Fixator-assisted Plating Research Articles

External fixator-assisted plating osteosynthesis in a rabbit model of femoral bone defects appears to be a feasible and reproducible surgical technique: preliminary insights from a bone substitute study

PurposeThe aims of this study were to assess the complications associated with the use of an external fixator-assisted plate osteosynthesis technique to stabilize a femoral bone defect in a rabbit model and to evaluate if this technique could avoid the mispositioning and the displacement of the femoral fragments during the surgical procedure.MethodsA preliminary cadaveric animal study was conducted to develop a new technique of external fixator-assisted plating. Thirty rabbits underwent a surgical procedure consisting in the creation of a femoral bone defect and, subsequently an implantation of a bone substitute through the assistance of a temporary external fixator. The fixator’s ability to maintain length and alignment during surgery was documented. All intraoperative complications were prospectively collected.ResultsNo complications related to the use of the temporary external fixator were reported. The technique successfully prevented mispositioning and dislocation during plating in all the rabbits.ConclusionIn a rabbit animal model, the use of an external fixator-assisted plate osteosynthesis technique appears to be feasible and effective in avoiding misposition and rotation of femoral fragments when performing osteotomy and plating to create a mid-diaphyseal femoral defect.

Deformity Correction, Surgical Stabilisation and Limb Length Equalisation in Patients with Fibrous Dysplasia: A 20-year Experience

IntroductionFibrous dysplasia (FD) of bone can be present with pain, deformity and pathological fractures. Management is both medical and surgical. Little literature exists on the surgical management of both monostotic and polyostotic FD. We present our experience of limb reconstruction surgery in this pathological group of bone disease.Materials and methodsA retrospective cohort of children who underwent limb reconstruction surgery at a single high-volume paediatric centre was identified from a prospective database. Case notes and radiographs were reviewed. Surgical techniques, outcomes and difficulties were explored.ResultsTwenty-one patients were identified aged between 7 and 13 at presentation to the limb reconstruction unit. Eleven were female, nine had McCune-Albright syndrome, seven had polyostotic FD and five had monostotic. Proximal femoral varus procurvatum deformity was the most common site requiring surgical intervention. The distal femur, tibia, humerus and forearm were also treated.Methods include deformity correction with intramedullary fixation including endo-exo-endo techniques, elastic nailing, guided growth, circular fixator technique and fixator-assisted plating. Correction of deformity and leg length discrepancies was common.The osteotomies went on to heal with no nonunions or delayed healing. We encountered secondary deformity at distal end of nails as the children grew as expected. These were managed with revision nailing techniques and in some cases external fixation. There was one implant failure, which did not require revision surgery.ConclusionThe surgical management of pathological bone disease is challenging. Corrective osteotomies with intramedullary fixation can be very successful if appropriate limb reconstruction principles are adhered to. Deformity correction, guided growth and lengthening can all be successfully achieved in bone affected by FD. Polyostotic FD can be present with secondary deformities, and these can be difficult to manage.How to cite this articleHampton MJ, Weston-Simmons S, Giles SN, et al. Deformity Correction, Surgical Stabilisation and Limb Length Equalisation in Patients with Fibrous Dysplasia: A 20-year Experience. Strategies Trauma Limb Reconstr 2021;16(1):41–45.

One-stage correction of angular deformities around the knee using internal fixation

