Assessment of patients undergoing TKR, Surgical approaches , indications and contra indications of TKR

1. Preoperative assessment ,
surgical approaches , indications
and contraindications of TKR
Dr Humayun Israr
PGR Ortho
Sahiwal Teaching Hospital Sahiwal

2. Surgical approaches for TKR
• Anterior midline incision is used mostly
• Infra patellar branch of sephanous nerve is at risk
• May be dicatated by surgeons preference, previous incisions , patella baja,
obesity.
Approaches include
• Medial parapatellar approach
• Lateral para patellar approach
• Sub Vastus approach
• Mid-vastus approach

3. Surgical approaches
For revision arthroplasty
• Standard medial parapatellar approach
• Quadriceps snip
• Quadriceps V-Y turn down
• Tibial Tubercle osteotomy

4. Medial para patellar approach
Advantages
• Easy
• Most surgeons are familiar with it
• Excellent exposure
Disadvantages
• Lateral patellar subluxation
• Access to lateral retinaculum difficult

5. Lateral Para patellar Approach
Advantages
• Useful for fixed valgus deformity
• Preserves blood supply to patella
• Prevents lateral patellar Sub luxation
Disadvantages
• Technically demanding ( medial eversion of patella is difficult)
• May require tibial tubercle osteotomy.

6. Sub Vastus Approach
• Muscle belly of vastus medialis is lifted off intermuscular septum
Advantages
• Patellar vascularity preserved
• Extensor mechanism Preserved
• Minimal need for lateral retinacular release
Disadvantages
• Least extensile
• Potential for denervation of VMO
Relative Contra-indications
• Revision TKA
• Obese patient
• Large quadriceps
• Previous para patellar Arthrotomy

7. Mid Vastus Approach
• Similar To Medial Parapatellar but spares incision of VMO and may lead to quicker recovery
Advantages
• Vmo insertion on quad tendon is not disrupted
• Quicker recovery because extensor mechanism not disrupted
• Patellar tracking may be improved
Disadvantages
• Less extensile
• Exposure difficult in obese patients
• Exposure difficult in obese patients
Relative contra indications
• ROM < 80 degree
• Obese patient
• Hypertrophic arthritis

8. Quadriceps Snip
Technique
A snip is made at apex of quadriceps tendon obliquely across tendon at an angle of 45 degrees into
vastus lateralis.
Advantages
• Mininimal, if any , long term consequences
• No change in post operative protocol
Disadvantages
• Not as extensile as a turndown or tibial tubercle osteotomy.

9. Gastrocnemius V – Y Turn Down
Technique
• Straight medial parapatellar incision with diverging incision down the vastus lateralis tendon towards
the lateral retinaculum
Advantages
• Allows excellent exposure
• Allows Lengthening of Quadriceps tendon
• Preserves patellar tendon and tibial Tubercle
Disadvantages
• Extensor lag
• May effect quadriceps strength
• Knee needs to be immobilized post operatively

10. Tibial Tubercle Osteotomy
Technique
• 6-10 cm bone segment cut from medial to lateral
• Fixed with wires or screws
Advantages
• Excellent exposure
• Avoids extensor lag as seen wit V-Y Turn Down
• Avoids quadriceps weakness
Disadvantages
• Some surgeons limit weight bearing post operatively
• Tibial tuberosity avulsion Fracture
• Non union
• Wound healing Problems

11. Preoperative assessment of patients
• TKA should be clearly indicated.
Radiographs
• Standing AP and Lateral Views
• Skyline view of patella
• A long leg standinng AP radiograph of leg showing Hip and ankle
Templates can be used to anticipate component size and bone defects that would need to be
treated intra operatively.
The mechanical axis of femur can be measured to determine the proper distal femoral valgus
angle to properly make the resection and obtain neutral mechanical axis during the procedure.

