Total Knee Arthroplasty Conversion after Open-wedge High Tibial Osteotomy

Background: Open-wedge High Tibial Osteotomy (HTO) is an effective treatment for Osteoarthritis (OA) of the knee; however, postoperative changes due to HTO can make subsequent Total Knee Arthroplasty (TKA) technically difficult and can affect long-term survival. Case Report: Medio-lateral stability along with balanced flexion and extension gaps provides a good functional outcome. A 71-year-old man underwent TKA conversion after open-wedge HTO 12 years earlier; the conversion was performed due to arthritic deterioration in the knee. Medial instability was noted because of poor ligament balancing. The residual medial instability was managed with a knee brace due to the unavailability of the constrained prosthesis. Management of persistent mediolateral instability persisting after soft tissue release and balancing ideally requires varus-valgus constraint. Conclusion: TKA conversion after open-wedge HTO requires a special technique and careful preparation before surgery.

Open-wedge high tibial osteotomy in patients with discoid lateral meniscus

Background: There are concerns about the progression of the lateral osteoarthritis (OA) should be taken into account when high tibial osteotomy (HTO) is performed in patients with discoid lateral meniscus (LM). This study evaluated the clinical results of HTO in patients with discoid LM and elucidated factors affecting the results. Methods: This study evaluated 32 female patients with varus deformity and medial OA. Patients with discoid LM (8 patients) or without discoid LM (24 patients) underwent open-wedge HTO. The mean age was 53.5 years and the mean follow-up period was 35 months. Clinical results, including the Hospital for Special Surgery (HSS) score, Knee Society knee score (KS) and function score (FS), were evaluated. The progression of OA in the lateral compartment was also evaluated. Finally, we evaluated the factors affecting the clinical results and OA progression in the lateral compartment. Results: Between two groups, all clinical scores were not different (p = 0.964, 0.963, and 0.559, respectively). Three of eight patients (37.5%) in the discoid group developed OA in the lateral compartment, whereas 2 of 24 patients (8.3%) in the control group developed such; however, this was not significantly different (p = 0.085). In discoid group, patients with undercorrection has higher KS relative to patients with acceptable correction (p = 0.044). Other clinical results and OA change in the lateral compartment were not affected by evaluated factors. Conclusions: Patients who underwent open-wedge HTO showed the satisfactory clinical results and lateral OA progression regardless of the presence or absence discoid LM. However, when discoid LM was present, patients with undercorrection showed higher KS in comparison with patients with acceptable correction.

Return to sport and work after medial open wedge high tibial osteotomy : a case series

Data on return to work and sport following open wedge high tibial osteotomy (HTO) have been underreported. Furthermore, there is no clear consensus in literature about the postoperative alignment goals following HTO. A retrospective case series was performed to evaluate return to sport and work following open wedge HTO. The University of California, Los Angeles scale, the German classification system according to the Reichsausschuß für Arbeitszeitermittlung, the Tegner score and the Knee injury and Osteoarthritis Outcome Score were used to asses the employment status, sport status and clinical outcome at the time of surgery and at final follow-up, minimum 2 years after surgery. The pre- and postoperative hip knee ankle angle (HKA) were documented. The desired postoperative alignment target was 0°-2° valgus mechanical axis. 30 open wedge HTOs were performed of which 27 patients were retrospectively included in the study. 25 out of 26 patients returned to work and 15 out of 17 patients returned to sport following surgery. Outcome scores were significantly higher after surgery. The mean postoperative HKA was 0,9° of valgus mechanical axis. This study shows excellent outcome in sport and work activity and clinical outcome after open wedge HTO. We furthermore suggest that these outcomes can be obtained with a postoperative alignment of 0°-2° of valgus mechanical axis.

Correction to: The effect of the sagittal plane osteotomy inclination on the posterior tibial slope in medial open wedge HTO: experimental study with a square column model

An amendment to this paper has been published and can be accessed via the original article.

