Aims

Avascular femoral head necrosis in the context of gymnastics is a rare but serious complication, appearing similar to Perthes’ disease but occurring later during adolescence. Based on 3D CT animations, we propose repetitive impact between the main supplying vessels on the posterolateral femoral neck and the posterior acetabular wall in hyperextension and external rotation as a possible cause of direct vascular damage, and subsequent femoral head necrosis in three adolescent female gymnasts we are reporting on.

Femoral head necrosis in the context of high impact gymnastics of young adolescents is rare but seems a more serious complication compared to a Perthes like necrosis.

Between 2017 and 2019, three young females aged from12 to 14 years were referred due incapacitating hip pain and severe collapsing femoral head necrosis. The indication of hip preserving surgery was based on the extent of the necrosis, presence of a vital lateral pillar and joint subluxation.

In one of our 3 cases total head involvement made THR necessary, which was performed elsewhere. In the remaining 2 cases, head reduction osteotomy plus periacetabular osteotomy led to a good and a fair result.

Repetitive impact between the main supplying vessels on the posterolateral femoral neck and the posterior acetabular wall in hyperextension/ external rotation could be the cause of severe femoral head necrosis in three adolescent female gymnasts we are reporting on. Supra-selective angiography or sonography may be helpful to improve indication. Targeted adaptation of training methods should be discussed. Due to the severe vascular insult, results have to be considered moderate.

Introduction: It has been proposed that rotational gait abnormalities in the normal child are usually reflections of the anatomic deformity. A decreased acetabular and femoral anteversion have been recognized as a predisposing factor for osteoarthritis of the hip and the McKibbin instability index was introduced to quantify this relationship. Additionally, an increased femoral anteversion has been associated with osteoarthritis of the knee. However, it is well known that compensatory factors influence the dynamic rotational profile during gait. We compared rotational computed tomography data with gait analysis to evaluate their correlation and to elucidate the influence of compensatory mechanisms.

Materials and Methods: In a prospective study conducted between 2001 and 2005 patients presenting with rotational malalignment were sent for 3D gait analysis. Main exclusion criterion was any kind of neurological affection. Patients in whom surgery was considered were referred to rotational computed tomography. The rotational alignment of the pelvis, hip and knee at different times during the gait cycle as evaluated in the 3D gait analysis was compared to the angular values derived from the rotational computed tomography for the femur and tibia and statistically analyzed and correlated.

Results: There were 12 female and 16 male patients with a mean age of 16 (± 9.7) years at the time of gait analysis. After a first evaluation of data 8 limb segments were excluded to increase the quality of data. The mean anteversion of the femur was 29 degrees (2 degrees of retrotorsion to 56 degrees of anteversion) and the mean tibial torsion was 31 degrees (1 to 66 degrees of external torsion). The calculation of the Pearson correlation showed that an increase of femoral anteversion resulted in an increase of pelvic range of motion. An increase of femoral anteversion resulted in an increase of the internal rotation of the hip. Highly significant correlations were found between the rotational–CT values for the tibia and the all parameters describing rotation of the knee. The determination coefficient was high for tibial torsion versus knee rotation (R2 = 0.64), but showed a low value for femoral anteversion versus hip rotation (R2 = 0.2).

Conclusion: The rotation of the hip as found in the gait analysis showed only weak correlation with rotational CT data. This is not surprising as the hips segment offers many possibilities for compensation. The torsion of the tibia was found to correlate very strongly with the gait analysis. The McKibbin index seems questionable as a prognostic factor for the individual patient in the light of a multitude of dynamic compensatory influences. Effort should be made to integrate the static instability index with dynamic gait analysis data.

Background: Congenital absence of the cruciate ligaments is a commonly associated pathology of the knee joint in congenital longitudinal deformities. We performed a radiological analysis and investigated gait patterns in patients with congenital absence of one or both cruciate ligaments.

Patients and Methods: Thirty-four knee joints in thirty-one patients with congenital longitudinal deficiency of the lower limb were evaluated. The cruciate ligaments and associated abnormalities of the bony configuration were evaluated on magnetic resonance imaging and tunnel view radiographs. A radiological classification is proposed. Gait analysis was employed to determine kinematic, kinetic and electromyographic data in 24 of these patients and the results were compared to an age-matched control group.

