How to Inject the Synovial Cavities of the Digit

Transcription

1 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS How to Inject the Synovial avities of the Digit John Schumacher, DVM, MS, Diplomate AVIM*; and ay Wilhite, PhD Authors addresses: Equine Sports Medicine Program (Schumacher) and Department of Anatomy and Physiology (Wilhite), ollege of Veterinary Medicine, Auburn University, Auburn, A 36849; schumjo@auburn.edu. *orresponding and presenting author AAEP. 1. Introduction Arthrocentesis of the equine interphalangeal joints and synoviocentesis of the digital synovial sheath is commonly performed for diagnostic analgesia as part of a lameness examination and to medicate these structures. The techniques for arthrocentesis are the same for the forelimb and the hind limb. estraint is achieved by applying a lip twitch to the horse. Tranquilization or sedation is rarely used for restraint when centesis of these structures is part of a lameness examination, but in some cases tranquilizing or sedating the horse may be necessary to increase the safety of the procedure. Administration of a low dose of xylazine, detomidine, or acepromazine is unlikely to interfere with gait evaluation 1 4 and in some cases may even accentuate lameness. If centesis is performed with the foot bearing weight, the contralateral limb can be held by an assistant. Some horses, however, may buckle at the carpus when the needle is inserted, causing injury if the carpus strikes the ground. 2. Materials and Methods Arthrocentesis of the Distal Interphalangeal Joint At least 6 approaches to the distal interphalangeal (DIP) joint have been described: the dorsal perpendicular, the dorsal parallel, the dorsal inclined, the dorsolateral, the lateral, and the palmar approaches. A 20- or 21-gauge, 1- to 1.5-inch (2.54- to 3.8-cm) needle is commonly used for arthrocentesis of the DIP joint. A 20-gauge, 3.5-inch (9-cm) spinal needle is used for the palmar approach. When using a dorsal approach to the DIP joint, the limb can be held or bearing weight (Fig 1). Dorsal Perpendicular and Dorsolateral Approaches to the DIP Joint For the dorsal perpendicular approach, the needle is inserted at the proximal edge of the coronet, approximately 0.75 inch ( 2 cm) lateral or medial to the midpoint of the coronet (ie, at the edge of the extensor tendon) (Fig. 2). The needle is directed distally, perpendicular to the bearing surface of the hoof. 5 A slight variation of the dorsal perpendicular approach is the dorsolateral approach, in which the needle is inserted at the same site and directed beneath the extensor tendon, aiming for the middle sagittal plane of the foot behind the extensor process of the distal phalanx (Fig. 3). 5 9 Depth of penetration is about 1 inch (2.54 cm). Synovial fluid usually appears in the needle hub, but accuracy of needle placement can also be determined by ease of injection. After injection, the syringe may refill when pressure on the plunger is released. F1 F2 F3 NTES Vol. 58 AAEP PEEDINGS rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

2 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS F4 F5 F6 Fig. 1. When using a dorsal approach to the distal interphalangeal (DIP) joint, the limb can be held or bearing weight. Dorsal Parallel Approach to the DIP Joint For a dorsal parallel approach, the needle is inserted parallel to the bearing surface of the foot through or immediately proximal to the coronary band (Fig. 4). In the primary author s experience, firm digital pressure at the site of arthrocentesis immediately before insertion of the needle may lessen the horse s reaction to the procedure. The needle can be inserted on the middle sagittal plane or slightly medial or lateral to this plane. The needle passes through the digital extensor tendon to enter the dorsal pouch of the DIP joint, which covers most of the dorsal aspect of the middle phalanx. Inserting the needle too far proximal to the coronary band for a parallel approach may result in arthrocentesis of a distodorsal pouch of the proximal interphalangeal joint (Fig. 5). We are unaware of any reports of complication caused by needle puncture of the digital extensor tendon other than a report of mineralization in the tendon at the site of injection. 10 Gandini 11 speculated that administration of corticosteroid (with subsequent leakage at the injection site) may be the cause of this complication. If mineralization of the digital extensor tendon is a potential complication of arthrocentesis of the DIP joint, its occurrence probably is insignificant. Using a variation of the dorsal parallel approach, the dorsal inclined approach, a needle is inserted perpendicular to the skin surface immediately proximal to the coronary band (Fig. 6). This approach, reported by Kaneps, 12 was found to be Fig. 2. For the dorsal perpendicular approach to the DIP joint, the needle is inserted at the proximal edge of the coronet, approximately 0.75 inch ( 2 cm) lateral or medial to the midpoint of the coronet (ie, at the edge of the extensor ligament). The needle is directed distally, perpendicular to the bearing surface of the hoof. more accurate and easier to perform than was the dorsal perpendicular or dorsolateral approaches for accessing the DIP joint. 11 ateral Approach to the DIP Joint The DIP joint also can be entered using a lateral approach. 13,14 This approach appears to elicit less reaction than other approaches. The landmark for needle insertion is a depression in the proximal border of the lateral collateral cartilage palpated near the palmar border of the middle phalanx (Fig. 7). A 1-inch (2.54-cm), 20- to 22-gauge needle is inserted through the skin, just above the palpable depression in the proximal edge of the lateral collateral cartilage. The needle is directed medially at a 45 angle distally and 20 palmar to penetrate the palmar pouch of the DIP joint (Fig. 8). The proximopalmar pouch of the DIP joint is entered, usually at a depth of penetration less than 1 inch (2.54 cm). Using the lateral approach to the DIP joint, the navicular bursa or digital tendon sheath is often inadvertently entered if the needle is inserted palmar to the rec- AAEP PEEDINGS Vol F7 F8 rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

