Specialty

Knee Arthritis: Osteoarthritis, Rheumatoid & Post-Traumatic

Sub-specialty evaluation and treatment of all three forms of knee arthritis — from structured non-surgical care and biologic injections through joint-preserving osteotomy, the MISHA implantable shock absorber, and partial or total knee replacement (Mako robotic-assisted) when appropriate. With Dr. Sabrina Strickland at the Hospital for Special Surgery in New York.

Medically reviewed by Dr. Sabrina Strickland, MD — Orthopedic Surgeon at the Hospital for Special Surgery in New York. View full bio →
Where
Hospital for Special Surgery, NYC · satellite office in Stamford, CT
Patients We See
NY, NJ, CT, and out-of-state patients across the full arthritis spectrum — non-surgical through revision
Philosophy
Joint preservation when appropriate — replacement when necessary
Overview

Three distinct conditions are grouped under "knee arthritis." Osteoarthritis (OA) is mechanical wear-and-tear cartilage thinning. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that attacks the joint and is co-managed with rheumatology. Post-traumatic arthritis develops months to decades after a knee injury (ACL tear, meniscus injury, intra-articular fracture, or prior surgery) and behaves like OA but in a younger, often more active patient. Treatment is matched to the type, distribution, and severity: structured PT, weight optimization, NSAIDs, and selective injections (cortisone, hyaluronic acid, PRP, BMAC) for first-line care; joint-preserving surgery — osteotomy, the MISHA implantable shock absorber, cartilage repair — for selected patients with isolated compartment disease; and partial or total knee replacement (Mako robotic-assisted when indicated) for end-stage arthritis. Dr. Sabrina Strickland evaluates these patients across the full spectrum at the Hospital for Special Surgery in New York and tailors the plan to the individual — with a sub-specialty interest in joint preservation before replacement.

"You have arthritis" is one of the most common diagnoses delivered in an orthopedic office, and one of the most often misunderstood. Arthritis is not a single disease — it is the end-stage of several different processes that can damage the same joint. Treatment, prognosis, and the right next step depend on which kind of arthritis you have, where in the knee it is, how much it is limiting you, and how much native joint there is left to preserve. The goal of this page is to give you a clear framework for understanding which of the three main types of knee arthritis you may have, what the non-surgical options actually are (and what they actually do), what joint-preserving options exist, and when knee replacement is — and is not — the right answer.

This page covers the three types of arthritis and how they differ; how arthritis feels and is diagnosed; the non-surgical treatment ladder and the orthobiologic injections; joint preservation (osteotomy, MISHA, cartilage repair) before replacement; partial vs. total knee replacement and Mako robotic-assisted technique; special considerations for rheumatoid and post-traumatic arthritis; prehabilitation and what to expect; insurance and cost; honest framing of emerging treatments and ongoing research; and when to seek a sub-specialty second opinion. For closely related procedures, see joint preservation and osteotomy for HTO and DFO, MACI and cartilage transplantation for focal cartilage defects, patellofemoral arthritis for kneecap-specific disease, meniscal surgery in arthritic knees, Mako robotic-assisted partial and total knee replacement, and PRP and regenerative medicine for orthobiologic injection details.

The Three Types of Knee Arthritis

Osteoarthritis (OA)

The most common type. Cartilage thins from a combination of age, genetics, alignment, and load. Often begins in the 40s, 50s, or 60s. Typically affects the medial compartment first in patients with varus alignment, the lateral in valgus, or the patellofemoral compartment in patients with kneecap maltracking. Progressive over years.

Rheumatoid Arthritis (RA)

An inflammatory autoimmune disease in which the body attacks the joint (synovium). Typically affects multiple joints symmetrically, with prolonged morning stiffness, fatigue, and systemic features. Co-managed with rheumatology — surgical care addresses joint damage that has already occurred and is coordinated with the medical regimen.

Post-Traumatic Arthritis

Develops months to decades after a knee injury — ACL tear, meniscus tear, intra-articular fracture, or prior knee surgery. Behaves like OA but in a younger, often more active patient. Joint-preserving options (osteotomy, MISHA, cartilage repair) are particularly relevant in this group.

The distinction matters because the treatment plan looks different for each. OA is approached compartment-by-compartment with mechanical solutions (offload, preserve, replace). RA is primarily a medical disease that may also need surgical care for damaged joints. Post-traumatic arthritis sits closest to OA in its mechanical management but is more likely to land in the joint-preservation conversation because of patient age and activity level.

