Mark Clatworthy Orthopaedic Surgeon Knee Specialist Knee Update Mark Clatworthy Orthopaedic Surgeon Knee Specialist

Overview How to diagnose a meniscal tear and ACL rupture What x rays of the knee should I take? Treatment options for early OA of the knee Knee Arthroplasty update

ACL Injury History taking key to diagnosis Acutely injured knees are painful and swollen making the examination difficult The diagnosis normally lies in the history

ACL Injury Mechanism of injury Normally a side stepping or pivoting manoeuver or an awkward landing Often a non contact injury The posterolateral knee subluxes Patient will feel a pop and the knee gave way

ACL Rupture Patient usually presents with a haemarthrosis Knee may fell unstable with any twisting activity Difficulty weightbearing due to bone bruising The knee subluxes posterolaterally thus this area is usually tender

ACL Rupture Patients often present with a fixed flexion deformity. Initially this is due to bone bruising. A bucket handle tear typically occurs only with multiple giving way episodes

Examination Findings Must examine both knees. Large variation laxity Fixed flexion deformity, reduced flexion

ACL Examination Lachmann - anterior translation tibia

ACL Examination Lachmann – Big leg, small hands

ACL Examination Anterior drawer decreased by posterior horn of the menisci – less positive than Lachmann

ACL Examination Pivot shift test- reproduces the sensation of giving way. Lateral compartment subluxes

Exclude PCL Injury Drop back seen with knee at 90° Compare with other side

PCL Examination Posterior drawer

Meniscal Tear Mechanism of Injury Typically a twisting injury on a loaded knee Often sudden pain Knee swells – variable time frame Mechanical symptoms – catching, locking

Examination Findings Effusion Springy block to extension if bucket handle Point joint line tenderness Pain on meniscal grinding Pain on loading and twisting the knee

Effusion Tense effusion is easily seen, Moderate effusion – patella tap Mild effusion - patella sweep

Meniscal Grind Test

Locked knee Physical block In young patient needs urgent meniscal repair Don’t send to physiotherapist Urgent referral to orthopaedic surgeon We will see the patient that week

What X Ray’s Should I take Weight bearing AP 45º weight bearing PA Lateral Skyline AP Pelvis if unsure about hip

Weight bearing X Rays Weight bearing X rays are critical

45° Weightbearing PA

Skyline patella

Treatment Options for Early OA Knee Non surgical treatment Arthroscopy High Tibial Osteotomy

Non Surgical Treatment Analgesics & Anti – inflammatories Glucosamine & Chondrotin Sulphate – variable response Intra-articular steroid – short term benefit – Cochrane 1 week Accelerates cartilage degeneration Viscosupplementation – controversial Knee Sleeve Exercise – low impact – exercycle If the knee is painful and swollen. Stop it Physiotherapy – maximize muscle strengthening Orthotics

Early OA and Arthroscopy Arthroscopic debridement and lavage has unpredictable results thus is not indicated If a symptomatic meniscal tear with pain and mechanical symptoms worthwhile however must caution the patient that the knee will not be normal due to OA

Proposed ACC Guidelines Clear history of injury Signs and symptoms of a meniscal tear Less than 50% joint loss on weight bearing X rays Full thickness chondral lesions on MRI excluded

High Tibial Osteotomy Indicated for younger patient with varus knee with medial compartment OA

High Tibial Osteotomy Two hour operation, 2-3 days in hospital Six weeks on crutches with a brace Three – six month recovery Knee better - not normal VAS pain 7.1  2.6 at 5 years Sydney study – 84% survival at 15 years 186 cases last 12 years – 4 converted to TKA

Total Knee Arthroplasty Perception in the community Only lasts 10 years Very painful operation and the knee will continue to be painful Doesn’t work that well. Knee will be stiff

TKA Survival National registries New Zealand 96% at 10 years Australia 92% at 8 years Swedish 95% at 10 years Norwegian 88% at 12 years Expert Designer Series 92% at 16 years 93% at 15 years 87% at 18 years > 60 years > 90% implant will last life time

Survival – Age at TKA

Activity level & Pain Younger patient more active thus higher failure rate TKA is designed for every day activity Walking, golf, tramping, groomed skiing, doubles tennis TKA is not designed for impact loading activities – running, jumping, dancing, singles tennis The knee will be painful, swollen, warm and stiff for up to 6 months. Must take pain medication TKJR will get rid of most but not necessarily all of the pain. VAS pain – 6.8  1.0 – 60% no pain

Improving Outcome Computer Guided TKA Enables the surgeon to: Ensure accurate alignment – enhancing implant survival Balance the ligaments to ensure good kinematics Customize the TKA to patients anatomy & ligamentous laxity Mobile Bearing TKA RCT showed better knee function Less wear in lab

NZ Joint Registry Oxford 6 months NZOA Conventional NZOA NAV Clatworthy NAV Score 37 38.3 40.3 Poor 12.4% 10.0% 0% Fair 16.3% 6.8% Good 35.4% 37.5% 30.3% Excellent 35.9% 40.1% 62.8%

Oxford Score Significance Statistically significant relationship between 6 month Oxford score and revision rate Every 1 unit decrease in Oxford score increases the revision rate at 2 years by 10.4% A patient with a score <20 has a 30 times the revision rate of a patient with a score > 36 ROC (Receiver operating characteristic) analysis demonstrates < 31 has an 8 times greater risk of revision than a score > 31

Oxford Score & Revision Rate Poor Fair Good Excellent

NZ Joint Registry Oxford 6 months NZOA Conventional NZOA NAV Clatworthy NAV Score 37 38.3 40.3 Poor 12.4% 10.0% 0% Fair 16.3% 6.8% Good 35.4% 37.5% 30.3% Excellent 35.9% 40.1% 62.8%

Range of Motion - Stiffness Pre-Operative Post-Operative Overall 110° 118° <90° +45° 90° - 125° +6° >125° -11°

Complications Infection - Hot, painful, swollen, stiff knee - Wound may be oozing - Patient will often report a sudden increase in pain and decrease in movement - If in doubt refer back to operative surgeon - Don’t start antibiotics unless you are sure it is a superficial stitch abscess DVT - Hot, tense painful calf - If in doubt refer for ultrasound

Websites www.aucklandboneandjoint.co.nz Tonight’s talks available on website www.markclatworthy.co.nz All my information sheets, pre and post op instructions, surgical videos and comprehensive information on knee conditions and treatment