Determining the Ratio of Wedge Height to Degree of Correction for Anterior Tibial Closing Wedge Osteotomies for Excessive Posterior Tibial Slope

2021 ◽  
pp. 036354652110441
Author(s):  
Courtney A. Quinn ◽  
Mark D. Miller ◽  
Robert D. Turk ◽  
Daniel C. Lewis ◽  
Christopher M. Gaskin ◽  
...  

Background: Anterior closing wedge osteotomy of the proximal tibia may be considered in revision anterior cruciate ligament (ACL) reconstruction surgery for patients with excessive posterior tibial slope (PTS). Purpose: (1) To determine the ratio of wedge thickness to degrees of correction for supratubercle (ST) versus transtubercle (TT) osteotomies for anterior closing wedge osteotomies and (2) to evaluate the accuracy of ST and TT osteotomies in achieving slope correction. Study Design: Controlled laboratory study. Methods: The computed tomography (CT) scans of 38 knees in 37 patients undergoing revision ACL reconstruction were used to simulate both ST and TT osteotomies. A 10° wedge was simulated in all CT models. The height of the wedge along the anterior tibia was recorded for each of the 2 techniques. The ratio of wedge height to achieved degree of correction was calculated. ST and TT osteotomies were performed on 3-dimensional (3D)–printed tibias of the 12 patients from the study group with the greatest PTS, after the desired degree of correction was determined. Pre- and postosteotomy slopes were measured for each tibia, and the actual change in slope was compared with the intended slope correction. Results: According to CT measurements, the ratio of wedge height to degree of correction was 0.99 ± 0.07 mm/deg for the ST osteotomy and 0.83 ± 0.06 mm/deg for the TT osteotomy ( P < .001). When these ratios were used to perform simulated osteotomies on the twelve 3D-printed tibias, the mean slope correction was within 1° to 2° of the intended slope correction, regardless of osteotomy location (ST or TT) or whether slope was measured on the medial or lateral plateau. The ST technique tended to undercorrect and the TT technique tended to overcorrect. Conclusion: When anterior tibial closing wedge osteotomies were removed to correct excessive PTS, removing a wedge with a ratio of 1 mm of wedge height for every 1° of intended correction for an ST technique and a ratio of 0.8 mm to 1° for a TT technique resulted in overall average slope correction within 1° to 2° of the target. Clinical Relevance: The calculated ratios will allow clinicians to more accurately correct PTS when performing anterior closing wedge tibial osteotomy.

2020 ◽  
Vol 8 (5_suppl4) ◽  
pp. 2325967120S0028
Author(s):  
Jörg Dickschas

Aims and Objectives: In recent publications on acl-ruptures and especially on failure of acl reconstruction there comes a strong focus on posterior tibial slope (PTS). ACL reconstructions with a PTS of >12° have an 8 times higher risk of recurrent instability and reconstruction failure. But many questions stay unclear so far-When do we have to correct the tibial slope? How do we correct it? What about simultaneous frontal axis deviations? In this publication a new algorhythm is presented. Materials and Methods: The following aspects have to be evaluated Is the PTS the only dimension of the deformity or do we have to correct the frontal axis simultaneuosly? Performing a anterior closed wedge extension osteotomy: when do we go distal the tuberosity and when do we perform a tuberosity osteotomy and use it as “bio plating”? Osteosynthesis only screws or always plate? Are there indications for a contineous correction, f.e. with a hexapod? Whats the role of preoperative range of motion of the knee (especially extension)? Always tunnel filling in the same surgery? What about PCL insufficiency and low PTS? Results: An algorhythm is presented giving a treatment path for the different questions mentioned. The procedures are shown step by step in clinical examples and surgery documentation for every pathway. Conclusion: Posterior tibial slope plays an critical role in ACl recontruction. In primary ACl tear a slope correction is probably not indicated. In ACL reconstruction failure a analysis of the PTS needs to be done and correction needs to be discussed. Simultaneuous varus deormities need to be corrected by openwedge valgisation - extension high tibial osteotomy (HTO), while as isolated PTS elevation is subject to an anterior closed wedge extension HTO. Preoperative range of motion needs to be respected not to create hyperextension. Osteosynthesis can be perormed with only screws using the tibial tubercle as “bio-plating”. In cases of former bone-tendeon-bone (BTB) ACL reconstruction a tibial tubercle osteotomy should be avoided and a infratuberositeal osteotomy should be performed and stabilized with plate osteosynthesis. In severe postraumatic cases contineous correction of the slope with fixateur externe, f.e. hexapodes, needs to be performed.