How Knee Arthritis Feels

Patients describe arthritis pain in surprisingly consistent terms across the three types — though the rhythm differs:

  • A deep aching pain in the joint, often worse at the end of the day or after activity
  • Stiffness in the morning or after sitting. RA stiffness typically lasts longer — over an hour — while OA stiffness usually loosens within 15–30 minutes once the joint gets moving
  • Pain with activity — walking, stairs, getting up from a chair, prolonged standing, descending hills
  • Swelling that comes and goes, particularly after activity flares
  • Reduced range of motion — often loss of full extension or full deep flexion
  • Crepitus — clicking or grinding with motion
  • Bowing of the leg in advanced medial-compartment OA, or knock-knee deformity in advanced lateral-compartment OA
  • Buckling or "giving way" — usually from quadriceps inhibition rather than true ligamentous instability
  • Night pain in advanced disease — pain that wakes the patient and disrupts sleep
  • Gait changes — a painful limp, shorter stance phase on the affected side, or guarding that the patient does not consciously recognize

Symptoms typically progress over years, not weeks, with periods of relative stability interrupted by flares. A sudden change — a new mechanical catching, locking, or rapid swelling — deserves imaging and may indicate a new mechanical problem on top of underlying arthritis.

Who Develops Each Type

Osteoarthritis

OA is driven by some combination of age, genetics, alignment, and load. A 60-year-old with bowed alignment, a labor-intensive job, and a body weight 30 pounds over baseline is at high risk. So is a younger patient with congenital varus, repeated impact loading from sport, and family history. OA is less about a single cause and more about cumulative load on a particular compartment over years.

Rheumatoid Arthritis

RA is fundamentally an autoimmune disease. The body's immune system mistakenly attacks the synovial lining of joints, producing inflammation that destroys cartilage and bone. RA typically affects multiple joints symmetrically, often involves the hands and wrists prominently, and is associated with positive serology (rheumatoid factor, anti-CCP) and elevated inflammatory markers. RA is diagnosed and managed primarily by a rheumatologist; orthopedic care addresses the structural damage that has already occurred.

Post-Traumatic Arthritis

Post-traumatic arthritis develops in a knee that has been previously injured. Common predecessors include ACL tear (particularly when meniscus is also injured), meniscectomy, intra-articular fracture (tibial plateau, distal femur), patellar dislocation with osteochondral injury, and prior knee surgery. The mechanical biology is OA-like — cartilage thinning, subchondral changes, osteophytes — but the population is younger and more active, which is precisely the population where joint-preserving options (osteotomy, MISHA, cartilage repair) deserve careful consideration. For more on the relationship between ACL injury and arthritis risk, see ACL surgery: what raises arthritis risk?.

How the Diagnosis Is Made

History and Physical Exam

Pain pattern (location, character, time course), prior knee injuries or surgeries, family history of arthritis, systemic symptoms (morning stiffness duration, fatigue, other joint involvement) that may suggest inflammatory arthritis, current activity level, body weight, and what has and has not been tried. The exam includes range of motion, alignment in standing, gait, joint-line tenderness, effusion assessment, ligamentous stability, patellar tracking, and a sense of which compartment is the dominant problem.

Imaging

  • Standing weight-bearing x-rays — the cornerstone of arthritis diagnosis. Reveal joint-space narrowing (the radiographic hallmark of cartilage loss), osteophytes, subchondral sclerosis, and subchondral cysts. Standing films are essential because non-weight-bearing films underestimate joint-space loss
  • Long-leg standing alignment films — quantify the mechanical axis. Required when osteotomy or partial replacement is being considered
  • Merchant or skyline view — assesses the patellofemoral compartment
  • MRI — not always needed for end-stage arthritis, but useful for evaluating cartilage detail in earlier disease, assessing the meniscus, ruling out a focal cartilage defect amenable to repair, and looking for a co-existing mechanical problem
  • Laboratory workup — rheumatologic labs (RF, anti-CCP, ESR, CRP, ANA) when inflammatory arthritis is suspected. RA is fundamentally a medical diagnosis

The Treatment Ladder

Dr. Strickland's practice spans the entire knee-arthritis treatment spectrum — from first-line conservative care to joint replacement — with a sub-specialty interest in joint preservation before replacement. The ladder below is the sequence most patients move through over time, but the right step for a given patient depends on the type, stage, and distribution of disease, the patient's age and goals, and what has already been tried.

