Changes of Sagittal and Axial Alignments of Patella after Open- and Closed-Wedge High-Tibial Osteotomy: A Systematic Review and Meta-Analysis

Abstract

The present systematic review and meta-analysis were aimed to verify the effect of open-wedge (OW) and closed-wedge (CW) high-tibial osteotomy (HTO) on sagittal and axial alignments of the patella. A vigorous search was performed for studies that compared the changes of sagittal and axial alignments of patella after OW and CW HTO. After evaluating publication bias and heterogeneity, we aggregated variables by using the random-effects model. The weighted mean differences in sagittal and axial alignment of patella were estimated with 95% confidence intervals. Also, we analyzed the changes in sagittal alignment of various OW HTO techniques, such as uniplanar, biplanar, and retrotubercle osteotomy. Overall, 20 studies that included 831 OW HTOs and 206 CW HTOs were included in this study. Patellar height decreased after OW HTO based on the Blackburne-Peel index (BPI, mean: -0.10), and Caton-Deschamps index (CDI, mean: -0.08). However, the patellar height after CW HTO showed no change after surgery (BPI [mean: -0.02], and CDI [mean: 0.02]). Among OW HTO techniques, the retrotubercle osteotomy showed the least change in patellar height after surgery. The lateral patellar tilt decreased by 1.74 degrees, and lateral patellar shift showed no change after OW HTO. However, there was a lack of evidence to conclude the change of axial alignment of patella after CW HTO. Our results supported that the sagittal alignment of patella lowered after OW HTO. However, CW HTO maintained the constant sagittal position of the patella. Among OW HTO techniques, the retrotubercle osteotomy had the least effect on the sagittal alignment of the patella. Regarding the axial alignment of the patella, OW HTO resulted in a little change of lateral patellar tilt; however, there was little evidence to confirm the change of the axial alignment of patella after CW HTO.

Medial UKA tends to increase patellar height, whereas open-wedge HTO tends to decrease patellar height

“…The change in patellar height after HTO could be the result of various factors, such as patellar ligament scarring due to immobilization, change in sagittal tibial slope, as well as elevation or depression of the tibial plateau. In the metaanalysis by Lee et al [17], the reduction in patellar height after open-wedge HTO according to the Blackburne-Peel (mean, -0.10) and Caton-Deschamps (mean: -0.08) indices were identical to those measured in the present study (-0.10 and -0.08, respectively). A decrease in patellar height could result in patella baja, which can compromise patellofemoral biomechanics, and could require subsequent total knee arthroplasty (TKA) [17].…”

“…In the metaanalysis by Lee et al [17], the reduction in patellar height after open-wedge HTO according to the Blackburne-Peel (mean, -0.10) and Caton-Deschamps (mean: -0.08) indices were identical to those measured in the present study (-0.10 and -0.08, respectively). A decrease in patellar height could result in patella baja, which can compromise patellofemoral biomechanics, and could require subsequent total knee arthroplasty (TKA) [17]. Furthermore, revision to TKA can be challenging in knees with patella baja, though patellar eversion or patellar tendon avulsion remains straightforward if reductions in patellar height are small [3].…”

“…UKA [14] is a procedure that resurfaces only the affected compartment, whereas HTO [28] is a procedure that preserves the affected part of the joint, but transfers the principal load of body weight from the affected compartment to the unaffected compartment. Both open-and closed-wedge HTO are common procedures with equivalent outcomes [17], although open-wedge HTO has been performed more frequently in patients with medial compartment osteoarthritis [3]. A recent meta-analysis [7] that compared UKA to open-and closed-wedge HTO revealed lower revision rates and fewer complications after UKA, superior range of motion after HTO, but no difference in clinical scores.…”

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

“…Some studies addressed that OWHTO results in a decrease in the patellar height which may lead to patella baja. [12][13][14][15][16][17][18] Some studies highlighted that the change in patellar height also affects patellar tracking, which also results in alterations in patellofemoral congruency, and contact stress would thus increase cartilage pressure and lead to patellofemoral degeneration or patellofemoral OA. 17,[19][20][21] In contrast, some studies reported that the changes in patellofemoral alignment do not have a clinical impact after OWHTO.…”

The effect of distal tibial tuberosity high tibial osteotomy on postoperative patellar height and patellofemoral joint degeneration

“…In addition, the patellofemoral joint on the sagittal plane is also influenced by the operation [2]. Several studies have shown that OWHTO causes patellar infera, increases patellofemoral joint pressure pain, increases the risk of patellofemoral OA progression, and makes it more difficult for total knee arthroplasty to be performed in the future [3][4][5][6][7][8]. Kim et al [8] reported the prevalence of the progression of patellofemoral OA to be 41.2% in the femoral trochlea and 21.9% in the patella articular surface after more than 2 years in 114 patients who underwent OWHTO.…”