Modifiable factors and their association with self-reported knee function and activity after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

ABSTRACT

Objective

To determine if body mass index (BMI), smoking status, prehabilitation or time to reconstruction are associated with recovery of self-reported knee function and activity after ACL reconstruction (ACLR).

Data Sources

Four electronic databases were systematically searched.

Study Selection

English language articles were included if: (1) participants aged 16–70 years had primary or first revision ACLR with autograft, following complete rupture; and (2) the association between one of four modifiable factors: (1) BMI; (2) smoking; (3) prehabilitation; or (4) time to reconstruction with self-reported knee function and activity, ACL graft rupture or return to sport was evaluated.

Results

Twelve articles (representing 11 studies) were included. Meta-analyses found low-quality evidence of no difference in self-reported knee function (d = −0.07, 95% CI −0.37 to 0.23, I² = 0%) or activity levels (d = 0.11, 95% CI −0.2 to 0.41, I² = 0%) between acute and subacute ACLR. There was no difference in the relative risk of ACL graft rupture with the timing of ACLR (one study). Meta-analysis demonstrated very low-quality evidence that smokers had worse self-reported functional outcomes after ACLR compared to non-smokers (d = −0.58, 95% CI −0.788 to −0.28, I² = 59%). One study suggested an inverse relationship between BMI and knee-related quality of life after ACLR. One RCT suggested prehabilitation may reduce time to return to sport.

Conclusion

Low-quality evidence suggests there is no difference in delaying ACLR and very low-quality evidence suggests smokers have worse self-reported functional outcome after ACLR compared to non-smokers. High-quality RCTs are needed to confirm the relationship between the four modifiable factors studied and ACLR outcome.

KEYWORDS:

• Anterior cruciate ligament (ACL)
• timing
• smoking
• return to sport
• rupture

Acknowledgments

The primary author would like to thank Andrew Hahne, La Trobe University, for assistance in developing the search strategy, and would like to acknowledge Northern Health’s ‘Stepping into Research’ program.

Declaration of Interest

The authors declare no conflict of interest.

Supplemental Material

Supplemental data for this article can be accessed on the publisher’s website