Dr (Prof) Raju Vaishya (MBBS, MS, MCh (L’pool), FRCS (Eng) Sr Consultant Orthopaedics & Joint Replacement Surgery Indraprastha Apollo Hospitals, N Delhi

Problems of present TKRs  Wide range of sizes, designs & modular options  Variation of inherent stabilities in different designs  Variation in surfaces (flat to fully dished)  Meniscal v/s fixed bearing v/s rotating hinges  Increasing cost of implants

Old & New things in life

Why change?  To improve on established results  To improve the life span of prosthesis  To improve the quality of life (unrestricted activities!)  To decrease the tissue trauma during surgery  To make the surgery reproducible

Present & Past TKRs PASTPRESENT Operating time 4-6 hours 1 hour Recovery time 3-6 months 1 month Blood transfusion 3-4 units 1unit Pain Moderate to severe Minimal Range of motion 90 degrees degrees Permitted ADL Major restrictions Mostly allowed Incision length cms 10 cms Hospital stay days 4-5 days Life span 8-10 years years

MIS (Muscle sparing) approach Computer navigation Reduction in bleeding Pain relief measures Single use instruments

MIS using Muscle sparing approach  Indicated for non-obese patients with preop flexion > 90 deg, varus deformities <20 deg or valgus deformities <15 deg  Goal of MIS is to limit the muscle and tissue dissection without compromising the procedure (8-10 cms incision)  Modified version of one of the standard TKA exposures — subvastus, midvastus, or medial parapatellar — or through an MIS Quad- Sparing arthrotomy

Reduction in bleeding  Adequate thermal coagulation, before closure  Local infiltration of cocktail (incl Adrenaline)  IV Trenaxamic Acid (3 doses at 3 hour interval)  Plugging of femoral medullary canal

Pain in TKA Adequate post-operative pain relief following TKA is very important to optimal post-operative recovery

Multi-modal analgesia  Involves the use of multiple agents that act at different regions of the pain pathway  Combining different classes of analgesic drugs is important to facilitate rehabilitation after TKA  Pre-emptive analgesia, using local periarticular injections, and the introduction of a comprehensive postoperative pain protocol.

Multimodal analgesia - methods  Preemptive analgesia  Local wound infiltration  Nerve blocks  Single shot  Indwelling catheter  Epidural infusions  Analgesics  Single shot  Infusions  PCA

‘Cocktail’ for Pain relief For each knee: Inj Bupivacine (0.25%) - 20mls Inj Ketorolac (30mg) - 01ml Inj Morphine (15mg) - 01ml Inj Gentamicin (80mg) - 02mls Inj Adrenaline (1%) - 01ml Inj Normal Saline - 50mls TOTAL : 75mls

1. Pain relief: a.VAS VAS scoring at rest Mean VAS pain score at rest was lower in intervention group than in control group (p < 0.001) at 6 hrs, 24 hrs,48hrs and 72hrs (Figure 9).

b. Opoid Consumption : Analysis of data revealed that the total mean morphine consumption was significantly lower in the intervention group during the seventy two hours postoperatively compared to control group( figure11)

Newer designs 1. Gender specific knees 2. High flex knees 3. Customized knees

Gender specific implant Smaller medio-laterally for Females

High Flex knees  Special design  Requirements: -Good pre op ROM -Thinner thighs -Ability to co operative in post op rehab Preferably done with PS designs & patellar resurfacing

Advances in TKA  Surgical robots are not popular due to: - higher cost - the set up time required preoperatively - limited application they presented

Advances in TKA  Computer navigation – although considered GOLD STANDARD due to better alignment, but had potential disadvantages of – - significant capital outlay - additional preoperative set up - cumbersome in the operating room, taking up substantial floor space

Advances in TKA  Gender specific implants – introduced to accommodate the infinite variation in patient geometry.  Disadvantages – - Size and constraint variation accompanied by mountains of reusable instrumentation and instrument trays. - Financial investments required for the companies to purchase and maintain this inventory is substantial.

Customized approach for TKA  Nowadays, the concept of customized implants in arthroplasty has shifted to making customized “JIGS” which help in making the distal femoral and proximal tibial cut.  Use is made of standard off-the-shelf knee implants. Either a CT or MRI is taken of the patient’s knee.

ADVANCES IN TOTAL KNEE ARTHROPLASTY  Traditional technique: I/M femoral guide and E/M tibial guide.  Computer assisted system: Intra operative planning.  Patient specific instruments: Pre operative planning.

Customized jigs  A new and innovative technology.  Improves alignment and sizing of the joint by using computer-generated images of the patient’s anatomy to determine precise bone cuts, and implant positioning during the surgery.

Customized jigs PRINCIPLE Achieving accurate postoperative mechanical alignment by preoperative planning and using patient specific blocks, thus minimizing human errors in bone cutting.

Technique for jig manufacturing  MRI based - better suited for soft tissue. Segmentation process performed on surface of articular cartilage.  CT based - better suited for imaging of hard tissue. Segmentation process performed on sub chondral surface creating an image of bone.

Customized Jigs  Patient matched disposable femoral and tibial cutting blocks are prepared using patients anatomical data obtained from long leg CT scannogram or MRI images

Custom fitting blocks Femoral PSI JigTibial PSI Jig

Step 1: ExaminationStep 2: Scan Step 3: Segmentation Step 4: Pre Op Plan Preparation Step 5: Pre Op Plan Approval Step 6: Jig Designing Step 7: Manufacturing Step 8: Shipping Step 9: Surgery

HOW IS PSI DIFFERENT..?  Less invasive: No use of intramedullary femoral alignment guide.  Less operative time: Many steps are by passed.  Human error is minimised: Patient specific blocks used for pin position.  Intra operative complications avoided: Pre operative planning.

Postoperative mechanical alignment  With preoperative planning and use of patient specific blocks, chances of achieving neutral mechanical axis are increased.

Our experience - PSI  There are a number of potential advantages like less number of opened tray, decreased sterilization time and quicker patient turnover in a high volume replacement centre.  The cost and time duration for making the custom blocks can be reduced by local manufacturing of the blocks. The cost has been brought down to $400 and delay in blocks decreased to 1 week at our centre. Vaishya R et al. J Arthroplasty Jan 30. doi: /j.arth Vaishya R et al. International Orthopaedics, (SICOT) March In press.

Benefits of PSI  SURGEONS: 1. Easy and simple technique with minimal learning curve. 2. More efficient surgery- less no. of instruments & trays. 3. Greater accuracy- pre-op determination of alignment & sizing. 4. Increased patient satisfaction- less traumatic surgery.

Benefits of PSI  HOSPITAL: 1. Cost saving- less no. Of instruments & trays to clean & sterilize. 2. Inventory reduction-less no. of trays to store & maintain. 3. Better OR utilisation-less OR time, so more patient turn over.

Benefits of PSI  PATIENTS: 1. Less invasive procedure- no violation of I/M canal. 2. Faster surgery- leads to less blood loss & anaesthesia use. 3. Faster return to routine activities- faster & more productive recovery

Newer Joint Replacements  Artificial components are made of stronger, more durable materials & more customized designs  Can be implanted using MIS  Recovery time is shorter  Outcomes are vastly improved

Future Designs  ‘High performance’ knee  Upgrade in polyethylene quality  Harder material or coating for femoral components  Advances in instrumentations  Customized approach (for unusual/difficult cases)  Change in manufacturing methods or materials

It appears that the surgeons are more happy after TKR than the patients!

Thank You