Nonsurgical Interventions



Fig. 13.1
MRI arthrogram of the hip demonstrating a small superior labral tear









    13.2 Introduction


    The aim of this chapter is to provide an overview of some of the more common injection therapies for sports-related disorders of the hip and pelvis. Additionally, we provide technical instruction that will allow the interested clinician an opportunity to learn basic office-based procedures.

    The principal form of injection therapies involves the use of a combined corticosteroid and anesthetic injection into or around a symptomatic musculoskeletal structure . The use of cortisone was first reported in 1949 by a team of physicians at the Mayo Clinic [1] and resulted in a Nobel Prize in 1950. Since 1950, the injection of corticosteroid has been applied to a plethora of musculoskeletal conditions with varied efficacy.

    Although corticosteroid injections are an exceedingly common form of treatment applied today, their role in symptomatic management of sports injuries remains a topic of some controversy. Prospective, randomized, controlled studies support their use in disorders such as osteoarthritis of the hip and knee [2, 3]. However, one should not automatically conclude that these results can be generalized to all musculoskeletal conditions.

    In addition to corticosteroids and local anesthetics, proliferative therapy (prolotherapy) and viscosupplementation (injection of hyaluronic acid compounds) have been investigated as treatments for injured athletes. Preliminary studies have shown effectiveness for select musculoskeletal conditions and provide promise for further randomized, clinical controlled studies [47]. Lastly, regenerative medicine approaches with platelet rich plasma and mesenchymal stem cell injections are emerging therapies under study for their restorative and healing effects.


    13.3 Rationale for Use


    Given their relative safety, ease of use in trained hands, and cost-effectiveness, injection therapies can be a very useful modality when more conservative treatment measures have failed. Prior to performing any type of injection, the clinician must have a thorough understanding of the regional anatomy as well as procedural contraindications and precautions. The proceduralist must also have a thorough understanding of the various injection constituents and their potential side effects.


    13.4 Diagnostic Injections


    Injection therapies containing local anesthetics can be helpful in establishing a diagnosis when performed with precision. The rationale is that one can identify a symptomatic nociceptive structure by infiltrating it with a local anesthetic. Examples include intra-articular injections (hip and sacroiliac joint), soft tissue injections (bursa and peritendon infiltration), and peripheral nerve blocks (such as lateral femoral cutaneous nerve block).

    To reduce the incidence of false positive responses one must use a small enough volume of injectate, such that it will only anesthetize the targeted nociceptive structure. Otherwise, the anesthetic may diffuse to nearby tissues and cause pain relief by inadvertent effect on structures not targeted in the procedure.

    Image guidance can be used to significantly increase the accuracy of reaching the desired target tissue and thereby enhance diagnostic accuracy. Image guidance is highly recommended when performing diagnostic injections. Increasingly, ultrasound is being used in office-based sports medicine practices to help guide injection therapies [8, 9]. Ultrasound can be particularly helpful when trying to localize peripheral nerves and musculature for diagnostic block [10]. One advantage of ultrasound is that during the injection, additional relevant pathology such as hip joint effusion, bursitis, or tendinopathy may be visualized which may impact what structures are ultimately targeted during the procedure. One potential limitation, however, is the lack of sound wave penetration in large patients, which may limit visualization of deeper tissues. Additionally, it takes considerable training and experience with diagnostic ultrasound to use this method of image guidance effectively.

    Fluoroscopy is the standard method of image guidance used in pain clinics and interventional radiology suites. Accurate placement of the procedural needle can be directly visualized under fluoroscopic guidance. With the injection of a radiopaque contrast media, one can confirm the injection has reached the target tissue. Furthermore, the use of contrast can identify vascular uptake when injections are being performed near blood vessels such as during nerve blocks. This reduces false negative responses (through inadvertent vascular injection) and guards against systemic toxicity when performing large-volume field blocks.

    Diagnostic blocks can also be performed with great accuracy using computed tomography (CT) and MRI guidance [11]; however, this is rarely necessary if ultrasound or fluoroscopy is available to the experienced proceduralist.

    An additional diagnostic application of injection therapies is aspiration and analysis of joint effusions. Joint fluid analysis can differentiate among various pathophysiologies such as infection, gout, pseudo gout, inflammation, and hemorrhage.