Background Deformity correction has been long performed using internal fixation. Since the introduction of external fixation in orthopedic practice, it has gained popularity in correcting severe deformities, and many orthopedic surgeons have resorted to external fixation to correct severe deformities. The authors asked if internal fixation can be safely used to correct significant deformities with marked mechanical axis deviation thus abolishing the notion that external fixation is the only available option to correct severe deformities. Patients and methods A single-center, prospective study was conducted at an academic center from October 2014 to December 2016. A total of 37 patients with lower limb deformities were included in the study. Overall, 13 patients were corrected using locked plates and 24 patients were corrected using intramedullary nails. The average follow-up was 13.5 months (10–18 months). Results The desired correction was achieved in all patients. Union was quicker with plates, but this could be attributed to the younger age of patients in that group. Discussion Many methods of fixation have been used to correct angular deformities around the knee. With patients’ satisfaction gaining utmost importance recently, surgeons have been revising their approach in managing various orthopedic conditions, and limb deformity is no exception. During the surgeons’ pursuit to achieve their patients’ maximum satisfaction without compromising the accuracy of correction or rigidity of fixation, two new techniques have emerged, namely, fixator-assisted plating and fixator-assisted nailing techniques, which represent a breakthrough in deformity correction, because they combine the advantages of internal and external fixation. The use of internal fixation usually yields higher patients’ satisfaction. Conclusion Internal fixation is a safe and effective treatment option for correcting significant deformities of the lower limb.

Accuracy and Safety of Distal Femoral Valgus Correction: A Comparison of Three Techniques.

IntroductionThere are several methods for correcting distal femoral valgus deformity in skeletally mature patients including fixator-assisted plating (FAP), fixator-assisted nailing (FAN) and nailing using the reverse planning method. The fixator-assisted techniques have been previously compared in the literature and found to be similarly accurate. This study is the first to compare all three procedures in a single series.Materials and methodsA retrospective review of patients who had undergone distal femoral valgus correction at a single institution between March 2017 and February 2020 was undertaken. Three different patient groups were identified based on the surgical technique used: the FAP, the FAN and the reverse planning method. The mechanical lateral distal fimoral angle (mLDFA) was recorded and compared preoperatively and postoperatively. The body mass index (BMI), duration of surgery, postoperative range of motion (ROM) and complication profile for each patient were also recorded and compared.ResultsA total of 27 limbs in 24 patients were included in this study. There were 8 male and 16 female patients. There were 10 limbs from 9 patients in the reverse planning group, 11 limbs from 11 patients in the FAN group and 6 limbs from 4 patients in the FAP group. There was a statistically significant difference in the mean preoperative and postoperative mLDFA for each of the individual groups (p < 0.0001 for each group). All patients had restoration of the mLDFA to within normal limits except one patient in the reverse planning group. This was purposefully performed to compensate for an ipsilateral proximal tibial deformity. There was no statistically significant difference in the mean preoperative and postoperative mLDFA across the groups (p = 0.2897 and 0.3440, respectively). The operative time of the reverse planning method and the FAP were significantly shorter than FAN (p = 0.0016 and p = 0.0035, respectively). The mean final knee ROM amongst the groups was similar (p = 0.8190). We recorded no infections or union complications in any group. There was one case of hardware irritation causing lateral knee pain that did not require treatment in the reverse planning group and one fracture through a temporary half-pin site in the FAN group. All six plates in the FAP group had to be removed following union on account of localised discomfort from the hardware.ConclusionThe reverse planning method, the FAN and the FAP are comparable in terms of accuracy in achieving correction of distal femur valgus deformity in skeletally mature patients. The reverse planning method had the best combination of outcomes in this study since it was just as accurate as the FAN and the FAP techniques and did not require any additional surgeries. While both the reverse planning and the FAP were faster than the FAN technique, the reverse planning method allows the ability to perform both deformity correction and lengthening. Ultimately, the decision of which technique to use depends on a combination of the patient's preference and the surgeon's level of comfort with the technique.How to cite this articleIobst C, Waseemuddin M, Bafor A. Accuracy and Safety of Distal Femoral Valgus Correction: A Comparison of Three Techniques. Strategies Trauma Limb Reconstr 2020;15(1):41–46.

Correction of distal femoral valgus deformities with fixator-assisted plating: How accurate is the correction?

