Search

Varus knees with associated cartilage pathologies are not uncommon scenarios that present to orthopaedic surgeons. There is no agreement on the ideal management of varus knees with concomitant cartilage pathology. Through a literature review, the authors tried to answer three main questions: On October 2022, OVID MEDLINE, EMBASE, and COCHRANE databases were searched. Clinical studies reporting on clinical, radiologic, or macroscopic cartilage regeneration following either isolated knee osteotomy or concomitant osteotomy and a cartilage procedure were reviewed. Despite controversies, the literature demonstrated favourable outcomes of combined knee osteotomy and a cartilage procedure in patients with substantial deformity and cartilage defects. Isolated high tibial osteotomy may induce cartilage regeneration in several scenarios and severities of concomitant malalignment and cartilage defects. There are recommendations that knee osteotomy should be added to a cartilage procedure when an extra-articular deformity of > 5° is detected. Some studies report good outcomes for combining a knee osteotomy with cartilage grafting, but they lack a control group of isolated osteotomy. There is still scarce of evidence on the influence of osteotomies on cartilage regeneration and the outcomes of concomitant osteotomy and different cartilage procedures vs isolated osteotomies. With advanced statistical evaluation (artificial intelligence, machine learning) of big datasets, more answers and better results will be delivered.

Abstract Mortality related to femoral neck fractures remains a challenging health issue, with a high mortality rate at 1 year of follow-up. Three modifiable factors appear to be under control of the surgeon: the choice of the implant, the use of cement and the timing before surgery. The aim of this research project was to study the impact on mortality each of these risk factors play during the management of femoral neck fractures. A large retrospective epidemiological study was performed using a national database of the public healthcare system. The inclusion criteria were patients who underwent joint replacement surgery after femoral neck fracture during the years 2015 to 2017. All data points were available for at least 2 years after the fracture. The primary outcome was mortality within 2 years following the surgery. We evaluated the association between mortality and the type of the implant hemiarthroplasty (HA) versus total hip arthroplasty (THA), cemented versus non cemented femoral stem as well as the timing from fracture to surgical procedure. A multivariate analysis was performed including age, gender, comorbidities/autonomy scores, social category, and obesity. We identified 96,184 patients who matched the inclusion criteria between 2015 and 2017. 64,106 (66%) patients underwent HA and 32,078 (33.4%) underwent THA. After multivariate analysis including age and comorbidities, patients who underwent surgery after 72 h intra-hospital had a higher risk of mortality: Hazard Ratio (HR) = 1.119 (1.056–1.185) p = 0.0001 compared to the group who underwent surgery within 24 h. THA was found to be a protective factor HR = 0.762 (0.731–0.795) p

Background: Excessive posterior tibial slope (PTS) has been associated with a higher risk of graft failure after anterior cruciate ligament reconstruction (ACLR). Although anterior closing wedge osteotomy (ACWO) can reduce the PTS, it may also change the coronal alignment and patellar height. Purpose: To elucidate the radiological outcomes after infratubercle ACWO, specifically to evaluate its influence on perioperative changes in patellar height. Methods: Patients who underwent infratubercle ACWO with combined ACLR with a minimum follow-up of 3 months were included. Surgery was indicated when the PTS was greater than 12°. Radiological evaluation included measurements of the hip–knee–ankle angle (HKA), PTS, femoral patellar height index (FPHI), and Caton–Deschamps index (CDI) preoperatively and 3 months postoperatively. Patellar height was classified as patella baja, normal, or alta based on CDI values. Knee recurvatum was measured preoperatively and at final follow-up. Results: A total of 21 patients with a mean age of 21.6 ± 3.0 years were included. Although HKA did not significantly change, significant corrections were achieved in the PTS from 14.5° ± 1.6° to 5.7° ± 1.0° (p < 0.001). No significant change in FPHI was found (preoperative: 1.33 ± 0.11 vs postoperative: 1.30 ± 0.09). Patellar height categories showed no significant differences pre- and postoperatively, while three patients (14.3%) changed their patellar height category (all moved up one category). Knee recurvatum increased significantly from 4.9° ± 2.9° preoperatively to 7.8° ± 3.1° at the final follow-up (p < 0.001). Conclusions: Precise sagittal correction was achieved after infratubercle ACWO without altering the coronal alignment and patella height. Level of Evidence: IV, Case series.

