Reliability of common knee injection sites with low-volume injections

The Journal of Arthroplasty Vol. 19 No. 7 2004

Reliability of Common Knee Injection Sites With Low-Volume Injections William M. Wind, Jr., MD, and Robert J. Smolinski, MD

Abstract: This study’s purpose was to evaluate the reliability of knee injection sites with low-volume (2–3cc) injection typical of viscosupplementation. This was a prospective study of 131 knees randomly assigned to 3 injection groups before to knee arthroscopy: SM-superomedial, superolateral, and lateral joint line (LJL). Needles were inserted to the hub, and aspiration was attempted before injection with 3 cc diluted methylene blue (MB). Injections then were graded at the time of arthroscopy as good, fair, or poor, depending on the intra-articular staining of MB. We conclude that a lateral joint line injection site may not be reliable for routine injections of low volumes into knees, because it results in good intra- articular delivery less than half of the time, with a high incidence of soft-tissue infiltration. Key words: viscosupplementation, knee injection, knee arthroscopy, methylene blue. © 2004 Elsevier Inc. All rights reserved.

A common office procedure performed by orthopedic surgeons and other physicians is an intraarticular injection of corticosteroid. More recently, viscosupplementation with hyaluronic acid preparations has become popular for the management of arthritic conditions of the knee [1–3]. Although a number of clinical trials are being performed regarding the efficacy of these procedures [4 –14], there is little consensus in the literature on the appropriate technique of intra-articular administration resulting in the most reliable results. Although an injection of the knee seems to be a relatively simple procedure, it may be difficult to assess whether the tip of the needle lies free in the

joint or is embedded in synovium or soft tissue before administration of the preparation of hyaluronic acid. Therefore, the purpose of this study was to determine the most reliable site for the intraarticular delivery of the small-volume injections that are typical of viscosupplementation.

Materials and Methods A prospective, randomized study of 131 consecutive patients presenting for routine knee arthroscopy over a 4-month period were enrolled in the study. Patients requiring reconstructive or open knee procedures were excluded. The age of the patients ranged from 18 to 60 years. Following institutional review board approval and informed consent regarding the study, each patient was randomly assigned to 1 of 3 injection sites. Patients were randomized consecutively into sites chosen for injection that were believed to be the sites typically used by most physicians for knee aspirations and injections. These included the superomedial, superolateral, and lateral joint line (LJL) areas (Fig. 1).

From the Department of Orthopaedic Surgery, Sports Medicine Institute, State University of New York at Buffalo, Buffalo, New York. Submitted June 26, 2002; accepted February 27, 2004. No benefits or funds were received in support of this study. Reprint requests; Dr. William M. Wind, Jr., State University of New York at Buffalo, Department of Orthopaedic Surgery, Sports Medicine Institute, 162G Farber Hall, 3435 Main Street, Buffalo, New York 14214. © 2004 Elsevier Inc. All rights reserved. 0883-5403/04/1907-0008$30.00/0 doi:10.1016/j.arth.2004.02.042

858

Knee Injection Sites • Wind, Jr. and Smolinski

859

Fig. 1. (A) Schematic of the right knee demonstrating the superomedial and superolateral injection sites. These injections are performed with the knee extended. (B) Schematic of the right knee flexed 90° and demonstrating the LJL injection site.

The superomedial and superolateral injection sites were defined as the intersection point 1 cm medial or lateral to the patella and the junction of the superior one third and inferior two thirds of the patella, respectively. The injection technique involved placing an 18-gauge, 1.5 in needle at the above sites and aiming the needle at an angle of 45° directed toward the center of the joint with the knee in full extension. The inferior joint line site was defined as that typically used for the viewing portal during arthroscopy. It was located just above the joint line and lateral to the patellar tendon. The inferior joint line injections were performed with the knee at 90° of flexion and the needle tip aiming toward the femoral notch. In each case, a preparation of diluted methylene blue (MB) was prepared by combining 0.1 cc of methylene blue with 3 cc of normal saline. The solution then was mixed to produce a uniform consistency throughout the syringe. At the time of surgery, the knee was first prepped and draped in the standard fashion. Before introduction of the arthroscope, the knee was aspirated to remove any effusion and randomly injected with 3 cc of diluted MB mixture into 1 of the 3 previously described sites. The knee then was placed through a range of motion 10 times in an attempt to disseminate the dye within the joint. A standard LJL portal then was created for the introduction of the arthroscope. The knee then was distended to 30 mm Hg using an arthroscopic pump and examined intra-articularly for evidence of MB staining of the joint. The MB staining of the knee joint was graded in each case by a single examiner at the time of initial arthroscopy into the following categories: good, dif-

