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FRACS · NZOA · ACC

Specialty 02 · The Knee

Knee.

Over 100 computer-navigated total knee replacements annually, plus robotic knee replacement, ACL reconstruction, arthroscopy, patella stabilisation, and high tibial osteotomy for younger patients.

On this page

5 conditions · Meniscal Tears · ACL Injuries · Knee Arthritis · Patella Instability · Worn Knee Replacement

7 procedures · Knee Arthroscopy · ACL Reconstruction · Knee Replacement · Robotic · Revision · Patella Stabilisation · High Tibial Osteotomy

Part I

Knee Conditions

Five common knee problems span the patient population from teenage athletes through to older adults with established arthritis.

Condition 01 / The Knee

Cartilage

Meniscal Tears

Tears of the knee's shock-absorbing cartilage

The meniscus is a C-shaped pad of cartilage inside the knee that distributes load and acts as a shock-absorber. There is one on each side of the joint — medial and lateral. Meniscal tears are among the most common knee injuries.

Types of tear

  • Vertical / longitudinal — along the length of the meniscus.
  • Horizontal / flap — splitting the meniscus through its thickness.
  • Radial — across the meniscus toward its inner edge.
  • Oblique — diagonal across the meniscus.
  • Bucket-handle — a vertical tear that displaces, locking the knee.
  • Complex — combination patterns.
  • Root tear — detachment of the meniscus from its bony attachment.

Symptoms

  • Pain on the side of the tear.
  • Swelling appearing within days of injury.
  • Catching or locking sensations.
  • Inability to fully straighten the knee (bucket-handle).
  • Episodes of instability or giving way.

Non-surgical treatment

Rest, ice, anti-inflammatories, physiotherapy and a low-impact exercise programme. Degenerative tears in arthritic knees are often best managed without surgery.

Surgical treatment

  • Meniscectomy — trimming the torn portion.
  • Meniscal repair — suturing the tear for healing potential.
  • Meniscal root repair — reattaching the meniscus to bone.

Degenerative tears may be managed with cortisone or hyaluronic acid injections, or with knee replacement when arthritis is the dominant problem.

Condition 02 / The Knee

Ligament injury

ACL Injuries

Anterior cruciate ligament rupture

The anterior cruciate ligament (ACL) runs from the femur to the tibia inside the knee. It prevents the tibia sliding forward and is critical for twisting and pivoting activities. Rupture causes instability.

Mechanism

Typically a twisting or pivoting injury, frequently in netball, rugby, football, or skiing. Patients often describe an audible pop, immediate pain, rapid swelling within hours, and a feeling of the knee giving way when attempting to pivot.

Diagnosis

Clinical examination is highly sensitive; MRI confirms the diagnosis and assesses any associated damage to meniscus, cartilage, or other ligaments.

Non-surgical management

  • Regain full range of motion first.
  • Quadriceps and hamstring strengthening.
  • Physiotherapy and gym-based rehabilitation over 3+ months.
  • Suitable for patients returning to non-pivoting activity.

Surgical management

ACL reconstruction is recommended for patients returning to pivoting sport, heavy manual work, or those with significant additional knee damage (meniscal injury, instability).

Condition 03 / The Knee

Patient education

Knee Arthritis

Cartilage degeneration of the knee joint

Knee arthritis describes the gradual loss of cartilage from the joint surfaces of the knee. As cartilage thins, the underlying bone is exposed; bone spurs (osteophytes) develop and the joint stiffens.

Symptoms

  • Localised knee pain on activity.
  • Sleep disturbance with progressive disease.
  • Limping with prolonged walking.
  • Morning stiffness and crepitus (grinding sensation).
  • Progressive bowing or knock-knee deformity.
  • Reduced walking distance.

Non-surgical treatment

  • Quadriceps strengthening and physiotherapy.
  • Activity modification — switching from high to low-impact exercise.
  • Weight optimisation.
  • Anti-inflammatories (NSAIDs) when appropriate.
  • Glucosamine — limited but acceptable evidence.
  • Hyaluronic acid injection — modest evidence for symptom relief.
  • Platelet-rich plasma (PRP) — limited evidence.

A note on stem cell therapy

Stem cell injections are widely marketed but the evidence base does not yet support routine use for knee arthritis. Patients should be cautious of high-cost offerings without published outcome data.

Surgical treatment

  • Total knee replacement (computer-navigated).
  • Partial (unicompartmental) knee replacement for single-compartment disease.
  • Patellofemoral replacement for isolated patellofemoral arthritis.
  • High tibial osteotomy for younger patients with partial-compartment disease and good alignment correction options.

Condition 04 / The Knee

Young adult / sports

Patella Instability

Recurrent dislocation of the kneecap

The patella (kneecap) sits in the trochlear groove on the front of the femur and is held in place by ligaments, the shape of the bones, and the pull of the quadriceps. Instability describes the kneecap slipping or dislocating — almost always outward.

