Posterior Slope Reducing Osteotomy With Concomitant Anterior Cruciate Ligament Reconstruction

Background: Modern techniques for graft choice, preparation, and fixation for anterior cruciate ligament (ACL) reconstruction demonstrate excellent longevity and return-to-play rates; however, up to 10% to 18% of cases continue to suffer reruptures, with even higher rates in specific subsets of patients. Indications: Normally, the posterior tibial slope is measured between 7° and 10°, with biomechanical and observational studies showing that posterior slope greater than 12° increases the risk of graft failure by 5× by allowing for increased anterior tibial translation, putting increased stress on the graft. The primary indication for a slope correction osteotomy with a revision ACL reconstruction is a patient with tibial slope greater than 12° who has failed prior ACL reconstruction. Technique Description: In our preferred technique, we illustrate a slope reducing anterior closing wedge proximal tibial osteotomy with concurrent revision ACL reconstruction rather than a staged ACL reconstruction. Results: The primary benefit of this technique is the ability to correct the tibial slope and reconstruct the ACL in one setting, which decreases recovery time, costs, and risks to the patients by eliminating an additional procedure. Discussion/Conclusion: In cases of ACL reconstruction failure, particularly in patients with multiple failures, an increased posterior tibial slope may be a contributing factor. Anterior closing wedge osteotomy has been shown to be an effective treatment, in patients with a native slope greater than 12°. A slope reducing anterior closing wedge proximal tibial osteotomy with concurrent revision ACL reconstruction rather than a staged ACL reconstruction has a wide array of benefits.

Feasibility study of early prediction of postoperative MRI findings for knee stability after anterior cruciate ligament reconstruction

Background At present, the most effective and mature treatment after ACL injury and tear is ACL reconstruction, but the rehabilitation process after ACL reconstruction that is very long, so it is very important to find early MRI positive findings of knee instability. Methods We retrospectively collected the clinical and imaging data of 70 patients who underwent ACL reconstruction from January 2016 to December 2019; Based on clinical criteria, the patients were divided into a stable group (n = 57) and an unstable group (n = 13); We measured the MRI imaging evaluation indexes, including the position of the bone tunnel, graft status, and the anatomical factors; Statistical methods were used to compare the differences of imaging evaluation indexes between the two groups; The prediction equation was constructed and ROC curve was used to compare the prediction efficiency of independent prediction factors and prediction equation. Results There were significant differences in the abnormal position of tibial tunnel entrance, percentage of the position of tibial tunnel entrance, position of tibial tunnel exit, lateral tibial posterior slope (LTPS), width of intercondylar notch between stable knee joint group and unstable knee joint group after ACL reconstruction (P < 0.05); The position of tibial tunnel exits and the lateral tibial posterior slope (LTPS) and the sagittal obliquity of the graft were independent predictors among surgical factors and self-anatomical factors (P < 0.05); The prediction equation of postoperative knee stability was established: Logit(P) = -1.067–0.231*position of tibial tunnel exit + 0.509*lateral tibial posterior slope (LTPS)-2.105*sagittal obliquity of the graft; The prediction equation predicted that the AUC of knee instability was 0.915, the sensitivity was 84.6%, and the specificity was 91.2%. Conclusions We found that abnormalities of the position of the exit of the bone tunnel, lateral tibial posterior slope (LTPS) and sagittal obliquity of the graft were the early MRI positive findings of knee instability after ACL reconstruction. It is helpful for clinicians to predict the stability of knee joint after ACL reconstruction.

Posterior tibial slope measurement among Saudi population

To measure the posterior slope of the tibia among the healthy Saudi population using Magnetic Resonance Imaging (MRI). A retrospective study review of 151 knee MRIs at King Khaled University Hospital, Riyadh, Saudi Arabia. All patients with no previous surgical intervention to their knees and did not suffer any bone injury around the knee were included. Three different orthopedic physicians (two senior residents, one orthopedic fellow) measured the posterior tibial slope (PTS) angle for all patients, and their average was taken for all readings using a sagittal T2 MRI cut. Patients with a history of previous surgical intervention to the knee joint, trauma involving distal femur or proximal tibia, osteoarthritis and inflammatory arthritis, and congenital deformities were excluded from the study. The mean age of patients was 28.15 in a range of 15-50 years. The posterior tibial slope mean and the median and the mode were 8.76, 8.73, 7.53, respectively. In addition, the mean angle (degree) in females was 9.69±4.02 and 8.76±4.15 in males. The Maximum and the minimum posterior slope angle calculated in these patients were respectively 19.73 and 0.3 degrees. Our findings are that the mean posterior tibia slope among the Saudi population is 8.76˚. The results showed the difference of PTS in Saudi people comparing to deferent communities. The association between the numbers of the posterior tibial slope with gender was tested and no significant correlation. In this study, we did not calculate weight and height in the cases as independent factors. Because of that, upcoming studies might consider these factors.

Restoring the Patient’s Pre-Arthritic Posterior Slope Is the Correct Target for Maximizing Internal Tibial Rotation When Implanting a PCL Retaining TKA with Calipered Kinematic Alignment

Introduction: The calipered kinematically-aligned (KA) total knee arthroplasty (TKA) strives to restore the patient’s individual pre-arthritic (i.e., native) posterior tibial slope when retaining the posterior cruciate ligament (PCL). Deviations from the patient’s individual pre-arthritic posterior slope tighten and slacken the PCL in flexion that drives tibial rotation, and such a change might compromise passive internal tibial rotation and coupled patellofemoral kinematics. Methods: Twenty-one patients were treated with a calipered KA TKA and a PCL retaining implant with a medial ball-in-socket and a lateral flat articular insert conformity that mimics the native (i.e., healthy) knee. The slope of the tibial resection was set parallel to the medial joint line by adjusting the plane of an angel wing inserted in the tibial guide. Three trial inserts that matched and deviated 2°> and 2°< from the patient’s pre-arthritic slope were 3D printed with goniometric markings. The goniometer measured the orientation of the tibia (i.e., trial insert) relative to the femoral component. Results: There was no difference between the radiographic preoperative and postoperative tibial slope (0.7 ± 3.2°, NS). From extension to 90° flexion, the mean passive internal tibial rotation with the pre-arthritic slope insert of 19° was greater than the 15° for the 2°> slope (p < 0.000), and 15° for the 2°< slope (p < 0.000). Discussion: When performing a calipered KA TKA with PCL retention, the correct target for setting the tibial component is the patient’s individual pre-arthritic slope within a tolerance of ±2°, as this target resulted in a 15–19° range of internal tibial rotation that is comparable to the 15–18° range reported for the native knee from extension to 90° flexion.

Robotic-assisted total knee arthroplasty improves accuracy and precision compared to conventional techniques

Aims Robotic-assisted total knee arthroplasty (RA-TKA) is theoretically more accurate for component positioning than TKA performed with mechanical instruments (M-TKA). Furthermore, the ability to incorporate soft-tissue laxity data into the plan prior to bone resection should reduce variability between the planned polyethylene thickness and the final implanted polyethylene. The purpose of this study was to compare accuracy to plan for component positioning and precision, as demonstrated by deviation from plan for polyethylene insert thickness in measured-resection RA-TKA versus M-TKA. Methods A total of 220 consecutive primary TKAs between May 2016 and November 2018, performed by a single surgeon, were reviewed. Planned coronal plane component alignment and overall limb alignment were all 0° to the mechanical axis; tibial posterior slope was 2°; and polyethylene thickness was 9 mm. For RA-TKA, individual component position was adjusted to assist gap-balancing but planned coronal plane alignment for the femoral and tibial components and overall limb alignment remained 0 ± 3°; planned tibial posterior slope was 1.5°. Mean deviations from plan for each parameter were compared between groups for positioning and size and outliers were assessed. Results In all, 103 M-TKAs and 96 RA-TKAs were included. In RA-TKA versus M-TKA, respectively: mean femoral positioning (0.9° (SD 1.2°) vs 1.7° (SD 1.1°)), mean tibial positioning (0.3° (SD 0.9°) vs 1.3° (SD 1.0°)), mean posterior tibial slope (-0.3° (SD 1.3°) vs 1.7° (SD 1.1°)), and mean mechanical axis limb alignment (1.0° (SD 1.7°) vs 2.7° (SD 1.9°)) all deviated significantly less from the plan (all p < 0.001); significantly fewer knees required a distal femoral recut (10 (10%) vs 22 (22%), p = 0.033); and deviation from planned polyethylene thickness was significantly less (1.4 mm (SD 1.6) vs 2.7 mm (SD 2.2), p < 0.001). Conclusion RA-TKA is significantly more accurate and precise in planning both component positioning and final polyethylene insert thickness. Future studies should investigate whether this increased accuracy and precision has an impact on clinical outcomes. The greater accuracy and reproducibility of RA-TKA may be important as precise new goals for component positioning are developed and can be further individualized to the patient. Cite this article: Bone Joint J 2021;103-B(6 Supple A):74–80.

