Knee pain takes on several forms and there are many ways to treat knee pain. The knee is one of the largest, most complex joints in the body. It is made up of four bones: The femur, the tibia, the fibula, and the patella. The muscles that support the knee are the quadriceps, in the front of the knee, and the hamstrings, in the back. These structures are connected through an intricate compilation of ligaments and cartilage.
The anterior cruciate ligament (ACL) prevents the femur from moving backwards onto the tibia, and the posterior cruciate ligament (PCL) prevents the femur from sliding forwards. There are two collateral ligaments, medial and lateral, that also help to provide support. The meniscus (lateral and medial) is tissue that sits between the femur and the tibia, providing ease of movement between the two bones. There is also articular cartilage that sits behind the patella. The knee is surrounded by bursae, fluid filled sacs which help to cusion the knee joint.
The main movement of the knee is bending (flexion) and straightening (extension). The knee is also capable of twisting, which is what accounts for many traumatic injuries to the ligaments of the knee. Some symptoms of this type of injury include a “popping” sound, immediate inability to bear weight on the affected limb, or a sensation that the knee is going to “give way.” These types of injuries typically warrant surgical referral. Twisting can also cause injury to the tendons (tendonitis) or the meniscus.
Both of these types of injuries can cause pain and swelling, as well as difficulty straightening the leg. Another main cause of knee pain is degeneration. Osteoarthritis of the knee is considered a “wear and tear” condition in which the cartilage in the knee degenerates as we age. When osteoarthritis becomes severe, there is no more (or very little) cartilaginous cushion between the knee bones, which can cause significant pain. Chondromalacia patella is also a type of degeneration, and generally means that there is damage to the cartilage beneath the kneecap.
The most important aspect of treating knee pain is establishing a diagnosis, usually by way of knee MRI. There are several injections that may help knee pain. One of the most common injections is a corticosteroid injection directly into the knee joint. This type of injection reduces inflammation and pain. Viscosupplementation (Orthovisc, Synvisc) provides lubrication to the knee joint for persons with degenerative conditions such as osteoarthritis. There are also several nerve blocks that may be beneficial.
The most common type of nerve block for knee pain is called a saphenous nerve block, which can provide relief to persons with many types of knee pain, including people who have undergone total knee replacement. Other very helpful treatment modalities for knee pain include chiropractic therapy, gait analysis, bracing, and TENS unit application. Physical therapy can help to strengthen the muscles surrounding the knee joint, improving its stability. Utilizing ice on the knee can help decrease pain and swelling.
Anti-inflammatory medications (ibuprofen, naproxen sodium, Celebrex) are the mainstay of treatment for people with knee pain, however other types of medication may be helpful as well. Neuropathic medications (gabapentin, Lyrica) are beneficial for persons that have neuropathic pain symptomatology (burning, numbness, ‘pins and needles’), and opioid medications (hydrocodone, oxycodone) are beneficial for people with acute knee injuries. If a person is experiencing an acute-type injury of the knee, an orthopedic surgery referral is typically warranted. If the patient does not respond to more conservative treatments, neuromodulation through spinal cord stimulation may be considered. Spinal cord stimulation involves small electrodes placed within the epidural space of the spine. The theory behind spinal cord stimulation is that stimulation of the large nerve fibers will inhibit the small nerve fibers, thus blocking the sensation of pain. Peripheral nerve stimulation (PNS) is very similar to spinal cord stimulation, but the electrodes are placed along the peripheral nerves, typically close to the area of pain.
Under a local anesthetic and minimal sedation your doctor will first place the trial leads into the peripheral space. The trial stimulator is typically worn for 5-7 days and connected to a stimulating device. If the trial successfully relieves your pain you can decide to undergo a permanent SCS/PNS if desired. Knee pain can be quite disabling, as we use our knees every day for virtually every activity we participate in. At Florida Spine Institute, we know we can help. We provide a comprehensive and multidisciplinary approach to your pain. If you suffer from chronic knee pain, please call us to schedule an appointment today!
