolic treatments, especially for human hip joints, to prevent or, at least, slow OA’s rate of progression.

The study concluded that more functional studies on the effects of these associated miRNAs would be required to further reveal their regulatory role in cartilage repair and to help prevent certain ailments (including Low Back Pain).

Interestingly, the study suggested that injection of key regenerative miRNA in a joint (either singly or in combination) might have the potential to improve endogenous repair and help resist the degeneration of joint tissues in all types of arthritis.

 

Can Verbal Suggestions Manage Musculoskeletal Pain A Review

How much of an impact do verbal suggestions have on managing pain? We can’t be entirely sure. There has been a lot of controversy surrounding the power of suggestion and pain management. A review 1, in the journal of Physical Therapy Reviews, was conducted to find some answers. While there is potential in such a field, more research is required to see any clinical significance associated with pain management and verbal suggestions.

What’s the Context?

Numerous studies prove that pain has socioeconomic and health implications. This includes disability and functional limitation. Chronic lumbar pain has been observed to have the greatest prevalence. Low Back Pain or LBP is an economically draining ailment for individuals around the globe. Furthermore, reduction in pain due to surgeries and other LBP treatments isn’t always accompanied by improvement. Due to LBP being multi-faceted (including psychological factors), a person’s psyche has been suggested to help with recovery. So, verbal suggestions might have a role to play in the treatment of LBP.

Musculoskeletal lower back pain

The Purpose of This Review

The aim of the current review was to describe as well as explore the neurobiological mechanisms associated with verbal suggestions when it came to managing musculoskeletal pain in patients.

The literature search was conducted by two independent reviewers. The databases included were PEDro databases, Medline, Cochrane Library, Lilacs. Systematic reviews, randomized clinical trials, and literature reviews were included in this review.

After the study’s exclusion criteria, a total of 13 studies were involved in the current review. The total included four randomized controlled trials and nine reviews. The current review covered the neurobiology of verbal suggestion, and the effects of verbal suggestion in pain sufferers.

What did the Review Conclude?

The review concluded that there’s potential in positive verbal suggestion to improve the effectiveness of LBP management in patients. The review pointed out that such suggestions could generate hypoalgesia via the placebo effect. However, more research is required to fully determine the clinical significance of verbal suggestions for pain management in patients.

Can Hypersensitivity Be Decreased in Patients of Chronic Whiplash after a Medial Branch Block Procedure

A study 1, in the BMC Musculoskeletal Disorders, was conducted to determine if there was any change in sensory hypersensitivity in patients of chronic whiplash disorders after a medial branch block procedure in the cervical spine. The results showed a decrease in the patient’s pain.

What’s the Context?

It’s common for motor vehicle collision (MVC) to result in cervical spine pain and dysfunction. While many are able to recover (significantly) from neck pain and disability in about six months or even a year, reports show that 32% to 56% of patients continue to suffer.

According to studies, the cervical zygapophyseal joints are known to be a primary source of pain in as many as 60% of people who experience WAD or whiplash associated disorders. Such joints may also be playing a role in peripheral and centrally mediated pain (sensory hypersensitivity).

The Study

The current study was conducted to determine any change in sensory hypersensitivity in WAD grade II patients after a medial brank block (or MBB) procedure in their cervical spine.

This exploratory study utilized a pretest-posttest design. Eighteen participants (3 males, and 15 females) with whiplash associated disorders grade II, and 18 healthy (matches gender breakdown) participants were involved in this study. Take note, patients with chronic WAD and aged 18 to 60 years, who reported neck pain for more than 6 months, and who experienced a minimum of 80% decrease in the said neck pain after an intra-articular zygapophyseal joint block procedure were included.

zygapophyseal joints

The study used a single item Numeric Pain Rating Scale (0-10) for measuring the cervical spine pain intensity of patients before as well as after the MBB procedure.

Quantitative sensory testing (QST), which considered pressure pain thresholds (PPTs’) and cold pain thresholds (CPT’s), was used to measure sensory hypersensitivity. In patients dealing with WAD, the measures were taken at three sites bilaterally, pre and post-MBB. The study used an independent and dependent t-test to determine differences between thresholds.

The Results

The study revealed that, at baseline, the PPT’s were decreased at all three sites in the WAD group. The cervical spine had an increase of cold pain thresholds in the WAD group. Significant increases in PPT’s at all sites was observed in the WAD group (post-MBB), along with a substantial decrease in CPT’s at the cervical spine.

What was Concluded?

The study concluded that chronic WAD patients showed evidence of widespread sensory hypersensitivity in the presence of thermal or mechanical stimuli. Decreased levels of sensory hypersensitivity were observed in the WAD group after the decrease in the primary source of pain caused by the cervical zygapophyseal joints.

However, the study did note that large clinical trials, addressing long-term follow-up interventions targeted at eliminating or reducing the source of cervical pain in WAD patients, were required.

Assessing the Relationship Between Biomechanical Instability and Degenerative Changes in the Lumbar Spine in CLBP Patients

There still seems to be some controversy when it comes to addressing the relationship between biomechanical instability and the degenerative changes in the lumbar spine in CLBP (chronic lower back pain) patients. A study 1 decided to gather more data about it.

Why such a focus?

Chronic low back pain or CLBP may be caused by the biomechanical instability following degenerative changes in the lumbar spine. Low back pain is experienced by millions of people around the globe. The course of clinical treatment for such an issue can be guided through radiographical assessment. Such an assessment would be of the bending motions of the lumbar spine as it might aid with the identification of the absence or presence of biomechanical instability in patients with CLBP.

Lumbar spine

Due to the said controversy, this study decided to look into the relationship between biomechanical instability and degree of degenerative changes in the lumbar spine in CLBP patients. Being a retrospective radiographical study, it focused on evaluating the changes in kinematics at various lumbar levels (the L5-S1 level, in particular) with progressive grades of disc degeneration as well as facet joint osteoarthritis in CLBP patients.

The Study

The current study involved 72 (51 males and 21 females) consecutive CLBP patients. The age range of the participants was kept 18 to 70 years.

It used standing neutral and dynamic flexion/extension (Fx/Ex) radiographs of the lumbar spine to evaluate the in vivo segmental kinematics at the L1-L2 through L5-L1. Changes in signal intensity and central disc height on mid-sagittal T2-weight MR (magnetic resonance) scans were used to quantify disc degeneration.

What were the Results?

The study shared that disc degeneration and facet joint osteoarthritis was able to occur independently of each other at the L5-L1 level. However, an association was observed at the L4-L5 as well as the L3-L4 levels. A greater range of motion in Ex and a smaller range of motion in Fx was observed in the absence of facet joint osteoarthritis (when compared to the upper lumbar levels). No change in the L5-L1 kinematics was observed with progressive disc degeneration in the absence of facet joint osteoarthritis. However, in the presence of such osteoarthritis, re-stabilization of the L5-L1 segment was observed between the severe and mild disc degeneration states.

 

Assessing the Relationship Between Biomechanical Instability and Degenerative Changes

The Conclusion

The study concluded that unique degenerative and kinematic characteristics were exhibited by the L5-S1 motion segment compared with the upper lumbar motion segments. Furthermore, at the L5-S1 level, facet joint osteoarthritis and disc degeneration occurred independently of each other. The L5-S1 motion segment was biomechanically re-stabilized by severe disc degeneration if facet joint osteoarthritis was present.

What does it mean?

The study shared that the L5-S1 level, due to having unique anatomical features, may play a significant role in re-stabilizing the level with severe degeneration of the disc and facet joints. The data will prove beneficial in understanding more about CLBP and its clinical treatments.