Higher conversion rate to knee arthroplasty in female patients following medial open-wedge high tibial osteotomy.

PURPOSE: Most studies about medial open-wedge high tibial osteotomy (HTO) reported outcomes without focusing on gender differences. Therefore, the study compared the long-term survival rate and postoperative subjective knee function after HTO in female versus male patients with symptomatic medial compartment knee osteoarthritis. METHODS: The data of three cohorts with long-term outcomes were analysed (n = 245; 32% females; age: 49 ± 7 years; Kellgren Lawrence Grade I 6.1%, II 32.7%, III 42.4%; IV 18.8%). The minimum follow-up was at least 6 years or an earlier conversion to total knee arthroplasty (TKA). The gender-specific survival rate after HTO was calculated after 5 and 10 years and compared using Kaplan-Meier analysis and the logrank test. Baseline characteristics and subjective knee function (International Knee Documentation Committee [IKDC]/Lysholm) were analysed between both genders. RESULTS: Forty of 78 (51.3%) women and 41 of 167 men (24.5%) underwent TKA. HTO survival in females was significantly lower (p = 0.0010). The 5- and 10-year survival rates were 85.9% and 62.6% for females and 93.4% and 77.7% for males. In females and males, from preoperative to the last follow-up, the IKDC (43 ± 15 to 58 ± 17; 47 ± 14 to 67 ± 18) and the Lysholm (42 ± 18 to 72 ± 18; 55 ± 22 to 77 ± 23) improved significantly (all p < 0.0001). Females had significantly lower preoperative and postoperative IKDC (p = 0.0438; p = 0.0035) and Lysholm scores (p = 0.0002; p = 0.0323). But the absolute improvements of the IKDC and Lysholm were not significantly different between genders. CONCLUSIONS: Females had higher conversion rates to TKA and lower knee function at the last follow-up. However, preoperative knee function was lower in females and the absolute improvement following HTO was similar for both genders. In general, females benefit from HTO to treat medial knee arthritis, and TKA could be postponed for half of female patients for more than 10 years. However, surgeons must be aware of the described inferior outcomes in females for realistic patient expectation management. LEVEL OF EVIDENCE: Level II.

Obesity does not impact complications and conversion to total knee arthroplasty after high tibial osteotomy: A systematic review.

PURPOSE: The purpose of this systematic review is to consolidate outcomes of obese patients undergoing high tibial osteotomy and to investigate the effect of obesity on postoperative outcomes, including symptomatic relief and time to conversion to arthroplasty. METHODS: Medline, Embase and Cochrane Library were searched from database inception up to April 2023 according to PRISMA guidelines by two reviewers. Search terms including 'obesity', 'BMI', 'osteotomy' and 'high tibial osteotomy (HTO)' were included to identify all relevant articles. Only studies that explicitly reported outcomes for obese patients were included. Disagreements in study inclusion or quality assessment were resolved by a senior third reviewer. Metrics compared include time to arthroplasty, preoperative and postoperative mechanical tibiofemoral angle (mTFA), patient-reported satisfaction scores and postoperative complications. RESULTS: Nine studies comparing 973 patients were included. The mean age was 52.7 ± 4.2 years old and 38.4% were male. Six studies performed the medial opening-wedge HTO, and three utilized the medial wedge closing technique. Most studies indicated significant improvement following surgical intervention with satisfactory outcomes in obese and nonobese patients. In addition, differences in complication rates were minimal between obese and nonobese patients (n.s.), while functional scores did not vary significantly. Conversion to total knee arthroplasty was not found to increase in obese patients (n.s.). CONCLUSION: Obesity does not appear to carry a greater complication risk or worse outcomes following high tibial osteotomies, and surgeons should consider HTO a viable option for young obese patients with symptomatic unicompartmental chondral wear with coronal limb malalignment. LEVEL OF EVIDENCE: Level IV.

Medium to long term of self-report outcomes of high tibial osteotomy in advanced age patients.

