Tönnis triple pelvic osteotomy is an accepted technique to correct acetabular dysplasia and degenerative labral pathology. A series of 409 consecutive patients who underwent a triple pelvic osteotomy between 1987 and 1999 were followed for a mean of 7.1 years (2 to 15). Five patients (1.2%), all women, developed a double nonunion and required revision, which involved excision of the pseudarthrosis, autologous bone grafting and osteosynthesis with screws or reconstruction plates. Bony healing was achieved in all after a mean of 7.8 months.

We have investigated the factors which affect the progression of osteoarthritis after rotational acetabular osteotomy (RAO).

Between 1984 and 1998, we treated 60 dysplastic hips by RAO. The mean age at surgery was 31.6 years (13 to 51) and the mean period of follow-up was 4.6 years (2 to 9.5). The thickness of the articular cartilage on the weight-bearing area, pre- and postoperative acetabular cover, and the sphericity of the femoral head were used for radiological assessment.

The osteoarthritis did not progress in 39 hips. Significant factors which affected the radiological grade included sphericity of the femoral head and the postoperative acetabular cover. The surgical approach and preoperative acetabular cover did not affect the progression of osteoarthritis. Patients were divided into two groups according to the surgical approach used, either conventional (23 hips) or modified (37 hips). Significant factors included the postoperative acetabular cover in the modified approach, and the sphericity of the femoral head in the conventional approach.

It is critical that the postoperative cover is sufficient, especially when RAO is carried out using our modified technique.

Removal of well-fixed, cementless, acetabular components during revision arthroplasty remains a challenging problem. Further damage to host bone may limit options for reconstruction and compromise the long-term result of the revision operation. We report the results of 31 hips with well-fixed, cementless sockets which were removed using a new cup extraction system. In all hips the socket was removed without difficulty and with minimal further bone loss.

The treatment of osteonecrosis of the femoral head (FHN) is controversial. It mainly occurs in young patients in whom total hip replacement is best avoided because of an increased risk of revision. The objective of this long-term follow-up study was to evaluate the outcome of intertrochanteric flexion osteotomy as a hip joint preserving operation for FHN.

Over a 19-year period we carried out 70 intertrochanteric flexion osteotomies for FHN in 64 patients. The mean follow-up was 10.4 years (3.0 to 20.3). The overall mean Harris hip score increased from 51 points preoperatively to 71 points postoperatively. Six patients (9%) developed early postoperative complications. A total of 19 hips (27%) underwent total hip arthroplasty at a mean of 8.7 years after osteotomy. The five-year survival rate was 90%. Survival rates of hips in Ficat stage 2 were higher than those in stages 3 or 4. Hips with a preoperative necrotic angle of < 200° had a better survival probability than those with a necrotic angle > 200°. Our findings suggest that flexion osteotomy is a safe and effective procedure in Ficat stage 2 and 3 FHN, preferably with a necrotic angle of < 200°.

Between 1995 and 1997 we undertook 40 bipolar hip arthroplasties in 35 patients with dysplastic osteoarthritis. The steep and shallow acetabulum was excavated and the bipolar socket was placed high with an adjustment of leg-length. At follow-up of between five and seven years, there were 19 excellent, 16 good and five fair results according to the scoring system of Merle d’Aubigné and Postel. The mean radiographic superior migration of the bipolar socket was 2.1 mm (0 to 10). Osteolysis was noted in three hips within three years of the operation. Abduction on weight-bearing was recorded in 24 hips and the bipolar system was found to be functioning predominantly between the inner bearing and the metal femoral head in 20.

We retrospectively reviewed 45 hip arthroplasties which were performed over a period of 20 years in 38 patients with cirrhosis of the liver. There was a high perioperative 30-day complication rate (26.7%). Advanced cirrhosis was associated with a higher risk of complications (p = 0.004) as also was increased age, a high level of creatinine, a low level of albumin, a low platelet count, ascites, encephalopathy and an increased operative blood loss. The survival of the prosthesis at five years was 77.8% and infection was a major cause of failure.

In view of the high rate of early complications and the limited longevity of the prosthesis, surgeons who perform hip arthroplasty on such patients should counsel them appropriately preoperatively.

