Knee Pain

What is Knee Pain ?

The human knee is the largest joint in the body. It bears a huge weight load as it facilitates movement and support which leaves it vulnerable to injury. Knee pain can stem from any part of – or combination of – the complex joint structure which is made up of bones, ligaments, tendons and cartilage. It is a common issue and is symptomatic of a range of structural problems and underlying medical conditions – it is not simply a condition in itself, but rather a generalized term relating to a number of ailments with differing timeframes and prognosis for recovery.

When knee pain strikes it can restrict and hinder all aspects of your life – family, social, work, and recreation. Without successful treatment, persistent pain can have detrimental effects on the state of mind and mental wellbeing.

Types of Knee Pain

Generally speaking, knee pain is characterized by discomfort in the knee often accompanied by stiffness.

Other characteristics can include:

  • Bruising
  • Clicking
  • Locking
  • Unable to fully straighten
  • Unable to apply weight or ‘giving way’

Case Studies supporting PEMF benefits for Knee Pain

Effect of pulsed electromagnetic field therapy in patients undergoing total knee arthroplasty: a randomized controlled trial


Purpose: It has been reported that even one year after total knee arthroplasty (TKA), a relevant percentage of patients does not attain complete recovery and indicate unfavourable long-term pain outcome. We compared the clinical outcome of 33 patients undergoing TKA randomly assigned to the control or the pulsed electromagnetic field group (I-ONE therapy).

Methods : I-ONE therapy was administered postoperatively four hours per day for 60 days. Patients were assessed before surgery and then at one, two and six months postoperatively using international scores.

Results: One month after TKA, pain, knee swelling and functional score were significantly better in the treated compared with the control group. Pain was still significantly lower in the treated group at the six month follow-up. Three years after surgery, severe pain and occasional walking limitations were reported in a significantly lower number of patients in the treated group.

Conclusions: Advantages deriving from early control of joint inflammation may explain the maintenance of results at follow-up. I-ONE therapy should be considered an effective completion of the TKA procedure.

Effects of pulsed electromagnetic field on knee osteoarthritis: a systematic review


Objective: Many reviews have been previously published on the efficacy of pulsed electromagnetic field (PEMF) in the management of knee OA. However, their results regarding pain and function yielded conflicting conclusions. Therefore this study was conducted to determine the efficacy of PEMF as compared with a placebo.

Results: Fourteen trials were analysed, comprising 482 patients in the treatment group and 448 patients in the placebo group. When the efficacy of PEMF in treating pain was investigated, no significant effects were observed at any of the time points considered. However, when trials employing high-quality methodology were analysed, PEMF was significantly more effective at 4 and 8 weeks than the placebo. When the efficacy of PEMF was evaluated for function, a significant improvement was observed 8 weeks after the treatment initiation, with a standardized mean difference of 0.30 (95% CI 0.07, 0.53). No significant association was found between the use of PEMF and the occurrence of adverse events, as indicated by a relative risk of 1.47 (95% CI 0.67, 3.20). However, three (21.4%) trials applied electromagnetic field intensity over the levels recommended by the International Commission on Non-Ionizing Radiation Protection.

Conclusion: The present study provided suggestive evidence supporting PEMF efficacy in the management of knee OA. Our results further raise the need for more well-controlled trials, employing adequate methodology, to conclusively evaluate the efficacy of PEMF.

Effects of pulsed electromagnetic fields on patients’ recovery after arthroscopic surgery: prospective, randomized and double-blind study


Severe joint inflammation following trauma, arthroscopic surgery or infection can damage articular cartilage, thus every effort should be made to protect cartilage from the catabolic effects of pro-inflammatory cytokines and stimulate cartilage anabolic activities. Previous pre-clinical studies have shown that pulsed electromagnetic fields (PEMFs) can protect articular cartilage from the catabolic effects of pro-inflammatory cytokines, and prevent its degeneration, finally resulting in chondroprotection. These findings provide the rational to support the study of the effect of PEMFs in humans after arthroscopic surgery.

The purpose of this pilot, randomized, prospective and double-blind study was to evaluate the effects of PEMFs in patients undergoing arthroscopic treatment of knee cartilage. Patients with knee pain were recruited and treated by arthroscopy with chondroabrasion and/or perforations and/or radiofrequencies. They were randomized into two groups: a control group (magnetic field at 0.05 mT) and an active group (magnetic field of 1.5 mT). All patients were instructed to use PEMFs for 90 days, 6 h per day. The patients were evaluated by the Knee injury and Osteoarthritis Outcome Score (KOOS) test before arthroscopy, and after 45 and 90 days.