PURPOSE: This study aimed to investigate the mid- to long-term benefits of high tibial osteotomy in advanced age patients. METHODS: This retrospective study was conducted in our hospital from January 2017 to January 2021 with data prospectively collected, 47 patients with knee osteoarthritis who over 65 years old were included, and a 1:1 propensity score (PS) of patients < 65 years were matched according to gender, body mass index, and side. Patient demographics, intraooperative and postoperative variables, and patient self-reported outcomes were compared. A generalized linear model was used to screen possible risk factors. RESULTS: A total of 94 consecutive patients were included; the average age of advanced age group was 69.47 + 4.26 years and 57.87 + 5.51 years in the younger group. There were no statistically difference in K-L grade, smoke, drink, comorbidity, ASA, blood loss, operative duration, length of stay, surgical site infection, hinge fracture, DVT, and preooperative and postoperative aFTA; significantly statistical difference of the eFI was found between two groups (P < 0.05). Two groups had comparable VAS and MOMAC scores at one year postoperatively (P > 0.05), while the younger group had lower VAS and WOMAC scores than the advanced age group at the end of follow-up (P < 0.05). Generalized linear model showed both age and eFI were associated with WOMAC scores; there was a statistically significant difference in the effect of eFI on WOMAC scores at different ages (P > 0.05). CONCLUSIONS: Compared with younger patients, advanced age patients have similar short-term benefits, but less long-term benefits. We recommend that patients proposed for HTO be discriminated by eFI, and patients with higher scores should be cautiously selected.

Osseous factors influencing distal tibial rotation in biplane medial opening wedge high tibial osteotomy.

PURPOSE: There is a lack of studies investigating the distal tibial rotation (DTR) during medial opening wedge high tibial osteotomy (MOWHTO). This study was designed to evaluate osseous factors influencing DTR in patients who underwent biplane MOWHTO. METHODS: A total of 106 knee joints in 69 patients who underwent surgery for varus malalignment of knee were reviewed. Based on several software, standard and actual hinge positions were defined in pre-operative and post-operative CT data. Pearson's correlation and Spearman's correlation analysis were performed with DTR change as the dependent variable. Independent variables included angles between standard and actual hinge in the sagittal (ASAHS) and axial (ASAHA) planes, pre-operative and post-operative medial proximal tibial angle, opening width (OW), tuberosity osteotomy angle, flange angle (FA), gap ratio, and hinge fracture. RESULTS: The distal tibia rotated approximately 0.35° internally. Pearson's and Spearman's correlation analysis showed that DTR change was associated with ASAHS, OW, and FA. Larger OW and FA resulted in higher external rotation angles. CONCLUSIONS: DTR change was significantly associated with ASAHS, followed by OW and FA rather than ASAHA if only considering osseous factors in biplane MOWHTO. The distal tibia tended to rotate externally when the actual hinge was inclined posteriorly to the standard hinge in the sagittal planes, but rotate externally or internally when the actual hinge was inclined anteriorly.

Intrafocal injection of tranexamic acid decreases early return to hospital after high tibial osteotomy.

INTRODUCTION: High tibial osteotomy (HTO) is a surgery performed to treat the symptoms and prevent the progression of medial osteoarthritis. Post-operative bleeding has led to early returns to hospital following surgery. Intrafocal injection of tranexamic acid (TXA) could reduce this bleeding complication. The objective of the study was to evaluate the effect of TXA during HTO on the incidence of post-operative complications and early returns to hospital. MATERIALS AND METHODS: This retrospective study included 251 cases of HTO performed between May 2012 and October 2021, with the use of TXA introduced in May 2017. The experimental (n = 102) and control (n = 149) groups were compared as to the rate of post-operative early returns. The influence of confounding factors was evaluated, including age, sex, body mass index (BMI), tobacco use, grade of medial femorotibial osteoarthritis (MFTO), magnitude of angular correction (MAC), and surgery duration. RESULTS: No statistically significant difference was found between the groups with regards to all variables except age. The experimental group was significantly older (54.4 years; σ = 7.5) than the control group (50.4 years; σ = 7.9; p < 0.001). We observed a decrease in emergency department (ED) visits in the experimental group (15.7%) compared to the control (30.2%; p = 0.008) and a decrease in early returns in the experimental group (28.4%) compared to the control (40.5%; p = 0.049). No statistically significant difference in demographic data, MFTO, or MAC was found among patients with and without an early return, in both the experimental and control groups. CONCLUSION: The intrafocal injection of TXA during HTO decreases early returns to hospital.

High survivorship rate and good clinical outcomes after high tibial osteotomy in patients with radiological advanced medial knee osteoarthritis: a systematic review.

