Introduction: Fractures of the femoral stem component in total hip Arthroplasty have been a well documented complication. The incidence over recent years has decreased due to improvements in surgical technique and implant design and manufacture.

Methods/Results: We report two cases of femoral stem fracture. Both occurred in CDH stems from the C-stem system (Depuy International, Leeds, UK). These are the first reported fractures in this stem. Both patients were women weighing 83kgs and 98kgs at the time of fracture giving them BMI’s of 31 and 41 respectively. In both cases the BMI had increased since the time of operation.

Discussion: The design of the CDH stem is fundamentally different from the rest of the standard stems with absence of the medial strut. In addition to this factor, both stems fractured through the insertion hole which acted as a stress raiser. Finally both patients BMI’s were above 25. At the time of operation no weight limit was imposed on this prosthesis.

We conclude that if possible, a standard C-stem should be inserted but if a CDH stem is used attention to patients’ weight is paramount.

This is a prospective study looking at 116 consecutive total hip replacements in 110 patients using the C-Stem total hip replacement system (Depuy International, Leeds, UK) between March 2000 and October 2002. This is the first documented study of results of the C-Stem outside Wrightington Hospital where it was developed.

There were 69 females and 41 male patients. Average age was 66 years (Range 32 – 89 years). 64 patients had a right hip replacement, 52 patients had a left hip replacement and 6 were bilateral. The duration of follow up was from 24 to 55 months, with an average of 38.75 months.

All patients had a cemented C-stem via a posterior approach. 107 with a metal head and 9 with a ceramic head. Cemented, all polyethylene cups were used. 82 hips had an Opera cup inserted and 34 had an Ogee cup inserted. Palacos R with Gentamicin was used for the cement.

103 femoral stems were neutral.12 stems were in varus (5–10 degrees) and 1 stem was in valgus (5–10degrees). No stems were greater than 10 degrees in either direction. There were no lucencies in any of the zones described by Gruen. The average amount of subsidence of the stem was 0.86mm (range 0–4mm).

The average cup angle was 44.29 degrees (SD = +/− 4.85). 8 acetabular components had a 0.5mm lucent area in zone 1 and 2 acetabular components had 1mm lucent area in zone 1. All of these lucencies were present on the immediate postoperative x-ray and none were progressive.

There were no lucencies in the other zones. There have been no incidences of deep infection, fatal P.E, dislocation or revision.

We conclude that the C-Stem has produced excellent results in the short term in keeping with the criteria of the NICE guidelines.