The use of nonsteroidal anti-inflammatory drugs (NSAIDs) to control pain was also recorded. Patients were interviewed for the long-term outcome 3 years after arthroscopic surgery. Thirty-one patients completed the treatment. KOOS values at 45 and 90 days were higher in the active group and the difference was significant at 90 days (P < 0.05). The percentage of patients who used NSAIDs was 26% in the active group and 75% in the control group (P = 0.015). At 3 years follow-up, the number of patients who completely recovered was higher in the active group compared to the control group (P < 0.05). Treatment with I-ONE aided patient recovery after arthroscopic surgery, reduced the use of NSAIDs, and also had a positive long-term effect.

Non-invasive electromagnetic field therapy produces rapid and substantial pain reduction in early knee osteoarthritis: a randomized double-blind pilot study


This study examined whether a non-thermal, non-invasive, pulsed electromagnetic field (PEMF), known to modulate the calmodulin (CaM)-dependent nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway, could reduce pain in early knee OA. This randomized, placebo-controlled, double-blind pilot clinical study enrolled 34 patients. Patient selection required initial VAS C4, 2 h of standing activity per day, and no recent interventions such as cortisone injections or surgery. Results showed VAS pain score decreased in the active cohort by 50 ± 11 % versus baseline starting at day 1 and persisting to day 42 (P\0.001). There was no significant decrease in VAS versus baseline at any time point in the sham cohort (P = 0.227). The overall decrease in mean VAS score for the active cohort was nearly threefold that of the sham cohort (P\0.001). The results suggest that nonthermal, non-invasive PEMF therapy can have a significant and rapid impact on pain from early knee OA and that larger clinical trials are warranted.

The effect of pulsed electromagnetic fields in the treatment of cervical osteoarthritis: a randomized, double-blind, sham-controlled trial


The purpose of this study was to evaluate the effect of electromagnetic field therapy (PEMF) on pain, range of motion (ROM) and functional status in patients with cervical osteoarthritis (COA). Thirty-four patients with COA were included in a randomized, double-blind study. PEMF was administrated to the whole body using a mat 1.8•0.6 m in size. During the treatment, the patients lay on the mat for 30 min per session, twice a day for 3 weeks. Pain levels in the PEMF group decreased significantly after therapy (p<0.001), but no change was observed in the placebo group. The active ROM, paravertebral muscle spasm and neck pain and disability scale (NPDS) scores improved significantly after PEMF therapy (p<0.001) but no change was observed in the sham group. The results of this study are promising, in that PEMF treatment may offer a potential therapeutic adjunct to current COA therapies in the future.

Pulsed electromagnetic field therapy and osteoarthritis of the knee: Synthesis of the literature

Knee joint osteoarthritis is a painful disorder, often resulting in progressive functional impairment and disability. One modality used in the treatment of knee osteoarthritis is pulsed electromagnetic field therapy. This article examines the evidence base that details the rationale for and the outcomes of applying pulsed electromagnetic fields to the osteoarthritic knee joint. The related English language literature was reviewed to examine whether pulsed electromagnetic fields applied to an osteoarthritic knee joint are likely to be efficacious, and if so why. Although limitations to the published literature on this topic exist, the available basic and seven randomized clinical research studies in this field support the value of continuing to explore the potential of applying pulsed electromagnetic fields to ameliorate pain and dysfunction associated with the osteoarthritic knee joint.

Further clinical research to validate the use of pulsed electromagnetic fields in lessening osteoarthritic knee joint pain and facilitating function and joint repair is indicated.

Osteoarthritis pathology

The focal point of osteoarthritic joint pathology is said to occur in the thin layer of tissue that covers the surfaces of freely moving joints, known as articular cartilage. This tissue is important to the health of the adult joint, because it serves to protect the joint from excessive impact during day-to-day activities and determines the effectiveness of the joint's cushioning responses to dynamic loading activities. Its viability is hence critical to the health of the joint (Mow et al, 1989; Mow and Wang, 1999).

However, in the osteoarthritic joint, there is an associated malfunction or destruction of that part of the articular cartilage occupied by cells known as chondrocytes, which alters the proteoglycan and collagen fibril constituents of cartilage and reduces its shock-absorbing property. In addition, if excessive impact is repeatedly transferred to the underlying bone, the underlying bone may sustain microfractures and lose its resiliency.

