In 2010, we published results of Ponseti versus primary posteromedial release (PMR) for congenital talipes equinovarus (CTEV) in 51 prospective patients. This study reports outcomes at a median of 15 years from original treatment. We followed 51 patients at a median of 15 years (range 13–17 years) following treatment of CTEV with either Ponseti method (25 patients; 38 feet) or PMR (26 patients; 42 feet). Thirty-eight patientsd were contacted and 33 participated in clinical review (65%), comprising patient reported outcomes, clinical examination, 3-D gait analysis and plantar pressures. Sixteen of 38 Ponseti treated feet (42%) and 20 of 42 PMR treated feet (48%) had undergone further surgery. The PMR treated feet were more likely to have osteotomies and intra- articular surgeries (16 vs 5 feet, p<0.05). Of the 33 patients reviewed with multimodal assessment, the Ponseti group demonstrated better scores on the Dimeglio (5.8 vs 7.0, p<0.05), the Disease Specific Instrument (80 vs 65.6, p<0.05), the Functional Disability Inventory (1.1 vs 5.0, p<0.05) and the AAOS Foot & Ankle Questionnaire (52.2 vs. 46.6, p < 0.05), as well as improved total sagittal ankle range of motion in gait, ankle plantarflexion range at toe off and calf power generation. The primary PMR group displayed higher lateral midfoot and forefoot pressures. Whilst numbers of repeat surgical interventions following Ponseti treatment and primary PMR were similar, the PMR treated feet had greater numbers of osteotomies and intra-articular surgeries. Outcomes were improved at a median of 15 years for functional data for the Ponseti method versus PMR, with advantages seen in the Ponseti group over several domains. This study provides the most comprehensive evaluation of outcomes close to skeletal maturity in prospective cohorts, reinforcing the Ponseti Method as the initial treatment of choice for idiopathic clubfeet
To systematically review the efficacy of split tendon transfer surgery on gait-related outcomes for children and adolescents with cerebral palsy (CP) and spastic equinovarus foot deformity. Five databases (CENTRAL, CINAHL, PubMed, Embase, Web of Science) were systematically screened for studies investigating split tibialis anterior or split tibialis posterior tendon transfer for spastic equinovarus foot deformity, with gait-related outcomes (published pre-September 2022). Study quality and evidence were assessed using the Methodological Index for Non-Randomized Studies, the Risk of Bias In Non-Randomized Studies of Interventions, and the Grading of Recommendations Assessment, Development and Evaluation.Aims
Methods
Cerebral palsy (CP) is a neural condition that impacts and impairs the musculoskeletal system. Skeletal muscles, particularly in the lower limb, have previously been shown to be significantly reduced in volume in CP compared to typical controls. Muscle volume is a gross measure, however, and does not capture shape characteristics which—if quantified—could offer a robust and novel assessment of how this condition impacts skeletal muscle form and function in CP. In this study, we used mathematical shape modelling to quantify not just size, but also the shape, of soleus muscles in CP and typically developing (TD) cohorts to explore this question. Shape modelling is a mathematical technique used previously for bones, organs, and tumours. We obtained segmented muscle data from prior MRI studies in CP. We generated shape models of CP and TD cohorts and used our shape models to assess similarities and differences between the cohorts, and we statistically analysed shape differences. The shape models revealed similar principal components (PCs), i.e. the defining mathematical features of each shape, yet showed greater shape variability within the CP cohort. The model revealed a distinct feature (a superior –> inferior shift of the broad central region), indicating the model could identify muscular features that were not apparent with direct observation. Two PCs dominated the differences between CP and TD cohorts: size and aspect ratio (thinness) of the muscle. The distinct appearance characteristic in the CP model correspond to specific muscle impairments in CP to be discussed further. Overall, children with CP had smaller muscles that also tended to be long, thin, and narrow. Shape modelling captures shape features quantitatively, which indicate the ways that muscles are being impacted in CP. In the future, we hope to tailor this technique toward informing diagnosis and treatments in CP.
