- Email: [email protected]
Traction versus distension for distraction of the joint during hip arthroscopy
Traction Versus Distension for Distraction of the Joint During Hip Arthroscopy J. W. Thomas Byrd, M.D., and Kenneth Y. Chern, M.D.
Summary: Distraction is the most popular technique used in hip arthroscopy. It has been postulated that, if adequate distraction cannot initially be achieved with traction, it will be overcome by distension. The purpose of this study is to quantitate the additive effects of traction and distension in achieving distraction of the hip joint for arthroscopy. Eleven consecutive patients undergoing hip arthroscopy in the supine position on a fracture table were studied. Radiographs of the hip were obtained before and immediately after applying 50 pounds of traction. The hip was then immediately distended with 40 mL saline, and a third radiograph was obtained. After correcting for magnification, distraction was measured for traction alone (DT) and traction plus distension (Dvo). A paired t-test was used to compare DT and DTD. Additionally, the ratio of distraction attributed to distension was compared with distraction attributed to traction ([DTD -- DT]/DT) and was defined as the delta percent (A%). Adequate distraction for arthroscopy was able to be achieved in all cases. Distraction due to traction alone (Dv) ranged from 2.8 mm to 10.3 ram, with an average of 6.2 mm. Distraction due to traction plus distension (DTD) ranged from 4.8 mm to 10.3 mm, with an average of 7.2 mm. The difference between DT and DTD was statistically significant (P < .05). The change in distraction due to distension (A%) ranged from 0% to 81% with an average of 22%. This study shows that distension may facilitate distraction but the degree is variable. Key Words: Hip arthroscopy--Technique--Traction--Distension.
he first recorded attempt at arthroscopic visualization of the hip is attributed to Burman ~ in 1931. He examined the interior of more than 90 various cadaveric joints, including 20 hips. The first clinical application of hip arthroscopy was reported by Takagi 2 in 1939. His report contained four hips, including two Charcot joints, one tuberculous arthritis, and one suppurative arthritis. After Takagi's report, the clinical applications of hip arthroscopy went unmentioned until the late 1970s,
T
From the Southern Sports Medicine and Orthopaedic Center and the Department of Orthopaedics and Rehabilitation, Vanderbilt University School of Medicine, Nashville, Tennessee (J.W.T.B.); and Central Indiana Sports Medicine, Anderson, Indiana (K. Y.C.), U.S.A. Address correspondence and reprint requests to J. W. Thomas Byrd, M.D., Southern Sports Medicine and Orthopaedic Center, 2021 Church St, Second Floor, Nashville, TN 37203, U.S.A. © 1997 by the Arthroscopy Association of North America 0749-8063/97/1303-150553.00/0
346
when two series were reported on the use of arthroscopy in children, first by Gross 3 and, subsequently, Holgersson et al. 4 In 1986, Eriksson et al. 5 described the forces necessary for adequate hip distraction for arthroscopy. In the same year, Johnson 6 described the technique in his textbook Diagnostic and Surgical Arthroscopy. In 1987, Glick et al. 7 reported on their technique of hip arthroscopy and, subsequently, the clinical applications began to flourish. By the early 1990s, hip arthroscopy has become a well-established procedure, with a variety of reported indications. Although there have been a number of variations in the methods of technical application of hip arthroscopy, most authors advocate the use of distraction. There have been only two reports in the literature describing hip arthroscopy without distraction. 8'9 Distraction is thus an important process in the course of hip arthroscopy. Distraction of the hip is facilitated by both traction applied to the extremity and distension
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 13, No 3 (June), 1997: pp 346-349
TRACTION VERSUS DISTENSION TABLE 1. Summary of Results R/L
Age (yr)
Sex
DX
DT
DTD
A%
L L R L L L R R L R R
57 17 52 39 46 34 50 31 20 45 64
M F F F M F M F M F F
OA LL SD LL AVN LL AVN SD CD LL OA
6.5 6.6 7.0 5.2 6.1 3.7 2.8 10.3 4.7 5.5 10.3
6.5 6.6 8.0 5.2 7.2 4.8 5.1 10.3 8.1 6.8 10.3
0 0 14.2 0 17.8 30.7 80.7 0 72.8 24.5 0
Abbreviations: R, right; L, left; M, male; F, female; OA, osteoarthritis; LL, labral lesion; SD, synovial disease; AVN, avascular necrosis; CD, chondral damage.
of the joint with fluid. Consequently, the author believed that it would be important to try to quantitate the contributions of both.
MATERIALS AND METHODS Eleven consecutive patients undergoing hip arthroscopy for a variety of diagnoses were studied (Table 1). The technique of hip arthroscopy was performed as previously described by the author. 1°-12 The procedure was performed on a Skytron fracture
FIG 1. The C-arm is positioned between the legs, providing a PA image of the operative hip with the image intensifier positioned at a fixed distance above the operating table.
347
table with a transducer built into the foot plate to quantitate the amount of traction force applied. Images were obtained using a Phillips BV25 C-arm with the image intensifier positioned at a standard distance of 45 cm above the operating table (Fig 1). Three radiographs of the hip were obtained: (1) before applying traction; (2) immediately after applying 50 pounds of traction; and (3) after distending the joint with 40 m L fluid. Distension was performed via an 18-gauge 6-inch spinal needle immediately after applying the traction. Subsequent radiographs were performed when the cannula had been introduced into the hip joint. These cannulas were of known dimensions (5.2 m m outer diameter [OD]) and used in calculating magnification of the images. For measurement purposes on the radiographs, an index point was chosen in the superior weight-bearing portion o f the acetabulum that was identifiable on all three radiographs. The second point was chosen, corresponding to the subchondral bone of the femoral head immediately distal (caudad) to the point chosen in the acetabulum (Fig 2). Measurements were then made using a caliper (Fowler Ultra-Cal Mark III, accurate to 0.03 mm) and 3.5× loupe magnification. Measurements were made serially on all radiographs and then repeated two more times to determine a standard error.
348
J. W.T. BYRD AND K. E CHERN distension (DTD) ranged from 4.8 m m to 10.3 ram, with an average of 7.2 _+ 0.6 (SE) mm. The difference between DT and DaD was statistically significant (P > .05). The change in distraction due to distension (A%) ranged from 0% to 81%, with an average of 22%.
|
DISCUSSION
Ill
FIG 2. An index point is selected for each case in the superior portion of the acetabulum, which is identifiable on all three radiographs. The second point is selected corresponding to the subchondral bone of the femoral head, immediately caudad to the index point.
When the distraction technique for hip arthroscopy is used, both traction and distension are integral to adequate distraction necessary for the procedure. Distraction due to traction may be facilitated through the process of physiological creep, whereby the capsule gradually accommodates to the tensile stresses placed on it, relaxing and allowing distraction with less traction force over time. This influence was eliminated by obtaining radiographs immediately after applying 50 pounds of traction and then immediately distending the joint with 40 mL saline and obtaining the final radiograph. Thus, time has not allowed for accommodation of the soft tissues because of physiological creep. The distension effect is a combination of eliminating the negative effect created by the vacuum phenomenon (Fig 3) combined with the positive intracapsular pressure created by instillation of fluid. Both of these are accounted for in the distension effect recorded here. Villar ~3 has reported that, as long as at least 1 m m of distraction can be achieved with 25 kg traction, this is adequate, and subsequent distraction can be achieved
Subtracting the distance when no traction was applied, measurements were recorded for traction alone (DT) and traction plus distension (DAD). A paired ttest was used to compare DT and DaD. Additionally, the ratio of distraction attributed to distension was compared with distraction attributed to traction ([DAD - DT]/DT) and was defined as the Delta percent (A%). RESULTS
Adequate distraction for arthroscopy was able to be achieved in all cases. After correcting for magnification (111%), distraction due to traction alone (DT) ranged from 2.8 m m to 10.3 mm, with an average of 6.2 -4- 0.7 (SE) mm. Distraction due to traction plus
FIG 3. The vacuum phenomenon is shown on this radiographic image. It is created by the negative intracapsular pressure developed by distraction of the joint. It is characterized by the distinct radiolucency (arrow) evident between the joint surfaces.
TRACTION VERSUS DISTENSION with distension. However, this effect has not previously been quantitated. Adequate distraction for arthroscopy necessitates that the joint surfaces be separated sufficiently to introduce the instrumentation within the joint. The values of distraction recorded here are pertinent only in the relationship of the value attributable to distraction compared with the combined value of traction and distension. The absolute values of distraction did not necessarily reflect the total amount of clinical distraction achieved. The reference points on the acetabulum and femoral head were chosen because of their reproducibility and visualization on the radiographs. They represent two points on a two-dimensional image of a three-dimensional structure. These two points may not be in the same plane and thus do not necessarily reflect the total amount of separation of the articular surfaces. An alternative study of interest would be to distend the joint with fluid and see if any measurable distraction occurs before the application of traction. However, in his clinical setting, the author has preferred to distract the hip before introduction of the 18-gauge spinal needle used for distending the joint and consequently has not pursued this investigative technique. Rotation of the joint might affect capsular tension and distension. This variable was eliminated by performing each procedure with the hip maintained in neutral rotation. Quantitating the effect of rotation might provide useful information but is not addressed in this work. It should be noted that many anterior soft tissue lesions may be readily approached by arthroscopy without distraction, as advocated by several authors. 8'9 This article does not address the merits of traction versus nontraction techniques, but the diverse theories regarding these two approaches are important in considering the clinical applications of hip arthroscopy.
349
Hip arthroscopy is most frequently performed using the technique of distraction to facilitate introduction of instruments into the joint. Distraction is achieved through a combination of traction applied to the extremity and distension of the capsule with fluid. The results of this small population show that distension may facilitate distraction, but the degree is variable. A larger series of patients will further quantitate this effect, especially selecting a homogenous population based on a single pathological condition. Until this effect is better defined, it is the senior author's opinion that distension should not always be counted on to overcome inadequate traction for hip arthroscopy.
REFERENCES 1. Burman MS. Arthroscopy or the direct visualization of joints. J Bone Joint Surg 1931; 13:669-694. 2. Takagi K. The arthroscope: The second report. J Jpn Orthop Assoc 1939B; 14:441-466. 3. Gross RH. Arthroscopy in hip disorders in children. Orthop Rev 1977; 6:43-49. 4. Holgersson S, Brattstrtim H, Mogensen B, Lidgren L. Arthroscopy of the hip in juvenile chronic arthritis. J Pediatr Orthop 1981; 1:273-278. 5. Eriksson E, Arvidsson I, Arvidsson H. Diagnostic and operative arthroscopy of the hip. Orthopaedics 1986;9:169-176. 6. Johnson L. Hip joint. In: Johnson L, ed. Diagnostic and Surgical Arthroscopy. Ed 3. St. Louis: Mosby, 1986;1491-1519. 7. Glick JM, Sampson TG, Gordon RB, Behr JT, Schmidt E. Hip arthroscopy by the lateral approach. Arthroscopy 1987;3:4-12. 8. Dorfmann H, Boyer T, Henry P, De Bie B. A simple approach to hip arthroscopy. Arthroscopy 1988;4:141-142. 9. Klapper RC, Silver DM. Hip arthroscopy without traction. Contemp Orthop 1989; 18:687-693. 10. Byrd JWT. Hip arthroscopy utilizing the supine position. Arthroscopy 1994; 10:275-280. 11. Byrd JWT. Arthroscopic Surgery of the Hip. IOI Theater [Videotape], AAOS Annual Meeting, Orlando, FL, February 1995. 12. Byrd JWT. Hip arthroscopy: The supine position. In: McGinty J, Caspari R, Jackson R, Poehling G, eds. Operative Arthroscopy. Ed 2. New York: Raven Press, 1996. 13. Villar RN. The technique of hip arthroscopy. In: Villar RN, ed. Hip Arthroscopy. Oxford: Butterworth-Heinemann, 1992:39-53.
Summary: Distraction is the most popular technique used in hip arthroscopy. It has been postulated that, if adequate distraction cannot initially be achieved with traction, it will be overcome by distension. The purpose of this study is to quantitate the additive effects of traction and distension in achieving distraction of the hip joint for arthroscopy. Eleven consecutive patients undergoing hip arthroscopy in the supine position on a fracture table were studied. Radiographs of the hip were obtained before and immediately after applying 50 pounds of traction. The hip was then immediately distended with 40 mL saline, and a third radiograph was obtained. After correcting for magnification, distraction was measured for traction alone (DT) and traction plus distension (Dvo). A paired t-test was used to compare DT and DTD. Additionally, the ratio of distraction attributed to distension was compared with distraction attributed to traction ([DTD -- DT]/DT) and was defined as the delta percent (A%). Adequate distraction for arthroscopy was able to be achieved in all cases. Distraction due to traction alone (Dv) ranged from 2.8 mm to 10.3 ram, with an average of 6.2 mm. Distraction due to traction plus distension (DTD) ranged from 4.8 mm to 10.3 mm, with an average of 7.2 mm. The difference between DT and DTD was statistically significant (P < .05). The change in distraction due to distension (A%) ranged from 0% to 81% with an average of 22%. This study shows that distension may facilitate distraction but the degree is variable. Key Words: Hip arthroscopy--Technique--Traction--Distension.
he first recorded attempt at arthroscopic visualization of the hip is attributed to Burman ~ in 1931. He examined the interior of more than 90 various cadaveric joints, including 20 hips. The first clinical application of hip arthroscopy was reported by Takagi 2 in 1939. His report contained four hips, including two Charcot joints, one tuberculous arthritis, and one suppurative arthritis. After Takagi's report, the clinical applications of hip arthroscopy went unmentioned until the late 1970s,
T
From the Southern Sports Medicine and Orthopaedic Center and the Department of Orthopaedics and Rehabilitation, Vanderbilt University School of Medicine, Nashville, Tennessee (J.W.T.B.); and Central Indiana Sports Medicine, Anderson, Indiana (K. Y.C.), U.S.A. Address correspondence and reprint requests to J. W. Thomas Byrd, M.D., Southern Sports Medicine and Orthopaedic Center, 2021 Church St, Second Floor, Nashville, TN 37203, U.S.A. © 1997 by the Arthroscopy Association of North America 0749-8063/97/1303-150553.00/0
346
when two series were reported on the use of arthroscopy in children, first by Gross 3 and, subsequently, Holgersson et al. 4 In 1986, Eriksson et al. 5 described the forces necessary for adequate hip distraction for arthroscopy. In the same year, Johnson 6 described the technique in his textbook Diagnostic and Surgical Arthroscopy. In 1987, Glick et al. 7 reported on their technique of hip arthroscopy and, subsequently, the clinical applications began to flourish. By the early 1990s, hip arthroscopy has become a well-established procedure, with a variety of reported indications. Although there have been a number of variations in the methods of technical application of hip arthroscopy, most authors advocate the use of distraction. There have been only two reports in the literature describing hip arthroscopy without distraction. 8'9 Distraction is thus an important process in the course of hip arthroscopy. Distraction of the hip is facilitated by both traction applied to the extremity and distension
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 13, No 3 (June), 1997: pp 346-349
TRACTION VERSUS DISTENSION TABLE 1. Summary of Results R/L
Age (yr)
Sex
DX
DT
DTD
A%
L L R L L L R R L R R
57 17 52 39 46 34 50 31 20 45 64
M F F F M F M F M F F
OA LL SD LL AVN LL AVN SD CD LL OA
6.5 6.6 7.0 5.2 6.1 3.7 2.8 10.3 4.7 5.5 10.3
6.5 6.6 8.0 5.2 7.2 4.8 5.1 10.3 8.1 6.8 10.3
0 0 14.2 0 17.8 30.7 80.7 0 72.8 24.5 0
Abbreviations: R, right; L, left; M, male; F, female; OA, osteoarthritis; LL, labral lesion; SD, synovial disease; AVN, avascular necrosis; CD, chondral damage.
of the joint with fluid. Consequently, the author believed that it would be important to try to quantitate the contributions of both.
MATERIALS AND METHODS Eleven consecutive patients undergoing hip arthroscopy for a variety of diagnoses were studied (Table 1). The technique of hip arthroscopy was performed as previously described by the author. 1°-12 The procedure was performed on a Skytron fracture
FIG 1. The C-arm is positioned between the legs, providing a PA image of the operative hip with the image intensifier positioned at a fixed distance above the operating table.
347
table with a transducer built into the foot plate to quantitate the amount of traction force applied. Images were obtained using a Phillips BV25 C-arm with the image intensifier positioned at a standard distance of 45 cm above the operating table (Fig 1). Three radiographs of the hip were obtained: (1) before applying traction; (2) immediately after applying 50 pounds of traction; and (3) after distending the joint with 40 m L fluid. Distension was performed via an 18-gauge 6-inch spinal needle immediately after applying the traction. Subsequent radiographs were performed when the cannula had been introduced into the hip joint. These cannulas were of known dimensions (5.2 m m outer diameter [OD]) and used in calculating magnification of the images. For measurement purposes on the radiographs, an index point was chosen in the superior weight-bearing portion o f the acetabulum that was identifiable on all three radiographs. The second point was chosen, corresponding to the subchondral bone of the femoral head immediately distal (caudad) to the point chosen in the acetabulum (Fig 2). Measurements were then made using a caliper (Fowler Ultra-Cal Mark III, accurate to 0.03 mm) and 3.5× loupe magnification. Measurements were made serially on all radiographs and then repeated two more times to determine a standard error.
348
J. W.T. BYRD AND K. E CHERN distension (DTD) ranged from 4.8 m m to 10.3 ram, with an average of 7.2 _+ 0.6 (SE) mm. The difference between DT and DaD was statistically significant (P > .05). The change in distraction due to distension (A%) ranged from 0% to 81%, with an average of 22%.
|
DISCUSSION
Ill
FIG 2. An index point is selected for each case in the superior portion of the acetabulum, which is identifiable on all three radiographs. The second point is selected corresponding to the subchondral bone of the femoral head, immediately caudad to the index point.
When the distraction technique for hip arthroscopy is used, both traction and distension are integral to adequate distraction necessary for the procedure. Distraction due to traction may be facilitated through the process of physiological creep, whereby the capsule gradually accommodates to the tensile stresses placed on it, relaxing and allowing distraction with less traction force over time. This influence was eliminated by obtaining radiographs immediately after applying 50 pounds of traction and then immediately distending the joint with 40 mL saline and obtaining the final radiograph. Thus, time has not allowed for accommodation of the soft tissues because of physiological creep. The distension effect is a combination of eliminating the negative effect created by the vacuum phenomenon (Fig 3) combined with the positive intracapsular pressure created by instillation of fluid. Both of these are accounted for in the distension effect recorded here. Villar ~3 has reported that, as long as at least 1 m m of distraction can be achieved with 25 kg traction, this is adequate, and subsequent distraction can be achieved
Subtracting the distance when no traction was applied, measurements were recorded for traction alone (DT) and traction plus distension (DAD). A paired ttest was used to compare DT and DaD. Additionally, the ratio of distraction attributed to distension was compared with distraction attributed to traction ([DAD - DT]/DT) and was defined as the Delta percent (A%). RESULTS
Adequate distraction for arthroscopy was able to be achieved in all cases. After correcting for magnification (111%), distraction due to traction alone (DT) ranged from 2.8 m m to 10.3 mm, with an average of 6.2 -4- 0.7 (SE) mm. Distraction due to traction plus
FIG 3. The vacuum phenomenon is shown on this radiographic image. It is created by the negative intracapsular pressure developed by distraction of the joint. It is characterized by the distinct radiolucency (arrow) evident between the joint surfaces.
TRACTION VERSUS DISTENSION with distension. However, this effect has not previously been quantitated. Adequate distraction for arthroscopy necessitates that the joint surfaces be separated sufficiently to introduce the instrumentation within the joint. The values of distraction recorded here are pertinent only in the relationship of the value attributable to distraction compared with the combined value of traction and distension. The absolute values of distraction did not necessarily reflect the total amount of clinical distraction achieved. The reference points on the acetabulum and femoral head were chosen because of their reproducibility and visualization on the radiographs. They represent two points on a two-dimensional image of a three-dimensional structure. These two points may not be in the same plane and thus do not necessarily reflect the total amount of separation of the articular surfaces. An alternative study of interest would be to distend the joint with fluid and see if any measurable distraction occurs before the application of traction. However, in his clinical setting, the author has preferred to distract the hip before introduction of the 18-gauge spinal needle used for distending the joint and consequently has not pursued this investigative technique. Rotation of the joint might affect capsular tension and distension. This variable was eliminated by performing each procedure with the hip maintained in neutral rotation. Quantitating the effect of rotation might provide useful information but is not addressed in this work. It should be noted that many anterior soft tissue lesions may be readily approached by arthroscopy without distraction, as advocated by several authors. 8'9 This article does not address the merits of traction versus nontraction techniques, but the diverse theories regarding these two approaches are important in considering the clinical applications of hip arthroscopy.
349
Hip arthroscopy is most frequently performed using the technique of distraction to facilitate introduction of instruments into the joint. Distraction is achieved through a combination of traction applied to the extremity and distension of the capsule with fluid. The results of this small population show that distension may facilitate distraction, but the degree is variable. A larger series of patients will further quantitate this effect, especially selecting a homogenous population based on a single pathological condition. Until this effect is better defined, it is the senior author's opinion that distension should not always be counted on to overcome inadequate traction for hip arthroscopy.
REFERENCES 1. Burman MS. Arthroscopy or the direct visualization of joints. J Bone Joint Surg 1931; 13:669-694. 2. Takagi K. The arthroscope: The second report. J Jpn Orthop Assoc 1939B; 14:441-466. 3. Gross RH. Arthroscopy in hip disorders in children. Orthop Rev 1977; 6:43-49. 4. Holgersson S, Brattstrtim H, Mogensen B, Lidgren L. Arthroscopy of the hip in juvenile chronic arthritis. J Pediatr Orthop 1981; 1:273-278. 5. Eriksson E, Arvidsson I, Arvidsson H. Diagnostic and operative arthroscopy of the hip. Orthopaedics 1986;9:169-176. 6. Johnson L. Hip joint. In: Johnson L, ed. Diagnostic and Surgical Arthroscopy. Ed 3. St. Louis: Mosby, 1986;1491-1519. 7. Glick JM, Sampson TG, Gordon RB, Behr JT, Schmidt E. Hip arthroscopy by the lateral approach. Arthroscopy 1987;3:4-12. 8. Dorfmann H, Boyer T, Henry P, De Bie B. A simple approach to hip arthroscopy. Arthroscopy 1988;4:141-142. 9. Klapper RC, Silver DM. Hip arthroscopy without traction. Contemp Orthop 1989; 18:687-693. 10. Byrd JWT. Hip arthroscopy utilizing the supine position. Arthroscopy 1994; 10:275-280. 11. Byrd JWT. Arthroscopic Surgery of the Hip. IOI Theater [Videotape], AAOS Annual Meeting, Orlando, FL, February 1995. 12. Byrd JWT. Hip arthroscopy: The supine position. In: McGinty J, Caspari R, Jackson R, Poehling G, eds. Operative Arthroscopy. Ed 2. New York: Raven Press, 1996. 13. Villar RN. The technique of hip arthroscopy. In: Villar RN, ed. Hip Arthroscopy. Oxford: Butterworth-Heinemann, 1992:39-53.