StepWhenWhat it addresses
Lifestyle & PTFirst-lineWeight optimization, quadriceps and hip strength, low-impact substitution, activity modification
MedicationsFirst-lineNSAIDs (oral and topical), acetaminophen for additional analgesia
BracingSelectiveOffloader brace for unicompartmental OA with correctable alignment
InjectionsSelectiveCortisone, hyaluronic acid, PRP, BMAC
Joint preservationYounger / active patients with isolated diseaseOsteotomy (HTO/DFO), MISHA, cartilage repair (MACI/OATS)
Partial replacement (UKA)Single-compartment end-stage OAResurface only the worn compartment; preserve native ligaments
Total replacement (TKA)Multi-compartment end-stage OA, severe deformityResurface all three compartments
RevisionFailed prior replacementAddress loosening, instability, infection, malalignment

The order of operations in arthritis is not rigid. A patient with an isolated focal cartilage defect on MRI may benefit more from MACI than from another round of injections. A 55-year-old with isolated medial compartment OA, varus alignment, and high activity demands may benefit more from HTO or MISHA than from progression along the injection ladder. The point of the ladder is to give patients a clear framework — not to force every patient through every rung.

Non-Surgical First-Line Care

The vast majority of knee arthritis patients live with their arthritis for years before reaching a surgical decision. Effective non-surgical care can preserve quality of life and delay or avoid surgery in many patients.

1

Activity modification and weight optimization

Substitute lower-impact activities (cycling, swimming, elliptical, walking on level ground) for higher-impact ones. Each pound of body weight loads the knee 4–6 times over with each stair step — meaningful weight loss is one of the highest-leverage interventions in OA.

2

Structured physical therapy

Quadriceps and hip-stabilizer strengthening, range-of-motion preservation, gait training, and proprioception. Strong quadriceps offload the joint and reduce pain in OA. The most under-executed step in arthritis care.

3

NSAIDs and topical agents

Oral NSAIDs (ibuprofen, naproxen, celecoxib) for inflammatory control during flares when not contraindicated. Topical NSAIDs (diclofenac gel) for localized symptom relief with fewer systemic effects. Acetaminophen for additional analgesia.

4

Bracing

An offloader brace can shift load away from a worn medial or lateral compartment and provide meaningful symptom relief in selected patients with unicompartmental OA and good alignment correction with the brace on.

5

Selective injection therapy

Cortisone for flares, hyaluronic acid for sustained symptom relief in selected patients, PRP and BMAC for biologic treatment for patients seeking to delay further intervention. Detailed in the next section.

6

Sleep, stress, and overall health

Sleep quality, stress, smoking, and overall metabolic health all influence pain perception and joint inflammation. These are not "extras" — they often distinguish patients who do well non-operatively from those who progress quickly to surgery.

Orthobiologic Injections Explained

InjectionWhat it isBest forTypical duration
CortisoneAnti-inflammatory steroidAcute flares, end-stage arthritis with inflammatory componentWeeks to a few months
Hyaluronic acid (viscosupplementation)Joint-lubricant supplement (Synvisc, Euflexxa, Orthovisc, others)Mild to moderate OA in selected patientsSeveral months in responders
PRP (platelet-rich plasma)Concentrated platelets from your own blood; delivers growth factorsMild to moderate OA, biologic treatment for patients seeking to delay further interventionSeveral months to a year in responders
BMAC (bone marrow aspirate concentrate)Bone marrow drawn from the iliac crest, concentrated, and injected. Contains stem-cell-rich fractionSelected joint-preservation candidates with mild to moderate diseaseMonths to a year in responders

Important caveats: none of these injections regrow cartilage in any clinically meaningful way that has been demonstrated in well-controlled human studies. What well-selected patients can get is meaningful symptom relief that delays the need for further intervention. Response rates are higher in earlier disease and in patients without significant alignment issues. The right injection is matched to the patient and the stage of disease — not chosen by patient request alone. For more detail on PRP and stem-cell options, see PRP and regenerative medicine.

Joint Preservation Before Replacement

For patients with isolated compartment arthritis, intact ligaments, and good range of motion — particularly younger or more active patients — joint-preserving surgery can delay or sometimes avoid joint replacement entirely. This is Dr. Strickland's sub-specialty differentiator: she sees patients across the whole arthritis spectrum but actively pursues joint preservation when it is the right answer rather than defaulting to replacement.

Osteotomy (HTO and DFO)

High tibial osteotomy (HTO) and distal femoral osteotomy (DFO) are controlled cuts and repositions of the tibia or femur that shift the mechanical axis of the leg from the worn compartment toward the healthy one. HTO is used for medial compartment arthritis with varus alignment; DFO is used for lateral compartment arthritis with valgus alignment. Best in younger, active patients who want to delay or avoid replacement. Recovery is several months for return to most activity. See joint preservation and osteotomy for the full procedure walk-through.

