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Background
Derotational osteotomy of the distal femur allows the anatomic treatment of patellofemoral maltracking due to increased femoral antetorsion. However, such rotational osteotomy procedures have a high potential of intended/unintended changes of frontal alignment.
Purpose/Hypothesis
The purpose of this study was to perform derotational ost...
Contexts in source publication
Context 1
... Next, changes of the AMA at cutting because of dero- tation had to be taken into account: The observed AMA at the desired cut on a frontal radiograph measured at a certain femoral antetorsion angle led to an assumed slight increase (positive value) of the AMA because of derotation, described as the Pillar-Crane model. 14 Changes of the AMA are provided in Appendix Table A1. The change of the AMA was subtracted from the corrective angle at the cutting point, which led to the remaining corrective angle at the cutting point ( Figure 4). ...
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Purpose:
The intraoperative version of the femoral component is usually determined by visual appraisal of the stem position relative to the distal femoral condylar axis. However, several studies have suggested that a surgeon's visual assessment of the stem position has a high probability of misinterpretation. We developed a computed tomography (CT...
Citations
... In einem Berechnungsmodell über die 3-dimensionalen Korrekturebenen konnte gezeigt werden, wie schräg eine Sägeebene bei einer Single-cut-Osteotomie sein muss, um bei gegebenem Derotationswinkel eine entsprechende Veränderung der frontalen Achse zu erreichen [5]. ...
A rotational osteotomy requires a complete cut of the bone in order to correct maltorsion. An additional correction of the frontal axis can be achieved via an oblique cut of the bone. The osteotomy with bone to bone contact is fixed with an angle stable plate.
Symptoms such as anterior knee pain, inwardly pointing knee syndrome, lateral patellar subluxation or dislocation, lateral patellar hypercompression syndrome are a common indication for derivational osteotomy if clinically increased femoral internal rotation and radiologically increased femoral antetorsion is detected.
Increased hip external rotation versus internal rotation, increased femoral torsion but no increased internal hip rotation, malcompliance, inability for partial weight bearing, risk of delayed union (nicotine abuse and obesity) as well as patellofemoral arthritis and systematic glucocorticoids, immunosuppressants are (relative) contra-indications.
A lateral or optionally medial approach to the distal femur and exposure of the bone with Eva hooks for the osteotomy is done. The use of patient-specific cutting blocks accurately specify the planned extent of derotation and level of incision. A defined oblique cutting plane of the single-cut osteotomy and derotation will additionally correct/change frontal axis. An additional biplanar osteotomy with an anterior wedge increases intraoperative stability and generates a larger bone contact area for consolidation.
With the use of an extra medullary fixation device partial weight bearing with 15–20 kg with crutches up to 6 weeks is required, but no restriction on knee movement is given.
The literature shows significantly improved patient satisfaction regarding patellofemoral stability and knee function. With the use of patient-specific cutting guides, high accuracy of the osteotomy and 3‑dimensional correction can be achieved, while delayed union rate is up to 10%.
... Previous biomechanical studies and computer simulation models have reported the effect of derotational osteotomies on coronal alignment. Through some of those studies, concerns were expressed regarding an unintended valgization [17,19,26]. In a previous study on patellofemoral instability associated with valgus malalignment and increased femoral antetorsion, however, the authors were able to show that a combined varization and derotation is feasible and accurate using a biplanar supracondylar femoral osteotomy [12]. ...
Purpose The purpose of the study was to report the clinical, functional and radiological outcome following varus osteotomy as a salvage procedure in young to middle-aged patients with patellofemoral arthritis (PFA) and associated valgus malalign-ment. It was hypothesized that a significant improvement in knee function and reduction in pain would be achieved. Moreover, no conversion to patellofemoral joint arthroplasty could be observed.
Material and methods Patients (< 50 years of age) that underwent varus osteotomy between 08/2012 and 01/2020 for the treatment of symptomatic PFA and associated valgus malalignment were consecutively included (minimum follow-up: 24 months). Patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form [IKDC]), Visual Analog Scale [VAS] for pain, Tegner Activity Scale [TAS], and satisfaction with the postoperative results (1-10-scale, 10 = highest satisfaction) and weight-bearing whole-leg anteroposterior radiographs were conducted pre-and postoperatively. The change in PROM and femorotibial angle (FTA) were tested for statistical significance.
Results In total, 12 patients (14 knees) were included (66.7% female; mean age: 33.8 ± SD 6.6 years). In ten cases, lateral opening-wedge distal femoral osteotomies (DFO) were performed, of which three cases included a concomitant femoral derotation. Three medial closing-wedge DFO and one medial closing-wedge high tibial osteotomy were performed. At follow-up (55.3 ± 29.3 months), a significant improvement in knee function (IKDC: 56.4 ± 14.4 to 69.1 ± 11.2, p = 0.015) and reduction in pain (VAS for pain: 3.5 [interquartile range 2.3-5.8] to 0.5 [0-2.0], p = 0.018) were observed. Patients were able to reach their preoperative sporting activity level (TAS: 3.0 [3.0-4.0] to 3.5 [3.0-4.0], p = 0.854) and were highly satisfied with the postoperative result (9.0 [6.5-10]). Additionally, a significant correction of valgus malalignment was observed (5.0° ± 2.9° valgus to 0.7° ± 3.2° varus, p < 0.001). Regarding complications, two re-osteosyntheses were performed due to loss of correction and delayed union. No conversion to patellofemoral arthroplasty occurred.
Conclusion In patients with symptomatic PFA and associated valgus malalignment, varus osteotomy as a salvage procedure achieved a significant improvement in knee function and reduction in pain. No conversion to patellofemoral joint arthroplasty occurred at short-to mid-term follow-up. Level of evidence Retrospective case series, Level IV.
... Recently, excessive femoral anatomical anteversion angle (AFA) has been found in RPD patients (54)(55)(56), and recurrence of patellar dislocation has been found by causing distal femoral internal rotation and incorrect coupling between the patella and the femoral trochlear (54,57,58). To address this risk factor, some studies have suggested performing distal femoral circumcision (DDFO) for these patients (59)(60)(61)(62)(63). However, there is significant controversy regarding the AFA threshold for DDFO. ...
Objectives
Recurrent patellar dislocation (RPD) greatly affects active young individuals, necessitating the identification of risk factors for a better understanding of its cause. Previous research has connected RPD to lower limb alignment (LEA) abnormalities, such as increased femoral anteversion, tibial external rotation, knee valgus, and flexion. This study aims to use EOS technology to detect RPD-related LEA anomalies, enabling three-dimensional assessment under load conditions.
Methods
A total of 100 limbs (50 in the RPD group, 50 in the control group) were retrospectively analyzed. In the RPD group, we included limbs with recurrent patellar dislocation, characterized by dislocations occurs at least two times, while healthy limbs served as the control group. We used EOS technology, including 2D and 3D imaging, to measure and compare the following parameters between the two groups in a standing position: Femoral neck shaft angle (NSA), Mechanical femoral tibial angle (MFTA), Mechanical lateral distal femoral angle (mLDFA), Medial proximal tibial angle (MPTA), Anatomical femoral anteversion (AFA), External tibial torsion (ETT), and Femorotibial rotation (FTR).
Results
The significant differences between the two groups were shown in NSA 3/2D, MFTA 3/2D, mLDFA 3/2D, MPTA 3D, AFA, FTR. No significant difference was shown in MPTA 2D, ETT between the RPD group and the control group. Further binary logistic regression analysis. Further binary logistic regression analysis was conducted on the risk factors affecting RPD mentioned above. and found four risk factors for binary logistic regression analysis: mLDFA (3D), AFA, NSA(3D), and FTR.
Conclusions
EOS imaging identified abnormal LEA parameters, including NSA, MFTA, mLDFA, MPTA, AFA, and FTR, as risk factors for RPD. Children with these risk factors should receive moderate knee joint protection.
... Another opportunity of achieving a higher reliability in (de-rotational) osteotomies could be the application of (patient specific instruments (PSI). If the osteotomy level deviates from the 90°-axis to the mechanical axis, a "single-cut-osteotomy" is performed with undesired side-affects in all dimensions [12,15,22]. ...
