How to cite this article:
Abe Y, Shimada M, Takeda Y, Enoki T, Omachi K, Abe S. Evaluation of Patient Positioning during Digital Tomosynthesis and Reconstruction Algorithms for Ilizarov Frames: A Phantom Study. 2020; 15 (1):1-6.
Aim: Metallic components from circular external fixators, including the Ilizarov frame, cause artefacts on X-rays and obstruct clear visualisation of bone detail. We evaluated the ability of tomosynthesis to reduce interference on radiographs caused by metal artefacts and developed an optimal image acquisition method for such cases.
Materials and methods: An Ilizarov frame phantom was constructed using rods placed on the bone for the purpose to evaluate the benefits of tomosynthesis. Distances between the rod and bone and the angle between the rod and X-ray tube orbit were set at three different levels. Filtered backprojection images were reconstructed using two different features of the reconstruction function: THICKNESS−− (CONTRAST4) and THICKNESS++ (METAL4); the first is suitable for improving contrast and the second is suitable for metal artefacts. The peak signal-to-noise ratio (PSNR) was used during image evaluation to determine the influence of the metallic rod on bone structure visibility.
Results: The PSNR increased as the angle between the metal rod and the X-ray tube orbit and the distance between the metallic rod and bone increased. The PSNR was larger when using THICKNESS−− (CONTRAST4) than when using THICKNESS++ (METAL4).
Conclusion: The optimal reconstruction function and image acquisition determined using the metallic rod in this study suggest that quality equal to that without the metallic rod can be obtained.
Clinical significance: We describe an optimised method for image acquisition without unnecessary acquisition repetition and unreasonable posture changes when the bone cannot be adequately visualised.
Peter H Thaller,
How to cite this article:
Thaller PH, Frankenberg F, Degen N, Soo C, Wolf F, Euler E, Fürmetz J. Complications and Effectiveness of Intramedullary Limb Lengthening: A Matched Pair Analysis of Two Different Lengthening Nails. 2020; 15 (1):7-12.
Background: Intramedullary limb lengthening has become an accepted concept in reconstructive surgery, but as yet comparative clinical studies are missing. We compared the complications and effectiveness of two types of intramedullary limb lengthening devices (ISKD®; Fitbone®).
Materials and methods: In a retrospective series of 278 consecutive patients with internal limb lengthening, we found 17 matching pairs in terms of predefined matching parameters (group I with ISKD® and group II with Fitbone®). The surgeries were all performed with the same technique and managed with equivalent pre- and postoperative treatment protocols. The performance of the implants was evaluated using the distraction index and the weight-bearing index. Complications were rated according to Paley\'s classification for external lengthening.
Results: The distraction index in group I (ISKD®) was 0.99 mm/day (range 0.55–1.67) and in the group II (Fitbone®) 0.55 mm/day (range 0.14–0.92) (p value = 0.001). The mean weight-bearing index differed between group I and group II from 32.0 day/cm (range 16.4–64.0) to 51.6 day/cm (25.8–95.0) (p value = 0.001). There were 17 recorded incidents in group I and 19 in group II during lengthening.
Conclusion: Specific technical handicaps of the two systems, such as the so-called runaway of the ISKD® and backtracking of the Fitbone® nails seem to result in different distraction index and weight-bearing index. Further comparative studies might induce technical progress in intramedullary limb lengthening.
The surgical technique of proximal tibial osteotomy for genu varum in adults has evolved from a procedure using closing wedges of estimated sizes with staple fixation in the 1960s to using standard trauma internal fixation implants and, more recently, to gradual correction with software-guided hexapod external fixators. In the last two decades, implant manufacturers have also produced anatomical implants specific for such corrective osteotomies. This study evaluates the limits of using such proprietary implants for proximal tibial osteotomy in genu varum.
Materials and methods: Scanograms (teleradiograms) of lower limbs of a patient were used to derive skiagrams (two-dimensional bony outlines of the extremities). From these, two-dimensional and three-dimensional models of varus deformities of the tibia with different values of mechanical medial proximal tibial angle (mMPTA, from 85° to 40°) were created. An analysis of the created deformity was carried out and a simulation for surgical correction was performed using an open wedge high tibial osteotomy with fixation using a proprietary (Tomofix, Synthes) implant. In addition, a 3D simulation technique was used to check the accuracy of the results obtained from the 2D simulation.
• In cases of mMPTA ≥80° with localisation of the apex of varus deformity at the level of the knee joint line, the standard technique used with the proprietary medial tibial plate produces good results.
• In cases of mMPTA ≤70°, fixation of the osteotomised fragments by the proprietary medial plate is poor owing to the anatomical contours of the implant. In these cases, a different type of osteosynthesis is needed.
