Keywords
reconstruction - anterior cruciate ligament - lateral extra-articular tenodesis -
failure
Introduction
Anterior cruciate ligament (ACL) injuries are high-frequency events with a reported
overall incidence of 68.6 cases per 100,000 people per year.[1] The ACL plays a critical role in the mechanical stability of the knee. In situations
where this noble ligament experiences a complete rupture of its fibers, it is usually
recommended to perform a surgical reconstruction with the aim of restoring the stability
of the joint, preventing secondary injuries to the meniscus, articular cartilage,
and reducing the development of knee osteoarthritis.[2]
[3]
ACL reconstruction surgery has made significant advances in recent decades,[4] and although the results of ACL reconstruction with modern surgical techniques are
extremely positive, 90% of patients report normal or near-normal knee function, 82%
successfully return to sports, 63% regain their pre-injury level of participation,
and 44% return to competitive sports, the development of the technique is far from
perfect. To this day, specific groups of patients report high rates of graft rupture.[5]
[6]
Due to the ever-growing need to improve clinical results and reduce surgical failure
rates, a scenario of interest has been configured for the implementation of new techniques
during ACLR.[7] One of the most notable developments in this field has been in relation to the understanding
of the anterolateral complex of the knee, a field in which multiple extra-articular
surgical techniques have been described with the intention of providing better rotational
stability to our ACLR.[8]
[9]
[10]
Lateral extra-articular tenodesis (LEAT) was initially described in the 1960s and
1970s as an isolated procedure aimed at controlling anterolateral rotational laxity
in knees with ACL deficiency, in a period when intra-articular ACLRs were not performed.[10] After having been partially abandoned, with the advent of intra-articular reconstructions,
this technique regained prominence, especially in the group of young, athletically
demanding patients, who have exponentially higher risks of post-ACLR failure.[10]
To date, multiple configurations have been described for this anterolateral reinforcement,
one of the most used being the modified Lemaire technique, in which the central third
of the iliotibial band is harvested with a length of approximately 8 - 10 centimeters,
then passed under the lateral collateral ligament and is attached proximal and posterior
to the lateral epicondyle.[11]
The advantages of the LEAT have attracted the attention of the global community of
orthopedic surgeons, with growing curiosity about the possible clinical applications,
highlighting the aforementioned work of the STABILITY group, who found that by adding
a LEAT in primary reconstructions with semitendinosus gracilis-autograft in patients
younger than 25 years, there was a relative risk reduction for graft rupture of 0.67
(95% CI, 0.36-0.83; P < 0.001), with a number needed to treat to prevent a re-rupture
at two years of 14.3 patients.[12]
Despite the advantages reported with the implementation of this technique, the frequency
and magnitude of its application are not adequately described in the literature, and
this knowledge gap deepens even further in our Latin American environment. We know
that the balance has been tipping towards its indication frequently, but we do not
know how big this change has been in the primary ACLR algorithm.
Having said the above, the present work aims to address this gap, focusing on the
trend and frequency of LEAT indication in primary RLCA and how this procedure has
been gaining space during the last 5 years in our institution.
Materials and methods
The institution's ethics committee approved the registration and use of clinical scores
and demographic information in a prospective longitudinal database (REDCap, Vanderbilt
University). Patients signed an informed consent during pre-surgical evaluations for
the potential use of their information in an anonymized manner in future reports and
retrospective studies.
The database was analyzed to identify those patients who underwent primary ACL reconstruction
surgery between 2018 and 2023. Cases of patients over 14 years of age who underwent
primary ACL reconstruction surgery were included. All patients undergoing revision
surgeries, multiligamentous injuries, and those with associated fractures were excluded.
The technique used as LEAT was the modified Lemaire technique ([Fig. 1]), which consists of passing the central third of the iliotibial band under the lateral
collateral ligament, to then be fixed posteriorly and cephalad to the lateral epicondyle.
Fig. 1 Scheme illustrating the modified Lemaire technique, the central third of the iliotibial
band is harvested, then passed under the lateral collateral ligament and fixed posteriorly
and proximally to the lateral epicondyle with an anchor.
The general indications used as a working group for recommending LEAT in primary ACL
reconstructions are patients under 25 years old, hyperlax patients, those participating
in pivoting sports such as soccer or skiing, high-performance athletes, and those
with a high-grade pivot shift test (≥ 2).
