MS Orthopaedics - Paper IV (Recent Advances) KNRUHS

Top 20 Expected Questions - Theory Examination 2025/2026

ESSAY QUESTIONS (Long Answer - 20 marks)

SHORT ESSAY QUESTIONS (10 marks each) - Most Expected

Summary Frequency Table

Very Recent Advances to Add (2024-2026, Campbell's 15th Ed)

• Robotic-Assisted Arthroplasty: MAKO (Stryker) for TKA/THA - haptic feedback, bone-saving cuts
• Augmented Reality (AR) Navigation: Intraoperative AR for implant positioning
• Unilateral Biportal Endoscopy (UBE): New MIS spine technique
• Cementless TKA: Data on outcomes vs cemented
• Unicompartmental Knee Arthroplasty (UKA): Indications, conversion to TKA
• Ibuprofen/NSAIDs effect on fracture healing: Reconsidered in recent literature
• JAK Inhibitors (tofacitinib, baricitinib): New biologics class for RA
• Exosome therapy: Newer than stem cells in cartilage/bone healing
• 3D Printing / Patient-Specific Implants: Custom cutting guides, patient-specific implants in revision surgery
• Enhanced Recovery After Surgery (ERAS) in Arthroplasty: Multimodal analgesia, early mobilization protocols

Exam Strategy Tips

1. Every answer in Paper 4 must mention "recent advances" - examiners expect the contemporary update even for a classical topic.
2. For any arthroplasty topic, mention robotic assistance and kinematic alignment as the current trend.
3. For biologics/PRP topics, mention classification systems and level of evidence - examiners love this.
4. Masquelet technique and BMP often come together - prepare them as a combined answer.
5. For spine topics, always contrast old approach vs new (open vs MIS, fusion vs motion preservation).

KNRUHS MS Orthopaedics - Paper IV (Recent Advances)

Top 20 Expected Questions

1. Autologous Chondrocyte Implantation (ACI) / MACI - (most repeated, asked 2013, 2015, multiple sessions)
2. Computer-Assisted Navigation in Orthopaedic Surgery - (asked 2013, 2014, 2015 - extremely high frequency)
3. Recent trends in management of injuries of the Cervical Spine - (asked in literally every paper - 2009, 2013, 2014, 2015, 2024)
4. Platelet-Rich Plasma (PRP) - types and uses in Orthopaedics - (asked 2013, 2015)
5. Bone Morphogenetic Protein (BMP) and its role in Orthopaedics - (asked 2014, 2015)
6. Minimally Invasive Spine Surgery (MISS) - (asked 2014, 2015)
7. Limb Salvage Surgery in Osteosarcoma / Malignant Bone Tumors - (asked 2008, 2013, 2014, 2015)
8. Tribology - What is it? How has it changed clinical orthopaedic practice? - (asked 2013 and 2015 in identical wording - likely to repeat)
9. Revision Knee Arthroplasty - recent developments - (asked 2014, 2015)
10. Locked Compression Plate (LCP) / LISS / MIPO technique - (asked 2008, 2014)
11. Induced Membrane Technique (Masquelet) in bone defects / osteomyelitis - (asked 2013)
12. TNF-alpha antagonists / Biologics in Rheumatoid Arthritis - (asked 2013)
13. Antibiotic-Impregnated Bone Cement / Local antibiotic delivery systems - (asked 2015)
14. Radiofrequency Ablation (RFA) in Osteoid Osteoma / bone tumors - (asked 2013)
15. Polytrauma management - Damage Control Orthopaedics (DCO) - (asked 2013)
16. Cruciate-sparing vs Cruciate-sacrificing Total Knee Arthroplasty - (asked 2013)
17. Recent advances in Total Hip Arthroplasty (bearing surfaces, approaches, ERAS) - (asked 2009, 2015 pseudotumor/MOM)
18. Periprosthetic fractures of femur / knee (Vancouver classification, management) - (asked 2014)
19. Rotator Cuff - recent trends in management - (asked 2013)
20. Robotic-Assisted Surgery / AI and 3D printing in Orthopaedics - (emerging topic, highest probability for 2025-2026 exams given global and KNRUHS syllabus updates)

Questions 1, 2, 3, 8 have appeared in near-identical wording across sessions - prepare these as priority. Q20 is the single most likely "new" topic the examiner will test in 2025-2026 that hasn't been asked before.