• In cases of mMPTA ≤70°, the distance between the lower edge of the bone plate and the medial surface of the tibia after a proximal tibial osteotomy exceeds 11 mm and will result in unacceptable soft tissue tension around the implant.
• Mechanical axis deviation to the Fujisawa point produces mMPTA values outside the reference range of normal values.
Conclusion: An osteotomy of the proximal tibia using a prescribed technique linked to a proprietary implant achieves good results only if performed within a certain range of deformity values. Pronounced varus deformities require a fundamentally different approach. This study reveals that surgeons undertaking corrective proximal tibial osteotomies for genu varum need to perform a comprehensive analysis of the deformity to allow for appropriate selection of patients. This will enable a consideration of the size and other characteristics of the deformity that will reduce the technical complications that may arise if the correction was performed using the recommended technique linked to a proprietary implant.
How to cite this article:
Thiart G, Herbert C, Sivarasu S, Gasant S, Laubscher M. Influence of Different Connecting Rod Configurations on the Stability of the Ilizarov/TSF Frame: A Biomechanical Study. 2020; 15 (1):23-27.
Aim: The Ilizarov external fixator (IEF) is frequently used in trauma and elective orthopaedics. Many of its biomechanical variables (ring size, wire diameter, wire number, half pins vs wires, etc.) and their influence on stability and stiffness have been investigated. There is, however, a paucity in the literature regarding the influence of the connecting rod numbers and configurations between the rings on IEF stability. The primary aim of this biomechanical study was to compare the stability between four- and three-rod IEF configurations. Secondarily to assess the difference in stability between symmetrical and asymmetrical spacing of the IEF rods.
Materials and methods: A custom jig was designed to facilitate mounting of a basic two-ring IEF in a hydraulic press. Controlled centre and off-centre (thus simulated bending) axial loading was then applied across the frame. The configurations were loaded up to 4,000 N. The frame deformation was plotted and the data were then analysed and interpreted.
Results: Negligible differences were observed between different four- and three-rod configurations as long as the applied force at the loading point (LP) was within the area of support (AOS) created by the rods. The different four-rod constructs were always more stable than the three-rod constructs during bending.
Conclusion: There is comparable stiffness between a four-rod and a three-rod IEF construct as long as the LP is within the AOS created by the rods. A four-rod IEF is stiffer than a three-rod IEF in bending.
Clinical significance: This study will possibly change some paradigms regarding the planning and application of IEFs by Orthopaedics Traumatologists and Reconstruction Surgeons.
Background: An equinus deformity interferes with activities of daily living. Correction of the deformity ranges from conservative (heel cord stretching, orthotics) to surgical treatment (Baumann, Strayer, Achilles lengthening, soft tissue releases). Severe contractures increase surgical intervention with extensive dissections to release soft tissues. This study investigated the clinical outcomes of gradual overcorrection using a Taylor spatial frame (TSF) with tendo-Achilles lengthening (TAL) added as necessary.
Materials and methods: This retrospective chart review evaluated patients with significant equinus treated with a TSF at a single large tertiary referral centre. Data collected included: diagnosis; patient demographics; laterality; time in frame; additional procedures; complications; degree of equinus deformity preoperatively and at every follow-up visit. Patients were followed at 1 week, 3 weeks, 6 weeks, 3 months, and 6 months intervals, and yearly thereafter.
Results: Twenty-four patients (26 procedures) were treated with a TSF for equinus and had complete preoperative and follow-up measurements over 2 years. The angle of deformity increased from a preoperative −21.5 (range, −69.0 to −1.0) degrees to a postoperative 4.9 (range, −17.0 to 17.0) degrees (z = −4.4573, p = 0.0001, N = 26, Wilcoxon signed-rank test). A secondary outcome was a weak association (not statistically significant) between time in the TSF and the postoperative deformity angle. Four complications occurred during the follow-up (two pin site infections, one broken pin, and one plantar abscess). Three patients had recurrence of equinus deformity at time of last follow-up.
Conclusion: Using a TSF for correcting severe, fixed equinus contractures of the ankle joint is successful with minimal soft tissue-related complications. Overcorrection should be achieved in order to compensate for the loss of some dorsiflexion after frame removal. No added benefit was observed from having the frame on for a long time after correcting the deformity. Adding TAL is not necessary in all cases and required only in severe deformities of more than 25°.
Binu T Kurian,
Sanjeev S Madan,
James A Fernandes
Aim and objective: Ilizarov hip reconstruction (IHR) is a traditional method of salvaging chronic adolescent problem hips but faces practical issues from external fixators leading to reduced compliance. We present the same reconstruction procedure using only internal devices with a modification in the technique and review early results.
Materials and methods: We retrospectively evaluated eight patients between 2014 and 2017 with chronic painful hips treated by two-stage reconstruction; stage I included femoral head resection and pelvic support osteotomy using double plating, whereas stage II comprised distal femoral osteotomy avoiding varus followed by the insertion of a retrograde magnetic nail for postoperative lengthening. Patients continued physiotherapy postoperatively while protecting from early weight-bearing.