INTRODUCTION: The role of valgus producing high tibial osteotomy (HTO) for the treatment of advanced knee osteoarthritis (OA) is still controversial. The aim of the current systematic review was to assess survivorship and patient-reported outcomes (PROMs) of high tibial osteotomy in patients with radiological advanced medial knee OA. METHODS: A systematic search of PubMed, Cochrane and EMBASE database was performed in July 2023 in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. Inclusion and exclusion criteria were applied to identify studies investigating the survivorship rate and PROMs of valgus-producing high tibial osteotomy in patients with advanced knee OA at x-ray assessment in the medial compartment at minimum-two-years follow up. Advanced radiological OA was defined as Kellgren Lawrence (K-L) ≥ 3 or Ahlbäch ≥ 2. Survivorship was defined as percentage of patients free of total knee arthroplasty (TKA) at follow-up. Clinical interpretation of provided PROMs were performed according to minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) target values reported in literature. Survivorship data and PROMs scores were extracted, and studies were stratified based on selected study features. The quality of included studies was assessed with modified Coleman score. RESULTS: A total of 18 studies, totalling 1296 knees with a mean age between 46.9 and 67 years old, were included. Average survivorship was of 74.6% (range 60 - 98.1%) at 10-years follow up. The subjective scoring systems showed good results according to MCID and PASS, and postoperative improvements were partially maintained until final follow-up. CONCLUSION: HTO is worth considering as treatment choice even in patients affected by radiological advanced medial knee osteoarthritis. Long term survivorship and good patient reported clinical outcomes could be expected in this population. LEVEL OF EVIDENCE: IV; systematic review of level III-IV studies.

Comparison of joint awareness after total knee arthroplasty, medial unicompartmental knee arthroplasty, and high tibial osteotomy: a retrospective study.

INTRODUCTION: This study aimed to compare the Forgotten Joint Score-12(FJS) outcomes and the minimum clinically important difference (MCID) of the FJS after high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA), and total knee arthroplasty (TKA) with short-term follow-up (at least 2 years). Another objective of the study is to investigate the factors influencing FJS. It is hypothesized that there are differences in FJS outcomes among the three procedures. METHODS: Patients who underwent HTO, UKA, and TKA from January 2016 to December 2020 and were followed up for a minimum of 2 years were included in the study. The FJS were analyses from a cohort of people who submitted data to two years. The preoperative and postoperative clinical outcomes were compared and evaluated the patient-related factor. The FJS scores were predicted using multiple linear regression analysis. Additionally, Patient's Joint Perception (PJP) questions were used as anchors to determine the achievement of the forgotten joint, and FJS MCID were calculated using the receiver operating characteristic curve (ROC). RESULTS: Three hundred eighty-nine patients were included in the final study, and there were 111 patients in HTO groups,128patients in UKA groups, and 150 patients in TKA groups. The mean follow-up was 47.0 months. There was a significant difference in the total FJS, between the HTO, UKA, and TKA groups (FJS:59.38 ± 7.25, 66.69 ± 7.44 and 56.90 ± 6.85, p < 0.001. We found the MCID of the FJS of HTO, UKA, and TKA were 63.54, 69.79, and 61.45, respectively. In multiple linear regression, younger age, and higher FS were significant predictors of better FJS. CONCLUSION: Medial UKA demonstrated lower patient awareness in comparison to HTO and TKA, as assessed by the FJS. Younger age and higher FS were identified as significant predictors of improved FJS, providing valuable guidance for surgical decision-making.

Artificial intelligence-based analyses of varus leg alignment and after high tibial osteotomy show high accuracy and reproducibility.

PURPOSE: The aim of this study was to investigate the performance of an artificial intelligence (AI)-based software for fully automated analysis of leg alignment pre- and postoperatively after high tibial osteotomy (HTO) on long-leg radiographs (LLRs). METHODS: Long-leg radiographs of 95 patients with varus malalignment that underwent medial open-wedge HTO were analyzed pre- and postoperatively. Three investigators and an AI software using deep learning algorithms (LAMA™, ImageBiopsy Lab, Vienna, Austria) evaluated the hip-knee-ankle angle (HKA), mechanical axis deviation (MAD), joint line convergence angle (JLCA), medial proximal tibial angle (MPTA), and mechanical lateral distal femoral angle (mLDFA). All measurements were performed twice and the performance of the AI software was compared with individual human readers using a Bayesian mixed model. In addition, the inter-observer intraclass correlation coefficient (ICC) for inter-observer reliability was evaluated by comparing measurements from manual readers. The intra-reader variability for manual measurements and the AI-based software was evaluated using the intra-observer ICC. RESULTS: Initial varus malalignment was corrected to slight valgus alignment after HTO. Measured by the AI algorithm and manually HKA (5.36° ± 3.03° and 5.47° ± 2.90° to - 0.70 ± 2.34 and - 0.54 ± 2.31), MAD (19.38 mm ± 11.39 mm and 20.17 mm ± 10.99 mm to - 2.68 ± 8.75 and - 2.10 ± 8.61) and MPTA (86.29° ± 2.42° and 86.08° ± 2.34° to 91.6 ± 3.0 and 91.81 ± 2.54) changed significantly from pre- to postoperative, while JLCA and mLDFA were not altered. The fully automated AI-based analyses showed no significant differences for all measurements compared with manual reads neither in native preoperative radiographs nor postoperatively after HTO. Mean absolute differences between the AI-based software and mean manual observer measurements were 0.5° or less for all measurements. Inter-observer ICCs for manual measurements were good to excellent for all measurements, except for JLCA, which showed moderate inter-observer ICCs. Intra-observer ICCs for manual measurements were excellent for all measurements, except for JLCA and for MPTA postoperatively. For the AI-aided analyses, repeated measurements showed entirely consistent results for all measurements with an intra-observer ICC of 1.0. CONCLUSIONS: The AI-based software can provide fully automated analyses of native long-leg radiographs in patients with varus malalignment and after HTO with great accuracy and reproducibility and could support clinical workflows. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Preoperative joint line convergence angle correction is a key factor in optimising accuracy in varus knee correction osteotomy.

