We present the histological findings of bone retrieved from beneath the femoral components of failed metal-on-metal hip resurfacing arthroplasties. Of a total of 377 patients who underwent resurfacing arthroplasty, 13 required revision; for fracture of the femoral neck in eight, loosening of a component in three and for other reasons in two. None of these cases had shown histological evidence of osteonecrosis in the femoral bone at the time of the initial implantation.

Bone from the remnant of the femoral head showed changes of osteonecrosis in all but one case at revision. In two cases of fracture which occurred within a week of implantation, the changes were compatible with early necrosis of the edge of the fracture. In the remaining six fractures, there were changes of established osteonecrosis. In all but one of the non-fracture cases, patchy osteonecrosis was seen.

We conclude that histological evidence of osteonecrosis is a common finding in failed resurfaced hips. Given that osteonecrosis is extensive in resurfaced femoral heads which fail by fracture, it is likely to play a role in the causation of these fractures.

Fracture of the femur in association with total hip arthroplasty is a challenging complication that has been well described. A variety of surgical treatment options have been reported. We present our experience of the Kent hip prosthesis in the management of periprosthetic femoral fractures.

We reviewed all patients (46) who had a Kent hip inserted for a periprosthetic femoral fracture. This group consisted of 16 males and 30 females of average age 73 years (43–96 years) at the time of fracture. Follow up ranged from 2 to 85 months (average, 4 years).

In 26 cases the primary prosthesis was a Charnley stem. Of the remaining cases the primary prostheses were as follows: 6 Austin Moore prostheses, 5 Howse, 4 Custom, 1 Exeter, 1 DHS, 1 Richards and 1 Thompson stem. There were 6 intraoperative fractures. Of the postoperative fractures forty-four were associated with a traumatic event. Time to fracture varied from 3 weeks to 20 years (average, 8 years). Prior to fracture 42 patients were living in their own home and 24 patients were mobile unaided. Twenty patients had pain prior to their fracture. The majority of patients were deemed ASA grade II or III. Thirty fractures were Johanssen type II, 14 type I, and 2 type III.

At the time of surgery, 32 patients had a loose stem and/or cup. Operating time was on average 143 minutes (range, 65–235 minutes) and intraoperative transfusion requirements ranged from 0–7 units of packed red cells (average, 3 units). Duration of hospital stay was on average 23 days (range, 7–77 days). Two patients developed superficial wound infections, six patients dislocated their prosthesis and one patient developed a chronic wound sinus.

In 34 cases fracture union was complete at latest review. Three patients required revision surgery for stem breakage and in 10 cases there was evidence of screw breakage.

At latest review, of the 31 patients that could be contacted 18 are still resident in their own homes. Twenty-six patients require the use of a walking aid (most commonly one stick). Ten patients have ongoing pain in relation to their operated hip.

In conclusion, we feel that the Kent hip prosthesis is a useful surgical option in the one-stage management of periprosthetic femoral fractures.

We performed arthrodesis with a cobra head compression plate in 18 young adults with severely degenerative arthritis of the hip. The aetiology was trauma in 4 patients, sepsis in 3, slipped upper femoral epiphysis in 3, Perthes disease in one, acute lymphblastic lymphoma in one, alcohol related avascular necrosis in 2, epiphyseal dysplasia in one, multiple osteochondromatosis in one, (bilateral) idiopathic chondrolysis in one and in the remaining case there was no apparent cause. At a mean follow up of 4 years 14 patients were complaining of back pain compared to 4 patients preoperatively. Preoperatively 4 patients had ipsilateral knee pain compared to 5 patients postoperatively. Four patients complained of pain at rest or night. Eleven of the 18 patients have returned to work. The average score of satisfaction on a scale of zero to ten was 7.2, with only 3 patients giving a mark of 4 and below.

The management of osteoarthritis of the hip in the young adult is challenging and arthrodesis of the hip is a reasonable option for the very painful arthritic hip.

Isolated patello-femoral osteoarthritis has been reported to occur in approximately 5% of patients with gonarthrosis of the knee. We present the results of the surgical management of this disorder in our unit. Thirty-one patients (33 knees) with symptomatic patello-femoral osteoarthritis and minimal tibio-femoral changes underwent LCS total knee replacement without patellar resurfacing.

Average age was 73 years (range, 58–89 years) with a female to male ratio of 5: 1. Average follow-up was 20 months (range, 12–40 months). All except four patients had grade 3 or 4 patello-femoral osteoarthritis according to the classification by Sperner et al.

Preoperatively, all patients had significant knee pain. Sleep disturbance was reported in 21 patients. All but 10 patients required walking aids. Average range of motion was 108° (range, 80°–125°).

At latest review, 21 knees are pain-free, the remaining 12 knees describing only occasional knee pain. Two patients continue to have night pain. Average range of motion was 104° (range, 700 – 135°). Lateral patellar tilt improved in all but five knees by an average of 7° (range, 10–26°). Patellar congruency improved in all but three knees by an average of 18% (range, 3–63%). None of the patients to date have required revision surgery. We suggest that knee arthroplasty without patellar resurfacing is an effective option in older patients with isolated patello-femoral osteoarthritis.