Aims

Aseptic loosening of the tibial component is a frequent cause of failure in primary total knee arthroplasty (TKA). Management options include an isolated tibial revision or full component revision. A full component revision is frequently selected by surgeons unfamiliar with the existing implant or who simply wish to “start again”. This option adds morbidity compared with an isolated tibial revision. While isolated tibial revision has a lower morbidity, it is technically more challenging due to difficulties with exposure and maintaining prosthetic stability. This study was designed to compare these two reconstructive options.

We reviewed three infants with destructive osteomyelitis involving the proximal tibial epiphysis at a follow-up of eight to 22 years. All cases showed early radiographic destructive changes in the medial or lateral aspects of the epiphysis and metaphysis. Despite the ominous early appearance of the epiphysis, all cases showed spontaneous re-ossification of the epiphysis with restoration of the tibial condyle and preservation of joint congruity. The patients, however, developed a valgus or varus deformity which was treated satisfactorily with one to three proximal tibial osteotomies. The potential for regeneration of the epiphysis following infantile osteomyelitis of the proximal tibia suggests these cases should be treated expectantly with regard to joint congruity

We prospectively assessed the benefits of using either a range-of-movement technique or an anatomical landmark method to determine the rotational alignment of the tibial component during total knee replacement. We analysed the cut proximal tibia intraoperatively, determining anteroposterior axes by the range-of-movement technique and comparing them with the anatomical anteroposterior axis. We found that the range-of-movement technique tended to leave the tibial component more internally rotated than when anatomical landmarks were used. In addition, it gave widely variable results (mean 7.5°; 2° to 17°), determined to some extent by which posterior reference point was used. Because of the wide variability and the possibilities for error, we consider that it is inappropriate to use the range-of-movement technique as the sole method of determining alignment of the tibial component during total knee replacement

We have examined the relationship between the size of the flexion gap and the anterior translation of the tibia in flexion during implantation of a posterior cruciate ligament (PCL)-retaining BalanSys total knee replacement (TKR). In 91 knees, the flexion gap and anterior tibial translation were measured intra-operatively using a custom-made, flexible tensor-spacer device. The results showed that for each increase of 1 mm in the flexion gap in the tensed knee a mean anterior tibial translation of 1.25 mm (SD 0.79, 95% confidence interval 1.13 to 1.37) was produced. When implanting a PCL-retaining TKR the surgeon should be aware that the tibiofemoral contact point is related to the choice of thickness of the polyethylene insert. An additional thickness of polyethylene insert of 2 mm results in an approximate increase in tibial anterior translation of 2.5 mm while the flexed knee is distracted with a force of between 100 N and 200 N

Aims

Although knee osteoarthritis (OA) is diagnosed and monitored radiologically, actual full-thickness cartilage loss (FTCL) has rarely been correlated with radiological classification. This study aims to analyze which classification system correlates best with FTCL and to assess their reliability.

Introduction

The primary aim of this study was to describe a baseline comparison of early knee-specific functional outcomes following revision total knee arthroplasty (TKA) using metaphyseal sleeves with a matched cohort of patients undergoing primary TKA. The secondary aim was to compare incidence of complications and length of stay (LOS) between the two groups.

We present a retrospective review of 167 patients aged 18 years and under who were treated for chronic haematogenous osteomyelitis at our elective orthopaedic hospital in Malawi over a period of four years. The median age at presentation was eight years (1 to 18). There were 239 hospital admissions for treatment during the period of the study. In 117 patients one admission was necessary, in 35 two, and in 15 more than two. A surgical strategy of infection control followed by reconstruction and stabilisation was employed, based on the Beit CURE radiological classification of chronic haematogenous osteomyelitis as a guide to treatment. At a minimum follow-up of one year after the end of the study none of the patients had returned to our hospital with recurrent infection. A total of 350 operations were performed on the 167 patients. This represented 6.7% of all children’s operations performed in our hospital during this period. One operation only was required in 110 patients and none required more than three. Below-knee amputation was performed in two patients with chronic calcaneal osteomyelitis as the best surgical option for function. The most common organism cultured from operative specimens was Staphylococcus aureus, and the tibia was the bone most commonly affected. Polyostotic osteomyelitis occurred in four patients. We believe this is the largest reported series of patients treated for chronic haematogenous osteomyelitis

