Hip and Knee Alignment After ACL Injury and Osteoarthritis Risk
Author Information
Author(s): Henrik Nilsson, Martin Englund, Richard Frobell, L. Stefan Lohmander, André Struglics, Per Swärd
Primary Institution: Lund University
Hypothesis
A higher neck‐shaft angle (NSA) and valgus alignment of the ACL injured knee would be associated with the development of lateral tibiofemoral osteoarthritis, whereas a smaller NSA and varus alignment would be associated with medial tibiofemoral osteoarthritis.
Conclusion
A smaller NSA and HKA angle of the ACL injured leg 2 years after the injury was associated with medial tibiofemoral radiographic osteoarthritis 3 years later.
Supporting Evidence
- Patients with medial tibiofemoral OA had smaller NSA and HKA angles at the 2-year follow-up.
- No association was found between alignment and lateral tibiofemoral or patellofemoral OA.
- The study included 115 patients with a mean age of 26.2 years.
Takeaway
If your knee and hip are more bent inward after an ACL injury, you might get arthritis in your knee later on.
Methodology
An exploratory analysis was conducted in the KANON trial with 115 subjects assessed at 2 years and followed up with radiographs at 5 years.
Potential Biases
Factors such as meniscal pathology and cartilage loss may bias findings related to knee alignment.
Limitations
The low prevalence of compartment-specific OA suggests a high risk of statistical type II errors.
Participant Demographics
Mean age of 26.2 years, 26% women, mean BMI of 24.1.
Statistical Information
P-Value
0.02 for HKA, <0.01 for NSA
Confidence Interval
HKA: 95% CI −4.2° to −0.4°; NSA: 95% CI −7.9° to −1.1°
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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