Mark S. Gaston

Transverse plane rotation of the foot and transverse hip and pelvic kinematics in diplegic cerebral palsy

External rotation of the foot associated with mid-foot break is a commonly observed gait abnormality in diplegic CP patients. Previous studies have shown a correlation between equinus and internal hip rotation in hemiplegic patients. This study aimed to determine if there was a correlation between the amount of transverse plane rotation in diplegic CP patients using kinematic data from standardised gait analysis. Lower limb data of 134 ambulant children with diplegic CP was analysed retrospectively determining the maximum change in foot, hip and pelvis rotation during loading response. Highly significant negative correlations (P=<0.001) were found between foot and hip movements and foot and pelvic movements. Equinus at initial contact diminished the foot:hip correlation while it enhanced the foot:pelvic correlation. There was less external rotation of the foot in equinus patients (P=0.012) and more external rotation of the pelvis in the equinus group (P=<0.001). This data reveal a correlation between transverse plane rotation at foot level to that at the hip and pelvis. The likely biomechanical explanation is relatively excessive transverse external rotation of the foot due to abnormalities such as mid-foot break. When under load, where the foot is fixed to the floor, internal rotation of the entire leg occurs. This is due to lever arm disease as a result of the relatively shortened foot and inefficiency of the plantar-flexion knee-extension couple. Equinus modulates the effect. When treating such patients, lever arm deformities at all levels must be considered to result in the best outcome and prevent recurrences.

Microbiological characteristics of acute osteoarticular infections in children

This study aimed to describe the microbiological characteristics of acute septic arthritis (SA) and osteomyelitis (OM) in children. Cases of children (0-15 years) with SA/OM were identified through a retrospective search of hospital discharge codes over a six-year period. In addition, a systematic literature search and meta-analysis of studies reporting culture results of children with SA/OM was performed. In our retrospective chart review, we identified 65 cases of OM and 46 cases of SA. The most frequently cultured organisms in both conditions were Gram-positive cocci, primarily Staphylococcus aureus. On admission, most patients had a normal white blood cell count (WCC) but elevated C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR). Bacteraemia was associated with a longer mean length of hospitalization for both infections. Considering our results and the meta-analysis, we found low rates of culture-positivity in cases of clinically confirmed infection. In SA, articular fluid was culture-positive in 42.49% [95% confidence interval (CI) 28.39-57.23]. In OM, intra-operative samples were culture-positive in 52.65% (95% CI 30.54-74.22). Bacteraemia was detected in 23.91% (95% CI 8.40-44.24) of children with SA and 21.48% (95% CI 10.89-34.47) with OM. Despite appropriate sampling, a positive microbiological diagnosis is often lacking in paediatric acute osteoarticular infection using standard culture-based methods. This highlights the need for validation and use of more sensitive diagnostic methods, such as PCR.

Distal femoral osteotomy using the LCP pediatric condylar 90-degree plate in patients with neuromuscular disorders.

Background: In patients with cerebral palsy and other neuromuscular disorders, correction of a fixed knee flexion deformity is thought to be crucial for the improvement of gait. The distal femoral extension osteotomy (DFO) is one method to achieve this goal. The standard implant for fixation of the 2 fragments in DFO is the conventional AO blade plate. The aim of this study was to report the outcome of using the new LCP Pediatric Condylar 90-Degree Plate for DFO. Methods: Thirty-eight patients undergoing 63 DFOs were included. The mean age was 16.3±4.4 years (range, 4 to 27 y) at the time of surgery. Thirty-two patients had a diagnosis of cerebral palsy and 6 patients had other neuromuscular disorders including myelomeningocoele and arthrogryposis. Thirteen patients had unilateral procedures and 25 had bilateral procedures. Results: The mean duration of the surgical intervention was 67.9±26.5 minutes (range, 30 to 180 min) and the mean blood loss was 100.0±42.1 mL (range, 50 to 250 mL). In 84% of the cases, large-fragment (5.0 mm) implants were used. The mean extension correction in 84% of the patients (n=53) was 22.8±10.3 degrees (range, 5 to 50 degrees). In this series, there were 2 complications in 63 osteotomies (3%). Radiologic follow-up of the cohort was until the time of plate removal (14.2±4.3 mo; range, 6 to 26 mo). Three months after the index operation, all osteotomies were radiologically consolidated. At this time and at plate removal, there were no malunions or nonunions in this cohort. Clinical follow-up of the cohort was performed until the end of the study (mean 35.5±6.7 mo; range, 22 to 46 mo). At the end of the study, 59 plates (94%) had been removed. Conclusions: The new LCP Pediatric Condylar 90-Degree Plate provides stable and safe fixation of distal femoral correction osteotomies in patients with neuromuscular disorders. Level of Evidence: Level IV.