Robotic-Assisted Surgery, AI, and 3D Printing in Orthopaedics

Structured Answer - 15 Marks | MS Orthopaedics Paper IV

INTRODUCTION (1 mark)

I. ROBOTIC-ASSISTED ORTHOPAEDIC SURGERY (5 marks)

Classification of Robotic Systems

A. MAKO SmartRobotics (Stryker) - Most Widely Used

• Uses CT-based preoperative 3D planning
• Intraoperatively, a haptic boundary (AccuStop technology) constrains the cutting burr - prevents inadvertent bone removal outside the planned zone
• Applications: Total Knee Arthroplasty (TKA), Total Hip Arthroplasty (THA), Partial Knee (UKA)
• Advantages:
  • Improved component alignment and positioning
  • Reduced outliers in implant orientation
  • Lower revision rates for dislocation in THA (Bendich et al., J Arthroplasty 2022)
  • Bone-conserving, patient-specific cuts

B. ROSA Knee (Zimmer-Biomet)

• Registration using bone morphing (no preoperative CT required)
• Soft tissue balancing capability in real-time
• Approved for TKA and, since February 2024, for total shoulder arthroplasty (ROSA Shoulder) - first FDA-approved robot for shoulder replacement

C. Robotic Spine Surgery

• Mazor X (Medtronic) and ExcelsiusGPS (Globus Medical) for percutaneous pedicle screw placement
• CT-to-fluoroscopy image fusion guidance
• Reduces screw malposition and radiation exposure to surgeon

Clinical Advantages of Robotic Surgery

1. Reproducible bone cuts independent of surgeon fatigue
2. Real-time intraoperative feedback
3. Better soft tissue balancing in TKA
4. Reduced outliers in coronal, sagittal, and rotational alignment
5. Potentially improved implant longevity

Limitations

• High capital cost
• Steep learning curve
• Increased operative time initially
• Outcome benefit over conventional surgery still debated at long-term follow-up

II. ARTIFICIAL INTELLIGENCE (AI) IN ORTHOPAEDICS (4 marks)

Definition

Applications

• AI algorithms analyse radiographs/CT scans to automatically measure deformity, templating implant size
• AI-based systems (e.g., TraumaCad) for fracture classification and pre-op templating
• Predicts surgical complexity and estimated blood loss

• Real-time AI-assisted navigation superimposed on fluoroscopy
• Integration with robotic systems for dynamic force line optimization during TKA
• Augmented Reality (AR): AR headsets project CT/MRI anatomy onto the surgical field - under active development for spine and pelvis surgery

• Deep learning models detect radiographic fractures with accuracy comparable to experienced radiologists
• Automated AO/OTA fracture classification from X-rays

• ML models predict 90-day complications, readmission risk, implant failure
• Patient-specific discharge planning and rehabilitation protocols

• Smart implants with embedded microchips/sensors monitor load, temperature, and micromotion in real-time - early detection of periprosthetic loosening (emerging technology)

III. 3D PRINTING (ADDITIVE MANUFACTURING) IN ORTHOPAEDICS (4 marks)

Principle

Applications in Orthopaedics

• Custom prostheses for complex revision arthroplasty with significant bone loss
• Acetabular cage reconstructions in massive bone defects
• Custom cutting guides (PSI guides) for TKA and osteotomies - improve accuracy without robotic system

• 3D-printed bone models for complex fractures (acetabular, tibial plateau) allow surgeon to rehearse reduction and fixation
• Reduces intraoperative time and improves execution

• Titanium implants with 3D-printed trabecular (lattice) structures mimicking cancellous bone
• Porosity of 60-80% promotes osseointegration (bone ingrowth)
• Examples: Stryker Tritanium, Zimmer Biomet Trabecular Metal-equivalent structures

• Custom mega-prostheses for large tumour resections (after limb salvage surgery)
• Complex pelvis and sacral reconstructions

• 3D-printed titanium cages for interbody fusion (TLIF, ALIF)
• Surface porosity enhances fusion rates