Abstract Purpose To compare the accuracy of patient‐specific guides (PSCG) to the standard technique in medial open‐wedge high tibial osteotomy (OWHTO). Secondary objectives were to evaluate factors that could influence accuracy and to compare the complication rate and operating time for both procedures. Methods A retrospective analysis of prospective collected data was performed. Between March 2011 and May 2018, 49 patients with isolated medial knee osteoarthritis who were operated for OWHTO using PSCG and 38 patients using the standard technique were included. Preoperative and postoperative deformities were evaluated on long leg radiographs by measuring the mechanical medial proximal tibial angle, mechanical lateral distal femoral angle, hip knee ankle angle (HKA), and joint line convergence angle. Pre‐ and postoperative posterior tibial slope was also evaluated. Accuracy was evaluated by analysing the difference between the preoperative planned and the actual postoperative HKA. Operating time and complication rate were also recorded in both groups. Results The mean preoperative HKA was 173.4° (±3.1°) in the PSCG group and 173.3° (±2.4°) in the standard group (p = 0.8416). Mean planned HKA were 182.8° (±1.1°) and 184.0° (±0°) respectively for the PSCG and the standard group. Mean postoperative HKA were 181.9° (±1.9°) and 182.6° (±3.1°) respectively for the PSCG and the standard group. An accuracy of ±2° in the HKA was achieved in 44 (90%) in the PSCG group and 24 (65%) in the standard group (p = 0.006). The probability of achieving a HKA accuracy was four times higher for patients in the PSCG group (odds ratio [OR] = 4.06, [1.1; 15.3], p = 0.038). Also, higher preoperative Ahlback grade was associated with precision, all other parameters being equal (OR = 4.2, [0.13; 0.97], p = 0.04). Conclusion In this study, the PSCG technique was significantly more accurate for achieving the planned HKA in OWHTO. Complication rates and operating times were comparable between groups. Level of Evidence Level IV, case‐control study.

Aims: The impact of a diaphyseal femoral deformity on knee alignment varies according to its severity and localization. The aims of this study were to determine a method of assessing the impact of diaphyseal femoral deformities on knee alignment for the varus knee, and to evaluate the reliability and the reproducibility of this method in a large cohort of osteoarthritic patients. Methods: All patients who underwent a knee arthroplasty from 2019 to 2021 were included. Exclusion criteria were genu valgus, flexion contracture (> 5°), previous femoral osteotomy or fracture, total hip arthroplasty, and femoral rotational disorder. A total of 205 patients met the inclusion criteria. The mean age was 62.2 years (SD 8.4). The mean BMI was 33.1 kg/m2 (SD 5.5). The radiological measurements were performed twice by two independent reviewers, and included hip knee ankle (HKA) angle, mechanical medial distal femoral angle (mMDFA), anatomical medial distal femoral angle (aMDFA), femoral neck shaft angle (NSA), femoral bowing angle (FBow), the distance between the knee centre and the top of the FBow (DK), and the angle representing the FBow impact on the knee (C’KS angle). Results: The FBow impact on the mMDFA can be measured by the C’KS angle. The C’KS angle took the localization (length DK) and the importance (FBow angle) of the FBow into consideration. The mean FBow angle was 4.4° (SD 2.4; 0 to 12.5). The mean C’KS angle was 1.8° (SD 1.1; 0 to 5.8). Overall, 84 knees (41%) had a severe FBow (> 5°). The radiological measurements showed very good to excellent intraobserver and interobserver agreements. The C’KS increased significantly when the length DK decreased and the FBow angle increased (p < 0.001). Conclusion: The impact of the diaphyseal femoral deformity on the mechanical femoral axis is measured by the C’KS angle, a reliable and reproducible measurement. Cite this article: Bone Jt Open 2023;4(4):262–272.

Background: It is estimated that surgical procedures account for 20%-30% of the greenhouse gases emissions from health-care systems. Total knee replacements (TKR) are one of the most frequently performed procedures in orthopaedics. The aim of this study was to identify and quantify the environmental impacts generated by TKRs, the factors that generate the most emissions, and those that can be easily modified. Methods: To calculate the life cycle carbon footprint of a posterior stabilized cemented TKR performed in a single orthopaedic surgery department, 17 TKRs performed between October 12 and 20, 2020 by 4 senior surgeons were analysed. The analysis of the life cycle included the manufacture of the implant, from raw materials to distribution; the journey made by patients and staff; and the surgery including all consumables required to facilitate the procedure. Results: The overall life cycle carbon footprint of a single TKR was 190.5 kg of CO2. This consisted of 53.7 kg CO2 (28%) for the manufacture of the prosthesis, 50.9 kg CO2 (27%) for travel, 57.1 kg CO2 (30%) for surgery, and 28.8 kg CO2 (15%) for waste management. This is comparable to a New York-Detroit direct flight. Conclusions: The production of a total knee prosthesis, throughout its life cycle, generates emissions with important consequences on the environment and therefore on our health. Although much data are currently missing to make precise estimates, and especially regarding benefits in terms of patient function and its impact on carbon emissions, these data serve as a starting point for other more detailed or comparative studies.