Bioabsorbable lag screw fixation of knee osteochondritis dissecans in the skeletally immature

Osteochondritis dissecans (OCD) of the knee in children is associated with more morbidity than previously recognized. Sixteen knees in 13 children with symptomatic OCD lesions in the knee diagnosed with MRI underwent arthroscopic fixation using polylactide biodegradable lag screws, after failing a minimum of 6 months conservative treatment. The mean age was 12.3 years; 14 lesions were in the medial condyle, two in the lateral condyle, and the mean area was 244 mm2. Early physiotherapy was prescribed with no period of immobilization and the patients were followed for a mean of 27 months. One patient, who required a concomitant meniscal repair, developed a transient neurapraxia of the peroneal nerve but went on to full recovery. All patients but this one had returned to sport at 4-month follow-up. There was significant improvement in the knee function scores and all patients reported their knees as improved or much improved. We propose that simple arthroscopic fixation of OCD with SmartScrews is an effective treatment in the pediatric population leading to a rapid recovery of premorbid function.

A cohort study of tibialis anterior tendon shortening in combination with calf muscle lengthening in spastic equinus in cerebral palsy

The aim of this study was to evaluate the outcome of combined tibialis anterior tendon shortening (TATS) and calf muscle-tendon lengthening (CMTL) in spastic equinus. Prospectively collected data was analysed in 26 patients with hemiplegic (n=13) and diplegic (n=13) cerebral palsy (CP) (GMFCS level I or II, 14 males, 12 females, age range 10-35 years; mean 16.8 years). All patients had pre-operative 3D gait analysis and a further analysis at a mean of 17.1 months (±5.6months) after surgery. None was lost to follow-up. Twenty-eight combined TATS and CMTL were undertaken and 19 patients had additional synchronous multilevel surgery. At follow-up 79% of patients had improved foot positioning at initial contact, whilst 68% reported improved fitting or reduced requirement of orthotic support. Statistically significant improvements were seen in the Movement Analysis Profile for ankle dorsi-/plantarflexion (4.15°, p=0.032), maximum ankle dorsiflexion during swing phase (11.68°, p<0.001), and Edinburgh Visual Gait Score (EVGS) (4.85, p=0.014). Diplegic patients had a greater improvement in the EVGS than hemiplegics (6.27 -vs- 2.21, p=0.024). The originators of combined TATS and CMTL showed that it improved foot positioning during gait. The present study has independently confirmed favourable outcomes in a similar patient population and added additional outcome measures, the EVGS, foot positioning at initial contact, and maximum ankle dorsiflexion during swing phase. Study limitations include short term follow-up in a heterogeneous population and that 19 patients had additional surgery. TATS combined with CMTL is a recommended option for spastic equinus in ambulatory patients with CP.

Temporary hemiepiphysiodesis of the distal medial femur: MPFL in danger.

IntroductionTemporary hemiepiphysiodesis (TH) with plate fixation is a well-accepted and common treatment for correcting leg malalignment in skeletally immature patients. The purpose of this study was to investigate any soft tissue damage caused during TH at the distal medial femur with a plate and two screws. We hypothesized that correct plate placement can affect the integrity of the medial stabilizing structures of the knee, especially the medial patellofemoral ligament (MPFL), the medial collateral ligament (MCL) or result in arthrotomy of the knee joint itself.Materials and methodsIn eight cadaveric knees of five adult humans a TH was performed with a plate and two cancellous screws at the distal medial femur using a standardized surgical technique. Subsequently the medial capsular and ligamentous structures were systematically exposed and assessed. Capsular and synovial tissue was also inspected for impingement by the plate or screws.ResultsIn all knees the MPFL was present. In two specimens the MPFL was intact and the plate was lying over the dorsal part of the MPFL close to the MCL. The MPFL was completely cut in two cases in the central part of the ligament. In four cases the MPFL was partially dissected or perforated by a screw and fixed to the femur by the plate. The MCL was intact and not impinged by the implant in any case. In total four of eight knees the capsule was transected or perforated by a screw or by a part of the plate, resulting in intraarticular implant placement.ConclusionsStandard plate placement during TH on the distal medial femur frequently leads to damage to the MPFL, impingement of the MPFL, the capsular and synovial tissues or exposure of the knee joint.