    13.5 Therapeutic Injections


    The purpose of therapeutic injections is principally to improve pain and allow for restoration of function. The precise effect of each procedure depends on the structure injected and the pharmacologic / biologic agent utilized.


    13.6 Pharmacological Agents



    13.6.1 Corticosteroids


    Corticosteroid preparations are the most commonly utilized injectate because of their effects as potent inhibitors of inflammation. They modify the local inflammatory response through stabilization of lysosomal membranes, inhibition of cellular metabolism (e.g., neutrophil chemotaxis and function), inhibition of polymorphonuclear leukocyte membrane microtubular function, and establishment of decreased local synovial permeability. Corticosteroids can also increase the viscosity of synovial fluid, alter production of hyaluronic acid synthesis, and change synovial fluid leukocyte activity [12], all of which may improve symptoms secondary to degenerative, inflammatory, and overuse syndromes.

    Though many different preparations are available for joint and soft tissue injections, corticosteroids differ with respect to potency, solubility, and relative duration of action. The relative potency of individual corticosteroids is compared in Table 13.1 [13].


    Table 13.1
    Relative potency of corticosteroid preparations




































    Corticosteroid

    Relative anti-inflammatory potencies

    Equipotent doses (mg)

    Cortisone

    0.8

    25

    Hydrocortisone

    1.0

    20

    Prednisone

    4

    5

    Methylprednisolone acetate

    5

    4

    Dexamethasone sodium phosphate

    25

    0.6

    Betamethasone

    25

    0.6


    Adapted or reprinted with permission from Joint and Soft Tissue Injection, July 15, 2002, Vol 66, No 2, American Family Physician Copyright © 2002 American Academy of Family Physicians. All Rights Reserved

    Few studies have investigated the duration of action of corticosteroid agents in joints or soft tissues. In general, the duration of effect is inversely related to the solubility of the therapeutic agent. The less soluble agents remain in the joint or soft tissue longer and provide more prolonged effect. Nevertheless, shorter acting solutions are less irritating to the joint space and less likely to produce a post-injection pain flare. Agents with low solubility should be used primarily for intra-articular therapy and should be avoided in soft tissues due to the increased risk of soft tissue atrophy from prolonged local corticosteroid action.


    13.6.2 Hyaluronic Acid


    Intra-articular injection of hyaluronic acid is used to treat the pain associated with osteoarthritis of the knee with several randomized controlled studies showing reasonable efficacy [14]. The rationale for the use of hyalurons therapeutically is based on observations that hyaluronic acid is an important component of synovial fluid that acts as a cushion and lubricant for the joint. It serves as a major component of the extracellular matrix of the cartilage, helping to enhance the ability of cartilage to resist shear forces and maintain a resiliency to compression [15]. A systematic review published in 2006 suggests that injections with hyaluronic acid may also benefit people with osteoarthritis of the hip [4]. Intra-articular injection of hyaluronic acid into the hip joint appears to be safe and well tolerated [16], however only a small number of randomized clinical trials in humans have been published [1719].


    13.6.3 Anesthetics


    Local anesthetics can assist in identification of a symptomatic nociceptive structure by producing a rapid reduction in pain following injection/infiltration. Typically however, when performing intra-articular and soft tissue injections an anesthetic is mixed with a corticosteroid. Not only does this provide temporary analgesia and confirm delivery of the medication to the symptomatic structure, it dilutes the crystalline suspension of the corticosteroid and thus provides better diffusion of medication throughout the injected region. An allergic reaction to the amide local anesthetics such as lidocaine and bupivacaine is very rare.


    13.6.3.1 Lidocaine


    For most procedures 1 % lidocaine is used due to its rapid onset of action. However, because of its short half-life, lidocaine’s duration of therapeutic effect is short (1–2 h) [20]. At high concentrations lidocaine (5 %) is neurotoxic to local peripheral nerves and thus it can be used as a form of peripheral neurolysis [21]. Systemic toxicity would be rare in a standard sports medicine practice. The toxic effects of local anesthetics are highly dependent on the route of injection and the rapidity of absorption or uptake into the local vasculature [20]. Intra-articular and most soft tissues are not heavily vascularized, thus reducing the chance of central toxicity.