We analysed one surgeon’s attempt to reconstruct the hip in 66 patients (84 hips) with chronic dislocation and to restore the height of the centre of rotation above the transverse teardrop line, the bodyweight lever arm, the abductor lever arm, and the abductor angle to normal. The outcome was assessed using a patient profile at 0, 10 and 20 years, a clinical assessment of pain, mobility and the range of active movement. We measured the work done by active movement against gravity, radiological signs of loosening, migration and subsidence, and the need for revision. We used survival at ten years and revision as the endpoint.

The incidence of complications was higher than in arthroplasty for primary osteoarthritis of the hip, but the outcome was considered satisfactory. The advantages of a flanged cemented socket were demonstrated. A custom-made, laterally reduced, Charnley extra small CDH femoral prosthesis was used in certain cases.

We report the results of cancellous femoral impaction grafting with cement in revision hip arthroplasty in all patients from one centre who had undergone surgery more than five years previously. A total of 32 surgeons undertook femoral impaction grafting in 207 patients (226 hips). There were no deaths attributable to the revision surgery; 33 patients with 35 functioning hips died with less than five years’ follow-up. One patient was lost to follow-up. Two hips (1%) developed early postoperative infection. Of the 12 stems which underwent a further surgical procedure for aseptic failure, ten were for femoral fracture and two for loosening.

Survivorship with any further femoral operation as the endpoint was 90.5% (confidence intervals, 82 to 98) and using femoral reoperation for symptomatic aseptic loosening as the endpoint, the survivorship was 99.1% (confidence intervals, 96 to 100) at 10 to 11 years. As a consequence of the experience in this series, we have modified our technique with an increased use of longer stems with impacted allograft. Long stems are indicated when the host bone around the tip of a short stem is compromised, in patients with major loss of bone stock, or when a femoral fracture occurs.

The vertical-centre-anterior margin (VCA) angle quantifies the anterior cover of the femoral head. However, when the femoral head is deformed it may be difficult to identify its centre. We have therefore created a new index, the anterior acetabular head index (AAHI) which is measured on the false-profile radiograph. We measured the VCA and AAHI angles in 312 hips in which the centre-edge angle was > 25°. There were 250 patients, 86 men and 164 women, whose ages ranged from 20 to 65 years. The mean AAHI was 84.1% (81.7% in women and 88.5% in men). There was a correlation between the AAHI and VCA angles. Our data suggest that the AAHI is useful in the evaluation of anterior acetabular cover and that it is higher in men than in women.

We followed, prospectively, 77 patients (90 hips) with early-stage, non-traumatic osteonecrosis of the femoral head for a mean period of nine years. At the time of final review, 56 (62%) were symptomatic. Using the Cox model, the initial radiological stage, the progression of staging, the reduction in size of the lesions and the percentage of necrotic volume on MRI were identified as risk factors.

Using the Harris score of < 70 or surgery as the endpoint, the cumulative rates of survival were 60.0% at one year, 43.3% at two years, 38.9% at five years and 37.2% at ten years. Survival curves demonstrated that clinical deterioration could occur 90 months after the initial diagnosis, suggesting that asymptomatic patients should be followed carefully for several years. Radiological time-dependent reduction in size without progressive collapse may represent repair even when the collapse is minimal.

We prospectively investigated a consecutive series of ten patients undergoing a cemented primary total hip replacement (THR) for osteoarthritis in order to establish the elution characteristics of Simplex-tobramycin bone cement (Howmedica, Limerick, Ireland). Specimens of blood, urine and drainage fluid were collected for 72 hours postoperatively. Very high concentrations of tobramycin were found in the drainage fluid, with mean levels at one hour of 103 mg/l, which steadily declined to 15.1 mg/l after 48 hours. The mean serum tobramycin levels reached a peak of 0.94 mg/l at three hours and declined rapidly to 0.2 mg/l by 48 hours. The mean urinary tobramycin levels peaked at 57.8 mg/l at 12 hours with a rapid decline to 12.6 mg/l by 24 hours.

There was a direct correlation between the amount of tobramycin bone cement which was implanted and the amount of tobramycin systemically absorbed. Excellent local delivery was achieved with minimal systemic concentrations. Simplex-tobramycin bone cement is an efficient and safe method for the delivery of antibiotics after THR.

