Medial Opening Research Articles

A Computer-Assisted Approach Regarding the Optimization of the Geometrical Planning of Medial Opening Wedge High Tibial Osteotomy

Opening wedge high tibial osteotomy (OWHTO) is a surgical procedure often used to eliminate the effects of knee osteoarthritis, a disease that is becoming more widespread worldwide. Optimizing the geometric planning of this operation is a very important preparatory step for the success of the intervention and rapid postoperative recovery. This optimization is performed in two main directions. The first direction evaluates the intraoperative behavior of the tibia during the osteotomy by optimizing four geometric parameters that characterize geometric planning. The second direction aims at a postoperative evaluation of the flat tibia-osteosynthesis assembly taking into account the optimal position on the medial–lateral articular line through which the corrected mechanical axis of the tongue passes and implicitly offloads the transfer from the medial area to the side of the knee. The research methods used are exclusively computer-assisted such as: computer-aided design (hereinafter CAD) for geometric modeling of the tibia taking into account the real bone structure, the finite element method (hereinafter FEM) for performing numerical analyses and design of the experiment (hereinafter DOE) for the design of the research. The results obtained are eloquent and clearly presented and can be important elements for orthopedic doctors at the geometric planning stage of the OWHTO.

Effect of the Inverted V-Shaped Osteotomy on Patellofemoral Joint and Tibial Morphometry as Compared With the Medial Opening Wedge High Tibial Osteotomy

Background: Recent studies have reported that medial opening wedge (OW) high tibial osteotomy (HTO) induces patella baja, resulting in degenerative changes in the patellofemoral joint. We have developed an inverted V-shaped (iV) HTO, which is classified as a neutral wedge osteotomy. Hypotheses: The study hypotheses were as follows: (1) patellar height, posterior tibial slope, and tibial length will not change between pre- and postoperative evaluations after iV-HTO; (2) the lateral shift ratio of the patella and the distance between the tibial tubercle and the trochlear groove may be significantly decreased after iV-HTO. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 191 patients (220 knees) who underwent HTO for medial osteoarthritis were enrolled retrospectively in this study: 107 knees underwent OW-HTO and 113 knees underwent iV-HTO. Clinical and radiological evaluations were performed before and at least 3 years after surgery. Results: Postoperatively, the mean Caton-Deschamps ratio was significantly decreased (P < .0001) from 0.95 to 0.79 in the OW group, while there were no significant changes in the iV group. The mean posterior tibial slope was significantly increased (P < .0001) from 8.5° to 10.5° in the OW group, while there were no significant differences in the iV group. Although the entire leg length was significantly increased (P < .0003) in both groups after HTO, there were no significant differences in tibial length between the pre- and postoperative periods in the iV group. Regarding the congruity of the patellofemoral joint, the mean lateral shift ratio did not significantly change in the OW group, whereas it was significantly decreased (P = .0012) from 11.5% to 8.8% in the iV group. The mean tibial tubercle–trochlear groove distance was significantly decreased (P < .0001) from 12.8 to 9.7 mm in the iV group, while it was significantly increased in the OW group (P < .0001). Concerning the clinical outcome, the Japanese Orthopaedic Association (JOA) and Lysholm knee scores at final follow-up (OW vs iV: JOA, 91.2 vs 90.1; Lysholm, 92.5 vs 89.0) were significantly increased (P < .0001) as compared with the preoperative values (OW vs iV: JOA, 68.3 vs 66.8; Lysholm, 67.9 vs 61.0). Conclusion: Patellar height, posterior tibial slope, and tibial length did not change after the iV-HTO, while they were significantly changed after the OW-HTO. Although the preoperative degrees of varus knee and patellofemoral osteoarthritis were more severe in the iV group than the OW group, the iV-HTO led to altered patellofemoral joint congruity.

Basics of Coronal Plane Deformity Correction

High tibial osteotomy (HTO) and distal femoral osteotomy (DFO) are utilized to correct knee malalignment in patients with coronal plane deformities. Identifying the deformity of the lower extremity using a standardized, reproducible approach is critical prior to correction of lower limb malalignment with an osteotomy procedure. Appropriate radiographs, including bilateral long-leg standing films, are critical to measure the anatomical and/or mechanical axes and calculate the required degree of correction. The femoral and tibial mechanical axes, malalignment (varus or valgus), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA) should be measured during coronal plane deformity analysis and accounted for during surgical planning. This paper focuses on the surgical technique for medial opening and lateral closing wedge HTO, as well as medial closing and lateral opening wedge DFO.

