Anterior cruciate ligament (ACL) rupture with associated meniscal pathology commonly occurs in a young, active population. Preserving a greater proportion of the meniscus may improve long-term outcomes by maintaining shock absorption and knee stability. However, meniscal repair procedures involve longer healing and rehabilitation than meniscal debridement, which could affect return to work and activity. The purpose of this study was to examine the functional outcomes and quality of life scores through two years in patients undergoing ACL reconstruction (ACL-R) who had meniscal repair, meniscal debridement, or no meniscal damage at the time of reconstruction.

Data for 1814 skeletally mature patients with isolated primary ACL-R was prospectively collected at a single centre from January 2010 to December 2015. Functional testing of operative to non-operative limb performance was completed at one- and two-years following surgery and included single-leg balance, single-leg hop for distance, timed six-meter hop, triple-hop for distance, and triple cross-over hop for distance. ACL-Quality-of-life questionnaires (ACL-QoL) were completed pre-operatively and at 1- and 2-years post-operatively. Descriptive statistics were completed for patient demographics and intra-operative pathology. Unpaired t-tests using 95% confidence intervals were conducted to compare groups.

The patient cohort was 45% female, with a mean age of 31 years (SD 11, range 14–66). Meniscal injury was detected in 1229/1814 knees (67.8%). There were 729 debridements and 538 repairs performed. Graft choice was hamstring autograft in 85.8% of cases, bone-patellar-tendon-bone autograft in 2.5%, allograft in 10.1% and other graft types in 1.5%. Pre-operative ACL-QoL scores were 29 and 28.5 for knees without and with meniscal damage, respectively (p>0.05).

Of 1814 patients, 1269 (69.9%) completed the ACL-QoL at the two-year appointment, and 1225 (67.5%) completed the functional testing. At two years post-operative, patients with no meniscal damage at surgery demonstrated superior limb symmetry performance on triple-hop for distance compared to patients with meniscal damage (98.4% vs 97.1%, p < 0 .05, CI 0.1–2.5%). No other functional testing parameters showed statistical significance. There was no difference in functional outcome between patients undergoing an isolated meniscal repair versus debridement at one- or two-years. ACL-QoL scores were statistically significantly higher at one- and two-years post-operative for patients without meniscal damage (1-year: 73 vs 70.2, p < 0 .05, CI 0.51–5.1, 2-years: 79.2 vs 76.1, p < 0 .05, CI 0.79–5.4). ACL-QoL scores were minimally higher for isolated meniscal debridement compared to isolated meniscal repair at both time points (1-year: 71.4 vs 68, p < 0 .05, CI 0.4–6.4, 2-years: 78.3 vs 74, p < 0 .05, CI 1.3–7.3).

Functional outcomes do not differ at one or two years post-operatively for patients undergoing meniscal repair versus debridement concomitant with ACL-R. Quality of life scores were statistically significantly higher for the patients with no meniscal pathology at both one- and two-years post-operative. ACL-QoL scores were also statistically significantly different for the meniscal repair and debridement groups however these differences are unlikely to be clinically significant. Extended follow-up is needed to determine if the differences detected in ACL-QoL scores are sustained over time, as well as the long-term role of meniscal injury on functional outcomes.

Knee laxity following anterior cruciate ligament (ACL) injury is a complex phenomenon influenced by various biomechanical and anatomical factors. The contribution of soft tissue injuries – such as ligaments, menisci, and capsule – has been previously defined, but less is known about the effects of bony morphology. (Tanaka et al, KSSTA 2012) The pivot shift test is frequently employed in the clinical setting to assess the combined rotational and translational laxity of the ACL deficient knee. In order to standardise the maneuver and allow for reproducible interpretation, the quantitative pivot shift test was developed. (Hoshino et al, KSSTA 2013) The aim of this study is to employ the quantitative pivot shift test to determine the effects of bone morphology as determined by magnetic resonance imaging (MRI) on rotatory laxity of the ACL deficient knee.

Fifty-three ACL injured patients scheduled for surgical reconstruction (36 males and 17 females; 26±10 years) were prospectively enrolled in the study. Preoperative magnetic resonance imaging (MRI) scans were reviewed by two blinded observers and the following parameters were measured: medial and lateral tibial slope, tibial plateau width, femoral condyle width, bicondylar width, and notch width. (Musahl et al. KSSTA 2012). Preoperatively and under anaesthesia, a quantitative pivot shift test was performed on each patient by a single experienced examiner. An image analysis technique was used to quantify the lateral compartment translation during the maneuver. Subjects were classified as “high laxity” or “low laxity” based upon the median value of lateral compartment translation. (Hoshino et al. KSSTA 2012) Independent t-tests and univariate logistic regression were used to investigate the relationship between the pivot shift grade and various features of bone morphology. Statistical significance was set at p<0.05.

A high inter-rater reliability was observed in all MRI measurements of bone morphology (ICC=0.72–0.88). The median lateral compartment translation during quantitative pivot shift testing was 2.8mm. Twenty-nine subjects were classified as “low laxity” (2.8mm). The lateral tibial plateau slope was significantly increased in “high laxity” patients (9.3+/−3.4mm versus 6.1+/−3.7mm; p<0.05). No other significant difference in bone morphology was observed between the groups.

This study employed an objective assessment tool – the quantitative pivot shift test – to assess the contribution of various features of bone morphology to rotatory laxity in the ACL deficient knee. Increased lateral tibial plateau slope was shown to be a significant independent predictor of high laxity. These findings could help guide treatment strategies in patients with high grade rotatory laxity. Further research into the role of tibial osteotomies in this sub-group is warranted.