PURPOSE: This study aimed to identify and prevent preoperative factors that can be influenced in preoperative planning to reduce postoperative malcorrections. METHODS: The method used in this study was a retrospective two-centre analysis of 78 pre and postoperative fully weight-bearing radiographs of patients who underwent valgus osteotomy correction due to symptomatic medial compartment osteoarthritis. A computer software (TraumaCad®) was used to aim for an intersection point of the mechanical tibiofemoral axis (mTFA) with the tibia plateau at 55-60% (medial = 0%, lateral = 100%). Postoperative divergence ± 5% of this point was defined as over- and undercorrection. Preoperative joint geometry factors were correlated with postoperative malcorrection. Planning was conducted using the established method described by Miniaci (Group A) and with additional correction of the joint line convergence angle (JLCA) using the formula JLCA-2/2 (Group B). Additionally, in a small clinical case series, planning was conducted with JLCA correction. Statistical analysis was performed using (multiple) linear regression analysis and analysis of variance (ANOVA) with p < 0.05 considered significant. RESULTS: In 78 analysed cases, postoperative malcorrection was detected in 37.2% (5.1% undercorrection, 32.1% overcorrection). Linear regression analysis revealed preoperative body mass index (BMI, p = 0.04), JLCA (p = 0.0001), and osteotomy level divergence (p = 0.0005) as factors correlated with overcorrection. In a multiple regression analysis, JLCA and osteotomy level divergence remained significant factors. Preoperative JLCA correction reduced the planned osteotomy gap (A 9.7 ± 2.8 mm vs B 8.3 ± 2.4 mm; p > 0.05) and postoperative medial proximal tibial angle (MPTA: A 94.3 ± 2.1° vs B 92.3 ± 1.5°; p < .05) in patients with preoperative JLCA ≥ 4°. The results were validated using a virtual postoperative correction of cases with overcorrection. A case series (n = 8) with a preoperative JLCA > 4 revealed a postoperative accuracy using the JLCA correction of 3.4 ± 1.9%. CONCLUSION: Preoperative JLCA ≥ 4° and tibial osteotomy level divergence were identified as risk factors for postoperative overcorrection. Preoperative JLCA correction using the formula JLCA-2/2 is proposed to better control ideal postoperative correction and reduce MPTA. The intraoperatively realised osteotomy level should be precisely in accordance with preoperative planning. LEVEL OF EVIDENCE: III, cross-sectional study.

Satisfactory long-term outcomes for combined anterior cruciate ligament reconstruction and lateral closing wedge high tibial osteotomy.

PURPOSE: A combined anterior cruciate ligament (ACL) reconstruction and high tibial osteotomy (HTO) is considered a valuable treatment in young patients affected by symptomatic medial osteoarthritis and ACL deficiency. However, only a few studies have investigated the outcomes of this procedure, especially in the long term. Therefore, the aim of this study is to report clinical and radiographic outcomes of ACL reconstruction and lateral closing wedge HTO at a mean of 14 years of follow-up. METHODS: Patients were prospectively evaluated pre-operatively, after 6.5 ± 2.7 years and 14.3 ± 2.2 years. Patient-reported outcome measures (PROMs) were collected, knee laxity was assessed through KT-1000 arthrometer, and limb alignment and knee osteoarthritis were evaluated on long-cassette radiographs. Survivorship of the surgical procedure was calculated through the Kaplan-Meier method. RESULTS: 32 patients were initially enrolled and completed the mid-term evaluation (6.5 ± 2.7 years), and 23 patients (72%) were available for the final evaluation at 14.3 ± 2.2 years after surgery. Statistically significant improvement was found for all the clinical scores (VAS, WOMAC, Tegner, subjective IKDC, objective IKDC) between the pre-operative status and the mid-term follow-up (p < .001). VAS, subjective IKDC and objective IKDC showed no statistically significant differences (p > .05) between the mid-term and the final follow-up; a significant decrease of WOMAC (p < .05) and Tegner (p < .001) was found from mid-term to final follow-up. Significant progression of osteoarthritis was found for all the knee compartments. The survivorship was 95.7% at 5 years, 82.6% at 10 years, and 72.8% at 15 years. CONCLUSIONS: Combined ACL reconstruction and lateral closing wedge HTO showed satisfactory clinical outcomes and survivorship at a mean of 14 years follow-up. LEVEL OF EVIDENCE: IV.

