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13 Articles in Volume 18, Issue #1
Applying a Collaborative Care Model to the Treatment of Chronic Pain and Depression
Assessing the Pain Triangle
Emerging Technologies in Rehabilitation Medicine
Gaming as a Tool for Pain Relief
Honoring Dr. Forest Tennant’s 50-Plus Years in Pain Management
Is There a Chronic Pain Personality Profile?
Managing Musculoskeletal Pain in Endurance Athletes
Managing Perioperative Pain
Nonparenteral Oxytocin, Erythromelalgia...Letters from the Minds of Peers and Patients
OSKA PEMF Pain Relief Device: A Mini Review Trial
Patient Communication & Opioid Prescribing in the New Year
What Opioid Shopping Means for Pain Practitioners
Would Patients Benefit from a Glucosamine/Chondroitin Supplement to Manage Knee Osteoarthritis Pain?

Emerging Technologies in Rehabilitation Medicine

The impact of evolving surgical approaches on the postoperative treatment of joint restoration, scarring, pain, and swelling.

Injury, disease, and aging may all lead to the necessity for surgery at some point in a person’s life. Musculoskeletal surgeries to the lower extremities, in particular, may lead to a variety of pain-related conditions, including: scarring/fibrosing, effusion (swelling), soft tissue atrophy, reduced stamina and mobility, decreased flexibility and active range of motion, gait/balance deficits, and an overall functional decline stemming primarily from pain and inflammation. Pain and inflammation may further lead to arthrogenic inhibition, which may short-circuit functional mobility.

A healthy musculoskeletal system is required for optimal mobility and function, including strength, power, endurance, flexibility, stability, and balance. In a finely tuned nervous and muscular system, these two systems coordinate (known as neuromuscular integration) to form the basis of general motor control, which is governed by both brain and spinal cord-mediated activities. Physical medicine and rehabilitation (PM&R) providers are faced with restoring this integration in the postsurgical setting.

Practical Pain Management previously featured technology trends in rehabilitation medicine, with a focus on electrotherapy devices. This report casts a broader net to look at how rehabilitation technology is evolving to reflect changes in surgical techniques that have emerged or are in the pipeline. Specifically, new-generation knee, hip, shoulder, and lower spine procedures are addressed, with postoperative approaches for related joint instability, scarring, pain, and swelling.

Innovative Surgical Approaches

Today’s orthopedic surgeons have responded to the growing need for longevity and quality of life with innovative surgical techniques that aim to minimize invasiveness to both spare tissue and to reduce rehabilitation time after a procedure. Below are examples of cutting-edge surgical procedures that demonstrate improved patient outcomes. The section that follows offers a discussion of how PM&R professionals may aid in recovery efforts.

Resurfacing Versus Replacement for the Knee and Hip

Over the past 20 years, knee and hip replacement surgeries increasingly have been followed by later-life ankle and shoulder replacement procedures. Full prosthetic replacements were previously the norm, providing, for the most part, enhanced quality of life with few postoperative complications.1 The most common complications were prosthesis failure in the hip2 and arthrofibrosis in the knees,3 a complication that is not necessarily the fault of the surgeon or therapist, and one which has been linked more closely to collagen metabolism.4 Nonetheless, arthroplasty, or full joint replacement, is invasive and may inevitably lead to significant pain and inflammation, necessitating some level of post-surgical physical therapy and pain management.

As we approach the year 2020, candidates for hip and knee replacement, as well as younger prospective patients between the ages of 40 and 55, now have an option for joint restoration through the use of minimally invasive techniques that not only offer similar benefits, but also provide potential advantages, including bone and tissue sparing.5 This newer generation of mobility enhancing orthopedic surgeries—known as resurfacing—are more similar to partial joint replacements, but devoid of bulky prosthetic ball and sockets. Resurfacing provides patients with a new liner (articulating surface) for a joint that has degenerated with time and wear. One example, approved by the FDA in 2011, is the ConforMIS system (Billerica, MA), which promises a fresh, custom-fit, articulating surface for the knee patient.6 The ConforMIS is essentially a patient-specific implant that acts to provide a new articulating surface for a severely worn-out joint. Its original unicompartmental design has evolved to provide bicompartmental capability, which makes it a viable option for total joint replacement.

Another resurfacing option known as the MAKOplasty procedure, approved in 2012, uses a minimally invasive robotic arm (MAKO Surgical Corp, Stryker, Kalamazoo, MI)7 (see Figure 1). The robotic-assisted technology includes 3D imaging, allowing the implant to be seated with precision and custom fit. As a result, problems related to prosthetic device overhang or under-hang are minimized and/or eliminated. A pre-operative set of CT scans may be loaded into the operating software, which then creates a patient-specific template for the surgery. This procedure may be used in painful hip and unicompartmental knee problems as in the case of severe osteoarthritis of the joint.