Massive osteochondritis of the lateral femoral condyle associated with discoid meniscus: management with meniscoplasty, rim stabilization and bioabsorbable screw fixation.

Discoid menisci without tears and before surgical intervention may be an aetiological factor in the development of osteochondritis dissecans (OCD). We present the case of a massive OCD lesion in the lateral femoral condyle of a 12-year-old boy who presented with relatively few symptoms despite the size of the lesion. This was treated with meniscoplasty and rim stabilization, which has become established as the gold standard treatment for symptomatic discoid menisci. This was combined with bioabsorbable screw fixation of the OCD lesion, resulting in rapid resolution of symptoms and a return to normal magnetic resonance image appearances after 6 months. It is likely that instability of discoid menisci is a key causal component when present concurrently with OCD lesions. Therefore, stabilization of this is required as well as saucerization of the meniscus. OCD lesions which are of a sufficient size such that if they became unstable or dislocated would result in a significant defect should also be stabilized. We believe that bioabsorbable screw fixation presents a good solution for fixation in these cases and this combination of treatment should result in a satisfactory outcome.

Supracondylar osteotomy of the paediatric femur using the locking compression plate: a refined surgical technique

Locking compression plates (LCP) have been developed for paediatric patients, and these provide safe bone fixation and allow for immediate weight-bearing. These plates are becoming increasingly popular and are proving to especially useful for the treatment of proximal and distal (supracondylar) femoral osteotomies. They are thought to provide better grip in osteoporotic bone. The technique has been described in the provider’s manual as well as recently by Joeris et al. (Int Orthop 2012: 36:2299–2306). The LCP system offers optimal stability after the final fixation, but temporary fixation using the originally described method is unstable, and we consider the medialisation instrument unsatisfactory as it has very small contact area with the lateral aspect of the femur and does not provide sound rotational control. For this reason we have developed a technique whereby temporary, stable fixation using fine K-wires can be attained for the proximal, diaphyseal fragment, following sound fixation with locking screws of the distal fragment. This procedure allows for full clinical (including rotation) and radiographic assessment intraoperatively, as well as fine adjustment in all three planes. This modification enables optimal correction before the final fixation and avoids unnecessary, large drill holes which may otherwise act as dangerous tress risers, endangering stability and weight-bearing. Here we describe a refined technique of the supracondylar femoral osteotomy using the paediatric LCP Condylar Plate.

Using a goal attainment scale in the evaluation of outcomes in patients with diplegic cerebral palsy

A goal attainment scale (GAS) was used to evaluate outcomes of surgical and non-surgical interventions to improve gait in 45 children with diplegic cerebral palsy. Personal goals were recorded during pre-intervention gait analysis in two groups. Twenty children underwent orthopaedic surgery (Group 1) and 25 children received a non-operative intervention (Group 2). Children and/or their carers were contacted post-intervention by telephone to complete a GAS questionnaire, rating the achievement of goals on a 5-point scale. The goals were similar in both groups. The composite GAS was transformed into a standardised measure (T-score) for each patient. Both groups on average achieved their goals (mean T-score for Group 2 was 56.3, versus 47.1 for Group 1). The difference between these two means was significant (p=0.010). Additionally, 16 children had undergone a follow-up gait analysis during the study period, but the relationship between their Gait Profile Score and GAS was not statistically significant. Both surgical and non-surgical interventions enabled children to achieve their goals, although Group 1 reported higher achievements. The GAS reflects patients/parents/carers aspirations and may be as relevant as post-intervention kinematic or kinetic outcomes.

Treatment of late-presenting Monteggia variant with an isolated, simple flexion ulnar osteotomy.

Radial head dislocation in children is usually associated with complete elbow dislocation or occurs as a part of a Monteggia injury. In patients without an obvious fracture of the ulna, recognizing that plastic deformation of the ulna leads to pathological bowing is a key concept in the management of this injury. Although good results have been published using osteotomy of the ulna to maintain stability after open reduction, we hypothesize that ulnar osteotomy alone may be enough to enable stable enlocation of an irreducible radial head in patients who are identified early. We present two cases of irreducible radial head dislocation, treated with ulnar osteotomy and closed radial head reduction. Both osteotomies united and both patients had an excellent functional outcome with the absence of pain or deformity and early return to function. We explain the surgical technique and compare the outcomes with alternative surgical treatments.