In a population-based epidemiological study published in the July 6, 2016 Journal of Bone & Joint Surgery, Tibor et al. found that from 2007 to 2014:
- Many ACL-reconstruction surgeons changed from a transtibial approach to either an anteromedial portal or lateral approach for femoral-tunnel drilling.
- Most did not substantially change the types of grafts they used.
- Many eschewed first-generation bioabsorbable implants in favor of biocomposite fixation devices.
The authors found no change in cumulative revision rates during the study period.
Tibor et al. analyzed information from 21,686 primary ACL reconstructions housed in a Kaiser Permanente registry that collected data from surgeries performed in 33 hospitals by 246 surgeons in urban, rural, and suburban settings in three Western US states. This wide-ranging data set, the authors say, “increases the generalizability of our findings to other community-based surgeons.”
The authors admit, however, that the epidemiological nature of the study “offers only limited insight into associated outcomes,” and they were unable to analyze cost trends because the registry does not capture cost data.
The rate of graft failure following anatomic ACL reconstruction has been reported to be as high as 13%, nearly double the reported failure rate of transtibial reconstructions. The majority of anatomic graft failures occur six to nine months after surgery, when patients commonly return to full sports activity. Findings from a cadaver study by Araujo et al. in the November 4, 2015 edition of The Journal of Bone & Joint Surgery may help explain these phenomena.
The authors used a robotic system to measure in situ forces on 12 native cadaver ACLs and on three different reconstructions, one representing the anatomic approach and two reconstructions approximating traditional transtibial approaches. They measured forces on the grafts during anterior tibial loading and simulated pivot-shift loading.
Araujo et al. hypothesized that an anatomically positioned graft would experience increased in situ forces relative to transtibial positioning, and that is what the study revealed during knee flexion angles of 0°, 15°, and 30°. At 45°, 60°, and 90° of flexion, the transtibially positioned grafts experienced higher in situ loading forces than the anatomic ones.
While this cadaveric study is not the definitive word on this matter, with the high graft forces on the anatomic reconstructions, the authors suggest that “rehabilitation and return to sports progression may need to be modified to protect an anatomically placed graft after ACL reconstruction.”