High tibial osteotomy (HTO) is a common treatment for medial compartment arthritis of the knee in younger, more active patients. The HTO shifts load away from the degenerative medial compartment and into the lateral compartment. This change can be accomplished with either a lateral closing or a medial opening wedge HTO. An HTO also potentially affects leg length. Mathematical models predict that the osteotomy type (opening versus closing) and the magnitude of the correction determine the change in leg length, but no in vivo studies have been published. The purpose of this study is to quantify and compare leg length change following opening and closing wedge HTO. Retrospective cohort study – Level III evidenceIntroduction:
Study Design:
Appropriate positioning of total knee arthroplasty (TKA) components is a key concern of surgeons. Post-operative varus alignment has been associated with poorer clinical outcome scores and increased failure rates. However, obtaining neutral alignment can be challenging in cases with significant pre-operative varus deformity 1) In patients with pre-operative varus deformities, does residual post-operative varus limb alignment lead to increased revision rates or poorer outcome scores compared to correction to neutral alignment? 2) Does placing the tibial component in varus alignment lead to increased revision rates and poorer outcome scores? 3) Does femoral component alignment affect revision rates and outcome scores? 4) Do these findings change in patients with at least 10 degrees of varus alignment pre-operatively?Background:
Questions:
Physeal bar resection for partial growth plate arrest was first described by Langenskjold in 1967. The initial enthusiasm by Peterson (1989) who found that 83% of patients resumed physeal growth was tempered by Birch (1992) who only had 33% success. Poor results were due to failure to resume growth or premature growth arrest. We retrospectively reviewed 21 physeal bar resections performed in 19 children from 1987 to 2003. The average age at surgery was 8.2 years (range 3–12 years). The aetiology of the physeal arrest was : growth plate fracture (8), meningococcal septicaemia (5), osteitis (3; 2 neonatal), dysplasia (3), gunshot (1) and idiopathic (1). The commonest site was the distal femur (12; 5 due to growth plate fracture), followed by the proximal tibia (5; 3 due to meningococcal septicaemia), and the distal tibia (4; 2 due to growth plate fractures). Assessment of the size and location of the bar was with biplanar tomography in 7, MRI in 5 and both in 7. We found equal accuracy with both modalities, but currently prefer MRI. The bar was plotted on an anterior-posterior and lateral map of the growth plate. The average size of the bar was 25% (range 15 to 50%) of the area of the growth plate. Only 3 bars were larger than 30%. Fifteen of the bars were peripheral, 5 linear and 1 central. Results were classified poor if there was no resumption of growth or if premature growth plate arrest occurred, good if there was resumption of growth which continued to maturity or to follow-up, and excellent if the growth exceeded the expected growth. There were 5 (24%) poor results; all failed to resume growth. Three bars exceeded 30% and 2 were due to meningococcal septicaemia. The remaining 16 bars were followed up for a range of 2 to 12 years; 10 to maturity. Four (19%) had an excellent and 12 (57%) had a good result. The authors conclude that physeal bar resection is a worthwhile procedure if the size of the bar is equal to or less than 30% of the area of the growth plate. In growth arrest due to meningococcal septicaemia we only had a 60% success rate.