ObjectiveThe aim of this study was to evaluate the results of fixator assisted correction of the distal femoral valgus deformities and the precision of the correction. MethodsSeventeen extremities of 13 patients (7 women and 6 men; mean age: 16 ± 5.4 years) who had fixator assisted plating of the distal femur for genu valgum deformity were evaluated. Mechanical axis deviation (MAD) and mechanical lateral distal femoral angles (mLDFA) were measured pre-operatively and post-operatively. mLDFA was graded as perfect if it is between 85° and 90°(85° ≤ x ≤ 90°); overcorrection if it is between 91° and 95° (91° ≤ x ≤ 95°) and undercorrection if it is between 80° and 85° (80° ≤ x < 85°). Measurements beyond those limits were graded as a poor result. The position of the mechanical axis line with respect to center of the knee was graded from zone 1 to zone 4 pre-operatively and post-operatively. ResultsThe mean follow-up period was 12.8 ± 3.7 months. The pre-operative and post-operative mLDFA was 70.5°±9.4° (range, 57°–82°) and 87.7° ± 3.5° (range, 80°–94°), respectively (p < 0.001). Based on post-operative standing radiographs, the correction was graded perfect in 12 femurs. The correction in three femurs were graded as overcorrection and graded as undercorrection in two femurs. Sagittal plane correction was also achieved in two femurs. Peroneal nerve decompression was done in three patients (5 extremities) with valgus deformity over 30°. The mechanical axes in all lower extremities were passing through zone 2 or more, pre-operatively, whereas the mechanical axes were in zone 2 or more in five extremities post-operatively. ConclusionFixator assisted plating is an effective treatment modality in patients with distal femoral valgus deformity. Although the technique enables to obtain significant correction in coronal plane it has the disadvantages of over- and undercorrection. Thus, we advise intraoperative confirmation of the correction under fluoroscopic control.Level of Evidence: Level IV Therapeutic Study.

Comparison of fixator-assisted plating versus fixator-assisted nailing for distal femoral osteotomy

Introduction: Fixator-assisted plating (FAP) and fixator-assisted nailing (FAN) have gained popularity recently in correcting deformities due to their advantage of combining the accuracy of deformity correction offered by external fixator (that is removed at the end of surgery) with the convenience of internal fixation for osteotomy fixation. The advantage of one method over the other is not yet clear and there are limited reviews in literature in this regard. We asked whether one technique has an advantage over the other as regards the ability to correct the deformity, blood loss, knee range, time to union, and complication rate. Methods: We identified 18 patients who underwent distal femoral osteotomies, 6 patients underwent FAP and 12 patients underwent FAN. We compared the accuracy of correction, duration of surgery, preoperative and postoperative knee range, and complications. Minimum follow-up was 13.4 months (6–18 months). Plates were used in skeletally immature patients or in skeletally mature patients with thin thighs, while nails were used in skeletally mature patients with big thighs. Results: We achieved the desired correction in all the 18 patients. Union was quicker with plates, but this could be attributed to the younger age of patients in that group. There was no statistically significant difference between both techniques that may point out that one method is superior to the other as regarding deformity correction (based on percentage improvement in mechanical axis deviation as compared preoperatively and at final follow-up). Preoperative and postoperative knee ranges were similar for both techniques and there was only one case of recurrence that had bone softening disease. Conclusion: Both techniques can be used to achieve correction with no statistically significant differences, and the choice between both techniques can be left to surgeons' or patients' discretion.Level of Evidence: Level III, therapeutic study.

Can fixator-assisted plating of focal dome osteotomy accurately correct varus deformity in medial compartment osteoarthritis?

Large varus deformities in medial compartment osteoarthritis are difficult to correct with lateral closing-wedge or medial opening-wedge osteotomies. They are easier to correct gradually with opening-wedge or dome osteotomies with external fixation. A focal dome osteotomy can support a large angular correction and yet retains good bony contact. It creates a large proximal fragment that allows for better fixation. However, external fixation devices are cumbersome and not well tolerated by older women and those who cannot follow-up over long distances. Fixator-assisted plating of the focal dome osteotomy combines the advantages of the fixator for accuracy of correction and the convenience of the locking plate. We retrospectively analyzed 34 focal dome high-tibial osteotomies in 31 patients performed over 6 years. Preoperative mechanical axis deviation was −19% (−150%-28%) which improved to 55% (3%-108%). The average preoperative medial proximal tibial angle was 79.8° (88°-63°) which improved to 93° (84°-107°). The average preoperative hip-knee-ankle angle was 195.2° (185°-225°) which improved to 177.5° (166°-204°). Femorotibial angle was 184.6° (182°-220°) which improved to 172° (158°-184°). The tibial slope reduced from 76.9° to 81.1°. Average follow-up was 70 months (45-113). Large varus deformities could be corrected safely with reasonable accuracy in this study.

Correction of distal femoral valgus deformities in adolescents and young adults using minimally invasive fixator-assisted locking plating (FALP)

The treatment of distal femoral valgus deformities in skeletally mature patients might be a challenging surgical problem with significant morbidity. Treatment options are various and include osteotomy and external fixation, intramedullary nailing, and plating using standard and locking plates. We describe technical notes of minimally invasive technique of fixator-assisted plating using a supracondylar locking plate. During a period of 3 years, we operated on six patients (seven femurs) with distal femoral valgus deformities of different etiologies. All patients achieved correction of the deformities and started full weight bearing with radiographic evidence of union 6 weeks after correction. We believe that fixator-assisted locking plating has advantages over correction using external fixation and intramedullary nailing. This method of correction can be performed by a minimally invasive technique, precisely, and with minimal morbidity.

Fixator-Assisted Plating of Limb Deformities

Fixator-assisted plating of the distal femur and proximal tibia can be used for accurate and effective correction of acute deformity. The advantage of this hybrid technique is that one can use the best of both internal and external fixation. The external fixator is applied in a fashion that does not impede insertion of the plate. The neutral wedge osteotomy is then performed in a minimally invasive fashion. The fixator is used to incrementally correct the deformity over several minutes in a controlled and gradual fashion in the operating room. Complex deformity correction, including angulation and translation in the coronal, sagittal, and axial planes, can be gradually adjusted. The surgeon maintains control of the osteotomy, and the position can be checked with x-ray and/or computer navigation. The fixator may be further adjusted to tweak the position as needed. Once alignment is optimal, a locked plate is inserted through a minimal incision technique to maintain the position, allowing removal of the fixator.

Distal Femoral Osteotomy: Is Internal Fixation Better than External?

Distal femoral osteotomies (DFO) can be used to correct deformities around the knee. Although osteotomies can be fixed with either internal or external fixation techniques, the advantages of one over the other are unclear. We asked whether (1) for both techniques, we could accurately correct the deformities based on our preoperative goals for mechanical axis deviation (MAD) and lateral distal femoral angle (LDFA), and (2) intraoperative times, (3) preoperative and postoperative knee ROM, and (4) complications differed. We identified 26 patients (34 limbs) who underwent femoral osteotomies. We compared accuracy of correction (based on correction of the MAD and the LDFA), duration of surgery, preoperative and postoperative knee ROM, and complications. The minimum followup was 20 months (mean, 29 months; range, 20-40 months). We achieved the desired MAD within 10 mm of the goal in 18 of 21 limbs with the unilateral frame and in 12 of 13 limbs using fixator-assisted plating. Operative time for fixator-assisted plating was longer (122 ± 34 minutes) than when using a unilateral frame (94 ± 65 minutes). Preoperative and postoperative knee ROMs were similar for both techniques and there were no major complications. We obtained accurate correction of deformities with both fixation techniques. Our experience suggests the method to be used should be left to the discretion of the surgeon and the needs and wishes of the patient after adequate explanation of the advantages and disadvantages. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.