These changes commonly occur in tandem, but regardless of whether they occur alone or in combination, they are likely to have a detrimental effect on the joint's dynamic loading response, thus fostering progressive joint destruction processes (Pfeiffer, 2001).

As a result, joint loading pressures may be transmitted to the underlying bone where pain receptors reside (Wong et al, 1987; Mow et al, 1989). The presence of pain and disease-associated adaptive changes, particularly those in the surrounding soft tissues and muscles, can reduce functional capacity.

Pulsed electromagnetic fields and articular cartilage physiology

In the context of osteoarthritis, and many decades of research where it was believed that the articular cartilage defects accompanying this condition were irreversible, it is noteworthy that numerous studies have consistently shown that articular cartilage exposed to an electrical field can increase or retain its proteoglycan content (Smith and Nagel, 1983; Aaron and Ciombor, 1993, 1996; Ciombor et al, 2002; De Mattei et al, 2003). Moreover, the cartilage proteoglycan molecules synthesized appear to be normal in size and composition. Importantly, this effect is also found to be maintained in the presence of interleukin-lbeta, which commonly produces a net loss of tissue proteoglycan in osteoarthritic cartilage (De Mattei et al, 2003).

It is increasingly evident, therefore, that pulsed electromagnetic field applications can induce microcellular biological responses that may be helpful in preserving extracellular articular cartilage matrix integrity in late-stage osteoarthritis, where excessive proteoglycan losses and the catabolic activity of interleukin-lbeta are common. It may also confer a chondroprotective effect in early osteoarthritis, where excessive proteoglycan is laid down (Liu et al, 1997; Ciombor et al, 2001), but its size and composition may not be the same as that normally found under healthy conditions. In addition, pulsed electromagnetic field applications may stimulate chondrocyte proliferation (Pezzetti et al, 1999) and important DNA synthetic mechanisms in both prevailing and newly formed chondrocytes (Rodan et al, 1978; Pezzetti et al, 1999).

Important related work by Baker et al (1974) using an animal model has shown that cartilage defects exposed to an electrical current have a greater tendency to heal with hyaline cartilage than control defects, which heal mostly by fibrocartilage. A later study in which the circuitry was modified and inserted into full-thickness defects demonstrated chondrocytes and matrix compatible with normal articular cartilage. The authors conceded that electrical potentials induced by external magnetic fields may be 30 times lower when compared with endogenous potentials (Schmidt- Rohling and Ihme Silny, 2002), and findings from in vivo experiments may not reflect those that occur under normal circumstances. However, the study by Baker et al suggested that it may be worthwhile to further explore if the external application of pulsed electromagnetic fields to the osteoarthritic knee joint can produce similar results to those demonstrated by this group from direct exposure.

This is particularly appropriate as mature articular cartilage cells do not readily mount a repair response that results in adequate matrix reconstitution (Aaron and Ciombor, 1993; Trock, 2000). Pulsed electromagnetic field therapy, and an extension of this termed pulsed signal therapy, may be helpful in stimulating this process (Fioravanti et al, 2002). This is supported in a recent experiment in a guinea pig that had a form of arthritis similar to osteoarthritis (Ciombor et al, 2001).

Effects of pulsed electromagnetic fields on other joint tissues

Bone damage, another hallmark of osteoarthritic joint disease, may likewise be favourably affected by the application of pulsed electromagnetic field therapy. For example, osteonecrosis of the femoral head, which generally progresses to hip joint osteoarthritis within 2 or 3 years (Aaron et al, 1989), can be markedly attenuated by applying pulsed electromagnetic fields to the affected hip joints. This effect was also noted by Bassett et al (1989) over an average period of 4 years.

In addition to its direct effect on cartilage reconstitution (Norton, 1985; Trock, 2000), this ability of pulsed electromagnetic fields to stimulate bone healing (Borsalino et al, 1988; Mammi et al, 1993; Marks, 2000) may help to reduce cartilage destruction and preserve its integrity indirectly, and to delay the need for revision surgery (Kennedy et al, 1993).

Electromagnetic stimulation may also reduce osteoarthritic pain directly (Giordano et al, 2001) and ameliorate painful conditions often associated with osteoarthritis, such as tendinitis and soft tissue injury (Warnke, 1983; Binder et al, 1984; Foley-Nolan et al, 1992; Weinberger et al, 1996; Vallbona et al, 1997; Hershler and Sjaus, 1999) and muscle pain (Alfano et al, 2001). Additional documented benefits of pulsed electromagnetic fields in the context of osteoarthritis include enhanced collagen production (Farndale and Murray, 1985), ligamentous tissue healing (Wilson, 1972; Lin et al, 1992) and nerve regeneration (Wilson et al, 1974).

