Pulsating signal therapy

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The Pulsed Signal Therapy (PST) is a controversial method of therapy , according to the proponents for treating a variety of diseases and damage to the cartilage , other connective tissue and bone can be used. Critics doubt its effectiveness.

method

According to information from "PST GmbH" (formerly "Signal Medizin Vertriebs GmbH"), the now patented PST process was developed by the German-American doctor and biophysicist Richard Markoll.

In 2000, the American Academy of Pain Management (the largest clinical association of interdisciplinary pain therapists in the USA) presented the John Liebeskind Research Award 2000 for the development of Pulsating Signal Therapy (PST).

The PST treatment cycles extend over nine or twelve working days, depending on the region treated. A single treatment lasts an hour.

Biochemical and pathophysiological basics

Cartilage consists of two components, the cartilage cells ( chondrocytes ) and the intercellular substance , which is also called the extracellular matrix. This intercellular substance, which consists of proteoglycans , collagens and glycoproteins , is produced by the chondrocytes. The high water content (up to 70%) is characteristic. The proteoglycans are negatively charged through biochemical modifications ( sulfate and carboxy groups ) and therefore represent polyanions . Dissociable protons (more precisely: protons attached to water, H 3 O + , also called hydronium ions ) attach to these groups . The charge density of the negative charges of the intercellular substance is responsible for the composition of the ionic environment in this space.

The ion distribution changes under pressure: The hydronium ions dissociate from proteoglycan molecules into the surrounding matrix fluid. The combination of hydronium ion flow and movements of the matrix liquid creates physicochemical effects, which are also called flowing potentials .

These flowing potentials and mechanical stimuli regulate the biosynthesis of the matrix proteins in the chondrocytes. In healthy cartilage, mechanical stress on the joint leads to electrical signals that regulate cartilage growth and its regeneration. Consequently, mechanoreceptors are also involved in the signal transduction chain that regulates gene expression in the chondrocytes .

In the diseased joint, there is less mechanical stress, which has a negative effect on the flowing potentials, the biosynthetic performance of the chondrocytes as well as cartilage growth and regeneration: Here matrix metalloproteinases (see the corresponding section in the entry intercellular substance ) seem to intervene. If these proteases are artificially activated in the cartilage tissue, matrix proteins are broken down and the flowing potentials are reduced by up to 80%. The breakdown products ( peptides ) of the matrix proteases induce further breakdown processes in chondrocytes, which further damage the cartilage.

Functional principle of the PST

A causal treatment of degenerative joint diseases using purely pharmacological methods appears difficult for two reasons :

  • Electrochemical and physical stimuli and their absence play a fundamental role in the physiology of chondrocytes in both healthy and diseased cartilage tissue due to the mechanisms of mechanoreception .
  • Medicines can therefore only intervene in the physiological processes in the already damaged cartilage, for example to stop the degeneration-enhancing processes triggered by the matrix proteases.

The therapeutic basis of PST consists in imitating and stimulating the electrophysiological processes taking place in healthy cartilage tissue by means of external physical stimuli. In particular, the flowing potentials should be restored. For this purpose, the cartilage tissue is exposed to pulsating magnetic fields .

The pulsating magnetic fields entering the tissue are intended to restore the normal biosynthetic capabilities of the chondrocytes and, in particular, to increase the concentration of the proteoglycan. In fact, positive effects on physiology (DNA synthesis , increased transcription rate , increase in protein biosynthesis, including proteoglycan) were found in in vitro experiments on chondrocytes after PST treatment . A study presented at a conference found that PST treatment decreased collagen expression. Increased collagen concentrations are characteristic of arthritic chondrocytes.

Practical implementation

The body part to be treated is stored inside an air core coil . The air-core coil is traversed by a pulsating direct current (curve shape rectangle), which leads to the formation of a pulsating magnetic field (also pulse-modulated magnetic field or pulse-like electromagnetic field , English PEMF pulsed electromagnetic field ) that is homogeneous within the coil. The frequency used is a few Hertz to around 30 Hz. According to Gierke, the magnetic flux density should be around 12.5 Gs (Gauss) , which corresponds to 1.25 milliTesla , another source gives 0.5–1.5 mTesla . During the application the current strength and thus the flux density is changed. This corresponds to a maximum of 50 times the earth's magnetic field . However, the patient does not feel any of these fields during the one-hour treatment. According to the manufacturer's information, the PST process differs from other PEMF processes with uniform pulse patterns (constant working frequency and flux density) in that it works with rectangular pulses that change in duration and intensity (variable frequency and variable flux density) and so adapt better to natural physiological pulses should.

