Peri-graft bone mass and connectivity as predictors for the strength of tendon-to-bone attachment after anterior cruciate ligament reconstruction

Chunyi Wen, Ling Qin, Kwong Man Lee, Kai Ming Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)


The present study was designed to compare peri-graft bone mass and microarchitecture with tendon-to-bone (T-B) attachment strength after anterior cruciate ligament (ACL) reconstruction in a rabbit model. Surgical reconstruction using digital extensor tendon in bone tunnel was performed on 58 rabbits. Forty-two of the 58 rabbits were sacrificed at week 0, 2, 6 and 12 after operation respectively. The femur-graft-tibia complexes were harvested for pQCT and micro-CT examination to characterize the spatiotemporal changes of peri-graft bone in T-B healing in conjunction with histological examination. The remaining 16 rabbits were euthanized at week 6 and 12 postoperatively (i.e. 8 rabbits for each time point) for pull-out test after micro-CT examination to investigate the relationship between the T-B attachment strength and peri-graft bone mass/microarchitecture. Peri-graft BMD, BV/TV and connectivity was significantly lower at week 6 than those at time zero although there were no significant changes detected in the first 2 postoperative weeks. In addition, peri-graft bone mass and connectivity was significantly lower on the tibial side than those on the femoral side; and osteoclasts accumulated on the surface of peri-graft bone. Grafted tendon was prone to be pulled out from the tibial tunnel with bone attachment; the weakest point of the complexes shifted from the healing interface at time zero to peri-graft bone at week 6 after operation. With reverse of peri-graft bone at week 12 postoperatively, the weakest point shifted to the intra-osseous tendinous portion. The stiffness of T-B attachment correlated with peri-graft BV/TV (r2= 0.68, p = 0.001) and connectivity (r2= 0.47, p = 0.013) at week 6 after operation. T-B healing was a highly dynamic process of emergence and maintenance of peri-graft bone. T-B attachment strength was in relation to peri-graft bone mass and connectivity after ACL reconstruction. The measurement of peri-graft bone should be useful to monitor the quality of T-B healing and guide the postoperative rehabilitation.
Original languageEnglish
Pages (from-to)545-552
Number of pages8
Issue number3
Publication statusPublished - 1 Sep 2009
Externally publishedYes


  • Anterior cruciate ligament (ACL) reconstruction
  • Bone mass
  • Micro-computed tomography (micro-CT)
  • Microarchitecture
  • Peripheral quantitative computed tomography (pQCT)

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Histology
  • Physiology

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