The magnetic resonance imaging evaluation of condylar new bone remodeling after Yang’s TMJ arthroscopic surgery

To evaluate the post-operative condylar bone remodeling after the treatment of Yang’s arthroscopic surgery. Consecutive cases from Jan 2017 to May 2018 that received Yang’s arthroscopic surgery were included in this study, the TMJ MRI examinations were performed preoperatively and postoperatively (follow up for 1 year or more), and condylar bone remodeling was estimated. A total of 229 patients (29 male and 200 female) were included in the study, 161 patients had new bone formation, and the average age was 17.5 ± 2.1a. There was no new bone formation in 68 patients with an average age of 24.5 ± 0.7a. The percentage of new bone formation patients in 10–15 years of age was 94.33% and decreases as the age increases. In the position of new bone formation, the posterior slope of condyle was the most (129 joints), the second was the top of condyle (54 joints), the third was around condyle (33 joints), only 25 joints had new bone on the anterior slope of condyle. After TMJ arthroscopic surgery, the condyle has the ability to form new bone, and the younger the age, the stronger the ability of new bone formation. The formation of new bone was most in posterior slope and least in anterior slope of condyle.

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

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

A supplemental screw enhances the biomechanical stability in medial open-wedge high tibial osteotomy

Background The supplemental screw technique was introduced for salvage of lateral hinge fracture in medial open-wedge high tibial osteotomy (owHTO). The efficacy of its use in protection of lateral hinge fracture and corresponding biomechanical behaviors remained unclear. The current study was aimed to clarify if a supplemental screw can provide better protection to lateral hinge in biomechanical perspective. Materials An in vitro biomechanical test was conducted. Tibial sawbones, commercial owHTO plates and a cannulated screw were utilized for preparing the intact, owHTO, and owHTO with cannulated screw insertion specimens. A “staircase” dynamic load protocol was adopted for axial compressive test with increasing load levels to determine structural strength and durability by using a material testing system, while a motion capture system was applied for determining the dynamic changes in varus angle and posterior slope of the tibia plateau with various specimen preparation conditions. Results Type II lateral hinge fracture were the major failure pattern in all specimens prepared with owHTO. The insertion of a supplemental cannulated screw in medial owHTO specimens reinforced structural stability and durability in dynamic cyclic loading tests: the compressive stiffness increased to 58.9–62.2% of an intact specimen, whereas the owHTO specimens provided only 23.7–29.2% of stiffness of an intact specimen. In view of tibial plateau alignment, the insertion of a supplemental screw improved the structural deficiency caused by owHTO, and reduced the posterior slope increase and excessive varus deformity by 81.8% and 83.2%, respectively. Conclusion The current study revealed that supplemental screw insertion is a simple and effective technique to improve the structural stability and durability in medial owHTO.

The Effect of Sagittal Plane Inclination on Posterior Tibial Slope in Medial Open Wedge HTO – Experimental Study With a Square Column Model-

Background: Medial open-wedge high tibial osteotomy (MOWHTO) is an effective and safe treatment method in medial osteoarthritis of knee. However, it may accompany unintended change of posterior tibial slope (PTS). Several factors are known to cause PTS change after MOWHTO. However, there is a lack of research on the sagittal plane osteotomy inclination (SPOI). The purpose of this study was to evaluate that SPOI affected the change in PTS. The hypothesis was that parallel SPOI causes no PTS change after MOWHTO. Methods:A square column model with a 10° posterior slope was produced by two 3D programs and a 3D printer. A series of MOWHTO was performed on a square column model through virtual simulation using two 3D programs and an actual simulation using a 3D printer, a testing machine and a measurement system. The SPOI was divided into 4 types: ① parallel SPOI plus 10° (SPOI: 20°), ② parallel SPOI (SPOI: 10°), ③ perpendicular SPOI (SPOI: 0°), and ④ perpendicular SPOI minus 10° (SPOI: -10°). The correction angle was increased by 5° from 0° to 30°. The change of the posterior slope was measured in sagittal plane.Results: The posterior slope was increased in the parallel SPOI plus 10° (SPOI: 20°). It was maintained in the parallel SPOI (SPOI: 10°) and decreased in the perpendicular SPOI (SPOI: 0°) and perpendicular SPOI minus 10° (SPOI: -10°).Conclusion: SPOI affected the change in PTS. Parallel SPOI causes no PTS change after MOWHTO.