Posterior laxity increases over time after PCL reconstruction
Restoration of posterior tibial translation (PTT) after reconstruction of the posterior cruciate ligament (PCL) is deemed necessary to restore physiological knee kinematics. However, current surgical techniques have failed to show a complete reduction of posterior laxity. It was hypothesized that early postoperative PTT increases over time.
The study comprised of 46 patients (10 female, 36 male; 30 ± 9 years), who underwent PCL reconstruction in a single-surgeon series. Patients were evaluated by bilateral stress radiographs in a prospective manner preoperatively; at 3, 6, 12 and 24 months; and at a final follow-up (FFU) of at least 5 years. Covariants included age, gender, BMI, tibial slope (TS) and the number of operated ligaments. Two blinded observers reviewed all radiographs, evaluating the TS and the posterior tibial translation.
All patients were evaluated at a mean final follow-up of 102 (range 65–187) months. Mean side-to-side difference of the PTT significantly improved from preoperative to 3-month postoperative values (10.9 ± 3.1 vs. 3.6 ± 3.8 mm; P < 0.0001). The PTT increased to 4.6 ± 3.7 mm at 6 months, to 4.8 ± 3.3 mm at 12 months, to 4.8 ± 3.2 mm at 24 months, to 5.4 ± 3.4 mm at FFU. Consequently, there was a significant increase of PTT between 3-month and final follow-up (3.6 ± 3.8 vs. 5.4 ± 3.4 mm; P = 0.02). Flattening of the TS resulted in a significantly higher PTT compared to subjects with a high TS at 24 months and FFU. There was no significant influence by BMI, age, gender and the number of operated ligaments.
Early results after PCL reconstruction seem promising as posterior tibial translation is significantly improved. However, there is a significant increase in PTT from early postoperative values to the final follow-up of at least 5 years. This is particularly notable in patients with flattening of the TS. As a consequence, surgeons and patients need to be aware that initial posterior stability should not be equated with the final outcome.
Level of evidence
Cohort study, Level III.
KeywordsPosterior cruciate ligament Ligament reconstruction Posterior tibial translation Tibial slope Timely increment
We would like to show our gratitude to Kevin C. Wang (Northwestern University Feinberg School of Medicine Chicago, IL, USA) for his constructive criticism and for his correction of the manuscript, which led to a significant improvement of the study.
All authors have seen and approved submission of the manuscript, and have taken due care to ensure the integrity of the work. CG: Data collection, Writing and editing the manuscript. TMJ: Data analysis, Revising the manuscript. IS: Data collection, Writing the manuscript. AW: Co-ordinated the study, Data collection, Writing the manuscript.
All authors declare that they have not received any funding or research Grants in the course of study, research or assembly of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest in the authorship and publication of this contribution. More specifically, none of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), had any financial relationship, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. In addition, all authors declare that they have had no other relationships, or have been engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work.
The ethics committee of Charité-Universitaetsmedizin Berlin approved the current study (EA1/003/16).
Informed consent was obtained from all individual participants included in the study.
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