Aims: Two-stage exchange revision total hip arthroplasty (THA) performed in case of periprosthetic joint infection (PJI) has been considered for many years as being the gold standard for the treatment of chronic infection. However, over the past decade, there have been concerns about its safety and its effectiveness. The purposes of our study were to investigate our practice, collecting the overall spacer complications, and then to analyze their risk factors. Methods: We retrospectively included 125 patients with chronic hip PJI who underwent a staged THA revision performed between January 2013 and December 2019. All spacer complications were systematically collected, and risk factors were analyzed. Statistical evaluations were performed using the Student's t-test, Mann-Whitney U test, and Fisher's exact test. Results: Our staged exchange practice shows poor results, which means a 42% mechanical spacer failure rate, and a 20% recurrent infection rate over the two years average follow-up period. Moreover, we found a high rate of spacer dislocation (23%) and a low rate of spacer fracture (8%) compared to the previous literature. Our findings stress that the majority of spacer complications and failures is reflecting a population with high comorbid burden, highlighted by the American Society of Anesthesiology grade, Charlson Comorbidity Index, and Lee score associations, as well as the cardiac, pulmonary, kidney, or hepatic chronic conditions. Conclusion: Our experience of a two-stage hip exchange revision noted important complication rates associated with high failure rates of polymethylmethacrylate spacers. These findings must be interpreted in the light of the patient’s comorbidity profiles, as the elective population for staged exchange has an increasing comorbid burden leading to poor results. In order to provide better results for this specific population, our conclusion suggests that comparative strategy studies are required to improve our therapeutic indication. Cite this article: Bone Jt Open 2022;3(6):485–494.

Introduction: In cases of symptomatic knee valgum, in which deformity majorly originated in the femoral distal metaphysis, 2 main types of femoral osteotomy have been described: medial closing or lateral opening. We have been doing medial closing wedges with anterior second plane cut for years. The reason being a proven similar surgical accuracy associated to a higher and faster healing rate promoted by a larger contact area between the 2 sides of the osteotomy site. The aim of this article is to describe up-to-date closing wedge distal femoral osteotomy strategies: from indication, to ideal correction, surgical technique and patient recovery. Methods: Distal femoral varus osteotomy is indicated in painful valgus knee in which deformity originated majorly in the femoral distal metaphysis. The planning is digitally performed according to the Miniaci method using digital software to have a postoperative weight bearing line passing through the knee joint at 45% to 50% measured from the medial tibial plateau border (0%) to the lateral tibial plateau border (100%). The procedure is performed through medial closing wedges created with 2 medial to lateral and 1 posterior to anterior cutting planes creating an anterior biplanar cut. Results: Using our step-by-step way to perform closing wedge distal femoral osteotomy, we standardized our radiological and clinical outcomes. Knowing some tips and tricks to avoid intraoperative complications will help readers to master this procedure. Conclusions: Following simple intraoperative landmark and technical guidance bony deformity can be fully corrected by medial closing wedges using an anterior biplanar cut. Patients will demonstrate optimal clinical outcomes including high rate of return to recreational and professional activities.

Abstract Proximal tibial osteotomy (PTO) is an effective procedure for active and young adult patients with symptomatic unicompartmental osteoarthritis and malalignment. They were considered technically demanding and prone to various complications related to the surgical technique, biomechanical or biological origin. Among the most important are hinge fractures and delayed or non‐healing, neurovascular complications, loss of correction, implant‐related problems, patellofemoral complaints, biological complications and changes in limb length. Being aware of these problems can help minimizing their prevalence and improve the results of the procedure. The aim of this narrative review is to discuss the potential complications that may occur during and after proximal tibial osteotomies, their origin and ways to prevent them.