Dislocated hip hemiarthroplasties (HA) are associated with a 45% revision rate and 40% mortality rate. Implant selection for HA operations vary with no universally accepted implant choice. The WHiTE3 trial suggested older designs such as the Thompson has equitable outcomes to more modern and expensive implants such as the Exeter V40+Unitrax. Our multi-centre consecutive series of NOFs patients treated with HA assesses the impact of surgical and patient factors on dislocation risk. Medical and radiographic records for patients treated between 1stJanuary 2009 and 30thSeptember 2017 with a HA at three acute hospitals were reviewed. Implant and dislocation data were recorded. Patient demographics, comorbidities and operation details were extracted from the medical records and NHFD. Patients were excluded if there were no postoperative radiographs or when HA had been performed as a revision procedure.Introduction
Methods
Adverse reaction to metal debris (ARMD) is well recognised as a complication of large head metal on metal total hip replacement (THR) leading to pain, bone and tissue loss and the need for revision surgery. An emerging problem of trunnionosis in metal on polyethylene total hip replacements leading to ARMD has been reported in a few cases. Increased metal ion levels have been reported in THR's with a titanium stem and a cobalt chrome head such as the Accolade-Trident THR (Stryker). We present 3 cases of ARMD with Accloade-Trident THR's with 36mm cobalt chrome head and a polyethylene liner. Metal ion levels were elevated in all three patients (cobalt 10.3 – 161nmol/l). Intraoperative tissue samples were negative for infection and inflammatory markers were normal. Abnormal fluid collections were seen in all three cases and bone loss was severe in one patient leading to a proximal femoral replacement. Histology demonstrated either a non-specific inflammatory reaction in a case which presented early or a granulomatous reaction in a more advanced case suggesting a local foreign body reaction. All patients had improved symptoms post-operatively. 1 patient who had staged bilateral Accolade-Trident THR's required revision of both THR's. ARMD in metal on polyethylene THR's with a titanium stem represents a potential emerging problem. Further studies are required to assess whether these occurrences are rare or represent the tip of an iceberg.
Prosthetic joint infections (PJIs) generate significant clinical and socio-economic pressures on the health service. Recent advances in the diagnosis of PJIs, with biomarkers and sonification have aided delineation of PJIs from aseptic processes. However these investigations are not widely available and expensive. Interface membrane histology has been shown to be superior to pseudocapsule histology; we therefore sought to ascertain the diagnostic benefit of deep canal sample microbiology in conjunction with standard pseudocapsule sampling. We performed a prospective study over a 20-month period as part of new multi-disciplinary approach to the management of suspected PJIs. 22 patients underwent 26 procedures at our institution where intra-operative deep canal samples were obtained concurrent to conventional pseudocapsule samples. These samples were cultured and analysed following our standardised microbiological methodology.Introduction
Patients/Materials & Methods
Human mesenchymal stem cells (hMSCs) have the capacity to differentiate into adipocytes, chondrocytes, or osteoblasts, and are an exciting tool to be used in regenerative medicine and surgery. By manipulating the surface structure and physical properties of a biomaterial on which hMSCs can be incorporated, the biological response of these cells at the implant site can be controlled. Whilst both topography and surface stiffness are known to influence differentiation of hMSC's, little is understood of the molecular mechanisms that underpin these responses. In this study we use immunofluorescence and confocal microscopy techniques to assess the change in both the abundance and the distribution of H3K9me2 or H3K9ac patterns in hMSCs cultured on materials with controlled topography and stiffness, under basal and osteogenic conditions. These data demonstrate that levels and localisation of both H3K9me2 and H3K9ac alter in hMSCs cultured on the different substrates and that these surfaces dictate the response to osteogenic stimuli, suggesting that the control of cytoskeletal structure can be linked to chromatin activity. This regulation of histone modification by MSC interaction with the surrounding scaffold provides not only a mechanistic link to the control of cell fate but also the opportunity to design biomaterials that better influence cell activity.
We report our retrospective multicentre experience of managing periprosthetic knee fractures using locking plates, cemented nails and distal femoral prosthesis. The Aim of this study is to analyze the practicality of management of these injuries using modern methods of fixation or salvation. 62 patients presented to 3 centres between 2003 and 2010. After implementation of inclusion criteria, clinical, radiological and functional outcomes were evaluated in 54 patients, with a minimum follow-up of 6 months. 34 patients were treated with locking plates (10 males, 24 female; mean age 76), 16 with cemented/locking nails (4 males, 12 females; mean age 84.5), and 4 with distal femoral replacement prosthesis (2 males, 2 females; mean age 79). Locking plates which were used with a minimally invasive pattern produced the best outcomes in our study. A statistical significance of p value of less than 0.01 was found in union time between patients operated on with an open technique (6.69±2.69 months) and those operated on with a minimally invasive technique (3.6±0.91 months). Nailing with augmented cement is a useful technique in patients who are not suitable for challenging surgery & rehabilitation programmes. There was a significant difference in mean time to functional weight bearing (p< 0.01) between the plate group (4.79±2.6 months) and the nail group (2.63±0.5 months). Post-operative range of motion was also better for nails (106.36±14.33O flexion) compared to plates (93.24±26.8O), a result that approached significance (p=0.065). We recommend minimal invasive plating in uncompromised physiological conditions, as an ideal method of fracture fixation in view of statistically significant union rates. Cemented nailing is recommended in patients where early rehabilitation is essential. Distal Femoral prosthesis replacement is a useful salvage method.
