Short summary

ACL injuries can be treated surgically (with ACL reconstruction) or non-surgically, and it is critical as early as possible after an injury to indentify what treatment is better for each patient. In this study we want to validate an existing screening tool to identify patients who undergo ACL reconstruction after 3 months rehabilitation and further identify other predictive factors, than included in the existing screening tool, to identify patients who undergo ACL reconstruction.

Rationale

Surgical reconstruction of a ruptured anterior cruciate ligament (ACL) has typically been advised if the patient wishes to return to sport and has been found necessary to prevent additional injuries to other structures in the knee. However, recent studies indicate that non-surgical treatment should be recommended as first choice of treatment after ACL injury, since no differences has been found in patient reported outcome measures (PROM) or functional outcomes after 2-5 years. Furthermore, no decisive differences in the risk of developing knee osteoarthritis or increased risk of secondary meniscus injuries following non-surgical treatment compared to ACL reconstruction (ACLR) more than 10 years after the injury has been found. Treating more patients non-surgically with similar results to ACLR could avoid the disadvantages and risks related to surgical complications such as arthrofibrosis, infection, graft failure, donor site morbidity, pain, and surgical costs. However, a high frequency of patients remains, who will fail non-surgical treatment and will later be offered ACLR. These patients can be called non-copers. Early detection of these patients is imperative to ensure optimal recovery of functional capacity and rapid return to normal activity.

Treatment choice and evaluation of outcome following ACL injury is typically based upon a variety of objective measurements (knee laxity, muscle strength and functional performance) and PROMs such as the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Lysholm Knee scale and Tegner score. Nonetheless, to our knowledge, only one ACL specific screening tool has been developed to identify copers and non-copers to non-surgical ACL rupture treatment. This screening tool, originally proposed by Eastlack and colleagues, was developed based on previous studies reporting specific factors related to copers after ACL injury and later adjusted by Fitzgeral and collegues. The screening tool consists of four parts; 1) number of episodes of giving away, 2) Global Rating Scale (GRS) of knee function, 3) functional performance test (the 6-m timed hop test) and 4) a PROM, the Knee Outcome Survey (KOS). The screening tool has been used internationally and aims to determine symptoms and functional limitations in usual daily activities and sports participation in various knee pathologies. It can potentially provide valuable information on what treatment to recommend for patients after ACL injury. The tool has been shown to have moderate precision in identifying copers or non-copers early after injury, however, currently the tool may underestimate the number of possible candidates for non-surgical treatment. The underestimation of copers may be related to the KOS, which is developed to evaluate patients with mixed knee pathologies, and not validated in an ACL injured population, or due to selection of suboptimal prognostic factors to constitute the tool. Therefore, it may need to be further developed and optimized to improve the early identification of copers and non-copers to non-surgical treatment. This can help to ensure timely and patient centered treatment for each patient with an ACL injury.

Motivation

A timely and more precise identification of copers and non-copers can lead to better, more confident and targeted treatment plans for each patient, minimizing unnecessary concerns and possibly avoid risks and disadvantages related to ACLR. However, identification of significant predictive factors for copers and non-copers to non-surgical treatment is of great importance in the clinical practice and there may be a need for further development and optimization of the existing screening tool.

Description of the cohort

Patients will be consecutively recruited from the outpatient clinic in the Department of Orthopaedic surgery at Vejle Hospital, Denmark. After baseline assessments patients are referred to standard rehabilitation in their municipality. Inclusion criteria: unilateral primary ACL rupture in patients aged 18-49 years. Exclusion criteria: <3mm difference in anterior joint laxity compared to the uninjured knee, MRI verified large meniscus injuries (eg. Buckethandle laesions), large cartilage injuries (eg. Cartilage fragments requiring fixation) requiring acute surgery or multiligament ruptures. <3mm difference in anterior joint laxity compared to the uninjured knee, MRI verified meniscus, cartilage injuries or multi ligament ruptures requiring surgery. For all patients, it is mandatory that they speak, read and understand Danish.

All included ACL injured patients will complete the screening after 3 months rehabilitation. The screening is performed by a physiotherapist and performed prior to consulting with an orthopaedic surgeon. A follow up after 12 months is also planned. Patients will be contacted electronically to evaluate how many have underwent ACLR and will complete the KOS and the KOOS.

Data and biological material

Clinical and demographic data. The questionnaires Knee OUtcome Survey, KOOS, Lysholm, UCLA. Assessments of isometric muscle strenth and functional performance.

Collaborating researchers and departments

Department of Orthopaedic Surgery, Vejle Hospital

• Claus Varnum, MD, Phd

Department of occupational and physical therapy

• Kim Gordon Ingwersen, PT, Phd

Department of Orthopaedic Sugery, Odense University Hospital

• Bjarke Viberg