Cartilage Repair

For focal cartilage defects (not diffuse arthritis), cartilage-restoration procedures — MACI, OATS, or osteochondral allograft — can resurface a defined area of damage. These are not solutions for end-stage diffuse arthritis but are powerful tools for the right patient with a focal lesion in an otherwise preserved joint. Many patients with post-traumatic arthritis have a focal lesion that drives most of their symptoms and that responds well to cartilage repair. See cartilage transplantation (OATS & allograft) for details.

Patellofemoral arthritis

Arthritis isolated to the patellofemoral compartment (the front of the knee, behind the kneecap) has its own treatment considerations. Patellofemoral OA can sometimes be addressed with cartilage repair, with patellofemoral-specific partial replacement, or with realignment procedures — rather than total knee replacement. For the dedicated discussion, see patellar pain and patellofemoral arthritis.

Arthroscopy in the arthritic knee

Arthroscopy is not a treatment for arthritis itself, but it can address mechanical symptoms in an arthritic knee — loose-body removal, debridement of a torn meniscus contributing to mechanical catching — in carefully selected cases. See meniscal tear surgery for how meniscus repair vs. partial meniscectomy fits in OA-prone knees.

The MISHA Implantable Shock Absorber

The MISHA Knee System (Moximed) is an FDA-approved implantable shock absorber for medial-compartment knee osteoarthritis. It is placed outside the joint, between the femur and tibia on the medial side, where it absorbs and redistributes load away from the worn medial compartment. MISHA does not violate the joint surface, does not remove bone the way an osteotomy does, and is reversible — it can be removed if a patient ultimately progresses to joint replacement. For background on the system itself, see the MISHA Knee System overview.

MISHA is one of several joint-preserving alternatives for patients who:

  • Have medial compartment osteoarthritis as the dominant problem
  • Are not yet ready for partial or total knee replacement — either because of age, activity level, or personal preference
  • Want to preserve their native joint and keep replacement as a future option
  • Meet the candidacy criteria on imaging and exam

Whether MISHA is appropriate depends on the specific anatomy, alignment, and goals of the individual patient and is reviewed at consultation alongside the alternatives (HTO, partial replacement, continued non-operative care).

Partial Knee Replacement (UKA)

Partial (unicompartmental) knee replacement resurfaces only the worn compartment of the knee — medial, lateral, or patellofemoral — while preserving the other compartments and both cruciate ligaments. For the right patient (isolated compartment disease, intact ligaments, minimal disease elsewhere), partial replacement provides a more "natural" feeling knee for many patients and a faster recovery than total knee replacement. Some patients with bilateral isolated medial compartment disease are candidates for double partial knee replacements; for one example, see this discussion of double partial knee replacements.

Partial replacement is technically more demanding than total replacement — precision matters more because the implant has to integrate with intact native compartments and ligaments. This is one of the procedures where Mako robotic-assisted surgery has a particularly clear technical contribution.

Total Knee Replacement (TKA)

Total knee replacement resurfaces all three compartments of the knee. It is the right answer for advanced multi-compartment arthritis, severe deformity, ligamentous deficiency that cannot be addressed with a partial, and revision settings. Modern TKA implants and techniques have excellent long-term durability when matched to the right patient.

For patients preparing for knee replacement, see Dr. Strickland's patient education on what to do before knee replacement surgery and what to worry about when undergoing a knee replacement — structured walkthroughs of the realistic expectations, timeline, and trade-offs.

Robotic-Assisted Knee Replacement

Mako robotic-assisted surgery enables sub-millimeter accuracy in implant placement and ligament balancing. The surgeon plans the operation on a 3D model of the patient's specific anatomy, and the robotic arm helps execute the bone cuts and implant positioning within that plan. The benefit is most clear in partial knee replacement, where precision matters disproportionately. In total knee replacement, robotic assistance helps with alignment and balance.

Robotic assistance is a tool, not a substitute for surgeon experience or patient selection — the long-term outcome literature is still maturing. For the dedicated walk-through, including what to expect on a Mako case, see Mako robotic-assisted surgery.

Rheumatoid Arthritis — Special Considerations

Rheumatoid arthritis is fundamentally a medical disease — the foundation of treatment is rheumatologic management with disease-modifying antirheumatic drugs (DMARDs) such as methotrexate, biologics (TNF inhibitors and others), and inflammation-control regimens. Surgical care for the knee in RA addresses joint damage that has already occurred and is coordinated with the rheumatologist's medical regimen.