Results: We differentiated 3 main types of absence of the cruciate ligaments with typical associated changes in the femoral intercondylar notch (FIN) and the tibial eminence (TE). In type I (n=19) partial closure of the FIN and hypoplasia of the TE was observed in hypoplasia or absence of the ACL, in type II (n=7) these findings were aggravated by additional underlying hypoplasia of the PCL and in type III (n=8) absence of the FIN and a flat TE was observed in aplasia of both cruciate ligaments. The main findings in gait analysis were significantly increased flexion moment of the hip, increased flexion of the knee in midstance phase and reduced ankle power in comparison to the control group.

Conclusion: The knee joint with aplastic cruciate ligaments shows typical radiological changes, thus, one will be able to distinguish between aplasia of the ACL only or both cruciate ligaments by observing plain tunnel view radiographs. Our obtained data of the gait analysis revealed specific gait patterns as adaption to underlying aplasia of the cruciate ligaments.

Introduction: Cases of developmental dislocation of the hip occur after walking age because of late or missed diagnosis and failed conservative or operative treatment. Up to now there is no consensus on the treatment of DDH after walking age. The purpose of this retrospective study was to evaluate the results of operative treatment in DDH after walking age in our patient population and to describe the treatment strategies and operative techniques used.

Material and Methods: Forty-two patients presenting 54 cases of DDH after walking age were operated on in our clinic between 1985 and 1997. There were 34 female and 8 male patients, with an average age at the time of operation of 47 months (range: 14 – 151 months). The parameters studied were the type of DDH according to Ts, the preoperative AC- angle, the postoperative AC- and CE- angles as well as the radiological outcome using the Severin classification.

Results: Based on the Ts classification we found 18 cases of type II, 22 cases of type III and 14 cases of type IV dislocations. Each hip had an average of 1.4 operations. The average preoperative AC- angle was 38.2 degrees (range: 22–50) whereas the average AC- angle in the last radiographic follow up was 22.2 degrees (range:5–10). The statistical analysis showed that the AC angle at the last follow up was significantly (p< 0,001) smaller than in the preoperative radiographs. The classification according to Severin showed class I in 28 cases, class II in 15 cases, class III in 8 cases and class V in 3 cases.

Conclusion: Although our study presents the results after a mid-term follow up the radiological results favor our clinical experience that a single stage combined procedure consisting of open reduction, pelvic osteotomy as well as a corrective osteotomy within the proximal femur with subsequent shortening should be recommended.

Introduction: The knee joint in congenital longitudinal deformities of the lower extremity shows a large variety of pathological findings. Valgus deformity is found in most cases and is described as being juxta- articular. To describe the true anatomic pathology we performed a radiographic analysis of the knee joint in congenital longitudinal deformities.

Patients and Method: Between 1985 and 2001 we treated 102 patients presenting with congenital longitudinal deformities. Inclusion criteria for this study were diagnoses of fibular hemimelia (FBH) and/or congenital femoral deficiency (CFD), an age between 5 and 16 years, unilateral affection and availability of long standing X-rays, whereas bilateral affection or previous operations on the lower extremities were defined as exclusion criteria. Twenty-four parameters were defined on the femur and tibia respectively and a nomenclature was created. The mean values including standard deviation were calculated and we statistically compared the parameters of the affected to those of the non-affected knee. Furthermore, MRI scans of the knee joint of 20 of these patients were evaluated.

