Isolated Antero medial Osteoarthritis on the rise among Indian Patients Undergoing TKA

Written By : Dr Supreeth D R |Medically Reviewed By : Dr. Kamal Kant Kohli Published On 2022-11-02T19:30:54+05:30 | Updated On 2 Nov 2022 7:30 PM IST

Isolated antero-medial osteoarthritis (AMOA) of the knee is a distinct pattern of arthritis. Medial arthritis of the knee in select patients can be managed with uni-compartmental arthroplasty (UKA), with studies showing shorter hospital stay, faster rehabilitation and reduced medical complications in the post-operative period compared to TKA. However, the prevalence of AMOA in Indian patients with osteoarthritis of the knee is unknown.

Adarsh Annapareddy et al conducted a study to evaluate the prevalence of AMOA in patients undergoing primary TKA for OA. A prospective evaluation was done in 2518 knees in 1936 patients who were selected for primary TKA. Pre-operative radiographs were screened based on the Oxford UKA Radiological decision aid and diagnosis of AMOA was established. All 2518 knees underwent primary total knee arthroplasty.

AMOA Pattern of arthritis was confirmed intraoperatively, with the following criteria, which were documented photographically.

1. Intact ACL

2. Functional ACL with linear striations or fibrillations

3. Normal lateral compartment cartilage

4. Antero-medial OA on the resected tibial biscuit

5. Absence of lateral patellar facet arthritis/ cartilage loss over the trochlea.

Cases with AMOA arthritic wear pattern were considered amenable for UKA if radiographs showed intact lateral joint space, intra-operatively those with intact and functional ACL, acceptable patellofemoral wear (Outerbridge I–II)

.Key findings of the study were:

• 2518 knees (1936 patients with 1354 unilateral TKA and 582 bilateral TKA).

• There was a female preponderance with 1715 (68.1%) knees in females and 803 (31.89%) knees in male patients.

• The average age was 62 years (range 48–72 years).

• The average BMI of all the patients was 30.5 (28 to 35).

• Prevalence of AMOA in 46.94% knees, who were amenable for UKA.

• Obese patients were more likely to have a damaged or non-functional ACL and more likely to have a high degree of wear, not amenable for UKA (p<0.05).

• Non-functional ACL was associated with higher prevalence of posterior extension of arthritic wear.

The authors concluded that – "This study demonstrated a high prevalence (46.94%) of anteromedial osteoarthritis (AMOA) in Indian patients undergoing primary total knee arthroplasty. These patients were all amenable to medial unicompartmental arthroplasty based on Oxford selection criteria. Patient selection is important for improving outcomes after TKA or UKA. Future studies are warranted to compare outcomes of both UKA and TKA in patients with isolated AMOA of the knee."

MBBS, Dip. Ortho, DNB ortho, MNAMS

Dr Supreeth D R (MBBS, Dip. Ortho, DNB ortho, MNAMS) is a practicing orthopedician with interest in medical research and publishing articles. He completed MBBS from mysore medical college, dip ortho from Trivandrum medical college and sec. DNB from Manipal Hospital, Bengaluru. He has expirence of 7years in the field of orthopedics. He has presented scientific papers & posters in various state, national and international conferences. His interest in writing articles lead the way to join medical dialogues. He can be contacted at editorial@medicaldialogues.in.

Dr. Kamal Kant Kohli

Dr Kamal Kant Kohli-MBBS, DTCD- a chest specialist with more than 30 years of practice and a flair for writing clinical articles, Dr Kamal Kant Kohli joined Medical Dialogues as a Chief Editor of Medical News. Besides writing articles, as an editor, he proofreads and verifies all the medical content published on Medical Dialogues including those coming from journals, studies,medical conferences,guidelines etc. Email: drkohli@medicaldialogues.in. Contact no. 011-43720751