High Tibial Valgus Osteotomy: Closing, Opening or Combined? Patellar Height as a Determining Factor

Abstract

BackgroundAccording to the literature, closing and opening wedge high tibial valgus osteotomies can raise or lower the patella, and diffèrent methods of patella height measurement show similarly conflicting results. Clarification of this was thought to be important because there is much literature describing morbidity secondary to patella alta or patella infera (baja). Effects on tibial slope and patellar tendon length are not well delineated and the influence of sex and age is unknown.Questions/purposeA group of patients who underwent high tibial valgus osteotomy was investigated to determine how surgical technique influenced postoperative (1) patellar height and (2) tibial slope and patellar tendon length, and (3) whether age or gender independently influenced postoperative patellar height. To eliminate the often conflicting results seen when several ratio methods are used, patellar height was measured by one method, before and after surgery, shown previously to be reliable.MethodsPatellar height was measured on radiographs using the plateau-patella angle in a retrospective case series consisting of three cohorts: 18 patients with closing wedge osteotomies, 26 with opening wedge osteotomies, and 32 with combined osteotomies. The indication for surgery in all three cohorts was medial osteoarthritis with secondary varus. Before surgery there were no significant differences in patellar height, femorotibial angle, age, or gender among the three groups, and no patients were lost to followup during the 8-week study period after surgery. Seven of the 76 patients (9.2%), all in the opening wedge cohort, had concomitant ACL reconstruction at the time of the tibial osteotomy. No other surgery, except arthroscopy, was performed at the time of osteotomy. Patellar tendon length was assessed by the Insall-Salvati index and tibial slope by the angle between the posterior tibial cortex and the medial tibial joint line. Postoperative measurements were made between 6 and 8 weeks. The influence of sex and age was calculated using patellar height measurements made before any surgery.ResultsAll closing wedge osteotomies produced patellar ascent by an average of 13% (p < 0.001), all opening wedges produced descent by an average of 21% (p < 0.001), and the combined osteotomy mean showed minimal change (p = 0.0034). The absolute consistency of the changes and their direction allow suggested guidelines for selection of osteotomy type. There were only slight changes in tibial slope. A significant change in patellar tendon length was seen in seven knees of the opening wedge cohort that had concomitant ACL reconstruction. All had a mean reduction of the Insall-Salvati index of 0.05 (approximately 5%), p = 0.0002. New findings showed higher patellae in female and older patients, unrelated to the surgery.ConclusionsIf it is accepted that patella baja and patella alta should be avoided, then closing wedge osteotomies should be performed only when the patella is low riding, and opening wedge osteotomies should be done only for patients with p...

Plateau-Patella Angle: An Option for Assessing Patellar Height on Proximal Tibia Osteotomy

“…The reduction of patellar tendon length resulting from fibrosis, despite having already been demonstrated in previous studies, 16 was not found in our evaluation. Since we used x-rays performed only 3 months after surgery, it is still possible that some variation may have occurred regarding the shortening of the tendon.…”

Comparison between Closing-Wedge and Opening-Wedge High Tibial Osteotomy in Patients with Medial Knee Osteoarthritis: A Systematic Review and Meta-analysis

“…The maximum follow-up period was > 10 years, 13 and the minimum period was 2 weeks. 14 Four studies [15][16][17][18] used the Ahlbäck grade to evaluate the severity of the knee OA. Other studies used different standards such as IKS knee score, 18 and K/L score.…”

Patellar Height Is Not Altered When the Knee Axis Correction Is Less than 15 Degrees and Has Good Short-Term Clinical Outcome

“…The literature on OWHTO describes three main limitations of the procedure: (1) the risk of increasing the posterior tibial slope (PTS), (2) the risk of a lowering of the patella, and (3) the possible difficulty converting to total knee arthroplasty. [8][9][10][11] However, the change in patellar height after OWHTO is still controversial. Some studies addressed that OWHTO results in a decrease in the patellar height which may lead to patella baja.…”