The effect of obesity and increasing age on operative time and length of stay in primary hip and knee arthroplasty.

We retrospectively reviewed 589 patients undergoing lower-limb arthroplasty, recording age, body mass index (BMI) and co-morbidities. The effect of these on operative duration and length of stay (LOS) was analysed. For a 1 point increase in BMI we expect LOS to increase by a factor of 2.9% and mean theatre time to increase by 1.46minutes. For a 1-year increase in age, we expect LOS to increase by a factor of 1.2%. We have calculated the extra financial costs associated. The current reimbursement system underestimates the financial impact of BMI and age. The results have been used to produce a chart that allows prediction of LOS following lower limb arthroplasty based on BMI and age. These data are of use in planning operating lists.

The biomechanical effect of notch size, notch location, and femur orientation on hip resurfacing failure.

For hip resurfacing, this is the first biomechanical study to assess anterior and posterior femoral neck notching and femur flexion and extension. Forty-seven artificial femurs were implanted with the Birmingham hip resurfacing (BHR) using a range of notch sizes (0, 2, and 5 mm), notch locations (superior, anterior, and posterior), and femur orientations (neutral stance, flexion, and extension). Implant preparation was done using imageless computer navigation, and mechanical tests measured stiffness and strength. For notch size and location, in neutral stance the unnotched group had 1.9 times greater strength than the 5-mm superior notch group (4539 N versus 2423 N, p=0.047), and the 5-mm anterior notch group had 1.6 times greater strength than the 5-mm superior notch group, yielding a borderline statistical difference (3988 N versus 2423 N, p = 0.056). For femur orientation, in the presence of a 5-mm anterior notch, femurs in neutral stance had 2.2 times greater stiffness than femurs in 25° flexion (1542 N/mm versus 696 N/mm, p = 0.000). Similarly, in the presence of a 5-mm posterior notch, femurs in neutral stance had 2.8 times greater stiffness than femurs in 25° extension (1637 N/mm versus 575 N/mm, p = 0.000). No other statistical differences were noted. All femurs failed through the neck. The results have implications for BHR surgical techniques and recommended patient activities.

Computer navigation vs extramedullary guide for sagittal alignment of tibial components: radiographic study and meta-analysis.

Sagittal alignment of tibial components using computer navigation was compared with conventional methods. A radiologic study was performed using 110 total knee arthroplasties from 3 groups: computer navigation, cutting block with extramedullary guide, and manual tilt of extramedullary guide. Posterior tibial slopes were measured from radiographs and compared using statistical methods. The cutting block method was the most accurate, and computer navigation was the most precise. The manual tilt group had the greatest variance, significantly greater than computer navigation. There was no significant difference between groups with respect to the percentage of knees with posterior slope within 3° of the desired slope. Meta-analysis of 10 studies found no reduction in outliers with computer navigation. Computer navigation offers greatest precision but does not reduce the number of outliers.

Complications of closing wedge high tibial osteotomy.

Closing wedge high tibial osteotomy is a common, effective and well-established procedure to treat unicompartment osteoarthrosis of the knee. It is, however, not without its complications. This article will discuss some of these complications and present an overview of the current literature. It will examine current thoughts on aetiology, techniques to try to avoid, and methods of treatment of these complications.

Complication rate after operative treatment of paediatric femoral neck fractures.

Paediatric fractured neck of femur injuries is rare and historically has high complication rates postoperatively. We present results from the Birmingham Children's Hospital. Fifteen displaced femoral neck fractures were identified in 14 children over a 10-year period (1997-2006). Mean age at the time of injury was 10 years (range 6-14 years). Mean follow-up was 31 months (range 6-110 months). Anatomical reduction and internal fixation was performed in all cases. Two fractures were classified as Delbet's type-I (13.3%), four type-II (26.7%), six type-III (40%) and three type-IV fractures (20%). Eleven patients were operated on within 24 h (range 4-19 h) and four after 24 h (range 2-11 days). The rate of avascular necrosis was 6.7% overall and 10% excluding pathological fractures. The rate of premature physeal closure was 33.3% overall and 40% excluding pathological fractures. Ninety-three percent of the total study population had a good result according to the Ratliff scoring system. There were no nonunions. One patient had a poor result with avascular necrosis and collapse.

Intermediate results of Buechel Pappas unconstrained uncemented total ankle replacement for osteoarthritis.

We present the functional and radiological results after implantation of thirty five uncemented Buechel Pappas total ankle replacements by an independent surgeon. All consecutive uncemented Buechel Pappas total ankle replacements were performed by the senior author (MSA) between 1990 and 2005. All ankle replacements were performed for osteoarthritis. The patients were assessed clinically and radiologically. The average follow-up period is five years. Nine female patients and 25 male patients with an average age of 69(58-84) were enrolled. One patient died before follow-up. Ninety seven percent of patients were happy with their operation and ninety seven percent thought it was successful. Sixty six percent of patients had no, or occasional pain. All patients were mobile and forty five percent of patients required no walking aids. Only three percent of patients required two walking aids. The American Orthopaedic Foot and Ankle Society Score was 73.3(54-100) at follow-up, compared to 34.6(20-56) pre-operatively (p < 0.001). One prosthesis was revised. Two fractured medial malleoli occurred and no deep infections were noted. Buechel Pappas Uncemented Total Ankle replacement, performed by an independent surgeon, can give intermediate results comparable to data published by the designer. Patient selection is paramount. Our data compares well with results from other uncemented total ankle replacements.