This article presents a sophisticated surgical technique for addressing one of the most challenging complications in orthopaedic surgery: recurrent anterior cruciate ligament (ACL) reconstruction failures. The new approach, titled the “Posteromedial Opening-Wedge Tibial Osteotomy”, utilises an innovative, patient-specific cutting guide to correct complex knee deformities that often contribute to these failures.
The Challenge of Complex Deformities
A common reason for the failure of a primary ACL reconstruction is the presence of underlying anatomical issues. Two key factors are a patient’s increased posterior tibial slope (the backward tilt of the shin bone) and metaphyseal varus deformity (a ‘bow-legged’ alignment). If left uncorrected, these deformities place excessive strain on the reconstructed ACL, inevitably leading to re-rupture and chronic instability. Traditional revision techniques can struggle to precisely address these multi-planar deformities, making a standardised and repeatable approach essential.
The Custom Cutting Guide Technique
The authors introduce a refined surgical method that aims to restore the knee’s normal biomechanics. The procedure centres on a patient-specific cutting guide, which is custom-designed based on a pre-operative CT scan to ensure millimetre-perfect accuracy.
The technique involves:
- Posteromedial Opening-Wedge Osteotomy: A precise cut is made in the shin bone from a posteromedial approach. This allows the surgeon to correct both the metaphyseal varus and the excessive posterior tibial slope simultaneously.
- Custom Cutting Guide: The bespoke guide ensures the surgeon can make the osteotomy with extreme precision, a crucial step that is particularly challenging in a revision setting. This guide also facilitates the accurate placement of a new tibial tunnel for the ACL graft.
- Allograft Augmentation: A femoral head allograft (donated bone) is used to fill the wedge created by the osteotomy. This provides structural support for the correction and promotes biological healing.
- Stable Fixation: The osteotomy is secured with a low-profile locking plate, which provides robust fixation and allows for earlier rehabilitation.
By correcting these complex deformities, this technique aims to create a stable environment for the new ACL graft. The use of a custom cutting guide and an allograft provides a reproducible and reliable solution for patients with a history of failed ACL reconstructions, offering a new pathway to long-term knee stability and function.
Professor Wilson’s Comments
“This is a really good paper and was a great idea at the time. It ties in perfectly with the work we’ve been doing with Newclip.
We helped Newclip establish a Scientific Advisory Board (SAB), which includes myself, Prof. Kristian Kley, Prof. Matthieu Ollivier, Dr. Sachin Tapasvi, and Dr. Ronald van Heerwaarden — all close friends and global experts in osteotomy. Together, we’ve been involved from the outset in developing Patient Specific Instrumentation (PSI) for complex osteotomy work.
Over time, this technology has evolved into mainstream surgical guides now used worldwide, particularly for procedures that involve tibial slope correction. This area is becoming increasingly important in knee stability, especially for patients with ACL injuries and a high posterior tibial slope.
To explain it simply: if you imagine the slope of the tibia as a hill viewed from the side, a steep hill allows the femur to slide down more easily, increasing stress on the ACL. By flattening the slope — removing a wedge from the front of the tibia — we can significantly stabilize the knee and reduce strain on the ligament.
This concept is now being considered not only in complex or revision ACL cases, but also in primary ACL reconstructions in high-risk patients with a high slope.
It’s great to see the academic community recognizing the value of this work, and this paper helps reinforce the importance of slope-changing osteotomy as part of modern knee ligament surgery.”
The full research paper is available for an in-depth review of the complete findings, methodology, and analysis:
Sources used in report overview:
- https://pubmed.ncbi.nlm.nih.gov/32874889/
- https://www.jorgechahlamd.com/wp-content/uploads/2019/12/MOW-HTO.pdf
- https://www.researchgate.net/publication/333301295_Adequate_protection_rather_than_knee_flexion_prevents_popliteal_vascular_injury_during_high_tibial_osteotomy_analysis_of_three-dimensional_knee_models_in_relation_to_knee_flexion_and_osteotomy_techniq