Results: At a mean follow-up of 19 months (range, 6−36), all osteotomies healed with a bone healing index of 47 days/cm (range, 30−72). Pain improved from 8.3 (range, 7−9) to 2 (range, 0−6) while the limb length discrepancy got corrected from 4.3 cm (range, 3−5) to 1.4 cm (range, 0−2.5) at the final follow-up. Trendelenburg sign was eliminated in three patients and delayed in five patients. No examples of infection or permanent knee stiffness were noted. One patient had plate breakage due to mechanical fall, and another patient had 35 mm of lateral mechanical axis deviation (MAD) requiring corrective osteotomy.
Conclusion: Pelvic support hip reconstruction with exclusive internal devices is a technique in evolution with encouraging early results. It avoids common complications of external fixators and facilitates quick rehabilitation of joints. Refraining from distal varus can effectively eliminate Trendelenburg gait, although with some degree of lateral MAD. Unlike external fixation where there is a possibility of gradual correction, this staged procedure of internal fixation is technically demanding with a learning curve.
Clinical significance: Pelvic support hip reconstruction performed by internal implants is a viable alternative to Ilizarov hip reconstruction with potential benefits.
Introduction: There 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 methods: A 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.
Results: A 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.
Conclusion: The 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.
Introduction: The anterior approach to a tibial osteotomy commonly employs a small incision and multiple drill holes followed by completion with an osteotome. Potential complications are damage to the anterior tibial periosteum and posterior neurovascular structures.
Materials and Methods: We describe an alternative method using two small incisions, which avoids elevation of the anterior tibial periosteum and directs the osteotome away from posterior neurovascular structures.
Results: This technique has been successfully performed on 15 consecutive tibias, with no neurovascular complications or skin healing issues.
Conclusion: This tibial osteotomy technique can be performed quickly and safely using a minimally invasive approach as an alternative to the traditional anterior approach.
Background: Various surgical treatments have been advocated for stump pain and phantom limb pain after limb amputation but the most effective is unknown. We report a case of intractable stump pain and phantom limb pain of the upper limb, which was successfully treated by end-to-end coaptation of the cutaneous nerves after multimodal treatment failures.
Case description: A 39-year-old man was referred to our department with a history of severe stump neuroma-related pain and phantom limb pain of his right upper limb. He had undergone multiple treatments over 26 years including medication, nerve blocks, and repeated surgeries. None had been successful for relief of pain. The clinical assessment showed a point of marked tenderness around the medial stump of the upper arm. Ultrasound-guided peripheral infiltration of local anaesthetic around the medial stump produced significant relief of his pain. Exploration around the medial limb stump revealed two stump neuromas of the medial cutaneous nerves of the forearm. Both stump neuromas were resected, and their stumps were coapted to each other. After 4 years, he was completely relieved of his pain and without any sensory deficit.
Conclusion: Successful nerve coaptations for painful stump neuromas of the upper limb are reported rarely. This case suggests this method can be helpful. The patient burden was minimal because it involved the resection and coaptation of the two neuromas. This method should be encouraged for cases of intractable stump-related pain in the upper limb.
Ahmed H Barakat,
How to cite this article:
Barakat AH, Sayani J, O\'Dowd-Booth C, Guryel E. Lengthening Nails for Distraction Osteogenesis: A Review of Current Practice and Presentation of Extended Indications. 2020; 15 (1):54-61.
Purpose: Circular frames have been the gold standard of treatment for complex deformity corrections and bone loss. However, despite the success of frames, patient satisfaction has been low, and complications are frequent. Most recently, lengthening nails have been used to correct leg length discrepancies. In this article, we review the current trends in deformity correction with emphasis on bone lengthening and present our case examples on the use of lengthening nails for management of complex malunions, non-unions, and a novel use in bone transport.
Materials and methods: A nonsystematic literature review on the topic was performed. Four case examples from our institute, Brighton and Sussex University Hospitals, East Sussex, England, UK, were included.
Results: New techniques based on intramedullary bone lengthening and deformity correction are replacing the conventional external frames. Introduction of lengthening and then nailing and lengthening over a nail techniques paved the way for popularization of the more recent lengthening nails. Lengthening nails have gone through evolution from the first mechanical nails to motorized nails and more recently the magnetic lengthening nails. Two case examples demonstrate successful use of lengthening nails for management of malunion, and two case examples describe novel use in management of non-unions, including the first report in the literature of plate-assisted bone segment transport for the longest defect successfully treated using this novel technique.
Conclusion: With the significant advancement of intramedullary lengthening devices with lower complications rates and higher patient satisfaction, the era of the circular frame may be over.