Unrecognized pin penetrance in the treatment of SCFE by percutaneous pinning has been shown to be under-reported with serious long-term sequelae. The purpose of this study was to use post-operative CT to determine the true position of the screw tip when compared to intra-operative x-rays. Twenty-four patients were offered post operative CT scans in the acute and clinic setting. Intra-operative plain films (AP and lateral) were compared to post operative CT scans (coronal and axial) to determine
the distance of the screw tip from the particular surface of the hip joint, the number of screw threads across the physis and the three dimensional placement of the screw tip in the femoral head relative to the physis. The positions of a total of 38 screws were measured. Plain x-rays where shown to consistently underestimate the distance to the articular surface. There were significant differences in the distance to the articular surface in the AP (5.5 mm) vs. coronal (3.4 mm) and lateral (4.7 mm) and vs. axial CT (4.1 mm) planes (p <
0.01). The average number of screw threads across the articular surface on the lateral x-ray was 6.7 vs. 8.1 in the coronal CT (p<
0.05). Four of the screws were shown to penetrate the joint surface in CT not shown on plain film. This study has found that CT scans show screws are closer to the joint surface in the axial and coronal plane on CT when compared to plain x-ray in the AP and lateral plane. CT scans also show that there are more screw threads across the epiphysis than shown on plain x-ray. Placement of the screw within specific quadrants of the femoral head was found to be similar on CT and x-ray. CT scans identified pin penetrance not seen on intra-operative images.
Cannulated screw fixation is currently the treatment of choice for slipped capital femoral epiphyses (SCFE). A SCFE module of the Bonedoc simulator was created in order to test the ability of advanced trainees to place the screw in the correct position, and the practicality of using the simulator within the orthopaedic surgery training curriculum. Bonedoc (University of Auckland) is a virtual reality simulator of image guided orthopaedic operations Forty two advanced trainees operated on the same virtual SCFE during a training weekend. The trainees had 25 minutes to become familiar with the simulator and complete the operative case. The trainees performed all tasks relevant to the operation. At the operation’s conclusion the trainees self-assessed their performance. Subsequently the simulator provided surgically relevant objective feedback on aspects such as exact position of the screw, misplaced attempts and the number of x-rays. The results were analysed using SAS (SAS Institute, USA) in subgroups based on year on the scheme, as well as correlated within each operation. There was no difference in the accuracy with which the virtual slipped capital femoral epiphysis was pinned by trainees in different years in the training programme. However, 26 of the 39 of the virtual screws were placed in the superior direction. There was no correlation between number of X-ray images taken and final accuracy of screw placement. The number of misplaced drill holes was correlated both with number of X-ray images taken (p<
0.01) and operative time (p<
0.01) but not with final accuracy of the screw. An increase in misplaced attempts was correlated with angulation errors in the anterior plane (p<
0.01). There was no correlation between the trainees’ self assessment and any of the measured variables. The Bonedoc simulator provides a means to test trainees on technical aspects of a surgical procedure. It provides objective results, which can mimic real world outcomes. In addition, the ability to test all trainees on the same virtual operative case allows standardisation of assessment. All trainees completed the task to a similar level of accuracy, which may reflect the overall skill level in advanced trainees within the New Zealand. However, many trainees placed the screw in the superior portion of the femoral head, which is thought to increase the risk of avascular necrosis
Cerebral palsy (CP) results from an injury to the immature brain; and it leads to progressive musculoskeletal (MS) impairment in most affected patients. Orthopaedic surgery involving muscle-tendon lengthening is a method for managing short muscles in CP patients. Knowledge of muscle length prior to surgery is beneficial to surgical success. However, using common assessment methods like 3D gait analysis or physical examination, accurate pre-surgery estimation of muscle lengths during walking is difficult. Computer models of the lower limbs, which provide more insight into muscle functioning during walking, have become increasingly important within the research field of CP. MS models are commonly driven by joint kinematics from clinical gait analysis. The most often used MS model in CP related research is based on the geometry of an adult human man with muscles modelled as line segments. This approach might be reasonable for small muscles with well-defined paths; however, for long muscles with multiple attachment points and curved paths, a more realistic 3D muscle model is required. The aim of this study is the development of a clinical assessment tool for CP patients by incorporating kinematic data from gait analysis into a 3D finite-element MS model of the lower limbs. Ethical approval has been obtained to develop subject-specific MS models of 12 children with CP and 12 control children (age 8 – 12 years) based on magnetic resonance images. Kinematic data from 3D gait analysis is used as input data to transform the bony structures. Soft-tissue muscle deformation is modelled according to a variant of free-form deformation called the Host-Mesh Fitting Technique. So far, MS models of the lower limbs of three control children and of one child with CP were developed. The resulting muscle length changes during walking agree reasonably well with published data. The proposed modelling approach together with the library of 24 MS models will enable us to develop a powerful tool to investigate gait of children with CP.