Several practical points for RA patients facing knee surgery:

  • Disease control before elective surgery — well-controlled RA is associated with better surgical outcomes and lower complication rates. Active flare is generally not the time for elective replacement
  • Medication management around surgery — many DMARDs and biologics need to be held briefly around the surgical date to reduce infection risk; this is coordinated with the rheumatologist using established perioperative guidelines
  • Soft-tissue and bone considerations — chronic inflammation in RA can produce thinner soft-tissue envelopes and softer bone, which influences technique and implant choice
  • Multiple-joint planning — RA often involves several joints, and the order of operations may need to be considered (lower extremity often before upper extremity if both need work, etc.)
  • Joint replacement remains highly successful in RA when timed appropriately and when systemic disease is well controlled

Post-Traumatic Arthritis — Special Considerations

Post-traumatic arthritis presents in a younger, often more active patient than typical OA. The same compartment-by-compartment mechanical principles apply, but the planning is different:

  • Often single-compartment — particularly the medial compartment after meniscectomy or ACL injury. This makes joint-preservation and partial replacement more often relevant than in older OA
  • Prior surgical hardware — ACL graft tunnels, ORIF hardware from a prior fracture, or other implants may need to be considered or removed in the surgical plan
  • Alignment — trauma to the lateral tibial plateau, malunion of a prior fracture, or chronic ACL deficiency can produce alignment issues that are part of the disease and need to be addressed
  • Activity goals — younger post-traumatic OA patients often want to preserve high-impact activity, which favors joint-preserving options when feasible
  • The young-patient tradeoff — replacement at a younger age is highly successful but more likely to need revision later in life simply because the patient lives longer with the implant

For the link between ACL injury and arthritis risk, see ACL surgery: what raises arthritis risk? For the broader sport-and-knee context, see Dr. Strickland's discussion of knee injuries, arthritis, and skiing.

Prehabilitation

Whether the surgery is osteotomy, MISHA, partial knee replacement, or total knee replacement, what happens before the operation matters. Patients who arrive at surgery with full or near-full range of motion, minimal swelling, and good quadriceps activation have substantially better post-operative outcomes than patients who arrive with a stiff, swollen knee and inhibited quadriceps. Prehabilitation includes:

  • Range of motion preservation — particularly full extension
  • Effusion control
  • Quadriceps activation — early termination of quadriceps shutdown reduces post-op recovery time
  • Weight optimization — even modest pre-op weight loss reduces complication risk and improves the post-op trajectory
  • Cardiovascular conditioning in patients who will need general or spinal anesthesia
  • Education on the post-operative protocol so the patient hits the ground running
  • Medical optimization — diabetes control, smoking cessation, dental clearance, and other modifiable factors that influence infection risk

For patients with rheumatoid arthritis, prehabilitation also includes coordination with the rheumatologist on biologic-medication timing. For more, see what to do before knee replacement surgery.

What to Expect on Surgery Day

Specifics vary by procedure (joint-preserving surgery, MISHA, partial replacement, total replacement) and your protocol is individualized at consultation. The general patient experience for knee replacement is:

  • Arrival and pre-op — you arrive a couple of hours before the procedure for intake, change into a gown, and meet the anesthesia team
  • Anesthesia consultation — for Dr. Strickland's knee replacements, the plan is spinal anesthesia with sedation combined with a periarticular block placed around the knee joint during surgery. Dr. Strickland does not use general anesthesia or femoral/adductor-canal nerve blocks. The periarticular block helps reduce post-operative pain during the first day after surgery and is part of an opioid-sparing pain protocol.
  • Surgery — the procedure itself typically takes 1 to 2 hours depending on the operation and any concurrent work
  • Recovery room — you wake up in the recovery area; for outpatient cases, physical therapy starts the same day with assisted weight-bearing
  • Going home or admitting — many partial and total knee replacements are now performed on an outpatient or short-stay basis; some patients (older patients, those with significant comorbidities, those without home support) admit overnight or for 1–2 days
  • First 48 hours — ice, elevation, prescribed medications, gentle motion as instructed. The first week's focus is effusion control, motion, and quadriceps activation

The block typically wears off over the first 12 to 24 hours, during which the leg is numb and weight-bearing requires the brace and walker because the leg is not protecting itself normally. This is expected and is the trade-off for the lower pain levels in that first day.

Recovery Timelines

Recovery differs by procedure. The timelines below are typical — your individual timeline depends on your starting point, the specific procedure, your adherence to PT, and your goals.