Why pulsed electromagnetic fields are effective in the context of joint physiology

Although there is a significant placebo effect associated with pulsed electromagnetic field applications (Hong et al, 1982), it is believed that electromagnetic fields can stimulate chondrocyte cell receptors and related transcription and synthetic processes (Aaron and Ciombor, 1993; Ciombor et al, 2003).

Another view is that by interacting with molecules on the chondrocyte cell surface membrane, pulsed fields can modify internal calcium concentrations and other ions that stimulate DNA transcription and trigger proteoglycan production (Rodan et al, 1978; Granziana et al, 1990; Lee et al, 1993). By upregulating members of the transforming growth factor B supergene family that have important regulatory functions in joints (Ciombor et al, 2003), electromagnetic fields may increase chondrocyte synthesis of proteoglycans directly (Aaron and Ciombor, 1993).

Other possible explanatory mechanisms are altered rates of transcription of c-myc and other genes, a reduction in spontaneous cell death, increased messenger RNA levels and changes in receptor activity that stimulate second messenger systems and positive plasma membrane changes (Nicolakis et al, 2002).

Pulsed electromagnetic field therapy for management of osteoarthritis-related pain, stiffness and physical function: clinical experience in the elderly


Background: Pulsed electromagnetic field (PEMF) therapy has shown promising therapeutic effectiveness on bone- and cartilage-related pathologies, being also safe for management of knee osteoarthritis.

Aim: The aim of this study was to investigate the clinical efficacy of a PEMF device for management of knee osteoarthritis in elderly patients.

Materials and methods: A total of 33 patients were screened, and 28 patients, aged between 60 and 83 and affected by bilateral knee osteoarthritis, were enrolled in this study. They received PEMF therapy on the right leg for a total of three 30-minute sessions per week for a period of 6 weeks, while the left leg did not receive any treatment and served as control. An intravenous drip containing ketoprofen, sodium clodronate, glucosamine sulfate, calcitonin, and ascorbic acid, for a total volume of 500 mL, was administered during PEMF therapy. At baseline and 3 months post-PEMF therapy, Visual Analog Scale (VAS) was used to assess knee pain and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) was used to measure knee pain, stiffness and physical function.

Results: Changes in VAS and WOMAC scores were calculated for both knees as baseline minus post-treatment. A two sample Student’s t-test, comparing change in knee-related VAS pain for PEMF-treated leg (49.8 ± 2.03) vs control leg (11 ± 1.1), showed a significant difference in favor of PEMF therapy (P , 0.001). A two sample Student’s t-test comparing change in knee-related WOMAC pain, stiffness, and physical function for PEMF-treated leg (8.5 ± 0.4, 3.5 ± 0.2, 38.5 ± 2.08, respectively) vs control leg (2.6 ± 0.2; 1.6 ± 0.1; 4.5 ± 0.5 respectively), also showed a significant difference in favor of PEMF therapy (P , 0.001). No adverse reactions to therapy were observed.

Conclusion: The present study shows that PEMF therapy improves pain, stiffness and physical function in elderly patients affected by knee osteoarthritis.

Peri-operative interventions producing better functional outcomes and enhanced recovery following total hip and knee arthroplasty: an evidence-based review


The increasing numbers of patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA), combined with the rapidly growing repertoire of surgical techniques and interventions available have put considerable pressure on surgeons and other healthcare professionals to produce excellent results with early functional recovery and short hospital stays. The current economic climate and the restricted healthcare budgets further necessitate brief hospitalization while minimizing costs. Clinical pathways and protocols introduced to achieve these goals include a variety of peri-operative interventions to fulfill patient expectations and achieve the desired outcomes. In this review, we present an evidence-based summary of common interventions available to achieve enhanced recovery, reduce hospital stay, and improve functional outcomes following THA and TKA. It covers pre-operative patient education and nutrition, pre-emptive analgesia, neuromuscular electrical stimulation, pulsed electromagnetic fields, peri-operative rehabilitation, modern wound dressings, standard surgical techniques, minimally invasive surgery, and fast-track arthroplasty units.