No benefits of knee osteotomy patient's specific instrumentation in experienced surgeon hands.

PURPOSE: To compare the clinical and radiological outcomes of patient-specific instrumentation (PSI) with the conventional free hand (FH) technique in performing coronal plane corrective knee osteotomies in terms of limb alignment and functional scores. The hypothesis is that conventional FH technique in experienced hands with proper pre-operative planning is as precise as PSI. METHODS: Patients who underwent coronal plane corrective knee osteotomies with either PSI or FH technique between 2017 and 2019 by the same senior surgeon and have a minimum of 2 years follow-up period were included in this study. A total of 91 knees (84 patients) with mean age of 42.9 ± 12.5 years who had a pre- and post-operative complete weight-bearing radiographic work-up (50 of them were performed with the FH technique and 41 by means of PSI) were included for comparison. The data were retrospectively reviewed both radiologically and clinically using the Knee Injury and Osteoarthritis Outcome Score (KOOS) sub-scores. All cases in both groups were evaluated for the following measurements: hip-knee-ankle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), and joint line convergence angle (JLCA) both preoperatively and postoperatively. In addition, FH and PSI osteotomy cases were also compared for their precision in achieving the target correction that was planned preoperatively. All cases were also evaluated clinically preoperatively and at 2-year follow-up using KOOS sub-scores and the two groups were compared. RESULTS: The mean HKA precision was 1.5 ± 0.9 in FH group and 1.3 ± 0.7 in PSI (P value = n.s.), the mean MPTA precision was 1.6 ± 1.6 in FH group and 2.1 ± 1.2 in PSI (P value = n.s.), the mean m-LDFA precision was 1.9 ± 1.7 in FH group and 1.4 ± 1.3 in PSI (P value = n.s.), and the mean JLCA precision in the FH group was 1.5 ± 1.2 and 1.7 ± 1.2 in PSI (P value = n.s.). For all the radiographic parameters, there were no statistically significant differences between the target correction and the obtained correction in both groups. Moreover, PSI and FH techniques were comparable in terms of clinical outcomes and no significant difference was found between the two groups in any of the 2-year follow-up KOOS sub-scores. CONCLUSION: Conventional FH method in the hands of experienced surgeons is as precise as PSI in reliably achieving the planned correction in different coronal plane knee corrective osteotomies. Moreover, there was also no difference between both methods in the 2-year clinical outcome scores.

Influence of medial open wedge high tibial osteotomy on tibial tuberosity-trochlear groove distance.

PURPOSE: Medial open wedge high tibial osteotomy (MOWHTO) is an effective treatment option for realignment of a varus knee. However, a simple supra-tuberositary osteotomy can lead to patella baja and potentially increases the tibial tuberosity-trochlear groove distance (TTTG). The purpose of this study was to quantify the influence of MOWHTO on TTTG. METHODS: Three-dimensional (3D) surface models of five lower extremities with a varus hip-knee-ankle angle (HKA) and a borderline TTTG (≥ 15 mm), five lower extremities with a varus HKA and a normal TTTG (< 15 mm) and a 3D statistical shape model (SSM) of a neutrally aligned healthy knee were analysed by simulating MOWHTO with a stepwise increment of one degree of valgisation from the preoperative coronal deformity (0°-15°) for each patient, resulting in a total of 165 simulations. Postoperative 3D TTTG and tibial torsion (TT) were measured for each simulation. A mathematical formula was developed to calculate the increase of TTTG after MOWHTO. Mean differences between simulated and calculated TTTG were analysed. RESULTS: Mean preoperative HKA was 6.5 ± 3.0° varus (range 0.8°-11.5°). Mean TTTG increased from 14.2 ± 3.2 mm (range 9.6-19.1) preoperatively to 18.8 ± 3.8 mm (range 14.5-25.0) postoperatively (p = 0.001). TTTG increased approximately linear by + 0.5 ± 0.2° (range 0.3-0.8) per 1° of valgisation with a high positive correlation (0.99, p = 0.001) from 0° to 15°. Mean difference between simulated and calculated TTTG was 0.03 ± 0.02 mm (range 0.01-0.07) per 1° of valgisation (p < 0.001). CONCLUSION: MOWHTO results in an approximately linear increase in TTTG of + 0.5 mm per 1° of valgisation in the range from 0° to 15° and the lateralisation of the tibial tuberosity can be calculated reliably using the described formula. Preoperative analysis of TTTG in patients undergoing MOWHTO may prevent unintentional patellofemoral malalignment. LEVEL OF EVIDENCE: III.