Pain Pract. 2015 Apr 10. doi: 10.1111/papr.12292. [Epub ahead of print]
Total knee replacement (TKR) is a terminal therapy for osteoarthritis (OA) of the knee. While TKR results are generally satisfactory, a significant proportion of patients experience persistent pain lasting > 3 months following surgery, even after a technically acceptable operation. Knee pain of any kind post-TKR has been reported in up to 53% of patients, while 15% of patients have reported severe pain. Pain post-TKR is worse than preoperative pain in 7%, often resulting in surgical revision. The clinical experience of a patient that originally presented to an orthopedic surgeon with OA of both knees demonstrates an alternative relatively noninvasive pain management strategy: cooled radiofrequency (CRF) ablation of sensory nerves.
PM R. 2014 Apr;6(4):373-6. doi: 10.1016/j.pmrj.2013.10.003. Epub 2013 Dec 27.
Recently, investigators began using radiofrequency to manage knee osteoarthritis pain in patients at high risk who cannot undergo surgical intervention. To our knowledge, no study has investigated the use ofradiofrequency ablation of the genicular nerves to alleviate chronic knee pain after total knee replacement. A single case is presented here in which genicular nerve ablation successfully improved pain and restored function. We believe that these preliminary results could be used in the development of future prospective cohort studies and randomized controlled trials that focus on the use of radiofrequency ablation to treat persistent knee pain after total knee replacement.
J Chin Med Assoc. 2011 Aug;74(8):336-40. doi: 10.1016/j.jcma.2011.06.004. Epub 2011 Jul 23.
Osteoarthritis (OA) is the most widespread chronic joint disease worldwide. Symptomaticknee OA is observed in approximately 12% of individuals more than 60 years of age. Conservative treatments models may not be effective always, and that some of them have serious adverse effects that prompted the researchers to research different treatment methods. In this study, we investigated short- and mid-term effectiveness of intra-articular pulsed radiofrequency (PRF) applied in patients with chronic knee pain due to OA.
This study was carried out in the pain management center of a university hospital between January 2009 and June 2009. The patient record files of 31 patients who received intra-articular PRF were retrospectively reviewed. The antero-lateral area of the knee, where the intervention would be applied, was anesthetized with 1% lidocaine. An introducer needle was placed intra-articularly. PRF was started as 42°C at 2 Hz for 15 minutes. The pain of the patients was evaluated by 10 cm Visual Analog Scale (VAS). Furthermore, the ages, the gender, the symptom duration of the patients, the side of the knee on which the intervention was applied, and the complications were collected for statistical evaluation.
Although the mean initial VAS scores of the patients were 6.1 ± 0.9 cm, it was found, respectively, to be 3.9 ± 1.9 cm and 4.1 ± 1.9 cm at the first- and sixth-month follow-ups. In general, a decrease of 32.8% in mean in the VAS scores was achieved in the last follow-up; whereas the rate of patients reporting a minimum decrease of 2 points in the VAS scores was 64.5% and the rate of patients reporting a decrease of ≥50% in their pain was calculated as 35.5%.
PRF applied to the knee joint appears to be an effective and safe method.
J Back Musculoskelet Rehabil. 2011;24(2):77-82. doi: 10.3233/BMR20110277.
BACKGROUND AND OBJECTIVE:
We studied the long-term efficacy of pulsed radiofrequency treatment (PRF) on the saphenous nerve in 115 patients with chronic knee pain.
MATERIALS AND METHODS:
115 patients with chronic knee pain were investigated in a period of 22~months retrospectively. All patients had pulsed radiofrequency to the saphenous nerve. The mean age was 59 (range, 51-67). All patients were accessed with the visual analog scale (VAS) and WOMAC score pain at rest, pain on movement, and pain in flexion at 10th day, 3rd and 6th~months post procedure.
All patients showed improvement in their VAS scores as well as in their WOMAC scores after ten day, three month, and 6 months (p=0.001). No side effects were reported.
PRF application to the saphenous nerve for eight minutes showed remarkable amount of patient satisfaction. Application of PRF for the second time could be recommended if it shows some benefit after the sixth month. But none of our patients needed a second application of PRF after six months period.