    13.6.3.2 Bupivacaine


    When longer acting local analgesia is desired, the use of an agent such as bupivacaine is preferable because of its duration of effect of 3–6 h [22]. However, bupivacaine has a longer time to the onset than lidocaine (2–10 min) and thus will not help attenuate the pain of the injection procedure itself. Bupivacaine is typically used in a strength of 0.25 % for musculoskeletal injections.


    13.6.4 Proliferants


    Prolotherapy is the injection of a substance that activates the inflammatory cascade and thus induces fibroblast proliferation . One objective of proliferative therapy is to strengthen incompetent ligaments that exhibit laxity [23]. For example, a gymnast who has low back pain from a hypermobile sacroiliac joint, a series of prolotherapy treatments over the dorsal sacral ligaments may strengthen them and thereby reduce motion and pain. A second application of prolotherapy is to stimulate the repair of tendons that have undergone chronic degeneration (tendinosis), once again by inciting an inflammatory response which then reactivates the healing process [23]. A number of substances can be used for prolotherapy such as compounds containing phenol, glucose, and glycerine . Another commonly used substance is dextrose (10–12 % concentration) which is potentially less neurotoxic than phenol preparations. However, part of the pain-relieving effect of compounds containing dilute phenol might also be due to its toxic action on nociceptors [24].


    13.7 Regenerative Medicine



    13.7.1 Platelet Rich Plasma


    The application of biologic treatments for musculoskeletal disorders is growing significantly. Platelet rich plasma (PRP) is an autologous biologic treatment utilizing the patients’ own blood plasma. The process involves injection of platelet derived growth factors that are obtained via density gradient centrifugation to remove plasma and red blood cells and to increase platelet concentration [25]. Platelets are well-known mediators of the coagulation cascade, however they also have hundreds of bioactive cytokines and growth factors that act via autocrine and paracrine mechanisms to enhance cell interaction and healing [26]. The rationale for the use of PRP is to stimulate tissue regeneration and the natural healing cascade by releasing these growth factors directly into the area of tissue damage [27].

    It is important to mention that not all PRP preparations are the same and formulations vary in the concentration of platelets and leukocytes. This variability has made it difficult to compare PRP treatments between investigational studies. A classification system has been proposed that incorporates white blood cell concentration (increased vs. not increased over baseline), platelet concentration (greater or less than 5 times baseline), and platelet activation status [28]. Such classification allows researchers to standardize formulations of PRP for various treatment populations.

    More substantiated clinical data is needed to improve our understanding of the best use of this treatment modality. Further research efforts are aimed at determining appropriate indications, type of PRP formulation, and timing/number of injections. Currently accepted indications for PRP include the treatment of chronic tendinopathies, muscle strains, and ligament injuries that have been resistant to standard medical and rehabilitative therapies [2933]. More research is also needed to determine if there is a role for PRP to treat acute sports injuries in order to speed recovery and decrease the time missed from athletic competition [34, 35].

    PRP is also being investigated as a tool for the management of knee osteoarthritis . An increasing number of clinical trials show increased function and decreased pain in the treatment of the arthritic knee [3639]. With regard to osteoarthritis treatment, PRP is being looked at for its potential to increase anabolic effect on chondrocytes and a decrease catabolic effect in the inflammatory environment [40]. A meta-analysis on the use of PRP for the treatment of knee arthritis demonstrated better pain relief and functional improvement when compared to hyaluronic acid and placebo [41]. While the use of PRP in treatment of knee osteoarthritis seems promising, randomized controlled studies need to be initiated to explore the efficacy in other joints such as the hip.


    13.7.2 Mesenchymal Stem Cells


    Mesenchymal stem cells (MSCs) are another therapy which has received increased attention for not only musculoskeletal care but also in many areas of regenerative medicine. MSCs are being considered as a potential treatment for osteoarthritis because of their healing potential and anti-inflammatory effects [42]. Animal studies with MSCs used in the treatment of osteoarthritis show potential to slow down the progression of cartilage degeneration [4346]. MSCs can modulate the inflammatory response , inhibit apoptosis, stimulate cell repair, and improve blood flow to joints [47]. By secreting paracrine factors, including cytokines and growth factors, MSCs can target injured tissues leading to a trophic effect that can initiate endogenous tissue repair [48].