Work intensity and quality of life can be restored following double-level osteotomy in varus knee osteoarthritis.

PURPOSE: The purpose of this study was to assess changes in health-related quality of life (HRQL) and work intensity following double-level knee osteotomy (DLO). It was hypothesized that postoperative HRQL would be comparable to that of the general population and that work intensity can be restored in the short term. METHODS: Twenty-four patients (28 varus knees; mechanical tibiofemoral angle: -11.0 ± 3.0° (-6.0 to -17.0), age: 49.1 ± 9.5 (31-65) years) who underwent DLO were included. The duration the patients were unable to work was evaluated. HRQL was measured with the SF-36 questionnaire, which consists of a physical (PCS) and mental component summary score (MCS). The pre- to postoperative changes in the PCS and MCS were analysed. The PCS and MCS were also compared to those of the general population, who has a reference score value of 50 points. The work intensity measured with the REFA classification and the Tegner activity scale were assessed preoperatively and at the final postoperative follow-up examination (18.0 ± 10.0 (5-43) months). RESULTS: The duration that the patients were unable to work was 12.2 ± 4.4 (6-20) weeks. The PCS improved from 32.1 ± 11.3 (14.5-53.3) preoperatively to 54.6 ± 8.5 (25.2-63.7) (p < 0.001) at the final follow-up, and the MCS improved from 53.9 ± 11.1 (17.1-67.7) to 57.2 ± 3.1 (47.3-61.7) (n.s). The preoperative PCS was significantly lower than the reference score of the general population (p < 0.001), whereas the preoperative MCS was similar between the two groups (n.s.). At follow-up, no significant differences were observed between the PCS and the MCS of the patient group and those of the general population. Five patients who were unable to work prior to surgery due to knee symptoms returned to work with moderate (four patients) or even very heavy (one patient) workloads. The Tegner activity scale increased significantly from a median of 2.0 (0.0-5.0) to 4.0 (2.0-7.0) (p < 0.001). CONCLUSION: Our results demonstrate an improvement in quality of life and return to working activity following DLO in the short term. The HRQL can be improved by DLO in patients with varus knee osteoarthritis to the level of the general population. These results can assist surgeons in discussing realistic expectations when considering patients for DLO. LEVEL OF EVIDENCE: Study type: therapeutic, IV.

Survivorship of high tibial osteotomy in the treatment of osteoarthritis of the knee: a retrospective cohort study with fourteen years' follow-up.

PURPOSE: This study was to evaluate the survivorship of HTO for the treatment of medial compartment osteoarthritis (OA) in young and active patients from two teaching hospitals in a single city. METHODS: This is a retrospective cohort multicenter study looking at HTO for treatment of medial compartment OA. We analyzed a case series of HTO's performed by four surgeons in two centres over a 14-year period. Failure was defined as conversion to total knee replacement (TKR). All cases where additional procedures for instability of the knee were performed at the time of the index surgery were excluded. Time to failure was recorded, and a Kaplan-Meir (KM) analysis was performed to evaluate survivorship. Univariate binary regression analysis was undertaken to identify associations between risk factors and failure. RESULTS: A total of 96 patients were included in the study with a median age was 45 years. The survivorship at five years post-op was 90.3%, and at ten years post-op, it was 82%. Patients that were 14 years after surgery had a survivorship of 65%. Also, 18.8% of patients required the removal of their metalwork. The overall complication rate was 6.3%. The univariate regression analysis showed that higher age (p = 0.02) and larger corrections requiring the use of bone graft increased the risk of failure (p = 0.02). There was no statistically significant correlation between laterality, gender, complication rate, and pre-operative alignment to survivorship. CONCLUSION: This is one of the largest reported case series of HTO's with comparable survivorship at five and ten year follow-up compared to the reported literature. There was an association found between increasing age and larger corrections requiring bone graft at index procedure to increasing failure rate.

Patient response to osteotomy around the knee joint at one year post-operation-fulfilment of expectations and current health status.

