Sir,
Posterior Cruciate Ligament (PCL) is the most robust ligament of the knee; still the awareness about its injuries and their management had not caught due attention of the orthopedic surgeons, until recently, as compared to its counterpart of Anterior Cruciate Ligament (ACL). The PCL injuries in the past were either not diagnosed or were mostly treated conservatively by wilful neglect. However, after the excellent understanding and success of the management of ACL injuries, the PCL injuries have found the much required attention of the Arthroscopic surgeons across the world, in the recent past. In a detailed review of literature of the past four decades (1979–2018) on the PubMed, we found a healthy and steady increase in the publication of research papers, which have increased from 13 in 1979 to 299 in 2018 (a 23 fold increase), with a significant increase since 1991 (unpublished data). It indicates the popularity and importance given for the PCL injuries in the recent past. Whereas in comparison, the numbers for ACL in a recent literature review [1], we found a 53 fold increase from 26 to 1380 in the last 40 years (Table1; Fig. 1). The total number of publications on ACL, in the last 40 years were 18696 and for PCL were 5025 (a ratio of approx. 187:50). In 1979, the number of ACL publications was twice the number of publications on PCL, but by 2018 the publications on ACL further increased to 4.6 times the number on PCL. We believe that the start of PubMed in 1998, has contributed significantly in increasing number of publications for both ACL and PCL (Table 1; Fig. 2), as the authors could find an excellent platform to showcase their work on these ligaments to the rest of the world and their peers.
Table 1.
Number of publications in PubMed on ACL vs. PCL
| Number of publications | Anterior Cruciate Ligament (ACL) | Posterior Cruciate Ligament (PCL) | ACL/PCL ratio |
|---|---|---|---|
| In the last 40 years (1979–2018) | 18,696 | 5025 | 3.72 |
| Publications before 1979 | 133 | 38 | 3.5 |
| Average per year (1979–2018) | 467 | 93.75 | 4.98 |
| Average after PubMed (1998–2018) | 731.8 | 191.8 | 3.82 |
| Average before PubMed (1979–1997) | 176.2 | 52.5 | 3.36 |
| In 2018 | 1380 | 299 | 4.62 |
| In 1979 | 26 | 13 | 2 |
Fig. 1.
Total number of publications on PCL in PubMed in 1979 and 2018
Fig. 2.
Average number of publications per year (overall, before and after the start of PubMed on ACL and PCL)
We have noted that the articles related to the ACL [1] were reported extensively by the authors and the journals from United States of America (USA), whereas the topic related to the PCL were reported not only by the USA authors but also from the Europe and Japan etc. (Table 2).
Table 2.
Leading publisher in the last 40 years on PubMed on ACL vs. PCL (The approximate numbers are given in brackets)
| Leading publisher | ACL (number) | PCL (number) |
|---|---|---|
| Journal | AJSM (1960) | KSSTA (518) |
| First Author | Shelbourne KD (112) | Fanelli GC (40) |
| Author, in any position | Fu FH (378) | LaPrade RF (71) |
| University | Pittsburgh, USA (585) | Pittsburgh, USA (160) |
| Country | USA (10356) | USA (2640) |
The number of publications on ACL was more than three-fold the number of publications on PCL (even after including those PCL papers related to Arthroplasty). We believe that this could be due to several reasons:
The ACL injuries are much more common than the PCL injuries (The age- and sex-adjusted annual incidence of ACL tears was 68.6 per 100,000 person-years [2], whereas the annual incidence of isolated, complete PCL tears was 1.8 per 100,000 [3])
The ACL injuries produce more dramatic symptomatic instability to the patient, needing immediate attention, as compared to the PCL injuries,
A clinical diagnosis of a PCL tear may be difficult to made initially,
ACL reconstruction is more straightforward to perform than the PCL reconstruction and hence lesser experienced arthroscopic surgeons are hesitant to perform it, and
The majority of arthroscopic surgeons who have been trained before the ‘real explosion’ of the PCL reconstruction (in early-’90s) may not be interested in it due to lack of training and exposure to it.
However, we have noticed a recent healthier trend in the increasing number of publications on the PCL, from across the world.
Author Contributions
Prof Raju Vaishya: concept, data analysis, manuscript writing, manuscript review, final approval. Dr SBS Kambhampati: concept, data collection, data analysis, manuscript writing, manuscript review, final approval. Dr Abhshek Vaish: concept, data analysis, manuscript writing, manuscript review, final approval.
Compliance with Ethical Standards
Conflict of interest
No conflict of interest declared for all authors.
Ethical standard statement
This article does not contain any studies with human or animal subjects performed by any of the authors.
Informed consent
For this type of study informed consent is not required.
Contributor Information
Raju Vaishya, Email: raju.vaishya@gmail.com.
Srinivas B. S. Kambhampati, Email: kbssrinivas@gmail.com
Abhishek Vaish, Email: drabhishekvaish@gmail.com.
References
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