    MSCs are easily found in various tissue sources including bone marrow, adipose cells, periosteum, umbilical cord tissue, and synovial tissue [49]. MSCs have the capacity to differentiate into a variety of cell types. Bone marrow derived MSCs can differentiate into cells of chondrogenic lineage [46].

    FDA guidelines explicitly dictate the extent to which stem cell-based therapies may be administered in clinical practice in the USA. FDA Tissue Regulation, 21 CFR Part 1271, outlines the guidelines for cell-based therapies that may be used by clinicians. These guidelines require that cells “be minimally manipulated,” “used within a short period of time,” and “be used only at the point of care.” Minimal manipulation of cells at present does not allow for extended ex-vivo culturing of cells and treatment with growth factors [49, 50].

    MSCs are in their infancy with respect to their role in modulating pain and the potential for treating articular cartilage degeneration . Well-designed clinical studies are needed to not only determine efficacy, but also to determine variables such as optimal concentration of MSCs , best source to harvest them, and the safety of both autologous and allogenic sources [51, 52].


    13.8 Safety Considerations


    The procedures described in this chapter are by-and-large considered minimally invasive. However, this does not mean that they are totally without risk. Informed consent should always be obtained for any procedure irrespective of the relative risks. Discussion with the patient should include the indications, anticipated outcome, potential risks and complications, possible side effects, and alternatives to the procedure. Patients should sign documentation that informed consent was given and understood. The documentation should be kept as part of the patient’s record.


    13.9 Contraindications


    Contraindications to injections include an active infection or allergy to the products used. Anticoagulated state/coagulopathy is a relative contraindication. The procedures described in this chapter are generally considered low risk and can be performed while a patient is on blood thinning products. However, if a patient is on warfarin an INR should be checked to exclude the possibility of a supratherapeutic level. An INR of less than 3.0 is reasonable cutoff for low risk, superficial, soft tissue injections. It is also important to assess for any underlying medical contraindications (such as uncontrolled diabetes or adrenal insufficiency) prior to performing corticosteroid injections.


    13.10 Potential Complications


    Intra-articular and periarticular steroid injections have been found to be safe and to have low complication rates if performed while taking adequate precautions [53, 54]. Potential complications that could result from joint and soft tissue procedures include: post procedural pain flair, subcutaneous fat atrophy, soft tissue calcification, tendon rupture, bleeding, infection, and allergic reaction [53]. These potential complications can be minimized with proper exclusion of patients with known contraindications as well as meticulous attention to injection site preparation and procedural technique.

    Injection site preparation is arguably the most important part of the procedure. Skin preparation can be performed with a variety of microbicides including alcohol, chlorhexidine and alcohol solutions, or povidone-iodine. One must allow the selected microbicide, time enough to kill the bacteria after application (1–2 min. is typically satisfactory, though for optimal bacteriocidal effects povidone–iodine products should be dry). Post-injection infection rates of 1:16,000 to 1–2:150,000 have been cited [12].

    Local reactions at the injection site may include swelling, tenderness, and warmth, all of which can develop a few hours after the injection and may last up to 2 days. A post-injection steroid flare, thought to be a crystal-induced inflammatory response caused by preservatives in the injectate, may occur within the first 24–36 h after injection [55]. This reaction is self-limited and symptomatic patients are instructed to apply ice packs for temporary amelioration. Also, failure to remove residual skin preparation may cause local skin irritation.

    Soft tissue (adipose) atrophy and local skin depigmentation are possible with any steroid injection into soft tissue, particularly at superficial sites and bony prominences where the subcutaneous adipose is less thick. Rarely, periarticular and soft tissue calcifications may occur, seemingly most preferentially at sites of multiple injections. The risk of tendon rupture can be reduced by taking great care to avoid intrasubstance injection of steroid into the tendon itself. The peritenon is the target tissue for treatment of tendonitis/tendinosis. To avoid direct needle injury to articular cartilage or local nerves, strict attention should be paid to anatomic landmarks and depth of the injection.

    Systemic effects are uncommon but may arise, particularly following injection into highly vascularized tissue (such as a site of prior surgery) or with inadvertent direct vascular injection. The proceduralist must be vigilant to reduce the potential for systemic side effects. Patients should remain in the office for an appropriate period of time following their procedure to monitor for adverse reactions. Typically 10 min will suffice with minor procedures. If large volumes of long-acting anesthetics are used, a lengthier period of observation should be instituted. Symptoms of vascular uptake of local anesthetic include lightheadedness, tinnitus, a metallic taste in the mouth, and perioral tingling. Patients who exhibit these symptoms should not be released home and should be moved to a setting where additional monitoring can be instituted to observe for signs of central nervous system and cardiotoxicity.

