1. Mark Clatworthy Orthopaedic Surgeon Knee Specialist
Knee Update
Mark Clatworthy Orthopaedic Surgeon
Knee Specialist

2. 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

3. 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

4. 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

5. 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

6. 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

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

8. ACL Examination
Lachmann - anterior translation tibia

9. ACL Examination
Lachmann – Big leg, small hands

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

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

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

13. PCL Examination
Posterior drawer

14. 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

15. 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

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

17. Meniscal Grind Test

18. 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

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

20. Weight bearing X Rays
Weight bearing X rays are critical

21. 45° Weightbearing PA

22. Skyline patella

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

24. 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

25. 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

26. 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

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

28. 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

29. 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

30. 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

31. Survival – Age at TKA

32. 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

33. 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

34. 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%

35. 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

36. Oxford Score & Revision Rate
Poor Fair Good Excellent

37. 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%

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

39. 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

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