Keywords
anterior cruciate ligament - revision surgery - contralateral - hamstring tendons
- return to sports
Introduction
The number of revision anterior cruciate ligament (ACL) surgery has risen over the
past few years.[1] Revision ACL surgery is recommended for patients who have symptomatic objective
pathological laxity after a failed primary ACL reconstruction.
The choice of graft in revision surgery remains a debatable issue. Autografts constitute
a popular choice as many authors recommend autografts both for primary and revision
ACL reconstruction.[1]
[2]
[3]
[4]
[5]
[6] Bone-patellar tendon-bone (BPTB) is frequently used as preferred graft source for
ACL reconstruction in case of hamstring failure and vice versa.[7] To minimize donor-site morbidity and to reduce operative time and incisions, allografts
have been gaining in popularity over the past few years.[8] In addition, contralateral doubled gracilis and semitendinosus tendon (DGST) graft
or BPTB has been proposed as a viable option for ACL revision surgery.[7]
[9]
The aim of this study was to evaluate the clinical outcome of ACL revision surgery
using the contralateral hamstring tendon autografts. The hypothesis of the study was
that contralateral hamstring tendon autograft in ACL revision surgery provides a satisfactory
outcome, specifically with regard to patient satisfaction, return to sports and to
preinjury activity level, and knee function.
Methods
Participants
Between 2004 and 2011, 23 patients underwent revision ACL reconstruction with contralateral
autogenous hamstring tendon grafts and were retrospectively reviewed at an average
follow-up of 6.3 years. Inclusion criterion was failed primary ACL reconstruction,
confirmed by recurrence of giving-way episodes and revealed by positive Lachman and
pivot-shift tests. Exclusion criteria were multiligament knee injuries, contralateral
instability or other significant knee diseases, severe chondral damage (grade 3 or
4 according to the Outerbridge classification system), and degenerative arthritis
(Ahlback grade 3 of 4). [Table 1] shows complete demographic and anthropometric data.
Table 1
Patient demographics and anthropometric data
|
No. of patients
|
23
|
|
Gender (male/female)
|
14/9
|
|
Mean time from reinjury to surgery (mo) (mean ± SD)
|
6.6 ± 1.2
|
|
Weight (kg) (mean ± SD)
|
70.5 ± 6.9
|
|
Height (cm) (mean ± SD)
|
172.7 ± 6.4
|
|
Age at surgery (y) (mean ± SD)
|
26.8 ± 8.8
|
Abbreviation: SD, standard deviation.
Written informed consent was obtained from all the patients. The local ethic committee
approved the study.
Interventions
Preliminary arthroscopic evaluation was performed to confirm the diagnosis. Patients
were excluded from the study when intraoperative findings did not match inclusion
criterion.
Hamstring tendon grafts were harvested from the contralateral knee with a tendon stripper
through an incision over the pes anserinus on the anteromedial aspect of the tibia
and then prepared to form a four-strand graft. Tibial and femoral tunnels were drilled
with an arthroscopically assisted transtibial technique. After the remnant of the
torn ACL graft was removed, the tibial tunnel was drilled with the aid of a compass
guide (Acufex, Smith & Nephew, Andover, Massachusetts, United States) at a 55-degree
angle in the horizontal plane on the tibial plateau. The femoral tunnel was then drilled
on the lateral wall of the intercondylar notch with the knee flexed at 90 to 120 degrees,
to a depth of 30 mm. Tunnel diameter was matched with the width of the prepared graft.
In most cases, tunnels from primary ACL reconstruction were correctly placed and could
therefore be reused for revision surgery after accurate redrilling. In those cases
in which tunnels were reoriented, care was taken to avoid convergence with the previous
tunnels. Then, the graft was fixed proximally with the use of a Tightrope device (Arthrex,
Naples, Florida, United States). Distal fixation was achieved through a BioRCI screw
(Smith & Nephew), having a diameter 1 or 2 mm larger than that of the graft, while
the knee was kept at 20 degrees of flexion and the graft under maximal manual tension.
For the first 4 weeks after surgery, walking with partial weight-bearing was allowed
with the use of two crutches. Full weight-bearing was allowed as tolerated on the
harvested knee. Patients were encouraged to regain proprioception with the use of
a balance board and complete knee flexion and extension. Closed kinetic chain exercises
were performed for the first 3 months, and thereafter open kinetic chain exercises
were started. Swimming and indoor cycling were permitted after 12 weeks, jogging and
noncontact sports were permitted after 5 months, and a return to contact sports was
allowed after 6 months.
Outcome Measurements
Patients were evaluated preoperatively and after an average follow-up of 6.3 years
(range: 2–8 years). Assessment included Knee Osteoarthritis Outcome Score (KOOS),
International Knee Documentation Committee (IKDC) Subjective Knee Form, and Tegner
activity level score. Objective examination included instrumented laxity test with
KT-1000 arthrometer (MEDmetric Corporation, San Diego, California, United States)
under a 134-N anterior tibial load. All patients were evaluated by the same examiner.