We reviewed 80 patients (87 hips) who were older than 80 years of age at the time of cementless total hip arthroplasty. An Alloclassic SL stem had been implanted in all patients. A variety of cementless acetabular components was used. After a mean follow-up of 69.3 months (39.2 to 94.1) 48 hips in 43 patients were analysed clinically and radiologically. One patient had sustained a traumatic periprosthetic fracture of the femur with subsequent exchange of the stem 73 months after operation. Thirty-two patients (34 hips) had died and five patients (five hips) were unavailable for follow-up because of health reasons (four patients) or lack of co-operation (one patient). If the endpoint is defined as removal of the prosthesis because of aseptic loosening, the survival rate was 100% for the cup and stem after 78 months. The mean Harris hip score was 81.9 points. Radiolucent lines and osteolysis were seldom found.

Metal-on-metal (MOM) is a commonly used bearing notable for its ‘suction fit’ when lubricated. In this study, we examined the capacity for MOM bearings to protect against dislocation after total hip replacement (THR).

We undertook a clinical investigation to compare the rate of dislocation of MOM bearings with those of ceramic-on-polyethylene (COP) bearings and found that one MOM bearing dislocated in a series of 109 hips (0.9%) compared with nine of 145 hips (6.2%) in the COP group (p = 0.02).

We also performed an in vitro investigation comparing the peak forces generated during forced separation of the two bearings of the same dimensions at velocities from 1 to 50 cm/s. This revealed that the MOM bearing generated significant resistance to separation at all velocities (maximum mean 24 N), whereas the COP did not (maximum mean 1.9 N, p < 0.001). We conclude that MOM bearings are more stable to dislocation than COP bearings as a result of the interfacial forces provided by a thin, lubricating fluid.

We examined the behaviour of alumina ceramic heads in 156 cemented total hip arthroplasties, at a minimum follow-up of eight years. They were divided into three groups according to the size of the femoral head; 22, 26, and 28 mm. We measured polyethylene wear radiologically using a computer-aided technique. The linear wear rate of polyethylene sockets for the 28 mm heads was high (0.156 mm/year), whereas those for the 22 and 26 mm heads were relatively low (0.090 and 0.098 mm/year, respectively). Moreover, the surface roughness data of retrieved femoral heads clearly showed maintenance of an excellent surface finish of the current alumina. We conclude that the alumina ceramic femoral heads currently used are associated with a reduced rate of polyethylene wear.

There are many reports concerning the aetiology and prophylaxis of deep-vein thrombosis (DVT) but little is known about its natural history. The purpose of our study was to identify the incidence and site of DVT, the risk factors for pulmonary embolism and the natural history of DVT after total hip replacement (THR) in patients who do not receive any form of prophylactic or therapeutic treatment for DVT.

Two hundred patients who had a primary THR were included: 100 had one-staged bilateral THR and 100 had unilateral THR and 150 implants were cemented and 150 cementless. Coagulation assays, a full blood count, blood typing and serum chemical profile tests were performed for all patients on three separate occasions. Bilateral simultaneous or unilateral venograms were performed on the sixth or seventh postoperative day and perfusion lung scans preoperatively and on the seventh or eighth postoperative day. Further venograms were performed in all patients who had thrombi six months later.

In the patients with bilateral THR, 52 (26%) venograms were positive for thrombi, while in the patients with unilateral THR 20 (20%) were positive (p = 0.89). In the patients with a cemented THR, 31 venograms (20.7%) were positive for thrombi, while in those with a cementless THR 41 (27.3%) were positive (p = 0.654). Further venograms in all 72 patients who had thrombi at six months after operation showed that they resolved completely and spontaneously regardless of their site and size. No patients had symptoms of pulmonary emboli and none were seen on the perfusion lung scans. Two patients died from unrelated causes.

Although the prevailing opinion is that patients with proximal venous thrombosis should be treated with anticoagulants, our study has shown that all thrombi regardless of their site and size resolve spontaneously without associated pulmonary embolism.

We used a trochanteric slide osteotomy (TSO) in 94 consecutive revision total hip arthroplasties (90 with replacement of both the cup and stem). This technique proved to be adequate for removing the components, with few complications (two minor fractures), and for implanting acetabular allografts (18%) and reinforcement devices (23%). Trochanteric union was obtained in most patients (96%), even in those with septic loosening (18/19), major femoral osteolysis (32/32), or previous trochanteric osteotomy (17/18). TSO is versatile, since it can be extended by a femoral flap (four cases) or a distal femoral window (eight cases). Despite significant bone loss, in 24% of the femora and 57% of the acetabula, favourable midterm results were achieved and only six reoperations were required, including two for trochanteric nonunion and two for loosening. It leaves the lateral femoral cortex intact so that a stem longer than 200 mm was needed in only 25% of patients. This is a considerable advantage compared with the extended trochanteric osteotomy in which the long lateral flap (12 to 14 cm) requires an average length of stem of 220 mm beyond the calcar.