Role of Osteotomy in Ligament Injuries: Updates on Corrective Osteotomy Combined Ligament Procedure Techniques

Proximal tibial osteotomies are an effective treatment option for addressing knee instability secondary to alignment-based overload on ligamentous structures. Proximal tibial osteotomies effectively alter the mechanical axis to redistribute forces across the knee, resulting in improved stability and overall function. Factors such as tibial slope and coronal alignment can affect the biomechanical forces experienced by the ligaments in the knee. This becomes especially important when treating recurrent instability following primary reconstruction of one or more of the ligaments of the knee. A variety of osteotomy procedures exist to address a wide range of alignment disorders. These include proximal tibial closing wedge osteotomies, anterolateral opening wedge osteotomies, anterolateral opening wedge osteotomies, and proximal tibial medial opening wedge osteotomies. Recently, the indications of medial opening wedge osteotomies have been expanded to include treatment of chronic central and posterolateral ligament instability. Early rehabilitation in the recovery phase should focus on limb protection, symptom management, protected range of motion, quadriceps muscle activation, and monitoring for overall patient well-being. Clear guidelines for safe quadriceps training progressions following osteotomy do not exist due to the paucity of biomechanical literature. The patient should gradually progress through the transition and rebuild phases of recovery over the first 24 weeks following surgery. Patients may not progress into the restore phase of rehabilitation as this population typically completes the second stage of the 2-stage ligamentous reconstruction during the latter half of the Rebuild phase once sufficient healing from the first procedure has occurred. Currently, data regarding clinical outcomes and return to sport data following PTO for knee instability is limited.

Radiographic evaluation of the bicipital groove morphology does not predict intraarticular changes in the long head of biceps tendon

Introduction and objectivesThis study aimed to examine the clinical utility of the radiographic evaluation of the bicipital groove in predicting long head of biceps tendon (LHBT) pathology. Material and methodsA prospective study was conducted, and sixty consecutive patients proposed to shoulder arthroscopic surgery were selected. Before surgery, a radiographic evaluation was performed with a supine and a Fisk radiograph. Most supine radiographs (>75%) were non-interpretable and were excluded from the study. As some Fisk radiographs (26.7%) were also non-interpretable, that left 44 interpretable radiographs in the study. These were measured for medial opening angle, total opening angle, width and depth of the bicipital groove. The radiographic measurements and the presence of LHBT pathology, as assessed at arthroscopy, were correlated. ResultsRadiographic evaluation of the bicipital groove showed a mean medial opening angle of 53 ± 15° (23–90), a mean total opening angle of 80 ± 26° (30–135), a mean width of 10.3 ± 2.5 mm (6–19) and a mean depth of 4.1 ± 1.5 mm (1–8). Men had higher medial opening angle (60 vs 50°, p = 0.044) and wider grooves (11.9 vs 9.7 mm, p = 0.019). Twenty-five patients (56.8%) were found to have an abnormal LHBT. No correlation was found between the radiographic measurements and LHBT pathology. Only age was correlated with a LHBT lesion (61.8 vs 46.3 years, p < 0.001). ConclusionsOur results show that there is no correlation between radiographic morphologic evaluation of the bicipital groove and LHBT pathology.

High Tibial Osteotomy Using the ‘Tomofix™’ Plating System: Short Term Outcomes in Young Adults

Proximal tibial valgus osteotomy is one of the treatment options for painful medial compartment osteoarthritis and varus deformity of the knee. The aim of our study was to determine and quantify how much osteotomy altered symptoms from medial compartment gonoarthrosis. In addition we aimed to establish whether the Tomofix plating system would permit early weight bearing and achieve union without the use of bone grafts. We prospectively analysed our experience with medial opening wedge high tibial osteotomy using the Tomofix plate.&#x0D; Thirty-five knees were included in the study. The mean age was 47 years (36-59 years). Mean duration of follow-up was 23 months (7-48 Months). All patients underwent medial opening wedge high tibial osteotomy using the Tomofix plating system. Data was recorded using the Oxford Knee score, the Knee Injury Osteoarthritis Outcome score and through review of pre and postoperative x-rays. Good outcomes were seen with statistically significant improvement of both scores.&#x0D; There were two delayed unions, the remainder united without requirement for graft. There was improvement, in Oxford and Knee injury osteoarthritis scores. Correction of mal-alignment was seen in all cases. Early weight bearing was found to be permissible without risk of adverse event.&#x0D; The Tomofix plate provided immediate stability and satisfactory healing of the osteotomy site without the need for bone graft. Good functional results were seen.

