The aim of an anterior cruciate ligament (ACL) reconstruction is to regain functional stability of the knee following ACL injury, ideally allowing patients to return to their pre-injury level of activity. The purpose of this study was to assess clinical, functional and patient-reported outcomes following primary ACL reconstruction with hamstring autograft.

A prospective case-series design (n=1610) was used to gather data on post-operative ACL graft laxity, functional testing performance and scores on the ACL quality of life (ACL-QOL) questionnaire. Demographic data were collected for all patients. Post-operative ACL laxity assessment using the Lachman and Pivot-shift tests was completed independently on each patient by a physiotherapist and an orthopaedic surgeon at the 6-, 12- and 24-months post-operative appointments. A battery of functional tests was also assessed including single leg Bosu balance, and 4 single-leg hop tests. The hop tests provided a comparative assessment of limb-to-limb function. Patients completed the ACL-QOL at all time points. The degree and frequency of post-operative laxity was calculated. A Spearman's rank correlation matrix was undertaken to assess for relationships between post-operative laxity, functional test performance, and the ACL-QOL scores. A linear regression model was used to assess for relationships between the ACL-QOL scores, as well as the functional testing results, and patient demographic factors.

ACLR patients were 55% male, with a mean age of 29.7 years (SD=10.4), mean BMI of 25 (SD=3.9), and mean Beighton score of 3.3 (SD=2.5). At clinical assessment 2-years post-operatively, 20.6% of patients demonstrated a positive Lachman test and 7.7% of patients demonstrated a positive Pivot-shift test. The mean ACL-QOL score was 28.6/100 (SD=13.4) pre-operatively, 58.2/100 (SD=17.6) at 6-months, 71.8/100 (SD=18.1) at 12-months, and 77.4/100 (SD=19.2) at 24-months post-operative. Functional tests assessing operative to non-operative limb performance demonstrated that patients were continuing to improve up to the 24-month mark, with limb symmetry indices ranging from 96.6–103.1 for the single-leg hop tests. Spearman's correlation coefficient demonstrated a significant relationship between the presence of ACL graft laxity and ACL-QOL score at 12- and 24-months post-operative (p < 0 .05). Functional performance on the single leg balance and single-leg hop tests demonstrated significant correlations to the 6-, 12- and 24-month ACL-QOL scores (p < 0 .05). There was no statistically significant correlation between the functional testing results and the presence of ACL graft laxity.

This study demonstrated that up to 20.6% of patients had clinically measurable graft laxity 2-years after ACLR. In this cohort, patients with graft laxity demonstrated lower ACL-QOL scores, but did not demonstrate lower functional testing performance. Patient-reported ACL-QOL scores improved significantly at each time point following ACLR, and functional performance continued to improve up to 2-years after surgery. The ACL-QOL score was strongly correlated to the patient's ability to perform single-limb functional tests, indicating that the ACL-QOL score accurately predicted level of function.

The aim of an anterior cruciate ligament (ACL) reconstruction is to regain functional stability of the knee following ACL injury, ideally allowing patients to return to their pre-injury level of activity. The purpose of this study was to assess clinical, functional and patient-centered outcomes a minimum of 1-year following ACL reconstruction. This study assessed for relationships between post-operative ACL graft laxity, functional testing performance, and scores on the ACL Quality of Life (ACL-QOL) questionnaire.

A prospective cohort study design (n = 1938) was used to gather data on clinical laxity, functional performance and quality of life outcomes. Post-operative ACL laxity assessment using the Lachman and Pivot-shift tests was completed independently on each patient by a physiotherapist and an orthopaedic surgeon at a minimum of 12-months post-operatively. A battery of functional tests was performed including single leg balance, single leg landing, 4 single-leg hop tests, and tuck jumps. The hop tests provided a comparative assessment of limb-to-limb function including a single hop for distance, a 6m timed hop, a triple hop for distance, and a triple crossover hop. Patients com¬pleted the ACL-QOL at the 12-month and 24-month post-operative appointments. Descriptive and demographic data were collected for all patients. The degree and frequency of post-operative laxity was calculated. A Pearson r correlation coefficient was employed to determine the relationship between the presence of post-operative laxity and the ACL-QOL scores, between the battery of functional tests and the ACL-QOL scores, as well as between the functional tests and the laxity assessments.

Data was gathered for 1512/1938 patients (78%). At clinical assessment a minimum of 1-year post-operatively, 13.2% of patients demonstrated a positive Lachman and/or Pivot-shift test. The mean ACL-QOL score for patients with no ACL laxity was 80.8/100, for patients with a positive Lachman or Pivot-shift test the mean score was 72.3/100, and for patients with both positive Lachman and Pivot-shift tests the score was 66.9/100. Pearson r correlation coefficient demonstrated a significant relationship between the presence of ACL graft laxity and ACL-QOL score (p < 0.05). Statistically significant correlations were evident between all of the operative limb single-leg hop tests and the post-operative ACL-QOL scores (p < 0.05). Statistically significant correlations were evident between the operative limb triple-hop tests and presence of ACL graft laxity (p < 0.05).

Patients with clinically measurable ACL graft laxity demonstrate lower ACL-QOL scores as well as lower performance on a battery of functional tests. The disease-specific outcome measure was strongly correlated to the patient's ability to perform single-limb functional tests, indicating that the ACL-QOL score accurately predicted level of function.