Objectives. The most concerning infection of allografts and operative procedures is methicillin resistant Staphylococcus aureus (MRSA) and no current iontophoresed antibiotics effectively combat this microbe. It was initially hypothesised that iontophoresis of vancomycin through bone would not be effective due to its large molecular size and lack of charge. The aim of this study was to determine whether this was a viable procedure and to find the optimum conditions for its use. . Methods. An iontophoresis cell was set up with varying concentrations of Vancomycin within the medulla of a section of sheep tibia, sealed from an external saline solution. The cell was run for varying times, Vancomycin concentrations and voltages, to gain information on optimisation of conditions for impregnating the graft. Each graft was then sectioned and dust ground from the exposed surface. The dust was serially washed to extract the Vancomycin and concentrations measured and plotted for all variables tested. Results. Vancomycin was successfully delivered and impregnated to the graft using the iontophoresis technique. The first order fit to the whole data set gave a significant result (p = 0.0233), with a significant concentration (p = 0.02774) component. The time component was the next most significant (p = 0.0597), but did not exceed the 95% confidence level. Conclusions. Iontophoresis is an effective method for delivering Vancomycin to allograft bone. The concentrations of the vancomycin solution affected the bone concentration, but results were highly variable. Further study should be done on the effectiveness of delivering different antibiotics using this method. Cite this article: Bone Joint Res 2014;3:101–7

We reviewed our initial seven-year experience with a non-invasive extendible prosthesis in 34 children with primary bone tumours. The distal femur was replaced in 25 cases, total femur in five, proximal femur in one and proximal tibia in three. The mean follow-up was 44 months (15 to 86) and 27 patients (79%) remain alive. The prostheses were lengthened by an electromagnetic induction mechanism in an outpatient setting and a mean extension of 32 mm (4 to 80) was achieved without anaesthesia. There were lengthening complications in two children: failed lengthening in one and the formation of scar tissue in the other. Deep infection developed in six patients (18%) and local recurrence in three. A total of 11 patients required further surgery to the leg. Amputation was necessary in five patients (20%) and a two-stage revision in another. There were no cases of loosening, but two patients had implant breakage and required revision. The mean Musculoskeletal Tumor Society functional score was 85% (60% to 100%) at last known follow-up. These early results demonstrate that the non-invasive extendible prosthesis allows successful lengthening without surgical intervention, but the high incidence of infection is a cause for concern

Aims

To report mid- to long-term results of Oxford mobile bearing domed lateral unicompartmental knee arthroplasty (UKA), and determine the effect of potential contraindications on outcome.

