Original Article
Results From the Swedish National Anterior Cruciate Ligament Register

https://doi.org/10.1016/j.arthro.2014.02.036Get rights and content

Purpose

The purpose of the study was to analyze the baseline variables and clinical outcomes for almost 24,000 patients entered into the Swedish National ACL Register between January 2005 and December 2012.

Methods

The register consists of 2 parts: 1 section in which surgeons report baseline and surgical data and 1 section in which patients report the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the EQ-5D score before and 1, 2, and 5 years after surgery.

Results

By December 2012, 23,744 patients had been entered into the surgeons’ part of the register. The female-male ratio in the register is 42:58. The mean age at primary anterior cruciate ligament (ACL) reconstruction was 26 years (SD, 11 years) and 28 years (SD, 9 years) for the female and male patients, respectively. The ACL injury occurred during soccer in 36% of the female patients and 49% of the male patients. In 2012, 95% of the primary ACL reconstructions were performed using hamstring tendon autografts. For patients who had a minimum of 5 years’ follow-up, the revision rate was 3.3% and the contralateral reconstruction rate was 3.8%. On all follow-up occasions up to 5 years, patients who had undergone revision had a significantly (P < .001) poorer outcome than those who had undergone primary unilateral ACL reconstructions in all KOOS and EQ-5D dimensions. On all follow-up occasions, smokers obtained significantly poorer scores than nonsmokers in terms of both the KOOS (P < .008) and the EQ-5D (P < .024).

Conclusions

Soccer is the most common cause of injury in both female and male patients, and patients undergoing revisions fare less well than those undergoing primary unilateral ACL reconstructions, as well as bilateral reconstructions. Furthermore, smokers fare less well than nonsmokers. The cumulative risk of an ACL revision or contralateral ACL reconstruction during a 5-year period is approximately 7%. For patients aged younger than 19 years, the cumulative risk is significantly higher.

Level of Evidence

Level II, retrospective prognostic study.

Section snippets

Methods

The main functions of the Swedish ACL Register have previously been reported.2 The register is a general database that uses a Web-based protocol. On the basis of the Swedish social security number, age and gender are registered automatically, and the most recent postal address is continuously updated. The protocol consists of 2 parts: 1 in which the surgeons report baseline and surgical data and 1 with patient-reported outcome measurements (PROMs).

In the surgeon-reported section, factors such

Results

By December 2012, 23,744 patients had been entered into the surgeon-related part of the register; 22,059 unique patients had undergone primary ACL reconstruction, and 1,685 patients had undergone either multiple-ligament reconstructions or revision surgery. Thirty-seven patients had incomplete data, 530 reconstructions were performed on the contralateral knee (i.e., patients had undergone bilateral ACL reconstructions on different occasions), and 1,431 revision reconstructions had been

Discussion

The principal findings in this study were that the revision and contralateral reconstruction rates have decreased compared with a previous report from the Swedish register.2 Patients who had undergone revision or bilateral ACL reconstruction had a poorer outcome than patients who had undergone primary ACL reconstruction. Furthermore, smokers fared less well than nonsmokers. Gender- and graft-related differences were small, and a shift from the use of transfixation devices to cortical fixation

Conclusions

Soccer is the most common cause of injury in both female and male patients, and patients undergoing revisions fare less well than those undergoing primary unilateral ACL reconstructions, as well as bilateral reconstructions. Furthermore, smokers fare less well than nonsmokers. The cumulative risk of an ACL revision or contralateral ACL reconstruction during a 5-year period is approximately 7%. For patients aged younger than 19 years, the cumulative risk is significantly higher.

Acknowledgment

The authors gratefully acknowledge statistician Henrik Magnusson for performing the statistical analysis on the database.

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    The authors report the following potential conflict of interest or source of funding: J. Kartus receives support from Linvatec Sweden for lectures.

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