Hip resurfacing may appeal to younger patients who wish to remain active and only have a small area of exposed (bone-on-bone) joint destruction. A MAKOplasty procedure may enable a surgeon to remove a few millimeters of damaged hyaline cartilage, sparing bone as well as surrounding soft and boney tissue. This less-invasive procedure may result in lower costs and reduced postoperative disability.

Resurfacing procedures, in comparison to arthroplasty, do not require primary stabilizing structures, such as the anterior and posterior cruciate ligaments. As a result, this approach may be more appealing to the aging demographic that places a premium on functional mobility.

Reverse vs Traditional Arthroplasty for the Shoulder

Reverse shoulder arthroplasty (RSA) procedures, approved by FDA in 2003, are also being performed more often by orthopedic surgeons rather than traditional shoulder replacement. The newer procedure is preferred when cuff tear arthropathy (ie, large to massive rotator cuff rupture) is detected. If there is little chance of preserving the cuff musculature, an RSA method may be preferred in order to enable the deltoid muscle to take over as the dominant stabilizer of the shoulder. In RSA, the ball and socket components are switched so the metal ball is placed where the glenoid fossa is typically located, and a plastic socket is attached to the proximal upper part of the humerus (see Figure 2). While RSA does not replace traditional arthroplasty, it may provide an additional option for the patient afflicted by a severely damaged shoulder.

Artificial Discs for the Spine

Another procedure changing the surgical landscape and challenging rehabilitation professionals is synthetic or artificial disc replacement, which was developed to overcome the shortcomings of interbody fusion procedures.8 This type of surgery is still controversial as it is in its infancy in the United States, emerging in 2006, where as the procedure has been performed across Europe for the past 25 or more years, with respect to the treatment of degenerative disc disease in particular.9

From a patient outcome standpoint, fusion procedures may limit mobility significantly and there is often a trade-off between stability and mobility. It is common for a fusion patient to continue to experience pain and tightness after spinal surgery, regardless of the type (eg, disc replacement, decompression, fusion, and even microdiscectomy).6,7

Some potential benefits of artificial discs include increased motion/movement, faster recovery than a fusion, restoration of proper spinal biomechanics, and decreased pain. Contraindications may include obesity, osteoporosis, and prior abdominal surgeries. Risks related to artificial disc surgery include infection, injury, and sexual dysfunction due to possible nerve damage.

Evolving Rehabilitation Techniques

As the aforementioned surgical approaches grow in preference, rehabilitation providers must respond to some new, unique challenges in the recovery period. Although the above examples of new-generation procedures may reduce tissue disruption and invasiveness, a patient’s strength, stability, and mobility will still need to be re-established. Below is a look at emerging therapy interventions and tools to address these postsurgical deficits. They utilize the multimodal approach found in standard physical therapy to address each potential layer of a patient’s postsurgical pain and function.

Stability

Until approximately 10 years ago, practitioners ranging from personal trainers to physical therapists treated strength and stabilization training as a single entity by applying strength-training principles to stability training. Today, these same providers are able to optimize training for stabilization function in muscles. It is important to understand that stabilization in the PM&R setting refers to muscular activity or function, and not necessarily an anatomical distinction of specific muscles. For example, the rotator cuff muscles of the shoulder may work as the primary mover of the arm, the secondary mover or synergist of the arm, and as a stabilizer in arm elevation. The stabilizing function of the cuff muscles acts to keep the humeral head depressed during elevation, in order to avoid impingement of soft tissues.10

In rotator-cuff arthropathy, the cuff muscles and tendons become compromised, and this stabilizing function may be diminished or lost, potentially leading to the need for reverse shoulder arthroplasty. There may be cases when the cuff muscles are strong when tested in isolation but fail to function as a group or fail to perform their stabilizing function. This situation may leave the shoulder joint vulnerable to more injury and trauma. Both strength and stability are requirements in healthy joint and muscle mechanics.11

The difference between stabilization training 20 years ago and today is the improved understanding of neuromuscular activation. Unlike strength, where losses tend to be progressive, stabilization loss may occur very rapidly and especially in the presence of pain. Motor control research has led to an understanding that pain, as well as gradual deconditioning, may simply turn off the stabilization switch, leaving it off until something turns it back on again.12 For this reason, patients with lower back pain typically present with poor stabilization function, often referred to as core weakness. Although core activation cannot be measured directly, indirect assessment using electromyography has been attempted.13

Stabilization training of the muscles and joints, therefore, should be conducted in an environment of “instability” to facilitate the stabilization response. Instability appears to be a natural stimulus for the deep lumbo-pelvic core muscles, such as transverse abdominus, to turn on. Suspension training grew out of this concept and has been used across the US since 2008 (see Figure 3).The Redcord system, manufactured in Norway, for example, allows large versatility in treatment of patients who require combined physical training and manual therapy. The patient and/or body part are suspended in a completely unstable environment, freeing the provider’s hands to position and mobilize other areas.