1. The probable greatest bending moment applied to a plated or nailed fracture of the tibia during restricted weight-bearing is estimated to be, in men, up to about 79 Newton metres (58 poundsforce feet). The maximum twisting moment is estimated to be about 29 Newton metres (22 poundsforce feet). 2. Twenty-two human tibiae were loaded in three-point bending and broke at bending moments of from 57·9 to 294 Newton metres (42·7 to 216 poundsforce feet) if they had not previously been drilled; tibiae which had holes made through both cortices with a c. 3-millimetre (⅛-inch) drill broke at from 32·4 to 144 Newton metres (23·8 to 106 poundsforce feet). Tibiae loaded in torsion broke at twisting moments of from 27·5 to 892 Newton metres (20·2 to 65·8 poundsforce feet) when not drilled, 23·6 to 77·5 Newton metres (l7·3 to 57·1 poundsforce feet) when drilled. 3. When bent so as to open the fracture site, the 14-centimetre Stamm was the strongest of all the single plates tested (reaching its elastic limit at a bending moment of 17·6 Newton metres (13 poundsforce feet) and 5 degrees total angulation at 22·6 Newton metres (16·6 poundsforce feet)), while the Venable was the weakest (elastic limit 4·9 Newton metres (3·6 poundsforce feet) and 5 degrees at 7·9 Newton metres (5·8 poundsforce feet)). A 13-millimetre Küntscher nail reached its elastic limit at 42·2 Newton metres (31·1 poundsforce feet) and 5 degrees total angulation at 49 Newton metres (36 poundsforce feet). 4. In torsion the 15-centimetre Hicks was the strongest ofthe plates (elastic limit 27·5 Newton metres (20·2 poundsforce feet) and 5 degrees rotation at 16·7 Newton metres (l2·3 poundsforce feet)). 5. Küntscher nails in bones provided no dependable strength in torsion. 6. In both bending and torsion, a preparation of one Venable plate on each of the two anterior surfaces was stronger than any single plate, and was as strong as the weaker drilled tibiae. 7. The three currently available metallic materials (stainless steel, cobalt-chrome and titanium) have static mechanical properties so similar that the choice between them can be made on other grounds. 8. The highest load applied to a screw during bending tests was about half that needed to pull a screw out of even a thin-walled tibia. 9. Screws beyond four for one plate are mechanically redundant at the moment of implantation but may be necessary as an insurance against subsequent deterioration in strength. 10. Countersinks in plates are a source of significant weakness, and should preferably be as shallow as possible. 11. An unoccupied screw hole in the centre of a plate is a source of serious weakness. 12. Only the strongest implants tested were strong enough to withstand the bending or twisting moments to be expected in restricted weight-bearing. In two-plate preparations a danger is introduced by the fact that these moments are similar to those required to Ireak a drilled tibia

A delay in the diagnosis of paediatric acute and subacute haematogenous osteomyelitis can lead to potentially devastating morbidity. There are no definitive guidelines for diagnosis, and recommendations in the literature are generally based on expert opinions, case series and cohort studies. All articles in the English literature on paediatric osteomyelitis were searched using MEDLINE, CINAHL, EMBASE, Google Scholar, the Cochrane Library and reference lists. A total of 1854 papers were identified, 132 of which were examined in detail. All aspects of osteomyelitis were investigated in order to formulate recommendations. On admission 40% of children are afebrile. The tibia and femur are the most commonly affected long bones. Clinical examination, blood and radiological tests are only reliable for diagnosis in combination. Staphylococcus aureus is the most common organism detected, but isolation of Kingella kingae is increasing. Antibiotic treatment is usually sufficient to eradicate the infection, with a short course intravenously and early conversion to oral treatment. Surgery is indicated only in specific situations. Most studies were retrospective and there is a need for large, multicentre, randomised, controlled trials to define protocols for diagnosis and treatment. Meanwhile, evidence-based algorithms are suggested for accurate and early diagnosis and effective treatment

Between 2005 and 2010 ten consecutive children with high-energy open diaphyseal tibial fractures were treated by early reduction and application of a programmable circular external fixator. They were all male with a mean age of 11.5 years (5.2 to 15.4), and they were followed for a mean of 34.5 months (6 to 77). Full weight-bearing was allowed immediately post-operatively. The mean time from application to removal of the frame was 16 weeks (12 to 21). The mean deformity following removal of the frame was 0.15° (0° to 1.5°) of coronal angulation, 0.2° (0° to 2°) sagittal angulation, 1.1 mm (0 to 10) coronal translation, and 0.5 mm (0 to 2) sagittal translation. All patients achieved consolidated bony union and satisfactory wound healing. There were no cases of delayed or nonunion, compartment syndrome or neurovascular injury. Four patients had a mild superficial pin site infection; all settled with a single course of oral antibiotics. No patient had a deep infection or re-fracture following removal of the frame. The time to union was comparable with, or better than, other published methods of stabilisation for these injuries. The stable fixator configuration not only facilitates management of the accompanying soft-tissue injury but enables anatomical post-injury alignment, which is important in view of the limited remodelling potential of the tibia in children aged > ten years. Where appropriate expertise exists, we recommend this technique for the management of high-energy open tibial fractures in children