The aim of this study was to investigate upper limb botulinum toxin A (BTX-A) injections in children with spastic hemiplegia. Ten children with hemiplegia, aged 10–17 years, received upper limb BTX-A injections and 6 weeks therapy. BTX-A was injected using EMG guidance into elbow and wrist flexors, and forearm pronators (dose 1–2 units/kg body wt (Botox®) per muscle). Follow-up assessments continued to 24 weeks post BTX-A. Outcome measures included three-dimensional (3-D) upper limb analysis of functional tasks, Melbourne Assessment; passive range of motion (PROM), and muscle tone. There were no serious adverse effects. Elbow flexor muscle tone was reduced to 12 weeks post BTX-A (p <
0.05). Mean passive elbow supination increased by 19 degrees (not significant, p= 0.3). Pre-injection 3-D analysis showed that, compared to controls, children with hemiplegia were slower at performing upper limb reaching tasks, using less elbow extension and supination, and utilising increased compensatory trunk forward flexion. Post BTX-A, the time to complete upper limb tasks did not change (p>
0.15). However, at least six subjects had increased elbow extension (average 17 degrees) and decreased trunk forward flexion (average 16 degrees) during upper limb reaching tasks. Five subjects improved their Melbourne Assessment score by 5% or greater. Decreased tone and individual improvements in upper limb functional tasks were seen post BTX-A and therapy. However deficits in timing of upper limb movements did not change post BTX-A.
We studied the results of multi-level surgical intervention for children with cerebral palsy. Thirty patients, aged 7–16 years, with spastic diplegia (n=20), or spastic hemiplegia (n=10) were studied prospectively by gait analysis. Multilevel surgery included a combination of psoas lengthening, medial hamstring lengthening, rectus femoris transfer and gastrocnemius lengthening +/− foot surgery or femoral derotation osteotomies. Gait analyses were carried out pre-op and at 6 and 24 months post-op. Children with spastic diplegia increased their walking velocity by an average of 20% at two years (p<
0.05). Mean stride length increased from 89cm pre-op to 102cm at two years (p<
0.05) with similar improvements in both groups of children. Maximum knee extension in stance improved from an average 17.5 degrees flexion pre-operatively to an average 5 degrees flexion postoperatively (p<
0.05). Peak knee flexion in swing was maintained and the timing improved. Peak ankle dorsiflexion in stance was unchanged following surgery but the timing of peak ankle dorsiflexion was normalised to late stance (from 24% of cycle pre-operatively to 48% of cycle post-operatively (norm = 48%). Average maximum hip extension in stance did not change. The mean anterior pelvic tilt did not change post-operatively. However, a number of children with spastic diplegia had increased anterior pelvic tilt post-operatively. These results are similar to those reported internationally, with most improvement seen distally at the knee and ankle and less improvement at the hip. Increased anterior pelvic tilt was seen as a consequence of hamstring lengthening in some more involved patients.
There is increasing pressure to develop virtual reality surgical simulation that can be used in surgical training. However, little is known of the attitudes of the surgical community towards such simulation, and which aspects of simulation are most important. A postal survey on attitudes to surgical simulation was sent to all New Zealand orthopaedic surgeons and advanced trainees. This comprised 44 questions in ten sections, using either a visual analogue scale (0 to 10) or free text box replies. Results were analysed for two sub-groups; surgeons qualified before 1990 and those qualified in or after 1990 or still in training. Of 208 possible responses, 142 were received, a response rate of 68%. Only 4 respondents had tried a surgical based simulator. Earlier qualified surgeons were more likely to agree that simulation was an effective way to practice surgical procedures, median score 7.7 versus 5.6 (p=0.03). Both groups thought the most important task for simulation was practicing angulation/spatial orientation (median score 8.4/10), while a realistic view of the operation was the most important requirement (median score 9/10). Both groups were unconvinced that simulation would impact on their practice in the next five years, with this statement being scored lower by later qualified surgeons, median score 2.4 versus 4.1 (p=0.04). Orthopaedic surgeons in New Zealand are supportive of surgical simulation but do not expect simulation to have an impact in the near future. Intriguingly, later qualified surgeons and trainees are more sceptical than their earlier qualified colleagues.