A Biomechanical Comparison of the LaPrade Technique Versus a Novel Technique for Reconstruction of Medial-Sided Knee Injuries

Background: Medial-sided knee injuries can lead to symptomatic valgus laxity or anteromedial rotatory instability and may require surgery, particularly in the setting of cruciate tears and tibial-sided medial collateral ligament (MCL) avulsions. The LaPrade (LP) technique utilizes 2 free grafts to reconstruct the superficial MCL (sMCL) and the posterior oblique ligament (POL). An alternative MCL reconstruction devised by the senior author comprises an anatomic single-bundle reconstruction using a free graft to reconstruct the sMCL with advancement and imbrication of the posteromedial capsule/POL (MCL anatomic reconstruction with capsular imbrication [MARCI] technique). These techniques have not been biomechanically compared with one another. Purpose: To identify if one of these reconstruction techniques better restores valgus and rotational medial knee stability throughout the range of motion. Study Design: Controlled laboratory study. Methods: A total of 20 fresh-frozen, male (mean age, 43.7 years [range, 20-63 years]), midfemur-to-toe-matched cadaveric knees were utilized. All reconstructions were performed by a single fellowship-trained sports medicine surgeon. Left and right specimens within matched pairs were randomized to 1 of the 2 treatment groups: LP or MARCI. Each specimen was tested in 3 phases: (1) intact knee, (2) destabilized (MCL and POL completely severed), and (3) reconstructed (post-LP or post-MARCI reconstruction). We quantified valgus angulation defined by medial joint line opening, as well as internal and external tibial rotation at 0°, 20°, 30°, 60°, and 90° of knee flexion under applied external moments/torques at each phase. Results: There were significant differences between the MARCI and LP reconstruction groups in valgus stability compared with the intact state (P = .021), with the MARCI reconstruction more closely approximating the intact knee. There was no overall difference between the MARCI and LP reconstruction techniques for internal rotation (P = .163), with both closely resembling the intact state. For external rotation, the effect of the reconstruction technique was dependent on the knee flexion angle (P < .001). At the highest angles, there were no differences between reconstructions; however, for lower knee flexion angles, the MARCI technique more closely resembled the intact state. Conclusion: Although both techniques improved knee stability compared with destabilized conditions, the MARCI technique better approximated intact stability during valgus at knee flexion angles from 0° to 90° and external rotation loads at knee flexion angles ≤30° in a cadaveric model. Clinical Relevance: The MARCI technique provides an alternative option to improve valgus stability throughout the range of motion. It utilizes a POL advancement without the potential limitations seen in the LP technique, such as multiple tunnel complexity and collision, particularly in the multiple ligament–injured knee.

Accuracy, inter- and intrarater reliability, and user-experience of high tibial osteotomy angle measurements for preoperative planning: manual planning PACS versus semi-automatic software programs

PurposeTo compare the accuracy, inter- and intrarater reliability, and user-experience of manual and semi-automatic preoperative leg-alignment measurement planning software for high tibial osteotomy (HTO).MethodsThirty patients (31 lower limbs) who underwent a medial opening wedge HTO between 2017 and 2019 were retrospectively included. The mechanical lateral distal femur angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and planned correction angle were measured on preoperative long-leg full weight-bearing radiographs utilising PACS Jivex Review® v5.2 manual and TraumaCad® v2.4 semi-automatic planning software. Independent measurements were performed by four raters. Two raters repeated the measurements. Accuracy in the standard error of measurement (SEM), inter- and intrarater reliability, and user-experience were analysed. Additionally, measurements errors of more than 3° were remeasured and reanalysed.ResultsThe SEMs of all measured varus malalignment angles and planned correction angle were within 0.8° of accuracy for both software programs. Measurements utilising the manual software demonstrated moderate interrater intraclass correlation coefficient (ICC)-values for the mLDFA and mMPTA, and an excellent interrater ICC-value for the correction angle (0.810, 0.779, and 0.981, respectively). Measurements utilising the semi-automatic software indicated excellent interrater ICC-values for the mLDFA, mMPTA, and correction angle (0.980, 0.909, and 0.989, respectively). The intrarater reliability varied substantially per angle, presenting excellent intrarater agreements by both raters (ICC > 0.900) for the correction angle in each software program as well as poor-to-excellent ICC-values for the mLDFA (0.282–0.951 and 0.316–0.926) and mMPTA (0.893–0.934 and 0.594–0.941) in both the manual planning and semi-automatic software. Regarding user-experience, semi-automatic software was preferred by two raters, while the other two raters had no distinctive preference. After remeasurement of five outliers, excellent interrater ICC-values were found for the mLDFA (0.913) and mMPTA (0.957).ConclusionsSemi-automatic software outperforms the manual software when user-experience and outliers are considered. However, both software programs provide similar performance after remeasurement of the human-related erroneous outliers. For clinical practice, both programs can be utilised for HTO planning.Level of evidenceDiagnostic study, Level III.

