TECHNICAL NOTE

 

Modification of the Micheli-Kocher Technique with Anterior Cruciate Ligament Remnant Preservation and Augmentation in Pediatric Patients: A Technical Note

 

Genaro R. Cucalón,* Gerardo Fernández-Staudacher, * Daniel Veloz Serrano**

*Orthopedics and Traumatology Service, Hospital de Pediatría “Prof. Dr. Juan P. Garrahan”, Autonomous City of Buenos Aires, Argentina

**Orthopedics and Traumatology Service, Hospital Británico de Buenos Aires, Autonomous City of Buenos Aires, Argentina

 

ABSTRACT

Objective: To describe a modification of the Micheli-Kocher technique that incorporates anterior cruciate ligament (ACL) remnant preservation and augmentation to enhance biological potential in skeletally immature patients. Materials and Methods: The surgical procedure is described in an 8-year-old boy (Tanner stage I) who competes in motocross. The key modification involves using an arthroscopic shaver to create an oblique opening in the superolateral portion of the remnant, through which the iliotibial band graft is passed. This allows the remnant tissue to provide biological support and guide the neoligament. Results: At the 12-month follow-up, the patient’s knee was clinically stable (negative Lachman and pivot-shift tests), and radiographs showed no limb length discrepancies or angular deformities. He successfully returned to high-impact competitive sport (motocross), with marked proprioceptive recovery and full range of motion. Conclusions: This technical modification combines the mechanical safety of extraphyseal reconstruction with the potential biological benefits of remnant preservation. The technique was a safe alternative in this single case; however, studies with a higher level of evidence are needed to confirm its comparative advantages in ligamentization and proprioception.

Keywords: Anterior cruciate ligament; pediatrics; Micheli-Kocher technique; remnant preservation; iliotibial band.

Level of Evidence: IV

 

Modificación de la técnica de Micheli-Kocher con preservación y aumentación del remanente del ligamento cruzado anterior en pacientes pediátricos: nota técnica

 

RESUMEN

Objetivo: Describir una modificación de la técnica de Micheli-Kocher que integra la preservación y aumentación del remanente del ligamento cruzado anterior (LCA) para mejorar el potencial biológico en pacientes con inmadurez esquelética. Materiales y Métodos: Se detalla el procedimiento quirúrgico en un varón de 8 años (Tanner I), piloto de motocross competitivo. El paso distintivo consiste en realizar, con una rasuradora para artroscopia, un ojal oblicuo en la región superolateral del remanente para el pasaje del injerto de banda iliotibial, de modo que el tejido remanente actúe como soporte biológico y guía del neoligamento. Resultados: A los 12 meses de seguimiento, el paciente tenía una estabilidad clínica completa (pruebas de Lachman y del pivote negativas), sin dismetrías ni alteraciones angulares en las radiografías. Se reintegró, con éxito, a la competición de alto impacto (motocross), la recuperación propioceptiva fue notable y el rango de movilidad, completo. Conclusiones: Esta modificación técnica combina la seguridad mecánica de la reconstrucción extrafisaria con el aporte biológico potencial de la preservación del remanente. En este reporte de un único caso, la técnica resultó ser una alternativa segura; no obstante, se requieren estudios de mayor nivel de evidencia para confirmar sus ventajas comparativas en términos de ligamentización y propiocepción.

Palabras clave: Ligamento cruzado anterior; pediatría; técnica de Micheli-Kocher; preservación del remanente; banda iliotibial.

Nivel de Evidencia: IV

 

INTRODUCTION

Managing anterior cruciate ligament (ACL) tears in children requires a careful balance between restoring joint stability and protecting the physes. In prepubescent patients with substantial skeletal immaturity (Tanner stages I and II), traditional transphyseal techniques carry a documented risk of growth arrest and angular deformity.1

To address this challenge, Kocher, Garg, and Micheli described a combined intra- and extra-articular, physeal-sparing reconstruction technique using an iliotibial band (ITB) autograft, deliberately avoiding bone tunnels that cross the femoral or tibial physes.1 The technique has demonstrated long-term safety and effectiveness, with excellent rates of return to sport2 and robust fixation owing to the versatility and strength of the ITB.3

However, the standard technique does not routinely preserve the ACL remnant, which has received increasing attention in the recent medical literature for its biological potential. Recent systematic reviews suggest that remnant preservation is superior to the standard technique in terms of revascularization and proprioceptive recovery4 and may provide better clinical and functional outcomes.5

Although several pediatric techniques have been described,6 no previous reports have specifically combined the Micheli–Kocher technique with remnant preservation. The indication for this technique was an anteromedial bundle tear with a mechanically stable posterolateral bundle remnant containing vascularized synovial fibers. Selective debridement of the intercondylar notch was performed to preserve this native tissue.

This technical note describes a surgical modification intended to combine the safety of an extraphyseal approach with the benefits of biological preservation.