3 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS Fig. 3. For a dorsolateral approach to the DIP joint, the needle is inserted at the proximal edge of the coronet, approximately 0.75 inch ( 2 cm) lateral or medial to the midpoint of the coronet (ie, at the edge of the extensor ligament). The needle is directed distally beneath the ligament at an angle aiming for the middle sagittal plane of the foot, behind the extensor process of the distal phalanx. Fig. 4. For a dorsal parallel approach to the DIP joint, the needle is inserted near or on the midline, parallel to the bearing surface of the foot through or immediately proximal to the coronary band. (Fig. 9). The advantages cited for using this technique are less vascularity of periarticular structures and the large size of the palmar pouch of the DIP joint. bvious disadvantages of a palmar approach are that the deep digital flexor tendon must be penetrated to access the joint and the close prox- F9 ommended site of insertion, particularly if a needle longer than 1 inch (2.54 cm) is used, or if the procedure is performed with the limb held in a flexed position. 13,14 The lateral approach appears to be accurate for arthrocentesis of the DIP joint only when a needle no longer than 1 inch is inserted with the horse standing squarely. 14 Palmar Approach to the DIP Joint A palmar approach to the DIP joint was described by McIlwraith and Goodman, 15 who cited a report of the procedure described in a German publication. 10 In the German publication, complication of periosteal reaction at the site of capsular attachment on to the distal phalanx and hemorrhage associated with a dorsal perpendicular approach to the DIP joint prompted investigation of a palmar approach to the DIP joint. 10 The site for injection is a point on the palmar midline slightly proximal to the deepest indentation of the fossa proximal to the bulbs of the heel. A 3.5-inch (9-cm) spinal needle is directed dorsally aiming for a point halfway between the coronet and the bearing surface of the hoof at the toe Vol. 58 AAEP PEEDINGS Fig. 5. Inserting the needle too far proximal to the coronary band for a parallel approach to the DIP joint may result in arthrocentesis of a distodorsal pouch (arrow) of the proximal interphalangeal joint. rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

4 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS Fig. 6. To perform the dorsal inclined approach to the DIP joint, a needle is inserted near or on the midline, perpendicular to the skin surface immediately proximal to the coronary band. Fig. 8. For the lateral approach to the DIP joint, a 1-inch (2.54- cm), 20- to 22-gauge needle is inserted through the skin, just above the palpable depression in the proximal edge of the lateral collateral cartilage. The needle is directed medially at a 45 angle distally and 20 palmar to penetrate the palmar pouch of the DIP joint. Fig. 7. The landmark for needle insertion for a lateral approach to the DIP joint is a depression in the proximal border of the lateral collateral cartilage palpated near the palmar border of the middle phalanx. imity of the navicular bursa. We are unaware of any studies that have examined the accuracy of this approach. The clinician should be aware that administration of 5 or 6 m of local anesthetic solution into the DIP joint desensitizes not only the DIP joint but also the toe region of the sole and the navicular bone and its supporting structures When a large volume (ie, 10 m) of local anesthetic solution is administered into the DIP joint, the palmar portion of the sole is also desensitized. 19 Arthrocentesis of the Proximal Interphalangeal Joint At least four approaches to the proximal interphalangeal (PIP) (pastern) joint have been described. These include a dorsal approach, 6,7,20 a dorsolateral approach, 5,8,20 a palmaroproximal approach, 21 and a lateral approach. 22 Synovial fluid is frequently observed with the palmaroproximal and lateral approaches 21,22 but is observed rarely using the other approaches. Three of these four methods for arthrocentesis of the PIP joint were evaluated for accuracy by Poore et al, who found that students inexperienced in arthrocentesis of the PIP joint were only 32%, 48%, and 36% successful when performing the dorsal, dorsolateral, and palmaroproximal ap- AAEP PEEDINGS Vol rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