What can influence the outcome of open wedge high tibial osteotomy?

Objective – to assess the effect of patient-specific parameters (age, body mass index (BMI), stage of the knee osteoarthritis (KOA), the osteotomy gap size, concomitant medial opening angle high tibial osteotomy (MOWHTO) arthroscopic plastic (AP) and open chondroplasty (OCHP) on the development of complications and the outcome of the operation.Materials and methods. The study included 76 patients who underwent MOWHTO. To study the influence of each of the parameters, comparison groups were created: 1) by age: patients younger and older than 60 years (45 versus 31); 2) by BMI: patients with BMI&lt;30 kg/m2 versus patients with a BMI from 30 to 40 kg/m2 (35 versus 41); 3) by the osteotomy gap size: ≤10 mm and &gt;10 mm (29 versus 47); 4) by stages of KOA: patients with stage I and II versus patients with stage III (43 versus 33); 5) patients with MOWHTO + AP of the knee or OCHP versus patients who underwent only MOWHTO (34 versus 42). To assess the result, we studied the change in pain intensity according to the visual analogue scale (VAS), as well as the state of the knee joint according to the Knee Society Score (KSS) scale before surgery and 1 year after MOWHTO.Results. The development of complications had a weak direct relationship with stage III of the KOA (r=–0.24) and moderate strength a direct relationship with the osteotomy gap size &gt;10 mm (r=–0.42). Age, BMI, the presence of concomitant AP of the knee or OCHP did not affect the development of complications. However, the number of complications was statistically significantly higher among patients with stage III and osteotomy gap size &gt;10 mm relative to patients with stage II of the KOA (p=0.03) and patients with deformity correction ≤10 mm (p=0.0002). Age over 60 years and BMI&lt;30 kg/m2 had a direct weak relationship (r=0.27 and r=0.23) with the achievement of a satisfactory result. An excellent result had a direct weak relationship with a BMI&lt;30 kg/m2 and stages I–II of the KOA (r=0.34 and r=0.31), as well as a direct moderate strength relationship with an osteotomy gap size ≤10 mm (r=0.46). At the age of patients over 60 years, a satisfactory result was significantly more frequent compared with patients of young and middle age (p=0.016). 71.1% of excellent results were obtained in patients with a BMI&lt;30 kg/m2 (p=0.002), and there were significantly more good and satisfactory results in the group of patients with a BMI&gt;30 kg/m2 (p=0.08 and p=0.04). At stage III, an excellent result was obtained 3 times less frequently than in patients with stages I and II of the KOA (p=0.004). In patients with gap size ≤10 mm, excellent results were 1.5 times greater than in patients with a gap size &gt;10 mm (p=0.00006). There were no differences in the results in patients who underwent MOWHTO in isolation and in patients in whom MOWHTO was supplemented with AP of the knee or OCHP.Conclusions. The development of complications is associated with stage III of the KOA and the need for correction (the osteotomy gap size) &gt;10 mm. The best result of MOWHTO can be obtained in patients under the age of 60 years, with a BMI &lt;30 kg/m2 at stages I–II of the KOA and deformity correction within 10 mm. Concomitant AP of the knee or OCHP don’t affect the development of complications and the outcome of the operation.

