Anterior cruciate ligament - updating article

Remnant preserving ACL reconstruction with a functional remnant is related to improved laxity but not to improved clinical outcomes in comparison to a nonfunctional remnant

PURPOSE

The Anterior cruciate ligament (ACL) remnant has been pointed out as a ligamentization enhancer. Nonetheless, the remaining tissue can be functional if it still provides some stability or nonfunctional. This study intends to compare the clinical results and knee stability of functional vs. nonfunctional remnant preservation ACL reconstruction (ACLR).

METHODS

One hundred and seventy-five patients with ACL injuries were included and underwent remnant preservation ACLR. They were divided into two groups accordingly to remnant tissue functionality: functional (Group F) and nonfunctional (Group NF). Primary outcome was defined as patient reported outcomes measured with Lysholm, IKDC and Tegner continuous scales and improvements. Secondary outcomes comprised of Lachman test, anterior drawer test, pivot shift test, extension and flexion deficit, graft coverage by remnant preserved tissue and failure rate (persistent instability or new ACL lesion). Menisci lesions, cartilage lesions and time to surgery were also recorded for each group.

RESULTS

One hundred and forty-four patients were available at a mean of 30.2 ± 10.1 months: 69 Functional and 75 Nonfunctional. Lysholm, IKDC and Tegner functional outcomes demonstrated no difference between the groups, Functional compared to Nonfunctional: 88.4 ± 10.5 vs. 92.2 ± 4.9, n.s. and 83.2 ± 11.3 vs. 87 ± 5.3, n.s. and 6 (5-10) vs. 6 (5-9), n.s., respectively. Lysholm and IKDC functional outcomes improvements demonstrated differences between the groups: Functional compared to Nonfunctional (39.3 ± 9.4 vs. 42.3 ± 7.4, p = 0.014 and 37.7 ± 10 vs. 41.0 ± 6.6, p = 0.032); however, they were not clinically significant. Functional group showed more stability on physical examination pre- and post-operatively (p < 0.001, p < 0.001). There was no difference regarding extension deficit (n.s.); however, functional group had more flexion deficit (p = 0.02). Nonfunctional group had better graft coverage (p = 0.001). There was no difference regarding failure rate: 4% vs. 9%, (n.s.).

CONCLUSION

Both remnant preservation ACLR techniques were able to achieve satisfactory functional outcomes. A functional remnant was not related to improved functional outcomes in comparison to a nonfunctional remnant; however, it was related to less laxity pre and postoperatively and inferior graft coverage.

LEVEL OF EVIDENCE

II.

ANALYSIS OF THE MECHANICAL BEHAVIOR OF THE POSTERIOR CRUCIATE LIGAMENT IN A PORCINE MODEL

INTRODUCTION

The knee has shown a significant increase in the frequency of injury due to sports practice. This increase and the improvement of surgical techniques of ligament reconstruction have led to a greater indication of this treatment to achieve a function close to normal.

OBJECTIVE

To conduct a preliminary analysis of the ligament behavior.

METHODS

The study consisted of the validation of an anatomical model of the pig, in which five models were subjected to mechanical tests. The data on the loads of the in situ model and the strains of the posterior cruciate ligament were collected.

RESULTS

The analysis of the tensile load showed, at first, a nonlinear increase in stresses. Subsequently, the pig's knee showed a relatively linear intermediate response until failure around 1,200 N. Strain × time showed a response of the posterior cruciate ligament, which also has a relatively linear response.

CONCLUSION

We observed a linear behavior in the range of 1,000 to 5,000 microstrains in the strain of the posterior cruciate ligament. We suggest further studies to understand knee ligaments regarding their behavior in their function. Level of Evidence IV, Biomechanical Study.

Return to Sports after ACL Reconstruction with Resection or Remnant-Preserving Technique

Objectives  To analyze the results of anterior cruciate ligament (ACL) reconstruction with remnant-preserving versus remnant-resecting technique, concerning the return to pre-lesion activity level.

Methods  The present retrospective cohort study has assessed adults > 18 years old who underwent ACL anatomical reconstruction between 2010 and 2014. The main outcomes assessed were: level of physical activity (4-point scale), sports participation rate, ACL rerupture defined as documented lesion requiring revision surgery and the numeric pain scale rate (NPSR).

Results  A total of 83 individuals were included in the study, with a mean age of 31.8 years old and follow-up mean time of 4.2 years after the surgery. A total of 34 patients underwent ACL reconstruction with remnant-preserving technique, and 49 without remnant preservation. No statistically significant difference was found between groups in all outcomes assessed: level of physical activity before the lesion and after the surgery, ACL rerupture rates and postoperative pain level. Subgroup analysis has shown a statistically significant decrease in the activity level in both groups. The most practiced sport was football; 72% of patients in the remnant group have resumed football activity versus 52.6% of the control group.

Conclusion  Based in these findings, the comparison between ACL reconstruction with remnant preserving technique and remnant resecting technique has shown no differences concerning the return to prelesion activity level.

