Aim The objective of this study was to determine the functional impact of a distension of a ACL surgery, measured by a tool of quantification of the laxity called the “GnRb” and associated with the questionnaire IKDC.

Methods Patients sent to the medical department for an assessment after surgery and after reeducation of a ACL reconstruction between M4 and M12.The assessment contained an evaluation of the laximetry by the tool of quantification GnRb and a isokinetic assessment between January, 2013 and December, 2014. We selected only the patients whose difference of slope in the GnRb was upper to 5, corresponding of 5 to 10 in a partial ACL lesion and in a total ACL rupture beyond 10 when we used it for the clinical diagnose of ACL lesion. We followed them to estimate the functional impact of this distension and the incidence of the recurrence of ACL rupture in this population. The evaluation of the functional items of the IKDC was made by phone contact.

Results On 250 patients sent during this period, 25 (only 10%) presented a difference of slope upper to 5 [5.3 – 12.7] and 15 of them answered the questionnaire IKDC. The evaluation GnRb took place in the 8th month after surgery on average [4–22]. None wound was reported in the weeks preceding the measure and being able to modify the tension of ACL. The questionnaire IKDC was realised by phone between 18 and 36 months after surgery. All the patients benefited from a specific reeducation in ligamentoplasty by free patella transplant (4), transplanting in DIDT (11) and extra articular surgery (1). The instructions of resumption were respected and the patients got back on average 88.4% of their previous state according to the evaluation by IKDC. On 15 answering, was revealed a counter-lateral partial break, a counter-lateral total break having justified a ligamentoplasty; only one recurrence was found and represent 6.6% of the population. 7 patients estimated to have recovered an optimal functional state comparable to the preoperative state with a upper score IKDC of 90%. For the others, apprehension and the fear of the recurrence was two main brakes to return to sport.

The measures were realised on average in 8 months post-operative, whatever is the surgical technique with different ligamentization process and consolidation between a plastic surgery with DIDT or free patella transplant. The lack of standardisation of the deadline of the evaluation does not allow us to move forward the absence of correlation between the ligamentary distension and the functional impact or the recurrence.

Conclusion The ligamentary distension, measured by GnRb, does not determine exclusively the future of the knee. The threshold of laxity must be able to determine the follow-up of the patients in reeducation. The follow-up of this troop can bring us answers so that this tool diagnosis has its place in the active follow-up of a ACL reconstruction and is a precious help to the physiotherapist in the approach of protection of these surgeries.