Slope reducing osteotomy useful option for revision ACL reconstruction if posterior tibial slope more than 12degrees

While the literature suggests a correlation between posterior tibial slope (PTS) and sagittal stability of the knee, there is a lack of consensus relating to how to measure the slope, what a normal slope value would be, and which critical values should guide extra surgical treatment.

Vipul Mandalia et al performed a systematic literature review looking at the posterior tibial slope and cruciate ligament surgery. The study has been

Electronic searches of MEDLINE (PubMed), CINAHL, Cochrane, Embase, ScienceDirect, and NICE in June 2020 were completed. Inclusion criteria were original studies in peer-reviewed English language journals. A quality assessment of included studies was completed using the Methodological Index for Non-Randomized Studies (MINORS) Criteria.

Key findings of the study:

• Two-hundred and twenty-one papers were identified; following exclusions 34 papers were included for data collection.

• The mean MINORS score was 13.8 for non-comparative studies and 20.4 for comparative studies, both indicating fair to good quality studies.

• Thirty of the papers included were level 3evidence and one paper was level 2 evidence.

• A large variation in the posterior tibial slope measurement technique was identified, resulting in a wide range of values reported.

• A significant variation in slope value also existed between different races, ages and genders.

“To calculate “normal” values for PTS a standardised methodology must exist. Typically short lateral radiographs and MRI scans are the most frequently used imaging modalities for cruciate surgery. Therefore, an ideal method of measuring PTS should consider this and be reliably transferable between the two. The proximal tibial axis has been shown to be the closest surrogate to the true mechanical axis and should, therefore, be adopted for regular use, ideally with two central reference points at 5 and 15 cm from the joint line. Based on the available literature normal ranges of 6-12º using the proximal tibia axis at 5 and 15 cms below the joint” the authors commented.

Cautiously, the authors suggest a normal range of 6-12º, using the proximal tibial axis at 5 and 15 cms below the joint. The authors suggest 12º as a cut-off value for slope-reducing osteotomy as an adjunct to revision ligament reconstruction.

For details of steps please refer to:

Posterior Tibial Slope in Anterior Cruciate Ligament Surgery: A Systematic Review

Vipul Mandalia, Morgan Bayley

Indian Journal of Orthopaedics (2023) 57:1376–1386

https://doi.org/10.1007/s43465-023-00947-x