Letter to the Editor: Anterior knee pain in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft and autologous bone grafting

Abstract

Bone-patellar tendon-bone anterior cruciate ligament reconstruction is associated with donor-site morbidity, particularly anterior knee pain (AKP). I read with great interest the recent article by Byravamoni Venugopal et al that evaluated autologous bone grafting of harvest-site defects as a strategy to reduce AKP. While the technique is biologically appealing, several methodological limitations warrant consideration. The exclusive use of the Kujala Anterior Knee Pain Score as the primary outcome may underestimate pain-specific morbidity due to its subjective nature and ceiling effect, evident from score clustering in the higher range. The retrospective design with telephonic follow-up introduces recall bias, particularly for activity.

Key Words: Knee; Anterior knee pain; Anterior cruciate ligament; Bone patellar tendon bone; Autograft

Core Tip: We read with interest the article by Byravamoni Venugopal et al addressing anterior knee pain following bone-patellar tendon-bone anterior cruciate ligament reconstruction using autologous bone grafting, an important issue related to donor-site morbidity. While the technique is innovative and cost-effective, several methodological limitations may affect interpretation of the findings. The exclusive reliance on the Kujala score, which is subjective and prone to ceiling effects, limits its ability to accurately quantify anterior knee pain severity. The retrospective design with telephonic follow-up further increases the risk of recall bias, particularly for activity-specific pain such as kneeling or squatting. Additionally, the lack of detailed reporting on associated intra-articular injuries introduces potential confounding, as these pathologies can independently influence postoperative pain and function. Finally, the absence of a control group restricts causal inference regarding the true benefit of donor-site bone grafting. Prospective controlled studies using pain-specific outcome measures are needed to confirm the clinical efficacy of this technique.

TO THE EDITOR

We read with great interest the article titled “Anterior knee pain in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft and autologous bone grafting” by Byravamoni Venugopal et al[1], published in the World Journal of Orthopaedics. The authors should be commended for addressing donor-site morbidity following bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction and for evaluating a cost-effective technique aimed at reducing anterior knee pain (AKP), a well-recognized concern after BPTB graft harvest[1,2].

However, several methodological concerns merit discussion and may limit the interpretation of the study’s conclusions. First, the exclusive use of the Kujala Anterior Knee Pain Score as the primary outcome measure is debatable. Although validated for patellofemoral disorders, the Kujala score is a subjective functional assessment and may underestimate pain-specific morbidity in postoperative ACL populations. Importantly, it is known to demonstrate a ceiling effect, which is evident in this study where most patients scored above 90, with over half scoring between 95 and 99. Such clustering limits discriminatory ability and is particularly relevant in a study primarily evaluating the incidence and severity of AKP.

Second, the retrospective study design with telephonic follow-up introduces a substantial risk of recall bias, especially when assessing subjective pain outcomes. Anterior knee pain following BPTB harvest is frequently activity-specific, particularly during kneeling, squatting, or stair climbing, and may not be reliably captured retrospectively using a global functional score alone. The inclusion of a pain-specific assessment tool, such as a visual analog scale for anterior knee pain during defined activities, would have strengthened the outcome evaluation.

Third, the study does not clearly report the incidence or management of associated intra-articular pathologies, including meniscal injuries or chondral lesions. These conditions are common in ACL-deficient knees and can independently influence postoperative pain and functional outcomes, thereby acting as important confounding variables when interpreting Kujala scores.

Finally, the absence of a control group significantly limits causal inference. Without direct comparison with patients undergoing conventional BPTB ACL reconstruction without donor-site bone grafting, it is difficult to attribute the reported low incidence of AKP solely to the proposed technique. Comparisons with historical cohorts cannot adequately account for variations in patient demographics, rehabilitation protocols, surgical technique, or outcome assessment methods.

CONCLUSION

While the described technique is innovative and biologically appealing, future prospective controlled studies incorporating pain-specific outcome measures and detailed reporting of associated intra-articular injuries are required to validate its true clinical benefit.