Treatment of Anterior Cruciate Ligament Injuries in Professional Soccer Players by Orthopedic Surgeons

Objective  To describe the treatment provided by specialists for ACL lesions in professional soccer players. Methods  A cross-sectional study in which orthopedic surgeons affiliated to soccer teams competing in the Brazilian Soccer Championship answered a questionnaire about the treatment of ACL injuries in professional soccer players. Results  The specialists wait between one to four weeks after the ACL injury to perform the surgical treatment. They use a single incision and single-bundle reconstruction, assisted by arthroscopy, femoral tunnel drilling by an accessory medial portal, and quadruple flexor tendon autografts or patellar tendon autografts. After three to four months, the players are allowed to run in a straight line; after four to six months, they begin to practice exercises with the ball without contact with other athletes; and, after six to eight months, they return to play. The main parameter used to determine the return to play is the isokinetic strength test. The specialists estimate that more than 90% of elite soccer players return to playing professionally after an ACL reconstruction, and 60 to 90% return to play at their prior or at a greater level of performance. Conclusion  The present article successfully describes the main surgical practices and post-surgery management adopted by specialists in this highly-specific population of patients.

Modified Lemaire Lateral Tenodesis Associated With an Intra-articular Reconstruction Technique With Bone-Tendon-Bone Graft Using an Adjustable Fixation Mechanism

The goal of this study was to report a surgical technique used in a revision anterior cruciate ligament (ACL) reconstruction case, consisting of an adaptation of the anterolateral iliotibial band tenodesis technique (modified Lemaire technique) combined with ACL reconstruction using an adjustable fixation mechanism. Rotational overload was one of the most likely hypotheses for failure of primary surgery, despite correct positioning and secure fixation. We performed a review of the most pertinent factors related to ACL reconstruction failure, as well as surgical strategies for its treatment. After this, we described, step by step, a combination of the 2 forms of surgical intervention that were already presented isolated with good clinical results, correcting the common anterior and rotational instabilities found in these cases. Knowing new techniques for intra- and extra-articular ligament reconstruction is imperative in the present day, when more patients are seeking a full return to their preinjury recreational, labor, and sports activities. We believe that the combination of these surgical techniques is able to achieve these goals effectively and reproducibly.

Laser-guided transtibial technique improved single-bundle reconstruction of anterior cruciate ligament

Background

The transtibial tunnel technique achieves equal length reconstruction of the anterior cruciate ligament (ACL). This study aimed to investigate whether transtibial tunnel technique can achieve anatomical reconstruction of ACL.

Methods

For 25 corpses, the anterior soft tissue of the knee joint was detached so that the ligamentous surface was fully exposed, then the knee joint was fixed at 90° with an external fixator and the anterior cruciate ligament was removed. Double-sided laser technology was used to establish spatial conformation of ACL.

Results

The male to female ratio of the subjects was 19:6, with an average age of 59.52 ± 11.13 years. Patellar tendon length was 35.23 ± 5.10 mm, tibial eminence length and width was 15.75 ± 2.44 and 7.80 ± 1.28 mm, respectively, and femoral attachment length and width was 15.40 ± 2.17 and 8.97 ± 1.61 mm, respectively. When the flexion turned 90°, the tibial tunnel length was 31.83 ± 4.09 mm and the distance to the tibial plateau, patellar tendon, and medial collateral ligament was 16.33 ± 4.56, 10.79 ± 5.85, and 23.12 ± 5.99 mm, respectively.

Conclusions

With the aid of double-sided laser technology, transtibial tunnel technique can safely achieve single-bundle reconstruction of ACL.

An animal model of reconstruction of single femoral tunnel with single bone bi-quadruple ACL and internal fixation

We introduced several variables in an animal model of anterior cruciate ligament (ACL) reconstruction to determine the best parameters for surgery in humans. We divided 130 LYD pigs into two groups depending on whether the femoral tunnel goes through the medial tibial tunnel or through the medial fossa of the knee joint. Each subgroup was further divided. Four weeks after surgery the knee specimens were examined for passive flexion and extension test. No group showed a creep effect. In the biomechanical tests, we recorded maximal strength, maximum load, and stiffness parameters. The 100° + 1.0 mm, 1.5 mm, and 2.0 mm positions of the tibial tunnel group, and 10.5 (1.5) + 1.0 mm, 1.5 mm, and 2.0 mm positions of the knee joint cavity group had better biomechanical effects, histocompatibility and revascularization in ACL reconstruction. Overall, these results demonstrated significant differences in the effectiveness of ACL reconstruction based on several surgical parameters, which should contribute to establishing a gold standard for ACL surgery in patients.

Intra-articular Anterior Cruciate Ligament Reconstruction With Extra-articular Lateral Tenodesis of the Iliotibial Band

An increasing concern has been given to the rotation stability of the knee in the setting of an anterior cruciate ligament (ACL) reconstruction. This growing interest stems from a better understanding of the rotational stability of the knee afforded by the identification of the anterolateral ligament. Previously, a residual abnormal pivot-shift test had been found after an anatomic single-band reconstruction of the ACL because of a lack of rotational stability, which may lead to the development of osteoarthritis. Residual instability affects function, especially in high-demand athletes who perform many flexion-rotation movements during sporting activity. The purpose of this Technical Note is to describe our preferred method of intra-articular ACL reconstruction using a hamstring tendon autograft in combination with an extra-articular iliotibial band tenodesis for reinforcement of rotational stability.