fuse intra-articular MB, uniform staining throughout the joint; fair, some intra-articular MB, sporadic/scant staining of the joint; poor, no intra-articular MB.

Results All 131 patients consented for and completed the study. None of the patients were excluded because of conversion to an open procedure at the time of surgery. The average age of the patient population was 43 years (range, 18 – 80 years). Of the 131 knees that were randomly divided among the 3 injection sites, 44 patients had inferior LJL injections, 44 had superolateral, and 43 superomedial injections of the MB dye. Before injection, all knees with an effusion (30 of 131) were aspirated to equalize the joint volume among the patients. For superomedial and superolateral injections, intra-articular MB dye was found in all but 1 case (2%) from the superomedial injection site (Table 1). In superomedial injections, 93% of knees were graded good with diffuse and uniform staining on

Table 1. Results of Intra-Articular Methylene Blue Staining Following Knee Injection From 3 Different Sites Injection Site Result Superolateral Superomedial Lateral Joint Poor Fair Good Total

0 5 (11%) 39 (89%) 44

1 (2%) 2 (5%) 40 (93%) 43

17 (39%) 8 (18%) 19 (43%) 44

Total 18 (14%) 15 (11%) 98 (75%) 131

860 The Journal of Arthroplasty Vol. 19 No. 7 October 2004 inspection with the arthroscope. Only 5% showed trace/scant staining and were graded as fair. Superolateral joint line injections yielded similar, albeit slightly inferior, results. Eighty-nine percent of knees yielded good results with diffuse staining and 11% trace staining (fair). The results of LJL injections were much less successful than superior injections. LJL injections were rated good in only 43% of cases, with 18% demonstrating a trace amount of dye in the joint (fair) and a large percentage (39%) with no intra-articular staining (poor). In the majority of knees with fair and poor results, internal staining of the fat pad or synovium was seen at arthroscopy. The extent of diffusion was analyzed using Kruskal-Wallis analysis of variance, with a MannWhitney post-hoc analysis. There was a significantly lower extent of diffusion for injections at the infrapatellar site compared with the superolateral and supermedial sites (P⬍.001). Injections at the superolateral and superomedial sites did not differ significantly with respect to extent of diffusion.

Discussion Injecting and aspirating the knee is a relatively common and simple procedure used by many orthopedic surgeons and other physicians for both diagnostic and therapeutic purposes. Although they are common procedures, little has been published regarding the most reliable technique. Physicians may at times experience difficulty aspirating a joint because of synovial tissue occluding the tip of the needle. Likewise, when injecting the knee, especially a knee without an effusion, it may be difficult to determine whether the needle tip lies freely within the joint or is embedded in synovium. These problems usually are overcome by the larger volume of injectables used and the pressure from the syringe pushing soft tissue away from the needle tip on injection. Ideally, in the instance of osteoarthritis, for example, the corticosteroid preparation is dispersed throughout the joint on injection for maximum efficacy. In the case in which the corticosteroid is not injected intra-articularly, but rather into soft tissue, it may not be as effective. In one review of intra-articular corticosteroid therapy, 30% of knee joint injections missed the intra-articular space [15]. Recently, hyaluronic acid preparations have become popular for the treatment of knee osteoarthritis. When compared with corticosteroid injection and nonsteroidal anti-inflammatory medications, hyaluronic acid has shown an improvement in pain

