A randomised controlled trial of the Cross-Bracing Protocol versus comprehensive rehabilitation for people with acute anterior cruciate ligament rupture

NAME Cross Bracing Protocol (CBP) including comprehensive rehabilitation RATIONALE Immobilising the knee at 90 degrees flexion is proposed to facilitate ACL healing by approximating the torn ligament ends. MATERIALS 1) A specialised knee brace (Bauerfeind SecuTec Genu brace (ARTG 303564) https://bauerfeind.com.au/products/secutec-genu-cross-bracing-protocol) will be supplied and fitted by a physiotherapy clinic. 2) Elbow or axillary crutches will be supplied by a physiotherapy clinic. 3) Participants may access mobility aids (such as an iWalk - https://www.iwalknz.co.nz/ - or Knee Scooter - https://www.kneescooters.co.nz/) through the Accident Compensation Corporation (ACC). Access to aids will be arranged outside of the trial by the physiotherapist, participant, and ACC. 4) Rehabilitation equipment supplied by a physiotherapy clinic according to participant need (such as, exercise bands, access to gym equipment). 5) Anti-coagulation medication will be recommended for all participants aged 16 years and older in the CBP arm but this will not be mandatory. Medication will be prescribed by a doctor affiliated with the study and supplied by a community pharmacy. Participants will be supplied a voucher to pay for prescription costs. Most participants will be prescribed 10mg oral rivaroxaban once daily until the end of week 6 in the brace. If rivaroxaban is contraindicated, 40mg enoxaparin injections once daily for 6 weeks may be prescribed. 6) An information booklet developed for this trial explaining ACL injury, CBP, tips and tricks for managing life while in a brace, the recovery journey, rehabilitation phases and goals, and medication use and side effects. This is not yet publicly available. PROCEDURES A brace will be fitted as soon as possible after randomisation and deep vein thrombosis screen by a trained physiotherapist. Brace fitting must occur in the first 21 days after ACL rupture to be eligible to participate. An 8-week bracing protocol will be used. The injured knee will be fixed at 90° flexion in a knee brace at all times for the first three weeks, including during sleep. After week 3, the knee brace will be adjusted weekly to allow progressive increases in knee range (60-90° flexion at 4 weeks from bracing initiation, 45-90° flexion at 5 weeks, 30° to 90° flexion at 6 weeks, 10° to 120° flexion at 7 weeks, unrestricted range at 8 weeks, and the brace removed at the end of week 8). Weight bearing as tolerated will be introduced at 6 weeks and full weight bearing is expected in week 8. Participants will be instructed that they can remove the brace while seated for self-massage, moisturising skin, showering etc, provided their knee remains in the range of movement recommended by their study physiotherapist. Participants will take part in physiotherapist-supervised goal-oriented exercise-based rehabilitation while in the brace and after its removal. Rehabilitation will be funded by ACC. Rehabilitation will be structured in four phases with phase progression determined by attainment of specific milestones. Phase 1: Cross Bracing and period immediately after removal. This includes a progressive in-brace exercise programme (including ipsilateral and contralateral lower limb strengthening exercises, aerobic exercise, and range of movement exercises). 1) Intensity will be determined by physiotherapist depending on symptoms and concomitant injury. Intensity will build across the 8 weeks in the brace and is permitted to reach Borg Rating of Perceived Exertion of 9/10 by week 8. 2) Exercise examples: weeks 1 to 3 (isometric hamstrings and quadriceps, wall sits, hover squats, seated calf raises gluteal bridges); week 4 (addition of double / single leg press, standing or resisted calf raises, resisted hip flexion, extension, abduction, adduction); week 5 (addition of squats, resisted knee flexion, single leg press / calf raise / bridges, resisted crab walk, seated foot slides); week 6 (addition of weighted squats); week 7 (addition of gait retraining, dead lifts, lunges, balance exercises, exercycle); week 8 (addition of single leg squats / dead lifts). 3) Criteria for progression: a) No morning swelling b) Full active and passive extension c) Flexion 100° or greater Phase 2: Reactivation. This phase focuses on building knee strength, restoring range of motion, restoring balance and walking confidence. 1) Intensity target: Borg Rating of Perceived Exertion of 6 to 7/10 (or greater if higher intensity achieved during bracing phase); 2) Exercise examples: exercycle; gait retraining; squats; leg press; single leg stance; resisted knee flexion and extension; standing calf raises; single leg bridges; resisted hip flexion, extension, abduction, adduction. 3) Criteria for progression: a) Knee flexion range of motion 120° or greater b) Normal gait pattern with full weight bearing c) Able to one-leg stand without difficulty Phase 3: Restoration of function. This phase focuses on restoring strength and dynamic knee stability. This includes perturbation (balance) training and neuromuscular control with functional movements, such as squatting, lunging, hopping, and landing. 