Children with osteogenesis imperfecta (OI) frequently present with coxa vara (CV). Skeletal fragility, severe deformity and limited fixation options make this a challenging condition to correct surgically. Our study aimed to determine the efficacy of the Fassier technique to correct CV and determine the complication rate.

Retrospective, descriptive case series from a tertiary hospital. We retrospectively reviewed records of a cohort of eight children (four females, 12 hips) with OI (6/8 Sillence type III, 2/8 type IV) who had surgical treatment with Fassier technique for CV between 2014 and 2020.

Inclusion Criteria: All patients with CV secondary to OI treated surgically with Fassier technique.

Exclusion Criteria: Patients older than 18 years; Patients with CV treated non-operatively or by surgical technique different to Fassier technique.

Data relating to the following parameters was collected and analyzed: demographic data, pre- and postoperative neck shaft angle (NSA), complications and NSA at final follow-up.

The mean age at operation was 5.8 years (range 2–10). The mean NSA was corrected from 96.8° preoperatively to 137º postoperatively. At a mean follow-up of 38.6 months, the mean NSA was maintained at 133°, and 83% (10/12) of hips had an NSA that remained greater than 120°. There was a 42% (5/12) complication rate: three Fassier–Duval rods failed to expand after distal epiphyseal fixation was lost during growth; one Rush rod migrated through the lateral proximal femur cortex with recurrent coxa vara; and one Rush rod migrated proximally and required rod revision.

The Fassier technique effectively corrected CV in children with moderate and progressively deforming OI. The deformity correction was maintained in the short term. The complication rate was high, but mainly related to the failed expansion of the Fassier–Duval rods.

Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMDMethods: 119 patients were randomised to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. All surgeries were performed via the posterior approach with mobilization on the day of surgery. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years and compared to the unoperated contralateral femur as a control. Patient reported outcome measures of pain, function and health were also included at these corresponding follow-ups.

BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% inthe mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures.

This study demonstrated maintenance of femoral BMD in three different cementless femoral stem designs, with all achieving excellent improvements in patient reported outcomes. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship.

Background:

Tibia Vara (Blount's disease) is characterized by a growth disturbance of the posteromedial proximal tibial physis. This results in the typically complex tibial deformity of varus, procurvatum and internal tibial torsion. Knee instability is due to medial tibial joint depression and lateral ligament complex attenuation. Femoral angular and rotational deformity are associated features. Obesity often complicates management. Langenskiöld observed six stages of the disorder on X-ray (stage 6 not occurring before 9 years) and obtained good results with proximal tibial realignment osteotomy if performed before the age of 8 years. Our experience is very different.

Background:

Recurrent or late presenting Tibia Vara is a complex clinical problem. In addition to the multiplanar deformity the disorder is often accompanied by obesity. Simple re-alignment osteotomy with acute correction is effective early in the disease. Its use in recurrent or severe deformities is limited by geometric constraints (mechanical axis translation), difficult fixation and the risk of compartment syndrome. Gradual correction with external fixation devices is a well-accepted technique in these cases. It has been shown to obtain accurate correction and provides stable fixation. This allows early weight bearing which facilitate consolidation and rehabilitation. Hexapod fixators are technically less demanding than standard Ilizarov techniques. The TLHex is a relatively new hexapod fixator available in South Africa. Frame pre-assembly allows easier mounting on a limb with complex deformity. The software allows for non-orthogonal mounting, which simplifies frame-mounting assessment. Double telescoping struts allow greater strut excursion and the outside mounting of struts on the ring increases mounting options for fixation elements.

This is the first report on its use in Blount's disease.

Introduction

Coxa vara is an uncommon orthopaedic condition. Problems associated with the definition, radiological appearance, classification and surgical treatment are discussed.

Introduction

Management of the sequelae of arthritis of the hip joint has changed over time. Total joint replacement has gained popularity due to retained mobility and stability. In the high demand paediatric and adolescent population problems are encountered with longevity of the procedure. Hip arthrodesis is a useful alternative procedure that sacrifices mobility of the joint to achieve pain relief and restores function. Several surgical techniques have been described to achieve hip fusion. We describe a technique that achieves concentric bone surfaces with hip resurfacing reamers. Maximum bone is preserved to maintain leg length. Trans-articular compression is achieved with cannulated screw fixation. Subtrochanteric de-functioning osteotomy completes the procedure to protect the fusion site and control the position of the limb. Our optimal position of fusion was 30 degrees of flexion, neutral to 5 degrees of abduction and neutral to 10 degrees of external rotation.