Indications and contraindications

As an indication for PST, proponents u. a. the onset of osteoarthritis up to stage III according to Kellgren. Success can also be achieved in individual cases with advanced osteoarthritis, but it is generally no longer recommended. An indispensable prerequisite for the success of the therapy is that there is still a small amount of cartilage that can be regenerated. In addition to osteoarthritis, PST is also increasingly being used to treat soft tissue injuries such as overload damage or insertion tendinopathies. All joints including the spine can be treated.

Absolute contraindications are tumors in the treatment area (treatment only possible after five years) or bacterial infections. Treatments of the lumbar spine and pelvis are mentioned as relative contraindications for pregnancy and treatments of the cervical spine, thoracic spine and shoulder for pacemaker .

effect

The effectiveness of the procedure presented in Germany in October 1996 is controversial.

It is undisputed that certain electromagnetic fields have a stimulating effect on cartilage growth at the cellular level. A systematic review of 102 articles up to 2001 could only identify three studies that met scientific criteria. They showed a low to moderate, statistically significant positive effect of the therapy. Therapy successes have also been documented in smaller studies with other types of application of electromagnetic fields, for example using 1.8 × 0.6 meter mats.

Proponents of PST point to positive experiences from the USA , where more than 10,000 patients had already been treated successfully in the 1990s, and positive experiences from the treatment of around 300,000 patients in Germany.

Critics do not see the effectiveness as proven. Jürgen Krämer, Director of the Orthopedic Clinic Bochum in 1997: As long as the effectiveness of the method has not been proven, the use of the PST is "extremely problematic".

In Germany, the "Federal Committee of Doctors and Health Insurance Funds", whose successor is today the Federal Joint Committee , carried out an extensive assessment of the PST in 1998 at the request of the National Association of Statutory Health Insurance Physicians . After analyzing and evaluating all the statements and the scientific literature, he came to the conclusion that the effectiveness and medical necessity of PST for the claimed indications had not been adequately proven. The only prospective double-blind and placebo-controlled study carried out at the time showed serious methodological deficiencies. The alleged safety of the procedure is not proven due to a lack of studies with an adequate follow-up period. The available documents were considered so unstable that partial recognition for some indications could not be justified. "Long-term observations on the benefits and risks of pulsating signal therapy were not available, although the method has been tested on patients for years." The method is also not eligible .

An overview by H. Gierse in 2003 describes the current status of the effectiveness of PST in osteoarthritis treatment as follows:

"Clinical studies ... were able to show the positive aspect of PST on osteoarthritis systems .... An improvement is found in 73% to 87% of those affected"

About the state of the experimental studies of the mechanism of action with reference to:

"The positive results found under PST treatments - such as increasing the number of cells, enlarging the chondrocytes - pellets, increasing the hydroxyproline content - could not be found in studies with other magnetic field therapies."
".. the data situation with the available evidence is currently not sufficient to clearly characterize and quantify the mechanism of action of PST. Further studies on the mechanism of action are required."

Side effects

Side effects are not yet known in around 300,000 people treated with PST.

According to Gierse

".. PST has an established value as an alternative therapy method for the treatment of osteoarthritis due to its freedom from side effects, the lack of infection risks and because it is gentle and painless and no intervention is necessary."

Economical meaning

As a therapy method not recognized by the statutory health insurances in Germany , the PST is offered to patients as a so-called IGeL service and billed. The price is 663 to 885 euros for nine to twelve one-hour applications. In 1997, “PST GmbH”, which specializes in the worldwide distribution of trademarked PST technology, pursued the strategy of leasing the devices from doctors . The procedure was offered to orthopaedists as a "second pillar" in the doctor's practice. In 2005, PST was ranked fourth among the most profitable IgeL services for doctors .

According to the sales company, while the process is widespread in Germany, Austria, Switzerland and some other countries, there are hardly any users in England and the Netherlands, for example.