Medial meniscus extrusion and stage are related to the size of spontaneous osteonecrosis of the knee in patients who underwent high tibial osteotomy

PurposeSpontaneous osteonecrosis of the knee (SONK) causes acute atraumatic knee pain, and meniscus tears may be associated with the pathogenesis of SONK. The purpose of this study was to investigate the relationship of the type of meniscus tear and medial meniscus extrusion with SONK on the medial femoral condyle in patients who underwent surgical treatment with high tibial osteotomy due to severe knee pain. MethodsWe enrolled 98 patients with 102 knees who underwent medial opening wedge high tibial osteotomy (OWHTO) under the diagnosis of medial femoral condyle osteonecrosis at our hospital from December 2003 to January 2020. Based on the Koshino classification, cases of SONK were classified as stage 1–4. The relationships of demographic data, X-rays and MRI images, including femorotibial angle (FTA), meniscus tear type, and medial meniscus extrusion (MME), with the stage and volume of SONK were investigated. ResultsNinety-eight patients (29 males and 69 females), with an average age at surgery of 69.2 ± 9.6 years and Body mass index(BMI) of 61.0 ± 17.6 kg/m2. In 102 cases of SONK, 11 knees, 18 knees, 46 knees, and 27 knees were classified as stage 1–4, respectively. The mean SONK volume was 2161.61 µm (range 95.67–7484.68 µm) on preoperative MRI. The preoperative FTA (mean 180.86°, range 172–187°) was not associated with the stage or volume of SONK. Meniscus tears were found in all cases of SONK and consisted of 2 degenerations, 2 horizontal tears, 0 vertical tears, 40 radial tears, 4 complex tears, and 54 medial meniscus posterior root tears (MMPRTs). In addition, 99% (101/102) of knees showed more than 3 mm of meniscus extrusion. Although the meniscus tear type was not associated with SONK stage, there was a high rate of tears that caused disruption of the hoop strain, such as MMPRTs (52.9%) or radial tears (39.2%). MME was significantly related to SONK volume (r = 0.387, p < 0.001). ConclusionAll patients with SONK had coexisting meniscus tears, most menisci had medial extrusion, and a positive correlation was observed between MME and SONK volume.

Extreme Hinge Axis Positions Are Necessary to Achieve Posterior Tibial Slope Reduction With Small Coronal-Plane Corrections in Medial Opening Wedge High Tibial Osteotomy.

Background:Both coronal- and sagittal-plane knee malalignment can increase the risk of ligamentous injuries and the progression of degenerative joint disease. High tibial osteotomy can achieve multiplanar correction, but determining the precise hinge axis position for osteotomy is technically challenging.Purpose:To create computed tomography (CT)–based patient-specific models to identify the ideal hinge axis position angle and the amount of maximum opening in medial opening wedge high tibial osteotomy (MOWHTO) required to achieve the desired multiplanar correction.Study Design:Descriptive laboratory study.Methods:A total of 10 patients with lower extremity CT scans were included. Baseline measurements including the mechanical tibiofemoral angle (mTFA) and the posterior tibial slope (PTS) were calculated. Virtual osteotomy was performed to achieve (1) a specified degree of PTS correction and (2) a planned degree of mTFA correction. The mean hinge axis position angle for MOWHTO to maintain an anatomic PTS (no slope correction) was 102.6° ± 8.3° relative to the posterior condylar axis (PCA). Using this as the baseline correction, the resultant hinge axis position and maximum opening were then calculated for each subsequent osteotomy procedure.Results:For 5.0° of mTFA correction, the hinge axis position was decreased by 6.8°, and the maximum opening was increased by 0.49 mm for every 1° of PTS correction. For 10.0° of mTFA correction, the hinge axis position was decreased by 5.2°, and the maximum opening was increased by 0.37 mm for every 1° of PTS correction. There was a significant difference in the trend-line slopes for hinge axis position versus PTS correction (P = .013) and a significant difference in the trend-line intercepts for maximum opening versus PTS correction (P < .0001).Conclusion:The mean hinge axis position for slope-neutral osteotomy was 102.6° ± 8.3° relative to the PCA. For smaller corrections in the coronal plane, more extreme hinge axis positions were necessary to achieve higher magnitudes of PTS reduction.Clinical Relevance:Extreme hinge axis positions are technically challenging and can lead to unstable osteotomy. Patient-specific instrumentation may allow for precise correction to be more readily achieved.

"One millimetre equals one degree": a simple way to achieve in 92% of cases the desired correction after opening proximal tibial osteotomy for genu varum.

When performing a high tibial osteotomy (HTO) for genu varum deformity, it is not always easy to obtain the correct amount of overcorrection. The aims of this study were to review the results of a simple and reproducible method of correction that we have called "1mm equals 1°". We have applied this technique to the medial opening wedge osteotomy. Our hypothesis was that one degree of correction corresponded with one degree of opening. 97 proximal medial opening wedge osteotomies were measured intraoperatively with a navigation system and at 3months with long-leg X-rays. The hip-knee-ankle (HKA) angle preoperatively was on average 173.8 ± 2.3° (170°-177°). In most cases, an opening of 4° greater than the initial varus was performed using our formula that one degree varus was equal to 1mm of opening. In other words, when the varus was 6°, an opening of 10mm was performed. The void left by the opening wedge was filled with a calcium triphosphate wedge and the construct fixed and held with a locking plate. Aiming for a knee axis of 184 ± 2°, which corresponds to 2°-6° of overcorrection, we obtained the following results: HKA intraoperatively measured angle with navigation was on average 183.5 ± 0.9° (182°-184°) and HKA radiologically postoperatively angle was 182.5° ± 1.6° (179°-189°). We therefore achieved the desired overcorrection of 2°-6° in 92% of cases based on our postoperative radiographs and in 100% cases based on intraoperative measurements with computer navigation. The method of "1mm equals 1°" is a simple, reliable, and reproducible method to achieve in 92% of cases the desired overcorrection (i.e., 184 ± 2°) with valgising proximal medial opening wedge osteotomy in genu varum.

Changes in coronal alignment of the hip joint after medial opening wedge high tibial osteotomy

PurposeAn observation was made by the senior author of this paper that patients reported changes in their hip function after a medial opening wedge high tibial osteotomy (MOHTO) for varus pattern osteoarthritis. Alignment changes at the hip after MOHTO have not been previously documented. This study assesses coronal alignment changes at the hip after MOHTO.MethodsWe retrospectively analysed pre- and post-operative lower limb alignment radiographs of patients who underwent MOHTO. The medial proximal tibial angle (MPTA) and mechanical axis deviation (MAD) were measured to assess the alignment changes created by the MOHTO. The coronal alignment changes at the hip were evaluated using the mechanical greater trochanter angle (MGTA).Results29 osteotomies in 27 patients were included in this study. Results showed MOHTO created alignment changes at the hip. A positive correlation was found between the size of the correction at the knee and the subsequent changes at the hip. The change in the MGTA had a stronger correlation with the MAD than with the change in MPTA (r = 0.684 vs. 0.585). It was found that age, weight, height and BMI had no significant influence on these correlations.ConclusionsIncreased correction by the MOHTO lead to increased change in the coronal alignment of the hip. These changes are likely to result in an alteration in the weight bearing portion of the femoral head and the function of the abductors and we recommend assessing the hip joint as part of pre-operative planning.Level of evidencePrognostic level IV.

Analyse de survie et facteurs d’échec de 167 ostéotomies tibiales proximales d’ouverture médiale avec plaque verrouillable en titane

IntroductionThis retrospective study investigated the survival rate and complications of medial opening wedge high tibial osteotomy (MOWHTO) with a precountered titanium locking plate. HypothesisAdvanced age (≥50 years), gender, body mass index (BMI), type of osteotomy cut (monoplanar or biplanar), osteoarthritis (OA) grade, the use of bone grafting or substitution and preoperative hip-knee-ankle (HKA) have impact on MOWHTO survival. Material and methodsA total of 167 knees (155 patients) were consecutively operated during the study period of 01.01.2006–31.12.2014. The primary outcome measure was survival without a need for revision to total knee arthroplasty (TKA). The secondary outcome was a major adverse event leading to revision surgery. Adverse events and complications were evaluated and radiological analyses were done. Furthermore, risk factors that affected the survival were analysed with the Cox regression model. ResultsThe mean follow-up time was 7.7 (SD 2.7, range 0.9–14.5) years. The Kaplan-Meier estimates for the cumulative survival considering no need for TKA after MOWHTO was 90% at 5 years, 78% at 10 years and 61% at 14.5 years (SE 0.4, 95%CI 11.2–12.9). The adverse event rate was 30% and 35% of the patients required a secondary surgery. The Cox regression model did not show that age, gender, weight, osteotomy type, the use of bone grafting or substitution, preoperative HKA angle or OA grade were not risk factors for conversion to arthroplasty. DiscussionMOWHTO with locking plate provides good survival with no need for TKA in 78% of the knee medial OA patients at 10 years of cumulative follow-up. However, a high adverse event rate (30%) is expected. Risk factors for conversion to TKA were not found and thereby hypothesis of this study was not proved. Level of ProofVI; Retrospective cohort study.

