Proximal fibular osteotomy

Proximal fibular osteotomy, PFO, High tibial osteotomy

1.                                                     D r Atanu Kayal                                                                                        post Graduate Trainee                                                                                        Burdwan Medical College                                             Proximal fibular osteotomy for pain relief and improvement of joint function in patients with medial compartment osteoarthritis of knee

2. Introduction and Aim Knee Osteoarthritis being a leading cause of disability among older adults globally. Available surgical management : High Tibial Osteotomy( HTO ), Unilateral Knee Arthroplasty ( UKA ), Total Knee Arthroplasty ( TKA ). Proximal fibular osteotomy(PFO) is an alternative treatment to HTO and it is safe , simple, less expensive and requires lesser rehabilitation , and the post- operative recovery period is faster than with HTO.

3. Principle Mechanism  ? still unclear ? One possible explanation: The fibula supports one-sixth of the body weight; thus, PFO may redistribute the load on the lateral and medial tibia plateau after surgery. Another : Non-uniform settlement as proposed by Yang et al.

4. Non-uniform settlement The support of fibula over lateral condyle tibia transmit weight but medial condyle tibia has no such support which  , leads to non -uniform settlement  . Due to change of slope of medial tibial plateau produce transverse shearing of force to cause a medial shift of femoral condyle during weight bearing. It results in medial shift of mechanical axis ….........VARUS deformity.

5. How does it work? After PFO the proximal fibular segment become free from tibiofibular syndesmosis and distal fibula,  leading to relative increase ROM  of the proximal tibiofibular joint. The lateral joint space of the knee is narrowed to counteract the varus deformity during weight bearing.

6. Case Selection Inclusion Criteria 1.Varus Knee (>5 degree) 2.Moderate to severe medial compartment OA when conservative treatment fail. 3.Age >40 years 4. Radiological grading of 1 and 2 (KL grading). Exclusion Criteria Tri-compartmental Osteoarthritis Varus knee >10 degree Obese patient  (BMI>30) 4. ligamentous instability 5. Kellgren Lawrence grade  grading(KL)- 3 and 4.

7. Methodology Sample Size: 1 Study design: Institution based prospective  Parameters to be studied:   -Visual Analogue Scale ( VAS)   -  Western Ontario and McMaster Universities Arthritis Index (WOMAC) sore

8. Procedure Placed in supine position under anaesthesia Pneumatic Tourniquet used 6cm skin incision is made over right  lateral aspect and fibula exposed between peroneus and soleus. Fibular osteotomy performed removing 2-3 cm fibula from 8 to10 cm away from Caput fibulae. Allowed immediate mobilization and pain permitted weight bearing as soon as possible.

9. Procedure

10. Result and Analysis The Patients was followed up for  6 months. Decent amount of pain relief are seen , graded by VAS ( For pain) and WOMAC score ( For pain, stiffness and functional activity).  The ratio of knee joint space medial /lateral compartment improved from 0.33preoperatively to 0.6 post-operatively.         VAS Score Pre-op 7.6 Post Op 2.8 WOMAC Score Pre op 45.2 Post Op 22.2

11. 6 months follow-up

12. DISCUSSION PFO has been proposed as an attractive option for pain relief in patients with medial compartment KOA . The most common complication: Transient neural injury to peroneal nerve. Though provide good outcome in short term follow up as a simple surgery, to reach to a reasonable conclusion about its  limited role.

13. PFO vs HTO vs UKA Proximal fibular osteotomy(PFO) High tibial osteotomy  (HTO) Uni compartmental knee Arthroplasty            ( UKA) Simple, safe , fast, affordable surgery. Does not require any IMPLANT. Early rehabilitation possible Technically demanding procedure. Require IMPLANT ( TOMOFIX/ Locking T plate). High surgical training needed to overcome correction error( under correction and over correction and excessive posterior slope change) Delayed rehabilitation Technically demanding procedure. Require IMPLANT . High surgical training needed to overcome correction error( under correction and over correction) Delayed rehabilitation

14.                                             Limitations of Study Most of developing countries that lack of medical resources and healthcare delivery limitations, proximal fibular osteotomy is an excellent option for pain relief and improve knee functions. provide good outcome in short term follow up as a simple surgery, to reach to a reasonable conclusion about its  limited role . Engaging with floor bending activities , squating of Indian populations leads to chance of failure of Uni -condylar knee arthroplasty surgery. Average cost of total knee replacement of a single knee cost around 1.4 to 1.8 lakhs, in India where average income of Indian household is approximately 1.2 lakh/ year which means for one knee surgery they have to spend entire income of 1 year.

15. Take home message