Abstract Purpose The Pivot Shift (PS) test is a complex clinical sign that assesses the internal rotation and anterior tibial translation, which occurs abnormally in ACL deficient‐knees. Because of the high inter‐observer variability, different devices have been designed to characterize this complex movement in quantitative variables. The objective of this pilot study is to validate the reproducibility of intraoperative quantitative assessment of the PS with a smartphone accelerometer. Methods Twelve ACL‐injured knees were included and compared with the contralateral uninjured side. The PS was measured by two independent observers utilizing a smartphone accelerometer and graded according to the IKDC classification. Measurements were taken preoperatively, intraoperatively and postoperatively. Intraoperative readings were taken during each stage of reconstruction or repair of meniscoligamentous lesions including meniscal lesions, ramp lesions, ACL reconstruction and lateral tenodesis. Reproducibility of the measurements were evaluated according to an intraclass correlation coefficient (ICC). Results The intra‐observer reliability was good for the first examiner and excellent for the second examiner, with the ICC 0.89 [0.67, 0.98] p

Minimally invasive double-level osteotomy (DLP) surgery is performed in severe knee varus, when extra-articular deformity is identified in both the distal femur and proximal tibia. The main advantage is to maintain a horizontal joint line and avoid creating secondary anatomic deformities. This article considers the pearls and pitfalls in performing minimally invasive DLO surgery.

Abstract The joint line convergence angle (JLCA) has a normal range between 0° to 2°, which increases in magnitude depending on the severity and stage of osteoarthritis in the knee. The JLCA represents the interaction of the intra-articular deformity arising from the osteoarthritis and the surrounding soft tissue laxity. Therefore, the JLCA has become a vital parameter in analysing the long leg alignment views for corrective planning before osteotomy surgery. Recent studies have considered the influence on how the preoperative JLCA is measured and its influence on achieving accurate postoperative desired correction in high tibial osteotomy surgery. The JLCA also reflects the influence of soft tissue laxity in a lower limb malalignment and many surgeons encourage it to be taken into account to avoid non physiological correction and/or overcorrection with negatively impacted postoperative patient outcome. This present review addressed how to obtain an accurate preoperative measurement of the JLCA, its influence on postoperative deformity analysis and how to reduce errors arising from an elevated preoperative JLCA. We have proposed a formula to help determine the value to subtract from the planned correction in order to avoid an overcorrection when performing a corrective osteotomy. Level of clinical evidence IV, narrative review.

Abstract Purpose The aim of our cadaveric study was to compare the mechanical properties of different parts of the quadriceps’ tendon in a load to failure analysis as compared to three other, and most common types of grafts that are used to perform ligament’s reconstruction. Methods Ten fresh-frozen cadavers (5 women, 5 men) were selected from our anatomical department. Mean age at death was 64 years (48–87 years). Tendons were harvested to prepare (1) different quadriceps tendon’s specimens: lateral portion (QTlat), medial portion superficial layer (QTMsup) and deep layer (QTMdeep) and central portion superficial (QTCsup) and deep layers (QTCdeep) (2) Patellar Tendon (PT), (3) Gracilis+Semi-Tendinosus specimens (GST). Specimens were stored at − 40 °C in a freezing solution. Specimens were securely attached to a dedicated loading platform, measurements were done using a validated software. Load to failure testing was then carried out. Young’s Elastic moduli, ultimate Stress (MPa) and Deformation (%) were analysed. Results The elastic moduli of the PT was significantly higher than all other grafts, all medial and central QT layers (superficial and deep) were significantly higher than its lateral part (QTlat). In terms of Ultimate Stress, all grafts were significantly greater than QTlat, PT and GST were significantly superior to QT central portions and to ITB but there did not differ with the medial portion of QT. ITB ultimate stress values were significantly higher than QTlat. The ultimate deformations of all grafts were similar. Conclusions This study provides reference values in in order to characterize different parts of the QT that presents anatomically and Mechanically with complex characteristics. Every Layer of Quadriceps Tendon’s Central and Medial Portion Offered Similar Mechanical Properties than Two Strand Hamstrings or Ilio-Tibial Band.

Abstract The roadmap to elective surgery resumption after this COVID-19 pandemic should be progressive and cautious. The aim of this paper was to give recommendations and guidelines for resuming elective orthopedic surgery in the safest environment possible. Elective surgery should be performed in COVID-free facilities and hospital stay should be as short as possible. For matters of safety, patients considered first for surgery should be carefully selected according to COVID infection status/exposure, age, ASA physical status classification system / risk factors, socio-professional situation and surgical indication. A strategy for resuming elective surgery in four phases is proposed. Preoperative testing for COVID-19 infection is highly recommended. In any cases, COVID symptoms including fever and increased temperature should be constantly monitored until the day of surgery. Elective surgery should be postponed at the slightest suspicion of a COVID-19 infection. In case of surgery, adapted personal protective equipment in terms of gowns, gloves, masks and eye protection is highly recommended and described.