Purpose:
The accuracy of intraoperative control of correction commonly is achieved by K-wires or Schanz-screws in combination with goniometer in de-rotational osteotomies. The purpose of this study is to investigate the accuracy of intraoperative torsional control in de-rotational femoral and tibial osteotomies. It is hypothesized, that intraoperative control by Schanz-screws and goniometer in de-rotational osteotomies around the knee is a safe and well predictable method to control the surgical torsional correction intraoperatively.
Methods:
55 consecutive osteotomies around the knee joint were registered, 28 femoral and 27 tibial. The indication for osteotomy was femoral or tibial torsional deformity with the clinical occurrence of patellofemoral maltracking or PFI. Pre- and postoperative torsions were measured according to the method of Waidelich on computed tomography (CT) scan. The scheduled value of torsional correction was defined by the surgeon preoperatively. Intraoperative control of torsional correction was achieved by 5 mm-Schanz-screws and goniometer. The measured values of torsional CT scan were compared to the preoperative defined and intended values and deviation was calculated separately for femoral and tibial osteotomies.
Results:
The surgeon's intraoperative measured mean value of correction in all osteotomies was 15.2° (SD 4.6; range 10-27), whereas the postoperatively measured mean value on CT scan was 15.6 (6.8; 5.0-28.5). Intraoperatively the femoral mean value measured 17.9° (4.9; 10-27) and 12.4° (1.9; 10-15) for the tibia. Postoperatively the mean value for femoral correction was 19.8 (5.5; 9.0-28.5) and 11.3 (5.0; 5.0-26.0) for tibial correction. When considering a deviation of plus or minus 3° to be acceptable femorally 15 osteotomies (53.6%) and tibially 14 osteotomies (51.9%) fell within these limits. Nine femoral cases (32.1.%) were overcorrected, four cases undercorrected (14.3%). Four tibial cases of overcorrection (14.8%) and 9 tibial cases of undercorrection (33.3%) were observed. However, the observed difference between femur and tibia regarding the distribution of cases between the three groups did not reach significance. Moreover, there was no correlation between the extent of correction and the deviation from the intended result.
Conclusion:
The use of Schanz-screws and goniometer in de-rotational osteotomies as an intraoperative control of correction is an inaccurate method. Every surgeon performing derotational osteotomies must consider this and include postoperative torsional measurement in his postoperative algorithm until new tools or devices are available to guarantee a better intraoperative accuracy of torsional correction.
Study design:
Observational study.
Level of evidence:
III.
... Previous reports advocated for restoration of individual patellofemoral tracking with the aim of decreasing the risk of anterior knee pain [14,15]. As the role of excessive FT in TKA has not yet been explored in literature, the main goal of this prospective study was to answer the question whether excessive FT should be corrected in TKA, as it is increasingly performed in patients with patellofemoral instability [4,7,9,11,18,19]. However, no correlation between FT and scores which are specific for the patellofemoral complaints could be found. ...
Purpose
Recent data suggest that individual morphologic factors should be respected to restore preoperative patellofemoral alignment and thus reduce the likelihood of anterior knee pain. The goal of this study was to investigate the effect of excessive femoral torsion (FT) on clinical outcome of TKA.
Methods
Patients who underwent TKA and complete preoperative radiographic evaluation including a long-leg radiograph and CT scan were included. 51 patients showed increased FT of > 20° and were matched for age/sex to 51 controls (FT < 20°). Thirteen patients were lost to follow-up. Thirty-eight matched pairs were compared after a 2 year follow-up clinically (Kujala and patellofemoral score for TKA) and radiographically (FT, frontal leg axis, TT-TG, patellar thickness, patellar tilt, and lateral displacement of patella). Functional alignment of TKA was performed (hybrid-technique). All patellae were denervated but no patella was resurfaced.
Results
There was no significant difference between clinical scores two years after surgery between patients with normal and excessive FT (n.s.). Kujala score was 64.3 ± 16.7 versus 64.8 ± 14.4 (n.s.), and patellofemoral score for TKA was 74.3 ± 21 versus 78.5 ± 20.7 (n.s.) for increased FT group and control group, respectively. There was no correlation between preoperative FT and clinical scores. Other radiographic parameters were similar between both groups. No correlations between clinical outcomes and preoperative/postoperative frontal leg axis or total leg axis correction were found (n.s.).
Conclusion
If the leg axis deformity is corrected to a roughly neutral alignment during cemented TKA, including patellar denervation, then excessive FT was not associated with patellofemoral pain or instability.
Level of evidence
Prospective comparative study, level II.
... Notably, MRI may also be used and may be a more desirable approach in adolescents due to the decreased levels of radiation exposure compared to CT scanning. A variety of measurement techniques have been described using different key axial slices of the femur and tibia [40,[45][46][47]; however, regardless of technique, the normal version of the femur is approximately 22°in children (range 0-65) as compared to roughly 15°(range [10][11][12][13][14][15][16][17][18][19][20] in adults [48][49][50][51]. In children, the average version of the tibia is 20°( range 0-45) [52]. ...
Purpose of Review
The purpose of this review is to highlight the radiographic assessments of utility in the evaluation of a pediatric patient with patellofemoral instability to facilitate a thorough work-up. Understanding of these measures is useful in understanding evolving research in this field, providing accurate patient risk assessment, and appropriately directing surgical decision-making.
Recent Findings
Recent literature has broadened the radiographic characterization of the pediatric patellar instability and its anatomic risk factors. Knee MRI can inform the assessment of skeletal maturity and novel axial alignment measurements may enhance our identification of patients at increased risk of recurrent instability. Additional improvements have been made in the objective measurement and classification of trochlear dysplasia.
Summary
Knee MRI-based skeletal age assessments may obviate the need for hand bone age assessments in growing children with patellofemoral instability. Novel objective measures exist in the evaluation of pediatric patellar instability both in the assessment of axial alignment and trochlear dysplasia. Future work should focus on how these measures can aid in guiding surgical decision-making.
... According to the trend line in Fig. 4A, no relevant frontal axis change is predicted even in case of a > 30° supracondylar femAT correction. Correspondingly, in case of a distal femoral external derotational osteotomy for the treatment of patellofemoral instability [14,15,30], one should not be concerned about further accentuated and unfavorable valgus deformity, even in cases with an additional 5° error. If, however, frontal and rotational alignment is to be addressed simultaneously, the cutting angle of the proximal femoral cut should be tilted in the lateral view [14,17,20] According to Jud et al. [20], 15° femoral derotational/rotational osteotomies with mal-angulations as small as 10° result in a relevant postoperative mechanical leg axis deviation of more than 2°. ...
... Correspondingly, in case of a distal femoral external derotational osteotomy for the treatment of patellofemoral instability [14,15,30], one should not be concerned about further accentuated and unfavorable valgus deformity, even in cases with an additional 5° error. If, however, frontal and rotational alignment is to be addressed simultaneously, the cutting angle of the proximal femoral cut should be tilted in the lateral view [14,17,20] According to Jud et al. [20], 15° femoral derotational/rotational osteotomies with mal-angulations as small as 10° result in a relevant postoperative mechanical leg axis deviation of more than 2°. ...
PurposeThe purpose of this study was to investigate if one level of corrective femoral osteotomy (subtrochanteric or supracondylar) bears an increased risk of unintentional implications on frontal and sagittal plane alignment in a simulated clinical setting.
Methods
Out of 100 cadaveric femora, 23 three-dimensional (3-D) surface models with femoral antetorsion (femAT) deformities (> 22° or < 2°) were investigated, and femAT normalized to 12° with single plane rotational osteotomies, perpendicular to the mechanical axis of the femur. Change of the frontal and sagittal plane alignment was expressed by the mechanical lateral distal femoral angle (mLDFA) and the posterior distal femoral angle (PDFA), respectively. The influence of morphologic factors of the femur [centrum–collum–diaphyseal (CCD) angle and antecurvatum radius (ACR)] were assessed. Furthermore, position changes of the lesser (LT) and greater trochanters (GT) in the frontal and sagittal plane compared to the hip centre were investigated.ResultsMean femoral derotation of the high-antetorsion group (n = 6) was 12.3° (range 10–17°). In the frontal plane, mLDFA changed a mean of 0.1° (− 0.06 to 0.3°) (n.s.) and − 0.3° (− 0.5 to − 0.1) (p = 0.03) after subtrochanteric and supracondylar osteotomy, respectively. In the sagittal plane, PDFA changed a mean of 1° (0.7 to 1.1) (p = 0.03) and 0.3° (0.1 to 0.7) (p = 0.03), respectively. The low-antetorsion group (n = 17) was rotated by a mean of 13.8° (10°–23°). mLDFA changed a mean of − 0.2° (− 0.5° to 0.2°) (p < 0.006) and 0.2° (0–0.5°) (p < 0.001) after subtrochanteric and supracondylar osteotomy, respectively. PDFA changed a mean of 1° (− 2.3 to 1.3) (p < 0.01) and 0.5° (− 1.9 to 0.3) (p < 0.01), respectively. The amount of femAT correction was associated with increased postoperative deviation of the mechanical leg axis (p < 0.01). Using multiple regression analysis, no other morphological factors were found to influence mLDFA or PDFA. Internal rotational osteotomies decreased the ischial-lesser trochanteric space by < 5 mm in both the frontal and sagittal plane (p < 0.001).Conclusions
In case of femAT correction of ≤ 20°, neither subtrochanteric nor supracondylar femoral derotational or rotational osteotomies have a clinically relevant impact on frontal or sagittal leg alignment. A relevant deviation in the sagittal (but not frontal plane) might occur in case of a > 25° subtrochanteric femAT correction.
Level of evidenceIV.
... In fact, the concurrent mild to moderate valgus deformity could be corrected simultaneously by derotational femoral osteotomy without increasing treatment-related morbidity. 18 For patients with severe trochlear dysplasia, a recent meta-analysis found that combined trochleoplasty decreased the redislocation rate at the cost of a higher risk of postoperative range-of-motion limitation. 39 In the present systematic review, no redislocations occurred among the patients who did not undergo trochleoplasty. ...
Background
Studies on the clinical outcomes of derotational femoral osteotomy to treat recurrent patellar dislocation in the presence of increased femoral anteversion are limited.
Purpose
To investigate the role of derotational femoral osteotomy in the treatment of recurrent patellar dislocation in the presence of increased femoral anteversion.
Study Design
Systematic review; Level of evidence, 4.
Methods
A systematic review was performed according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) by searching the Medline, Embase, Web of Science, and Cochrane Library databases through February 10, 2021. Included were studies of skeletally mature patients presenting with recurrent patellar dislocation and exhibiting increased femoral anteversion who subsequently underwent derotational femoral osteotomy. Methodological quality was assessed using the MINORS (Methodological Index for Nonrandomized Studies) score. The basic characteristics of each study were recorded and analyzed: characteristic information, radiological parameters, surgical techniques, patient-reported outcomes, and complications.
Results
A total of 6 studies with 163 patients (170 knees) were included. Sample sizes ranged from 7 to 66 patients, and the patients were predominantly women (range, 79%-100%). The mean age and follow-up ranges were 18 to 28 years and 16 to 44 months, respectively. The mean femoral anteversion decreased significantly from 34° preoperatively to 12° postoperatively. In studies reporting pre- and postoperative outcomes, significant improvements were found in the Lysholm score (from 24.8 to 44.1), Kujala score (from 15.8 to 41.9), International Knee Documentation Committee score (from 11.0 to 28.0), and visual analog scale for pain (from 2.0 to 3.7). All studies reported postoperative complications, giving an overall reported complication rate of 4.7%, but no redislocations occurred during the follow-up period.
Conclusion
For recurrent patellar dislocation in the presence of increased femoral anteversion, combination treatment with derotational femoral osteotomy led to favorable clinical outcomes with a low redislocation rate. However, there was no consensus among researchers on the indications for derotational femoral osteotomy in the treatment of recurrent patellar dislocation.