Stability factors

  • Shape of the trochlear groove (shallow grooves predispose to instability).
  • Medial patello-femoral ligament (MPFL) integrity.
  • Quadriceps strength and balance — particularly the VMO.
  • Joint laxity (hypermobility).
  • Knee alignment (valgus / knock-knees).

Non-surgical treatment

After a first dislocation, 60–70% of patients heal without surgery. Initial management is a brace or splint, followed by physiotherapy focused on VMO strengthening, and taping for return to sport.

Diagnosis

X-rays, long-leg standing X-rays for alignment, and MRI to assess MPFL and cartilage. CT for trochlear groove geometry where surgery is considered.

Surgical treatment

  • Arthroscopy to remove loose bone or cartilage fragments after a first dislocation.
  • Open repair for large fragments.
  • Ligament reconstruction for recurrent instability (see Patella Stabilisation).

Condition 05 / The Knee

Revision pathway

Painful / Worn Knee Replacement

Investigation of a failed prior implant

A previously successful knee replacement that becomes painful warrants thorough investigation. Six common mechanisms account for most failures.

Mechanisms of failure

  • Loosening — repetitive stress causing components to lose their bond to bone.
  • Wear — debris from the polyethylene liner triggering an immune response and bone loss.
  • Infection — early surgical or late haematogenous spread.
  • Instability — ligament loosening over time.
  • Fracture — typically from a fall.
  • Patellofemoral pain — particularly where the kneecap was not resurfaced.

Investigation

  • X-rays compared with the original post-operative films.
  • CT for component orientation.
  • MRI (metal artefact reduction).
  • Bone scan and SPECT-CT for loosening or infection.
  • Ultrasound and blood tests where appropriate.

Treatment

Conservative monitoring suits patients with low-level symptoms and no progressive findings. Otherwise — revision knee replacement from a single-component swap to a full implant exchange.

Part II

Knee Procedures

Seven procedures span the spectrum of knee surgery — from arthroscopy and ACL reconstruction in young athletes to computer-navigated and robotic joint replacement.

Procedure 06 / The Knee

Keyhole

Knee Arthroscopy

Keyhole knee surgery

Knee arthroscopy is keyhole surgery performed through two to three small (1cm) incisions using a camera and specialised instruments. Most procedures are performed under general anaesthesia and patients go home the same day.

Conditions treated

  • Meniscal tears.
  • Cartilage damage and chondral defects.
  • Scar tissue and adhesions.
  • Loose bodies inside the knee.
  • Early arthritis with mechanical symptoms.
  • As part of ligament reconstruction.

Common procedures

  • Meniscectomy — trimming a torn meniscus.
  • Meniscal repair — suturing the meniscus.
  • Chondroplasty — debridement of damaged cartilage.
  • Microfracture — drilling small holes to stimulate cartilage healing.

Recovery

  • Same-day discharge.
  • Stitches reviewed and removed at 10 days.
  • Driving — 1 to 2 weeks.
  • Office work — 1 to 3 days.
  • Swelling typically present for 6 to 8 weeks.

Procedure 07 / The Knee

Ligament reconstruction

ACL Reconstruction

Replacement of the torn anterior cruciate ligament

ACL reconstruction replaces the torn ligament with a graft of tissue — usually taken from the patient's own hamstring or patellar tendon. The procedure is arthroscopic, with bone tunnels drilled to position the new ligament and endo-button fixation securing the graft.

Graft options

  • Hamstring graft — most common. Smaller scar; slightly higher re-injury risk in young pivoting athletes.
  • Patellar tendon graft — larger graft with bone block; lower re-injury risk; slightly longer recovery and risk of anterior knee pain.
  • Allograft (donor tissue) — reserved for revision surgery or multiple-ligament injuries.

Pre-surgery

Full knee motion is required before surgery — operating on a stiff knee predisposes to scar tissue and stiffness afterwards.

Phased recovery

  • 0–2 weeks — wound healing, full extension, walking.
  • 2–6 weeks — graduated weight-bearing, basic strengthening.
  • 6–12 weeks — closed-chain strengthening, balance.
  • 3–6 months — running progression and sport-specific drills.
  • 9–12 months — return to twisting and pivoting sport.
  • 12–18 months — full graft strength.

Graft healing

Bone tunnel healing is typically complete by 8 weeks; the graft itself remodels over 12 to 18 months. Re-rupture rate is approximately 5%.

Driving & work

Driving — typically 2–4 weeks depending on operated side. Office work — 1 week. Manual work — 6–12 weeks.

Procedure 08 / The Knee

Computer navigation

Total Knee Replacement

Computer-navigated TKR — Mr Gormack performs 100+ each year

Total knee replacement removes the damaged joint surfaces of the knee and replaces them with a prosthetic implant. Mr Gormack uses computer navigation on every primary case — confirming the precise position of the cutting guides during surgery for optimal alignment and balance.

