Letter to the Editor: Surgical refinements and autologous bone grafting to reduce donor-site morbidity in bone-patellar tendon-bone anterior cruciate ligament-reconstruction

Abstract

Anterior knee pain is a well-recongized, multifactorial issue after anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft. We appreciate the comprehensive commentary by Olaran and Garcia-Mansilla on our recently published study “Anterior knee pain in anterior cruciate ligament -reconstruction using bone-patellar tendon -bone graft and autologous bone grafting”. In this reply, we acknowledge the limitations of our retrospective, single-center study and emphasize the need for larger prospective randomized trials. We also clarify key technical aspects of our approach, including meticulous graft harvest, autologous bone grafting of patellar and tibial donor-site defects using cancellous bone obtained during tunnel drilling and avoidance of soft-tissue and cartilage injury. These refinements have helped in reduction of donor-site morbidity and anterior knee pain after bone-patellar tendon-bone anterior cruciate ligament-reconstruction in our patient cohort. However, these descriptive findings in a retrospective study are hypothesis-generating and cannot establish definitive preventive efficacy. Prospective randomized trials are required to evaluate the independent impact of these surgical refinements on donor-site morbidity.

Key Words: Anterior cruciate ligament reconstruction; Bone-patellar tendon-bone autograft; Anterior knee pain; Donor-site morbidity; Bone grafting

Core Tip: While bone-patellar tendon-bone autografts provide excellent stability in anterior cruciate ligament reconstruction, donor-site morbidity and anterior knee pain remain prevalent. In this reply we outlined a dual protective strategy to overcome these challenges, we performed meticulous handling of the soft tissues using oblique incisions and mallet-free osteotomes to protect both the nerves and cartilage with anatomical autologous bone grafting using tunnel-drilling debris, anterior knee pain shifts from an inevitable complication to an avoidable risk but a large-scale prospective studies are necessary to make it a preventable risk.

TO THE EDITOR

We appreciate the comprehensive commentary by Olaran and Garcia-Mansilla[1] on our recently published study “Anterior knee pain in anterior cruciate ligament -reconstruction using bone-patellar tendon -bone graft and autologous bone grafting”[2]. The primary purpose of this reply is to explicitly address the specific issues raised by the commentators, categorized under three core academic points: Study limitations, graft-volume adequacy, and surgical refinements.

STUDY LIMITATIONS

The commentators correctly identified the principal limitation of our study: Its retrospective, single-center design with a small sample size of 24 patients, and the absence of a concurrent control group. We acknowledge these limitations. Because anterior knee pain is highly multifactorial and potentially influenced by postoperative rehabilitation protocols, baseline physiological symptoms, graft selection, and unmeasured surgical variables, our descriptive data cannot establish a definitive causal link between bone grafting and pain reduction We also concur that prospective, multicenter, randomized controlled trials, involving patient-reported outcome measures, radiographic follow-up, and comparative control group including ungrafted bone-patellar tendon-bone autograft (BPTB) and hamstring tendon autograft groups represent the natural and necessary next step to validate these findings.

EVALUATION OF GRAFT-VOLUME ADEQUACY

We appreciate the technically important point regarding the adequacy of bone volume harvested from the tibial and femoral tunnels. In our study[2], tunnel drilling during standard BPTB ACL reconstruction usually yielded a consistent and sufficient volume of cancellous bone to achieve satisfactory fill of both the patellar and tibial donor-site defects across the cohort. No additional bone graft was harvested from secondary anatomical locations, such as the proximal tibia donor site as described by Myeroff and Archdeacon[3] The collection and packing methodology followed the pre-specified surgical protocol outlined by Krishna et al[4].

SURGICAL REFINEMENTS

To mitigate potential soft tissue complications our technique utilized an oblique incision instead of a vertical one. This avoided excessive medial retraction of skin flap and any untoward injury to the infrapatellar branch of the saphenous nerve. Doing so also avoided pressure on the skin incision during the act of kneeling and squatting. The deeper dissection was limited over the patellar tendon and the proximal and distal bone ends. A small powered saw blade was used to cut the bone plugs from tibia and patella. A sharp 5 mm wide osteotome was used later to separate the bone plugs. No mallet was used to hammer the osteotome. This avoided any injury to the underlying patellar articular cartilage. The surgical refinements as outlined by Krishna et al[4] were followed for all the patients of the study . At a mean post-operative follow-up of 26.4 months, the published cohort exhibited a mean Kujala score of 95.67 ± 4.01[2]. While this score reflects excellent overall patellofemoral function, the Kujala score is a broad composite metric. Causal or absolute claims regarding the prevention of nerve injury, cartilage damage, or anterior knee pain cannot be validated by an uncontrolled retrospective cohort, and these mechanistic rationales are presented strictly as hypothesis-generating observations.

CONCLUSION

Meticulous graft harvesting that minimizes trauma to surrounding soft tissues and patellar articular cartilage is a vital component of BPTB autograft harvesting. While our surgical protocol is technically feasible and demonstrated highly favorable patellofemoral function within our specific cohort, large-scale prospective comparative validation is necessary to confirm its independent clinical efficacy.