INTRODUCTION: The aim of this study was to investigate patient satisfaction and fulfilment of expectations after osteotomy around the knee at one year postoperatively, using patient-related outcome measures. MATERIALS AND METHODS: From the initial sample of 264 patients, a total of 132 patients (age 48y ± 11) were enrolled in this prospective study (response rate 49.3%). Data were collected using the Hospital For Special Surgery-Knee Surgery Expectations Survey (HFSS-KSES), items for satisfaction and the Knee injury and Osteoarthritis Outcome Score (KOOS) measures. At one year postoperative follow-up, an individualized questionnaire asked whether the specific person-related expectations had been fulfilled. RESULTS: Satisfaction was high with 83.2% of all participants at one year after surgery. A total of 78% of patients stated they would decide to do the surgery again. This decision was significantly associated with satisfaction, younger age and better KOOS scores scales before surgery for pain, activity and sports. We found high correlations between satisfaction and fulfilment of expectations for the HFES-KSES. Fulfilment of expectations one year after surgery was significantly associated with significant improvements in KOOS scales at one year post-operation. Expectations (1) "to get the knee back to normal status", (2) "improve ability to squat", (3) "improve ability to run", (4) "improve ability to kneel" had been fulfilled worst. A multiple linear regression model for satisfaction had an R2 = 0.797 of the variance. The most influential was the variable fulfilment of "maintain health" that had 70.7% of variance. CONCLUSIONS: The fulfilled expectation concerning an improvement of the ability to maintain health was the most influential parameter for satisfaction at one year post-osteotomy. Patients with better health status of the knee and younger age rated the surgery to be more positive and were also more likely to do the surgery again. This provides an indication for an earlier intervention, before the knee and overall health status becomes more detrimental. LEVEL OF EVIDENCE: Level II (Therapeutic study).

Bone healing on serial plain radiographs occurs slowly but adequately after medial opening wedge high tibial osteotomy without bone graft.

PURPOSE: The purpose of this study was to prospectively investigate osteotomy gap filling rates on serial plain radiographs, and to evaluate whether alignment correction is maintained after medial opening wedge high tibial osteotomy (MOWHTO) using a locking plate without bone graft. METHODS: Between March 2014 and June 2017, MOWHTO was performed without bone graft regardless of gap size. Radiographs were taken preoperatively, postoperatively, at 1, 3, 6, 12, 18, and 24 months after surgery. Radiographic examinations included a weight bearing long-standing anteroposterior (AP) view of the whole lower extremity, as well as, the AP, lateral, and both oblique views of the knee. Bone healing was measured on the medial oblique view of the knee. The postoperative alignment correction and its maintenance were assessed using the three radiologic parameters of the weight-bearing line (WBL) ratio, the hip-knee-ankle angle (HKAA), and the medial proximal tibial angle (MPTA) on the weight-bearing long-standing AP view of the lower extremity. RESULTS: Fifty-two consecutive patients underwent MOWHTO, but three patients failed to follow-up for more than 24 months. A total of 49 patients were assessed in this study. The median opening gap height was 10.0 mm (IQR, 8.0-12.0; range, 7-20). On immediate post-operative radiographs, the mean gap filling was 31.4 ± 3.6%. After 1, 3, 6, 12, 18, and 24 months, the mean gap filling rates increased to 38.7 ± 4.4%, 51.4 ± 6.6%, 66.5 ± 5.1%, 84.8 ± 7.0%, 92.4 ± 5.6%, and 97.8 ± 2.3%, respectively. Statistical differences were observed between all the follow-up evaluations (P < 0.001). Statistical differences in the WBL ratio, HKAA, and MPTA were observed between preoperatively and 1 month after surgery (P < 0.001). The mean PTSA increased significantly from preoperatively to postoperatively (P < 0.001). However, no statistical differences were found between the post-operative follow-up radiographs performed for these four values. CONCLUSION: MOWHTO using a locking plate without bone graft achieved at least 90% bone healing and had no loss in correction at 2 years postoperatively. LEVEL OF EVIDENCE: III.

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

PURPOSE: The 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). METHODS: A 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 dependent t tests. RESULTS: From 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. CONCLUSION: In 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 EVIDENCE: Level III.

Transverse osteotomy closer to tibial plateau is associated with larger postoperative change in valgus laxity after open-wedge high tibial osteotomy.