Background: Inadequate deformity analysis and planning before high tibial osteotomy (HTO) may result in correction errors with unsatisfactory clinical results. Indications: The purpose of this article is to describe the deformity analysis and preoperative planning before HTO. This surgery is effective for young patients with compartmental mild knee osteoarthritis. A partial deformity analysis without considering the femoral or intra-articular deformity may lead to overcorrection or excessive joint line obliquity. Preoperative planning using the Miniaci method with manual or semiautomated digital measures may help to prevent these types of errors. Technique Description: Landmarks are used at the proximal femoral side, distal condyles, proximal tibial plateau, and talus borders to define angles automatically on PeekMed software. Fujisawa point is determined to be 50% of the length of the proximal tibia, and Miniaci method is performed after defining the weightbearing line. The method can be performed manually or semiautomatically with the software. In this last case, the optimal procedure to be done to correct the malalignment is proposed by the software which automatically does the opening of the osteotomy to match the desired weightbearing axis and displays the size of the wedge in millimeters. Results: The intraobserver and interobserver reproducibility were performed by 2 different analyses and 2 different observers. The precision of the measures was confirmed based on computed tomographic (CT) scan 3-dimensional measures defined as the gold standard. All the intraobserver and interobserver reproducibility correlation coefficients and precision were satisfactory compared with the gold standard. Hip-knee-ankle angle may vary because of weightbearing situations between CT and long-axis x-rays. Discussion/Conclusion: The interest of semiautomated software for angular value measurements is now well recognized, and the inclusion of anatomical landmarks allows accurate and reproducible angular value measurements. Automatic knee osteotomy planning analyzes the metaphyseal deformity of both the tibia and the femur, and the software suggests the optimal procedure with the degree of openness to obtain the desired mechanical axis without creating excessive joint line obliquity

Medial opening wedge high tibial osteotomy (OW-HTO) is an excellent surgical option for patients with varus knee osteoarthritis. This article presents a technique of performing a minimally invasive OW-HTO using a patient-specific cutting guide (PSCG). Preoperative 3-dimensional planning with computed tomography imaging is essential. The correction parameters, the final plate position, as well as the 3-dimensional position of the hinge as well as wedge are verified preoperatively before the PSCG is produced. After exposure with an oblique incision over the posteromedial tibia, the hamstring tendons are released for later re-attachment and the medial collateral ligament is released slightly. The PSCG is then used to perform the OW-HTO with protection of the posterior neurovascular structures by a retractor placed posterior to the medial collateral ligament. The final fixation of the osteotomy is achieved with a low-profile locking plate and a femoral head allograft wedge.

Medial opening-wedge high tibial osteotomy (OW-HTO) is an excellent surgical option for patients with varus knee osteoarthritis. Medial collateral ligament (MCL) release and posterior neurovascular structure protection during OW-HTO are steps that often induce stress and nervousness during surgery, especially for surgeons in the earlier stages of their learning curve. While is it well-known that the MCL should be released during OW-HTO, the standard retraction techniques pose challenges in visualization and instrument placement in the surgical field. We present our technique, which illustrates an alternative method to manage the MCL and safely protect the neurovascular structures using a second and more posterior surgical window during OW-HTO.

Patellar lower-pole fractures occur in relatively young patients after eccentric contraction of the quadriceps or direct trauma. Early diagnosis and adequate treatment lead to excellent outcomes and prevent tendon retraction and scarring. The aim of surgical treatment is to restore articular congruence and reestablish the extensor mechanism of the knee. All surgical treatments (sutures and tension band wiring, separate vertical wiring or augmented with Krackow sutures, wiring through screws, basket plate, hook plate) use additional hardware. We propose a hardware-free technique using ipsilateral hamstring augmentation.

