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.

Purpose: This study sought to examine return to sports in athletes younger than 25 following ACL reconstruction with either patellar tendon (PT) or hamstring (HS) autografts using a matched-pairs case-control experimental design.

Method: Twenty-three matched pairs were obtained based on gender (56.5% Female), age (18.3±2.5yrs PT vs.17.6±2.6 HS), and length of follow-up (4.7±2.1yrs PT vs. 4.2±1.6 HS). All patients reported participating in very strenuous (soccer, basketball etc.) or strenuous (skiing, tennis etc.) sporting activity 4–7 times/ week prior to their knee injury. Outcomes other than return to play included the IKDC, SAS, ADLS, SF-36, knee range of motion, laxity, and hop/jump testing.

Results: Most patients in both groups were able to participate in very strenuous or strenuous sporting activity at follow-up [18 (78.3%) PT vs. 19 (82.6%) HS]. However, only 13 (56.5%) of the patellar tendon subjects and 10 (43.5%) of the hamstrings patients were able to return to pre-injury activity levels in terms of frequency and type of sport (p=.63). Hamstrings patients showed higher ADLS (p< .01) and SAS (p< .01) scores and better restoration of extension (p< 0.05).

Conclusion: While autograft and allograft patellar tendon ACL reconstruction exhibit similar clinical outcomes in high-demand individuals, autogenous hamstring grafts may lead to better subjective outcomes in young patients who participate in very strenuous levels of activity. Both graft options only allowed approximately half of the injured athletes to return to their previous level of sporting activity.

Purpose: This study sought to compare clinical outcomes and return to activity in high-demand patients following ACL reconstruction with either autograft or allograft patellar tendon using a matched-pairs case-control experimental design.

Method: Nineteen matched pairs were obtained based on gender (36.8 % female), age (27.9±8.1yrs autograft versus 28.1±9.1 allograft), and length of follow-up (9.1±2.7yrs autograft versus 10.3±2.6 allograft). All patients reported participating in very strenuous (soccer, basketball etc.) or strenuous (skiing, tennis etc.) sporting activity 4–7 times/ week prior to their knee injury. Patient-reported outcomes included the IKDC Subjective Knee Form, Activities of Daily Living (ADLS) and Sports Activity Scales (SAS) of the Knee Outcome Survey and SF-36. Range of motion, laxity, and functional strength were also assessed.

Results: There were no significant differences in patient-reported or clinical outcome measures. Sixteen (84.2%) subjects undergoing autograft reconstruction and 12 (63.2%) subjects reconstructed with allograft were able to participate in strenuous or very strenuous sporting activity at follow-up (p=.34). Similar percentages of subjects were able to return to their pre-injury level of sports activity [12 (63.2%) autograft vs. 11 (57.9%) allograft; p=1.0]. Fewer subjects undergoing reconstruction with autograft reported instability with very strenuous activity [5 (26.3%) autograft vs. 12 (63.2%) allograft], but this difference was not significant (p=.07).

Conclusion: While autograft and allograft patellar tendon ACL reconstruction exhibit similar clinical outcomes in high-demand individuals, autogenous patellar tendon grafts may be indicated to allow patients to return to very strenuous levels of activity.