Descriptive statistics were performed for variables including age, sex, graft type,
and the performance of LEAT during surgery. The Prais-Winsten test was used to analyze
the trend of the procedure over time. For the bivariate analysis of the association
between sex, graft type, year, and LEAT, the Chi-square test was applied.[2] For the bivariate analysis between age and LEAT, the Student “t” test was used.
With the information obtained, a multiple logistic regression model was built. Statistical
significance was established with p < 0.05 and α = 5%. STATA statistical software
version 17.0 (StataCorp, TX) was used.
Results
922 patients who met both the inclusion and exclusion criteria were included, of which
235 (25.4%) were women and 687 (74.6%) men with a mean age of 30.2 years. 48% of the
patients presented a pivot shift of at least second degree, within the other 52% who
presented a low-grade pivot shift test, the indication was related to the age of the
patients, laxity, and sports activities performed.
Of the total sample size, 14.21% of patients underwent LEAT in the context of primary
ACLR, while 85.79% did not perform any lateral extra-articular gesture. The frequency
of this indication varied annually, initially being 4% in 2018, to finally reach a
maximum of 29.3% during 2023 ([Fig. 2]). Regarding the type of graft, hamstring autograft was used mostly in 692 cases
(75.05%), autologous bone-tendon-bone graft in 209 cases (22.56%) and allograft in
21 cases (2.28%).
Fig. 2 Graph illustrating the trend of indication for lateral extra-articular plasty in
patients undergoing first ACL reconstruction. The breakdown is made year by year,
and linear growth is observed, whereas in the last year (2023) there is almost a 30%
indication of the procedure in question.
In the bivariate analysis, a significant difference was found according to age and
LEAT performance (p < 0.001) ([Fig. 3]), on the other hand, no significant association was found between sex and LEAT indication
(p = 0.36). The association between the type of graft used and performance of LEAT
was significant (p = 0.004), being mostly indicated in the context of reconstructions
with bone tendon bone (BTB) graft.
Fig. 3 Graph where we can see that the indication for LEAT occurs more frequently in young
patients, with a statistically significant relationship in its indication (P < 0.001).
On the ordinate axis we find the age, and on the abscissa, the number “1” represents
the addition of LEAT.
In the multiple logistic regression model, only age showed a significant association
with LEAT, with a decrease of 8.8% in the indication per incremental point (p < 0.001).
According to the Prais-Winsten test, there is an upward trend in the indication of
LEAT in the period studied with an annual growth of 4.75%; This data being statistically
significant (p = 0.02).
Discussion
Evolution of the indication
The results presented in this study provide an illuminating view on the trend of increase
in the indication for LEAT in primary LCAR surgeries, the most relevant element being
the surprising growth rate of 4.75% per year.
The Latin American consensus published in 2022 by Barahona et al. showed that experienced
knee surgeons indicate, on average, a lateral gesture in 24% of their primary LCAR,[13] a number quite similar to the average obtained from the last two years (2022–2023)
evaluated in our study (26.4%).
Initially, lateral procedures were indicated mainly in the context of ACL revisions
and patients with a pivot shift test ≥ 2, later including hypermobile patients and
those who practiced sports involving pivot shifts such as soccer or basketball. Among
the evidence that supports this procedure, a work consisting of ACL revisions with
high-grade knee laxity (Pivot shift of ≥ 2 or a side-to-side difference greater than
6 mm) stands out, in which Alm et al reported that The addition of LEAT led to a decrease
in failure rates from 21% to 5% (p = 0.045) when a lateral gesture was added, as well
as an increase in postoperative functional scores.[14]
Recent cadaveric studies have given great importance to the addition of this lateral
extra-articular gesture, demonstrating that adding a LEAT results in an anterior tibial
translation and tibiofemoral kinematics closer to the native one, compared to isolated
ACL reconstruction.[15]
[16]
Over time, these lateral procedures have gained popularity, becoming more easily indicated,
due to the clinical benefits that have been demonstrated in multiple studies in recent
years.
Changes in the trend
In this study, we found a significant increase in the indication of LEAT from 2018
to 2023, evolving from a relatively uncommon procedure to being performed in approximately
one-third of primary reconstruction surgeries. This finding is of particular interest
as it reflects a shift in the management of patients with ACL injuries, emphasizing
the addition of new techniques to achieve better clinical outcomes. A possible explanation
for this trend is the growing recognition of the importance of rotational and anterolateral
stability in anterior cruciate ligament reconstruction.