1) Intensity target: Borg Rating of Perceived Exertion of 8 to 9/10; 2) Exercise examples: weighted squats; deep side step ups and down; resisted knee flexion and extension; leg press; dead lifts; multiplanar lunges; resisted crab and monster walks; explosive strength; reactive strength; agility drills; perturbation training. 3) Criteria for progression: a) 80% quadriceps and hamstring strength symmetry. Assessed with 1 Repetition Maximum as per clinical standard practice – this may be with gym-based equipment, hand-held dynamometer, or isokinetic dynamometer) b) 80% hop test symmetry with adequate movement quality. Assessed with single leg hop for distance and single leg vertical jump Phase 4: Progressive sport specific training. This phase focuses on impairment-specific heavy strength training, power and agility drills, explosiveness and sport-specific exercises individualised to the participant’s specific goals and sporting demands. After passing return to sport criteria, there is a staged progression from modified training (e.g. non-contact) to restricted contact training (such as small sided contact practices), to full training, to restricted competition participation (restricted minutes), to unrestricted competition participation. 1) Intensity target: Borg Rating of Perceived Exertion of 9/10; 2) Exercise examples: impairment specific heavy strength training; explosive strength; reactive strength; sport-specific agility drills; high intensity, reactive, unpredictable and sport specific agility training; sport-specific exercises. 3) Criteria for return to sport: a) Sufficient agility for their sporting / activity demands b) 90% quadriceps and hamstring strength symmetry. Assessed with 1 Repetition Maximum as per clinical standard practice – this may be with gym-based equipment, hand-held dynamometer, or isokinetic dynamometer) c) 90% hop test symmetry with adequate movement quality. Assessed with: single leg hop for distance, triple cross-over hop, and single leg vertical jump d) Psychological readiness scores of 90 out of 100 or greater, assessed the ACL Return to Sport After Injury Scale (ACL-RSI; knee confidence and psychological readiness) Participants will cease rehabilitation when they achieve criteria for return to full activity. This usually occurs 6 to 12-months after injury. Participants will be advised to delay full return to sport until at least 9 months post-injury to enable development of sufficient strength and co-ordination and maturation of any ACL healing. WHO Brace fitting, adjustment, and rehabilitation will be provided by registered physiotherapists who have completed online e-learning and an in-person brace fitting workshop conducted by the brace manufacturer. Medication prescription will be provided by medical practitioners (sports and exercise medicine physicians, orthopaedic surgeons, and general practitioners) affiliated with the trial. HOW Physiotherapy consultations will be in-person but may occur online via telehealth when someone is unable to attend in-person (due to illness or emergency). Rehabilitation will usually be one-on-one but may be delivered in group settings depending on standard practice within the physiotherapy clinic; this will be determined by the physiotherapist in collaboration with the participant. Medication prescription consultations may occur in-person or via telehealth. WHERE Rehabilitation will be delivered in community-based physiotherapy clinics. Clinics are expected to have gym facilities or provide access to such facilities to participants. Consultations may be shifted to other locations (such as community-based facilities or sports fields) depending on participant preference and rehabilitation requirements. WHEN AND HOW MUCH On average, participants will receive 22 physiotherapy consultations over a 12-month period (for example: initial consultation and follow-up consultations weekly at weeks 1-8 and weeks 9, 11, 13, 15; and then monthly across months 4-12). Timing of visits will need to be flexible to meet individual participant needs. Discharge to self-care may occur earlier than 12 months depending on participant context and needs. Consultations will occur weekly while the person is wearing the brace (weeks 1-8) to allow deep vein thrombosis, medication side effect, and adverse event screening, monitoring adherence, adjustment of brace movement restrictions, and progression of the in-brace exercise programme (including ipsilateral and contralateral lower limb strengthening exercises, aerobic exercise, and range of movement exercises). This will result in CBP arm participants on average having 4 more physiotherapy consultations that those in the control arm. Physiotherapy consultations will be between 30 and 60 minutes in duration. TAILORING The Cross Bracing Protocol will only be adapted in instances of participant adverse events, such as identification of deep vein thrombosis (in which case brace use will be terminated) or skin irritation / damage (in which case wear may be modified as deemed clinically appropriate). Physiotherapists will adapt rehabilitation programme content and duration, as well as consultation frequency and quantity to match participant context and need. ADHERENCE Assessed by physiotherapist case report forms and study specific adherence item in the follow-up surveys.