<prompt> A 68 yr. old man came with pain and swelling of right knee. Ahlback grade 2 osteoarthritic changes were found on investigation. What is the further management?Arthroscopic washoutHigh tibial osteotomyTotal knee replacementConservative  <response>: Ans. is d i.e. Conservative Initial management of most of the patients of knee OA is conservative or non-operative.Campbell operative orthopaedics writes - Osteoarthritis of the knee can cause symptoms ranging from mild to disabling. Initial management of most patients should be nonoperative.Surgical management is needed when the conservative management fails.Surgical management in brief:The choice of surgical procedure depends on the patients age and activity demand, severity of the disease and the number of knee compartments involved.Arthroscopic washout or debridement:It consists of trimming of degenerate meniscal tissue and osteophytesIt may delay the need for a more definitive procedure, especially in younger, active patients with localised degenerative arthritis that causes pain at rest without malalignment or instabilityIt may also be considered in active, older adults with mild to moderate OA Realignment osteotomy:High or proximal tibial osteotomy HTO-High tibial osteotomy is a procedure for the treatment of unicompartmental osteoarthritis of the knee medial or lateral compartment osteoarthritis; usually it is medial; lateral compartment osteoarthritis is uncommon.Medial osteoarthritis is associated with varus deformity of the knee. Varus deformity causes stresses to be concentrated medially, accelerating degenerative changes in the medial part of the joint similarly if the deformity is of valgus position, changes are accelerated in the lateral part.The biomechanical rationale for proximal tibial osteotomy in patients with unicompartmental osteoarthritis of the knee is unloading of the involved joint compartment by correcting the malalignment and redistributing the stresses on the knee joint.Thus medial osteoarthritis is treated by a varus correcting osteotomy ka valgus osteotomy and the uncommon lateral osteoarthritis corrected by valgus correcting osteotomy ka varus osteotomy.According to Ebnezar 3e p547 High tibial osteotomy is done for varus deformity less than 15deg and valgus deformity less than 12deg.Supracondylar or distal femoral osteotomy- - distal femoral osteotomy is done for correction of valgus deformity more than 12 to 15deg Ref: Campbells Orthopaedics 11e chapter 25Total knee arthroplasty:It is done for older patients with advanced OA that causes incapacitating pain and disability or young patients with tricompartmental medial and lateral tibio femoral and patellofemoral disease. But it should be delayed in young patients as long as possible as prostheses may wear out over time and may need further revision surgery.Unicompartmental arthroplasty:In carefully selected patients with either medial or lateral osteoarthritis, it is becoming a viable alternative to TKA and HTO.Knee arthrodesis:Arthrodesis is indicated less commonly than arthroplasty. If the patient is young and involved in heavy occupation, arthrodesis is indicated to give him a stable and strong knee.This procedure provides permanent pain relief and allows the patient to return to durable, active work. However arthrodesis results in a stiff knee which is a severe disability.Ahlbacks grading of osteoarthritisAhlbacks grading is radiological grading of osteoarthritis. Standard textbooks of Orthopaedics Campbell, Turek, Apleys and of Radiology Grainger, Sutton, Greenspans Orthopedic Imaging do not mention anything about it. Treatment of osteoarthritis depends on symptoms and clinical profile of pt and not on radiological grading.Still we are describing the grading below.Grading of osteoarthritisApart from Ahlback grading, other commonly used grading system is by Kellgren and Lawrence. The two grading system are compared as follows:Classification of knee OAAhlbackKellgren and LawrenceGradeDefinitionGradeDefinition Grade 1 doubtfulMinute osteophytes doubtful significant Grade 2 minimalDefinite osteophytes unimpaired air spaceGrade 1Joint space narrowing 3 mmGrade 3 moderateModerate diminution of joint spacesGrade 2Joint space obliterationGrade 4 severeJoint space great impaired with sclerosis of subchondral boneGrade 3Minor bone attrition 0-5 mmGrade 4Same as aboveGrade 4Moderate bone attrition 5-10 mmGrade 4As aboveGrade 5Severe bone attrition 10 mmGrade 4As aboveNote- Grade 1 of Ahlback is equivalent to grade 3 of Kellgren and Lawrence grade 2, 3, 45 of Ahlback is equivalent to grade 4 of Kellgren and Lawrence.It must be noted that the radiological grading may not correlate with clinical symptomology of the patients. The treatment is based on the symptoms of patient and not merely on radiographic appearances 