MAKO Muscle-Sparing Total Knee Replacement
The MAKO Muscle-Sparing Total Knee is a robotic-arm assisted knee replacement that uses a subvastus approach — going underneath the quadriceps muscle rather than cutting through it. This preserves the muscle that straightens your knee, resulting in a faster, less painful recovery.
Dr. Lupo is the only surgeon in the Erie region performing this technique. Patients travel from over two hours away specifically for this procedure.
Why the MAKO Muscle-Sparing Approach Matters
In a traditional knee replacement, the surgeon cuts through the quadriceps tendon or vastus medialis muscle to access the knee joint. This is the muscle responsible for straightening your knee — critical for walking, climbing stairs, and getting out of a chair. Cutting through it means weeks of healing before you can use it normally again.
Dr. Lupo's enhanced medial oblique modified subvastus approach works around the quadriceps muscle rather than through it. This is a technique he has developed and refined specifically for robotic-arm assisted surgery, combining muscle-sparing principles with advanced robotic precision for superior patient outcomes.
Combined with robotic guidance that ensures optimal implant positioning within fractions of a millimeter, this technique delivers measurably better early outcomes:
Typical Recovery Timeline
How Robotic-Arm Assisted Knee Surgery Works
A personalized, CT-based surgical plan guides the robotic arm for unmatched precision in every knee replacement.
3D Planning
A CT scan creates a detailed 3D model of your unique knee anatomy. Dr. Lupo plans the exact position, size, and alignment of your implant before you ever enter the operating room.
Robotic Guidance
During surgery, the robotic arm provides real-time feedback and haptic boundaries. It guides Dr. Lupo's hands with sub-millimeter accuracy while he controls every movement.
Precision Placement
The implant is positioned exactly as planned — within fractions of a millimeter. This precision means better alignment, more natural movement, and longer implant life.
Why Robotics + Muscle-Sparing Produces Better Outcomes
It's not just the approach. It's not just the robot. It's the combination of both — minimizing trauma while maximizing precision — that delivers superior results.
55% Less Pain
Robotic-arm assisted patients reported a 55.4% lower median pain score compared to manual surgery patients from day 1 through week 8.
Source: Journal of Arthroplasty
Faster Quadriceps Recovery
The subvastus approach preserves the quadriceps mechanism, resulting in faster return of muscle strength and earlier independence — particularly in patients in their 60s.
Source: Annals of Medicine and Surgery, 2021
Higher Forgotten Joint Score
Robotic-assisted knee replacement patients report higher Forgotten Joint Scores — meaning they literally forget they have an artificial knee. The joint feels that natural.
Source: Knee Surgery, Sports Traumatology, Arthroscopy, 2023
26% Shorter Hospital Stay
Mako robotic TKA was associated with a 26% reduction in length of hospital stay, less need for in-patient physical therapy, and improved early functional recovery.
Source: Bone & Joint Journal, 2018
Less Opioid Use
Patients who underwent robotic-assisted TKA had lower opioid consumption at 90 days, 6 months, and 1 year compared to conventional surgery patients.
Source: Arthroplasty Today, 2020
Reduced Tissue Damage
Haptic-guided robotic boundaries protect surrounding bone and soft tissue during surgery, resulting in measurably less iatrogenic damage than manual techniques.
Source: Surgical Technology International, 2017
The Enhanced Robotic Workflow Difference
Dr. Lupo uses an enhanced robotic workflow that captures more data points and provides more information for accurately positioned implant plans. The vast majority of robotic surgeons use the express workflow, which provides less data. More data means better planning, better positioning, and better outcomes for you.
Robotic Partial Knee Replacement
When arthritis affects only one compartment of the knee, a partial (unicompartmental) knee replacement preserves healthy bone, cartilage, and ligaments. Robotic guidance ensures the partial implant is positioned with the same precision as a total replacement, maximizing longevity and natural feel.
Traditional vs. Muscle-Sparing Robotic Approach
Traditional Approach
- Cuts through quadriceps muscle
- Manual cutting guides
- Surgeon estimates alignment
- More post-operative pain
- Slower quad recovery (6–12 weeks)
- 2–3 day hospital stay typical
Dr. Lupo's Approach
- Preserves quadriceps muscle completely
- Robotic-arm guided precision
- CT-planned, sub-millimeter accuracy
- Significantly less pain
- Rapid quad strength return (2–4 weeks)
- 95% of patients go home the same day
The subvastus (muscle-sparing) approach has been validated in peer-reviewed literature as providing faster recovery and less pain compared to traditional medial parapatellar approaches.
Knee Replacement FAQ
What is the subvastus (muscle-sparing) approach?
The subvastus approach is a surgical technique for total knee replacement that accesses the knee joint from beneath the vastus medialis muscle rather than cutting through it. This preserves the quadriceps mechanism, which is responsible for straightening your knee. Because the muscle stays intact, patients typically experience less pain and faster recovery of knee function compared to traditional approaches.
How is robotic-arm assisted surgery different from traditional knee replacement?