    Exogenous corticosteroids can have an effect on the endocrine system. Hyperglycemia can certainly occur following corticosteroid injection in patients with diabetes [23], particularly if they typically exhibit poor glycemic control or require high doses of insulin for management. All diabetics should be counseled regarding this possibility and given instructions for frequent glucose monitoring for the first several days following the injection. Other rare, but reported, complications include adrenal suppression and abnormal uterine bleeding [13, 56]. A benign facial flush can occur for 1–3 days following corticosteroid injections and is not considered an allergic reaction in the absence of other symptoms such as hives, shortness of breath, or pruritus.


    13.11 Anatomy


    Surface anatomy landmarks that are palpable and help guide injections into the hip and pelvic region include the ilium with its large anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS), the greater trochanter, ischial tuberosity, and the coccyx. Palpable joints include the hip joint, sacroiliac joint, pubic symphysis, and the sacrococcygeal articulation. The sciatic notch is formed by the ilium and the lateral border of the sacrum. The proceduralist should have a detailed understanding of musculoskeletal anatomy, including muscle attachments, bursa, nerves, and blood vessels. Hip and pelvic anatomy with common injection target tissues are depicted in Fig. 13.2.

    A140994_2_En_13_Fig2_HTML.gif


    Fig. 13.2
    Anterior view of the pelvis with common injection target tissues identified


    13.12 Procedures



    13.12.1 Documentation


    As previously discussed, the physician should review the rationale for the procedure and obtain written informed consent. In July 2004, the Joint Commission on the Accreditation of Healthcare Organizations (JCAHO ) began requiring providers to follow a universal protocol for preventing wrong site, wrong procedure, and wrong person surgery. The protocol’s three major elements include: (1) initial verification of the intended patient, procedure, and the site of the procedure; (2) marking the intended site with a sterile pen, where applicable; and (3) a final “time-out” immediately before beginning the procedure [57].


    13.12.2 Injection Technique Fundamentals



    13.12.2.1 Image Guidance


    Determine whether image guidance (if available) will be necessary to appropriately perform the procedure. For injections such as the hip joint, iliopsoas bursa, sacroiliac joint, piriformis muscle and pubic symphysis, image guidance is recommended.


    13.12.2.2 Positioning


    Position the patient in a comfortable manner that will allow easy access to the target anatomy.


    13.12.2.3 Target Selection


    Superficial anatomy is palpated and a needle entry point is marked.


    13.12.2.4 Sterile Preparation


    The area is generously prepped with a microbiocidal agent.


    13.12.2.5 Drapes


    Drapes can be used if necessary to maintain a sterile field, however, are not always necessary for routine soft tissue and joint injections that have been prepped in a wide fashion around the target anatomy.


    13.12.2.6 Universal Precautions


    Universal precautions should always be observed.


    13.12.2.7 Gloves


    Sterile gloves must be worn if the physician needs to palpate the needle entry site after it has been prepped or to touch the needle. This is often the case with novice proceduralists. For the experienced proceduralist, once the needle entry point is marked and prepped, the injection can typically be performed without touching (contaminating) the needle entry point or needle. Thus non-sterile gloves may be worn.


    13.12.2.8 Skin Wheal


    Injections are much more tolerable for the patient if the proceduralist takes time to perform a separate skin wheal with 1 % lidocaine at the needle entry point using a 30 gauge needle, and infiltrates a little lidocaine along the initial needle trajectory. When performing a skin wheal, infiltrate very slowly; this will minimize the initial burning pain associated with subcutaneous lidocaine. To further reduce the sting of local anesthetics, 1 ml of sodium bicarbonate (8.4 %) can be combined with 9 ml of 1 % lidocaine. Buffering lidocaine in this manner will also speed the onset of analgesia for deeper subcutaneous and intramuscular/intra-articular injections. Patients will return for further procedures if they know their physician has excellent technique and causes them minimal pain.

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    Dec 2, 2017 | Posted by in SPORT MEDICINE | Comments Off on Nonsurgical Interventions

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