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Low conductivity irrigating solutions for arthroscopy
Arthroscopy:
The Journal
ef Arthroscopic
and Related Surgery 7(l): 105-107
Published by Raven Press. Ltd. 0 1991 Arthroscopy
Low Conductivity
Association of North America
Irrigating Solutions for Arthroscopy
Brian Reagan, M.D., Bertram Zarins, M.D., and Henry J. Mankin, M.D.
Summary: The purpose of this study was to find a nonconductive physiologic solution to use for arthroscopy when electrosurgery is performed. We studied the effect of several solutions on proteoglycan synthesis in bovine articular cartilage slices, and the effect of using an electrosurgical instrument in various solutions in bovine knee joints. Both HEPES buffer 0.3 M (N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid) (Sigma Chemical Company, St. Louis, Missouri) and glycerol 2.6% gave good results in both categories. The glycerol solution appears to be the best from those tested since it supported cartilage metabolism somewhat better and is far less expensive than HEPES solution. Thus, in the use of electrosurgery during arthroscopic procedures, solutions
such as Ringer’s lactate and saline are too conductive to be effective or safe. Distilled water is nonphysiologic. Glycerol 2.6% is safe and effective and supports articular cartilage metabolism reasonably well for up to 2 h. Key Words: Electrosurgery-Irrigating solutions.
M (N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid) (Sigma Chemical Company, St. Louis, Missouri) demonstrated acceptable physiologic properties in relation to articular cartilage and were sufficiently nonconductive to allow use of electrosurgery during the arthroscopic procedure.
we determined that Ringer’s lactate solution was more physiologic than normal saline for arthroscopy (1). Saline has an inhibiting effeet on articular cartilage metabolism (1,2). Ringer’s lactate supported articular cartilage metabolism better than any of the other ionic buffered solutions tested, with the exception of Ham’s F-12 medium as measured by short- and long-term chondrocyte growth in tissue culture. However, Ringer’s lactate and other solutions such as phosphate buffered saline have high conductive properties. A nonconductive solution is more desirable if electrosurgery is used during an arthroscopic procedure. The purpose of this study was to find a non- or minimally conductive irrigating solution that would still support the articular cartilage metabolism. We studied the effects of several nonelectrolytic solutions on proteoglycan synthesis in calf articular cartilage. We found that glycerol 2.6% and HEPES buffer 0.3 In a prior study,
MATERIALS AND METHODS Fresh bovine articular cartilage from an abattoir was sliced, washed, and incubated with modified Ham’s F-12 medium (Gibco) at 37°C for 8 h. The slices were then washed briefly with phosphate buffered saline and placed into screw cap test tubes containing 5.0 ml of the test solution, to which 5 pCi of radiosulfate (specific activity 221 mCilm&f; New England Nuclear) had been added. The slices were incubated at 37°C in duplicate with constant agitation. At the end of each incubation period, cartilage slices were harvested, washed with PBS, and lyophilized, and the dry weight measured using a Mettler Micro Balance. The cartilage slices were then solubilized in formic acid 88% at 6o”C, and, after an overnight digestion, placed into a liquid scintillation fluid (Aquasol 2, New England Nuclear) and counted in a liquid scintillation counter.
From the Orthopaedic Research Laboratories and the Sports Medicine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. Address correspondence and reprint requests to Dr. Bertram Zarins, Massachusetts General Hospital, Ambulatory Care Center, Suite 514, Boston, MA 02114, U.S.A. Presented at the annual meeting of the Arthroscopy Association of North America. San Francisco, March 21, 1986. 105
B. REAGAN
106
The results were recorded as cprn/t_r,gdry weight of tissue. The test solutions for the cartilage incubations were chosen either to serve as controls, as in our prior study (testing Ham’s F-12 medium or Ringer’s lactate) (I), or for their nonelectrolytic and nonconductive natures. The solutions included distilled water, glycerol 2.6%; Tris (hydroxymethyi) amino methane 0.3 M (Sigma); Dextran 40 (Rheomacrodex, Pharmacia); and N-2-hydroxyethylpiperazine iV’-2-ethanesulfonic acid 0.3 M (HEPES; Sigma), a material used in our laboratory for preparation of a cell-free messenger RNA-directed synthetic system. The osmolarity of each of these solutions was tested using freezing point depression, and conductivity was assessed using a conductivity meter. The characteristics of electrosurgery on grounded bovine knee joints were tested using various solutions. We used a Bovie Electrocautery unit, obtained from our operating room, at standard settings for “cutting” and “coagulation.” We placed the electrocautery stylus on the bovine synovial tissues bathed in the fluid and observed the results. We noted the efficiency of the electrosurgical system and the presence of sparking or caramelization of solutions. RESULTS Figure 1 shows the results of the metabolic study and demonstrates the superiority of Ham’s F-12 and Ringer’s lactate solutions as support solutions for the synthesis of proteoglycan by the chondrocytes. Glycerol supported the metabolism for the first 2 h, but then showed a leveling off, indicating a suppression of synthesis. HEPES and Dextran 40 showed moderate support initially, but the support failed to rise with advancing time, since there was a suppression of metabolic activity after the first hour. Tris performed very poorly, presumably because of its excessive alkalinity. The pH of Ham’s F-12 solution was the most physiologic. Dextran 40 was exceptionally acidic (4.3) and Tris 0.3 M was exceptionally alkaline (pH 10.2) (Table 1). The other solutions fell into a slightly acidic but still physiologically acceptable range. The conductivity of distilled water was lowest (0.005 mho). The conductivity of glycerol was very low (14.2 mho), while the two physiologic control solutions were most highly conductive (13,400 mho for Ham’s F-12 and 10,620 mho for Ringer’s lactate). The osmolarity of all the solutions except Arthroscopy.
Vol. 7, No. 1, 1991
ET AL.
I
0
A
Lactated Ringer’s
0 l
2.6 O/CGlycerol 0.3 M HEPES
o
0.3M TRIS
I 1
I
I
I
I
I
I
1
2
3
4
5
6
7
0
HOURS FIG. 1. The rates of incorporation of radiosulfate (?S.O,) into bovine articular cartilage slices at various time intervals from an in vitro system. Rate varies for the solutions tested. The “ideal” reference solutions are Ham’s F-12 medium and Ringer’s lactate (both electrolytic). Glycerol 2.6% percent, Dextran 40, and HEPES buffer supported the cartilage reasonably well for the first 2 h of the study. Distilled water (not shown) gave results very similar to 0.3 M Tris.
distilled water fell into the physiologic range. The behavior of the various solutions when coagulation and cutting currents were used are shown; only HEPES worked well with both electrical currents. Glycerol was effective in conducting the cutting current, but did not do as well with electrocoagulation. The other solutions all exhibited either sparking (Ringer’s lactate) or caramelization (Dextran and Tris). DISCUSSION Electrocoagulation is an effective and simple way to control bleeding during surgery. Electrocautery can be used to divide tissues, for example, when performing a lateral retinacular release (3) or meniscectomy (4). Both techniques are probably unsafe in a joint tilled with an electrolytic solution that may conduct the current to other parts of the body and reduce the efficiency of the local electrical action. Although the use of sterile water has been advocated, this fluid is highly unphysiologic. Ultrastruc-
LOW
CONDUCTIVITY
IRRIGATING
TABLE 1. Physiologic conductive and electrocautery Solution
PH
Conductivity (mho)
SOLUTIONS
characteristics
4.30
85.2
325
6.40
14.2
288
0.3 M HEPES
5.50
135.7
307
10.20
202.0
307
Ham’s F-12 Lactated Ringer’s
7.30 6.10
13,400O.o 10,620.O
318 260
Distilled water
7.0
0.005
of test solutions
Osmolarity” (mOsmol/kg)
Dextran-40 (Rheomacrodex) 2.6% glycerol
0.3 M Tris
107
Electrocauterization Cut-caramelization Coag.-poor Cut-good Coag.-poor Cut-good Coag.-good Cut-fair with deposit Coag.-fair -. Cut-marked sparking Coag.-marked sparking Cut-good Coag.-good
0
HEPES (Sigma). N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid; Tris (Sigma), Tris (Hydroxymethyl) Synovial fluid has a pH of 7.0-7.3 and osmolarity of 300 mOsmol/kg. ’ Osmolarity determined by freezing point depression (normal serum, 290-295 mOsmol/kg).
tural damage to surface layers of articular cartilage has been demonstrated following irrigation with water (5). The effect of the amino acid glycine 1.5% on artitular cartilage has been studied (5-7). Adverse effects on cartilage were not demonstrated. However, transient postoperative blindness has been reported as a possible effect of glycine toxicity (8). Glycine is acidic (pH 6.1) and hyposmolar (200m Osmol) (7). Although glycine is used routinely as an irrigating solution for urologic procedures, the bladder is normally exposed to an acidic, hyposmolar environment, joint surfaces are not. Our goal was to find a nonelectrolytic normoosmolar solution that would support articular chondrocyte metabolism and at the same time allow the use of the electrical current. The results of this study demonstrate that two such solutions are available: glycerol 2.6% and HEPES 0.3 M. HEPES is an organic buffer solution commonly used in laboratories for protein and cell experiments. Although neither glycerol nor HEPES solution is optimal in terms of cartilage metabolism, both allow proteoglycan synthesis to continue at a rate at least consistent with that provided by normal saline, particularly if the procedure is not extended beyond 2 h. Both solutions support the electrosurgical system for “cutting”: HEPES did well for “coagulation” but glycerol did not, presumably because the con-
amino methane.
ductivity is so low. Glycerol is slightly more physiologic, inexpensive, and easily sterilized for arthroscopic use. Marshall et al. also found that a glycerol solution was a satisfactory irrigant for arthroscopy (9). While HEPES is slightly better in terms of its nonconductive properties, it is not quite as physiologic. REFERENCES I. Reagan B, McInemey VK, Treadwell BV. et al. Irrigating solutions for arthroscopy. A metabolic study. J Bone Joint Sui-g 1983:65:629-31. 2. Nole R. Munson NML, Fulkerson JP. Bupivacdine and saline effects on articular cartilage. Arthroscopy 1985;l: 123-7. 3. Sherman OH, Fox JM, Sperling H. et al. Patellar instability: Treatment by arthroscopic electrosurgical lateral release. Arthroscopy 1987;3:152-60. 4. Miller CK, Drennan DB, and Maylahn DJ. The effect of technique on histology of arthroscopic partial meniscectomy with electrosurgery. Arthroscopy 1987;3:3W4. 5. Bert JM. Posalaky Z, Snyder S. Effect of various irrigating fluids on the ultrastructure of articular cartilage. Arthroscopy 1990;6: 1041. 6 Bert JM. Use of 1.5% glycine as a nonconductive fluid medium for arthroscopic electrosurgery. Arfhroscopy 1987; 31248-52. 7 Balduini FC, Peff TC, Torg JS. Application of electrothermal energy in arthroscopy. Arthroscopy 1985;1:259-63. 8. Burkhart SS, Barnett CR, Snyder SJ. Transient postoperative blindness as a possible effect of glycine toxicity. Arthroscopy 1990;6: 112-4. 9. Marshall GJ, Kirchen ME, Sweeney JR, et al. Synovisol as an irrigant for electrosurgery of joints. Arthroscopy 1988; 4:187-93.
Arthroscopy.
Vol. 7. No. I. 1991
The Journal
ef Arthroscopic
and Related Surgery 7(l): 105-107
Published by Raven Press. Ltd. 0 1991 Arthroscopy
Low Conductivity
Association of North America
Irrigating Solutions for Arthroscopy
Brian Reagan, M.D., Bertram Zarins, M.D., and Henry J. Mankin, M.D.
Summary: The purpose of this study was to find a nonconductive physiologic solution to use for arthroscopy when electrosurgery is performed. We studied the effect of several solutions on proteoglycan synthesis in bovine articular cartilage slices, and the effect of using an electrosurgical instrument in various solutions in bovine knee joints. Both HEPES buffer 0.3 M (N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid) (Sigma Chemical Company, St. Louis, Missouri) and glycerol 2.6% gave good results in both categories. The glycerol solution appears to be the best from those tested since it supported cartilage metabolism somewhat better and is far less expensive than HEPES solution. Thus, in the use of electrosurgery during arthroscopic procedures, solutions
such as Ringer’s lactate and saline are too conductive to be effective or safe. Distilled water is nonphysiologic. Glycerol 2.6% is safe and effective and supports articular cartilage metabolism reasonably well for up to 2 h. Key Words: Electrosurgery-Irrigating solutions.
M (N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid) (Sigma Chemical Company, St. Louis, Missouri) demonstrated acceptable physiologic properties in relation to articular cartilage and were sufficiently nonconductive to allow use of electrosurgery during the arthroscopic procedure.
we determined that Ringer’s lactate solution was more physiologic than normal saline for arthroscopy (1). Saline has an inhibiting effeet on articular cartilage metabolism (1,2). Ringer’s lactate supported articular cartilage metabolism better than any of the other ionic buffered solutions tested, with the exception of Ham’s F-12 medium as measured by short- and long-term chondrocyte growth in tissue culture. However, Ringer’s lactate and other solutions such as phosphate buffered saline have high conductive properties. A nonconductive solution is more desirable if electrosurgery is used during an arthroscopic procedure. The purpose of this study was to find a non- or minimally conductive irrigating solution that would still support the articular cartilage metabolism. We studied the effects of several nonelectrolytic solutions on proteoglycan synthesis in calf articular cartilage. We found that glycerol 2.6% and HEPES buffer 0.3 In a prior study,
MATERIALS AND METHODS Fresh bovine articular cartilage from an abattoir was sliced, washed, and incubated with modified Ham’s F-12 medium (Gibco) at 37°C for 8 h. The slices were then washed briefly with phosphate buffered saline and placed into screw cap test tubes containing 5.0 ml of the test solution, to which 5 pCi of radiosulfate (specific activity 221 mCilm&f; New England Nuclear) had been added. The slices were incubated at 37°C in duplicate with constant agitation. At the end of each incubation period, cartilage slices were harvested, washed with PBS, and lyophilized, and the dry weight measured using a Mettler Micro Balance. The cartilage slices were then solubilized in formic acid 88% at 6o”C, and, after an overnight digestion, placed into a liquid scintillation fluid (Aquasol 2, New England Nuclear) and counted in a liquid scintillation counter.
From the Orthopaedic Research Laboratories and the Sports Medicine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. Address correspondence and reprint requests to Dr. Bertram Zarins, Massachusetts General Hospital, Ambulatory Care Center, Suite 514, Boston, MA 02114, U.S.A. Presented at the annual meeting of the Arthroscopy Association of North America. San Francisco, March 21, 1986. 105
B. REAGAN
106
The results were recorded as cprn/t_r,gdry weight of tissue. The test solutions for the cartilage incubations were chosen either to serve as controls, as in our prior study (testing Ham’s F-12 medium or Ringer’s lactate) (I), or for their nonelectrolytic and nonconductive natures. The solutions included distilled water, glycerol 2.6%; Tris (hydroxymethyi) amino methane 0.3 M (Sigma); Dextran 40 (Rheomacrodex, Pharmacia); and N-2-hydroxyethylpiperazine iV’-2-ethanesulfonic acid 0.3 M (HEPES; Sigma), a material used in our laboratory for preparation of a cell-free messenger RNA-directed synthetic system. The osmolarity of each of these solutions was tested using freezing point depression, and conductivity was assessed using a conductivity meter. The characteristics of electrosurgery on grounded bovine knee joints were tested using various solutions. We used a Bovie Electrocautery unit, obtained from our operating room, at standard settings for “cutting” and “coagulation.” We placed the electrocautery stylus on the bovine synovial tissues bathed in the fluid and observed the results. We noted the efficiency of the electrosurgical system and the presence of sparking or caramelization of solutions. RESULTS Figure 1 shows the results of the metabolic study and demonstrates the superiority of Ham’s F-12 and Ringer’s lactate solutions as support solutions for the synthesis of proteoglycan by the chondrocytes. Glycerol supported the metabolism for the first 2 h, but then showed a leveling off, indicating a suppression of synthesis. HEPES and Dextran 40 showed moderate support initially, but the support failed to rise with advancing time, since there was a suppression of metabolic activity after the first hour. Tris performed very poorly, presumably because of its excessive alkalinity. The pH of Ham’s F-12 solution was the most physiologic. Dextran 40 was exceptionally acidic (4.3) and Tris 0.3 M was exceptionally alkaline (pH 10.2) (Table 1). The other solutions fell into a slightly acidic but still physiologically acceptable range. The conductivity of distilled water was lowest (0.005 mho). The conductivity of glycerol was very low (14.2 mho), while the two physiologic control solutions were most highly conductive (13,400 mho for Ham’s F-12 and 10,620 mho for Ringer’s lactate). The osmolarity of all the solutions except Arthroscopy.
Vol. 7, No. 1, 1991
ET AL.
I
0
A
Lactated Ringer’s
0 l
2.6 O/CGlycerol 0.3 M HEPES
o
0.3M TRIS
I 1
I
I
I
I
I
I
1
2
3
4
5
6
7
0
HOURS FIG. 1. The rates of incorporation of radiosulfate (?S.O,) into bovine articular cartilage slices at various time intervals from an in vitro system. Rate varies for the solutions tested. The “ideal” reference solutions are Ham’s F-12 medium and Ringer’s lactate (both electrolytic). Glycerol 2.6% percent, Dextran 40, and HEPES buffer supported the cartilage reasonably well for the first 2 h of the study. Distilled water (not shown) gave results very similar to 0.3 M Tris.
distilled water fell into the physiologic range. The behavior of the various solutions when coagulation and cutting currents were used are shown; only HEPES worked well with both electrical currents. Glycerol was effective in conducting the cutting current, but did not do as well with electrocoagulation. The other solutions all exhibited either sparking (Ringer’s lactate) or caramelization (Dextran and Tris). DISCUSSION Electrocoagulation is an effective and simple way to control bleeding during surgery. Electrocautery can be used to divide tissues, for example, when performing a lateral retinacular release (3) or meniscectomy (4). Both techniques are probably unsafe in a joint tilled with an electrolytic solution that may conduct the current to other parts of the body and reduce the efficiency of the local electrical action. Although the use of sterile water has been advocated, this fluid is highly unphysiologic. Ultrastruc-
LOW
CONDUCTIVITY
IRRIGATING
TABLE 1. Physiologic conductive and electrocautery Solution
PH
Conductivity (mho)
SOLUTIONS
characteristics
4.30
85.2
325
6.40
14.2
288
0.3 M HEPES
5.50
135.7
307
10.20
202.0
307
Ham’s F-12 Lactated Ringer’s
7.30 6.10
13,400O.o 10,620.O
318 260
Distilled water
7.0
0.005
of test solutions
Osmolarity” (mOsmol/kg)
Dextran-40 (Rheomacrodex) 2.6% glycerol
0.3 M Tris
107
Electrocauterization Cut-caramelization Coag.-poor Cut-good Coag.-poor Cut-good Coag.-good Cut-fair with deposit Coag.-fair -. Cut-marked sparking Coag.-marked sparking Cut-good Coag.-good
0
HEPES (Sigma). N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid; Tris (Sigma), Tris (Hydroxymethyl) Synovial fluid has a pH of 7.0-7.3 and osmolarity of 300 mOsmol/kg. ’ Osmolarity determined by freezing point depression (normal serum, 290-295 mOsmol/kg).
tural damage to surface layers of articular cartilage has been demonstrated following irrigation with water (5). The effect of the amino acid glycine 1.5% on artitular cartilage has been studied (5-7). Adverse effects on cartilage were not demonstrated. However, transient postoperative blindness has been reported as a possible effect of glycine toxicity (8). Glycine is acidic (pH 6.1) and hyposmolar (200m Osmol) (7). Although glycine is used routinely as an irrigating solution for urologic procedures, the bladder is normally exposed to an acidic, hyposmolar environment, joint surfaces are not. Our goal was to find a nonelectrolytic normoosmolar solution that would support articular chondrocyte metabolism and at the same time allow the use of the electrical current. The results of this study demonstrate that two such solutions are available: glycerol 2.6% and HEPES 0.3 M. HEPES is an organic buffer solution commonly used in laboratories for protein and cell experiments. Although neither glycerol nor HEPES solution is optimal in terms of cartilage metabolism, both allow proteoglycan synthesis to continue at a rate at least consistent with that provided by normal saline, particularly if the procedure is not extended beyond 2 h. Both solutions support the electrosurgical system for “cutting”: HEPES did well for “coagulation” but glycerol did not, presumably because the con-
amino methane.
ductivity is so low. Glycerol is slightly more physiologic, inexpensive, and easily sterilized for arthroscopic use. Marshall et al. also found that a glycerol solution was a satisfactory irrigant for arthroscopy (9). While HEPES is slightly better in terms of its nonconductive properties, it is not quite as physiologic. REFERENCES I. Reagan B, McInemey VK, Treadwell BV. et al. Irrigating solutions for arthroscopy. A metabolic study. J Bone Joint Sui-g 1983:65:629-31. 2. Nole R. Munson NML, Fulkerson JP. Bupivacdine and saline effects on articular cartilage. Arthroscopy 1985;l: 123-7. 3. Sherman OH, Fox JM, Sperling H. et al. Patellar instability: Treatment by arthroscopic electrosurgical lateral release. Arthroscopy 1987;3:152-60. 4. Miller CK, Drennan DB, and Maylahn DJ. The effect of technique on histology of arthroscopic partial meniscectomy with electrosurgery. Arthroscopy 1987;3:3W4. 5. Bert JM. Posalaky Z, Snyder S. Effect of various irrigating fluids on the ultrastructure of articular cartilage. Arthroscopy 1990;6: 1041. 6 Bert JM. Use of 1.5% glycine as a nonconductive fluid medium for arthroscopic electrosurgery. Arfhroscopy 1987; 31248-52. 7 Balduini FC, Peff TC, Torg JS. Application of electrothermal energy in arthroscopy. Arthroscopy 1985;1:259-63. 8. Burkhart SS, Barnett CR, Snyder SJ. Transient postoperative blindness as a possible effect of glycine toxicity. Arthroscopy 1990;6: 112-4. 9. Marshall GJ, Kirchen ME, Sweeney JR, et al. Synovisol as an irrigant for electrosurgery of joints. Arthroscopy 1988; 4:187-93.
Arthroscopy.
Vol. 7. No. I. 1991