What did the study look at?
The anterior cruciate ligament (ACL) protects the knee against excessive forward shift and inward rotation. The authors note that re-rupture after ACL reconstruction has been reported in up to 11% of patients, and that one risk factor is a steep backward slope of the top of the shin bone (posterior tibial slope greater than 12°).
An anterior closing wedge osteotomy removes a wedge of bone from the front of the shin bone to reduce this slope. The review aimed to summarise current evidence on its indications, techniques and outcomes, and to describe the authors' preferred technique during a staged ACL revision.
How was it done?
This is a review: the authors did not collect new patient data but summarised biomechanical studies, technique papers, case series and case reports on the topic. They also describe their own approach to planning, surgical technique and post-operative care.
What did it find?
- Indications: the most commonly reported indication is revision ACL surgery in knees with a posterior slope of 12° or more. For a first ACL injury, a slope above 15° has been reported.
- Contraindications: the review lists marked malalignment (more than 10° of hyperextension or bow-leggedness), posterior cruciate ligament deficiency and advanced (grade IV) osteoarthritis; a body mass index above 30 and smoking more than 20 cigarettes a day are reported as relative contraindications.
- Biomechanics: in a cadaveric study, graft force fell by up to 33% of axial load after a 10° correction.
- Technique: the osteotomy can be made at, below or above the bony prominence of the shin bone (tibial tubercle). The goal is a slope below 10°, around 6–8°, and overcorrection should be avoided.
- Clinical results: only small studies are available. In a five-patient series, at a mean of 31.6 months the side-to-side difference in forward laxity fell from 10.4 mm to 2.8 mm and 80% returned to their pre-injury sport level. In another study of nine patients with at least two years' follow-up, no graft ruptures or recurrent instability were reported.
- Complications: reported risks include incorrect correction, unwanted fractures, injury to the artery behind the knee (popliteal artery), non-union and infection.
The authors' conclusion
The authors conclude that, in ACL-deficient patients with a steep posterior slope, early studies suggest this osteotomy improves knee stability and reduces graft strain. Long-term studies and prospective comparisons of ACL reconstruction with and without the osteotomy are still needed.
Limitations
The authors state that clinical outcome data for this procedure remain largely limited and that current results come from low-level case series and case reports.
Reference
Vadhera AS, Knapik DM, Gürsoy S, Farivar D, Perry AK, Cole BJ, Chahla J. 2021. Current Concepts in Anterior Tibial Closing Wedge Osteotomies for Anterior Cruciate Ligament Deficient Knees. Current Reviews in Musculoskeletal Medicine. 14(6):485–492. A correction to an author's name was published in 2022 (DOI: 10.1007/s12178-022-09750-x).
DOI: 10.1007/s12178-021-09729-0
Free full text: PubMed Central PMC8733136
This article summarises a published scientific paper for general information; it does not replace an examination or a personal medical assessment. Please consult your doctor about your symptoms.