5 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS F10 Fig. 9. The site for injection for the palmar approach to the DIP joint is a point on the palmar midline slightly proximal to the deepest indentation of the fossa proximal to the bulbs of the heel. A 3.5-inch (9-cm) spinal needle is directed dorsally, aiming for a point halfway between the coronet and the bearing surface of the hoof at the toe. proaches, respectively. 23 The lateral approach was not evaluated in this study. A 20-gauge, 1.5-inch (3.8-cm) needle is used for the dorsal and dorsolateral approaches, but a 1-inch (2.5-cm) needle is sufficient for the lateral and palmaroproximal approaches. The palmaroproximal approach is performed with the limb held, and the lateral approach is performed with the limb bearing weight. The dorsal and dorsolateral approaches to the PIP joint can be performed with the limb held or bearing weight. Dorsal Approach to the PIP Joint To perform the dorsal approach to the PIP joint as described by Wheat, 7 the needle is inserted on the dorsal midline about 1 cm distal to an imaginary line drawn between the medil and lateral eminences for attachment of the collateral ligaments on the distal end of the proximal phalanx (Fig. 10) and is directed obliquely distally and medially. To perform the dorsal approach to the PIP joint as described by Stashak, 20 the needle is inserted on the dorsal midline one-half inch (1.3 cm) proximal to the imaginary line between the medial and lateral eminences on the distal end of the proximal phalanx and directed slightly distally and slightly medially (Fig. 10). Dorsolateral Approach to the PIP Joint To perform the dorsolateral approach as described by Gabel, 6 the PIP joint is entered by placing a Vol. 58 AAEP PEEDINGS Fig. 10. To perform the dorsal approach to the PIP joint as described by Wheat 6 (needle A), the needle is inserted on the dorsal midline about 1 cm distal to an imaginary line drawn between the medial and lateral eminences for attachment of the collateral ligaments on the distal end of the proximal phalanx and is directed obliquely distally and medially. To perform the dorsal approach to the PIP joint as described by Stashak 19 (needle B), the needle is inserted on the dorsal midline one-half inch (1.3 cm) proximal to the imaginary line between eminences and directed slightly distally and slightly medially. needle at the lateral edge of the common digital extensor tendon, about one-half inch (1.3 cm) off the middle sagittal plane of the limb on an imaginary line drawn between the medial and lateral eminences for attachment of the collateral ligaments on the distal end of the proximal phalanx (Fig. 11). The needle is directed obliquely distally and medially toward the dorsal midline. A variation of this approach is to insert the needle about one-half inch (1.3 cm) below the imaginary line drawn between the medial and lateral eminences for attachment of the collateral ligaments on the distal end of the proximal phalanx, one-half inch (1.3 cm) from the middle sagittal plane of the limb and to direct the needle medially, parallel to the ground (Fig. 11). 5 ateral Approach to the PIP Joint To perform the lateral approach as described by anonici, 22 the PIP joint is entered by inserting the needle directly through the lateral collateral ligament midway between the eminences for the attachment of the collateral ligament on the proximal and middle phalanges. The needle is directed in a slightly proximal to distal direction (Fig. 12). Synovial fluid usually flows from the needle to indicate that the needle has entered the joint. We are unaware of studies comparing the efficacy of this approach to the PIP joint with other approaches to the F11 F12 rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