ProcedureWalker / caneDrivingMost daily activityFull recovery
Cortisone / HA / PRPNoneSame dayDaysN/A
Arthroscopy / debridementFew days1–2 weeks2–4 weeks2–3 months
HTO / DFO osteotomy4–6 weeks protected6–8 weeks3–4 months6–9 months
MISHA implantFew weeks2–4 weeks4–6 weeks3–6 months
Partial knee replacement (UKA)1–2 weeks2–4 weeks4–6 weeks3–6 months
Total knee replacement (TKA)2–4 weeks4–6 weeks2–3 months9–12 months

Patients consistently underestimate the role of structured PT in recovery. Skipping or shortening PT does not save time — it almost always extends the recovery and increases the risk of stiffness, particularly after total knee replacement.

Risks of Knee Replacement

Knee replacement is a well-established surgery with predictable outcomes for most patients, but no surgery is risk-free. The risks reviewed at consultation include:

  • Infection — including periprosthetic joint infection. Uncommon (typically <1–2%) but a serious complication if it occurs. Modern protocols include preoperative skin decolonization, perioperative antibiotics, and stringent intraoperative protocols
  • Blood clot (DVT and pulmonary embolism) — risk is mitigated by early mobilization, mechanical compression, and individualized chemoprophylaxis
  • Joint stiffness — reduced by good prehabilitation, structured PT, and addressing any motion deficit early
  • Implant loosening or wear — over years to decades. Modern implants are designed to last 15–20+ years for most patients
  • Periprosthetic fracture — uncommon, more relevant in older patients with osteoporosis or after high-energy trauma
  • Persistent pain — a small subset of patients have ongoing knee pain after a technically successful replacement. Pre-existing chronic pain conditions, central sensitization, and patient-specific factors contribute
  • Need for revision — some patients require revision surgery years later. Younger and more active patients are statistically more likely to need revision in their lifetime simply because they live longer with the implant
  • Anesthesia-related risks — including nausea, allergic reactions, nerve irritation or injury from the block, and rare cardiac or respiratory complications

For the patient-facing walkthrough, see what to worry about when undergoing a knee replacement. The specific risk profile for your case depends on your age, weight, medical history, the type of arthritis, the procedure planned, and prior surgery on the knee.

Common Patient Concerns

The three concerns we hear most often before knee arthritis surgery, with honest answers:

"I'm too young for a knee replacement."

This is one of the more important conversations on this page. Many patients in their 40s and even 50s arrive having been told the same. The honest answer is that some patients in their 40s genuinely benefit from joint-preserving alternatives (HTO, DFO, MISHA, partial replacement) rather than total knee replacement — and some patients in their 40s or even 30s have arthritis advanced enough that partial or total replacement is the best answer despite their age. The right decision is made compartment-by-compartment with imaging in front of you, alignment films, an honest conversation about activity goals, and a clear walk-through of every option — not by age alone.

"How long will the implant actually last?"

Modern partial and total knee replacements are designed to last 15–20+ years for most patients. Implant longevity depends on patient factors (age at surgery, weight, activity level), implant design and materials, surgical technique (alignment and ligament balance), and ongoing factors over the years. Younger and more active patients are statistically more likely to need a revision in their lifetime simply because they live longer with the implant — which is part of why joint-preserving alternatives are particularly worth considering in younger patients.

"I'm scared of pain and of getting hooked on opioids."

Dr. Strickland's knee replacement protocol uses multimodal pain management — spinal anesthesia with sedation, a periarticular block placed around the knee joint during surgery to help reduce pain during the first day after surgery, scheduled non-opioid medications (acetaminophen and an anti-inflammatory unless contraindicated), ice, and elevation. Most patients use only a small number of opioid pills for breakthrough pain in the first few days, and many are off opioids entirely within the first week or two. The periarticular block and the multimodal approach are specifically designed to minimize the role of opioids in your recovery.

Insurance and Cost

Evaluation and treatment of knee arthritis — including imaging, injections, and surgical care when medically necessary — are covered by all major commercial insurance plans, Medicare, and most self-funded and union plans. Knee replacement, partial replacement, osteotomy, and cartilage repair are recognized medical-necessity procedures when the diagnosis and indication meet plan criteria. The variables that drive your specific out-of-pocket cost are:

  • Your plan's deductible and coinsurance — the structure of cost-sharing differs significantly between plans
  • In-network vs. out-of-network status — for the surgeon, the facility (Hospital for Special Surgery or affiliated outpatient surgery center), and the anesthesia group
  • The bundled vs. separate billing for the surgeon, facility, anesthesia, imaging, physical therapy, and any concurrent procedures
  • Coverage of specific biologics — cortisone is universally covered; hyaluronic acid is generally covered with prior authorization; PRP, BMAC, and other regenerative injections are not covered by commercial insurance and may be self-pay
  • MISHA, osteotomy, and joint replacement coverage — covered as medically necessary when criteria are met; we obtain pre-authorization where required

Before any procedure, our office verifies your benefits, obtains pre-authorization where required, and reviews the estimated out-of-pocket cost with you. If your plan doesn't cover a specific aspect, we discuss it openly before the procedure, not after.