Data Analysis
Data extracted were analyzed using the software SPSS Version 19.0 (SPSS Inc., Chicago,
Illinois, United States). Wilcoxon test was used to compare the preoperative and follow-up
status. Differences with a p-value of <0.05 were considered statistically significant.
Results
No major complications were reported. Subjectively, all patients were satisfied with
their revision ACL reconstruction. The mean KOOS significantly increased from a preoperative
mean of 62.8 ± 8.3 to 85.8 ± 6.9 (p < 0.001). IKDC subjective score significantly improved from 29.2 ± 10.4 to 72.8 ± 5.2
(p< 0.001). The median Tegner activity score significantly improved from a preoperative
mean of 6.5 (range: 4–10) to 7.5 (range: 7–10) (p < 0.001). Lachman test and pivot-shift test were significantly improved when compared
with preoperative status (p < 0.001). The mean KT-1000 value (side-to-side difference) was 1.7 ± 2.4 mm. Of the
patients, 21 (91%) reported a value equal to or less than 3 mm compared with the contralateral
knee. A detailed overview of the results of overall clinical assessment is shown in
[Table 2].
Table 2
Overview of the results of clinical assessment
|
Preoperative
|
Postoperative
|
p-Value
|
|
KOOS (mean ± SD)
|
62.8 ± 8.3
|
85.8 ± 6.9
|
p < 0.001
|
|
IKDC subjective score (mean ± SD)
|
29.2 ± 10.4
|
72.8 ± 5.2
|
p < 0.001
|
|
Tegner activity level score [median (range)]
|
6.5 (4–10)
|
7.5 (6–10)
|
p < 0.001
|
|
Positive Lachman test (n [%])
|
23 (100)
|
0 (0)
|
p < 0.001
|
|
Positive pivot-shift test (n [%])
|
23 (100)
|
2 (9)
|
p < 0.001
|
|
KT-1000 (side-to-side difference) (mm) (mean ± SD)
|
5.8 ± 1.8
|
1.7 ± 2.4
|
p < 0.001
|
Abbreviations: IKDC, International Knee Documentation Committee; KOOS, Knee Injury
and Osteoarthritis Outcome Score; SD, standard deviation.
Of 23, 17 (74%) increased or returned to the same activity prior to injury and 61%
of the patients returning to cutting and pivoting sports ([Table 3]).
Table 3
Overview of sports activity preoperatively and at follow-up
|
Preinjury, n (%)
|
Post-operative, n (%)
|
|
Jumping, pivoting, cutting
|
16 (70)
|
14 (61)
|
|
Swimming, cycling
|
7 (30)
|
7 (30)
|
|
No sports
|
0 (0)
|
2 (9)
|
|
Change in sports activity
|
|
|
|
Increased level
|
|
2 (9)
|
|
Same level
|
|
15 (65)
|
|
Decreased level
|
|
4 (17)
|
|
No participation
|
|
2 (9)
|
One patient had mild contralateral harvest site symptoms. No subjective loss of motion
or strength of the contralateral knee nor long-term significant morbidity at follow-up
were reported.
Discussion
This study shows favorable results for revision ACL reconstruction with contralateral
hamstring tendon autografts concerning subjective knee function and knee stability,
as well as ability to resume sports activities. Results are comparable to the most
satisfactory outcomes reported in the literature.[1]
[7]
Subjectively, all patients reported that they would have the surgery again and were
satisfied compared with their prerevision status. After an average time of 6 years
from surgery, mean KOOS was 85.8, whereas subjective IKDC score was 72.8. None of
the patients reported knee instability. Concerning anterior tibial translation, mean
side-to-side KT-1000 value significantly improved form preoperative status.
Return to sports following ACL surgery, and the capacity of resuming sporting activities
comparable to those engaged prior to the traumatic injury, is a major concern for
patients undergoing ACL surgery.[10] Shelbourne et al[11] reported a rate of return to sports ranging from 62 to 74% in athletes who underwent
revision ACL reconstruction with a patellar tendon autograft.
In our case series, 74% of patients were able to return to their preinjury level of
sports activity. This result is in line with that of other studies with similar follow-up.[12] It has been previously demonstrated that improved sports function following ACL
revision surgery is obtained when an autograft is used.[13] Revision ACL reconstruction with DGST contralateral graft may therefore be one possible
option in patients with recurrent knee instability following primary repair who wish
to return to their preinjury activity level.
Donor-site morbidity represents a major concern in case of tendon harvesting from
a healthy knee. In our case series, no complications were observed, and at subjective
evaluation, only one patient reported mild contralateral harvest site symptoms.
Limitations of this study include its retrospective nature, its relatively small sample
size, and the lack of a control group.
In conclusion, the use of contralateral hamstring tendon autografts is a valid therapeutic
option for ACL revision surgery and confirms subjective and objective clinical improvement
6 years after surgery.