6 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS Fig. 11. To perform the dorsolateral approach to the PIP joint, a needle is placed at the lateral edge of the common digital extensor tendon, about one-half inch (1.3 cm) from the center of an imaginary line drawn between the medial and lateral eminences for attachment of the collateral ligaments on the distal end of the proximal phalanx. The needle (A) is directed obliquely distally and medially toward the dorsal midline. A variation of this approach is to insert the needle about one-half inch (1.3 cm) below the imaginary line drawn between the medial and lateral eminences for attachment of the collateral ligaments, one-half inch (1.3 cm) from the dorsal midline and to direct the needle (B) medially, parallel to the ground. Fig. 12. To perform the lateral approach to the PIP joint, a needle is inserted directly through the lateral collateral ligament midway between eminences for the attachment of the collateral ligament on the proximal and middle phalanges. The needle is directed in a slightly proximal-distal direction. F13 F14 joint or reports of complications associated with placing a needle directly through the collateral ligament of the joint. Dorsolateral Approach to the PIP Joint To perform the palmaroproximal approach to the PIP joint as described by Miller et al, 21 the needle is inserted into a V -shaped depression formed by the palmar aspect of the proximal phalanx dorsally and the lateral branch of the superficial flexor tendon as it inserts on the middle phalanx palmarodistally (Fig. 13). The needle is directed distomedially at an angle of 30 from the transverse plane. The palmaroproximal approach was found to be often inaccurate, with inadvertent injection of the digital synovial sheath when attempted by veterinary students without prior experience. 23 Palmarolateral Approach to the PIP Joint A palmarolateral approach to the PIP joint was reported by Moyer and arter, who described the site of needle insertion to be immediately proximal to the transverse bony prominence on the proximopalmar border of the middle phalanx. 5 The needle is inserted perpendicular to the sagittal plane close to the palmar border of the proximal phalanx (Fig. 14). To our knowledge, accuracy of the palmarolateral approach has not been investigated. Synoviocentesis of the Digital Synovial Sheath The digital synovial sheath can be entered at any of the lateral pouches evident along its length, which is from the distal portion of the third metacarpus/ metatarsus to the palmar aspect of the proximal half of the middle phalanx. When the sheath is effused, these pouches are visible in places where the sheath is not encased by annular ligaments (Fig. 15). Even when the sheath is not effused, it often can be entered on the palmar aspect of the pastern between the proximal and distal digital annular ligaments, where the deep digital flexor tendon lies close to the skin (Fig. 16). To access the pouch at this location, the point of the needle must remain superficial to the deep digital flexor tendon. The appearance of synovial fluid in the needle hub indicates successful synoviocentesis. A primary indication for synoviocentesis of the digital synovial sheath is diagnosis of and treatment for various traumatic, infectious, and inflammatory disorders of the sheath. 24 In these cases, the sheath is usually effused, thereby simplifying synoviocentesis. An additional indication for synoviocentesis is diagnostic analgesia, in which case, the sheath is often not effused, thus hampering synoviocentesis. The palmar axial sesamoidean approach to the digital synovial sheath described by Hassel et al was 100% accurate in accessing the sheath when the sheath was not distended with synovial fluid. 24 AAEP PEEDINGS Vol F15 F16 rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

7 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS Fig. 13. To perform the palmaroproximal approach to the PIP joint, the needle is inserted into a V -shaped depression formed by the palmar aspect of the proximal phalanx dorsally and the lateral branch of the superficial flexor tendon as it inserts on the middle phalanx palmarodistally. The needle is directed distomedially at an angle of 30 from the transverse plane. Fig. 15. When the digital synovial sheath is effused, pouches are visible in places where the sheath is not encased by annular ligaments. To perform the palmar axial sesamoidean approach to the digital synovial sheath, a 20-gauge, 1-inch (2.5-cm) needle is placed at the level of the midbody of the lateral proximal sesamoid bone, 3 mm axial to its palpable palmar border and immediately palmar to the palmar digital neurovascular bundle (Fig. 17). The needle is advanced through the skin and palmar annular ligament of the fetlock and directed at a 45 angle to the sagittal plane, aiming toward the central intersesamoidean region, F17 Fig. 14. To perform the palmarolateral approach to the PIP joint, the needle is inserted perpendicular to the sagittal plane close to the palmar border of the first phalanx proximal to the transverse boney prominence on the proximopalmar border of the middle phalanx Vol. 58 AAEP PEEDINGS Fig. 16. The digital synovial sheath can be entered at any of the pouches evident along its length. Even when the digital synovial sheath is not effused, it often can be entered on the palmar aspect of the pastern between the proximal and distal digital annular ligaments, where the deep digital flexor tendon lies close to the skin (needle A). rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