PURPOSE: To identify the factors impacting changes in valgus laxity between before and after open-wedge high tibial osteotomy (OW-HTO) using quantitative valgus stress radiographs. METHODS: A total of 40 knees from 38 patients who underwent OW-HTO were assessed. The study population comprised 14 men and 24 women, with a mean age of 61.5 years. Valgus stress radiographs before and 1 year after OW-HTO were performed using a Telos device. The difference between pre- and postoperative joint line convergence angle (JLCA) was expressed as ΔJLCA (post-pre). As indicators of the proximal detachment of superficial medial collateral ligament (sMCL) on radiographs, two distances were defined: the distance from the level of the osteotomy starting point to the tangent line of the proximal tibial plateau (Distance A), or to the medial edge of the proximal tibial plateau (Distance B). Correlations between ΔJLCA and radiographic parameters or KOOS sub-scores were assessed using Spearman's rank correlation coefficient analysis. Receiver operator curves were generated to evaluate the predictive strength of the significant factor for an increase in ΔJLCA > 1°. RESULTS: Pre-operative OA severity consisted of Kellgren-Lawrence grade 2 (n = 18), 3 (n = 16), and 4 (n = 6). The average ΔJLCA (post-pre) was 0.5°, and ranged from - 1.4° to + 3.0°. The maximum systemic measurement error and limits of agreement were 0.07° and 0.20°, respectively. There were significant correlations between ΔJLCA and Distance A (36.9 ± 3.9 mm, R = - 0.46, p = 0.002), between ΔJLCA and Distance B (39.9 ± 4.0 mm, R = - 0.49, p = 0.001). The cut-off value for Distance A was determined to be 35 mm below the tibial plateau; the AUC was 0.804, with a sensitivity of 0.75 and a specificity of 0.82. Distance B correlated strongly with Distance A (R = 0.96, p < 0.001). There was no significant correlation between ΔJLCA and KOOS sub-scores 1 year after OW-HTO. CONCLUSIONS: Transverse osteotomy closer to tibial plateau was associated with larger valgus joint laxity postoperatively. This finding implies that sMCL proximal detachment, which was related to the level of the osteotomy starting point on the proximal tibia, potentially affected postoperative valgus laxity. LEVEL OF EVIDENCE: IV.

The use of tranexamic acid reduces blood loss in osteotomy at knee level: a systematic review.

PURPOSE: Aim of this systematic review was to evaluate the literature regarding the effect of tranexamic acid (TXA) on the outcome after knee osteotomy. METHODS: A systematic literature search was carried out in various databases on studies on the use of tranexamic acid in osteotomies around the knee. Primary outcome criterion was the hemoglobin (drop). Secondary outcome criteria were total blood loss, drainage volume, adverse effects such as thromboembolic events, blood transfusions, wound complications and clinical scores. A meta-analysis was performed for quantitative measures. The present study was registered prospectively ( www.crd.york.ac.uk/PROSPERO ; no.: CRD42021229624). RESULTS: Seven studies with 584 patients (TXA group: 282 patients, non TXA group: 302 patients) Hemoglobin decrease (1.54 g/dl vs. 2.28 g/dl), blood loss (394.49 ml vs. 595.54 ml) and drainage volume (266.5 ml vs. 359.05 ml) were significantly less in the TXA group compared to the non TXA group. No thromboembolic event was noted in any study. In the non TXA group four blood transfusions were given. Eleven wound complications occurred in the non TXA group in comparison to two wound complications in the TXA group. CONCLUSIONS: The results of the present study show that the application of TXA reduces hemoglobin drop, blood loss and drainage volume. These effects could be responsible for the lesser rate of side effects after administration of TXA during knee osteotomy.

Consistent indications, targets and techniques for double-level osteotomy of the knee: a systematic review.

PURPOSE: To systematically review and critically appraise the literature on double-level osteotomy (DLO) of the knee, and determine the indications, contraindications, targets and outcomes. MATERIALS AND METHODS: A systematic literature search was performed on PubMed, Embase®, and Cochrane for studies that reported on DLO by any technique or approach, including indications, contraindications, and targets for DLO, as well as patient-reported outcome measures (pROMS) and radiographic angles. RESULTS: Twelve eligible studies were found: 9 case series and 3 studies that compared DLO to high-tibial osteotomy (HTO). In all studies, DLO was performed by medial opening-wedge tibial osteotomy and lateral closing-wedge femoral osteotomy. Seven specified that DLO was performed if simple HTO would exceed thresholds of postoperative medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), and/or predicted wedge size. The targets were 88°-95° for MPTA, 84°-89° for LDFA, and 0°-4° for hip-knee-ankle (HKA) angle. The 3 comparative studies reported lower MPTA after DLO (89.6°-92.5°) than after HTO (91.5°-98.3°). All 3 reported similar postoperative HKA after DLO (0.2°-4.4°) as HTO (0.4°-4.8°); only 2 compared postoperative LDFA, which was lower after DLO (85.4° and 84.9°) than HTO (88.7° and 88.8°). Two comparative studies reported postoperative overall KOOS which was slightly lower after DLO (351-403) than HTO (368-410); only 1 study reported separate items of the KOOS. CONCLUSION: There was relative consistency between studies on the indications, targets and techniques for DLO. Furthermore, while the comparative studies reported similar preoperative MPTA, LDFA and HKA, the postoperative MPTA and LDFA were lower after DLO than after HTO, though both treatments achieved equivalent postoperative HKA. LEVEL OF EVIDENCE: IV, systematic review.