Patellar Instability: Physiotherapy or Surgery? (PIPS feasibility trial)

INTERVENTION: Participants will be randomly assigned by a computer to either a surgical arm or a non‐operative arm consisting of a Personalised Knee Therapy. Personalised Knee Therapy: Participants allocated to this treatment will be referred to a qualified physiotherapist who has been instructed in this specific treatment. The package of care has been developed by experts in the field specifically for this trial. This treatment does not add any risks or difficulties in case there is a need for surgical intervention in the future. Participants will attend an initial session with the physiotherapist who will assess the participants, the problems they face in daily life and their current strategies for managing their condition, and design a treatment plan specific to them. They will assess function and strength at the knee and will also assess trunk, hip, knee and ankle control. Participants will be invited to attend at least 6 sessions over a 3 month period and may be invited to more sessions or for more time if they need it. The initial session may be up to an hour, but other sessions will typically be shorter. The treatment will change over time as participant’s legs strengthen or symptoms change. When the course is finished, participants will be given instructions and guidance how to maintain the strength and control in their leg. Surgery: Participants allocated to this treatment will be assessed by a surgeon and they will decide on the best operation. This is likely to be either a MPFL (medial patellofemoral ligament) reconstruction, a tibial tubercle osteotomy, or both. All of the operations used in this study have been available on the NHS for over 10 years and there will be no new or experimental operations used on participants. A MPFL (medial patella‐femoral ligament) reconstruction involves 3 small incisions (around 4 cm each) over the knee, as well as two keyhole scars (around 5 mm). One of the hamstring tendons is used to make a new ligament and is attached to the kn CONDITION: Patellar instability ; Musculoskeletal Diseases ; Patellar instability PRIMARY OUTCOME: Norwich Patellar Instability Score (NPIS) at 12 months SECONDARY OUTCOME: 1. The Norwich Patellar Instability Score (NPIS) at baseline, 3 and 6 months. ; 2. The Banff Patella Instability Index (BPII) at baseline, 3, 6 and 12 months.; 3. The Kujala score at baseline, 3, 6 and 12 months; 4. The Oxford Knee Score – Activity and Participation Questionnaire (OKS‐APQ) at baseline, 3, 6 and 12 months; 5. The EuroQol EQ5D (EQ5D‐5L) at baseline, 6 weeks and 3, 6 and 12 months INCLUSION CRITERIA: 1. Provision of written informed consent 2. Aged 16 or over and has closed growth plates on MRI scans (taken as part of standard clinical care) 3. Two or more patella dislocations, OR 1 dislocation with over 6 months of subjective instability leading up to the time of recruitment