Chronic osteoarthritis (OA) pain of the knee is often not effectively managed with current non-pharmacological or pharmacological treatments. Radiofrequency (RF) neurotomy is a therapeutic alternative for chronic pain. We investigated whether RF neurotomy applied to articular nerve branches (genicular nerves) was effective in relieving chronic OA knee joint pain. The study involved 38 elderly patients with (a) severe knee OA pain lasting more than 3 months, (b) positive response to a diagnostic genicular nerve block and (c) no response to conservative treatments. Patients were randomly assigned to receive percutaneous RF genicular neurotomy under fluoroscopic guidance (RF group; n=19) or the same procedure without effective neurotomy (control group; n=19). Visual analogue scale (VAS), Oxford knee scores, and global perceived effect on a 7-point scale were measured at baseline and at 1, 4, and 12weeks post-procedure. VAS scores showed that the RF group had less knee joint pain at 4 (p<0.001) and 12 (p<0.001) weeks compared with the control group. Oxford kneescores showed similar findings (p<0.001). In the RF group, 10/17 (59%), 11/17 (65%) and 10/17 (59%) achieved at least 50% knee pain relief at 1, 4, and 12 weeks, respectively. No patient reported a post-procedure adverse event during the follow-up period. RF neurotomy of genicular nerves leads to significant pain reduction and functional improvement in a subset of elderly chronic knee OA pain, and thus may be an effective treatment in such cases. Further trials with larger sample size and longer follow-up are warranted.
Knee Surg Sports Traumatol Arthrosc. 2008 Jun;16(6):565-73. doi: 10.1007/s00167-008-0506-1. Epub 2008 Mar 8.
Both mechanical shavers and radiofrequency-based devices are used to treat symptomatic partial thickness chondral lesions. Controversy exists as to which mode of treatment provides better outcomes. The purpose of this study was to compare clinical results after bipolar radiofrequency-based chondroplasty (RFC) to mechanical shaver debridement (MSD). Patients (n = 60) included in the study presented with knee pain associated with a medial meniscus tear and idiopathic ICRS grade III defect of the medial femoral condyle. Patients who had osteoarthritis, grade II or higher cartilage defects of the tibial joint surface, the lateral compartment, or the femoro-patellar joint, or had previously undergone surgery on the affected knee were excluded. Patients underwent partial meniscectomy; during the procedure, they were randomly assigned to receive bipolar RFC (Paragon, ArthroCare Corporation, Austin, TX) or MSD (Full radius resector LR 4.85 x 12.5 cm), Arthrex, Naples, FL). Postoperatively, the same physiotherapist provided instructions for a daily 2-h home training program consisting of isometric, isotonic, and leg lifting exercises; patients were provided the option of using crutches. Clinical outcomes were assessed using the Tegner score, visual analogue scale (VAS) score, and Knee and Osteoarthritis Outcome Score (KOOS) assessment, which consists of five principal domains including pain, symptoms, function in daily living (ADL), and knee related quality of life (QOL), where a score of 0 indicates extreme symptoms and 100 represents no symptoms. Age and time from injury onset did not differ significantly between the RFC and MSD groups (43 +/- 10 vs. 44 +/- 9 years, P = 0.732; 8 +/- 3 vs. 7 +/- 4 months, P = 0.279). No complications or adverse events were observed. Preoperatively, mean (+/-SD) scores for all KOOS principal domains were <20 and did not differ significantly (P > 0.05) between treatment groups. Postoperatively, the RFC patients returned to activity significantly earlier than MSD patients (17 +/- 7 vs. 22 +/- 6 days, P = 0.002). VAS pain scores at 6 h, 24 h, 6 weeks, and 1 year were significantly (P < 0.001) lower for the RFC group than for the MSD group (4 +/- 2, 2 +/- 0.5, 2 +/- 1, 2 +/- 1 vs. 8 +/- 1, 4 +/- 1, 4 +/- 1, 3 +/- 1, respectively). At 1 year, RFC patients had significantly better Tegner score (4.1 +/- 0.8 vs. 2.8 +/- 0.6, P < 0.001) and KOOS domain scores for pain, symptoms, ADL, QOL, respectively (81.1 +/- 8, vs. 59.4 +/- 12.8; 80.7 +/- 7.5 vs. 59.6 +/- 7.5; 81.5 +/- 6.5 vs. 60.1 +/- 6.9; 80 +/- 10 vs. 61.3 +/- 12.5; P < 0.001) than MSD patients. Significantly fewer RFC patients (2% vs 23%, p = 0.026) reported using NSAIDS for knee pain at 1 year. Patients undergoing radiofrequency-based chondroplasty for ICRS grade III medial femoral condyle chondral lesions in conjunction with partial meniscectomy had significantly better clinical outcomes through 1 year than patients with similar pathology receiving chondral debridement using the mechanical shaver.