Overweight patients benefit from high tibial osteotomy to the same extent as patients with normal weights but show inferior mid-term results

PurposeThe purpose of this prospective study was to analyze the impact of obesity on the clinical and radiological outcomes 6 years after open-wedge high tibial osteotomy (HTO).MethodsA total of 120 prospectively recorded patients with medial compartment osteoarthritis underwent open-wedge HTO between 2008 and 2011. The study cohort was frequently examined over a minimum of a 6-year follow-up. The cohort was divided into three groups according to body mass index (BMI): normal weight patients (BMI < 25 kg/m2), pre-obese patients (BMI 25–30 kg/m2) and obese patients (BMI > 30 kg/m2). Clinical and functional outcomes (Oxford Knee Score, Hospital for Special Surgery Score, Lequesne Score, Tegner Activity Scale), subjective health-related quality of life (SF-36), change in mechanical limb alignment (mTFA) as well as conversion to unicompartmental or total knee arthroplasty (TKA) were evaluated. To compare clinical scoring between the groups, univariate variance analysis was applied. Changes in outcome variables over time were analyzed with dependentttests.ResultsFrom 120 patients, 85 were followed-up over a 6.7-year period on average (6–11.8 years) after HTO. The mean BMI was 28.6 ± 4.6 kg/m2. Each group showed a significant pre- to postoperative increase in all recorded scores(p < 0.05).In absolute terms, both mental and clinical scores of overweight patients did not reach the peak values of the normal weighted population during the period of observation. There was a conversion to TKA in 10.5% after an average of 50.1 ± 25.0 months following surgery. A total of five complications occurred without significant differences (BMI < 25:n = 1, BMI 25–30:n = 2, BMI > 30:n = 2;n.s.).There was a mean pre- to postoperative (six weeks after surgery) correction difference of 6.9° ± 3.2° (mTFA) with higher loss of correction over time in overweight patients.ConclusionIn terms of clinical outcome and health-related quality of life, overweight patients may receive a benefit from open-wedge HTO to the same extent as patients with normal weights and show similar complication rates. However, they have inferior preoperative clinical and functional results and mid-term results after open-wedge HTO compared to patients with normal weights.Level of evidenceLevel III.

The effect of the sagittal plane osteotomy inclination on the posterior tibial slope in medial open wedge HTO: experimental study with a square column model

Background Medial open-wedge high tibial osteotomy (HTO) is an effective and safe treatment method for medial osteoarthritis of the knee. However, unintended changes in the posterior tibial slope (PTS) may occur. Several factors cause PTS alterations after medial open-wedge HTO; however, research on sagittal-plane osteotomy inclination (SPOI) in relation to the PTS is sparse. The purpose of this study was to evaluate whether the SPOI affects changes in the PTS after medial open-wedge HTO. The hypothesis was that an SPOI parallel to the PTS causes no change in the PTS after medial open-wedge HTO. Methods A square column model with a 10° posterior slope was produced using two three-dimensional (3D) programs and a 3D printer. Then, a series of medial open-wedge HTO procedures was performed on the square column model through virtual simulation using the two 3D programs, and an actual simulation was conducted using a 3D printer, a testing machine and a measurement system. The SPOI was divided into four types: ① SPOI 20° (posterior-inclined 10° osteotomy), ② SPOI 10° (osteotomy parallel to posterior slope), ③ SPOI 0° (anterior-inclined 10° osteotomy), and ④ SPOI − 10° (anterior-inclined 20° osteotomy). The correction angle was increased at intervals of 5° from 0° to 30°. The change in posterior slope was measured in the sagittal plane. Results The posterior slope was increased in SPOI 20° (posterior-inclined 10° osteotomy), maintained in SPOI 10° (osteotomy parallel to posterior slope), and decreased in SPOI 0° (anterior-inclined 10° osteotomy) and SPOI − 10° (anterior-inclined 20° osteotomy) based on the correction angle. Conclusions In this study using a square column model, the SPOI affected the change in the PTS, and an SPOI parallel to the PTS caused no change in the PTS after medial open-wedge HTO.

Better outcomes and reduced failures for arthroplasty over osteotomy for advanced compartmental knee osteoarthritis in patients older than 50 years