Intramedullary Nailing for Atypical Femoral Fracture With Lateral Bowing: Does Medial Gap Matter?

IntroductionWhen performing intramedullary nailing for atypical femoral fractures (AFF), especially in lateral bowing femurs, a medial opening wedge-shaped gap in the fracture site may occur after nailing. We intended to analyse and compare clinical outcomes according to the medial gap in AFF cases after intramedullary nailing. Materials and Methods: Of the 38 consecutive patients with complete AFF treated by intramedullary nailing, 22 patients (all female, mean age of 76.5 years [range, 62–87]) available for follow-up for more than 12 months were included. According to the size of the medial gap, the patients were divided into 2 groups: large and small medial gaps. Comparative analysis was performed between groups in terms of patient, fracture characteristics and post-operative clinical outcomes. Results: There was no significant difference in bone union time between the 2 groups (5.4 months vs 5.6 months, P = .628). When comparing the amount of change in the hip–knee–ankle angle after the surgery with reference to the contralateral side, there was a significant difference between the 2 groups (−4.4° [femoral straightening and relatively changed to a more valgus pattern, that is, in cases of varus alignment, towards neutral alignment] vs .5°, P = .002). There was no significant difference in leg length discrepancy between the 2 groups (4.1 mm vs 3.2 mm, P = .674). In terms of functional outcomes, there was no significant difference in the recovery of ambulatory ability (ΔKoval grade: post-operative Koval grade–pre-operative Koval grade, 0 vs .1, P = .771). Conclusion: Even if the medial gap occurs following intramedullary nailing in AFF, post-operative clinical outcomes seem to be acceptable. However, if previous total knee arthroplasty is performed and neutral alignment is maintained, care should be taken as the occurrence of the gap may result in lower limb malalignments.

Two-Step 3D-Guided Supramalleolar Osteotomy to Treat Varus Ankle osteoarthritis.

Success of valgus-type supramalleolar osteotomy (SMOT) depends on adequate correction of malalignment, which can be hard to achieve with current 2-dimensional (2D) planning and operative techniques. A personalized digital 3-dimensional (3D) workflow to virtually plan and perform a 2-step 3D-guided medial opening (MO) SMOT has the potential to improve precision of correction. Computed tomography (CT)-based Proplan medical 3D models were made to virtually plan the desired MO SMOT, and exported to 3-Matic medical to develop patient-specific 2-step cutting and wedge guides. Workflow accuracy was tested in this limited clinical pilot study (3 patients) by comparing the virtual planned position of the osteotomized distal tibial fragment with the 1-year post-MO SMOT configuration. Two millimeters or less translation deviation in every plane was defined as accurate. Primary outcome analysis of the osteotomized distal tibial fragment deviation showed a median translation in all planes of 0.7 (range 0-8.2) mm (interquartile range 1.55) with an excellent interrater reliability of the measurements (intraclass correlation coefficient 0.998). There was a strong reduction in ankle pain as reflected by an increase of the AOFAS-AH score and decrease of NRS pain score with an unrestricted hindfoot motion 1 year after surgery. 3D virtually planned bone cutting and wedge guides is a promising approach associated with minimal postoperative deviation from the desired correction in medial opening supramalleolar osteotomy.

Assessment of Medial Open Wedge High Tibial Osteotomy in Management of Medial Compartment Osteoarthritis of The Knee

Assessment of Medial Open Wedge High Tibial Osteotomy in Management of Medial Compartment Osteoarthritis of The Knee

The 3-triangle method preserves the posterior tibial slope during high tibial valgus osteotomy: first preliminary data using a mathematical model