 

MATERIALS AND METHODS

This study was approved by the Institutional Ethics Committee. Written informed consent was obtained from the patient’s parents for the procedure and publication of the case report. Anonymity and protection of the patient’s personal data were ensured in accordance with applicable regulations.

 

Positioning and approach

The patient is placed supine, and an examination under anesthesia is performed to confirm the degree of instability. A longitudinal lateral incision approximately 8 cm long is made over the distal ITB and lateral femoral epicondyle, following the principles described for surgical exposure of the ITB.3

 

Graft harvest and preparation

Dissection proceeds through the tissue layers to expose the fascia lata. Two parallel incisions, 15–20 mm apart, are made in the distal ITB and extended proximally beneath the skin to obtain a graft of sufficient length, generally 16–18 cm (Figure 1). It is essential to preserve the distal ITB insertion at Gerdy’s tubercle to maintain its native anatomical attachment. The proximal end of the graft is released, delivered through the wound, and tubularized using high-strength sutures in a Krackow configuration.

 

Arthroscopic phase and remnant management

Standard arthroscopic portals are established. In the original technique described by Kocher and Micheli, the intercondylar notch is debrided to clearly visualize the “over-the-top” position.1 In this modification, debridement is selective. The ACL remnant is preserved, particularly when it retains a robust tibial attachment and vascularized synovial fibers.

 

Graft passage and integration with the remnant

The “over-the-top” passage is prepared by carefully dissecting the posterior capsule and periosteum along the posterior aspect of the lateral femoral condyle, taking care to avoid injury to the perichondral ring. The tubularized graft is passed deep to the lateral collateral ligament and introduced into the joint using the “over-the-top” technique (Figure 2).

 

 

 

 

 

 

 

 

The key step, once the ITB graft is inside the joint, is to pass it through or adjacent to the preserved remnant. An arthroscopic shaver is used to create an oblique opening approximately 7 mm in diameter in the superolateral corner of the ACL remnant, following the orientation of its fibers and preserving as much viable tissue as possible. The ITB graft is then passed through this opening from posterior to anterior. If a size mismatch prevents smooth passage, the opening is gradually enlarged to match the graft diameter as closely as possible, while avoiding excessive resection of the remnant. The native tissue thus envelops the graft, providing biological and mechanical support that guides the orientation of the reconstructed ligament and maximizes tissue–graft contact for revascularization. No additional sutures are needed to secure the remnant to the graft.

 

Tibial fixation

The graft is pulled distally toward the tibia. Extraepiphyseal tibial fixation is achieved by passing the graft beneath the intermeniscal ligament and suturing it to the medial tibial periosteum (Figure 3). Fixation may be reinforced with staples or bone anchors placed distal to the anterior tibial physis, with appropriate tension maintained at 20°–30° of knee flexion.

Finally, full knee extension is checked clinically and arthroscopically to rule out graft impingement or interposition of the remnant within the intercondylar notch.

 

 

 

 

 

RESULTS

We present the case of an 8-year-old boy, a competitive motocross rider, who was skeletally immature (Tanner stage I). He sustained a knee injury, and an ACL tear was confirmed by magnetic resonance imaging (MRI) (Figure 4) and physical examination. Intraoperative assessment confirmed an anteromedial bundle tear with an intact posterolateral bundle and a viable tibial remnant.

 

 

 

 

 

The modified Micheli–Kocher technique with remnant preservation described above was performed. The post-operative protocol included immobilization in a long-leg splint for 6 weeks and progressive weight bearing as tolerated. At the 12-month follow-up, the knee was clinically stable, with negative Lachman and pivot-shift tests and a full range of motion. The patient had returned to his previous competitive level without pain or limitations. Follow-up radiographs showed no limb length discrepancy or angular deformity of the lower limbs. MRI showed a correctly positioned and oriented reconstructed ligament, without a horizontal course (Figure 5).

 

 

 

 

 

DISCUSSION

ACL reconstruction in skeletally immature patients, generally aged 6–13 years, presents unique challenges. The Micheli–Kocher technique remains the procedure of choice because it fully spares the physes.1,2 Our modification aims to add a meaningful biological benefit to this mechanically established procedure.

The main rationale for preserving the remnant lies in the biology of “ligamentization.” The current medical literature suggests that remnant preservation may accelerate cellular repopulation and improve vascularization. Available evidence indicates that it may promote cellular repopulation, revascularization, and biomechanical graft integration.4 In our case, the successful return to motocross indicates good functional recovery. However, the potential benefits in proprioceptive reinnervation and the quality of ligamentization remain hypothetical and were not assessed objectively. In children, whose biological response is greater, maximizing this potential is a logical step. Preserving the tibial remnant may also offer important rehabilitation benefits, as the loss of mechanoreceptors is a major concern in reconstruction and the remnant serves as a source of proprioceptive reinnervation.5

From a biomechanical perspective, although current trends favor anatomical reconstruction,7 the Micheli–Kocher technique prioritizes physeal safety over precise restoration of femoral anatomy. Creating the opening in the superolateral corner gives the remnant an even greater role: it acts as a hammock or natural scaffold, helping the reconstructed ligament follow an orientation closer to that of the native tissue and preventing a horizontal course. This makes soft tissue integration even more critical. The proposed synergy extends beyond biology, as remnant preservation also helps control rotation more effectively than reconstruction alone.5 However, these theoretical benefits must be distinguished from the observed clinical outcomes, which are limited to mechanical stability and range of motion.