The rotational alignment of the tibia is an unresolved issue in knee replacement. A poor functional outcome may be due to malrotation of the tibial component. Our aim was to find a reliable method for positioning the tibial component in knee replacement. CT scans of 19 knees were reconstructed in three dimensions and orientated vertically. An axial plane was identified 20 mm below the tibial spines. The centre of each tibial condyle was calculated from ten points taken round the condylar cortex. The tibial tubercle centre was also generated as the centre of the circle which best fitted eight points on the outside of the tubercle in an axial plane at the level of its most prominent point. The derived points were identified by three observers with errors of 0.6 mm to 1 mm. The medial and lateral tibial centres were constant features (radius 24 mm (. sd. 3), and 22 mm (. sd. 3), respectively). An anatomical axis was created perpendicular to the line joining these two points. The tubercle centre was found to be 20 mm (. sd. 7) lateral to the centre of the medial tibial condyle. Compared with this axis, an axis perpendicular to the posterior condylar axis was internally rotated by 6° (. sd. 3). An axis based on the tibial tubercle and the tibial spines was also internally rotated by 5° (. sd. 10). Alignment of the knee when based on this anatomical axis was more reliable than either the posterior surfaces or any axis involving the tubercle which was the least reliable landmark in the region

The management of chronic osteomyelitis requires the excision of necrotic and infected material followed by the prolonged administration of antibiotics. Sequestrectomy may be required before an involucrum has formed, resulting in a longitudinal bone defect. This can be difficult to fill. Vascularised grafts are complicated by a high rate of recurrent infection and thrombosis. We have managed defects of long bones in children after sequestrectomy by the use of non-vascularised fibular grafts harvested subperiosteally and held by an intramedullary Kirschner wire. Eight children underwent this procedure. In six the tibia was involved and in one each the humerus and radius. One patient was lost to follow-up. Six grafts united at both ends within 12 weeks. The seventh developed an infected nonunion distally which united after further debridement. One patient required a further sequestrectomy which did not compromise union. We have found this to be a straightforward technique with reliable results and were able to salvage the limb in all the seven patients who were reviewed

Conventional non-steroidal anti-inflammatory drugs (NSAIDs) and newer specific cyclo-oxygenase-2 (cox-2) inhibitors are commonly used in musculoskeletal trauma and orthopaedic surgery to reduce the inflammatory response and pain. These drugs have been reported to impair bone metabolism. In reconstruction of the anterior cruciate ligament the hamstring tendons are mainly used as the graft of choice, and a prerequisite for good results is healing of the tendons in the bone tunnel. Many of these patients are routinely given NSAIDs or cox-2 inhibitors, although no studies have elucidated the effects of these drugs on tendon healing in the bone tunnel. In our study 60 female Wistar rats were randomly allocated into three groups of 20. One received parecoxib, one indometacin and one acted as a control. In all the rats the tendo-Achillis was released proximally from the calf muscles. It was then pulled through a drill hole in the distal tibia and sutured anteriorly. The rats were given parecoxib, indometacin or saline intraperitoneally twice daily for seven days. After 14 days the tendon/bone-tunnel interface was subjected to mechanical testing. Significantly lower maximum pull-out strength (p < 0.001), energy absorption (p < 0.001) and stiffness (p = 0.035) were found in rats given parecoxib and indometacin compared with the control group, most pronounced with parecoxib

Aims

Commonly performed unicompartmental knee arthroplasty (UKA) is not designed for the lateral compartment. Additionally, the anatomical medial and lateral tibial plateaus have asymmetrical geometries, with a slightly dished medial plateau and a convex lateral plateau. Therefore, this study aims to investigate the native knee kinematics with respect to the tibial insert design corresponding to the lateral femoral component.

Aims

Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction.