Surgery for patellar instability aims to restore the medial restraints of the patella and correct any anatomical predisposing factors, preventing further dislocations.
ℹ️ Pre-operative assessment includes blood tests, health check, and medication review. CT scan measurements of TT-TG distance and trochlear morphology should be reviewed before surgery to plan the correct procedure.
MPFL reconstruction takes approximately 60-90 minutes under general anaesthetic. Tibial tubercle transfer takes approximately 60-90 minutes. Both may be performed at the same time if required.
CT measurement of TT-TG distance and trochlear morphology should be reviewed before surgery. The planned procedure may be MPFL reconstruction alone, tibial tubercle transfer, or a combination.
Blood thinners must be paused. NSAIDs should be stopped 1 week before surgery. Inform your team of all medications.
A hinged knee brace and crutches are required after surgery. Arrange these before the day of surgery.
Post-operative physiotherapy is essential and should be booked before surgery, ideally starting in the first 1-2 weeks after the operation.
MPFL reconstruction usually uses a hamstring tendon graft (gracilis or semitendinosus) from the same leg, or occasionally from a donor (allograft). The choice of graft should be discussed with your surgeon before the day of surgery.
ℹ️ You will be given a specific arrival time. Do not eat or drink (other than clear water up to 2 hours before) from midnight the night before. Bring your medication list and any documents sent by the hospital.
You will be admitted to the ward or day surgery unit, change into a gown, and be seen by the nursing, anaesthetic, and surgical teams before theatre.
Your surgeon will confirm the procedure, mark the operative side, and you will sign a consent form before going to theatre.
You will meet the anaesthetist in the anaesthetic room. Once anaesthesia is established, the procedure will begin.
After surgery you will wake in the recovery room where nurses monitor your vital signs until you are stable and comfortable.
Most patients having arthroscopic or day-case procedures go home on the day of surgery. Those having joint replacement typically stay 1–2 nights. Before discharge, the team will check your pain is controlled, give you wound care instructions, and confirm your follow-up appointment.
You will be given oral pain relief before discharge. Take it regularly for the first 48 hours rather than waiting until pain is severe.
A nurse will check the wound before you leave and explain how to keep it clean and dry.
You will receive a letter for your GP and details of your next outpatient appointment - usually at 2 weeks for a wound check.
Arrange for a family member or friend to collect you. You must not drive on the day of surgery if you have had a general anaesthetic or sedation.
⚠️ Important: If you develop sudden severe knee pain, swelling, or the kneecap appears to be in the wrong position after surgery, attend A&E immediately. Wound infection signs (redness, heat, discharge, fever) also require urgent assessment.
Avoid getting the wound wet until it is fully healed - usually 10–14 days. Use a waterproof cover or cling film when showering.
Do not wait until pain is severe before taking medication. Regular simple analgesia (paracetamol, ibuprofen if appropriate) is more effective.
This is usually 2 weeks after surgery. Sutures or clips will be removed if used.
Seek urgent advice if you develop increasing redness, warmth, swelling, discharge from the wound, or a temperature above 38°C - these may indicate infection.
60-90 minutes in theatre. Home same day or next morning with brace and crutches.
Hinged knee brace protecting the MPFL repair. Crutches for 2-4 weeks. Progressive range of motion guided by physiotherapy.
Brace removed. VMO and hip strengthening. Swimming and cycling from 6-8 weeks.
Jogging from 3-4 months. Sport-specific drills progressing to cutting and pivoting from 4-6 months.
Return to competitive sport at 6-9 months, guided by physiotherapy-based functional testing including hop tests and quadriceps strength symmetry.
No. A hinged knee brace is used for protection in the first 6 weeks while the MPFL graft heals. A patellar stabilising brace may be used for return to sport, particularly in the first season back.
Recurrence rates after MPFL reconstruction in appropriately selected patients are below 5-10%. Higher recurrence rates are seen in patients with high-grade trochlear dysplasia who may require additional procedures (trochleoplasty).
Patients in office-based work usually return at 2-4 weeks. Standing or manual jobs typically require 6-12 weeks off. Heavy manual work or work involving ladders requires the brace to be removed and strength restored - usually 12 weeks or more.
Most patients return to driving at 4-6 weeks for the left knee in an automatic vehicle, and 6-8 weeks for the right knee or a manual vehicle. You must be off crutches, out of the brace if possible, and able to perform an emergency stop. Confirm with your insurer.
The aim of MPFL reconstruction is to restore the primary medial restraint of the patella, preventing further lateral dislocations and subluxations, and allowing return to sport without fear of the kneecap giving way.
Under general anaesthetic, a gracilis tendon graft is harvested from the medial hamstrings. The graft is attached to the medial patella using suture anchors and fixed in a bone tunnel in the femoral medial epicondyle. If the TT-TG distance is elevated (over 20mm), a tibial tubercle transfer is also performed to medialise the patellar tendon attachment. Both procedures may be combined. Takes approximately 60-90 minutes.
For a first dislocation without significant osteochondral injury or high-risk anatomy, physiotherapy and a patellar stabilising brace are the standard first-line treatment.
Appropriate when TT-TG is normal and there is no significant trochlear dysplasia.
Indicated when TT-TG exceeds 20mm. Medialization of the tibial tubercle reduces the lateral vector on the patella.
Deepening of the trochlear groove. Technically demanding procedure reserved for severe trochlear dysplasia (Dejour Types B-D) causing recurrent instability.
The MPFL graft can fail, resulting in recurrent patellar instability. Risk is higher in patients with untreated anatomical risk factors (high TT-TG, severe trochlear dysplasia).
The tibial tubercle osteotomy may fail to heal in its new position. May require revision surgery.
Wound or joint infection.
Limitation of knee movement after MPFL reconstruction. Usually resolves with physiotherapy.
Screws may require removal after healing.
Expected after surgery.
The MPFL graft and donor site on the medial side of the knee are sore for several weeks.
The knee is stiff in the early recovery period.
Recurrent patellar instability without surgical stabilisation will continue and may worsen, with each dislocation risking osteochondral injury and progressive patellofemoral cartilage damage. MPFL reconstruction significantly reduces recurrence rates and is the recommended treatment for recurrent instability.