• Printing of scaffold structures seeded with cells (chondrocytes, stem cells) for cartilage regeneration - preclinical stage, promising

Materials Used

SUMMARY / COMBINED ADVANTAGE (1 mark)

• Fewer outliers in implant alignment
• Reduced revision rates
• Shorter hospital stays (combined with ERAS protocols)
• Better functional scores and implant longevity

DIAGRAM TO DRAW IN EXAM

CT Scan → 3D Digital Model → AI Planning → Robotic Execution → Smart Implant Monitoring

Smart Implants in Orthopaedics

Structured Answer - 10 Marks | MS Orthopaedics Paper IV

INTRODUCTION (1 mark)

COMPONENTS OF A SMART IMPLANT (1 mark)

1. Sensor unit - measures load, pressure, strain, temperature, pH, or motion
2. Microprocessor - processes and encodes sensor data
3. Wireless telemetry module - transmits data (Bluetooth Low Energy / near-field communication)
4. Power source - micro-battery or energy-harvesting systems (motion-based piezoelectric, ultrasound-powered)

TYPES AND CLINICAL APPLICATIONS (4 marks)

1. Smart Knee Implants

• Persona IQ (Zimmer Biomet + Canary Medical) - the world's first FDA-approved smart knee replacement
• Embedded sensor measures: step count, walking speed, range of motion, gait symmetry, and cadence
• Data transmitted to the mymobility digital platform viewable by surgeon and patient
• Enables remote rehabilitation monitoring and personalised physiotherapy protocols
• Detects early loosening or malalignment by tracking progressive changes in load distribution

2. Smart Hip Implants

• VERASENSE (OrthAlign / Stryker) - intraoperative tibial/femoral sensor trial for soft tissue balancing during TKA and THA
• Measures compartment loading in real-time during trial reduction
• Allows surgeon to optimise soft tissue balance before final implantation
• Reduces postoperative instability and accelerated polyethylene wear

3. Smart Fracture Fixation Devices

• Instrumented intramedullary nails with strain gauges to monitor fracture healing progression
• Load-bearing data identifies when callus is sufficiently mineralised for full weight-bearing
• Reduces radiation exposure (replaces serial X-rays for healing assessment)
• Experimental systems used in clinical trials for tibial and femoral nail monitoring

4. Smart Spinal Implants

• Pedicle screw systems with embedded sensors detect toggling / loosening early
• Interbody cages with pressure sensors monitor fusion status
• Telemetric rods in growing spine constructs for scoliosis - adjust remotely without repeat surgery (remote adjustment systems)

5. Smart Bone Cement / Infection Monitoring

• Antibiotic-eluting cement with embedded electrochemical biosensors for early periprosthetic joint infection (PJI) detection
• Sensors measure inflammatory biomarkers (IL-6, CRP equivalents) locally
• Preclinical stage but highly promising for early PJI diagnosis

ADVANTAGES (1.5 marks)

LIMITATIONS AND CHALLENGES (1.5 marks)

1. Biocompatibility of electronic components over decades - microelectronics must withstand body fluids lifelong
2. Power supply - micro-batteries need replacement or energy harvesting remains insufficient for long-term use
3. Data security and privacy - wireless transmission of patient health data (cybersecurity risk)
4. Regulatory approval - demanding pathway for combination medical devices (implant + digital health software)
5. Cost - significantly more expensive than conventional implants; cost-effectiveness unproven long-term
6. MRI compatibility - metallic and electronic components may limit postoperative MRI use

FUTURE DIRECTIONS (1 mark)

• Bioresorbable smart implants for fracture fixation that degrade after healing while transmitting data during active healing phase
• AI-integrated dashboards that synthesise implant data with wearable device data for holistic joint health monitoring
• Drug-eluting smart implants that release antibiotics or anti-inflammatory agents on demand when sensor detects early infection signals
• Closed-loop smart implants - fully autonomous: sensor detects problem, microprocessor responds, actuator adjusts stiffness or releases drug

DIAGRAM TO DRAW

Tibial component → Embedded pressure sensor → Wireless transmitter → External receiver/smartphone → Surgeon dashboard