The "ischial limb": a landmark on anterior ultrasound scanning used to assess reduction in developmental dysplasia of the hip.

BACKGROUND: Early recognition of failure of reduction during abduction splinting in developmental dysplasia of the hip (DDH) is essential to avoid inappropriate prolonged damaging harness use. Graf ultrasound scanning (USS) is an accepted gold standard for assessing neonatal hip dysplasia but cannot verify reduction in the abducted position of a neonatal hip in a Pavlik harness. We describe a new anatomic landmark of the hip using anterior USS-the "ischial limb," correlate this to the position of the femoral head in reduced and dislocated positions, and assess the application of this in the assessment of DDH. METHODS: A porcine model was used to identify anatomic, radiologic, and ultrasonic features comparable to the human neonatal hip. A pilot clinical study was conducted of 50 neonates (11M:39F) treated for DDH in Pavlik harness, utilizing weekly anterior USS to determine the concentricity of femoral head reduction relative to the ischial limb and whether this could identify any failures to achieve reduction. RESULTS: The animal model identified an ultrasound landmark, termed the ischial limb that represents the ossification zone of the ischial contribution to the tri-radiate acetabular cartilage, and approximates to the center of the acetabulum. Anterior USS clearly demonstrated this ischial limb in clinical practice and its relation to the femoral head in all dysplastic hips (n=79). Immediate concentric reduction was observed in 11 patients, more gradual reduction over 3 weeks in 37 patients, and failure to achieve stable reduction was verified in 2 patients. The technique was reproducible in 100% of patients (n=50). Mean additional clinic time was 5 minutes per visit. CONCLUSIONS: The ischial limb, identified on anterior hip USS, delineates the position of the tri-radiate cartilage. This technique efficiently assesses hip reduction during Pavlik harness treatment and can differentiate between failure to achieve reduction or maintain a stable reduction at an earlier stage than conventional US methods. LEVEL OF EVIDENCE: Development of diagnostic criteria on basis of consecutive patients: level 2 evidence.

Teaching within the operating theater.

All surgeons within teaching hospitals share in the collective responsibility for training more junior doctors. A large proportion of training focuses around developing good clinical practice and ensuring the trainee is reaching competency. Formal structured teaching sessions aim to improve the trainee's theoretical knowledge and wider understanding. But surgical trainees must also learn how to operate. In order to do this, a more experienced surgeon must teach and supervise them in how to perform common procedures. This article discusses effective teaching within the operating theater, drawing on the author's own reflective practice. It introduces the concepts of theater prerequisites, used for assessing the suitability of theater cases for teaching, and active observation as one of the methodologies for teaching in theater.

Verification of hip reduction using anterior ultrasound scanning during Pavlik harness treatment of developmental dysplasia of the hip.

AIM: Ultrasound scanning (USS) is used for diagnosis and surveillance in developmental dysplasia of the hip (DDH). Lateral coronal scanning is performed with the hip flexed, in neutral adduction. In this position an unstable hip may dislocate, failing to demonstrate a reducible hip, leading to abandonment of harness treatment. Anterior ultrasound permits imaging of the flexed abducted hip in harness. This study evaluates the role of anterior & lateral USS in determining duration of treatment and reduction in DDH. METHOD: Between 1997 & 2010, 233 patients requiring harness treatment received lateral USS, with dislocated & dysplastic hips re-imaged fortnightly. From 2005, anterior USS was used additionally to assess reduction in harness. RESULTS: One-hundred and eighteen patients (167 hips) received lateral USS, 115 (160 hips) received both. In the lateral cohort, 103 (140 hips) were treated successfully, mean duration 66.2 days (95% CI 60.2-72.1), with 15 (26 hips) failures (15.5%), mean 30 (CI 95% 19.3-40.6). In the anterior cohort, 107 (150 hips) were treated successfully, mean 53.3 (95% CI 49.8-56.7), with 8 (10 hips) failures (6.25%), mean 35.3 (CI 95% 25.5-44.9). Children receiving an anterior USS had a shorter duration of treatment (p = 0.011) and no difference in failures (p = 0.21). CONCLUSIONS: A reduced duration of treatment for Graf 3 hips was observed. Anterior ultrasound allows earlier recognition of hips that fail to stabilize, via two observed modes of failure; failure of hip reduction and failure to stabilize after reduction.

Hip resurfacing arthroplasty in patients with varus deformity of the femoral neck-shaft angle.

Hip resurfacing arthroplasty (HRA) in patients with a varus deformity of the femoral neck-shaft angle (NSA) is associated with poorer outcomes. Our experience has not reflected this. We examined the Oxford Hip Scores (OHS), Harris Hip Scores (HHS) and outcomes of patients with varus hips against a normal cohort to ascertain any significant difference. We identified 179 patients. Measurement of the femoral neck-shaft angle was undertaken from antero-posterior radiographs pre-operatively. The mean NSA was 128.5 degrees (SD 6.3). Patients with a NSA of less than 122.2 were deemed varus and those above 134.8 valgus. These parameters were consistent with published anatomical studies. The 'varus' cohort consisted of 23 patients, mean NSA 118.7 (range 113.6-121.5), mean follow-up 49 months (range 13-74). Mean OHS and HHS were 16 and 93.5 respectively. Complications included 2 cases of trochanteric non-union, but there were no femoral neck fractures, early failures or revisions. The 'normal' cohort consisted of 125 patients, mean NSA 128 degrees, mean follow-up 41 months (range 6-76). The OHS and HSS were 18.8 and 88.9 respectively. Complications included 5 trochanteric non-unions and 1 revision due to an acetabular fracture following a fall. Statistical analysis demonstrated no statistical difference between the cohorts' OHS (p=0.583) or HHS (p=0.139). Our experience in patients with a varus femoral neck has been positive. We have not yet experienced any femoral neck fractures, which we believe is in part due to the use of an uncemented femoral component and preservation of blood supply.