Another device challenges the body’s stabilization system. The seat on the SmartCore machine (Preventive Medical Health Care Co, Taiwan) is designed to swivel and tilt simultaneously, forcing the patient to try and keep the seat balanced using pelvic muscles with minimal assist from the arms (see Figure 4). The concept is consistent with that of creating a training environment that is inherently unstable in order to activate the deep core stabilizing muscles. Diagnostic ultrasound (see Figure 5) verifies the activation pattern of the deep pelvic stabilizers when using this device.

 

Scarring

Postsurgical scarring can be painful and unsightly to some people, and may lead to additional plastic surgery later on. In many cases, postsurgical scarring is also accompanied by inflammation in and around the scar. In response to an incision, the body begins the repair process by laying down layers of collagen, which may lead to a dysfunctional area in terms of vascularity and sensation. The cells within a scar are compressed and compacted, providing some mechanical strength at the expense of function and, in some cases, lymphatic circulation. When the cells are not compressed over the top of each other, they are able to function optimally.

The Physiotouch device (Physiotouch Inc, Palo Alto, CA), originally developed in Finland and also marketed as Lymphatouch, re-expands cells to their proper dimensions by combining negative pressure with vibration. The unit has found a place in many plastic surgery clinics and burn units across the country for its powerful ability to soften painful scars and assist in promoting lymphatic drainage, ultimately controlling pain by minimizing the discomfort of lymphatic congestion. In the PM&R space, providers have found that soft tissue, at times, needs to be decompressed in a manner similar to elements in the spine and skeleton to achieve benefit; the device offers a solution in this regard (see Figure 6).

Recent work at the Harvard bio-engineering labs have confirmed the value of mechanical forces on cells, known as mechano-transduction.14 These findings, paired with work in microphotography by surgeon Jean-Paul Guimberteau15 in France has elucidated the physical structure of the extracellular matrix, thereby providing a framework for better understanding the relationship between cell structure and function. 

The microphotography perspective has PM&R practitioners a unique and rare look at the microstructure of cells and their environment. In particular, this medical photography has served to elucidate the relationship between structure and function by providing an in-depth look at cell architecture. Even to the untrained viewer, the images convey a sense of interconnectedness from cell to cell through a vast array of microtubules and various other microgeometric shaped structures arranged in a complicated and chaotic pattern. We can begin to imagine how cells communicate and transport nutrients in and waste products out of this microscopic cellular universe. This work has served to also demonstrate and validate the role of physical forces on cells and how mechanical forces are essential for all living cells to function properly. The microphotography work further provides a visual dimension to the lab research performed by the Harvard bioengineering laboratories on mechano-transduction. The images allow us to see how mechano-biology may work in real life scenarios and how important the fascial system is to the human body.

Pain and Swelling

In many postsurgical patients, pain and swelling co-exist. Typically, swelling may be the primary cause of pain and the reason that anti-inflammatory medication may be more effective in relieving musculoskeletal pain than pain-masking analgesics. When pain and swelling are present, however, other movement parameters such as strength, mobility, and stability, may be stalled. Controlling or abolishing this arthogenic muscle inhibition is often, therefore, a clinical priority for physical medicine and rehabilitation providers.

Re-establishing proper perfusion and lymphatic flow are paramount. Various technologies may be used, with pulsed electromagnetic field therapy (PEMF) the preferred standard of care among PM&R providers. Unlike many popular treatments for pain and swelling, PEMF has an impressive and ever-growing research base at both the life science and translational studies level. PEMF treatment using the Provant device is one option (see Figure 7).

The author’s clinic (Biogenesis Group, Ypsilanti, Michigan) has conducted investigative efforts in the area of comparative effectiveness research, demonstrating PEMF efficacy at relieving pain and inflammation across the spectrum of acute and chronic musculoskeletal conditions (see, for example, a review of the new OSKA Pulse PEMF technology on page 53). Additional data collection for Provant is in process, with a previously calculated odds ratio of 3.3. The technology is quickly becoming the first-line treatment for pain management in outpatient centers across the country for its exceptional pain control, as well as enhanced oxygenation.

Conclusion

As surgical procedures and methods advance and consumer preference evolves, so too must the rehabilitation techniques used at to foster the recovery cycle in postoperative cases. This review provided a sampling of innovative surgical procedures in the realm of musculoskeletal medicine, and the subsequent changes in pain remediation treatment approaches—including used devices and equipment—facing physical medicine and rehabilitation specialists. It is expected that this trend will continue indefinitely.

 Dr. Marovino reports that he previously collaborated in a clinical pain trial that ended in 2016 with Regenesis and remains a key opinion leader for the company.

Last updated on: April 10, 2018
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Managing Perioperative Pain
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