8 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS Figures 4, 7, 10, 13, 15, and 16 are adapted from Moyer W, Schumacher J, Schumacher J. A Guide to Equine Joint Injections and egional Anesthesia, courtesy of Dr. Amy Benz, Academic Veterinary Solutions. Fig. 17. To perform the palmar axial sesamoidean approach to the digital synovial sheath, the fetlock is flexed and a needle is placed at the level of the midbody of the lateral proximal sesamoid bone axial to its palpable palmar border and immediately palmar to the digital neurovascular bundle. The needle is advanced through the skin and annular ligament of the fetlock and directed at a 45 angle to the sagittal plane, aiming toward the central intersesamoidean region. to a depth of about 0.5 to 0.75 inch (1.3 to 1.9 cm). A possible disadvantage of this approach is that the needle is likely to penetrate the flexor tendons. 24 It is unlikely, in our experience, that penetration of the flexor tendons by the needle has any clinical significance. eferences 1. Dyson SJ, Kidd. omparison of responses to analgesia of the navicular bursa and intraarticular analgesia of the distal interphalangeal joint in 59 horses. Equine Vet J 1993;25: Buchner HH, Kübber P, Zohmann E, et al. Sedation and antisedation as tools in equine lameness examination. Equine Vet J Suppl 1999;30: oss MW. Movement. In: oss MW, Dyson SJ, editors. Diagnosis and Management of ameness in the Horse. St ouis: WB Saunders; 2003: Fürst AE. Diagnostic anaesthesia. In: Auer JA, Stick JA. Equine Surgery. 3rd ed. St ouis: Saunders Elsevier; 2006: Moyer W, arter GK. Techniques to facilitate intra-articular injection of equine joints, in Proceedings. Am Assoc Equine Pract 1996;42: Gabel AA. Administration of medicine. In: Bone JF, atcott EJ, Gabel AA, editors. Equine Medicine and Surgery. Wheaton, I: American Veterinary Publications, Inc; 1963: Wheat JD, Jones K. Selected techniques of regional anesthesia. Vet lin North [Am arge Anim Pract] 1981;3: iebold TW, Goble, D, Geiser D. arge Animal Anesthesia, Principals and Techniques. Ames, IA: Iowa State University Press; 1982: Stashak TS. Examination for lameness. In: Stashak TS, editor. Adams ameness in Horses. 5th ed. Philadelphia: ea and Febiger; 2002: Boening KJ. Komplikationen bei diagnostischen und chirurgischen Eingriffen am Hufgelink des Pferdes (omplications attending diagnostic and surgical operations on the hoof joint of horse). Der Praktische Tierarzt 1980;10: Gandini M. omparison of three dorsal techniques for arthrocentesis of the distal interphalangeal joint in horses. J Am Vet Med Assoc 2007;231: Kaneps AJ. Diagnosis of lameness. In: Hinchcliff KW, Kaneps AJ, Geor J, editors. Equine Sports Medicine and Surgery. Philadelphia: WB Saunders o; 2004: Vazquez, Stover SM, Taylor KT, et al. ateral approach for arthrocentesis of the distal interphalangeal joint in horses. J Am Vet Med Assoc 1998;212: Vazquez, Stover SM. omparison of six techniques for a lateral approach to the coffin joint, in Proceedings. Am Assoc Equine Pract 1998;44: Goodman N, Baker BK. ameness diagnosis and treatment in the Quarter Horse racehorse. Vet lin North Am [Equine Pract] 1990;6: Schebitz H. Podotrochlosis in the horse. Proc Am Assoc Equine Pract 1964;10: Pleasant S, Moll HD, ey WB, et al. Intra-articular anaesthesia of the distal interphalangeal joint alleviates lameness associated with the navicular bursa in horses. Vet Surg 1997;26: Schumacher J, Steiger, Schumacher J, et al. Effects of analgesia of the distal interphalangeal joint or palmar digital nerves on lameness caused by solar pain in horses. Vet Surg 2000;29: Schumacher J, Schumacher J, DeGraves F, et al. A comparison of the effects of two volumes of local analgesic solution in the distal interphalangeal joint of horses with lameness caused by solar toe or solar heel pain. Equine Vet J 2001; 33: Stashak TS. Diagnosis of lameness. In: Stashak TS, editor. Adams ameness in Horses. 4 th ed. Philadelphia: ea and Febiger; 1987: AAEP PEEDINGS Vol rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN:

9 HW T MAKE ATINA HIES F INTA-ATIUA INJETINS 21. Miller SM, Stover SM, Taylor KT, et al. Palmaroproximal approach for arthrocentesis of the proximal interphalangeal joint in horses. Equine Vet J 1996;28: anonici F. ateral approach for arthrocentesis of the proximal interphalangeal joint of the horse. Equine Pract 1997; 19: Poore AB, ambert K, Shaw DJ, et al. omparison of three methods of injecting the proximal interphalangeal joint in horses. Vet ec 168: Hassel DM, Stover SM, Yarbrough TB, et al. Palmar-plantar axial sesamoidian approach to the digital flexor tendon sheath in horses. J Am Vet Med Assoc 2000;217: Vol. 58 AAEP PEEDINGS rig. p. PEAT: Session PF: PE s: AA s: 4/olor Figure(s) ATN: