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The role of arthroscopic debridement after anterior cruciate ligament reconstruction
Arthroscopy: The Journal of Arthroscopic and Related Surgery 7(4):34&349 Published
by
Raven Press, Ltd. 0
1991
Arthroscopy Association of North America
The Role of Arthroscopic Debridement After Anterior Cruciate Ligament Reconstruction W. Dilworth Cannon, Jr., M.D., and Joyce M. Vittori, B.A.
Summary: This retrospective study included 55 patients who had prior anterior cruciate ligament (ACL) reconstruction; 30 made up the experimental group who had arthroscopic debridement of impinging soft tissue and 25, who did not have a second-look arthroscopy, were used as controls. Impinging tissue was
not necessarily the primary reason for arthroscopy in the experimental group. Only nine patients (30%) were debrided solely because of anterior symptoms suggestive of soft tissue impingement; 16 (53%) underwent arthroscopy primarily to assess meniscal repairs; five (17%) were done in conjunction with hardware removal. Both groups were evaluated for pain, crepitation, and anterior laxity at three specific times. Debridement reduced crepitation from 35% to 8% in patients with moderate crepitus, and from 50% to 38% in patients with mild symptoms. The percentage of patients without crepitation increased from 15% to 54% by final follow-up. Predebridement, 14% of patients had moderate pain, and 53% mild pain. By final follow-up, 38% had mild pain and 62% were pain free. Patients benefitted from debridement regardless of method of ACL reconstruction. Arthroscopic debridement did not increase anterior knee translation. Both groups gained extension and had improved activity levels with the passage of time from ACL surgery. Key Words: Debridement-Anterior cru-
ciate ligament reconstruction.
These observations were not unanticipated; the risks of such postoperative extensor mechanism problems as chondromalacia patella or degenerative joint disease after ACL reconstruction have long been recognized (4-9). Nevertheless, after resection and debridement of impinging tissue (Fig. 2), most patients were improved. This retrospective study was initiated to discern if arthroscopic debridement proved to be significantly beneficial in patients who had prior ACL reconstruction and symptoms of soft tissue impingement.
A second-look arthroscopy is an accurate and accepted means of assessing the healing status of arthroscopic meniscal repair (l-3). It was while evaluating patients arthroscopically who had anterior cruciate ligament (ACL) reconstruction in conjunction with meniscal repair that it was observed that a number of grafts had developed excessive fibrous or fibrocartilaginous scar tissue or both anteriorly in the intercondylar notch, the base of the ACL graft, or the fat pad region (Fig. 1). In addition, this soft tissue was frequently found to be impinging anteriorly in the joint during the last 10” of extension.
MATERIALS AND METHODS From the Department of Orthopaedic Surgery, Davies Medical Center, San Francisco, and The Department of Orthopaedic Surgery, University of California, San Francisco, California, U.S.A. Address correspondence and reprint requests to W. Dilworth Cannon, Jr., M.D., University of California, San Francisco, Department of Orthopaedic Surgery, 533 Pamassus Ave., Room U-158, San Francisco, CA 94143-0728, U.S.A. The technique descirbed in this article will be demonstrated in a forthcoming Video Supplement to Arthroscopy.
Of all the ACL reconstructions performed by the senior author between November 1982 and January 1988,55 patients met the criteria for inclusion in this study. These patients were divided into two groups: (a) the experimental group comprising 30 patients who had a second-look arthroscopic debridement at 344
ARTHROSCOPIC
DEBRIDEMENT
FIG. 1. Typical appearance of impinging fibrous scar tissue around the ACL graft, left knee.
least 6 months after ACL reconstruction, and (b) the control group comprised of 25 patients who did not have a second-look surgery after ACL reconstruction. In order to ensure that the control group and the experimental group approximated each other relative to time of surgery, the control group was assembled by taking in chronological order the next patient that met the study criteria. Those ex-
AFTER ACL RECONSTRUCTION
345
eluded from the study were patients that were not treated at Davies Medical Center or who were lost to follow-up examination. Also, because most of the second-look arthroscopies were performed after January 1984, this limited the number of controls selected by eliminating otherwise qualified patients treated before this date. Although all 30 patients in the experimental group had arthroscopic debridement of impinging soft tissue, this may not have been the initial or primary motive for the second-look surgery. In fact, only nine patients (30%) were debrided solely because of anterior pain or crepitation or both suggestive of soft tissue impingement (Fig. 3). Impinging scar tissue was the secondary reason for the arthroscopic debridement of the remaining 21 patients. Secondlook arthroscopy was performed in 16 of these patients (53%) primarily to assess the results of meniscal repair and in five patients (17%) whose chief complaint was hardware pain (Fig. 3). Overall, impinging soft tissue resulted in crepitation during terminal knee extension in 26 patients (87%), pain in 21 patients (70%), and both in 20 patients (67%) before debridement. Crepitation as addressed in this study refers only to anterior crepitation. Patello-femoral crepitation was not a subject of this investigation. The factors analyzed in this study were crepitation during terminal extension, pain, activity level, knee extension, and knee laxity. The evaluation of anterior knee translation was important in determining if debriding the intercondylar notch and around the anterior cruciate graft compromised the
HARDWARE PAI 17%
MENISCUS REPAIR 53% FIG. 2. Same patient after arthroscopic
debridement.
FIG. 3. Reason for second look. The patient breakdown in the experimental group. STI, soft tissue impingement; meniscus repair, second look for assessment of healing. Arthroscopy,
Vol. 7. No. 4. 1991
W. D. CANNON,
346
JR. AND J. M. VITTORI
blood supply or damaged the ACL graft, resulting in its elongation. Crepitation and pain were graded as none, mild, or moderately severe. Activity level was evaluated by whether the patient was able to return to a preinjury level of sports, to a lower level of participation or different sports, or only to activities of daily living. Anterior knee translation was measured with the Knee Laxity Tester (Orthopedic Systems Inc., Hayward, CA, U.S.A.) using 20- and 40-pound anterior forces at 25-30” of knee flexion.
EXPERIMENTAL
CONTROL GROUP
GROUP
26PTS
17PTS
26PTS
PRE
POST
FINAL
PTS
0 PTS
19 PTS
901 %
SOY 702
1
60X
T
50%
:
40%
N i
30x 2on 101 0%
RESULTS The average time from ACL reconstruction to final follow-up examination in the experimental group was 27 months (range g-60) and 23 months (range 7-52) in the control group. Patients in the experimental group had arthroscopic debridement anytime from 6 to 36 months after ACL reconstruction. The factors of crepitation, pain, knee extension, and anterior knee translation evaluated in this study could have been affected either adversely or favorably by time. Activity level was most certainly affected by time because all patients were put on a protocol restricting their activities for a full year after ACL reconstructive surgery. Therefore, in addition to an overall analysis of the data, the results of the experimental and control groups were evaluated at three specific times in order to monitor and evaluate any changes. Patients in the experimental group were examined before arthroscopy, at approximately 2 months postarthroscopic debridement, and at final follow-up examination. The average time of second-look arthroscopy in patients debrided less than 1 year after ACL surgery was 7 months. The average interval to arthroscopic debridement in patients more than 12 months after ACL reconstruction was 16 months. Accordingly, patients in the control group were evaluated at 7 and 16 months after ACL reconstruction and again at final follow-up examination. Of the 30 patients in the experimental group, 26 were followed out to final follow-up examination. The four patients not included in this aspect of the study had arthroscopy less than 2 months before final follow-up examination. Crepitation The experimental group (Fig. 4) showed a steady reduction of moderate crepitation from 35% predebridement to 18% postdebridement, and to 8% by Arthroscopy,
Vol. 7, No. 4, 1991
m
MODERATE
7 MOS m
MILD
16 MOS
0
FINAL
NONE
FIG. 4. Overall effect of arthroscopic debridement on crepitation as compared with the control group over time.
final examination. The overall reduction of moderate crepitation was statistically significant at p < .Ol.The percentage of patients without crepitus increased from 15% predebridement to 29% postdebridement and climbed to 54% by final follow-up examination (p < .Ol). In contrast, the incidence of crepitation was low in the control group and remained virtually unchanged throughout the course of the study (Fig. 4). In the experimental group, the 12 patients who had a modified Mott ACL reconstruction using doubled semitendinosus tendon were compared with the 14 patients who had reconstruction using the middle third patellar tendon (Fig. 5). The middle third patellar tendon group fared less well, with 43% of the group experiencing moderate crepitus, 50% having mild symptoms, and only 7% having no crepitation before arthroscopic debridement. Although the modified Mott group initially had only a 25% incidence of moderate crepitation, by final folMODIFIED
MOTT
MID
3RD
PAT TENDON
100%
90x %
80% 70%
1
60%
T
5on
:
4on
v s
30% 20%
0% PRE-SCOPE =
PRE-SCOPE
FINAL MODERATE
FIG. 5. Effect of arthroscopic type of ACL reconstruction.
m
MILD
debridement
0
FINAL
NONE
on crepitation
by
ARTHROSCOPIC
DEBRIDEMENT
AFTER ACL RECONSTRUCTION
low-up examination the middle third patellar tendon and the modified Mott groups had comparably good results, with moderate crepitation occurring in only 7% and 8%, respectively (Fig. 5).
Activity level There were 25 patients in the experimental and 21 patients in the control group who were more than 1 year post-ACL reconstruction and therefore no longer restricted by the dictates of their rehabilitation protocol. These patients were evaluated with regards to activity level. The findings showed that there was no statistical difference in improvement (p > .05) in activity level after arthroscopic debridement compared with the control group. A return to
/ 11
EXPERIMENTAL roou,
26 PTS m
17 PTS
GROUP
50%
%
65%
70% 1
60%
T
50%
:
40%
7 s
CONTROL 19 PTS
26 PT.9
30% 20%
GROUP
8 PTS
19 PTS
79%
PRE
POST -MODERATE
FINAL
PRE-SCOPE
FINAL
MID 3RD PAT TENDON
60th
T
50%
:
40% 30%
Y s
2on 10% 0%
=
MODERATE
FIG. 7. Effect of arthroscopic
PRE-SCOPE m
MILD
0
debridement
FINAL
NONE
on pain by type of
ACL reconstruction.
a preinjury level of activity was accomplished in nine patients (43%) in the control group and nine (36%) in the experimental group. Ten patients in the control group (48%) and 12 in the experimental group (48%) became involved in different activities or a lower level of sports. Patients who limited themselves to activities of daily living were two (9%) in the control and four (16%) in the experimental populations. Knee extension There was an improvement in knee extension among the patients in the experimental group from prearthroscopic debridement to final follow-up. Predebridement figures on 27 patients show three patients (11%) with a more than lo” flexion contracture, seven patients (26%) with a 5-10” contracture, five patients (19%) with a l-4” contracture, and 12 patients (44%) with full extension. At the time of final follow-up examination, no patients had more than a lo” flexion contracture, four patients (15%) had a 5-10” lack of extension, five patients (19%) had a 1-4” contracture, and 18 patients (66%) had achieved full extension. Because the control group had similar improvement, there was no statistical difference (p > .05) between the two groups.
.:1 16% ,\\\ 5%
0%
MOTT
70’1, 1
Pain The overall decrease of pain in patients in the experimental group was statistically significant at p < .Ol. There was a dramatic decrease in pain from 19% with moderate, and 50% with mild pain before debridement, to 0% with moderate, 35% with mild, and 65% pain free by final follow-up examination (Fig. 6). The control group had little variation in pain incidence over time. At 7 months follow-up there was a 5% incidence of moderate pain but by 16 months after ACL reconstruction, there were no further complaints of moderate pain (Fig. 6). Both modified Mott and middle third patellar tendon reconstructed patients had a similar incidence of symptoms of pain before arthroscopic debridement (Fig. 7). By final follow-up, however, the middle third patellar tendon group had a reduction of mild symptoms from 57% to 29%. The complaints of moderate pain had been eliminated in both groups.
MODIFIED
347
16 MOS
&8
MILD
0
FINAL
NONE
FIG. 6. Overall effect of arthroscopic debridement compared with the control group over time.
on pain as
Knee laxity Knee laxity testing was used to measure the involved minus uninvolved anterior translation difference in millimeters between the experimental and control groups at final follow-up examination. Patients were tested with both a 20- and 40-pound anterior force in the Lachman position. Figure 8 shows the mean translation differences between the two groups. The involved minus uninvolved difference of approximately 1 mm in both groups demonArthroscopy.
Vol. 7 No. 4. 1991
348
W. D. CANNON, 1.5,
20
LBS FORCE
JR. AND J. M. VITTORI
40 LBS FORCE
”
EXPERIYENT*L
EXP.
27; CONTROL
CONTROL
EXPERIMENTAL
CONTROL
- 20
FIG. 8. Mean laxitv difference after debridement as measured with an instrumentkd knee laxity tester with a 20- and 40-pound anterior force at final follow-up. (Experimental group: n = 27; control group: n = 20.)
strated the excellent stability of the knees tested. This was an important finding, because it illustrates objectively that there was no change in knee instability in the experimental group and that judicious debridement can be done in the intercondylar notch and around the anterior cruciate graft without jeopardizing knee stability. CASE REPORTS Case 1 A 49-year-old man was treated by second-look arthroscopy for severe soft tissue impingement syndrome 13 months after left knee ACL reconstruction with doubled semitendinosus after an ACL tear and an intercondylar eminence fracture. Arthroscopic examination showed an inordinate amount of fibrocartilaginous tissue in the front of the intercondylar notch that extended across the medial compartment to the midportion of the medial meniscus. The patient had been weight-bearing on a 4to 5-mm thick wafer of fibrocartilaginous tissue. Conventional power-driven debriders failed to remove this tissue. Instead, basket rongeurs were used to piecemeal resect it. Because it was difficult to define the outline of the ACL graft, it was necessary to painstakingly debride around the periphery of the lesion, carefully working into the intercondylar notch. Because there was some impingement during extension at the top of the notch, an additional notchplasty was performed. The patient, who was having considerable pain before debridement, awoke from surgery pain free. At final followup examination he was stable and remained pain Arthroscopy, Vol. 7, No. 4, 1991
free. His extension had improved from 20” at predebridement to 5” 59 months post-ACL reconstruction. Case 2 A 19-year-old woman had a second-look arthroscopy to assess bilateral meniscal repairs 6 months after left knee ACL reconstruction using the middle third patellar tendon. The patient had experienced occasional popping and catching in her joint but this was unaccompanied by pain. Second-look arthroscopy confirmed that both repaired menisci were completely healed and the ACL graft was well vascularized and stable. Because the patient had been doing well, the finding of moderately severe soft tissue impingement was unexpected. There was a pedunculated ball of tibrocartilaginous tissue in the intercondylar notch and this was resected with a basket rongeur. The patient, seen at 16 months post-ACL reconstruction, remained stable, was no longer experiencing popping or catching, and was happy to have had the debridement. DISCUSSION There are several possible causes for soft tissue impingement syndrome after ACL reconstruction. Some patients appear to have a predisposition to forming an inordinate amount of postoperative scar tissue. Another possible reason for a proliferation of scar tissue may be due to an ACL graft that has been placed too far anteriorly on the tibia1 plateau. This could result in impingement on the top of the notch. A notchplasty that has not been carried out high enough superiorly to allow for the accommodation of the ACL graft during full extension may also result in a build-up of scar tissue. Ideally, after ACL reconstruction, there should be approximately 2 mm between the graft and the top of the notch, with the knee in full extension. The reason for this is that during vigorous activities associated with quadriceps contraction, the tibia may be pulled slightly anteriorly, thus eliminating the 2-mm space. Even if adequate notchplasty has been done, patients that fail to reach full extension within 2-3 weeks of surgery may fill in the space at the top of the notch with fibrous tissue, making extension more difficult to obtain. Jackson and Schaefer (10) have described a “cyclops” lesion composed of a fibrous nodule anterolateral to the tibia1 tunnel after ACL reconstruction as a cause of impingement and failure to gain
ARTHROSCOPIC
DEBRIDEMENT
full extension. They theorize that a possible etiology is the uplifting of fibrocartilaginous tissue from the tibia during the drilling of the tibia1 tunnel, and this tissue may form a nidus for a tibroproliferative process. The patients in this study were generally satisfied after the second-look procedure. The recurrence rate after arthroscopic debridement was low. Three patients in the study required more than one debridement, but these patients were treated before the advantages of a more aggressive debridement became apparent. All three patients were ultimately pleased with the results of their repeat arthroscopy. Predictably, worker’s compensation patients expressed dissatisfaction more often than did private patients. Of the worker’s compensation patients, 50% (three of six) were not improved by the procedure. In contrast, only one of 20 private patients failed to improve by final follow-up examination. No one in the study was made worse by the procedure, and there were no complications of surgery. It is of interest to note that the incidence of soft tissue impingement in acute and chronic ACL reconstructed knees did not differ, regardless of type of reconstruction. Arthroscopic debridement significantly decreased pain and crepitation (p < .OI). Although activity level and knee extension improved after debridement, there was not a significant difference (p > .05) between the two groups; both groups improved with the passage of time. Notably, arthroscopic debridement did not affect knee stability. Jackson and Schaefer (IO) emphasized improvement in knee extension after debridement of the cyclops lesion. Their 13 patients had an average of 16” loss of extension before debridement. This was reduced to 6” after debridement and to 3.8” by final follow-up. Loss of extension was present in all of these patients, whereas in our series 12 of 27 patients had full extension predebridement despite the presence of significant scar tissue anteriorly in their joints. In addition, their patients underwent a manipulation under anesthesia (MUA) along with their debridement and 46% required a second arthroscopy and MUA, whereas two (7%) of our patients
AFTER ACL RECONSTRUCTION had a manipulation under anesthesia. These data explain why our patients did not experience a dramatic gain in knee extension compared with Jackson and Schaefer’s patients. Soft tissue impingement probably occurs more frequently than commonly believed after ACL reconstruction. Even patients who have only mild symptoms of pain and crepitation may have significant fibrocartilaginous scar tissue in their joints. If this tissue can be implicated in causing articular cartilage damage through impingement and abnormal pressure during weight-bearing, then arthroscopic debridement may serve to minimize this damage and lessen the prospect of arthritis. Just as importantly, it may serve to make the patient considerably more comfortable, and therefore happier with the results of ACL reconstruction. REFERENCES 1. Scott GA, Jolly BL, Henning CE. Combined posterior
2.
3.
4.
5.
6.
7.
8
9.
IO.
incision and arthroscopic intra-articular repair of the meniscus. J Bone Joint Surg 1986;68A:847+1. Rosenberg TD, Scott SM. Coward DB, et al. Arthroscopic meniscal repair evaluated with repeat arthroscopy. Arthroscopy 1986;2: 14-20. Stone RG, VanWinkle GN. Arthroscopic review of meniscal repair: assessment of healing parameters. Arthroscopy 1986;2:77-81. Slocum DB. Larson RL. Pes anserinus transplantation. A surgical procedure for control of rotatory instability of the knee. J Bone Joint Surp 1968:50A:226-42. Sprague NF, O’Connor RL, Fox JM. Arthroscopic treatment of postoperative knee fibroarthrosis. Clin Orrhop 1982;166:165-72. Paulos LE. Rosenberg TD, Drawbert J, Manning J, Abbott P. Infrapatellar contracture syndrome. An unrecognized cause of knee stiffness with patella entrapment and patella infera. Am J Sports Med 1987;15:331-41. Cross MJ, Paterson RS, Capito CP. Acute repair of the anterior cruciate ligament with lateral capsular augmentation. Am J Sports Med 1989;17:63-7. Sachs RA, Daniel DM, Stone ML, Garfein RF. Patellofemoral problems after anterior cruciate ligament reconstruction. Am J Sports Med 1989;17:760-5. O’Brien WR, Warren RF, Friederich NF, et al. Degenerative arthritis of the knee following anterior cruciate lieament injury: a multicenter. long-term, followup study. Orthop Trans 1989;13:546. Jackson DW, Schaefer RK. Cyclops syndrome: loss of extension following intra-articular anterior cruciate ligament reconstruction. Arthroscopy 190;6: 171-8.
Arthroscopy.
Vol. 7, No. 4. 1991
by
Raven Press, Ltd. 0
1991
Arthroscopy Association of North America
The Role of Arthroscopic Debridement After Anterior Cruciate Ligament Reconstruction W. Dilworth Cannon, Jr., M.D., and Joyce M. Vittori, B.A.
Summary: This retrospective study included 55 patients who had prior anterior cruciate ligament (ACL) reconstruction; 30 made up the experimental group who had arthroscopic debridement of impinging soft tissue and 25, who did not have a second-look arthroscopy, were used as controls. Impinging tissue was
not necessarily the primary reason for arthroscopy in the experimental group. Only nine patients (30%) were debrided solely because of anterior symptoms suggestive of soft tissue impingement; 16 (53%) underwent arthroscopy primarily to assess meniscal repairs; five (17%) were done in conjunction with hardware removal. Both groups were evaluated for pain, crepitation, and anterior laxity at three specific times. Debridement reduced crepitation from 35% to 8% in patients with moderate crepitus, and from 50% to 38% in patients with mild symptoms. The percentage of patients without crepitation increased from 15% to 54% by final follow-up. Predebridement, 14% of patients had moderate pain, and 53% mild pain. By final follow-up, 38% had mild pain and 62% were pain free. Patients benefitted from debridement regardless of method of ACL reconstruction. Arthroscopic debridement did not increase anterior knee translation. Both groups gained extension and had improved activity levels with the passage of time from ACL surgery. Key Words: Debridement-Anterior cru-
ciate ligament reconstruction.
These observations were not unanticipated; the risks of such postoperative extensor mechanism problems as chondromalacia patella or degenerative joint disease after ACL reconstruction have long been recognized (4-9). Nevertheless, after resection and debridement of impinging tissue (Fig. 2), most patients were improved. This retrospective study was initiated to discern if arthroscopic debridement proved to be significantly beneficial in patients who had prior ACL reconstruction and symptoms of soft tissue impingement.
A second-look arthroscopy is an accurate and accepted means of assessing the healing status of arthroscopic meniscal repair (l-3). It was while evaluating patients arthroscopically who had anterior cruciate ligament (ACL) reconstruction in conjunction with meniscal repair that it was observed that a number of grafts had developed excessive fibrous or fibrocartilaginous scar tissue or both anteriorly in the intercondylar notch, the base of the ACL graft, or the fat pad region (Fig. 1). In addition, this soft tissue was frequently found to be impinging anteriorly in the joint during the last 10” of extension.
MATERIALS AND METHODS From the Department of Orthopaedic Surgery, Davies Medical Center, San Francisco, and The Department of Orthopaedic Surgery, University of California, San Francisco, California, U.S.A. Address correspondence and reprint requests to W. Dilworth Cannon, Jr., M.D., University of California, San Francisco, Department of Orthopaedic Surgery, 533 Pamassus Ave., Room U-158, San Francisco, CA 94143-0728, U.S.A. The technique descirbed in this article will be demonstrated in a forthcoming Video Supplement to Arthroscopy.
Of all the ACL reconstructions performed by the senior author between November 1982 and January 1988,55 patients met the criteria for inclusion in this study. These patients were divided into two groups: (a) the experimental group comprising 30 patients who had a second-look arthroscopic debridement at 344
ARTHROSCOPIC
DEBRIDEMENT
FIG. 1. Typical appearance of impinging fibrous scar tissue around the ACL graft, left knee.
least 6 months after ACL reconstruction, and (b) the control group comprised of 25 patients who did not have a second-look surgery after ACL reconstruction. In order to ensure that the control group and the experimental group approximated each other relative to time of surgery, the control group was assembled by taking in chronological order the next patient that met the study criteria. Those ex-
AFTER ACL RECONSTRUCTION
345
eluded from the study were patients that were not treated at Davies Medical Center or who were lost to follow-up examination. Also, because most of the second-look arthroscopies were performed after January 1984, this limited the number of controls selected by eliminating otherwise qualified patients treated before this date. Although all 30 patients in the experimental group had arthroscopic debridement of impinging soft tissue, this may not have been the initial or primary motive for the second-look surgery. In fact, only nine patients (30%) were debrided solely because of anterior pain or crepitation or both suggestive of soft tissue impingement (Fig. 3). Impinging scar tissue was the secondary reason for the arthroscopic debridement of the remaining 21 patients. Secondlook arthroscopy was performed in 16 of these patients (53%) primarily to assess the results of meniscal repair and in five patients (17%) whose chief complaint was hardware pain (Fig. 3). Overall, impinging soft tissue resulted in crepitation during terminal knee extension in 26 patients (87%), pain in 21 patients (70%), and both in 20 patients (67%) before debridement. Crepitation as addressed in this study refers only to anterior crepitation. Patello-femoral crepitation was not a subject of this investigation. The factors analyzed in this study were crepitation during terminal extension, pain, activity level, knee extension, and knee laxity. The evaluation of anterior knee translation was important in determining if debriding the intercondylar notch and around the anterior cruciate graft compromised the
HARDWARE PAI 17%
MENISCUS REPAIR 53% FIG. 2. Same patient after arthroscopic
debridement.
FIG. 3. Reason for second look. The patient breakdown in the experimental group. STI, soft tissue impingement; meniscus repair, second look for assessment of healing. Arthroscopy,
Vol. 7. No. 4. 1991
W. D. CANNON,
346
JR. AND J. M. VITTORI
blood supply or damaged the ACL graft, resulting in its elongation. Crepitation and pain were graded as none, mild, or moderately severe. Activity level was evaluated by whether the patient was able to return to a preinjury level of sports, to a lower level of participation or different sports, or only to activities of daily living. Anterior knee translation was measured with the Knee Laxity Tester (Orthopedic Systems Inc., Hayward, CA, U.S.A.) using 20- and 40-pound anterior forces at 25-30” of knee flexion.
EXPERIMENTAL
CONTROL GROUP
GROUP
26PTS
17PTS
26PTS
PRE
POST
FINAL
PTS
0 PTS
19 PTS
901 %
SOY 702
1
60X
T
50%
:
40%
N i
30x 2on 101 0%
RESULTS The average time from ACL reconstruction to final follow-up examination in the experimental group was 27 months (range g-60) and 23 months (range 7-52) in the control group. Patients in the experimental group had arthroscopic debridement anytime from 6 to 36 months after ACL reconstruction. The factors of crepitation, pain, knee extension, and anterior knee translation evaluated in this study could have been affected either adversely or favorably by time. Activity level was most certainly affected by time because all patients were put on a protocol restricting their activities for a full year after ACL reconstructive surgery. Therefore, in addition to an overall analysis of the data, the results of the experimental and control groups were evaluated at three specific times in order to monitor and evaluate any changes. Patients in the experimental group were examined before arthroscopy, at approximately 2 months postarthroscopic debridement, and at final follow-up examination. The average time of second-look arthroscopy in patients debrided less than 1 year after ACL surgery was 7 months. The average interval to arthroscopic debridement in patients more than 12 months after ACL reconstruction was 16 months. Accordingly, patients in the control group were evaluated at 7 and 16 months after ACL reconstruction and again at final follow-up examination. Of the 30 patients in the experimental group, 26 were followed out to final follow-up examination. The four patients not included in this aspect of the study had arthroscopy less than 2 months before final follow-up examination. Crepitation The experimental group (Fig. 4) showed a steady reduction of moderate crepitation from 35% predebridement to 18% postdebridement, and to 8% by Arthroscopy,
Vol. 7, No. 4, 1991
m
MODERATE
7 MOS m
MILD
16 MOS
0
FINAL
NONE
FIG. 4. Overall effect of arthroscopic debridement on crepitation as compared with the control group over time.
final examination. The overall reduction of moderate crepitation was statistically significant at p < .Ol.The percentage of patients without crepitus increased from 15% predebridement to 29% postdebridement and climbed to 54% by final follow-up examination (p < .Ol). In contrast, the incidence of crepitation was low in the control group and remained virtually unchanged throughout the course of the study (Fig. 4). In the experimental group, the 12 patients who had a modified Mott ACL reconstruction using doubled semitendinosus tendon were compared with the 14 patients who had reconstruction using the middle third patellar tendon (Fig. 5). The middle third patellar tendon group fared less well, with 43% of the group experiencing moderate crepitus, 50% having mild symptoms, and only 7% having no crepitation before arthroscopic debridement. Although the modified Mott group initially had only a 25% incidence of moderate crepitation, by final folMODIFIED
MOTT
MID
3RD
PAT TENDON
100%
90x %
80% 70%
1
60%
T
5on
:
4on
v s
30% 20%
0% PRE-SCOPE =
PRE-SCOPE
FINAL MODERATE
FIG. 5. Effect of arthroscopic type of ACL reconstruction.
m
MILD
debridement
0
FINAL
NONE
on crepitation
by
ARTHROSCOPIC
DEBRIDEMENT
AFTER ACL RECONSTRUCTION
low-up examination the middle third patellar tendon and the modified Mott groups had comparably good results, with moderate crepitation occurring in only 7% and 8%, respectively (Fig. 5).
Activity level There were 25 patients in the experimental and 21 patients in the control group who were more than 1 year post-ACL reconstruction and therefore no longer restricted by the dictates of their rehabilitation protocol. These patients were evaluated with regards to activity level. The findings showed that there was no statistical difference in improvement (p > .05) in activity level after arthroscopic debridement compared with the control group. A return to
/ 11
EXPERIMENTAL roou,
26 PTS m
17 PTS
GROUP
50%
%
65%
70% 1
60%
T
50%
:
40%
7 s
CONTROL 19 PTS
26 PT.9
30% 20%
GROUP
8 PTS
19 PTS
79%
PRE
POST -MODERATE
FINAL
PRE-SCOPE
FINAL
MID 3RD PAT TENDON
60th
T
50%
:
40% 30%
Y s
2on 10% 0%
=
MODERATE
FIG. 7. Effect of arthroscopic
PRE-SCOPE m
MILD
0
debridement
FINAL
NONE
on pain by type of
ACL reconstruction.
a preinjury level of activity was accomplished in nine patients (43%) in the control group and nine (36%) in the experimental group. Ten patients in the control group (48%) and 12 in the experimental group (48%) became involved in different activities or a lower level of sports. Patients who limited themselves to activities of daily living were two (9%) in the control and four (16%) in the experimental populations. Knee extension There was an improvement in knee extension among the patients in the experimental group from prearthroscopic debridement to final follow-up. Predebridement figures on 27 patients show three patients (11%) with a more than lo” flexion contracture, seven patients (26%) with a 5-10” contracture, five patients (19%) with a l-4” contracture, and 12 patients (44%) with full extension. At the time of final follow-up examination, no patients had more than a lo” flexion contracture, four patients (15%) had a 5-10” lack of extension, five patients (19%) had a 1-4” contracture, and 18 patients (66%) had achieved full extension. Because the control group had similar improvement, there was no statistical difference (p > .05) between the two groups.
.:1 16% ,\\\ 5%
0%
MOTT
70’1, 1
Pain The overall decrease of pain in patients in the experimental group was statistically significant at p < .Ol. There was a dramatic decrease in pain from 19% with moderate, and 50% with mild pain before debridement, to 0% with moderate, 35% with mild, and 65% pain free by final follow-up examination (Fig. 6). The control group had little variation in pain incidence over time. At 7 months follow-up there was a 5% incidence of moderate pain but by 16 months after ACL reconstruction, there were no further complaints of moderate pain (Fig. 6). Both modified Mott and middle third patellar tendon reconstructed patients had a similar incidence of symptoms of pain before arthroscopic debridement (Fig. 7). By final follow-up, however, the middle third patellar tendon group had a reduction of mild symptoms from 57% to 29%. The complaints of moderate pain had been eliminated in both groups.
MODIFIED
347
16 MOS
&8
MILD
0
FINAL
NONE
FIG. 6. Overall effect of arthroscopic debridement compared with the control group over time.
on pain as
Knee laxity Knee laxity testing was used to measure the involved minus uninvolved anterior translation difference in millimeters between the experimental and control groups at final follow-up examination. Patients were tested with both a 20- and 40-pound anterior force in the Lachman position. Figure 8 shows the mean translation differences between the two groups. The involved minus uninvolved difference of approximately 1 mm in both groups demonArthroscopy.
Vol. 7 No. 4. 1991
348
W. D. CANNON, 1.5,
20
LBS FORCE
JR. AND J. M. VITTORI
40 LBS FORCE
”
EXPERIYENT*L
EXP.
27; CONTROL
CONTROL
EXPERIMENTAL
CONTROL
- 20
FIG. 8. Mean laxitv difference after debridement as measured with an instrumentkd knee laxity tester with a 20- and 40-pound anterior force at final follow-up. (Experimental group: n = 27; control group: n = 20.)
strated the excellent stability of the knees tested. This was an important finding, because it illustrates objectively that there was no change in knee instability in the experimental group and that judicious debridement can be done in the intercondylar notch and around the anterior cruciate graft without jeopardizing knee stability. CASE REPORTS Case 1 A 49-year-old man was treated by second-look arthroscopy for severe soft tissue impingement syndrome 13 months after left knee ACL reconstruction with doubled semitendinosus after an ACL tear and an intercondylar eminence fracture. Arthroscopic examination showed an inordinate amount of fibrocartilaginous tissue in the front of the intercondylar notch that extended across the medial compartment to the midportion of the medial meniscus. The patient had been weight-bearing on a 4to 5-mm thick wafer of fibrocartilaginous tissue. Conventional power-driven debriders failed to remove this tissue. Instead, basket rongeurs were used to piecemeal resect it. Because it was difficult to define the outline of the ACL graft, it was necessary to painstakingly debride around the periphery of the lesion, carefully working into the intercondylar notch. Because there was some impingement during extension at the top of the notch, an additional notchplasty was performed. The patient, who was having considerable pain before debridement, awoke from surgery pain free. At final followup examination he was stable and remained pain Arthroscopy, Vol. 7, No. 4, 1991
free. His extension had improved from 20” at predebridement to 5” 59 months post-ACL reconstruction. Case 2 A 19-year-old woman had a second-look arthroscopy to assess bilateral meniscal repairs 6 months after left knee ACL reconstruction using the middle third patellar tendon. The patient had experienced occasional popping and catching in her joint but this was unaccompanied by pain. Second-look arthroscopy confirmed that both repaired menisci were completely healed and the ACL graft was well vascularized and stable. Because the patient had been doing well, the finding of moderately severe soft tissue impingement was unexpected. There was a pedunculated ball of tibrocartilaginous tissue in the intercondylar notch and this was resected with a basket rongeur. The patient, seen at 16 months post-ACL reconstruction, remained stable, was no longer experiencing popping or catching, and was happy to have had the debridement. DISCUSSION There are several possible causes for soft tissue impingement syndrome after ACL reconstruction. Some patients appear to have a predisposition to forming an inordinate amount of postoperative scar tissue. Another possible reason for a proliferation of scar tissue may be due to an ACL graft that has been placed too far anteriorly on the tibia1 plateau. This could result in impingement on the top of the notch. A notchplasty that has not been carried out high enough superiorly to allow for the accommodation of the ACL graft during full extension may also result in a build-up of scar tissue. Ideally, after ACL reconstruction, there should be approximately 2 mm between the graft and the top of the notch, with the knee in full extension. The reason for this is that during vigorous activities associated with quadriceps contraction, the tibia may be pulled slightly anteriorly, thus eliminating the 2-mm space. Even if adequate notchplasty has been done, patients that fail to reach full extension within 2-3 weeks of surgery may fill in the space at the top of the notch with fibrous tissue, making extension more difficult to obtain. Jackson and Schaefer (10) have described a “cyclops” lesion composed of a fibrous nodule anterolateral to the tibia1 tunnel after ACL reconstruction as a cause of impingement and failure to gain
ARTHROSCOPIC
DEBRIDEMENT
full extension. They theorize that a possible etiology is the uplifting of fibrocartilaginous tissue from the tibia during the drilling of the tibia1 tunnel, and this tissue may form a nidus for a tibroproliferative process. The patients in this study were generally satisfied after the second-look procedure. The recurrence rate after arthroscopic debridement was low. Three patients in the study required more than one debridement, but these patients were treated before the advantages of a more aggressive debridement became apparent. All three patients were ultimately pleased with the results of their repeat arthroscopy. Predictably, worker’s compensation patients expressed dissatisfaction more often than did private patients. Of the worker’s compensation patients, 50% (three of six) were not improved by the procedure. In contrast, only one of 20 private patients failed to improve by final follow-up examination. No one in the study was made worse by the procedure, and there were no complications of surgery. It is of interest to note that the incidence of soft tissue impingement in acute and chronic ACL reconstructed knees did not differ, regardless of type of reconstruction. Arthroscopic debridement significantly decreased pain and crepitation (p < .OI). Although activity level and knee extension improved after debridement, there was not a significant difference (p > .05) between the two groups; both groups improved with the passage of time. Notably, arthroscopic debridement did not affect knee stability. Jackson and Schaefer (IO) emphasized improvement in knee extension after debridement of the cyclops lesion. Their 13 patients had an average of 16” loss of extension before debridement. This was reduced to 6” after debridement and to 3.8” by final follow-up. Loss of extension was present in all of these patients, whereas in our series 12 of 27 patients had full extension predebridement despite the presence of significant scar tissue anteriorly in their joints. In addition, their patients underwent a manipulation under anesthesia (MUA) along with their debridement and 46% required a second arthroscopy and MUA, whereas two (7%) of our patients
AFTER ACL RECONSTRUCTION had a manipulation under anesthesia. These data explain why our patients did not experience a dramatic gain in knee extension compared with Jackson and Schaefer’s patients. Soft tissue impingement probably occurs more frequently than commonly believed after ACL reconstruction. Even patients who have only mild symptoms of pain and crepitation may have significant fibrocartilaginous scar tissue in their joints. If this tissue can be implicated in causing articular cartilage damage through impingement and abnormal pressure during weight-bearing, then arthroscopic debridement may serve to minimize this damage and lessen the prospect of arthritis. Just as importantly, it may serve to make the patient considerably more comfortable, and therefore happier with the results of ACL reconstruction. REFERENCES 1. Scott GA, Jolly BL, Henning CE. Combined posterior
2.
3.
4.
5.
6.
7.
8
9.
IO.
incision and arthroscopic intra-articular repair of the meniscus. J Bone Joint Surg 1986;68A:847+1. Rosenberg TD, Scott SM. Coward DB, et al. Arthroscopic meniscal repair evaluated with repeat arthroscopy. Arthroscopy 1986;2: 14-20. Stone RG, VanWinkle GN. Arthroscopic review of meniscal repair: assessment of healing parameters. Arthroscopy 1986;2:77-81. Slocum DB. Larson RL. Pes anserinus transplantation. A surgical procedure for control of rotatory instability of the knee. J Bone Joint Surp 1968:50A:226-42. Sprague NF, O’Connor RL, Fox JM. Arthroscopic treatment of postoperative knee fibroarthrosis. Clin Orrhop 1982;166:165-72. Paulos LE. Rosenberg TD, Drawbert J, Manning J, Abbott P. Infrapatellar contracture syndrome. An unrecognized cause of knee stiffness with patella entrapment and patella infera. Am J Sports Med 1987;15:331-41. Cross MJ, Paterson RS, Capito CP. Acute repair of the anterior cruciate ligament with lateral capsular augmentation. Am J Sports Med 1989;17:63-7. Sachs RA, Daniel DM, Stone ML, Garfein RF. Patellofemoral problems after anterior cruciate ligament reconstruction. Am J Sports Med 1989;17:760-5. O’Brien WR, Warren RF, Friederich NF, et al. Degenerative arthritis of the knee following anterior cruciate lieament injury: a multicenter. long-term, followup study. Orthop Trans 1989;13:546. Jackson DW, Schaefer RK. Cyclops syndrome: loss of extension following intra-articular anterior cruciate ligament reconstruction. Arthroscopy 190;6: 171-8.
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