Knee dislocations, vascular injuries and floating knee injuries can be initially managed by a external fixator. Fixator design constructs include the AO pattern and the Diamond pattern. However, these traditional constructs do not adhere to basic principles of external fixation. The Manchester pattern knee-spanning external fixator is a new construct pattern, which uses beam loading and multiplanar fixation. There is no data on any construct pattern. This study compares the stability of these designs. Hoffman III (Stryker, USA) external fixation constructs were applied to articulated models of the lower limb, spanning the knee with a diamond pattern and a Manchester pattern. The stiffness was loaded both statically and cyclically with a Bose 3510 Electroforce mechanical testing jig (TA Instruments). A ramp to load test was performed initially and cyclical loading for measurement of stiffness over the test period. The results were analysed with a paired t-test and ANOVA.Introduction
Materials & Methods
To compare the functional outcome of Distal Tibial Metaphyseal fracture treated with Circular frame compared vs. Locking Plate Distal Tibial Metaphyseal fractures were retrospectively identified over an 18 month period. Each fracture was assessed individually using radiographs. All paediatric, compound, tibial plateau and intra-articular fractures were excluded from the study. Other methods of fixation including intramedullary nailing were also excluded. The remaining fractures were assigned to either the circular frame fixation or the locking plate intervention group. Outcomes were assessed using radiographs for union dates and microbiology results for evidence of infection. Patients were followed up by postal questionnaires, which included a modified American Orthopaedic Foot and Ankle Score (AOFAS), the Olerud and Molander Score (O&M) and a custom questionnaire. The custom questionnaire asked about co-morbidities, smoking status and work days lost following surgery. After exclusions, 30 patients (Frame=15, Plate=15), were sent out questionnaires via post. We received completed questionnaires from 21 patients (Frame=11, Plate=10) giving us a response rate of 70%. Results show no difference in infection rates, skin necrosis, non-union or re-operation rates. There was also no significant difference in patient AOFAS and O&M scores at follow up.Statement of Purpose
Methods and Results
Taylor Spatial Frame (TSF) is a six axis deformity correction frame and accuracy of correction depend on the accuracy of parameters input in to the web based software. There are various methods of obtaining frame and deformity parameters (13 in total) including the use of dedicated software known as SpatialCAD™. We tested the accuracy of SpatialCAD™ using a saw bone two ring frame construct of known parameters. We mounted a two-ring (155mm) frame on a saw bone tibia and fibula unit and worked out the accurate mounting and deformity parameters. Then we obtained orthogonal and nonorthogonal antero-posterior and lateral images of frame using a metallic sphere of known dimensions placed at the level of the bone, to aid calibration of x-ray images. We also obtained orthogonal and non-orthogonal images without a calibrating sphere. We then uploaded the images in to SpatialCAD™ software and obtained the mounting and deformity parameters and compared with the real parameters. SpatialCAD™ is capable of yielding measurements within 1–2mm of actual measurements when Calibrated orthogonal images were used. The software was inaccurate when frame hardware of known dimensions was used for calibration because the hardware was not in the same plane as the bone
Limb lengthening with external fixators has many complications, like pin track infection, joint stiffness, severe pain and stress fracture after removal of external fixator. Prolonged period in external fixator interferes with rehabilitation and activities of daily living. We describe our results with ISKD (intramedullary skeletal kinetic distractor) system, an internal limb lengthening device, activated with rotations of 3 degrees. In this retrospective cohort we performed lengthening with the use of ISKD in 12 patients from March 2006 to date. Ten patients were included in this study as two patients had not completed the stage of consolidation. There were 7 male and 3 female patients. Their average age was 44 years (range 23–63). The mean follow up period was 16 months (range 12–24 months). Two patients had tibial lengthening and eight patients had femoral lengthening. The average lengthening desired was 42.5 mm (range 2.5 mm–75 mm). The average lengthening achieved was 38 mm. Mean hospital stay was 7 days (range 5–11 days). The distraction index was 1.2 mm/day. The average time to full weight bearing was 6 months (range 4 to 10 months). Mean healing time was 10.25 months. The mean healing index was 90.7 days/cm. If we remove two patients who took long time to heal, the mean healing index drops to 61 days/cm. Two patients needed bone grafting at the distraction site. None of the patients had infection, non-union of the distraction site or breakage of the nail. None of the patients had joint stiffness. All patients were completely satisfied with the treatment and had excellent functional results. We conclude that the low rate of complications, higher patient acceptability and avoidance of external fixation make ISKD a very attractive option for limb lengthening.
