Assessment the changes in patellofemoral compartment in medial opening wedge osteotomy of tibia in patient with genuvarum deformity

Medial open wedge high tibial osteotomy is effective for the treatment of medial compartment osteoarthritis of the knee. Beside the advantages of MOWHTO several studies reported that MOWHTO had adversely affect like patella baja and increased patellofemoral contact pressure in the patellofemoral joint. There are various factors that could affect the progression of the patellofemoral osteoarthritis. Pressure distribution due to underlying varus deformities has a major influence on the onset and development of osteoarthritis in the knee joint. Therefore, several surgical therapies aiming to relief pressure in the medial compartment of the knee joint are applicable.

The present study was a retrospective case series study on all patients with symptomatic osteoarthritis of the knee medial compartment with a deformed varus field requiring correction of deformities who referred to Imam Khomeini Hospital in Ahwaz in 2016-2018. At the last follow-up session, assessment of the patella changes based on Insall and Blackburn indices, pre and postoperative radiological measurements include the Mechanical Axis Deviation (MAD).

A total of 49 knees recruited. 52.6% of patients were male. The mean age of patients was 26.55±5.876 years and the mean body mass index of patients was 25.05±2.903 kg/m2. None of the knees showed signs of revision surgery. Intra-articular fracture did not occur in any of the patients after surgery. The mean score of VAS increased significantly after surgery (P <0.05). Patellar changes before and after surgery were not statistically significant based on Insall and Blackburn indices (P >0.05).The mean pre- and postoperative measurements was (−8.90° ± 3.07° to 0.2° ± 2.780°) (−varus; +valgus) for the MAD

Based on the results the proper correction in MAD was obtained and no significant change in patellofemoral joint biomechanics was seen.