TSO provides an approach similar in size to the standard trochanteric osteotomy but with a rate of nonunion of 4% versus 15%. It reduces the risk of difficulties with removal of the stem, and removes the need for routine distal anchoring of long revision stems. The limited distal femoral compromise is very important in patients with a long life expectancy.

Although alumina has been used in orthopaedic surgery since the 1970s, the long-term clinical results of zirconia have not been well documented in vivo. We studied hips with these two different ceramics during the same period and with a minimum follow-up of ten years. Because the size of the alumina and zirconia heads was different, hips with 32 mm alumina heads and those with 28 mm zirconia heads were compared with control hips with stainless-steel heads of the same size. Our aim was to compare the two ceramics.

There was an increased linear rate of penetration of the femoral heads into the liner between years five and 12 for the zirconia and the stainless-steel groups. This was severe in the zirconia group (0.4 mm/year compared with 0.13 mm/year for the stainless-steel group). During the same 12-year period there was, however, no significant change in the rate of wear in the alumina group (0.07 mm/year). The mean wear at the most recent follow-up was 1360 mm³ for the 28 mm zirconia group, 683 mm³ for the 28 mm stainless-steel group, 755 mm³ for the 32 mm alumina group and 1314 mm³ for the 32 mm stainless-steel group. The monoclinic content rose on the surface of three zirconia heads which were retrieved at revision. This change was associated with an increase in the surface roughness. A change in the roundness with an increase in the sphericity deviation was also observed both in the articular and non-articular parts of the femoral heads. The increase in rate of wear in the zirconia group was only evident after eight years and may be linked to a long-term biodegradation of zirconia in vivo, associated with the altered roughness and roundness which was observed on the retrieved heads.

We compared patient satisfaction with surgeon satisfaction after total hip arthroplasty (THA) in a group of 193 patients (200 THAs, mean follow-up six years) using a visual analogue scale (VAS), and two objective and two subjective scoring systems. We also determined the survival rate with different endpoints. For the 121 hips available for clinical follow-up, we did not find a significant difference in satisfaction between patient and surgeon. In a subgroup with low patient satisfaction, the surgeon was more satisfied than the patient (p = 0.04). The correlation between the patient satisfaction VAS and the different subjective and objective scoring systems suggests that pain during activity is the most important factor for the patient. The survivorship at six years decreased from 96.6% to 83.7% if dissatisfaction (VAS > 20) was added to revision as an endpoint in the survival analysis. The patient satisfaction VAS provides additional information to evaluate the outcome of THA. We recommend the use of both subjective and objective scoring systems to evaluate the outcome of THA.

We carried out a histological study of a proximally hydroxyapatite (HA)-coated femoral component, retrieved after 9.5 years of good function. The HA coating had completely degraded. Bone was in direct contact with the titanium surface in all the areas which had been coated, with no interposing fibrous tissue. There were no signs of particles, third-body wear, adverse tissue reactions or osteolysis. Bone remodelling was evident by the presence of resorption lacunae; tetracycline labelling showed bone laid down six years after implantation.

The loss of the HA-coating had no negative effect on the osseo-integration of the stem. We conclude that the HA coating contributes to the fixation of the implant and that its degradation does not adversely affect the long-term fixation.

We have prospectively studied the wear of enhanced ultra-high molecular-weight polyethylene (Hylamer) in combination with a zirconia femoral head of 22.225 mm diameter on a cemented, triple-tapered, collarless, polished stem, the C Stem.

The 71 patients who underwent total hip arthroplasty had a mean follow-up of six years (3 to 8). No patient died or was lost to follow-up. The clinical results were excellent with 96% of patients satisfied. There were no revisions. Two cups were considered to be loose radiologically. One was avulsed from the cement in a skiing accident, with a periprosthetic fracture of the femur, but has remained stable for more than seven years. One femur shows radiological appearances which are compatible with a healing infection. One femoral component is at risk of loosening. The mean rate of penetration of the cup was 0.22 mm/year (0.06 to 0.55).

Our results appear to be within the guidelines set by the National Institute of Clinical Excellence. We have discontinued the use of Hylamer despite excellent clinical results and no revisions to date because the high initial rates of penetration did not settle to the expected low levels within the anticipated time.