For benefits verification or to discuss self-pay arrangements, call us at (646) 960-7227 or contact the office.

Emerging Treatments — Honest Framing

Knee arthritis is a high-interest research area, and patients regularly ask about treatments they have read about or seen on the news. None of the following are standard of care for knee arthritis — they are research-stage or early-clinical — but they are worth knowing about, and Dr. Strickland follows the evidence on each:

None of the above is offered or recommended as a substitute for evidence-based care today. The point of including them is that patients deserve a surgeon who reads the literature and gives an honest answer about what is research, what is investigational, and what is standard of care — rather than dismissing every new treatment patients ask about. For Dr. Strickland's broader research interests, see her research and publications.

When to Seek a Sub-Specialty Second Opinion

A sub-specialty second opinion in knee arthritis is particularly worth seeking when:

  • You have been told you need a total knee replacement but your imaging shows arthritis isolated to one compartment
  • You are young or active and want a clear answer on joint-preserving options before considering replacement
  • You have post-traumatic arthritis after a prior ACL, meniscus, or fracture surgery and want to understand whether osteotomy, MISHA, or cartilage repair fits your case
  • You have had a prior knee replacement that is not performing as expected and are facing revision
  • You have rheumatoid arthritis and need orthopedic care coordinated with your rheumatology regimen
  • You want a clear walk-through of all options — non-surgical, joint-preserving, partial, total — rather than a single recommendation
  • You are weighing a partial vs. total knee replacement and want a precise compartment-by-compartment assessment of your imaging
  • You have been considering biologic injections (PRP, BMAC) and want an honest assessment of what to realistically expect

Access & Office Locations

Dr. Strickland sees knee arthritis patients at two offices, both of which work with patients traveling in from outside the immediate area:

  • New York City (primary): Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, 2nd Floor, New York, NY 10021. On the Upper East Side, accessible from Manhattan, the outer boroughs, Long Island, Westchester, and northern New Jersey via the Queensboro and Triboro bridges and the FDR Drive. Phone: (646) 960-7227.
  • Stamford, CT (satellite): Stamford Chelsea Piers, 1 Blachley Road, Stamford, CT 06902 — convenient for patients in Fairfield County, lower Connecticut, and Westchester.

For patients traveling to New York from out of state for sub-specialty knee arthritis care, we coordinate consultation and surgery scheduling to minimize travel and align with imaging review and pre-operative work-up. Many out-of-state patients travel to HSS specifically for joint-preservation evaluation, MISHA candidacy, partial knee replacement, and joint replacement.

Frequently Asked Questions

Osteoarthritis (OA) is mechanical wear-and-tear cartilage thinning, often beginning in the 40s, 50s, or 60s, typically driven by some combination of age, genetics, alignment, and load. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease in which the body's own immune system attacks the joint lining (synovium), causing inflammation, cartilage destruction, and often involvement of multiple joints symmetrically. Post-traumatic arthritis develops months to decades after a knee injury (ACL tear, meniscus tear, intra-articular fracture, or prior surgery) and behaves like OA but in a younger, often more active patient.

Often, yes. Weight optimization, anti-inflammatory medications, structured exercise focused on quadriceps and hip stabilizer strengthening, cortisone injections, hyaluronic acid, PRP, BMAC (bone marrow aspirate concentrate), and joint-preserving surgery (osteotomy, MISHA implantable shock absorber, cartilage repair) can ease pain and delay replacement in selected patients. The right combination depends on the type and distribution of the arthritis, your alignment, your activity level, and how much your symptoms are limiting you.

Cortisone provides short-term anti-inflammatory relief and is most useful for flares. Hyaluronic acid (viscosupplementation) acts as a joint lubricant and can ease arthritic pain for several months in selected patients. PRP (platelet-rich plasma) uses your own concentrated platelets to deliver growth factors. BMAC (bone marrow aspirate concentrate) is a stem-cell-rich biologic preparation. None of these regrow cartilage in any clinically meaningful way, but well-selected patients can get meaningful symptom relief that delays the need for further intervention.