Individual evidence

  1. ↑ Awards. In: Deutsches Ärzteblatt. 98, Issue 6, February 9, 2001, Pages A-347, B-292, C-272. (last accessed May 25, 2010)
  2. ^ EH Frank, AJ Grodzinsky: Cartilage electromechanics-II. A continuum model of cartilage electrokinetics and correlation with experiments. In: J. Biomech. 20, 1987, pp. 629-639. PMID 3611138
  3. ^ EH Frank, AJ Grodzinsky: Cartilage electromechanics-I. Electrokinetic transduction and the effects of electrolyte pH and ionic strength. In: J. Biomech. 20, 1987, pp. 615-627. PMID 3611137
  4. ↑ a b Y. J. Kim, LJ Bonassar, AJ Grodzinsky: The role of cartilage streaming potential, fluid flow and pressure in the stimulation of chondrocyte biosynthesis during dynamic compression. In: J. Biomech. 28, 1995, pp. 1055-1066. PMID 7559675
  5. ↑ JB Fitzgerald, M. Jin, AJ Grodzinsky: Shear and compression differentially regulate clusters of functionally-related temporal transcription patterns in cartilage tissue. In: J. Biol. Chem. 281, 2006, pp. 24095-24103. PMID 16782710
  6. ↑ RK Aaron, DM Ciombor, S. Wang, B. Simon: Clinical biophysics: the promotion of skeletal repair by physical forces. In: Ann. NY Acad. Sci. 1068, 2006, pp. 513-531. PMID 16831948 .
  7. ↑ AJ Grodzinsky, ME Levenston, M. Jin, EH Frank: Cartilage tissue remodeling in response to mechanical forces. In: Annu. Rev. Biomed. Closely. 2, 2000, pp. 691-713. PMID 11701528
  8. ^ DR Carter, GS Beaupre, M. Wong, RL Smith, TP Andriacchi, DJ Schurman: The mechanobiology of articular cartilage development and degeneration. In: Clin. Orthop. Relat. Res. 427 Supplement, 2004, pp. 69-77. PMID 15480079
  9. ↑ LJ Bonassar, JL Stinn, CG Paguio, EH Frank, VL Moore, MW Lark, JD Sandy, AP Hollander, AR Poole, AJ Grodzinsky: Activation and inhibition of endogenous matrix metalloproteinases in articular cartilage: effects on composition and biophysical properties. In: Arch Biochem Biophys . 333, 1996, pp. 359-367. PMID 8809074
  10. ^ T. Yasuda: Cartilage destruction by matrix degradation products. In: Mod. Rheumatol. 16, 2006, pp. 197-205. PMID 16906368
  11. ↑ A. Fioravanti, F. Nerucci, G. Collodel, R. Markoll, R. Marcolongo: Biochemical and morphological study of human articular chondrocytes cultivated in the presence of pulsed signal therapy. In: Ann Rheum Dis . 61, 2002, pp. 1032-1033. PMID 12379533
  12. ↑ egms.de
  13. ↑ C. Grimmer, N. Balbus, U. Lang, T. Aigner, T. Cramer, L. Muller, B. Swoboda, D. Pfander: Regulation of type II collagen synthesis during osteoarthritis by prolyl-4-hydroxylases: possible influence of low oxygen levels. In: Am. J. Pathol. 169, 2006, pp. 491-502. PMID 16877351
  14. ↑ German Spinal League ( Memento from September 26, 2003 in the Internet Archive ), accessed on January 1, 2014. Attention: The original has been de-published, the archive version may contain incorrect and outdated information!
  15. ↑ a b c d e H. Gierse: Current status of pulsating signal therapy for the treatment of osteoarthritis (PDF; 486 kB). In: German magazine for sports medicine. 54, 2003, pp. 212-214, accessed November 12, 2010.
  16. ↑ J. Hulme et al.: Electromagnetic fields for the treatment of osteoarthritis. In: Cochrane Database Syst Rev. 2002, p. CD003523. PMID 11869668
  17. ↑ ST Sutbeyaz include: The effect of pulsed electromagnetic fields in the treatment of cervical osteoarthritis: a randomized, double-blind, sham-controlled trial. In: Rheumatol Int. 26, 2006, pp. 320-324. PMID 15986086 .
  18. ↑ a b S. Glöser: Pulsating signal therapy: alternative method as "additional financial income". In: Deutsches Ärzteblatt . 94, 1997, pp. A-2236. (online) , accessed August 9, 2006.
  19. ↑ a b D. H. Trock, AJ Bollet, R. Markoll: The effect of pulsed electromagnetic fields in the treatment of osteoarthritis of the knee and cervical spine. Report of randomized, double blind, placebo controlled trials. In: J Rheumatol . 21, 1994, pp. 1903-1911. PMID 7837158
  20. ↑ Federal Committee of Doctors, Health Insurance Companies : Pulsating Signal Therapy (PST) . accessed online as PDF (2000) on November 12, 2010.
  21. ↑ Exclusion of scientifically not generally recognized treatment methods from the eligibility. (PDF) ( Memento of October 7, 2007 in the Internet Archive )
  22. ↑ B. Schmidt-Rohlfing, K. Gavenis, J. Silny, U. Schneider: Exposure of human chondrocytes in a 3D matrix with electromagnetic fields: histological and molecular biological investigations. In: Z. Orthop. (2002) 140S, 76 D126
  23. ↑ M. Faensen, R. Breul: Prospective multicenter study for the treatment of osteoarthritis of the knee (Kellgren II and III) with PST. In: Orthopedic Practice. 37, 2001, pp. 701-709.
  24. ↑ M. Faensen: Pulsating Signal Therapy, working principle and range of applications. In: Physiotherapy med. 2000.
  25. ↑ Praxisportal.de: The growing market with IGeL . praxisportal.de ( Memento of the original from October 9, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed August 9, 2006. @1@ 2Template: Webachiv / IABot / www.praxisportal.de