Results: Thirty- nine patients (19 female, 20 male) met the inclusion criteria. The average age at the time of evaluation was 8.87 years (3.1 SD). A combined deficiency of femur and tibia was found in 35 patients. The predominant diagnosis was CFD in 13, fibular hemime-lia in 13 and fibular aplasia in 9 cases. The anatomic lateral distal femoral angle (ALDFA) measured 75.4° (2.5 SD) on the affected, and 81.6° (1.6 SD) on the non-affected knee. The lateral distal femoral metaphyseal angle of the affected side and of the non-affected side showed no significant difference. The distal lateral femoral epiphyseal width (DLFEW) was decreased in the affected limb compared to the non affected limb, whereas the distal medial femoral epiphyseal width (DMFEW) of the affected and non-affected side showed only a minor difference. In the tibia we found no significant difference between the variables for the medial proximal tibial angle (MPTA) and for the medial proximal tibial metaphyseal angle (MPTMA) of the affected and the non-affected limb. A significant difference was found between the proximal lateral tibial epiphyseal width of the affected and the non-affected side. Analysis of the MRI scans revealed aplasia of the anterior cruciate ligament in 18 cases and aplasia of the posterior cruciate ligament in 8 of the 20 cases. The defect of ossification of the lateral tibial epiphysis as seen in plain X-rays is visible in the MRI scans as cartilage anlage. (Only the most important findings are summarized)

Conclusions: In our patient population only four patients had FBH or CFD but 35 cases presented combined defects; we assume that the femur is affected to some extent in almost all cases of FBH. The hypoplasia was only found in the lateral aspects of femur and tibia and was primarily located within the femoral epiphysis. The metaphysis was not or only minimally affected in the evaluated longitudinal deficiencies. Awareness of sagittal instability, due to ACL and/or PCL aplasia, is necessary to avoid subluxation or dislocation when lengthening procedures are performed.

Introduction: The Taylor Spatial Frame (TSF) is a circular external fixator based on a hexapod system consisting of two carbon fiber rings connected with six telescopic struts. In conjunction with a software program the TSF allows for correction of deformities in 6 axis. After completion of the computer generated distraction plan a residual program can be used to correct any residual malalignment. Although the TSF received marketing clearance in 1997 and is used in specialized centers around the world, there is, up to date, only one MEDLINE report of two cases treated with the TSF. We present the results of 48 cases of limb lengthening and/or deformity correction using the TSF frame.

Patients and Methods: Between June 1999 and Septem-ber 2002 we implanted a total of 102 Taylor Spatial Frames (TSF). Only cases with a minimum follow up of 6 months after removal of the frame were included in our retrospective study. Thirty-six patients with a total of 48 TSF fixators met the inclusion criteria. The 23 female and 13 male patients had a mean age of 16 years (range:4-49). Eleven cases showed a post-traumatic deformity,13 cases a metabolic, 9 a congenital, 8 a osteodysplastic deformity and 7 showed various underlying pathologies. Seven TSF frames were implanted on the femur, whereas the remaining 41 frames were applied to the tibia.

Results: In 25 cases lengthening was the main treatment goal and in 23 cases the TSF was applied for angular or rotational deformity correction. The mean lengthening achieved in the group of patients treated was 40 mm (range: 20-70) and a mean healing index of 52.73 days/cm (28-105). In the patients who were treated to correct a deformity, the mean healing index was 159.69 days/cm (88-276). The highest mean healing index (178.91 days/cm) was found in patients where a metabolic disease was the underlying pathology, whereas patients treated for congenital lateral longitudinal defects showed the lowest mean healing index (53.25 days/cm). Complications included a superficial pin infection occurred in 66.6 % of the cases. There was no case of deep infection . Further complications were temporary postoperative sensory disturbance in 2 cases, premature consolidation of the fibula requiring re-oste-otomy in 2 cases, femoral fracture after removal of the frame in one case and dislocation of the frame with the need to change the position of a pin in another case. There were no hardware associated complications. A residual program was generated in 15 cases, 3 cases needed 2 and one case 4 residual programs to achieve the desired correction.

Conclusion: The healing index varied widely within our patient population. We assume that the healing index is not applicable to the correction of angular or rotational deformities with a lengthening less than 2 cm. The possibility of performing residual correction in all axis without the need to change the frame setup is a main advantage of the TSF and is very time saving during follow up examinations. Preoperative frame assembly is easy and fast compared to the standard Ilizarov system. A computer printed day-by-day prescription of strut adjustments makes it easy for the patient to perform the distraction and augments patient compliance.