Derotational Femoral Osteotomy for Femoral Torsion Abnormalities

Editorial Commentary: Surgical Treatment Algorithm for Patellofemoral Recurrent Instability

The aim was to assess the influence of femoral derotational osteotomy on patella tilt (PT), axial patella engagement (AEI) and tibial tuberosity trochlear groove distance (TTTG). Derotational femoral osteotomy was performed on ten lower limbs of body donors embalmed with alcohol-glycerine. Femoral torsion, tibial torsion, knee torsion, PT, AEI and TTTG were evaluated on axial CT slices for an absolute femoral torsion of 15°, 20°, 25°, 30°, 35° and 40°. A linear mixed model analysis was used to estimate the effect of femoral torsion on PT, AEI, TTTG and knee torsion adjusted for correlation due to repeated observations. Estimates with 95% confidence intervals were used to represent the mean change in the dependent variables for one unit of change (degree, mm or AEI) in the predictor variable. A significant correlation was observed between femoral torsion and AEI (p < 0.001), PT (p < 0.001) and TTTG distance (p = 0.002). In cases of increased internal femoral torsion, a significant decreased AEI (estimate -0.003, 95% CI -0.003 to -0.002), an increased PT (estimate 0.3, 95% CI 0.2-0.4) and an increased TTTG distance (estimate 0.1, 95% CI 0.1-0.2) were observed. No correlation was seen between change in femoral torsion and knee torsion (n.s.). Derotational femoral osteotomy has a significant impact on patella tilt and axial patella engagement. Moreover, TTTG distance is slightly changed by a derotational femoral osteotomy, which has to be taken into account preoperatively when considering surgical procedures. Level V.

The purpose of this study was toinvestigate whether double-level (femur + tibia) derotational osteotomy is superior to single-level femoral derotational osteotomy for recurrent patellar dislocation with severe femoral and tibial rotational deformities (femoral anteversion >30° and external tibial torsion >30°). Between January 2015 and June 2020, a total of 115 knees with recurrent patellar dislocation treated with combined medial patellofemoral ligament reconstruction (MPFL-R) and derotational osteotomies were evaluated after a minimum follow-up of 2 years. Among these cases, 15 knees that underwent double-level derotational osteotomy were included in the double-level group, which was propensity-matched in a 1:2 ratio to a single-level group of patients who underwent single-level femoral derotational osteotomy (30 knees). The clinical and radiological outcomes were evaluated and compared between the groups. Furthermore, the foot progression angle was measured preoperatively and 2 years after surgery. The patient-specific variables did not differ significantly between the double-and the single-level groups after propensity score matching. The postoperative mean foot progression angle was significantly lower in the double-level groupthan in the single-level group (9° ± 8° vs. 15° ± 11°; p = 0.014); however, there were no statistically significant differences between the groups in terms of any other clinical and radiological assessments. For patients with severe femoral and tibial torsional deformities (femoral anteversion >30° and external tibial torsion >30°), the double-level derotational osteotomy is superior to single-level osteotomy in maintaining normal foot progression angle, but it does not show an advantage in terms of patient-reported outcomes, radiological resultsand redislocation rate at minimum 2 years of follow-up. Furthermore, concomitant excessive external tibial torsion (>30°) did not have an adverse effect on clinical outcomes in patients who underwent derotational distal femoral osteotomy with MPFL-R due to excessive femoral anteversion. Level III.

Investigate intra- and post-operative complications and revisions following distal femoral and/or high tibial derotational osteotomies to correct rotational malalignments of the lower limb in patients with anterior knee pain (AKP) and/or patellofemoral instability (PFI). A literature search was conducted on PubMed, EMBASE and Web of Science (until 30 September 2023), including studies reporting complications, reinterventions and revisions following knee derotational osteotomies. Incidence rates were collected for each level of derotational osteotomy (distal femur, high tibia or double-level). A meta-analysis using the Freeman-Tukey double arcsine transformation was conducted to estimate the pooled proportions with their 95% confidence intervals (CIs). Twenty-one studies involving 564 osteotomies (n = 484) were included, with a mean follow-up of 45.6 ± 15.7 months. The overall complication proportion was 7.5% (95% CI: 3.9-11.8%). Postoperative residual AKP was seen in a pooled proportion of 7.6% (95% CI: 0.7-18.8%), and persistent PFI was not common (0.1%; 95% CI: 0.0-1.7%). Intraoperative complications occurred in a pooled proportion of 3.8% (95% CI: 2.4-6.0%), with peroneal nerve injury being the most common (1.3%) after derotational high tibial osteotomy. Reintervention was needed in a pooled proportion of 13.0% (95% CI: 2.9-27.2%), primarily for hardware removal (n = 158; 28.3%). There was a pooled proportion of knees requiring revision procedures of 12.3% (95% CI: 2.6-26.1%). Distal femur and high tibial derotational osteotomies exhibit a considerable incidence of intra- and post-operative complications. Peroneal nerve injury, although infrequent, is a significant complication, underscoring the importance of implementing intraoperative preventive measures during derotational high tibial osteotomy.

Excessive femoral internal torsion is an important risk factor for patellar dislocation. The aim of the present study was to estimate the effect of derotational osteotomy of the femur on the tibial tubercle trochlear groove (TTTG) distance or patellar tilt angle (PTA) and to report our clinical outcomes of recurrent patellar dislocation after femoral derotation osteotomy. A retrospective analysis of 16 patients (17 knees) with recurrent patellar dislocation treated by femoral derotation osteotomy in our department from January 2016 to February 2019 was carried out. The procedure was performed with supracondylar femoral derotation. A few procedures were combined with soft tissue procedures. Knee function was evaluated by using the International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score, visual analog scale (VAS) score and patient satisfaction. Additionally, CT was used to assess the influence of femoral derotational osteotomy on TTTG distance and PTA. The average femoral antetorsion angle before surgery was 33° (SD ± 5°), and the intraoperative correction angle was 23° (SD ± 4°). A total of 17 femoral derotation osteotomies in 16 patients with patellar instability [11 females, 5 males, aged 20.8 (range 15-41) years] were included in the study. No dislocation occurred within 26.5months after follow-up (range 12-49months). The IKDC score, Kujala score, Lysholm score and VAS score significantly improved. The preoperative TTTG distance was 15.63mm (SD ± 2.07mm), and it was 14.69mm (SD ± 1.78mm) at the follow-up. The PTA decreased from 26.35° (SD ± 6.86°) to 11.65° (SD ± 2.85°). The powers of TTTG and PTA measurements are 0.78 and 1.00, respectively and all of these differences were statistically significant. Derotational osteotomy of the femur for the treatment of recurrent patellar dislocation can achieve good clinical results, including improved TTTG distance and PTA and improved knee function.

The aim of this study was to evaluate the clinical effect of derotational femoral osteotomy combined with medial patellofemoral ligament reconstruction for patellar dislocation and the effect of the distribution of femoral torsion at different segments on postoperative function. Forty-two patients with patellar dislocation who underwent derotational femoral osteotomy from 2017 to 2021 were retrospectively analysed. All patients received computed tomography scans from the hip to the knee to evaluate correction of the femoral anteversion (FA) angle, patellar tilt angle (PTA) and congruence angle (CA) after derotational femoral osteotomy. Subjective scores, such as the Kujala, Lysholm, International Knee Documentation Committee (IKDC), Tegner and visual analog scale (VAS) scores, were used to evaluate knee function before and after the operation. Patients with supracondylar torsion > distal torsion were categorized into the supracondylar torsion group and patients with distal torsion > supracondylar torsion were categorized into the distal torsion group. Subgroup analyses were performed. No presentation of redislocation occurred in these patients at the minimum 2-year follow-up visit. The mean preoperative FA angle in the supracondylar torsion group was 30.2° ± 4.2°, and the mean postoperative FA angle was 14.5° ± 2.5° (p < 0.001). The mean preoperative FA angle was 26.7° ± 1.4° and the mean postoperative FA angle was 14.1° ± 1.4° in the distal torsion group. In addition, postoperative PTA and CA were significantly corrected in both groups (p < 0.001). The postoperative Kujala, Lysholm, IKDC, Tegner and VAS scores were significantly improved in both groups (p < 0.001). Subgroup analyses showed a higher preoperative FA in the supracondylar torsion group and a higher occurrence of high-grade trochlear dysplasia in the distal torsion group. However, there was no significant difference in their postoperative clinical outcomes. Through a minimum of 2-year follow-up visits of patients with patellar dislocation and increased FA, it was found that derotational femoral osteotomy could significantly reduce FA and improve subjective knee function. The pattern of torsion distribution did not significantly affect the clinical outcomes of derotational femoral osteotomy. These findings readvised orthopaedic surgeons that derotational femoral osteotomy remains the preferred procedure for correcting rotational malalignment, but that they should be more cautious about its indications. Level IV.

BackgroundIncreased torsional deformity of femur is one of the most important factors in recurrent patellofemoral instability. And distal femoral derotational osteotomy is an effective treatment option in patients with increased femoral torsional deformity. However, groin pain is a rare complication after femoral derotational osteotomy.Case presentationThe patient was a 23‐year‐old female suffering from anterior knee pain and patellar instability in her left leg. Continuous CT scans of the hip, knee, and ankle were performed and the femoral anteversion was 44.99°. Considering the significant enlargement of the femoral internal torsion which may contribute most for dislocation of patella, we did a derotational osteotomy of distal femur. The anterior knee pain and patellar instability were resolved after surgery. The femoral internal torsion angle was corrected to 21.47°. But she developed left hip pain in the groin area which she had never encountered before 1 year after the surgery. We believed that the hip pain was closely related to the surgery. And the imaging and follow‐up partly confirmed this.ConclusionsThe situation of the hip joint should be carefully evaluated before doing derotational osteotomy in recurrent patellofemoral instability and patient should be informed that derotational osteotomy may cause hip pain. Clinical studies are needed to further clarify the impact of derotational osteotomy on the hip.

Pathological femoral anteversion (FAV) or femoral maltorsion is often overlooked as a cause of anterior knee pain (AKP). Therefore, it should be routinely evaluated during physical examination of the patient with AKP. FAV is a problem because it changes the direction of the quadriceps and thereby the force acting on the patellofemoral joint. The Murphy CT method comes closest to showing the anatomical reality when FAV is evaluated. The treatment of choice in a patient with AKP with symptomatic excessive FAV is the femoral derotational osteotomy. Before doing a derotational osteotomy, the hip joint should be evaluated to avoid hip pain. Currently, no scientific evidence supports the cutoff point at which derotational femoral osteotomy should be the treatment of choice in young patients with AKP with symptomatic pathological FAV. Furthermore, no evidence exists regarding the level at which the osteotomy must be done.

Axial alignment of the femur and tibia is often misdiagnosed in patients with patellofemoral stability problems. Femoral torsion is critical for patellofemoral biomechanics, so it must be evaluated in every patient before the plan of surgery is decided. This case describes a femoral derotational osteotomy due to excessive internal torsion of the femur fixed with a retrograde femoral nail. This type of fixation provides a biomechanical advantage compared to plates. At the two-year follow-up, the patient achieved excellent results, reaching a functional score of 91 points on the Lysholm scale. Derotational femoral osteotomy should be considered in patellofemoral pathology, and a retrograde femoral nail is a valid fixation method for this surgery.

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.

Excessive femoral anteversion is a developmental condition that can become symptomatic into adolescence and manifest as anterior knee pain, tripping, and or problems with sports. Femoral derotational osteotomy about an antegrade intramedullary nail (IMN) is an accepted option to treat this condition. This is the first report of the clinical and functional outcomes of treatment of excessive anteversion with femoral derotational osteotomy stabilized with an IMN. We prospectively enrolled 28 consecutive patients between 2013 and 2014 who underwent derotational osteotomy. Physical examination measures were used to calculate the amount of angular correction with focus on internal and external rotation of the hip, as well as the trochanteric prominence angle test of femoral anteversion. The International Knee Documentation Committee-9, Marx, and Tegner activity scales were 3 patient-reported outcomes recorded. After femoral derotation osteotomy over an IMN, femoral anteversion, as measured by the trochanteric prominence angle, improved an average of 29 degrees (P<0.0001). At 1-year minimum follow-up, 22 of 28 subjects (78.5%) demonstrated a mean significant improvement of 13 points for International Knee Documentation Committee-9 (SD=15.4, P=0.0007), which surpassed the level of minimal clinically important change. Furthermore, the Tegner inventory scores for the cohort improved by an average of 1.9 activity levels (SD=2.4, P=0.0012). For adolescents with symptomatic excessive femoral anteversion, derotational osteotomy over an IMN offers a reliable surgical option that provides predictable deformity correction and significant improvements in both function and pain scales. Level II-prospective, consecutive, nonrandomized, internally controlled cohort study.

Background:Version abnormalities of the femur can cause pain and hip joint damage due to impingement or instability. A retrospective clinical review was conducted on patients undergoing a subtrochanteric derotation osteotomy for either excessive anteversion or retroversion of the femur.Methods:A total of 55 derotation osteotomies were performed in 43 patients: 36 females and 7 males. The average age was 29 years (range, 14 to 59 years). The osteotomies were performed closed with an intramedullary saw. Fixation was performed with a variety of intramedullary nails. Twenty-nine percent of patients had a retroversion deformity (average, −9° of retroversion; range, +2° to −23°) and 71% had excessive anteversion of the femur (average, +37° of anteversion; range, +22° to +53°). The etiology was posttraumatic in 5 patients (12%), diplegic cerebral palsy in 2 patients (5%), Prader-Willi syndrome in 1 patient (2%), and idiopathic in 35 patients (81%). Forty-nine percent underwent concomitant surgery with the index femoral derotation osteotomy, including hip arthroscopy in 40%, tibial derotation osteotomy in 13%, and a periacetabular osteotomy in 5%. Tibial osteotomies were performed to correct a compensatory excessive external tibial torsion that would be exacerbated in the correction of excessive femoral anteversion.Results:No patient was lost to follow-up. Failures occurred in three hips in three patients (5%): two hip arthroplasties and one nonunion that healed after rerodding. There was one late infection treated successfully with implant removal and antibiotics with an excellent final clinical outcome. At an average follow-up of 6.5 years (range, 2 to 19.7 years), the modified Harris Hip Score improved by 29 points in the remaining 52 cases (P < 0.001, Wilcoxon signed-rank test). The results were rated as excellent in 75%, good in 23%, and fair in 2%. Subsequent surgery was required in 78% of hips, 91% of which were implant removals.Conclusions:A closed, subtrochanteric derotation osteotomy of the femur is a safe and effective procedure to treat either femoral retroversion or excessive anteversion. Excellent or good results were obtained in 93%, despite the need for subsequent implant removal in more than two-thirds of the patients.

The 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. 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. Mean 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 < 5mm in both the frontal and sagittal plane (p < 0.001). 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. IV.

Biomechanical changes associated with femoral derotational osteotomy

Controversy exists regarding the origin of femoral torsion, and specific treatment rules regarding the optimal position of femoral osteotomy in patients with recurrent patellar subluxation and excessive femoral torsion are scarce. To establish a novel classification system for such patients, and to compare clinical and radiological outcomes after distal derotational femoral osteotomy (DDFO) between femoral torsion at proximal (neck and shaft) and distal levels. Between January 2014 and June 2019, patients who underwent DDFO were retrospectively reviewed. The segmental torsion analysis was performed to establish a novel classification system, and classify included patients into two groups: 35 patients in proximal torsion group and 38 patients in distal torsion group. These patients were followed-up for at least 3years. Clinical evaluations included functional outcomes, physical examinations, quality of life, activity level, satisfaction, and complications. Radiological outcomes included patellofemoral osteoarthritis, congruence, and alignment. Type I was defined as the proximal torsion. Type II was defined as the distal torsion. Proximal torsion group had lower postoperative femoral torsion (12.6 ± 2.6° vs. 14.8 ± 3.6°; P = .004) and higher surgical correction angle (21.6 ± 5.0° vs. 19.1 ± 3.0°; P = .009). All clinical and radiological outcomes improved significantly in both groups, but proximal torsion group had significantly higher quality of life (EQ-5D-5L: 0.96 ± 0.06 vs. 0.91 ± 0.07; P = .003. 92.0 ± 6.0 vs. 88.7 ± 5.8; P = .021) and Tegner activity score (5.2 ± 1.5 vs. 4.5 ± 1.4; P = .040), and fewer patellofemoral osteoarthritis (8.6% vs. 26.3%; P = .048). Two patients in the distal torsion group had subjective patellar instability. The percentage of patients with anterior knee pain was higher in the distal torsion group. A novel classification system for patients with recurrent patellar subluxation and excessive femoral torsion based on segmental femoral torsion analysis was established. DDFO was more appropriate for patients with proximal torsion, yielding higher surgical correction angle, and better clinical and radiological outcomes. Cohort study; Level of evidence, 3.