scores in some studies [1,16 –18]. However, one large, randomized trial failed to demonstrate any beneficial effect of hyaluronate therapy [12]. The majority of evidence regarding hyaluronate therapy has shown moderate symptom improvement without the potential harmful effects on articular cartilage seen with corticosteroid injections [4,19]. There are a number of factors that emphasize the importance of accurate intra-articular injections, especially with hyaluronic acid. First, manufacturers recommend that a small volume (2–3 cc) of the viscous preparation be injected intra-articularly without dilution [20,21]. This low volume may make it more difficult to achieve the desired effect if the needle tip is embedded in synovium. In addition, the small volume may not be expelled as easily as larger volumes, which may dissipate into the joint through soft tissue secondary to the injection pressure of the syringe. Secondly, the significantly higher cost of hyaluronic acid injections and the requirement for multiple injections increase the desirability that the preparation is delivered intra- articularly for maximum effect [1,20,21]. Third, adverse reactions secondary to hyaluronic acid injections can occur but are rare [1,7,20 –24]. The findings of one large, multicenter, Canadian study indicated that when the intra-articular space is missed during viscosupplementation injection, the rate of local flare reactions increases [17,25]. Patients who developed local reactions, however, may still demonstrate clinical improvement [25]. The incidence of local reactions depended on the injection site, with the highest percentage of complications occurring with a medial approach and the knee bent. The authors suggested that different injection sites might affect the incidence of injection complications [25]. Finally, the results of this study indicate that arthroscopic visualization of low volumes of MB used to simulate hyaluronic acid injections demonstrated significant differences between injection sites around the knee. Some intra-articular MB was found in almost all cases of superomedial and superolateral injection sites. With diffuse, uniform staining seen with the MB injection, one would expect a similar small volume of hyaluronic acid to disseminate intra-articularly and achieve its desired effect. On the other hand, LJL injections with the knee bent did not reliably stain the joint with MB. Less than half of the attempts were completely successful with uniform staining of the joint. In the majority of fair or poor results, internal staining of the fat pad or synovium was seen, indicating that the

Knee Injection Sites • Wind, Jr. and Smolinski

needle tip was not free within the joint space before injection. Other authors have had similar difficulty aspirating and injecting from the lateral joint line [26]. In those situations, which they encountered about 25% of the time, they recommended injecting 5 mL of air into the joint and then palpating along the capsular wall to determine the location of the intra-articular space [26]. In theory, then, with hyaluronic acid injections at this location, one may encounter difficulty with obtaining a true intra-articular injection. We conclude that the superomedial and superolateral joint line injection sites are reliable for the intraarticular injection of small volumes of fluid. LJL injections with the knee bent result in a higher percentage of fat pad or synovial interference with extrusion of MB. These results are important to consider when injecting knees, especially with low-volume and expensive hyaluronic acid preparations.

References 1. Rosier RN, O’Keefe RJ: Hyaluronic acid therapy. Instr Course Lect 49:495, 2000 2. Adams M: Viscosupplementation as an alternative to conventional treatment for the management of osteoarthritis of the knee. JCR 5(suppl):S18, 1999 3. American College of Rheumatology Subcommittee on Osteoarthritis Guidelines: Recommendations for the medical management of osteoarthritis of the hip and knee: 2000 update. Arthritis Rheum 43:1905, 2000 4. Peyron JG: Intraarticular hyaluronan injections in the treatment of osteoarthritis: state-of-the-art-review. J Rheumatol 39(suppl):10, 1993 5. Dixon AS, Jacoby RK, Berry H, et al: Clinical trial of intra-articular injection of sodium hyaluronate in patients with osteoarthritis of the knee. Curr Med Res Opin 11:205, 1988 6. Grecomoro G, Martorana U, Di Marco C: Intra-articular treatment with sodium hyaluronate in gonarthrosis: a controlled clinical trial versus placebo. Pharmatherapeutica 5:137, 1987 7. Adams ME: An analysis of clinical studies of the use of crosslinked hyaluronan, hylan, in the treatment of osteoarthritis. J Rheumatol 39(suppl):16, 1993 8. Dougados M, Nguyen M, Listrat V, et al: High molecular weight sodium hyaluronate (hyalectin) in osteoarthritis of the knee: a 1 year placebo-controlled trial. Osteoarthritis Cartilage 1:97, 1993 9. Wobig M, Dickhut A, Maier R, et al: Viscosupplementation with hylan G-F 20: a 26-week controlled trial of efficacy and safety in the osteoarthritic knee. Clin Ther 20:410, 1998 10. Lohmander LS, Dalen N, Englund G, et al: Intraarticular hyaluronan injections in the treatment of osteoarthritis of the knee: a randomized, double blind, placebo controlled multicentre trial. Hyaluro-