Femoral fractures are a common injury in the paediatric population. The purpose of this study was to audit the cost and early outcomes of femur fractures treated at the Starship Childrens Hospital Forty-eight femur fractures treated between January 1998 and December 2002 were reviewed. 25 fractures were treated by application of an early hip spica, 12 by IM nails and 11 by other methods. Children treated by early hip spica averaged 3.8 years in age. They went to theatre an average of 29.1 hours after admission and had an average length of stay of 3.8 days. In the 30 days after discharge, five patients were readmitted for loss of fracture position. Children treated with IM elastic nails averaged 9.5 years and went to theatre on average 35.1 hours after admission. Their length of stay averaged 8.3 days. Complications in hospital included return to theatre to shorten a wire (1 patient), remanipulation and application of a hip spica (2 patients) and difficulty mobilizing (1 patient). In the first 30 days after discharge, two patients required readmission for further surgery due to prominence of the wire. Children treated with external fixator (7), femoral rod (1) or crossed k-wires (3) averaged 8.7 years in age. They went to theatre on average 58 hours after injury and had an average length of stay of 24 days. Two patients were readmitted with superficial pin-site infections. Most femur fractures are being operated on the next day, however surgery is delayed in some patients. The readmission rate in the first 30 days is significant and is not reduced by operative fixation. Cost containment should focus on ways to reduce the early readmission rate.
Reimers’ hip migration percentage is commonly used to document the extent of subluxation of the hip in children with spasticity. In this study, two measurers, with six months paediatric orthopaedic experience, measured the migration percentage on 44 pelvic radiographs of children with cerebral palsy, aged between two and eight years. Unknown to the measurers, each radiograph was duplicated, giving 22 non-identical radiographs (44 hips) which were measured twice at time 0 and twice six weeks later. The intra-measurer, intra-sessional absolute differences between the first and second measurements ranged from 0% to 23%, with median values of 2.5% to 3.6%. The intra-sessional median absolute differences were not statistically different between the two measurers and measuring sessions (p = 0.42, Kruskal-Wallis test). The inter-sessional absolute differences for measurements made by the same measurers ranged from 0% to 18% with a median absolute difference of 1.7% to 3.2%. Overall, only 5% of the intra-measurer measurement differences, within and between sessions, were above 13%. Repeated measurements by one measurer over time must, therefore, vary by more than 13% in order to be 95% confident of a true change. The inter-measurer error was higher with median absolute differences between the two measurers’ measurements of the same hip of 3.25% to 5% (0% to 26%) and a 95th upper confidence interval of 21% to 23%. Averaging the four separate measurements over the two sessions reduced the inter-measurer error to a median absolute difference of 2.8%, but did not improve the 95th upper confidence interval, which measured 22.4%. Such inter-measurer errors may be clinically unacceptable.
The purpose of the study was to evaluate the functional outcome of different limb salvage procedures for osteosarcoma about the knee. A selection of patients who have undergone limb salvage procedures for osteosarcoma about the knee were invited to join the study. Medical and operation notes were reviewed along with recent radiographs of the involved limb. Patients completed the Musculoskeletal Tumour Society functional questionnaire and underwent a gait analysis assessing walking and running. Most patients had stage 2B osteosarcoma involving either the proximal tibia or distal femur. Limb salvage procedures included arthrodesis, allograft reconstruction, endoprosthesis and rotationplasty. All patients scored highly (>
70 %) on the MSTS questionnaire except the arthrodesis that scored 57 %. The gait analysis revealed some subtle changes with a quadriceps-sparing gait in the endoprosthesis, mild foot drop in the proximal tibial allograft and a lateral lean of the trunk over the ipsilateral limb in the rotationplasty. The arthrodesis had an obvious straight leg gait with subtle pelvic hiking to assist foot clearance. While analysis of walking was close to normal most patients were unable to obtain a double float and run. This study shows that limb salvage procedures tailored to each individual case can result in an excellent functional outcome with close to normal gait and high MSTS scores.