2021 ◽  
Vol 10 (3) ◽  
pp. e897-e902
Author(s):  
CPT Christian A. Cruz ◽  
CPT Mitchell C. Harris ◽  
CPT Jeffery L. Wake ◽  
CPT Gregory E. Lause ◽  
Brian J. Mannino ◽  
...  

2019 ◽  
Vol 47 (2) ◽  
pp. 285-295 ◽  
Author(s):  
Alberto Grassi ◽  
Luca Macchiarola ◽  
Francisco Urrizola Barrientos ◽  
Juan Pablo Zicaro ◽  
Matias Costa Paz ◽  
...  

Background: Tibiofemoral anatomic parameters, such as tibial slope, femoral condyle shape, and anterior tibial subluxation, have been suggested to increase the risk of anterior cruciate ligament (ACL) reconstruction failure. However, such features have never been assessed among patients experiencing multiple failures of ACL reconstruction. Purpose: To compare the knee anatomic features of patients experiencing a single failure of ACL reconstruction with those experiencing multiple failures or with intact ACL reconstruction. Study: Case-control study; Level of evidence, 3. Methods: Twenty-six patients who experienced failure of revision ACL reconstruction were included in the multiple-failure group. These patients were matched to a group of 25 patients with failure of primary ACL reconstruction and to a control group of 40 patients who underwent primary ACL reconstruction with no failure at a minimum follow-up of 24 months. On magnetic resonance imaging (MRI), the following parameters were evaluated: ratio between the height and depth of the lateral and medial femoral condyles, the lateral and medial tibial plateau slopes, and anterior subluxation of the lateral and medial tibial plateaus with respect to the femoral condyle. The presence of a meniscal lesion during each procedure was evaluated as well. Anatomic, demographic, and surgical characteristics were compared among the 3 groups. Results: The patients in the multiple-failure group had significantly higher values of lateral tibial plateau slope ( P < .001), medial tibial plateau slope ( P < .001), lateral tibial plateau subluxation ( P < .001), medial tibial plateau subluxation ( P < .001), and lateral femoral condyle height/depth ratio ( P = .038) as compared with the control group and the failed ACL reconstruction group. Moreover, a significant direct correlation was found between posterior tibial slope and anterior tibial subluxation for the lateral ( r = 0.325, P = .017) and medial ( r = 0.421, P < .001) compartments. An increased anterior tibial subluxation of 2 to 3 mm was present in patients with a meniscal defect at the time of the MRI as compared with patients who had an intact meniscus for both the lateral and the medial compartments. Conclusion: A steep posterior tibial slope and an increased depth of the lateral femoral condyle represent a common finding among patients who experience multiple ACL failures. Moreover, higher values of anterior subluxation were found among patients with repeated failure and those with a medial or lateral meniscal defect.


2021 ◽  
Vol 1 (5) ◽  
pp. 263502542110326
Author(s):  
Richard Danilkowicz ◽  
Kier Maddox Blevins ◽  
Brian Lau ◽  
Annunziato Amendola

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.


2018 ◽  
Vol 32 (08) ◽  
pp. 758-763 ◽  
Author(s):  
Jiangfeng Lu ◽  
Shiyu Tang ◽  
Yanru Wang ◽  
Yao Li ◽  
Chang Liu ◽  
...  

AbstractThis article compares the long-term outcomes of closing-wedge osteotomy (CWO) and opening-wedge osteotomy (OWO) in the treatment of unicompartmental medial osteoarthritis with varus deformity. This study included 79 patients who underwent high tibial osteotomy (HTO) between 2002 and 2008. Pre- and postoperative radiography and computed tomography were used to evaluate the posterior tibial slope, the patellar height, the tibiofemoral angle, and the lateral and medial tibiofemoral joint space. Pre- and postoperative severity of arthritis was assessed with the Kellgren–Lawrence grading system. Pre- and postoperative American Knee Society (AKS) score and Lysholm Knee Score (LKS) were determined to evaluate functional outcomes. The duration of follow-up was 86.1 ± 6.2 months. Postoperatively, at the most recent follow-up, there was a slight increase in the size of the medial tibiofemoral joint space after CWO and OWO, which reflected a decrease in stress on the medial compartment and manifested as a significant improvement in the AKS knee and function scores and the LKS. OWO increased the posterior tibial slope as compared with the preoperative value, while CWO reduced the posterior tibial slope. CWO and OWO for HTO resulted in similar functional outcomes. OWO was associated with patella infera and more severe patellofemoral arthritis, while CWO was associated with a greater severity of lateral tibiofemoral arthritis.


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