We conducted a focused analysis of 2022 and 2023, the years in which the high trend
of LEAT indication was sustained. Notably, LEAT was more frequently performed in cases
using BPTB grafts: in 2022, 37.11% of patients operated with this graft underwent
LEAT, compared to 12% of patients operated with hamstring grafts. In 2023, these figures
were 42.86% for bone-patellar tendon-bone (BPTB) grafts versus 25% for hamstrings.
Based on our experience, this finding may relate to the higher use of BPTB grafts
in athletes at our center, particularly those practicing pivoting sports such as soccer,
basketball, or skiing.
Another potential advantage of adding LEAT is highlighted by Lars Engebretsen's group,
who reported a 43% reduction in forces exerted on the ACL graft when a lateral procedure
is included, thereby reducing the risk of re-rupture. .[17]
In relation to the technique used, it was created as an alternative approach in the
effort to improve the rotational stability of ACL reconstruction. There are different
types of modified LEAT.[18] In our case, the technique we use is a modification of the one initially described
by Lemaire in the 1960s,[11] which consists of passing a central third of the iliotibial band, approximately
8 centimeters long by 1 centimeter wide, under the lateral collateral ligament, and
then fix it posteriorly and proximally to the lateral epicondyle, in most cases with
a 5.0 millimeter anchor with an orientation of 20° anteriorly and with a flexion of
30° knee, with neutral rotation, thereby avoiding possible over-constrictions and
convergence of tunnels.
The relationship between the age of the patients and the indication for LEAT is also
noteworthy. The data reveal that the probability of undergoing surgery decreases as
the age of the patients increases. This suggests that TEA is considered more relevant
and beneficial in younger patients (generally under 25 years of age, but this remains
a debatable factor), which could be associated with sports practices or a certain
laxity typical of early ages. Young ages have always been associated with a higher
risk of failure in ACLR; the MOON group reported that the risk of rerupture increased
by 9% for each year that the age of the subjects in their study decreased[19]. Furthermore, Schulemberg et al. demonstrated that patients under 25 years of age
had a six-fold higher risk of ACL re-rupture than patients over 25 years of age[20]. The average age of our sample was 23.7 years, a number that is within the parameters
published in the current literature. Furthermore, the average age of patients who
were indicated for LEAT was significantly younger than that of those who were not
indicated for plasty (23.7 years versus 31.3 years), further supporting this observation.
This difference in age could be related to the functional demand of the joint and
the need for greater stability in younger, more active patients.
The choice of graft type is also an important aspect of the study. Hamstring tendon
autograft stood out as the most common, used in approximately 75% of cases. This suggests
that at least in our center it continues to be a preferred option in clinical practice,
a trend that we believe could change in the future given the importance that the use
of BTB autograft has regained. At the local level, there is a study by Dr. Tuca from
2020, where 103 Chilean knee surgeons were surveyed, highlighting 70% preference for
the use of hamstring autograft in primary ACLR, and 27% by bone tendon bone autograft.[21] In this study, from a few years ago, another particular fact stands out: only 7%
of surgeons indicated a lateral procedure in primary reconstructions, which is similar
to the percentages reported by us in 2018 where we found close to 4% of primary indications
of ACL.
The annual growth trend in the indication for plasty is one of the most important
findings, highlighting the evolution of clinical practice in this field. The 4.75%
annual increase suggests that LEAT is becoming increasingly relevant in primary reconstruction
surgery. It can be speculated that by 2027, we will be recommending LEAT procedures
in approximately 50% of our primary reconstruction surgeries. Therefore, as a group,
we suggest that new orthopedic surgeons start familiarizing themselves with this technique,
which in most cases adds no more than 20 minutes to surgical time.
Finally, as a group, we would like to recommend considering the application of LEAT
in patients under 25 years old, ACL revisions, hyperlax patients, pivoting athletes,
high-performance athletes, and patients with an explosive pivot shift (≥2).
Conclusion
The results of this study indicate a significant change in clinical practice related
to the indication of LEAT in primary reconstruction surgeries. The trend towards greater
use of anterolateral plasty, especially in younger patients and in combination with
bone tendon bone autograft, suggests a response to the functional and sporting demands
of patients. These findings are relevant to orthopedic surgeons and may influence
decision-making when planning primary reconstruction surgeries in the future.