I-ONE Therapy in Patients Undergoing Total Knee Arthroplasty


Background: Total knee arthroplasty (TKA) is often associated with a severe local inflammatory reaction which, unless controlled, leads to persistent pain up to one year after surgery. Standard and accelerated rehabilitation protocols are currently being implemented after TKA, but no consensus exists regarding the longterm effects. Biophysical stimulation with pulsed electromagnetic fields (PEMFs) has been demonstrated to exert an antiinflammatory effect, to promote early functional recovery and to maintain a positive longterm effect in patients undergoing joint arthroscopy. The aim of this study was to evaluate whether PEMFs can be used to limit the pain and enhance patient recovery after TKA.

Methods: A prospective, randomized, controlled study in 30 patients undergoing TKA was conducted. Patients were randomized into experimental PEMFs or a control group. Patients in the experimental group were instructed to use IONE stimulator 4 hours/day for 60 days. Postoperatively, all patients received the same rehabilitation program. Treatment outcome was assessed using the Knee Society Score, SF36 HealthSurvey and VAS. Patients were evaluated preoperatively and one, two, six and 12 months after TKA. Joint swelling and Non Steroidal Anti Inflammatory Drug (NSAID) consumption were recorded. Comparisons between the two groups were carried out using a two-tail heteroschedastic Student's test. Analysis of variance for each individual subject during the study was performed using ANOVA for multiple comparisons, applied on each group, and a Dunnet post hoc test. A p value < 0.05 was considered statistically significant.

Results: Preoperatively, no differences were observed between groups in terms of age, sex, weight, height, KneeScore, VAS, SF36 and joint swelling, with the exception of the Functional Score. The KneeScore, SF36 and VAS demonstrated significantly positive outcomes in the IONE stimulated group compared with the controls at followups. In the IONE group, NSAID use was reduced and joint swelling resolution was more rapid than in controls. The effect of IONE therapy was maintained after use of the device was discontinued.

Conclusions: The results of the study show early functional recovery in the IONE group. IONE therapy should be considered after TKA to prevent the inflammatory reaction elicited by surgery, for pain relief and to speed functional recovery.

Case Study Reference Source:

  • 1. Chondroprotective Effects of Pulsed Electromagnetic Fields on Human Cartilage Explants
    (Authors: Alessia Ongaro, Agnese Pellati, Federica Francesca Masieri, Angelo Caruso, Stefania Setti, Ruggero Cadossi, Roberto Biscione, LeoMassari, Milena Fini, and Monica De Mattei)

  • 2. Effect of pulsed electromagnetic field therapy in patients undergoing total knee arthroplasty: a randomised controlled trial
    (Authors: Paolo Adravanti, Stefano Nicoletti, Stefania Setti, Aldo Ampollini, Laura de Girolamo)

  • 3. Effects of pulsed electromagnetic field on knee osteoarthritis: a systematic review
    (Authors: Seo Ryang We, Yun Hyung Koog, Kwang-Il Jeong and Hyungsun Wi)

  • 4. Effects of pulsed electromagnetic fields on patients’ recovery after arthroscopic surgery: prospective, randomized and double-blind study
    (Authors: C. Zorzi, C. Dall’Oca, R. Cadossi, S. Setti)

  • 5. Non-invasive electromagnetic field therapy produces rapid and substantial pain reduction in early knee osteoarthritis: a randomized double-blind pilot study
    (Authors: Fred R. Nelson, Raimond Zvirbulis, Arthur A. Pilla)

  • 6. The effect of pulsed electromagnetic fields in the treatment of cervical osteoarthritis: a randomized, double-blind, sham-controlled trial
    (Authors: Serap Tomruk Sutbeyaz, Nebahat Sezer Belma, Fusun Koseoglu)

  • 7. Pulsed electromagnetic field therapy and osteoarthritis of the knee: Synthesis of the literature
    (Authors: R Marks, J van Nguyen)

  • 8. Pulsed electromagnetic field therapy for management of osteoarthritis-related pain, stiffness and physical function: clinical experience in the elderly
    (Authors: Tommaso Iannitti, Gregorio Fistetto, Anna Esposito, Valentina Rottigni, Beniamino Palmieri)

  • 9. Peri-operative interventions producing better functional outcomes and enhanced recovery following total hip and knee arthroplasty: an evidence-based review
    (Authors: Mazin S Ibrahim, Muhammad A Khan, Ikram Nizam and Fares S Haddad)

  • 10. I-ONE Therapy in Patients Undergoing Total Knee Arthroplasty
    (Authors: Biagio Moretti, Angela Notarnicola, Lorenzo Moretti, Stefania Setti, Francesca De Terlizzi, Vito Pesce, Vittorio Patella