The implant

  • Metal femoral component — covers the end of the femur.
  • Metal tibial component — covers the top of the tibia.
  • Highly cross-linked polyethylene liner — the bearing surface.
  • Patella resurfacing — selective, depending on kneecap condition.

Most components are cemented in place with PMMA bone cement; cementless fixation is used in select cases.

The procedure

The operation typically takes 90 minutes under spinal or general anaesthesia. Computer navigation tracks the alignment of femoral and tibial cuts to within a degree, ensuring the implant is balanced through the full range of motion.

Pre-surgery preparation

  • Cease smoking — improves wound healing and reduces complications.
  • Optimise diabetes and ensure dental health is up to date.
  • Weight optimisation.

Recovery

  • Standing the same day as surgery.
  • Crutches typically for 2–4 weeks.
  • Most patients off all aids by 6 weeks.
  • Full functional recovery by 6 months.

Risks & longevity

Infection, blood clot (DVT/PE), stiffness, ongoing pain (10–15% of patients), nerve injury and rare cardiac events. Modern implants commonly last 15–20 years with appropriate use.

Procedure 09 / The Knee

Robotic

Robotic Knee Replacement

Robotic-arm assisted precision arthroplasty

Robotic knee replacement uses a robotic arm to guide bone cuts with sub-millimetre precision. The plan is built from a CT scan before surgery; the robotic system enforces the plan intra-operatively while Mr Gormack retains full control of the procedure.

Benefits

  • Highly accurate implant positioning.
  • Reproducible soft-tissue balance through the full range of motion.
  • Minimised bone resection.
  • Suitable for both total and partial knee replacement.

Recovery

Recovery timeline mirrors the conventional total knee replacement pathway — standing the same day, crutches 2–4 weeks, full recovery 6 months.

Procedure 10 / The Knee

Complex reconstruction

Revision Knee Replacement

Re-doing a failed total knee replacement

Revision knee replacement re-does parts of a failed total knee replacement. The procedure removes the worn or failed components and inserts purpose-designed revision prostheses — often with metal augments and bone grafting where bone loss has occurred.

Indications

  • Loosening of components.
  • Wear of the polyethylene liner.
  • Infection.
  • Instability.
  • Periprosthetic fracture.
  • Persistent patellofemoral pain.

The procedure

Performed under spinal anaesthesia in most cases. Operative time ranges from 90 minutes to 4+ hours depending on the complexity of the reconstruction. Modern systems — for example the ATTUNE Revision Knee System — provide modular options for individual reconstruction needs.

Recovery

  • Hospital stay 2–7 nights.
  • Crutches for approximately 6 weeks.
  • Full recovery over several months.

Outcomes

The majority of patients experience favourable long-term pain relief and function following revision; risk profile is higher than primary replacement.

Procedure 11 / The Knee

Ligament reconstruction

Patella Stabilisation

MPFL reconstruction · Tibial tuberosity osteotomy

Patella stabilisation surgery prevents recurrent kneecap dislocation. Indicated after two to three dislocations, or following a single dislocation with cartilage or bone damage. Two techniques are used — chosen according to the underlying anatomical cause of instability.

MPFL Reconstruction

Reconstruction of the medial patello-femoral ligament using a hamstring tendon graft. Performed through three small incisions; bone anchors and screws secure the graft to the patella and femur. Designed for patients whose primary problem is a deficient MPFL.

Tibial Tuberosity Osteotomy

Repositioning the bony attachment of the patellar tendon (the tibial tuberosity) through a 5–8cm incision. The bone fragment is moved to better align the patella in its groove and fixed in place with 2–3 screws. Used where alignment is the primary issue.

Recovery

  • 6 weeks — reducing swelling, regaining motion, gradual loading.
  • Subsequent months — strengthening, return to running and sport.
  • Sport return — 4–6 months.

Success rate

90–95% of patients experience no further dislocation following surgery. Risks include re-dislocation, stiffness, fracture (osteotomy), and standard surgical risks.

Procedure 12 / The Knee

Joint-preserving

High Tibial Osteotomy

Realignment osteotomy for partial-compartment arthritis

High tibial osteotomy (HTO) realigns the leg to take load off an arthritic compartment of the knee. The technique is best suited to younger, active patients with arthritis confined to one compartment — typically medial — and good remaining cartilage on the other side.

Indication

  • Younger active patient.
  • Single-compartment (usually medial) arthritis.
  • Varus (bow-legged) alignment correctable by osteotomy.
  • Adequate range of motion preserved.

The procedure

A controlled bone cut is made in the upper tibia and the bone is opened or closed at a calculated angle to redistribute load away from the arthritic side. The osteotomy is held with a plate and screws while the bone heals.

Recovery

Crutches with partial weight-bearing for several weeks while the osteotomy heals. Return to most activities by 4–6 months. HTO is a delaying procedure — it preserves the patient's own joint and defers joint replacement, often by many years.

Next step

A knee consultation
with Mr Gormack.

Request a referral from your GP, physiotherapist, or other health professional — or contact the clinic directly to begin.

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