... Osteotomies can be placed about the intertrochanteric, subtrochanteric, diaphyseal or distal metaphyseal regions and fixed with a plate, an intramedullary nail, external fixator, or a combination thereof [43,104,105]. The literature has described corrective osteotomy in patients with radiographic femoral anteversion >20° to 25° [106][107][108][109] The effect of transverse plane correction on other planes is an important consideration [110,111]. Using computer modeling from CT data of a femur, Nelitz et al. demonstrated that proximal femoral osteotomies created varus alignment and distal osteotomies created valgus alignment [112]. ...
... Osteotomies can be placed about the intertrochanteric, subtrochanteric, diaphyseal, or distal metaphyseal regions and fixed with a plate, an intramedullary nail, external fixator, or a combination thereof [43,104,105]. The literature has described corrective osteotomy in patients with radiographic femoral anteversion >20 • to 25 • [106][107][108][109] The effect of transverse plane correction on other planes is an important consideration [110,111]. Using computer modeling from CT data of a femur, Nelitz et al. demonstrated that proximal femoral osteotomies created varus alignment and distal osteotomies created valgus alignment [112]. ...
Patellofemoral instability (PFI) encompasses symptomatic patellar instability, patella subluxations, and frank dislocations. Previous studies have estimated the incidence of acute patellar dislocation at 43 per 100,000 children younger than age 16 years. The medial patellofemoral ligament (MPFL) complex is a static soft tissue constraint that stabilizes the patellofemoral joint serving as a checkrein to prevent lateral displacement. The causes of PFI are multifactorial and not attributed solely to anatomic features within the knee joint proper. Specific anatomic features to consider include patella alta, increased tibial tubercle–trochlear groove distance, genu valgum, external tibial torsion, femoral anteversion, and ligamentous laxity. The purpose of this paper is to provide a review of the evaluation of PFI in the pediatric and adolescent patient with a specific focus on the contributions of coronal and transverse plane deformities. Moreover, a framework will be provided for the incorporation of bony procedures to address these issues.
... As regards three-dimensional alignment change in a femoral osteotomy, a cadaveric study by Imhoff et al. showed coupled rotational and coronal plane (varus/valgus) alignment changes occurring in corrective femoral osteotomy 14 Several clinical studies have examined the postoperative change in rotational alignment after OWHTO; however, the reported results are somewhat discordant. An increased internal rotation of the distal bony fragment (decreased tibial torsion) was shown in some studies, 13,15 while no significant postoperative change was noted in another study. ...
Purpose
To analyze the change in rotational alignment caused by double level osteotomy (DLO) based on comparative three-dimensional image analysis of pre- and postoperative CT images.
Methods
Pre- and postoperative CT examination of the lower extremities were performed with informed consent for 39 consecutive knees undergoing DLO for varus knee deformity. The DLO procedure consisted of closed wedge distal femoral osteotomy (CWDFO) and open wedge high tibial osteotomy (OWHTO). Among those cases, 20 knees complicated with hinge fracture at the osteotomy site were excluded from the analysis to eliminate a confounding factor affecting the results. Consequently, data obtained from 19 knees were subjected to the study analysis while osteotomies with hinge fractures complications were excluded from the study. In the three-dimensional CT image analysis of axial plane images, femoral torsion (the angle between midline along the femoral neck axis and the tangent of the posterior edges of the medial/lateral femoral condyles) and tibial torsion (the angle between the tangent of the posterior edges of the medial/lateral tibial condyles and the transmalleolar axis) were measured. The torsion angle was measured in each of the femurs and the tibias on both pre- and postoperative CT axial images, and the change induced by the osteotomy was calculated and statistically(using Wilcoxon signed-rank test) compared.
Results
The mean pre- and postoperative femoral torsion (anteversion) angles were 29.3° and 31.4° with a significant postoperative increase in internal rotation of the bony segment distal to the osteotomy(P = 0.002). On the tibial side, the mean pre- and postoperative torsion angles were 26.5° and 25.7°, indicating no significant postoperative change(P = 0.199)（NS）.
Conclusions
This study showed that the DLO procedure (combining CWDFO and OWHTO) increased torsion (anteversion) of the femur by 2.1° on average while inducing no significant rotational change on the tibial side.