11.

12.

13.

14.

15.

16.

17.

18.

19. 20. 21.

22.

23.

24.

25.

26.

861

nan Multicentre Trial Group. Ann Rheum Dis 55: 424, 1996 Puhl W, Scharf P: Letter: Intra-articular hyaluronan treatment for osteoarthritis. Ann Rheum Dis 56:441, 1997 Henderson EB, Smith EC, Pegley F, et al: Intraarticular injections of 750 kD hyaluronan in the treatment of osteoarthritis: a randomized single center double-blind placebo-controlled trial of 91 patients demonstrating lack of efficacy. Ann Rheum Dis 53:529, 1994 Altman RD, Moskowitz R: Intraarticular sodium hyaluronate (Hyalgan) in the treatment of patients with osteoarthritis of the knee: a randomized clinical trial. Hyalgan Study Group. J Rheumatol 25:2203, 1998 Wobig M, Dickhut A, Maier R, et al: Viscosupplementation with hylan G-F 20: a 26-week controlled trial of efficacy and safety in the osteoarthritic knee. Clin Ther 20:410, 1998 Jones A, Regan M, Ledingham J, et al: Importance of placement of the intra-articular steroid injection. BMJ 307:1329, 1993 Leardini G, Mattara L, Franceschini M, et al: Intraarticular treatment of knee osteoarthritis: a comparative study between hyaluronic acid and 6-methyl prednisolone acetate. Clin Exp Rheumatol 9:375, 1991 Adams ME, Atkinson MH, Lussier AJ, et al: The role of viscosupplementation with hylan G-F 20 (Synvisc) in the treatment of osteoarthritis of the knee: a Canadian multicenter trial comparing hylan G-F 20 alone, hylan G-F 20 with non-steroidal anti-inflammatory drugs (NSAID’s) and NSAID’s alone. Osteoarthritis Cartilage 3:213, 1995 Jones AC, Pattrick M, Doherty S, et al: Intra-articular hyaluronic acid compared to intra-articular triamcinolone hexacetonide in inflammatory knee osteoarthritis. Osteoarthritis Cartilage 3:269, 1995 Rozental TD, Sculco TP: Intra-articular corticosteroids: an updated review. Am J Orthop 29(1):18, 2000 Hylan G-F 20 (Synvisc) [package insert]. Ridgefield, NJ: Wyeth-Ayerst Pharmaceuticals; May 1999 Sodium Hyaluronate (Hyalgan) [package insert]. Abano Terme, Padua (PD), Italy: Sanofi-Synthelabo Inc.; September 2000 Puttick MP, Wade JP, Chalmers A, et al: Acute local reactions after intraarticular hylan for osteoarthritis of the knee. J Rheumatol 22:1311, 1995 Maillefert JF, Hirschhorn P, Pascaud F, et al: Acute attack of chondrocalcinosis after an intraarticular injection of hyaluronan. Rev Rhum Engl Ed 64:593, 1997 Luzar MJ, Altawil B: Pseudogout following intraarticular injection of sodium hyaluronate. Arthritis Rheum 41:939, 1998 Lussier A, Cividino AA, McFarlane CA, et al: Viscosupplementation with hylan for the treatment of osteoarthritis: findings from clinical practice in Canada. J Rheumatol 23:1579, 1996 Marshall KW: Intra-articular therapy in knee osteoarthritis: the role of viscosupplementation. Am J Orthop 30(suppl):23, 2001