PurposeDespite much improved preoperative planning techniques accurate intraoperative assessment of the high tibial valgus osteotomy (HTO) remains challenging and often results in coronal over- and under-corrections as well as unintended changes of the posterior tibial slope. Noyes et al. reported a novel method for accurate intraoperative coronal and sagittal alignment correction based on a three-dimensional mathematical model. This is the first study examining preliminary data via the proposed Noyes approach for accurate intraoperative coronal and sagittal alignment correction during HTO.MethodsFrom 2016 to 2020 a total of 24 patients (27 knees) underwent HTO applying the proposed Noyes method (Noyes-Group). Radiographic data was analyzed retrospectively and matched to patients that underwent HTO using the conventional method, i.e., gradual medial opening using a bone spreader under fluoroscopic control (Conventional-Group). All operative procedures were performed by an experienced surgeon at a single orthopaedic university center.ResultsFrom the preoperative to the postoperative visit no statistically significant changes of the posterior tibial slope were noted in the Noyes-Group compared to a significant increase in the Conventional-Group (p = 0.01). Regarding the axial alignment no significant differences between both groups were observed pre- and postoperatively. The number of over- and under-corrections did not differ significantly between both groups. Linear regression analysis showed a significant correlation of the postoperative medial proximal tibial angle (MPTA) with the position of the weightbearing line on the tibial plateau.ConclusionThe 3-triangle method by Noyes seems to be a promising approach for preservation of the posterior tibial slope during HTO.

A novel 3D-printed patient-specific instrument based on \u201cH-point\u201d for medial opening wedge high tibial osteotomy: a cadaver study

BackgroundOpening wedge high tibial osteotomy (OWHTO) is an effective surgical treatment for knee osteoarthritis. This study aimed to explore the feasibility and accuracy of a novel 3D-printed patient-specific instrument (PSI) based on “H-point” for medial OWHTO in a prospective cadaver study.MethodsTwenty-six fresh-frozen lower limbs were collected and randomly divided into two groups: PSI group treated with 3D virtual preoperative planning and a novel 3D-printed PSI; control group with the standard technique. 3D models were reversely reconstructed for preoperative surgical planning, guide plate design, and simulated osteotomy. Anatomic features of “H-point,” surgical time, fluoroscopic dose, correction accuracy including tibiofemoral angle (FTA) and posterior tibial slope (TS) angle were measured.ResultsFirst, H-point was always described as a bony bulge in the posteromedial to the proximal tibia and had a relatively constant relationship with the osteotomy site. Second, the absolute correction error of mFTA and TS were significantly smaller in the PSI group. The effective rate of TS in the PSI group was more concentrated with absolute correction error within 1° and within 2° for 53.3% and 93.3%, compared to 9.1% and 45.5% in the control group. The total operation time, positioning osteotomy time, distraction correction time and fluoroscopy dose in the PSI group were significantly less than those in the control group.ConclusionsThe novel 3D-printed PSI based on H-point is feasibility and accuracy with advantages in terms of TS, surgery time and radiation dose for OWHTO.

Factors Associated with Postoperative Knee Joint Line Obliquity After Medial Open Wedge High Tibial Osteotomy

Background: There are still few reports on factors associated with postoperative knee joint line obliquity (KJLO). Purpose: The purpose was to determine preoperative radiographic factors that are associated with KJLO postoperatively after open wedge high tibial osteotomy (OWHTO) using multivariable linear regression analysis and multivariable logistic regression analysis. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 60 patients with 65 varus knees who underwent OWHTO between December 2012 and June 2018 at a single institution were retrospectively enrolled in this study. The authors evaluated radiologic parameters including the weightbearing line ratio, femorotibial angle, medial proximal tibial angle, mechanical lateral distal femoral angle (LDFA), lateral distal tibial angle, joint line convergence angle (JLCA), KJLO, and ankle joint obliquity. They also categorized these radiographic parameters as preoperative and postoperative and calculated the difference (Δ) between preoperative and postoperative values. To determine which of the radiographic parameters were most associated with postoperative KJLO, multivariable linear regression analysis was performed using the stepwise method. Multivariable logistic regression analysis was used to examine the relative contribution of the preoperative radiographic parameters to an abnormal postoperative KJLO (>4°). Results: In the multivariable linear regression analysis, the preoperative LDFA and JLCA showed a statistically significant correlation. Multivariable logistic regression analysis revealed that the mean preoperative LDFA was significantly larger in the group with abnormal KJLO than in the group with the control group (odds ratio, 1.84; 95% CI, 1.12-3.02; P = .02), while preoperative JLCA tended to be larger in the abnormal KJLO group than the control group but not statistically significantly different. Conclusion: KJLO after OWHTO was associated with preoperative LDFA and JLCA in multivariable linear regression analysis, and preoperative LDFA was the most important factor associated with abnormal KJLO after OWHTO in multivariable logistic regression analysis.