This technique requires careful patient selection. As Pascual-Leone et al. emphasize, pediatric surgical techniques must be tailored to each patient’s individual characteristics.6 Not all patients are suitable candidates. Attempting to preserve a fibrotic or insufficient remnant, or one that obstructs visualization, may lead to complications such as cyclops syndrome or extension deficits. As Colombet cautions, surgeons must always weigh the intraoperative risks and benefits of augmentation to avoid compromising joint mechanics.8

In conclusion, this modification of the Micheli–Kocher technique maintains the established safety of extraphyseal reconstruction while preserving the remnant’s biological potential by passing the graft through a superolateral opening. In this single case report, the technique was feasible and safe, although prospective studies with larger samples are needed to determine whether it offers clinical advantages over the conventional technique.

This study has the limitations inherent to a single case report (level V evidence), which prevent generalization of the findings or statistical comparison with the standard technique. The absence of validated functional scores and objective proprioception testing also limits assessment of the actual biological benefit of the technique described.

 

REFERENCES

 

1.     Kocher MS, Garg S, Micheli LJ. Physeal sparing reconstruction of the anterior cruciate ligament in skeletally immature prepubescent children and adolescents. J Bone Joint Surg Am 2005;87(11):2371-9. https://doi.org/10.2106/JBJS.D.02802

2.     Willimon SC, Jones CR, Herzog MM, May KH, Leake MJ, Busch MT. Micheli anterior cruciate ligament reconstruction in skeletally immature youths: A retrospective case series with a mean 3-year follow-up. Am J Sports Med 2015;43(12):2974-81. https://doi.org/10.1177/0363546515608477

3.     Baxter T, Majumdar A, Heyworth BE. Anterior cruciate ligament reconstruction procedures using the iliotibial band autograft. Clin Sports Med 2022;41(4):549-67. https://doi.org/10.1016/j.csm.2022.05.001

4.     Zhang Y, Xiao X, Deng W, Wang J, Gao H, Han J. Is remnant preservation in anterior cruciate ligament reconstruction superior to the standard technique? An overview of systematic reviews. BMC Musculoskelet Disord 2023;24(1):910. https://doi.org/10.1186/s12891-023-07010-0

5.     Hu J, Qu J, Xu D, Zhou J, Lu H. Clinical outcomes of remnant preserving augmentation in anterior cruciate ligament reconstruction: a systematic review. Knee Surg Sports Traumatol Arthrosc 2014;22(9):1976-85. https://doi.org/10.1007/s00167-013-2749-8

6.     Pascual-Leone N, Gross PW, Meza BC, Fabricant PD. Techniques in pediatric anterior cruciate ligament reconstruction. Arthroscopy 2022;38(10):2784-6. https://doi.org/10.1016/j.arthro.2022.08.003

7.     Fox MA, Zsidai B, Dadoo S, Greiner JJ, Musahl V. Anatomic anterior cruciate ligament reconstruction. Arthroscopy 2023;39(9):1968-70. https://doi.org/10.1016/j.arthro.2023.03.004

8.     Colombet P. Editorial Commentary: Anterior cruciate ligament augmentation: A bold, technically demanding surgical technique… but don’t forget to evaluate the benefit-risk ratio! Arthroscopy 2018;34(3):723-5. https://doi.org/10.1016/j.arthro.2017.10.020

 

 

G. Fernández-Staudacher ORCID ID: https://orcid.org/0009-0007-7297-9413

D. Veloz Serrano ORCID ID: https://orcid.org/0000-0003-3350-2157

 

Received on February 19th, 2026. Accepted after evaluation on May 28th, 2026 • Dr. GENARO R. CUCALÓN • gcucalonoyt@gmail.com • https://orcid.org/0000-0003-2551-713X

 

How to cite this article: Cucalón GR, Fernández-Staudacher G, Veloz Serrano D. Modification of the Micheli-Kocher Technique with Anterior Cruciate Ligament Remnant Preservation and Augmentation in Pediatric Patients: A Technical Note. Rev Asoc Argent Ortop Traumatol 2026;91(5):503-509. https://doi.org/10.15417/issn.1852-7434.2026.91.5.2315

 

 

Article Info

Identification: https://doi.org/10.15417/issn.1852-7434.2026.91.5.2315

Published: October, 2026

Conflict of interests: The authors declare no conflicts of interest.

Copyright: © 2026, Revista de la Asociación Argentina de Ortopedia y Traumatología.

License: This article is under Attribution-NonCommertial-ShareAlike 4.0 International Creative Commons License (CC-BY-NC-SA 4.0).