12. Pre operative assessment of patients
Preoperative medical evaluation
• Must be detailed and thorough
• Comorbid diseases must be considered
• Patients with medical risk factors have longer hospital stays
• Smokers have more complications and longer hospital stays. Should be discouraged.
• Patient must have adequate cardiopulmonary reserve to withstand blood loss of 1500 ml over the
procedure. Electrocardiogram should be obtained perioperatively.
• Patients with CAD, CHF, COPD or restrictive pulmonary disease should be evaluated by appropriate medical
consultants
• Vascular supply to operative leg should also be evaluated. If questionable, non invasive arterial studies
should be obtained.

13. Preoperative assessment of patients
Preoperative Laboratory Evaluation
• CBC
• Electrolytes
• Urine analysis
• Chest X ray
 Evaluation of lipid and renal profile to look for co-morbids.
 Patients taking anticoagulant medication should be managed to limit blood loss.
 Poor nutrition often can be detected by low albumin level in the serum (< 3.5mg/dl)
 Patients with Low lymphocytes counts (<1200 cells/ml) have been shown to have longer hospital stays,
prolonged recovery times, longer anesthesia and surgery times and higher hospital charges as well.

14. Preoperative Assessment of patients
• Patients with diabetes should have HBA1C levels checked, and blood sugar should be well controlled.
• Obesity with the addition of two other comorbidities ( HTN, hyper-cholestrolemia or blood glucose
intolerance) is referred to as metabolic syndrome and is associated with higher complication risk. Patient
should be counselled regarding this.
• Outcome studies of morbidly obese patients show a high patient satisfaction rate but also a high risk of
Revision Surgery.
• No clear cut OFF BMI is established but clearly as comorbidities with obesity increase patients tend to have a
poor out come .

15. Anaesthesia Options
• Anaesthetist has full responsilbility with input from surgeon.
• Cardiovascular outcomes from general and regional anaesthesia have not proven to be
significantly different.
• Cognitive function is similar following regional and general anaesthesia.
Benefits of Epidural
• A slight decrease in overall DVT and PE rate has been reported with epidural anesthesia as
compared to general anaesthesia
• Vasodilation of lower extremity resulting in increased blood blow, haemodilution and decreased
blood viscosity.
• A fibrinolytic effect has been postulated for epidural anaesthesia.
• It allows indwelling catheter for 48 to 72 hours post operatively for pain control.
• Monitoring for respiratory depression should be done.

16. Anaesthesia Options
Side Effects of Epidural
• Pruritis
• Urinary retention
• Nausea
• Vomiting
• Formation of an epidural hameatoma
The use of low molecular Weight Heparin for DVT prophylaxis along with postoperative epidural
analgesia is not recommended because of the increased risk of epidural haematoma and
potentially disastrous neurologic sequelae.

17. Indications of TKR
• To relieve pain caused by severe arthritis
• Indicated in older individuals with sedentary life style.
• In younger individuals with severe functional impairment from
osteoarthritis or systemic arthritis with multiple joint involvement or
osteonecrosis with subchondral collapse of a femoral condyle.
• Sometimes indicated in severe patellofemoral arthritis.
• Deformity can become indication for arthroplasty in patients with
moderate arthritis and variable levels of pain.

18. Contraindications OF TKR
Absolute
• Recent or current knee Sepsis
• A remote source of ongoing infection
• Extensor mechanism discontinuity or severe dysfunction
• Recurvatum deformity secondary to neuromuscular weakness
• Presence of a painless & well functioning knee arthrodesis

19. Contra-indications
Relative
• Medical conditions that affect patient s ability to withstand anaesthesia
• An ipsilateral osteoarthritic hip
• Severe atherosclerotive disease of operative leg
• Skin conditions like psoriasis
• Venous stasis with recurrent cellulitis
• Neuropathic arthropathy
• Super obesity BMI > 50
• Recurrent urinary tract infection
• Hx of osteomyelitis in proximity of knee

20. Thank You For your Attention