Abstract Purpose The aim of this paper was to report the results presented in the session “Does practice of meniscus surgery change over time?” of the 2021 MENISCUS webinar held online on January 30th 2021. Method During the 2021 MENISCUS webinar, an evaluation of meniscus surgery practices was performed by analyzing: (1) The presentation of the results of a survey conducted among ESSKA members and assessing their current practices in the field of meniscus surgery, (2) Four reports by national experts analyzing the trends in Arthroscopic Partial Meniscectomy (APM) and meniscus repair procedures in their respective countries (France, Belgium, Germany and Japan). Results (1) ESSKA Survey: Among the 461 respondents, 75% of surgeons claimed to perform more meniscus repairs and 85% less APM than 5 years ago. In ACL‐associated meniscus injuries, a majority of surgeons (60%) indicated to perform a meniscal resection in less than 25% of cases. 25% declared to perform meniscus repair in ACL‐associated meniscus injuries in less than 25% of cases and 37% in more than 50% of cases. Half of the respondents repair medial or lateral root tears in less than 25% of cases. Less than 20% of respondents were not familiar with the ESSKA consensus. (2) National trends: In France, between 2005 and 2017, the APM rate decreased by 21.4%, while the repair rate increased by 320%. In Belgium, between 2007 and 2017, the APM rate decreased by 28.6%. In Germany, between 2010 and 2017 the number of APM decreased by 30%, while the number of repair procedures increased by 55%. Finally, in Japan, between 2011 and 2016, the APM ratio (APM/meniscus procedures) decreased by 16% from 91 to 75% while the repair ratio increased from 9 to 25%. Conclusion The 2021 ESSKA members' survey as well as statistics from 4 specifically examined countries (Belgium, France, Germany and Japan) suggest there has been a significant shift over the last years in the surgical management of meniscal lesions towards less APM and more conservative treatments.

The purpose of this study was to determine the distribution of functional knee phenotypes in a non-osteoarthritic Asian population. The Stryker Orthopaedic Modeling and Analytics (SOMA) database was searched for CT scans of the lower limb meeting the following inclusion criteria: patient age at time of image >18 and p < 0.001) but a higher FMA (males p < 0.05, females p < 0.001) than Caucasian knees but showed no difference in the HKA. Asian knees differed significantly with regard to femoral and tibial phenotypes (p < 0.01), but not with regard to limb phenotypes. The high variability of all coronal alignment parameters highlights the importance of a detailed analysis prior to TKA. Ethnical differences underline the need for a more individualized approach in TKA.

Anterior cruciate ligament reconstruction after graft failure may need associated bone correction to ensure stability of the knee. This article presents a technique of posteromedial opening-wedge osteotomy using a custom cutting guide to correct increased tibial slope and metaphyseal varus deformity after recurrent graft failure. An autograft quadriceps tendon graft was selected for the revision anterior cruciate ligament graft. After exposure with an anteromedial incision a patient specific cutting guide was used to make the high tibial osteotomy. The final fixation of the posteromedial opening was achieved using a low-profile locking plate and a femoral head allograft bone wedge. The tibial tunnel was planned and included in the patient-specific cutting guide. The femoral tunnel was placed using an outside to in manner. Bioabsorbable screws were used as fixation devices.

Abstract Background The aim of this in vitro study was to assess the accuracy of three-dimensional patient-specific cutting guides for open wedge high tibial osteotomy (OWHTO) to provide the planned correction in both frontal and sagittal planes. Methods Ten cadaveric tibias underwent OWHTO performed using a patient-specific cutting guide based on 3D preoperative planning. An initial CT scan of the tibias was performed, and after segmentation, 3D geometrical models of the pre-OWHTO tibias were obtained. Reference planes were defined, and OWHTO virtually planned to then design patient-specific cutting guides. OWHTO were performed using the patient-specific cutting guides. The patient-specific cutting guide controls the cut and the correction of the OWHTO in both planes. 3D models of post-OWHTO tibias were created after a postoperative CT scan. Geometrical post-OWHTO 3D models were superimposed on pre-OWHTO 3D models. Mechanical medial proximal tibial angle (mMPTA) in the frontal plane and posterior tibial slope (PTS) in the sagittal plane were compared between planned-OWHTO and post-OWHTO 3D reconstructions relative to the pre-OWHTO reference planes and axis. Pearson’s and Lin’s correlation tests were performed to assess precision and accuracy of patient-specific cutting guides. Results The mean difference between post-OWHTO and planned-OWHTO was 0.2° (max 0.5°, SD 0.3°) in the frontal plane and − 0.1° (max 0.8°, SD 0.5°) in the sagittal plane. Statistically significant correlations were found between the planned-OWHTO and post-OWHTO configurations for the mMPTA (p