In traditional knee replacement, the surgeon uses manual cutting guides to position the implant. With robotic-arm assisted surgery, a CT scan creates a 3D model of your knee before surgery. The surgeon plans the exact implant position on this model, and during surgery, the robotic arm provides real-time guidance and haptic boundaries to ensure the plan is executed with sub-millimeter accuracy.
Am I a candidate for muscle-sparing robotic knee replacement?
Most patients with knee arthritis who are candidates for total knee replacement can benefit from the muscle-sparing robotic approach. During your consultation, Dr. Lupo will evaluate your specific anatomy, the severity of your arthritis, and your overall health to determine the best surgical plan for you.
How long will I be in the hospital?
95% of Dr. Lupo's patients go home the same day. You are fully weight-bearing immediately and will do stairs before you leave the hospital. You will initially use a walking aid — not because you can't walk, but to rest the muscles around your knee as they heal. Most patients are off all walking aids within 1 to 4 weeks.
What is the difference between this approach and branded knee replacement programs?
Some surgeons pay an exorbitant amount of money in licensing fees to use trademarked names for their knee replacement marketing. Dr. Lupo performs an enhanced medial oblique modified subvastus approach that he has developed specifically to work with robotic-arm assisted technology. This is a technique he has refined over years of practice for superior patient outcomes. He further enhances his results with an advanced robotic workflow that provides more data and information for accurately positioned implant plans, as opposed to the express workflow used by the vast majority of robotic surgeons. The focus is on surgical innovation and outcomes, not marketing trademarks.
How long does the implant last?
Modern knee implants are designed to last 20–25 years or more. The precision of robotic-arm assisted placement may extend implant longevity by ensuring optimal alignment and reducing abnormal wear patterns.
Evidence-Based: Why This Approach Works
Every claim on this page is backed by peer-reviewed research. Here are the key findings — with links to the full evidence.
The Subvastus Approach: Faster Recovery, Less Pain, Better Function
A meta-analysis of 20 randomized trials (1,893 knees) confirms the subvastus approach delivers 47% less pain at 1 week, straight-leg raise 3 days earlier, and faster return to function compared to the standard approach that cuts through the quadriceps. A 10-year follow-up shows these benefits are durable.
MAKO Robotic Precision: Sub-Degree Accuracy for Longer-Lasting Results
The MAKO robotic arm uses a CT-based 3D model of your specific knee anatomy to plan and execute implant placement. Haptic boundaries prevent deviation from the surgical plan, achieving alignment accuracy within 1 degree. This precision means better ligament balancing, more natural knee feel, and potentially longer implant life.
Functional Alignment: Positioned for YOUR Body, Not a Generic Template
Traditional knee replacement forces every patient into the same mechanical axis. MAKO's functional alignment uses 3D CT planning + Digital Tensioner data to position the implant for your unique ligament balance — so the knee feels like yours, not someone else's. A matched study of 128 MAKO knees shows significantly better outcomes.
Functional Alignment: Your Knee, Positioned for Your Body
Traditional knee replacement forces every patient into the same generic alignment. MAKO's functional alignment positions the implant to match your unique ligament balance — so the knee feels like yours, not someone else's.
What Is Functional Alignment?
For decades, surgeons aligned every knee replacement to a single "mechanical axis" — a straight line from hip to ankle. This one-size-fits-all approach often requires cutting ligaments to make your knee fit the implant, and up to 20% of patients remain dissatisfied.
Functional alignment flips this concept: instead of forcing your knee to fit the implant, the implant is positioned to fit your knee's natural ligament balance. MAKO's Digital Tensioner objectively measures your medial and lateral ligament tension in real-time, then the 3D plan adjusts bone cuts to preserve your native soft tissue envelope — without releases.
Why This Is Only Possible with MAKO
Functional alignment is a 3D process — it adjusts implant position in the sagittal, transverse, and coronal planes simultaneously. This cannot be achieved with 2D manual cutting guides, fluoroscopy, or non-CT-based systems.
What the Research Shows: Functional vs. Mechanical Alignment with MAKO
of functional alignment patients report no residual symptoms (vs. 58% mechanical)
less instability with functional alignment (6.4% vs. 21.9%)
higher Forgotten Joint Score — the knee feels more natural
In a matched study of 128 MAKO knee replacements, functional alignment produced significantly better scores on every patient-reported outcome measure — Forgotten Joint Score (p=0.034), Oxford Knee Score (p=0.027), and Knee Society Score (p=0.02) — all without requiring any ligament releases.
Source: Michaud et al., SICOT Journal, 2024 | Bone & Joint Open, 2025 (22 studies, 3,738 TKAs) | Australian Orthopaedic Association Registry, 2024
MAKO: The Only Robotic System Proven in the Australian Registry
In the 2024 Australian Orthopaedic Association National Joint Replacement Registry — the world's largest joint registry — MAKO was the only robotic system to demonstrate a statistically significant improvement in revision rates compared to manual surgery. At 6 years, MAKO showed a 19% relative improvement in survivorship (30% when implanted with a patella). No other robotic system achieved this distinction.
Find Out If You're a Candidate
Schedule a consultation to discuss your knee pain and learn whether robotic-arm assisted, muscle-sparing knee replacement is right for you.