What did the study look at?
Meniscal root tears are tears close to where the meniscus attaches to the bone. As the authors explain, they can cause the meniscus to slip out of the joint, narrowing of the joint space and cartilage damage. The back (posterior) root of the lateral meniscus lies very close to where the anterior cruciate ligament (ACL) attaches to the shin bone, so it can be damaged when the tibial tunnel is drilled during ACL reconstruction.
The aim of this article is to describe the presentation and treatment of a lateral meniscus posterior root tear caused by a misplaced tunnel in an earlier ACL operation (an iatrogenic injury, meaning one caused by medical treatment), and to raise awareness of this uncommon injury.
How was it done?
This is a case report describing a single patient, who consented to publication.
- A 32-year-old man twisted his knee without contact while playing football and had ACL reconstruction at another centre.
- After surgery he developed instability, swelling and pain, and part of his medial meniscus was removed for a tear (partial meniscectomy).
- Six months later he came to the authors' clinic with ongoing pain and instability. X-rays raised concern that the tibial tunnel was too far back.
- New magnetic resonance imaging (MRI) and computed tomography (CT) showed non-anatomic, posterior tunnels and a suspected tear of the lateral meniscus root.
- Arthroscopy (keyhole examination of the joint) confirmed a complete tear of the lateral meniscus posterior root right next to the graft tunnel. Because the ACL graft was intact and stable, it was not revised.
- The root was repaired by pulling sutures through two tunnels in the shin bone and fixing them (transtibial pull-out technique), and a cartilage defect on the inner side was smoothed.
What did it find?
- After surgery the patient did not bear weight on the operated leg for 4 weeks; physiotherapy began on day 1, and knee bending was limited to 0-90° for the first 2 weeks.
- At 6, 9 and 12 months after surgery, imaging showed an intact meniscal repair with no extrusion, and the patient had no symptoms.
The authors' conclusion
According to the authors, accurate placement of the tibial tunnel during ACL reconstruction is vital to avoid detachment of the meniscal root and its associated problems. They state that this condition should be considered in patients with persistent pain and instability after ACL reconstruction, and recommend MRI in such patients. They add that the best treatment of posterior root tears remains debated and that further research is needed.
Limitations
The original operation was performed at another institution. The authors nevertheless state that they are confident the injury was caused by the surgery, based on MRI, CT and the findings at operation. As with any single-patient case report, the results cannot be generalised.
Reference
Vadhera AS, Lee JS, Singh H, Gürsoy S, Kunze KN, Verma NN, Chahla J. Injury to the Posterior Horn of the Lateral Meniscus from a Misplaced Tibial Tunnel for Anterior Cruciate Ligament Reconstruction: A Case Report. American Journal of Case Reports. 2022;23:e937581. Licence: CC BY-NC-ND 4.0.
DOI: 10.12659/AJCR.937581
Free full text: PubMed Central (PMC9641552)
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.