The MISHA Knee System (Moximed) is an FDA-approved implantable shock absorber for medial compartment knee osteoarthritis. It is placed outside the joint, between the femur and tibia on the medial side, where it absorbs and redistributes load away from the worn medial compartment. MISHA does not violate the joint surface, does not remove bone the way an osteotomy does, and is reversible — it can be removed if a patient ultimately progresses to joint replacement. It is one of several joint-preserving alternatives for patients who are not yet ready for partial or total knee replacement, who want to preserve their native joint, and who meet the candidacy criteria.

Partial (unicompartmental) knee replacement is appropriate when the arthritis is isolated to one compartment of the knee — most commonly the medial compartment, sometimes the lateral, and occasionally the patellofemoral compartment in isolation — with intact cruciate ligaments and minimal disease in the other compartments. For these patients, partial replacement preserves more native bone and ligament, gives a more "natural" feeling knee for many patients, and is associated with faster recovery than total knee replacement.

High tibial osteotomy (HTO) is a controlled cut and reposition of the upper tibia that shifts the mechanical axis of the leg from the worn compartment toward the healthy one. It is considered for younger, active patients with isolated medial compartment arthritis and varus (bow-legged) alignment, where the goal is to delay or avoid joint replacement by offloading the damaged side. Distal femoral osteotomy (DFO) does the equivalent for valgus alignment with lateral-compartment disease.

Modern partial and total knee replacements are designed to last 15 to 20+ years for most patients. Longevity depends on patient factors (age, weight, activity level), implant design, surgical technique (alignment and ligament balance), and adherence to activity guidance. Younger patients are statistically more likely to need a revision in their lifetime simply because they live longer with the implant — which is part of why joint-preserving alternatives are particularly worth considering in younger patients.

Risks include blood clot (DVT or pulmonary embolism), infection (including periprosthetic joint infection), joint stiffness, implant loosening or wear over time, periprosthetic fracture, ongoing pain in a small subset of patients, and the small possibility of needing revision surgery years later. These risks are weighed at consultation against the expected reduction in pain and improvement in function. Modern partial and total knee replacements have excellent long-term durability when matched to the right patient.

Rheumatoid arthritis is a systemic inflammatory disease that requires medical management by a rheumatologist — disease-modifying antirheumatic drugs (DMARDs), biologics, and inflammation-control regimens are the foundation of treatment. Surgical care for the knee in RA addresses joint damage that has already occurred and is coordinated with the rheumatologist's medical regimen. Many DMARDs and biologics need to be held briefly around the surgical date to reduce infection risk. Joint replacement remains highly successful in RA patients when timed appropriately and when systemic disease is well controlled.

Mako robotic-assisted surgery enables sub-millimeter accuracy in implant placement and ligament balancing. The benefit is most clear in partial knee replacement, where precision matters disproportionately because the implant has to integrate with intact native compartments and ligaments. In total knee replacement, robotic assistance helps with alignment and balance and may shorten the learning curve for newer techniques. Studies are still ongoing on long-term outcome differences. The most important factor in any knee replacement is patient selection and surgeon experience — the robot is a tool, not a substitute for either.

Related Specialty Care

For joint-preserving osteotomies, see joint preservation and osteotomy (HTO, DFO, TTO). For cartilage-restoration options for focal cartilage defects, see MACI cartilage repair and cartilage transplantation (OATS & allograft). For PRP and stem-cell injection details, see PRP and regenerative medicine. For partial and total knee replacement with sub-millimeter implant precision, see Mako robotic-assisted surgery. For patellofemoral arthritis behind the kneecap, see patellar pain and patellofemoral arthritis. For meniscal surgery in OA-prone knees, see meniscal tear surgery.

Medical Disclaimer. This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Surgical and non-surgical orthopedic care should always be discussed with a board-certified orthopedic surgeon who has reviewed your imaging, history, and physical examination. Individual outcomes vary based on diagnosis, type and stage of arthritis, anatomy, comorbidities, surgical or non-surgical approach selected, and adherence to rehabilitation. The general descriptions of anesthesia, pain protocols, and timelines on this page reflect typical knee-arthritis patient experience — your specific protocol is determined at consultation. Emerging and research-stage treatments referenced on this page are not standard of care and are not offered or recommended as substitutes for evidence-based treatment.

Discuss Your Knee Arthritis Options

If you have been told you need a knee replacement and want a sub-specialty second opinion on joint-preserving options — or you want a clear walk-through of every option from PT to replacement — bring your imaging to a consultation in NYC or Stamford, CT.

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