Background Both compartmental knee arthroplasty (CKA) and open-wedge high tibial osteotomy (HTO) may be used to treat patients older than 50 years of age with advanced compartmental osteoarthritis (OA) secondary to leg axis deformities. A meta-analysis was conducted to clarify the role of open-wedge HTO versus CKA for patients older than 50 years with advanced compartmental knee OA. The present investigation aimed to analyse the clinical outcomes, implant failure and survivorship. Methods This meta-analysis was performed in accordance with the PRISMA guidelines. In September 2020, the main online databases were accessed. All clinical trials comparing the outcomes of open-wedge HTO versus CKA for compartmental knee OA were considered. Data analysis was performed through the Review Manager Software 5.3 (the Nordic Cochrane Collaboration, Copenhagen). Implant survivorship was analysed with a Kaplan-Meier (KM) curve that was performed using the STATA/MP software (StataCorp, College Station, TX). Results Data from 618 (HTO, 307; CKA, 311) patients were collected. Good baseline comparability among patient age, BMI and gender was detected. The Tegner Activity Scale was higher in the CKA group (P = 0.04), as were the Lysholm score (P = 0.001), the International Knee Documentation Committee (P = 0.0001) and the Knee injury and Osteoarthritis Outcome Score (P = 0.05). At a mean follow-up of 5 years, revisions were less in the CKA cohort (OR, 2.27; P = 0.004). The Kaplan-Meier curve evidenced longer implant survivorship in favour of the CKA group (P = 0.01). Conclusion In patients older than 50 years of age with compartmental knee OA secondary to frontal axis leg deformities, CKA performed better than open-wedge HTO.

HKA Angle—A Reliable Planning Parameter for High Tibial Osteotomy: A Theoretical Analysis Using Standing Whole-Leg Radiographs

High tibial osteotomy (HTO) is a recognized treatment for early-stage medial compartment knee osteoarthritis. Preoperative planning with standing whole-leg radiographs (WLRs) is essential for ensuring optimal postoperative alignment. The primary purpose of this study is to investigate the theoretical accuracy of the wedge opening required for two different preoperative planning parameters in open-wedge HTO. The second purpose is to theoretically determine which parameter is superior. Preoperative planning for HTO was performed with standing WLRs for 39 knees with isolated medial osteoarthritis. The Miniaci preoperative planning method was applied to correct the hip-knee-ankle (HKA) angle to 3to 6 degrees of valgus and the weight-bearing line (WBL) percentage within 60 to 70% of the width of the tibial plateau. To ensure that the HKA angle was between 3 and 6 degrees of valgus, the required accuracy window for the Miniaci angle was 3.25 ± 0.03 degrees (range, 3.20–3.30°). To ensure that the WBL percentage was between 60 and 70%, the accuracy window required for the Miniaci angle was 2.35 ± 0.13 degrees (range, 2.10–2.65°). This study suggests that to correct the HKA angle and the WBL percentage within the target range on two-dimensional WLRs, the Miniaci angle must be controlled to an accuracy of ± 1.63 and ± 1.18 degrees, respectively. Theoretically, the HKA angle is highly suitable as a preoperative planning parameter for HTO with a large permissible error and a small variability in the degree of change in the Miniaci angle (ΔMiniaci).

Health-Related Quality of Life – an Underestimated Factor to Evaluate the Treatment Success after Open Wedge HTO Surgery: Prospective 6-Years Follow-Up

Background The subjective health related quality of life in patients with degenerative joint diseases is an important variable to evaluate the treatment outcome. In this study, mid-term results of open wedge HTO were analysed and compared to the subjective quality of life (SF 36) of the general population. Furthermore, the relationships of preoperative assessed subscales of the health-related quality of life (SF 36) and the conversion to knee arthroplasty were analysed. Methods The cohort consisted of 120 patients who were prospectively followed-up after open wedge HTO. At five follow-up points of time, patients were examined and asked about their subjective, health-related quality of life using the SF 36 score. Results 104 patients were included and evaluated until the last follow-up (mean: 81.2 ± 11.3 months after open wedge HTO; follow-up rate: 86.7%). Six years after open wedge HTO, similar values in several psychologic subscales of the SF 36 (BP, GH, V, MH) and the mental health component summary score (MCS) compared to the general population were found. The physical health component summary score (PCS) showed a significant improvement relative to the preoperative values. Nine out of 104 patients (8.7%) received a knee arthroplasty (50.1 ± 25.0 months). Low preoperative values of the subscales “physical functioning” (PF) and “bodily pain” (BP) were identified as risk factors in terms of conversion to a total knee arthroplasty. Conclusions Patients with medial unicompartimental knee osteoarthrosis treated with open wedge HTO showed very good results. The health-related quality of life was nearly as high as in the general population. Patients with preoperative low physical function and high pain values have a higher risk to have a conversion to knee arthroplasty. Surgeons should be aware of these factors if an open wedge HTO is considered.